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Canale V, Spalinger MR, Alvarez R, Sayoc-Becerra A, Sanati G, Manz S, Chatterjee P, Santos AN, Lei H, Jahng S, Chu T, Shawki A, Hanson E, Eckmann L, Ouellette AJ, McCole DF. PTPN2 is a Critical Regulator of Ileal Paneth Cell Viability and Function in Mice. Cell Mol Gastroenterol Hepatol 2023; 16:39-62. [PMID: 37030630 DOI: 10.1016/j.jcmgh.2023.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 03/29/2023] [Accepted: 03/30/2023] [Indexed: 04/10/2023]
Abstract
BACKGROUND & AIMS Loss-of-function variants in the protein tyrosine phosphatase non-receptor type 2 (PTPN2) gene are associated with increased risk of Inflammatory Bowel Disease (IBD). We recently showed that Ptpn2 is critical for intestinal epithelial cell (IEC) barrier maintenance, IEC-macrophage communication, and modulation of the gut microbiome in mice restricting expansion of a small intestinal pathobiont associated with IBD. Here, we aimed to identify how Ptpn2-loss affects ileal IEC subtypes and their function in vivo. METHODS Constitutive Ptpn2-wild-type (WT), heterozygous (HET) and knockout (KO) mice, as well as mice with inducible deletion of Ptpn2 in IECs, were used in the study. Investigation was performed using imaging techniques, flow cytometry, enteroid culture, and analysis of gene and protein levels of IEC markers. RESULTS Partial transcriptome analysis revealed that Paneth cell-associated antimicrobial peptides (AMP) Lyz1, Pla2g2a and Defa6 expression, were markedly downregulated in Ptpn2-KO mice compared with WT and HET. In parallel, Paneth cell numbers were reduced, their endoplasmic reticulum (ER) architecture was disrupted, and the ER stress protein, CHOP, was increased in Ptpn2-KO mice. Despite reduced Paneth cell number, flow cytometry showed increased expression of the Paneth cell-stimulatory cytokines IL-22 and IFN-γ+ in CD4+ T-cells isolated from Ptpn2-KO ileum. Key findings in constitutive Ptpn2-KO mice were confirmed in epithelium-specific Ptpn2ΔIEC mice, which also showed impaired lysozyme protein levels in Paneth cells compared to Ptpn2fl/fl control mice. CONCLUSION Constitutive Ptpn2-deficiency affects Paneth cell viability and compromises Paneth cell-specific AMP production. The observed effects may contribute to the increased susceptibility to intestinal infection and dysbiosis in these mice.
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Affiliation(s)
- Vinicius Canale
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, USA;; Biochemistry and Molecular Biology Department, University of California Riverside, Riverside, California, USA;; CAPES Foundation, Ministry of Education of Brazil, Brasília - DF - 70040-020, Brazil
| | - Marianne R Spalinger
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, USA;; Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Switzerland
| | - Rocio Alvarez
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, USA
| | - Anica Sayoc-Becerra
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, USA
| | - Golshid Sanati
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, USA
| | - Salomon Manz
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, USA;; Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Switzerland
| | - Pritha Chatterjee
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, USA;; Biochemistry and Molecular Biology Department, University of California Riverside, Riverside, California, USA
| | - Alina N Santos
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, USA
| | - Hillmin Lei
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, USA
| | - Sharon Jahng
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, USA
| | - Timothy Chu
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, USA
| | - Ali Shawki
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, USA
| | - Elaine Hanson
- Division of Gastroenterology, University of California, San Diego, La Jolla, CA, USA
| | - Lars Eckmann
- Division of Gastroenterology, University of California, San Diego, La Jolla, CA, USA
| | - André J Ouellette
- Department of Pathology and Laboratory Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Declan F McCole
- Division of Biomedical Sciences, University of California Riverside, Riverside, California, USA;.
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2
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Tongaonkar P, Trinh KK, Ouellette AJ, Selsted ME. Inhibition of miR-146a Expression and Regulation of Endotoxin Tolerance by Rhesus Theta-Defensin-1. Mediators Inflamm 2023; 2023:8387330. [PMID: 37101596 PMCID: PMC10125762 DOI: 10.1155/2023/8387330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 03/07/2023] [Accepted: 03/30/2023] [Indexed: 04/28/2023] Open
Abstract
Theta- (θ-) defensins are pleiotropic host defense peptides with antimicrobial- and immune-modulating activities. Immune stimulation of cells with lipopolysaccharide (LPS, endotoxin) activates proinflammatory gene expression and cytokine secretion, both of which are attenuated by rhesus theta-defensin-1 (RTD-1) inhibition of NF-κB and MAP kinase pathways. Endotoxin tolerance is a condition that ensues when cells have an extended primary exposure to low levels of LPS, resulting in resistance to a subsequent LPS challenge. Recognition of LPS by Toll-like receptor-4 (TLR4) activates NF-κB, elevating levels of microRNA-146a (miR-146a), which targets IRAK1 and TRAF6 transcripts to reduce their protein levels and inhibits TLR signaling on secondary LPS stimulation. Here, we report that RTD-1 suppressed the expression of miR-146a and stabilized the IRAK1 protein in immune-stimulated, monocytic THP-1 cells. Cells that had primary exposure to LPS became endotoxin-tolerant, as evident from their failure to secrete TNF-α upon secondary endotoxin challenge. However, cells incubated with RTD-1 during the primary LPS stimulation secreted TNF-α after secondary LPS stimulation in an RTD-1 dose-dependent manner. Consistent with this, compared to the control treatment, cells treated with RTD-1 during primary LPS stimulation had increased NF-κB activity after secondary LPS stimulation. These results show that RTD-1 suppresses endotoxin tolerance by inhibiting the NF-κB pathway and demonstrates a novel inflammatory role for RTD-1 that is mediated by the downregulation of miR-146a during the innate immune response.
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Affiliation(s)
- Prasad Tongaonkar
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Katie K. Trinh
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - André J. Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- USC Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA
| | - Michael E. Selsted
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- USC Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA
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3
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Clark RJ, Phan TH, Song A, Ouellette AJ, Conibear AC, Rosengren KJ. A conserved β‐bulge glycine residue facilitates folding and increases stability of the mouse α‐defensin cryptdin‐4. Pept Sci (Hoboken) 2021. [DOI: 10.1002/pep2.24250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Richard J. Clark
- The University of Queensland, School of Biomedical Sciences Brisbane Queensland Australia
| | - Thanh Huyen Phan
- The University of Queensland, School of Biomedical Sciences Brisbane Queensland Australia
| | - Angela Song
- The University of Queensland, School of Biomedical Sciences Brisbane Queensland Australia
| | - André J. Ouellette
- Department of Pathology and Laboratory Medicine and USC Norris Comprehensive Cancer Center Keck School of Medicine, University of Southern California Los Angeles California USA
| | - Anne C. Conibear
- The University of Queensland, School of Biomedical Sciences Brisbane Queensland Australia
| | - K. Johan Rosengren
- The University of Queensland, School of Biomedical Sciences Brisbane Queensland Australia
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4
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Basso V, Tran DQ, Ouellette AJ, Selsted ME. Host Defense Peptides as Templates for Antifungal Drug Development. J Fungi (Basel) 2020; 6:jof6040241. [PMID: 33113935 PMCID: PMC7711597 DOI: 10.3390/jof6040241] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 12/15/2022] Open
Abstract
Current treatment for invasive fungal diseases is limited to three classes of antifungal drugs: azoles, polyenes, and echinocandins. The most recently introduced antifungal class, the echinocandins, was first approved nearly 30 years ago. The limited antifungal drug portfolio is rapidly losing its clinical utility due to the inexorable rise in the incidence of invasive fungal infections and the emergence of multidrug resistant (MDR) fungal pathogens. New antifungal therapeutic agents and novel approaches are desperately needed. Here, we detail attempts to exploit the antifungal and immunoregulatory properties of host defense peptides (HDPs) in the design and evaluation of new antifungal therapeutics and discuss historical limitations and recent advances in this quest.
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Affiliation(s)
- Virginia Basso
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA; (V.B.); (D.Q.T.); (A.J.O.)
| | - Dat Q. Tran
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA; (V.B.); (D.Q.T.); (A.J.O.)
- Oryn Therapeutics, Vacaville, CA 95688, USA
| | - André J. Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA; (V.B.); (D.Q.T.); (A.J.O.)
- Norris Comprehensive Cancer Center of the University of Southern California, Los Angeles, CA 90089, USA
| | - Michael E. Selsted
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA; (V.B.); (D.Q.T.); (A.J.O.)
- Oryn Therapeutics, Vacaville, CA 95688, USA
- Norris Comprehensive Cancer Center of the University of Southern California, Los Angeles, CA 90089, USA
- Correspondence:
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5
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Tongaonkar P, Punj V, Subramanian A, Tran DQ, Trinh KK, Schaal JB, Laragione T, Ouellette AJ, Gulko PS, Selsted ME. RTD-1 therapeutically normalizes synovial gene signatures in rat autoimmune arthritis and suppresses proinflammatory mediators in RA synovial fibroblasts. Physiol Genomics 2019; 51:657-667. [PMID: 31762409 DOI: 10.1152/physiolgenomics.00066.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Rhesus theta defensin-1 (RTD-1), a macrocyclic immunomodulatory host defense peptide from Old World monkeys, is therapeutic in pristane-induced arthritis (PIA) in rats, a model of rheumatoid arthritis (RA). RNA-sequence (RNA-Seq) analysis was used to interrogate the changes in gene expression in PIA rats, which identified 617 differentially expressed genes (DEGs) in PIA synovial tissue of diseased rats. Upstream regulator analysis showed upregulation of gene expression pathways regulated by TNF, IL1B, IL6, proinflammatory cytokines, and matrix metalloproteases (MMPs) involved in RA. In contrast, ligand-dependent nuclear receptors like the liver X-receptors NR1H2 and NR1H3 and peroxisome proliferator-activated receptor gamma (PPARG) were downregulated in arthritic synovia. Daily RTD-1 treatment of PIA rats for 1-5 days following disease presentation modulated 340 of the 617 disease genes, and synovial gene expression in PIA rats treated 5 days with RTD-1 closely resembled the gene signature of naive synovium. Systemic RTD-1 inhibited proinflammatory upstream regulators such as TNF, IL1, and IL6 and activated antiarthritic ligand-dependent nuclear receptor pathways, including PPARG, NR1H2, and NR1H3, that were suppressed in untreated PIA rats. RTD-1 also inhibited proinflammatory responses in IL-1β-stimulated human RA fibroblast-like synoviocytes (FLS) in vitro and diminished expression of human orthologs of disease genes that are induced in rat PIA synovium. Thus, the antiarthritic mechanisms of systemic RTD-1 include homeostatic regulation of arthritogenic gene networks in a manner that correlates temporally with clinical resolution of rat PIA.
