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Johnson-Hence CB, Gopalakrishna KP, Bodkin D, Coffey KE, Burr AH, Rahman S, Rai AT, Abbott DA, Sosa YA, Tometich JT, Das J, Hand TW. Stability and heterogeneity in the antimicrobiota reactivity of human milk-derived immunoglobulin A. J Exp Med 2023; 220:e20220839. [PMID: 37462916 PMCID: PMC10354535 DOI: 10.1084/jem.20220839] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [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: 05/12/2022] [Revised: 04/11/2023] [Accepted: 06/15/2023] [Indexed: 07/21/2023] Open
Abstract
Immunoglobulin A (IgA) is secreted into breast milk and is critical for both protecting against enteric pathogens and shaping the infant intestinal microbiota. The efficacy of breast milk-derived maternal IgA (BrmIgA) is dependent upon its specificity; however, heterogeneity in BrmIgA binding ability to the infant microbiota is not known. Using a flow cytometric array, we analyzed the reactivity of BrmIgA against bacteria common to the infant microbiota and discovered substantial heterogeneity between all donors, independent of preterm or term delivery. Surprisingly, we also observed intradonor variability in the BrmIgA response to closely related bacterial isolates. Conversely, longitudinal analysis showed that the antibacterial BrmIgA reactivity was relatively stable through time, even between sequential infants, indicating that mammary gland IgA responses are durable. Together, our study demonstrates that the antibacterial BrmIgA reactivity displays interindividual heterogeneity but intraindividual stability. These findings have important implications for how breast milk shapes the development of the preterm infant microbiota and protects against necrotizing enterocolitis.
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Affiliation(s)
- Chelseá B. Johnson-Hence
- Pediatrics Department, Infectious Disease Section, R.K. Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Kathyayini P. Gopalakrishna
- Pediatrics Department, Infectious Disease Section, R.K. Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Darren Bodkin
- Pediatrics Department, Infectious Disease Section, R.K. Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kara E. Coffey
- Pediatrics Department, Infectious Disease Section, R.K. Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Pediatrics, Division of Allergy and Immunology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ansen H.P. Burr
- Pediatrics Department, Infectious Disease Section, R.K. Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Immunology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Syed Rahman
- Department of Immunology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Center for Systems Immunology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ali T. Rai
- Pediatrics Department, Infectious Disease Section, R.K. Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Darryl A. Abbott
- Pediatrics Department, Infectious Disease Section, R.K. Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Yelissa A. Sosa
- Pediatrics Department, Infectious Disease Section, R.K. Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Justin T. Tometich
- Pediatrics Department, Infectious Disease Section, R.K. Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jishnu Das
- Department of Immunology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Center for Systems Immunology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Timothy W. Hand
- Pediatrics Department, Infectious Disease Section, R.K. Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Immunology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
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2
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Johnson-Hence CB, Gopalakrishna KP, Bodkin D, Coffey KE, Burr AH, Rahman S, Rai AT, Abbott DA, Sosa YA, Tometich JT, Das J, Hand TW. Stability and heterogeneity in the anti-microbiota reactivity of human milk-derived Immunoglobulin A. bioRxiv 2023:2023.03.16.532940. [PMID: 36993366 PMCID: PMC10055037 DOI: 10.1101/2023.03.16.532940] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
UNLABELLED Immunoglobulin A (IgA) is secreted into breast milk and is critical to both protecting against enteric pathogens and shaping the infant intestinal microbiota. The efficacy of breast milk-derived maternal IgA (BrmIgA) is dependent upon its specificity, however heterogeneity in BrmIgA binding ability to the infant microbiota is not known. Using a flow cytometric array, we analyzed the reactivity of BrmIgA against bacteria common to the infant microbiota and discovered substantial heterogeneity between all donors, independent of preterm or term delivery. We also observed intra-donor variability in the BrmIgA response to closely related bacterial isolates. Conversely, longitudinal analysis showed that the anti-bacterial BrmIgA reactivity was relatively stable through time, even between sequential infants, indicating that mammary gland IgA responses are durable. Together, our study demonstrates that the anti-bacterial BrmIgA reactivity displays inter-individual heterogeneity but intra-individual stability. These findings have important implications for how breast milk shapes the development of the infant microbiota and protects against Necrotizing Enterocolitis. SUMMARY We analyze the ability of breast milk-derived Immunoglobulin A (IgA) antibodies to bind the infant intestinal microbiota. We discover that each mother secretes into their breast milk a distinct set of IgA antibodies that are stably maintained over time.