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Affiliation(s)
- Prasad Tongaonkar
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Vasu Punj
- Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Akshay Subramanian
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Dat Q Tran
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California.,Oryn Therapeutics, LLC, Vacaville, California
| | - Katie K Trinh
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Justin B Schaal
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Teresina Laragione
- Division of Rheumatology, Department of Medicine, Icahn School of Medicine at Mt. Sinai, New York, New York and
| | - André J Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California.,USC Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Percio S Gulko
- Division of Rheumatology, Department of Medicine, Icahn School of Medicine at Mt. Sinai, New York, New York and
| | - Michael E Selsted
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California.,Oryn Therapeutics, LLC, Vacaville, California.,USC Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California
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6
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Basso V, Tran DQ, Schaal JB, Tran P, Eriguchi Y, Ngole D, Cabebe AE, Park AY, Beringer PM, Ouellette AJ, Selsted ME. Rhesus Theta Defensin 1 Promotes Long Term Survival in Systemic Candidiasis by Host Directed Mechanisms. Sci Rep 2019; 9:16905. [PMID: 31729441 PMCID: PMC6858451 DOI: 10.1038/s41598-019-53402-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/30/2019] [Indexed: 12/21/2022] Open
Abstract
Invasive candidiasis is an increasingly frequent cause of serious and often fatal infections in hospitalized and immunosuppressed patients. Mortality rates associated with these infections have risen sharply due to the emergence of multidrug resistant (MDR) strains of C. albicans and other Candida spp., highlighting the urgent need of new antifungal therapies. Rhesus theta (θ) defensin-1 (RTD-1), a natural macrocyclic antimicrobial peptide, was recently shown to be rapidly fungicidal against clinical isolates of MDR C. albicans in vitro. Here we found that RTD-1 was rapidly fungicidal against blastospores of fluconazole/caspofungin resistant C. albicans strains, and was active against established C. albicans biofilms in vitro. In vivo, systemic administration of RTD-1, initiated at the time of infection or 24 h post-infection, promoted long term survival in candidemic mice whether infected with drug-sensitive or MDR strains of C. albicans. RTD-1 induced an early (4 h post treatment) increase in neutrophils in naive and infected mice. In vivo efficacy was associated with fungal clearance, restoration of dysregulated inflammatory cytokines including TNF-α, IL-1β, IL-6, IL-10, and IL-17, and homeostatic reduction in numbers of circulating neutrophils and monocytes. Because these effects occurred using peptide doses that produced maximal plasma concentrations (Cmax) of less than 1% of RTD-1 levels required for in vitro antifungal activity in 50% mouse serum, while inducing a transient neutrophilia, we suggest that RTD-1 mediates its antifungal effects in vivo by host directed mechanisms rather than direct fungicidal activity. Results of this study suggest that θ-defensins represent a new class of host-directed compounds for treatment of disseminated candidiasis.
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Affiliation(s)
- Virginia Basso
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Dat Q Tran
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Oryn Therapeutics, Vacaville, California, United States of America
| | - Justin B Schaal
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Patti Tran
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Yoshihiro Eriguchi
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Department of Clinical Immunology and Rheumatology/Infectious DiseaseKyushu University HospitalDepartment of Medicine and Biosystemic ScienceKyushu University Graduate School of Medical Science, Fukuoka, Japan
| | - Diana Ngole
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Anthony E Cabebe
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - A Young Park
- Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, United States of America
| | - Paul M Beringer
- Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, United States of America
| | - André J Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Norris Comprehensive Cancer Center of the University of Southern California, Los Angeles, California, United States of America
| | - Michael E Selsted
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America.
- Oryn Therapeutics, Vacaville, California, United States of America.
- Norris Comprehensive Cancer Center of the University of Southern California, Los Angeles, California, United States of America.
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7
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Eriguchi Y, Nakamura K, Yokoi Y, Sugimoto R, Takahashi S, Hashimoto D, Teshima T, Ayabe T, Selsted ME, Ouellette AJ. Essential role of IFN-γ in T cell-associated intestinal inflammation. JCI Insight 2018; 3:121886. [PMID: 30232288 DOI: 10.1172/jci.insight.121886] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 08/14/2018] [Indexed: 12/11/2022] Open
Abstract
Paneth cells contribute to small intestinal homeostasis by secreting antimicrobial peptides and constituting the intestinal stem cell (ISC) niche. Certain T cell-mediated enteropathies are characterized by extensive Paneth cell depletion coincident with mucosal destruction and dysbiosis. In this study, mechanisms of intestinal crypt injury have been investigated by characterizing responses of mouse intestinal organoids (enteroids) in coculture with mouse T lymphocytes. Activated T cells induced enteroid damage, reduced Paneth cell and Lgr5+ ISC mRNA levels, and induced Paneth cell death through a caspase-3/7-dependent mechanism. IFN-γ mediated these effects, because IFN-γ receptor-null enteroids were unaffected by activated T cells. In mice, administration of IFN-γ induced enteropathy with crypt hyperplasia, villus shortening, Paneth cell depletion, and modified ISC marker expression. IFN-γ exacerbated radiation enteritis, which was ameliorated by treatment with a selective JAK1/2 inhibitor. Thus, IFN-γ induced Paneth cell death and impaired regeneration of small intestinal epithelium in vivo, suggesting that IFN-γ may be a useful target for treating defective mucosal regeneration in enteric inflammation.
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Affiliation(s)
- Yoshihiro Eriguchi
- Department of Pathology and Laboratory Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Kiminori Nakamura
- Department of Cell Biological Science, Graduate School of Life Science, Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Yuki Yokoi
- Department of Cell Biological Science, Graduate School of Life Science, Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Rina Sugimoto
- Department of Cell Biological Science, Graduate School of Life Science, Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Shuichiro Takahashi
- Department of Hematology, Hokkaido University Faculty of Medicine, Sapporo, Japan
| | - Daigo Hashimoto
- Department of Hematology, Hokkaido University Faculty of Medicine, Sapporo, Japan
| | - Takanori Teshima
- Department of Hematology, Hokkaido University Faculty of Medicine, Sapporo, Japan
| | - Tokiyoshi Ayabe
- Department of Cell Biological Science, Graduate School of Life Science, Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Michael E Selsted
- Department of Pathology and Laboratory Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - André J Ouellette
- Department of Pathology and Laboratory Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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8
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Schaal JB, Maretzky T, Tran DQ, Tran PA, Tongaonkar P, Blobel CP, Ouellette AJ, Selsted ME. Macrocyclic θ-defensins suppress tumor necrosis factor-α (TNF-α) shedding by inhibition of TNF-α-converting enzyme. J Biol Chem 2018; 293:2725-2734. [PMID: 29317500 DOI: 10.1074/jbc.ra117.000793] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/03/2018] [Indexed: 12/16/2022] Open
Abstract
Theta-defensins (θ-defensins) are macrocyclic peptides expressed exclusively in granulocytes and selected epithelia of Old World monkeys. They contribute to anti-pathogen host defense responses by directly killing a diverse range of microbes. Of note, θ-defensins also modulate microbe-induced inflammation by affecting the production of soluble tumor necrosis factor (sTNF) and other proinflammatory cytokines. Here, we report that natural rhesus macaque θ-defensin (RTD) isoforms regulate sTNF cellular release by inhibiting TNF-α-converting enzyme (TACE; also known as adisintegrin and metalloprotease 17; ADAM17), the primary pro-TNF sheddase. Dose-dependent inhibition of cellular TACE activity by RTDs occurred when leukocytes were stimulated with live Escherichia coli cells as well as numerous Toll-like receptor agonists. Moreover, the relative inhibitory potencies of the RTD isoforms strongly correlated with their suppression of TNF release by stimulated blood leukocytes and THP-1 monocytes. RTD isoforms also inhibited ADAM10, a sheddase closely related to TACE. TACE inhibition was abrogated by introducing a single opening in the RTD-1 backbone, demonstrating that the intact macrocycle is required for enzyme inhibition. Enzymologic analyses showed that RTD-1 is a fast binding, reversible, non-competitive inhibitor of TACE. We conclude that θ-defensin-mediated inhibition of pro-TNF proteolysis by TACE represents a rapid mechanism for the regulation of sTNF and TNF-dependent inflammatory pathways. Molecules with structural and functional features mimicking those of θ-defensins may have clinical utility as TACE inhibitors for managing TNF-driven diseases.
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Affiliation(s)
- Justin B Schaal
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90089
| | - Thorsten Maretzky
- Hospital for Special Surgery, Weill Cornell Medicine, New York, New York 10021; Inflammation Program and Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Dat Q Tran
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90089
| | - Patti A Tran
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90089
| | - Prasad Tongaonkar
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90089
| | - Carl P Blobel
- Hospital for Special Surgery, Weill Cornell Medicine, New York, New York 10021
| | - André J Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90089; Norris Comprehensive Cancer Center of the University of Southern California, Los Angeles, California 90033
| | - Michael E Selsted
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90089; Norris Comprehensive Cancer Center of the University of Southern California, Los Angeles, California 90033.
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9
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Schaal JB, Tran DQ, Subramanian A, Patel R, Laragione T, Roberts KD, Trinh K, Tongaonkar P, Tran PA, Minond D, Fields GB, Beringer P, Ouellette AJ, Gulko PS, Selsted ME. Suppression and resolution of autoimmune arthritis by rhesus θ-defensin-1, an immunomodulatory macrocyclic peptide. PLoS One 2017; 12:e0187868. [PMID: 29145473 PMCID: PMC5690597 DOI: 10.1371/journal.pone.0187868] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 10/30/2017] [Indexed: 12/13/2022] Open
Abstract
θ-defensins constitute a family of macrocyclic peptides expressed exclusively in Old World monkeys. The peptides are pleiotropic effectors of innate immunity, possessing broad spectrum antimicrobial activities and immunoregulatory properties. Here we report that rhesus θ-defensin 1 (RTD-1) is highly effective in arresting and reversing joint disease in a rodent model of rheumatoid arthritis (RA). Parenteral RTD-1 treatment of DA/OlaHsd rats with established pristane-induced arthritis (PIA) rapidly suppressed joint disease progression, restored limb mobility, and preserved normal joint architecture. RTD-1 significantly reduced joint IL-1β levels compared with controls. RTD-1 dose-dependently inhibited fibroblast-like synoviocyte (FLS) invasiveness and FLS IL-6 production. Consistent with the inhibition of FLS invasiveness, RTD-1 was a potent inhibitor of arthritogenic proteases including ADAMs 17 and 10 which activate TNFα, and inhibited matrix metalloproteases, and cathepsin K. RTD-1 was non-toxic, non-immunogenic, and effective when administered as infrequently as once every five days. Thus θ-defensins, which are absent in humans, have potential as retroevolutionary biologics for the treatment of RA.
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Affiliation(s)
- Justin B. Schaal
- Department of Pathology & Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Dat Q. Tran
- Department of Pathology & Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Oryn Therapeutics, Vacaville, California, United States of America
| | - Akshay Subramanian
- Department of Pathology & Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Reshma Patel
- Children’s Hospital Los Angeles, Los Angeles, California, United States of America
| | - Teresina Laragione
- Division of Rheumatology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Kevin D. Roberts
- Department of Pathology & Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Katie Trinh
- Department of Pathology & Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Prasad Tongaonkar
- Department of Pathology & Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Patti A. Tran
- Department of Pathology & Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Dmitriy Minond
- Torrey Pines Institute for Molecular Studies, Port St Lucie, Florida, United States of America
| | - Gregg B. Fields
- Department of Chemistry & Biochemistry, Florida Atlantic University, Jupiter, Florida, United States of America
- The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Paul Beringer
- School of Pharmacy, University of Southern California, Los Angeles, California, United States of America
| | - André J. Ouellette
- Department of Pathology & Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Norris Comprehensive Cancer Center of the University of Southern California, Los Angeles, California, United States of America
| | - Percio S. Gulko
- Division of Rheumatology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Michael E. Selsted
- Department of Pathology & Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Norris Comprehensive Cancer Center of the University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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10
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Diaz-Ochoa VE, Lam D, Lee CS, Klaus S, Behnsen J, Liu JZ, Chim N, Nuccio SP, Rathi SG, Mastroianni JR, Edwards RA, Jacobo CM, Cerasi M, Battistoni A, Ouellette AJ, Goulding CW, Chazin WJ, Skaar EP, Raffatellu M. Salmonella Mitigates Oxidative Stress and Thrives in the Inflamed Gut by Evading Calprotectin-Mediated Manganese Sequestration. Cell Host Microbe 2017; 19:814-25. [PMID: 27281571 DOI: 10.1016/j.chom.2016.05.005] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 03/14/2016] [Accepted: 04/29/2016] [Indexed: 01/27/2023]
Abstract
Neutrophils hinder bacterial growth by a variety of antimicrobial mechanisms, including the production of reactive oxygen species and the secretion of proteins that sequester nutrients essential to microbes. A major player in this process is calprotectin, a host protein that exerts antimicrobial activity by chelating zinc and manganese. Here we show that the intestinal pathogen Salmonella enterica serovar Typhimurium uses specialized metal transporters to evade calprotectin sequestration of manganese, allowing the bacteria to outcompete commensals and thrive in the inflamed gut. The pathogen's ability to acquire manganese in turn promotes function of SodA and KatN, enzymes that use the metal as a cofactor to detoxify reactive oxygen species. This manganese-dependent SodA activity allows the bacteria to evade neutrophil killing mediated by calprotectin and reactive oxygen species. Thus, manganese acquisition enables S. Typhimurium to overcome host antimicrobial defenses and support its competitive growth in the intestine.