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Affiliation(s)
- Chelseá B. Johnson-Hence
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh PA, 15224
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, University of Texas Southwestern Medical Center
| | - Kathyayini P. Gopalakrishna
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh PA, 15224
| | - Darren Bodkin
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh PA, 15224
| | - Kara E. Coffey
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh PA, 15224
- Department of Pediatrics, Division of Allergy and Immunology, University of Pittsburgh School of Medicine
| | - Ansen H.P. Burr
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh PA, 15224
- Department of Immunology, University of Pittsburgh School of Medicine
| | - Syed Rahman
- Department of Immunology, University of Pittsburgh School of Medicine
- Center for Systems Immunology, University of Pittsburgh School of Medicine
| | - Ali T. Rai
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh PA, 15224
| | - Darryl A. Abbott
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh PA, 15224
| | - Yelissa A. Sosa
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh PA, 15224
| | - Justin T. Tometich
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh PA, 15224
| | - Jishnu Das
- Department of Immunology, University of Pittsburgh School of Medicine
- Center for Systems Immunology, University of Pittsburgh School of Medicine
| | - Timothy W. Hand
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh PA, 15224
- Department of Immunology, University of Pittsburgh School of Medicine
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3
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Airik M, McCourt B, Ozturk TT, Huynh AB, Zhang X, Tometich JT, Topaloglu R, Ozen H, Orhan D, Nejak-Bowen K, Monga SP, Hand TW, Ozaltin F, Airik R. Mitigation of portal fibrosis and cholestatic liver disease in ANKS6-deficient livers by macrophage depletion. FASEB J 2022; 36:e22157. [PMID: 35032404 PMCID: PMC8852242 DOI: 10.1096/fj.202101387r] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [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: 09/02/2021] [Revised: 12/19/2021] [Accepted: 12/27/2021] [Indexed: 02/03/2023]
Abstract
Congenital hepatic fibrosis (CHF) is a developmental liver disease that is caused by mutations in genes that encode ciliary proteins and is characterized by bile duct dysplasia and portal fibrosis. Recent work has demonstrated that mutations in ANKS6 can cause CHF due to its role in bile duct development. Here, we report a novel ANKS6 mutation, which was identified in an infant presenting with neonatal jaundice due to underlying biliary abnormalities and liver fibrosis. Molecular analysis revealed that ANKS6 liver pathology is associated with the infiltration of inflammatory macrophages to the periportal fibrotic tissue and ductal epithelium. To further investigate the role of macrophages in CHF pathophysiology, we generated a novel liver-specific Anks6 knockout mouse model. The mutant mice develop biliary abnormalities and rapidly progressing periportal fibrosis reminiscent of human CHF. The development of portal fibrosis in Anks6 KO mice coincided with the accumulation of inflammatory monocytes and macrophages in the mutant liver. Gene expression and flow cytometric analysis demonstrated the preponderance of M1- over M2-like macrophages at the onset of fibrosis. A critical role for macrophages in promoting peribiliary fibrosis was demonstrated by depleting the macrophages with clodronate liposomes which effectively reduced inflammatory gene expression and fibrosis, and ameliorated tissue histology and biliary function in Anks6 KO livers. Together, this study demonstrates that macrophages play an important role in the initiation of liver fibrosis in ANKS6-deficient livers and their therapeutic elimination may provide an avenue to mitigate CHF in patients.