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Affiliation(s)
- Vladimir E Diaz-Ochoa
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA 92697-4025, USA; Institute for Immunology, University of California, Irvine, Irvine, CA 92697-4120, USA
| | - Diana Lam
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA 92697-4025, USA; Institute for Immunology, University of California, Irvine, Irvine, CA 92697-4120, USA
| | - Carlin S Lee
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA 92697-4025, USA; Institute for Immunology, University of California, Irvine, Irvine, CA 92697-4120, USA
| | - Suzi Klaus
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA 92697-4025, USA; Institute for Immunology, University of California, Irvine, Irvine, CA 92697-4120, USA
| | - Judith Behnsen
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA 92697-4025, USA; Institute for Immunology, University of California, Irvine, Irvine, CA 92697-4120, USA
| | - Janet Z Liu
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA 92697-4025, USA; Institute for Immunology, University of California, Irvine, Irvine, CA 92697-4120, USA
| | - Nicholas Chim
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697-3900, USA
| | - Sean-Paul Nuccio
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA 92697-4025, USA; Institute for Immunology, University of California, Irvine, Irvine, CA 92697-4120, USA
| | - Subodh G Rathi
- Department of Biochemistry and Chemistry, Vanderbilt University, Nashville, TN 37232-8725, USA
| | - Jennifer R Mastroianni
- Department of Pathology and Laboratory Medicine, University of Southern California, Los Angeles, CA 90089-9092, USA
| | - Robert A Edwards
- Department of Pathology and Laboratory Medicine, University of California, Irvine, Irvine, CA 92697-4800, USA
| | - Christina M Jacobo
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA 92697-4025, USA; Institute for Immunology, University of California, Irvine, Irvine, CA 92697-4120, USA
| | - Mauro Cerasi
- Department of Biology, University of Rome, Tor Vergata, 00173 Roma, Italy
| | - Andrea Battistoni
- Department of Biology, University of Rome, Tor Vergata, 00173 Roma, Italy
| | - André J Ouellette
- Department of Pathology and Laboratory Medicine, University of Southern California, Los Angeles, CA 90089-9092, USA
| | - Celia W Goulding
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697-3900, USA; Department of Pharmaceutical Sciences, University of California, Irvine, Irvine, CA 92697-3958, USA
| | - Walter J Chazin
- Department of Biochemistry and Chemistry, Vanderbilt University, Nashville, TN 37232-8725, USA
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA; Tennessee Valley Healthcare System, US Department of Veterans Affairs, Nashville, TN 37212, USA
| | - Manuela Raffatellu
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA 92697-4025, USA; Institute for Immunology, University of California, Irvine, Irvine, CA 92697-4120, USA.
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11
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Nevins AM, Subramanian A, Tapia JL, Delgado DP, Tyler RC, Jensen DR, Ouellette AJ, Volkman BF. A Requirement for Metamorphic Interconversion in the Antimicrobial Activity of Chemokine XCL1. Biochemistry 2016; 55:3784-93. [PMID: 27305837 DOI: 10.1021/acs.biochem.6b00353] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Chemokines make up a superfamily of ∼50 small secreted proteins (8-12 kDa) involved in a host of physiological processes and disease states, with several previously shown to have direct antimicrobial activity comparable to that of defensins in efficacy. XCL1 is a unique metamorphic protein that interconverts between the canonical chemokine fold and a novel all-β-sheet dimer. Phylogenetic analysis suggests that, within the chemokine family, XCL1 is most closely related to CCL20, which exhibits antibacterial activity. The in vitro antimicrobial activity of WT-XCL1 and structural variants was quantified using a radial diffusion assay (RDA) and in solution bactericidal assays against Gram-positive and Gram-negative species of bacteria. Comparisons of WT-XCL1 with variants that limit metamorphic interconversion showed a loss of antimicrobial activity when restricted to the conserved chemokine fold. These results suggest that metamorphic folding of XCL1 is required for potent antimicrobial activity.
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Affiliation(s)
- Amanda M Nevins
- Department of Biochemistry, Medical College of Wisconsin , Milwaukee, Wisconsin 53226, United States
| | - Akshay Subramanian
- Department of Pathology and Laboratory Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California , Los Angeles, California 90089, United States
| | - Jazma L Tapia
- Department of Pathology and Laboratory Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California , Los Angeles, California 90089, United States
| | - David P Delgado
- Department of Pathology and Laboratory Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California , Los Angeles, California 90089, United States
| | - Robert C Tyler
- Department of Biochemistry, Medical College of Wisconsin , Milwaukee, Wisconsin 53226, United States
| | - Davin R Jensen
- Department of Biochemistry, Medical College of Wisconsin , Milwaukee, Wisconsin 53226, United States
| | - André J Ouellette
- Department of Pathology and Laboratory Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California , Los Angeles, California 90089, United States
| | - Brian F Volkman
- Department of Biochemistry, Medical College of Wisconsin , Milwaukee, Wisconsin 53226, United States
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12
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Wilmes M, Stockem M, Bierbaum G, Schlag M, Götz F, Tran DQ, Schaal JB, Ouellette AJ, Selsted ME, Sahl HG. Killing of staphylococci by θ-defensins involves membrane impairment and activation of autolytic enzymes. Antibiotics (Basel) 2016; 3:617-31. [PMID: 25632351 PMCID: PMC4306331 DOI: 10.3390/antibiotics3040617] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
θ-Defensins are cyclic antimicrobial peptides expressed in leukocytes of Old world monkeys. To get insight into their antibacterial mode of action, we studied the activity of RTDs (rhesus macaque θ-defensins) against staphylococci. We found that in contrast to other defensins, RTDs do not interfere with peptidoglycan biosynthesis, but rather induce bacterial lysis in staphylococci by interaction with the bacterial membrane and/or release of cell wall lytic enzymes. Potassium efflux experiments and membrane potential measurements revealed that the membrane impairment by RTDs strongly depends on the energization of the membrane. In addition, RTD treatment caused the release of Atl-derived cell wall lytic enzymes probably by interaction with membrane-bound lipoteichoic acid. Thus, the premature and uncontrolled activity of these enzymes contributes strongly to the overall killing by θ-defensins. Interestingly, a similar mode of action has been described for Pep5, an antimicrobial peptide of bacterial origin.
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Affiliation(s)
- Miriam Wilmes
- Institute of Medical Microbiology, Immunology and Parasitology, University of Bonn, 53105 Bonn, Germany; E-Mails: (M.S.); (G.B.); (H.-G.S.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +49-228-28711397
| | - Marina Stockem
- Institute of Medical Microbiology, Immunology and Parasitology, University of Bonn, 53105 Bonn, Germany; E-Mails: (M.S.); (G.B.); (H.-G.S.)
| | - Gabriele Bierbaum
- Institute of Medical Microbiology, Immunology and Parasitology, University of Bonn, 53105 Bonn, Germany; E-Mails: (M.S.); (G.B.); (H.-G.S.)
| | - Martin Schlag
- Interfaculty Institute of Microbiology and Infection Medicine, Microbial Genetics, University of Tübingen, 72076 Tübingen, Germany; E-Mails: (M.S.); (F.G.)
| | - Friedrich Götz
- Interfaculty Institute of Microbiology and Infection Medicine, Microbial Genetics, University of Tübingen, 72076 Tübingen, Germany; E-Mails: (M.S.); (F.G.)
| | - Dat Q. Tran
- Department of Pathology and Laboratory Medicine, USC Norris Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089-9601, USA; E-Mails: (D.Q.T.); (J.B.S.); (A.J.O.); (M.E.S.)
| | - Justin B. Schaal
- Department of Pathology and Laboratory Medicine, USC Norris Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089-9601, USA; E-Mails: (D.Q.T.); (J.B.S.); (A.J.O.); (M.E.S.)
| | - André J. Ouellette
- Department of Pathology and Laboratory Medicine, USC Norris Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089-9601, USA; E-Mails: (D.Q.T.); (J.B.S.); (A.J.O.); (M.E.S.)
| | - Michael E. Selsted
- Department of Pathology and Laboratory Medicine, USC Norris Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089-9601, USA; E-Mails: (D.Q.T.); (J.B.S.); (A.J.O.); (M.E.S.)
| | - Hans-Georg Sahl
- Institute of Medical Microbiology, Immunology and Parasitology, University of Bonn, 53105 Bonn, Germany; E-Mails: (M.S.); (G.B.); (H.-G.S.)
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13
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Gounder AP, Myers ND, Treuting PM, Bromme BA, Wilson SS, Wiens ME, Lu W, Ouellette AJ, Spindler KR, Parks WC, Smith JG. Defensins Potentiate a Neutralizing Antibody Response to Enteric Viral Infection. PLoS Pathog 2016; 12:e1005474. [PMID: 26933888 PMCID: PMC4774934 DOI: 10.1371/journal.ppat.1005474] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 02/05/2016] [Indexed: 12/18/2022] Open
Abstract
α-defensins are abundant antimicrobial peptides with broad, potent antibacterial, antifungal, and antiviral activities in vitro. Although their contribution to host defense against bacteria in vivo has been demonstrated, comparable studies of their antiviral activity in vivo are lacking. Using a mouse model deficient in activated α-defensins in the small intestine, we show that Paneth cell α-defensins protect mice from oral infection by a pathogenic virus, mouse adenovirus 1 (MAdV-1). Survival differences between mouse genotypes are lost upon parenteral MAdV-1 infection, strongly implicating a role for intestinal defenses in attenuating pathogenesis. Although differences in α-defensin expression impact the composition of the ileal commensal bacterial population, depletion studies using broad-spectrum antibiotics revealed no effect of the microbiota on α-defensin-dependent viral pathogenesis. Moreover, despite the sensitivity of MAdV-1 infection to α-defensin neutralization in cell culture, we observed no barrier effect due to Paneth cell α-defensin activation on the kinetics and magnitude of MAdV-1 dissemination to the brain. Rather, a protective neutralizing antibody response was delayed in the absence of α-defensins. This effect was specific to oral viral infection, because antibody responses to parenteral or mucosal ovalbumin exposure were not affected by α-defensin deficiency. Thus, α-defensins play an important role as adjuvants in antiviral immunity in vivo that is distinct from their direct antiviral activity observed in cell culture.