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Affiliation(s)
- Merlin Airik
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Blake McCourt
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tugba Tastemel Ozturk
- Division of Pediatric Nephrology, Department of Pediatrics, Hacettepe University, Ankara, Turkey
| | - Amy B Huynh
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Xiaoyi Zhang
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Justin T Tometich
- R.K. Mellon Institute for Pediatric Research, Department of Pediatrics, Division of Infectious Disease, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA, 15224
| | - Rezan Topaloglu
- Division of Pediatric Nephrology, Department of Pediatrics, Hacettepe University, Ankara, Turkey
| | - Hasan Ozen
- Division of Gastroenterology, Department of Pediatrics, Hacettepe University, Ankara, Turkey
| | - Diclehan Orhan
- Pediatric Pathology Unit, Department of Pediatrics, Hacettepe University, Ankara, Turkey
| | - Kari Nejak-Bowen
- Department of Pathology and Pittsburgh Liver Research Center, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Satdarshan P Monga
- Department of Pathology and Pittsburgh Liver Research Center, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Timothy W Hand
- R.K. Mellon Institute for Pediatric Research, Department of Pediatrics, Division of Infectious Disease, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA, 15224
| | - Fatih Ozaltin
- Division of Pediatric Nephrology, Department of Pediatrics, Hacettepe University, Ankara, Turkey,Nephrogenetics Laboratory, Division of Pediatric Nephrology, Department of Pediatrics, Hacettepe University, Ankara, Turkey
| | - Rannar Airik
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA,Department of Developmental Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA,Corresponding Author: Name: Rannar Airik, PhD, Address: UPMC Children’s Hospital of Pittsburgh, 4401 Penn Avenue, Pittsburgh, PA 15224, USA, , Tel.: +1 (412) 692-6229, Fax.: +1 (412) 692-7816
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4
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Bhattacharjee A, Burr AHP, Overacre-Delgoffe AE, Tometich JT, Yang D, Huckestein BR, Linehan JL, Spencer SP, Hall JA, Harrison OJ, Morais da Fonseca D, Norton EB, Belkaid Y, Hand TW. Environmental enteric dysfunction induces regulatory T cells that inhibit local CD4+ T cell responses and impair oral vaccine efficacy. Immunity 2021; 54:1745-1757.e7. [PMID: 34348118 DOI: 10.1016/j.immuni.2021.07.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [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] [Received: 05/18/2020] [Revised: 04/21/2021] [Accepted: 07/09/2021] [Indexed: 12/13/2022]
Abstract
Environmental enteric dysfunction (EED) is a gastrointestinal inflammatory disease caused by malnutrition and chronic infection. EED is associated with stunting in children and reduced efficacy of oral vaccines. To study the mechanisms of oral vaccine failure during EED, we developed a microbiota- and diet-dependent mouse EED model. Analysis of E. coli-labile toxin vaccine-specific CD4+ T cells in these mice revealed impaired CD4+ T cell responses in the small intestine and but not the lymph nodes. EED mice exhibited increased frequencies of small intestine-resident RORγT+FOXP3+ regulatory T (Treg) cells. Targeted deletion of RORγT from Treg cells restored small intestinal vaccine-specific CD4 T cell responses and vaccine-mediated protection upon challenge. However, ablation of RORγT+FOXP3+ Treg cells made mice more susceptible to EED-induced stunting. Our findings provide insight into the poor efficacy of oral vaccines in EED and highlight how RORγT+FOXP3+ Treg cells can regulate intestinal immunity while leaving systemic responses intact.
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Affiliation(s)
- Amrita Bhattacharjee
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA 15224 USA
| | - Ansen H P Burr
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA 15224 USA; Program in Microbiology and Immunology, Department of Immunology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15261, USA
| | - Abigail E Overacre-Delgoffe
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA 15224 USA
| | - Justin T Tometich
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA 15224 USA
| | - Deyi Yang
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA 15224 USA; Central South University, Xiangya School of Medicine, Changsha, PRC
| | - Brydie R Huckestein
- Program in Microbiology and Immunology, Department of Immunology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15261, USA
| | - Jonathan L Linehan
- Metaorganism Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD, USA
| | - Sean P Spencer
- Metaorganism Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD, USA
| | - Jason A Hall
- Metaorganism Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD, USA
| | - Oliver J Harrison
- Metaorganism Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD, USA
| | - Denise Morais da Fonseca
- Metaorganism Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD, USA
| | - Elizabeth B Norton
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Yasmine Belkaid
- Metaorganism Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD, USA
| | - Timothy W Hand
- R.K. Mellon Institute for Pediatric Research, Pediatrics Department, Infectious Disease Section, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA 15224 USA; Program in Microbiology and Immunology, Department of Immunology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15261, USA.