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Affiliation(s)
- Anshu P. Gounder
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Nicolle D. Myers
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Piper M. Treuting
- Department of Comparative Medicine, University of Washington, Seattle, Washington, United States of America
| | - Beth A. Bromme
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Sarah S. Wilson
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Mayim E. Wiens
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Wuyuan Lu
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - André J. Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine of the University of Southern California, USC Norris Cancer Center, Los Angeles, California, United States of America
| | - Katherine R. Spindler
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - William C. Parks
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Jason G. Smith
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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14
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Tongaonkar P, Trinh KK, Schaal JB, Tran D, Gulko PS, Ouellette AJ, Selsted ME. Rhesus macaque θ-defensin RTD-1 inhibits proinflammatory cytokine secretion and gene expression by inhibiting the activation of NF-κB and MAPK pathways. J Leukoc Biol 2015; 98:1061-70. [PMID: 26269197 PMCID: PMC4661038 DOI: 10.1189/jlb.3a0315-102r] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 07/12/2015] [Indexed: 01/13/2023] Open
Abstract
The anti‐inflammatory effects of θ‐defensin RTD‐1 are mediated by cell signaling pathways that down‐regulate expression of pro‐inflammatory cytokines. θ‐Defensins are pleiotropic, macrocyclic peptides that are expressed uniquely in Old World monkeys. The peptides are potent, broad‐spectrum microbicides that also modulate inflammatory responses in vitro and in animal models of viral infection and polymicrobial sepsis. θ‐Defensins suppress proinflammatory cytokine secretion by leukocytes stimulated with diverse Toll‐like receptor (TLR) ligands. Studies were performed to delineate anti‐inflammatory mechanisms of rhesus θ‐defensin 1 (RTD‐1), the most abundant θ‐defensin isoform in macaque granulocytes. RTD‐1 reduced the secretion of tumor necrosis factor‐α (TNF‐α), interleukin (IL)‐1β, and IL‐8 in lipopolysaccharide (LPS)‐stimulated human blood monocytes and THP‐1 macrophages, and this was accompanied by inhibition of nuclear factor κB (NF‐κB) activation and mitogen‐activated protein kinase (MAPK) pathways. Peptide inhibition of NF‐κB activation occurred following stimulation of extracellular (TLRs 1/2 and 4) and intracellular (TLR9) receptors. Although RTD‐1 did not inhibit MAPK in unstimulated cells, it induced phosphorylation of Akt in otherwise untreated monocytes and THP‐1 cells. In the latter, this occurred within 10 min of RTD‐1 treatment and produced a sustained elevation of phosphorylated Akt (pAkt) for at least 4 h. pAkt is a negative regulator of MAPK and NF‐κB activation. RTD‐1 inhibited IκBα degradation and p38 MAPK phosphorylation, and stimulated Akt phosphorylation in LPS‐treated human primary monocytes and THP‐1 macrophages. Specific inhibition of phosphatidylinositol 3‐kinase (PI3K) blocked RTD‐1‐stimulated Akt phosphorylation and reversed the suppression of NF‐κB activation by the peptide. These studies indicate that the anti‐inflammatory properties of θ‐defensins are mediated by activation of the PI3K/Akt pathway and suppression of proinflammatory signals in immune‐stimulated cells.
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Affiliation(s)
- Prasad Tongaonkar
- *Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA; and Division of Rheumatology, Department of Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Katie K Trinh
- *Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA; and Division of Rheumatology, Department of Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Justin B Schaal
- *Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA; and Division of Rheumatology, Department of Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Dat Tran
- *Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA; and Division of Rheumatology, Department of Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Percio S Gulko
- *Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA; and Division of Rheumatology, Department of Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - André J Ouellette
- *Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA; and Division of Rheumatology, Department of Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Michael E Selsted
- *Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA; and Division of Rheumatology, Department of Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
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15
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Abadie V, Abraham C, Adams DH, Agace WW, Alexander-Brett J, Alkhairy O, Ambite I, Anderson DJ, Artis D, Atmar RL, Aymeric L, Bachert C, Bakema JE, Baker K, Beagley KW, Befus A, Bemark M, Berin MC, Berings M, Berzofsky JA, Bilej M, Biswas N, Blumberg RS, Bienenstock J, Bogdanos D, Boirivant M, Boonnak K, Bracke KR, Brandtzaeg P, Braun J, Bringer MA, Broadbent AJ, Bronson R, Brusselle GG, Bulmer JN, Butler J, Cardenas PA, Cebra JJ, Cella M, Cerutti A, Challacombe SJ, Chattha K, Cheroutre H, Chiba T, Chorny A, Clements JD, Colonna M, Cookson WO, Corbeil LB, Corthésy B, Cripps AW, van Crombruggen K, Pires da Cunha A, Cunningham-Rundles S, Curtiss R, Darfeuille-Michaud A, de Jonge WJ, Deban L, Denning TL, Di Santo JP, Diefenbach A, DiRita VJ, Downey J, Du MQ, Edelblum KL, van Egmond M, Epple HJ, Fagarasan S, Fahey JV, Ferris MJ, Fichtner-Feigl S, Fidel PL, Flach M, Flavell R, Fleit HB, Franchini G, Freytag LC, Fuchs A, Fujihashi K, Fuss IJ, Gagliani N, Garcia MR, Garrett WS, Gershwin ME, Gevaert P, Gleeson M, Godaly G, Goldblum RM, Gour N, Gursel M, Hajishengallis G, Hammad H, Hammarström L, Hänninen A, Hanson LÅ, Hayday A, Herzog R, Hodgins DC, Holgate ST, Holmgren J, Holtzman MJ, Hook EW, Huber S, Hurwitz JL, Ivanyi J, Iwasaki A, Jabri B, Jackson S, Jacobs J, Jalkanen S, Janoff EN, Jerse AE, Jeyanathan M, Julian BA, Kacskovics I, Kaetzel CS, Kaushic C, Kelsall BL, Kessans S, Kesselring R, Kilian M, Kiyono H, Klinman DM, Korotkova M, Kronenberg M, Krysko O, Kurono Y, Kverka M, Lambrecht BN, Lamm ME, Lantz O, Lash GE, Lavelle E, Lefrancois L, Leung PS, Levine MM, Lim DJ, Lippolis J, Louis NA, Luster AD, Lutay N, Lycke N, Macpherson AJ, Mantis NJ, Marcotte H, Martin DH, Mason HS, Massa HM, Matoba N, Mayer L, Maynard CL, McElrath MJ, McEntee C, McGhee JR, McGuckin MA, Mestecky J, Mikhak Z, Miller RD, Moldoveanu Z, Montgomery PC, Mor T, Neurath MF, Neyt K, Nicholson LK, Novak J, Nowicki S, O’Hagan D, O’Sullivan NL, Ogra P, Orihuela C, Ouellette AJ, Owen RL, Pabst O, Parkos CA, Parreño V, Patel MV, Perez-Novo C, Perkins DJ, Prussin C, Pudney J, Raghavan S, Rainard P, Ramani S, Randall TD, Raska M, Renukaradhya GJ, Rescigno M, Rosenthal KL, Rothenberg ME, Ruemmele FM, Russell MW, Saif LJ, Salinas I, Salmi M, Salmon H, Sampson HA, Sansonetti P, Schneider T, Serafini N, Sharma D, Shen Z, Shi HN, Shirlaw PJ, Shivhare SB, Smith PD, Smith PM, Smith DJ, Smythies LE, Spencer J, Strober W, Subbarao K, Svanborg C, Svennerholm AM, Taubman MA, Telemo E, Thornhill MH, Thornton DJ, Thuenemann E, Tlaskalova-Hogenova H, Tristram D, Trivedi P, Tuomanen E, Turanek J, Turner JR, Underdown BJ, van Helden MJ, Veazey RS, Verdu EF, Vlasova A, Vliagoftis H, Vogel SN, Walker WA, Wang X, Watanabe T, Weaver CT, Weiner HL, Wells JM, Wen T, Whittum-Hudson J, Whitsett JA, Williams IR, Wills-Karp M, Wira CR, Woof JM, Wotherspoon AC, Xing Z, Xu H, Zaph C, Zeissig S, Zeitz M. Contributors. Mucosal Immunol 2015. [DOI: 10.1016/b978-0-12-415847-4.01002-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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17
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Abstract
Small intestinal Paneth cells secrete α-defensin peptides, termed cryptdins (Crps) in mice, into the intestinal lumen, where they confer immunity to oral infections and define the composition of the ileal microbiota. In these studies, facultative bacteria maintained under aerobic or anaerobic conditions displayed differential sensitivities to mouse α-defensins under in vitro assay conditions. Regardless of oxygenation, Crps 2 and 3 had robust and similar bactericidal activities against S. typhimurium and S. flexneri, but Crp4 activity against S. flexneri was attenuated in the absence of oxygen. Anaerobic bacteria varied in their susceptibility to Crps 2-4, with Crp4 showing less activity than Crps 2 and 3 against Enterococcus faecalis, and Bacteroides fragilis in anaerobic assays, but Fusobacterium necrophorum was killed only by Crp4 and not by Crps 2 and 3. The influence of anaerobiosis in modulating Crp bactericidal activities in vitro suggests that α-defensin effects on the enteric microbiota may be subject to regulation by local oxygen tension.
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Affiliation(s)
- Jennifer R. Mastroianni
- Department of Pathology and Laboratory Medicine, Keck School of Medicine of the University of Southern California, USC Norris Cancer Center, Los Angeles, CA 90089-9601, USA; E-Mails: (J.R.M.); (M.E.S.)
| | - Wuyuan Lu
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Institute of Human Virology, Baltimore, MD 21201, USA; E-Mail:
| | - Michael E. Selsted
- Department of Pathology and Laboratory Medicine, Keck School of Medicine of the University of Southern California, USC Norris Cancer Center, Los Angeles, CA 90089-9601, USA; E-Mails: (J.R.M.); (M.E.S.)
| | - André J. Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine of the University of Southern California, USC Norris Cancer Center, Los Angeles, CA 90089-9601, USA; E-Mails: (J.R.M.); (M.E.S.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-323-442-7959
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18
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Tai KP, Kamdar K, Yamaki J, Le VV, Tran D, Tran P, Selsted ME, Ouellette AJ, Wong-Beringer A. Microbicidal effects of α- and θ-defensins against antibiotic-resistant Staphylococcus aureus and Pseudomonas aeruginosa. Innate Immun 2013; 21:17-29. [PMID: 24345876 DOI: 10.1177/1753425913514784] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Antibiotic-resistant bacterial pathogens threaten public health. Because many antibiotics target specific bacterial enzymes or reactions, corresponding genes may mutate under selection and lead to antibiotic resistance. Accordingly, antimicrobials that selectively target overall microbial cell integrity may offer alternative approaches to therapeutic design. Naturally occurring mammalian α- and θ-defensins are potent, non-toxic microbicides that may be useful for treating infections by antibiotic-resistant pathogens because certain defensin peptides disrupt bacterial, but not mammalian, cell membranes. To test this concept, clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA), including vancomycin heteroresistant strains, and ciprofloxacin-resistant Pseudomonas aeruginosa (Cip(R)-PA) were tested for sensitivity to α-defensins Crp-4, RMAD-4 and HNPs 1-3, and to RTD-1, macaque θ-defensin-1. In vitro, 3 μM Crp-4, RMAD-4 and RTD-1 reduced MRSA cell survival by 99%, regardless of vancomycin susceptibility. For PA clinical isolates that differ in fluoroquinolone resistance and virulence phenotype, peptide efficacy was independent of strain ciprofloxacin resistance, site of isolation or virulence factor expression. Thus, Crp-4, RMAD-4 and RTD-1 are effective in vitro antimicrobials against clinical isolates of MRSA and Cip(R)-PA, perhaps providing templates for development of α- and θ-defensin-based microbicides against antibiotic resistant or virulent infectious agents.
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Affiliation(s)
- Kenneth P Tai
- Department of Pathology and Laboratory Medicine, USC Norris Cancer Center, Keck School of Medicine, Los Angeles, CA, USA
| | - Karishma Kamdar
- Department of Pathology and Laboratory Medicine, USC Norris Cancer Center, Keck School of Medicine, Los Angeles, CA, USA
| | - Jason Yamaki
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
| | - Valerie V Le
- Department of Pathology and Laboratory Medicine, USC Norris Cancer Center, Keck School of Medicine, Los Angeles, CA, USA
| | - Dat Tran
- Department of Pathology and Laboratory Medicine, USC Norris Cancer Center, Keck School of Medicine, Los Angeles, CA, USA
| | - Patti Tran
- Department of Pathology and Laboratory Medicine, USC Norris Cancer Center, Keck School of Medicine, Los Angeles, CA, USA
| | - Michael E Selsted
- Department of Pathology and Laboratory Medicine, USC Norris Cancer Center, Keck School of Medicine, Los Angeles, CA, USA
| | - André J Ouellette
- Department of Pathology and Laboratory Medicine, USC Norris Cancer Center, Keck School of Medicine, Los Angeles, CA, USA
| | - Annie Wong-Beringer
- Titus Family Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
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19
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Schaal JB, Tran D, Tran P, Ösapay G, Trinh K, Roberts KD, Brasky KM, Tongaonkar P, Ouellette AJ, Selsted ME. Rhesus macaque theta defensins suppress inflammatory cytokines and enhance survival in mouse models of bacteremic sepsis. PLoS One 2012; 7:e51337. [PMID: 23236475 PMCID: PMC3516535 DOI: 10.1371/journal.pone.0051337] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 11/07/2012] [Indexed: 02/08/2023] Open
Abstract
Theta-defensins (θ-defensins) are macrocyclic antimicrobial peptides expressed in leukocytes of Old World monkeys. The peptides are broad spectrum microbicides in vitro and numerous θ-defensin isoforms have been identified in granulocytes of rhesus macaques and Olive baboons. Several mammalian α- and β-defensins, genetically related to θ-defensins, have proinflammatory and immune-activating properties that bridge innate and acquired immunity. In the current study we analyzed the immunoregulatory properties of rhesus θ-defensins 1–5 (RTDs 1–5). RTD-1, the most abundant θ-defensin in macaques, reduced the levels of TNF, IL-1α, IL-1β, IL-6, and IL-8 secreted by blood leukocytes stimulated by several TLR agonists. RTDs 1–5 suppressed levels of soluble TNF released by bacteria- or LPS-stimulated blood leukocytes and THP-1 monocytes. Despite their highly conserved conformation and amino acid sequences, the anti-TNF activities of RTDs 1–5 varied by as much as 10-fold. Systemically administered RTD-1 was non-toxic for BALB/c mice, and escalating intravenous doses were well tolerated and non-immunogenic in adult chimpanzees. The peptide was highly stable in serum and plasma. Single dose administration of RTD-1 at 5 mg/kg significantly improved survival of BALB/c mice with E. coli peritonitis and cecal ligation-and-puncture induced polymicrobial sepsis. Peptide treatment reduced serum levels of several inflammatory cytokines/chemokines in bacteremic animals. Collectively, these results indicate that the anti-inflammatory properties of θ-defensins in vitro and in vivo are mediated by the suppression of numerous proinflammatory cytokines and blockade of TNF release may be a primary effect.
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Affiliation(s)
- Justin B. Schaal
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Dat Tran
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Patti Tran
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - George Ösapay
- Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, California, United States of America
| | - Katie Trinh
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Kevin D. Roberts
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Kathleen M. Brasky
- Texas Biomedical Research Institute, San Antonio, Texas, United States of America
| | - Prasad Tongaonkar
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - André J. Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Kenneth Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, United States of America
| | - Michael E. Selsted
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Kenneth Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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20
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Park SW, Kim M, Kim JY, Ham A, Brown KM, Mori-Akiyama Y, Ouellette AJ, D'Agati VD, Lee HT. Paneth cell-mediated multiorgan dysfunction after acute kidney injury. J Immunol 2012; 189:5421-33. [PMID: 23109723 DOI: 10.4049/jimmunol.1200581] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Acute kidney injury (AKI) is frequently complicated by extrarenal multiorgan injury, including intestinal and hepatic dysfunction. In this study, we hypothesized that a discrete intestinal source of proinflammatory mediators drives multiorgan injury in response to AKI. After induction of AKI in mice by renal ischemia-reperfusion or bilateral nephrectomy, small intestinal Paneth cells increased the synthesis and release of IL-17A in conjunction with severe intestinal apoptosis and inflammation. We also detected significantly increased IL-17A in portal and systemic circulation after AKI. Intestinal macrophages appear to transport released Paneth cell granule constituents induced by AKI, away from the base of the crypts into the liver. Genetic or pharmacologic depletion of Paneth cells decreased small intestinal IL-17A secretion and plasma IL-17A levels significantly and attenuated intestinal, hepatic, and renal injury after AKI. Similarly, portal delivery of IL-17A in macrophage-depleted mice decreased markedly. In addition, intestinal, hepatic, and renal injury following AKI was attenuated without affecting intestinal IL-17A generation. In conclusion, AKI induces IL-17A synthesis and secretion by Paneth cells to initiate intestinal and hepatic injury by hepatic and systemic delivery of IL-17A by macrophages. Modulation of Paneth cell dysregulation may have therapeutic implications by reducing systemic complications arising from AKI.
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Affiliation(s)
- Sang Won Park
- Department of Anesthesiology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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21
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Affiliation(s)
- André J Ouellette
- Department of Pathology and Laboratory Medicine, USC Norris Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089-9601, USA.
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22
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Burkhardt AM, Tai KP, Flores-Guiterrez JP, Vilches-Cisneros N, Kamdar K, Barbosa-Quintana O, Valle-Rios R, Hevezi PA, Zuñiga J, Selman M, Ouellette AJ, Zlotnik A. CXCL17 is a mucosal chemokine elevated in idiopathic pulmonary fibrosis that exhibits broad antimicrobial activity. J Immunol 2012; 188:6399-406. [PMID: 22611239 DOI: 10.4049/jimmunol.1102903] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The mucosal immune network is a crucial barrier preventing pathogens from entering the body. The network of immune cells that mediates the defensive mechanisms in the mucosa is likely shaped by chemokines, which attract a wide range of immune cells to specific sites of the body. Chemokines have been divided into homeostatic or inflammatory depending upon their expression patterns. Additionally, several chemokines mediate direct killing of invading pathogens, as exemplified by CCL28, a mucosa-associated chemokine that exhibits antimicrobial activity against a range of pathogens. CXCL17 was the last chemokine ligand to be described and is the 17th member of the CXC chemokine family. Its expression pattern in 105 human tissues and cells indicates that CXCL17 is a homeostatic, mucosa-associated chemokine. Its strategic expression in mucosal tissues suggests that it is involved in innate immunity and/or sterility of the mucosa. To test the latter hypothesis, we tested CXCL17 for possible antibacterial activity against a panel of pathogenic and opportunistic bacteria. Our results indicate that CXCL17 has potent antimicrobial activities and that its mechanism of antimicrobial action involves peptide-mediated bacterial membrane disruption. Because CXCL17 is strongly expressed in bronchi, we measured it in bronchoalveolar lavage fluids and observed that it is strongly upregulated in idiopathic pulmonary fibrosis. We conclude that CXCL17 is an antimicrobial mucosal chemokine that may play a role in the pathogenesis of interstitial lung diseases.
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Affiliation(s)
- Amanda M Burkhardt
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA
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23
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Schmidt NW, Tai KP, Kamdar K, Mishra A, Lai GH, Zhao K, Ouellette AJ, Wong GCL. Arginine in α-defensins: differential effects on bactericidal activity correspond to geometry of membrane curvature generation and peptide-lipid phase behavior. J Biol Chem 2012; 287:21866-72. [PMID: 22566697 DOI: 10.1074/jbc.m112.358721] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The conserved tridisulfide array of the α-defensin family imposes a common triple-stranded β-sheet topology on peptides that may have highly diverse primary structures, resulting in differential outcomes after targeted mutagenesis. In mouse cryptdin-4 (Crp4) and rhesus myeloid α-defensin-4 (RMAD4), complete substitutions of Arg with Lys affect bactericidal peptide activity very differently. Lys-for-Arg mutagenesis attenuates Crp4, but RMAD4 activity remains mostly unchanged. Here, we show that the differential biological effect of Lys-for-Arg replacements can be understood by the distinct phase behavior of the experimental peptide-lipid system. In Crp4, small-angle x-ray scattering analyses showed that Arg-to-Lys replacements shifted the induced nanoporous phases to a different range of lipid compositions compared with the Arg-rich native peptide, consistent with the attenuation of bactericidal activity by Lys-for-Arg mutations. In contrast, such phases generated by RMAD4 were largely unchanged. The concordance between small-angle x-ray scattering measurements and biological activity provides evidence that specific types of α-defensin-induced membrane curvature-generating tendencies correspond directly to bactericidal activity via membrane destabilization.
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Affiliation(s)
- Nathan W Schmidt
- Department of Bioengineering, UCLA, Los Angeles, California 90095-1600, USA
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24
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Mastroianni JR, Costales JK, Zaksheske J, Selsted ME, Salzman NH, Ouellette AJ. Alternative luminal activation mechanisms for paneth cell α-defensins. J Biol Chem 2012; 287:11205-12. [PMID: 22334698 DOI: 10.1074/jbc.m111.333559] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Paneth cell α-defensins mediate host defense and homeostasis at the intestinal mucosal surface. In mice, matrix metalloproteinase-7 (MMP7) converts inactive pro-α-defensins (proCrps) to bactericidal forms by proteolysis at specific proregion cleavage sites. MMP7(-/-) mice lack mature α-defensins in Paneth cells, accumulating unprocessed precursors for secretion. To test for activation of secreted pro-α-defensins by host and microbial proteinases in the absence of MMP7, we characterized colonic luminal α-defensins. Protein extracts of complete (organ plus luminal contents) ileum, cecum, and colon of MMP7-null and wild-type mice were analyzed by sequential gel permeation chromatography/acid-urea polyacrylamide gel analyses. Mature α-defensins were identified by N-terminal sequencing and mass spectrometry and characterized in bactericidal assays. Abundance of specific bacterial groups was measured by qPCR using group specific 16 S rDNA primers. Intact, native α-defensins, N-terminally truncated α-defensins, and α-defensin variants with novel N termini due to alternative processing were identified in MMP7(-/-) cecum and colon, and proteinases of host and microbial origin catalyzed proCrp4 activation in vitro. Although Paneth cell α-defensin deficiency is associated with ileal microbiota alterations, the cecal and colonic microbiota of MMP7(-/-) and wild-type mice were not significantly different. Thus, despite the absence of MMP7, mature α-defensins are abundant in MMP7(-/-) cecum and colon due to luminal proteolytic activation by alternative host and microbial proteinases. MMP7(-/-) mice only lack processed α-defensins in the small intestine, and the model is not appropriate for studying effects of α-defensin deficiency in cecal or colonic infection or disease.
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Affiliation(s)
- Jennifer R Mastroianni
- Department of Pathology & Laboratory Medicine and the USC Norris Cancer Center Keck School of Medicine of The University of Southern California, Los Angeles, California 90089-9601, USA
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25
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Schmidt NW, Mishra A, Lai GH, Davis M, Sanders LK, Tran D, Garcia A, Tai KP, McCray PB, Ouellette AJ, Selsted ME, Wong GCL. Criterion for amino acid composition of defensins and antimicrobial peptides based on geometry of membrane destabilization. J Am Chem Soc 2011; 133:6720-7. [PMID: 21473577 DOI: 10.1021/ja200079a] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Defensins comprise a potent class of membrane disruptive antimicrobial peptides (AMPs) with well-characterized broad spectrum and selective microbicidal effects. By using high-resolution synchrotron small-angle X-ray scattering to investigate interactions between heterogeneous membranes and members of the defensin subfamilies, α-defensins (Crp-4), β-defensins (HBD-2, HBD-3), and θ-defensins (RTD-1, BTD-7), we show how these peptides all permeabilize model bacterial membranes but not model eukaryotic membranes: defensins selectively generate saddle-splay ("negative Gaussian") membrane curvature in model membranes rich in negative curvature lipids such as those with phosphoethanolamine (PE) headgroups. These results are shown to be consistent with vesicle leakage assays. A mechanism of action based on saddle-splay membrane curvature generation is broadly enabling, because it is a necessary condition for processes such as pore formation, blebbing, budding, and vesicularization, all of which destabilize the barrier function of cell membranes. Importantly, saddle-splay membrane curvature generation places constraints on the amino acid composition of membrane disruptive peptides. For example, we show that the requirement for generating saddle-splay curvature implies that a decrease in arginine content in an AMP can be offset by an increase in both lysine and hydrophobic content. This "design rule" is consistent with the amino acid compositions of 1080 known cationic AMPs.
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Affiliation(s)
- Nathan W Schmidt
- Department of Physics, University of Illinois, Urbana-Champaign, Illinois 61801, USA
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26
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Shanahan MT, Tanabe H, Ouellette AJ. Strain-specific polymorphisms in Paneth cell α-defensins of C57BL/6 mice and evidence of vestigial myeloid α-defensin pseudogenes. Infect Immun 2011; 79:459-73. [PMID: 21041494 PMCID: PMC3019906 DOI: 10.1128/iai.00996-10] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 10/12/2010] [Accepted: 10/17/2010] [Indexed: 12/18/2022] Open
Abstract
Paneth cells at the base of small intestinal crypts secrete microbicidal α-defensins, termed cryptdins (Crps) in mice, as mediators of innate immunity. Proteomic studies show that five abundant Paneth cell α-defensins in C57BL/6 mice are strain specific in that they have not been identified in other inbred strains of mice. Two C57BL/6-specific peptides are coded for by the Defcr20 and -21 genes evident in the NIH C57BL/6 genome but absent from the Celera mixed-strain assembly, which excludes C57BL/6 data and differs from the NIH build with respect to the organization of the α-defensin gene locus. Conversely, C57BL/6 mice lack the Crp1, -2, -4, and -6 peptides and their corresponding Defcr1, -2, -4, and -6 genes, which are common to several mouse strains, including those of the Celera assembly. In C57BL/6 mice, α-defensin gene diversification appears to have occurred by tandem duplication of a multigene cassette that was not found in the mixed-strain assembly. Both mouse genome assemblies contain conserved α-defensin pseudogenes that are closely related to functional myeloid α-defensin genes in the rat, suggesting that the neutrophil α-defensin defect in mice resulted from progressive gene loss. Given the role of α-defensins in shaping the composition of the enteric microflora, such polymorphisms may influence outcomes in mouse models of disease or infection.
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Affiliation(s)
- Michael T. Shanahan
- Department of Pathology and Laboratory Medicine, Keck School of Medicine of the University of Southern California, Los Angeles, California
| | - Hiroki Tanabe
- Department of Pathology and Laboratory Medicine, Keck School of Medicine of the University of Southern California, Los Angeles, California
| | - André J. Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine of the University of Southern California, Los Angeles, California
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27
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Mishra A, Tai KP, Schmidt NW, Ouellette AJ, Wong GC. Small-Angle X-ray Scattering Studies of Peptide–Lipid Interactions Using the Mouse Paneth Cell α-Defensin Cryptdin-4. Methods Enzymol 2011; 492:127-49. [DOI: 10.1016/b978-0-12-381268-1.00016-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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28
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Zaragoza MM, Sankaran-Walters S, Canfield DR, Hung JKS, Martinez E, Ouellette AJ, Dandekar S. Persistence of gut mucosal innate immune defenses by enteric α-defensin expression in the simian immunodeficiency virus model of AIDS. J Immunol 2010; 186:1589-97. [PMID: 21178012 DOI: 10.4049/jimmunol.1002021] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Gastrointestinal mucosa is an early target of HIV and a site of viral replication and severe CD4(+) T cell depletion. However, effects of HIV infection on gut mucosal innate immune defense have not been fully investigated. Intestinal Paneth cell-derived α-defensins constitute an integral part of the gut mucosal innate defense against microbial pathogens. Using the SIV-infected rhesus macaque model of AIDS, we examined the level of expression of rhesus enteric α-defensins (REDs) in the jejunal mucosa of rhesus macaques during all stages of SIV infection using real-time PCR, in situ hybridization, and immunohistochemistry. An increased expression of RED mRNAs was found in PC at the base of the crypts in jejunum at all stages of SIV infection as compared with uninfected controls. This increase correlated with active viral replication in gut-associated lymphoid tissue. Loss of RED protein accumulation in PC was seen in animals with simian AIDS. This was associated with the loss of secretory granules in PC, suggesting an increase in degranulation during advanced SIV disease. The α-defensin-mediated innate mucosal immunity was maintained in PC throughout the course of SIV infection despite the mucosal CD4(+) T cell depletion. The loss of RED protein accumulation and secretion was associated with an increased incidence of opportunistic enteric infections and disease progression. Our findings suggest that local innate immune defense exerted by PC-derived defensins contributes to the protection of gut mucosa from opportunistic infections during the course of SIV infection.
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Affiliation(s)
- Melinda M Zaragoza
- Department of Medical Microbiology and Immunology, University of California, Davis, Davis, CA 95616, USA
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29
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Tongaonkar P, Tran P, Roberts K, Schaal J, Osapay G, Tran D, Ouellette AJ, Selsted ME. Rhesus macaque θ-defensin isoforms: expression, antimicrobial activities, and demonstration of a prominent role in neutrophil granule microbicidal activities. J Leukoc Biol 2010; 89:283-90. [PMID: 21084627 DOI: 10.1189/jlb.0910535] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Mammalian defensins are cationic, antimicrobial peptides that play a central role in innate immunity. The peptides are composed of three structural subfamilies: α-, β-, and θ-defensins. θ-defensins are macrocyclic octadecapeptides expressed only in Old World monkeys and orangutans and are produced by the pair-wise, head-to-tail splicing of nonapeptides derived from their respective precursors. The existence of three active θ-defensin genes predicts that six different RTDs (1-6) are produced in this species. In this study, we isolated and quantified RTDs 1-6 from the neutrophils of 10 rhesus monkeys. RTD-1 was the most abundant θ-defensin, constituting ~50% of the RTD content; total RTD content varied by as much as threefold between animals. All peptides tested were microbicidal at ∼1 μM concentrations. The contribution of θ-defensins to macaque neutrophil antimicrobial activity was assessed by analyzing the microbicidal properties of neutrophil granule extracts after neutralizing θ-defensin content with a specific antibody. θ-defensin neutralization markedly reduced microbicidal activities of the corresponding extracts. Macaque neutrophil granule extracts had significantly greater microbicidal activity than those of human neutrophils, which lack θ-defensins. Supplementation of human granule extracts with RTD-1 markedly increased the microbicidal activity of these preparations, further demonstrating a prominent microbicidal role for θ-defensins.
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Affiliation(s)
- Prasad Tongaonkar
- Department of Pathology & Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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30
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Abstract
PURPOSE OF REVIEW Recent evidence shows that disruption of Paneth cell homeostasis by induction of endoplasmic reticulum stress or autophagy, with consequent apoptosis, contributes to inflammation and morbidity in a variety of experimental mouse models. RECENT FINDINGS Recent advances show that proinflammatory mediators in Paneth cell dense core secretory granules mediate tumor necrosis factor-α-induced shock, that Paneth cell α-defensins modulate the composition of the small intestinal microflora, that development of crypt organoid culture systems provides a novel means for investigating the crypt microenvironment, and that varied genetic defects that disrupt Paneth cell homeostasis are emergent as risk factors in inflammatory bowel disease. SUMMARY This recent literature identifies Paneth cells as particularly sensitive targets of endoplasmic reticulum stress responses and implicates this unique small intestinal lineage in inflammatory bowel disease pathogenesis resulting from diverse heritable and environmental causes.
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Affiliation(s)
- André J Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine of The University of Southern California, Los Angeles, California 90089-9601, USA.
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31
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Shanahan MT, Vidrich A, Shirafuji Y, Dubois CL, Henschen-Edman A, Hagen SJ, Cohn SM, Ouellette AJ. Elevated expression of Paneth cell CRS4C in ileitis-prone SAMP1/YitFc mice: regional distribution, subcellular localization, and mechanism of action. J Biol Chem 2010; 285:7493-504. [PMID: 20056603 DOI: 10.1074/jbc.m109.083220] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Paneth cells at the base of small intestinal crypts of Lieberkühn secrete host defense peptides and proteins, including alpha-defensins, as mediators of innate immunity. Mouse Paneth cells also express alpha-defensin-related Defcr-rs genes that code for cysteine-rich sequence 4C (CRS4C) peptides that have a unique CPX triplet repeat motif. In ileitis-prone SAMP1/YitFc mice, Paneth cell levels of CRS4C mRNAs and peptides are induced more than a 1000-fold relative to non-prone strains as early as 4 weeks of age, with the mRNA and peptide levels highest in distal ileum and below detection in duodenum. CRS4C-1 peptides are found exclusively in Paneth cells where they occur only in dense core granules and thus are secreted to function in the intestinal lumen. CRS4C bactericidal peptide activity is membrane-disruptive in that it permeabilizes Escherichia coli and induces rapid microbial cell K(+) efflux, but in a manner different from mouse alpha-defensin cryptdin-4. In in vitro studies, inactive pro-CRS4C-1 is converted to bactericidal CRS4C-1 peptide by matrix metalloproteinase-7 (MMP-7) proteolysis of the precursor proregion at the same residue positions that MMP-7 activates mouse pro-alpha-defensins. The absence of processed CRS4C in protein extracts of MMP-7-null mouse ileum demonstrates the in vivo requirement for intracellular MMP-7 in pro-CRS4C processing.
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Affiliation(s)
- Michael T Shanahan
- Department of Microbiology and Molecular Genetics, School of Medicine, College of Health Sciences, University of California, Irvine, California 92697-4800, USA
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Figueredo S, Mastroianni JR, Tai KP, Ouellette AJ. Expression and purification of recombinant alpha-defensins and alpha-defensin precursors in Escherichia coli. Methods Mol Biol 2010; 618:47-60. [PMID: 20094857 DOI: 10.1007/978-1-60761-594-1_4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Recombinant expression of alpha-defensins can be obtained at efficient levels in Escherichia coli. Amplified alpha-defensin or pro-alpha-defensin coding cDNA sequences are cloned directionally between EcoRI and SalI sites of the pET-28a expression vector and expressed in E. coli BL21 RIS cells. Cells growing exponentially in nutrient-rich liquid medium are induced to express the recombinant protein by addition of 50 mM isopropyl beta-D-1-thiogalactopyranoside for 3-6 h. After bacterial cells collected by centrifugation are lysed in 6 M guanidine-HCl under non-reducing conditions, the expressed defensin fused to its 6xHis-34 amino acid N-terminal fusion partner is purified by affinity chromatography on nickel-NTA columns. A Met codon introduced at the N terminus of expressed Met-free peptides provides a unique CNBr cleavage site, enabling release of the alpha-defensin free of ancillary residues by sequential C18 RP-HPLC. Molecular masses of C18 RP-HPLC purified peptides are confirmed by MALDI-TOF mass spectrometry, and peptide homogeneity is assessed using analytical RP-HPLC and acid-urea polyacrylamide gel electrophoresis. alpha-Defensins prepared in this manner are biochemically equivalent to the natural molecules.
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Affiliation(s)
- Sharel Figueredo
- Department of Pathology and Laboratory Medicine, School of Medicine, College of Health Sciences, University of California, Irvine, CA, USA
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Figueredo SM, Ouellette AJ. Inhibition of bactericidal activity is maintained in a mouse alpha-defensin precursor with proregion truncations. Peptides 2010; 31:9-15. [PMID: 19837119 PMCID: PMC2814988 DOI: 10.1016/j.peptides.2009.10.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 10/06/2009] [Accepted: 10/07/2009] [Indexed: 01/06/2023]
Abstract
alpha-Defensin biosynthesis requires the proteolytic conversion of inactive precursors to microbicidal forms. In mouse Paneth cell pro-alpha-defensin proCrp4((20-92)), anionic amino acids positioned near the proregion N-terminus inhibit proCrp4 activity by an apparent charge neutralization mechanism. Because most pro-alpha-defensins contain proregions of highly conserved chain length, we tested whether decreasing the distance between the inhibitory acidic residues of the proregion and the alpha-defensin component of the precursor would alter proCrp4 inhibition. Accordingly, two proCrp4 deletion variants, (Delta44-53)-proCrp4 and (Delta44-58)-proCrp4, truncated in a manner corresponding to deletions between MMP-7 cleavage sites, were prepared and assayed for bactericidal peptide activity. Consistent with the properties of full-length proCrp4((20-92)), (Delta44-53)-proCrp4 and (Delta44-58)-proCrp4 were processed effectively by MMP-7, lacked bactericidal activity at high peptide levels over a 3h exposure period, and failed to induce permeabilization of live Escherichia coliin vitro. Thus, bringing the inhibitory proregion domain into greater proximity with the Crp4 component of the precursor did not alter the activity of this pro-alpha-defensin. Therefore, the conserved distance that separates inhibitory acidic proregion residues from the Crp4 peptide is not critical to maintaining proCrp4((20-92)) in an inactive state.
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Affiliation(s)
- Sharel M. Figueredo
- Department of Pathology & Laboratory Medicine, School of Medicine, College of Health Sciences, University of California, Irvine, CA 92697-4800
| | - André J. Ouellette
- Department of Microbiology & Molecular Genetics, School of Medicine, College of Health Sciences, University of California, Irvine, CA 92697-4800
- Corresponding author: André J. Ouellette, Ph.D., Department of Pathology & Laboratory Medicine, Keck School of Medicine of the University of Southern California, USC Norris Cancer Center, 1450 Biggy Street, NRT 7514 Mail Code 9601, Los Angeles, CA 90033, Tel.: 323-442-7959; Fax: 323-442-7962,
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Zhao F, Edwards R, Dizon D, Afrasiabi K, Mastroianni JR, Geyfman M, Ouellette AJ, Andersen B, Lipkin SM. Disruption of Paneth and goblet cell homeostasis and increased endoplasmic reticulum stress in Agr2-/- mice. Dev Biol 2009; 338:270-9. [PMID: 20025862 DOI: 10.1016/j.ydbio.2009.12.008] [Citation(s) in RCA: 168] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 12/04/2009] [Accepted: 12/08/2009] [Indexed: 12/25/2022]
Abstract
Anterior Gradient 2 (AGR2) is a protein disulfide isomerase that plays important roles in diverse processes in multiple cell lineages as a developmental regulator, survival factor and susceptibility gene for inflammatory bowel disease. Here, we show using germline and inducible Agr2-/- mice that Agr2 plays important roles in intestinal homeostasis. Agr2-/- intestine has decreased goblet cell Mucin 2, dramatic expansion of the Paneth cell compartment, abnormal Paneth cell localization, elevated endoplasmic reticulum (ER) stress, severe terminal ileitis and colitis. Cell culture experiments show that Agr2 expression is induced by ER stress, and that siRNA knockdown of Agr2 increases ER stress response. These studies implicate Agr2 in intestinal homeostasis and ER stress and suggest a role in the etiology of inflammatory bowel disease.
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Affiliation(s)
- Fang Zhao
- Department of Medicine and Biological Chemistry, University of California, Irvine, CA, USA
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Mastroianni JR, Ouellette AJ. Alpha-defensins in enteric innate immunity: functional Paneth cell alpha-defensins in mouse colonic lumen. J Biol Chem 2009; 284:27848-27856. [PMID: 19687006 DOI: 10.1074/jbc.m109.050773] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Paneth cells are a secretory epithelial lineage that release dense core granules rich in host defense peptides and proteins from the base of small intestinal crypts. Enteric alpha-defensins, termed cryptdins (Crps) in mice, are highly abundant in Paneth cell secretions and inherently resistant to proteolysis. Accordingly, we tested the hypothesis that enteric alpha-defensins of Paneth cell origin persist in a functional state in the mouse large bowel lumen. To test this idea, putative Crps purified from mouse distal colonic lumen were characterized biochemically and assayed in vitro for bactericidal peptide activities. The peptides comigrated with cryptdin control peptides in acid-urea-PAGE and SDS-PAGE, providing identification as putative Crps. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry experiments showed that the molecular masses of the putative alpha-defensins matched those of the six most abundant known Crps, as well as N-terminally truncated forms of each, and that the peptides contain six Cys residues, consistent with identities as alpha-defensins. N-terminal sequencing definitively revealed peptides with N termini corresponding to full-length, (des-Leu)-truncated, and (des-Leu-Arg)-truncated N termini of Crps 1-4 and 6. Crps from mouse large bowel lumen were bactericidal in the low micromolar range. Thus, Paneth cell alpha-defensins secreted into the small intestinal lumen persist as intact and functional forms throughout the intestinal tract, suggesting that the peptides may mediate enteric innate immunity in the colonic lumen, far from their upstream point of secretion in small intestinal crypts.
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Affiliation(s)
- Jennifer R Mastroianni
- Department of Pathology and Laboratory Medicine, University of California, Irvine, California 92697-4800
| | - André J Ouellette
- Department of Pathology and Laboratory Medicine, University of California, Irvine, California 92697-4800; Department of Microbiology and Molecular Genetics, University of California, Irvine, California 92697-4800.
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Figueredo SM, Weeks CS, Young SK, Ouellette AJ. Anionic amino acids near the pro-alpha-defensin N terminus mediate inhibition of bactericidal activity in mouse pro-cryptdin-4. J Biol Chem 2008; 284:6826-31. [PMID: 19106102 DOI: 10.1074/jbc.m807024200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In mouse Paneth cells, alpha-defensins, termed cryptdins (Crps), are activated by matrix metalloproteinase-7-mediated proteolysis of inactive precursors (pro-Crps) to bactericidal forms. The activating cleavage step at Ser(43) downward arrow Ile(44) in mouse pro-Crp4-(20-92) removes nine acidic amino acids that collectively block the membrane-disruptive behavior of the Crp4 moiety of the proform. This inhibitory mechanism has been investigated further to identify whether specific cluster(s) of electronegative amino acids in pro-Crp4-(20-43) are responsible for blocking bactericidal activity and membrane disruption. To test whether specific cluster(s) of electronegative amino acids in pro-Crp4-(20-43) have specific positional effects that block bactericidal peptide activity and membrane disruption, acidic residues positioned at the distal (Asp(20), Asp(26), Glu(27), and Glu(28)), mid (Glu(32) and Glu(33)), and proximal (Glu(37), Glu(38), and Asp(39)) clusters in pro-Crp4-(20-92) were mutagenized, and variants were assayed for differential effects of mutagenesis on bactericidal peptide activity. Substitution of the mid and proximal Asp and Glu clusters with Gly produced additive effects with respect to the induction of both bactericidal activity and membrane permeabilization of live Escherichia coli ML35 cells. In contrast, substitution of distal Glu and Asp residues with Gly or their deletion resulted in pro-Crp4-(20-92) variants with bactericidal and membrane-disruptive activities equal to or greater than that of fully mature Crp4. These findings support the conclusion that the most distal N-terminal anionic residues of pro-Crp4-(20-92) are primarily responsible for blocking Crp4-mediated membrane disruption in the precursor.
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Affiliation(s)
- Sharel M Figueredo
- Department of Pathology and Laboratory Medicine, University of California, Irvine, California 92697-4800, USA
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Kamdar K, Maemoto A, Qu X, Young SK, Ouellette AJ. In vitro activation of the rhesus macaque myeloid alpha-defensin precursor proRMAD-4 by neutrophil serine proteinases. J Biol Chem 2008; 283:32361-8. [PMID: 18775986 DOI: 10.1074/jbc.m805296200] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Alpha-defensins are mammalian antimicrobial peptides expressed mainly by cells of myeloid lineage or small intestinal Paneth cells. The peptides are converted from inactive 8.5-kDa precursors to membrane-disruptive forms by post-translational proteolytic events. Because rhesus myeloid pro-alpha-defensin-4 (proRMAD-4((20-94))) lacks bactericidal peptide activity in vitro, we tested whether neutrophil azurophil granule serine proteinases, human neutrophil elastase (NE), cathepsin G (CG), and proteinase-3 (P3) have in vitro convertase activity. Only NE cleaved proRMAD-4((20-94)) at the native RMAD-4 N terminus to produce fully processed, bactericidal RMAD-4((62-94)). The final CG cleavage product was RMAD-4((55-94)), and P3 produced both RMAD-4((55-94)) and RMAD-4(57-94). Nevertheless, NE, CG, and P3 digests of proRMAD4 and purified RMAD-4((62-94)), RMAD-4((55-94)), and RMAD-4(57-94) peptides had equivalent in vitro bactericidal activities. Bactericidal peptide activity assays of proRMAD-4((20-94)) variants containing complete charge-neutralizing D/E to N/Q or D/E to A substitutions showed that (DE/NQ)-proRMAD-4((20-94)) and (DE/A)-proRMAD-4((20-94)) were as active as mature RMAD-4((62-94)). Therefore, proregion Asp and Glu side chains inhibit the RMAD-4 component of full-length proRMAD-4((20-94)), perhaps by a combination of charge-neutralizing and hydrogen-bonding interactions. Although native RMAD-4((62-94)) resists NE, CG, and P3 proteolysis completely, RMAD-4((62-94)) variants with disulfide pairing disruptions or lacking disulfide bonds were degraded extensively, evidence that the disulfide array protects the alpha-defensin moiety from degradation by the myeloid converting enzymes. These in vitro analyses support the conclusion that rhesus macaque myeloid pro-alpha-defensins are converted to active forms by serine proteinases that co-localize in azurophil granules.
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Affiliation(s)
- Karishma Kamdar
- Department of Pathology & Laboratory Medicine, School of Medicine, College of Health Sciences, University of California, Irvine, California 92697-4800, USA
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Abstract
Endogenous antimicrobial peptides (AMPs) mediate innate immunity in every species in which they have been investigated. Cathelicidins and defensins are the two major AMP families in mammals, and they are abundant components of phagocytic leukocytes and are released by epithelial cells at mucosal surfaces. In the small intestine, Paneth cells at the base of the crypts of Lieberkühn secrete alpha-defensins and additional AMPs at high levels in response to cholinergic stimulation and when exposed to bacterial antigens. Paneth cell alpha-defensins evolved to function in the extracellular environment with broad-spectrum antimicrobial activities, and they constitute the majority of bactericidal peptide activity secreted by Paneth cells. The release of Paneth cell products into the crypt lumen is inferred to protect mitotically active crypt cells from colonization by potential pathogens and confers protection from enteric infection, as is evident from the immunity of mice expressing a human Paneth cell alpha-defensin transgene to oral infection by Salmonella enterica serovar Typhimurium. alpha-Defensins in Paneth cell secretions also may interact with bacteria in the intestinal lumen above the crypt-villus boundary and influence the composition of the enteric microbial flora. Mutations that cause defects in the activation, secretion, dissolution, and bactericidal effects of Paneth cell AMPs may alter crypt innate immunity and contribute to immunopathology.
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Affiliation(s)
- A J Ouellette
- Department of Pathology & Laboratory Medicine, School of Medicine, College of Health Sciences, University of California, Irvine 92697-4800, USA.
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Abstract
Antimicrobial proteins stored in lysosome-like granules of neutrophils and macrophages probably play an important role in killing phagocytosed microbes after delivery to the phagolysosome. Among the granules' antimicrobial armamentarium are defensins, peptides that kill a broad spectrum of microorganisms in vitro. Antimicrobial defensins were recently also isolated from non-phagocytic granulocytes of the mouse small intestinal epithelium, from where they are secreted into the lumen to function extracellularly. Clarification of the antimicrobial mechanisms of defensins in intracellular and extracellular environments will provide a key to understanding peptide-mediated host defence.
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Affiliation(s)
- M E Selsted
- Depts of Pathology and Microbiology, College of Medicine, University of California, Irvine, CA 92717, USA
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Lin PW, Simon PO, Gewirtz AT, Neish AS, Ouellette AJ, Madara JL, Lencer WI. 191 PANETH CELL CRYPTDINS ARE APICAL PARACRINE REGULATORS OF THE INNATE INTESTINAL INFLAMMATORY RESPONSE. J Investig Med 2004. [DOI: 10.1136/jim-52-suppl1-744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Kamal M, Wakelin D, Ouellette AJ, Smith A, Podolsky DK, Mahida YR. Mucosal T cells regulate Paneth and intermediate cell numbers in the small intestine of T. spiralis-infected mice. Clin Exp Immunol 2001; 126:117-25. [PMID: 11678907 PMCID: PMC1906161 DOI: 10.1046/j.1365-2249.2001.01589.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2001] [Indexed: 12/24/2022] Open
Abstract
Secretions of Paneth, intermediate and goblet cells have been implicated in innate intestinal host defense. We have investigated the role of T cells in effecting alterations in small intestinal epithelial cell populations induced by infection with the nematode Trichinella spiralis. Small intestinal tissue sections from euthymic and athymic (nude) mice, and mice with combined deficiency in T-cell receptor beta and delta genes [TCR(beta/delta)-/-] infected orally with T. spiralis larvae, were examined by electron microscopy and after histochemical and lineage-specific immunohistochemical staining. Compared with uninfected controls, Paneth and intermediate cell numbers increased significantly in infected euthymic and nude mice but not infected TCR(beta/delta)-/- mice. Transfer of mesenteric lymph node cells before infection led to an increase in Paneth and intermediate cells in TCR(beta/delta)-/- mice. In infected euthymic mice, Paneth cells and intermediate cells expressed cryptdins (alpha-defensins) but not intestinal trefoil factor (ITF), and goblet cells expressed ITF but not cryptdins. In conclusion, a unique, likely thymic-independent population of mucosal T cells modulates innate small intestinal host defense in mice by increasing the number of Paneth and intermediate cells in response to T. spiralis infection.
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Affiliation(s)
- M Kamal
- Division of Gastroenterology, University of NottinghamUK
- School of Biological Sciences, University of NottinghamUK
| | - D Wakelin
- School of Biological Sciences, University of NottinghamUK
| | - A J Ouellette
- Department of Pathology, University of CaliforniaIrvine, USA
| | - A Smith
- Institute of Animal HealthCompton, UK
| | - D K Podolsky
- Gastrointestinal Unit, Massachusetts General Hospital and Harvard Medical SchoolBoston, USA
| | - Y R Mahida
- Division of Gastroenterology, University of NottinghamUK
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Affiliation(s)
- A J Ouellette
- Department of Pathology, College of Medicine, University of California, Irvine 92697-4800, USA.
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Ouellette AJ, Satchell DP, Hsieh MM, Hagen SJ, Selsted ME. Characterization of luminal paneth cell alpha-defensins in mouse small intestine. Attenuated antimicrobial activities of peptides with truncated amino termini. J Biol Chem 2000; 275:33969-73. [PMID: 10942762 DOI: 10.1074/jbc.m004062200] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Paneth cells at the base of small intestinal crypts secrete apical granules that contain antimicrobial peptides including alpha-defensins, termed cryptdins. Using an antibody specific for mouse cryptdin-1, -2, -3, and -6, immunogold-localization studies demonstrated that cryptdins are constituents of mouse Paneth cell secretory granules. Several cryptdin peptides have been purified from rinses of adult mouse small intestine by gel filtration and reverse-phase high performance liquid chromatography. Their primary structures were determined by peptide sequencing, and their antimicrobial activities were compared with those of the corresponding tissue forms. The isolated luminal cryptdins included peptides identical to the tissue forms of cryptdin-2, -4, and -6 as well as variants of cryptdin-1, -4, and -6 that have N termini truncated by one or two residues. In assays of antimicrobial activity against Staphylococcus aureus, Escherichia coli, and the defensin-sensitive Salmonella typhimurium phoP(-) mutant, full-length cryptdins had the same in vitro antibacterial activities whether isolated from tissue or from the lumen. In contrast, the N-terminal-truncated (des-Leu), (des-Leu-Arg)-cryptdin-6, and (des-Gly)-cryptdin-4 peptides were markedly less active. The microbicidal activities of recombinant cryptdin-4 and (des-Gly)-cryptdin-4 peptides against E. coli, and S. typhimurium showed that the N-terminal Gly residue or the length of the cryptdin-4 N terminus are determinants of microbicidal activity. Innate immunity in the crypt lumen may be modulated by aminopeptidase modification of alpha-defensins after peptide secretion.
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Affiliation(s)
- A J Ouellette
- Departments of Pathology and Microbiology and Molecular Genetics, College of Medicine, University of California, Irvine, California 92697-4800, USA.
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Ayabe T, Satchell DP, Wilson CL, Parks WC, Selsted ME, Ouellette AJ. Secretion of microbicidal alpha-defensins by intestinal Paneth cells in response to bacteria. Nat Immunol 2000; 1:113-8. [PMID: 11248802 DOI: 10.1038/77783] [Citation(s) in RCA: 737] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Paneth cells in mouse small intestinal crypts secrete granules rich in microbicidal peptides when exposed to bacteria or bacterial antigens. The dose-dependent secretion occurs within minutes and alpha-defensins, or cryptdins, account for 70% of the released bactericidal peptide activity. Gram-negative bacteria, Gram-positive bacteria, lipopolysaccharide, lipoteichoic acid, lipid A and muramyl dipeptide elicit cryptdin secretion. Live fungi and protozoa, however, do not stimulate degranulation. Thus intestinal Paneth cells contribute to innate immunity by sensing bacteria and bacterial antigens, and discharge microbicidal peptides at effective concentrations accordingly.
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Affiliation(s)
- T Ayabe
- Department of Pathology, College of Medicine, University of California, Irvine, CA 92697, USA
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Abstract
Photosynthetic oxygen evolution is catalyzed at the manganese-containing active site of photosystem II (PSII). Amines are analogs of substrate water and inhibitors of oxygen evolution. Recently, the covalent incorporation of (14)C from [(14)C]methylamine and benzylamine into PSII subunits has been demonstrated (Ouellette, A. J. A., Anderson, L. B., and Barry, B. A. (1998) Proc. Natl. Acad. Sci. U. S. A. 95, 2204-2209). To obtain more information concerning these labeling reactions, t-[(14)C]butylamine and phenylhydrazine were employed as probes. Neither compound can be oxidized by a transamination or addition/elimination mechanism, but both can react with activated carbonyl groups, produced as a result of posttranslational modification of amino acid residues, to give amine-derived adducts. (14)C incorporation into the PSII subunits D2/D1 and CP47 was obtained upon treatment of PSII with either t-[(14)C]butylamine or [(14)C]phenylhydrazine. For t-butylamine and methylamine, the amount of labeling increased when PSII was treated with denaturing agents. Labeling of CP47, D2, and D1 with methylamine and phenylhydrazine approached a one-to-one stoichiometry, assuming that D2 and D1 each have one binding site. Evidence was obtained suggesting that reductive stabilization and/or access are modulated by PSII light reactions. These results support the proposal that PSII subunits D2, D1, and CP47 contain quinocofactors and that access to these sites is sterically limited.
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Affiliation(s)
- L B Anderson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, St. Paul, Minnesota 55108, USA
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Ouellette AJ, Darmoul D, Tran D, Huttner KM, Yuan J, Selsted ME. Peptide localization and gene structure of cryptdin 4, a differentially expressed mouse paneth cell alpha-defensin. Infect Immun 1999; 67:6643-51. [PMID: 10569786 PMCID: PMC97078 DOI: 10.1128/iai.67.12.6643-6651.1999] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/1999] [Accepted: 09/17/1999] [Indexed: 11/20/2022] Open
Abstract
Paneth cells in crypts of the small intestine express antimicrobial peptides, including alpha-defensins, termed cryptdins in mice. Of the known Paneth cell alpha-defensins, the cryptdin 4 gene is unique, because it is inactive in the duodenum and expressed at maximal levels in the distal small bowel (D. Darmoul and A. J. Ouellette, Am. J. Physiol. 271:G68-G74, 1996). With a cryptdin 4-specific antibody, immunohistochemical staining of ileal Paneth cells was strong and specific for cytoplasmic granules, demonstrating that this microbicidal peptide is a secretory product of Paneth cells in the distal small intestine. Consistent with the pattern of cryptdin 4 mRNA distribution along the length of the gut, the cryptdin 4 peptide was not detected in duodenum. Structurally, the cryptdin 4 gene resembles other Paneth cell alpha-defensin genes. Its two exons, transcriptional start site, intron, splice sites, and 3' flanking sequences are characteristic of the highly conserved mouse alpha-defensin genes. However, in the region upstream of the transcriptional initiation site, the cryptdin 4 gene contains a repeated 130-bp element that is unique to this alpha-defensin gene. Every independent cryptdin 4 genomic clone examined carries the repeated element, which contains putative recognition sequences for TF-IID-EIIA, cMyc-RS-1, and IgHC.2/CuE1.1; the repeat proximal to the start of transcription replaces DNA at the corresponding position in other mouse alpha-defensin genes. We speculate that this unique duplicated element may have a cis-acting regulatory role in the positional specificity of cryptdin 4 gene expression.
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Affiliation(s)
- A J Ouellette
- Department of Pathology, College of Medicine, University of California, Irvine, California 92697, USA.
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Tang YQ, Yuan J, Osapay G, Osapay K, Tran D, Miller CJ, Ouellette AJ, Selsted ME. A cyclic antimicrobial peptide produced in primate leukocytes by the ligation of two truncated alpha-defensins. Science 1999; 286:498-502. [PMID: 10521339 DOI: 10.1126/science.286.5439.498] [Citation(s) in RCA: 541] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Analysis of rhesus macaque leukocytes disclosed the presence of an 18-residue macrocyclic, tridisulfide antibiotic peptide in granules of neutrophils and monocytes. The peptide, termed rhesus theta defensin-1 (RTD-1), is microbicidal for bacteria and fungi at low micromolar concentrations. Antibacterial activity of the cyclic peptide was threefold greater than that of an open-chain analog, and the cyclic conformation was required for antimicrobial activity in the presence of 150 millimolar sodium chloride. Biosynthesis of RTD-1 involves the head-to-tail ligation of two alpha-defensin-related nonapeptides, requiring the formation of two new peptide bonds. Thus, host defense cells possess mechanisms for synthesis and granular packaging of macrocyclic antibiotic peptides that are components of the phagocyte antimicrobial armamentarium.
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Affiliation(s)
- Y Q Tang
- Department of Pathology, College of Medicine, University of California, Irvine, CA 92697, USA
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48
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Wilson CL, Ouellette AJ, Satchell DP, Ayabe T, López-Boado YS, Stratman JL, Hultgren SJ, Matrisian LM, Parks WC. Regulation of intestinal alpha-defensin activation by the metalloproteinase matrilysin in innate host defense. Science 1999; 286:113-7. [PMID: 10506557 DOI: 10.1126/science.286.5437.113] [Citation(s) in RCA: 786] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Precursors of alpha-defensin peptides require activation for bactericidal activity. In mouse small intestine, matrilysin colocalized with alpha-defensins (cryptdins) in Paneth cell granules, and in vitro it cleaved the pro segment from cryptdin precursors. Matrilysin-deficient (MAT-/-) mice lacked mature cryptdins and accumulated precursor molecules. Intestinal peptide preparations from MAT-/- mice had decreased antimicrobial activity. Orally administered bacteria survived in greater numbers and were more virulent in MAT-/- mice than in MAT+/+ mice. Thus, matrilysin functions in intestinal mucosal defense by regulating the activity of defensins, which may be a common role for this metalloproteinase in its numerous epithelial sites of expression.
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Affiliation(s)
- C L Wilson
- Department of Pediatrics, Division of Allergy and Pulmonary Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
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Abstract
The hypothesis that epithelial cells release preformed antibiotic peptides as components of mucosal innate immunity has gained experimental support in recent years. In the mammalian small intestine, Paneth cells secrete granules that are rich in alpha-defensins and additional antimicrobial peptides into the lumen of the crypt. The alpha-defensins are homologues of peptides that function as mediators of nonoxidative microbial cell killing in phagocytic leukocytes, and they are potent microbicidal agents in in vitro assays. Because certain mouse alpha-defensins stimulate cultured epithelial cells to secrete chloride ion, those peptides appear to be capable of interacting directly with the apical membranes of neighboring cells and perhaps influencing crypt physiology. In instances of crypt disruption or induced Paneth cell deficiency, crypt intermediate cells appear to compensate by accumulating and secreting Paneth cell antimicrobial peptides. Challenges for the future will be to understand the mechanisms of this epithelial plasticity and to show that Paneth cells contribute directly to innate immunity in the crypt microenvironment.
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Affiliation(s)
- A J Ouellette
- Departments of Pathology and Microbiology and Molecular Genetics, College of Medicine, University of California, Irvine, California 92697-4800, USA.
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50
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