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5
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Narla ST, Bushnell DS, Schaefer CM, Nouraie M, Tometich JT, Hand TW, Bates CM. Loss of Fibroblast Growth Factor Receptor 2 (FGFR2) Leads to Defective Bladder Urothelial Regeneration after Cyclophosphamide Injury. Am J Pathol 2020; 191:631-651. [PMID: 33385344 DOI: 10.1016/j.ajpath.2020.12.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 11/03/2020] [Accepted: 12/10/2020] [Indexed: 10/22/2022]
Abstract
Cyclophosphamide may cause hemorrhagic cystitis and eventually bladder urothelial cancer. Genetic determinants for poor outcomes are unknown. We assessed actions of fibroblast growth factor receptor (FGFR) 2 in urothelium after cyclophosphamide exposure. Conditional urothelial deletion of Fgfr2 (Fgfr2KO) did not affect injury severity or proliferation of keratin 14+ (KRT14+) basal progenitors or other urothelial cells 1 day after cyclophosphamide exposure. Three days after cyclophosphamide exposure, Fgfr2KO urothelium had defective regeneration, fewer cells, larger basal cell bodies and nuclei, paradoxical increases in proliferation markers, and excessive replication stress versus controls. Fgfr2KO mice had evidence of pathologic basal cell endoreplication associated with absent phosphorylated ERK staining and decreased p53 expression versus controls. Mice with conditional deletion of Fgfr2 in urothelium enriched for KRT14+ cells reproduced Fgfr2KO abnormalities after cyclophosphamide exposure. Fgfr2KO urothelium had defects up to 6 months after injury versus controls, including larger basal cells and nuclei, more persistent basal and ectopic lumenal KRT14+ cells, and signs of metaplasia (attenuated E-cadherin staining). Mice missing one allele of Fgfr2 also had (less severe) regeneration defects and basal cell endoreplication 3 days after cyclophosphamide exposure versus controls. Thus, reduced FGFR2/ERK signaling apparently leads to abnormal urothelial repair after cyclophosphamide exposure from pathologic basal cell endoreplication. Patients with genetic variants in FGFR2 or its ligands may have increased risks of hemorrhagic cystitis or urothelial cancer from persistent and ectopic KRT14+ cells.
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Affiliation(s)
- Sridhar T Narla
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Daniel S Bushnell
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Caitlin M Schaefer
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Mehdi Nouraie
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Justin T Tometich
- Mellon Institute for Pediatric Research, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Infectious Disease Section, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania
| | - Timothy W Hand
- Mellon Institute for Pediatric Research, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Infectious Disease Section, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania
| | - Carlton M Bates
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Division of Nephrology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania.
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Hand TW, Gopalakrishna K, Macadangdang BR, Rogers M, Tometich JT, Ji J, Firek BA, Baker R, Burr AH, Ma C, Good M, Morowitz M. Maternal Immunoglobulin A protects against the development of necrotizing enterocolitis in preterm infants. The Journal of Immunology 2019. [DOI: 10.4049/jimmunol.202.supp.192.10] [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] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Neonates are particularly susceptible to infection by colonizing microbes, and mammals protect their offspring via antibodies secreted into breast milk. Necrotizing Enterocolitis(NEC) is a disease of preterm infants characterized by intestinal epithelial damage and inflammation associated with the microbiota. The incidence of NEC is significantly lower in infants fed with maternal milk, though the mechanisms underlying this protective benefit are not clear. Here, we show that maternal Immunoglobulin A (IgA) is an important factor in protection against NEC. Analysis of IgA-binding within fecal samples from preterm infants indicated that breast milk was the predominant source of IgA in the first month of life and that a relative decrease in the fraction of bacteria bound by IgA is associated with the development of NEC. Sequencing of IgA-bound and unbound bacteria revealed that NEC was associated with increasing domination of the IgA unbound microbiota by Enterobacteriaceae, prior to disease onset. Further, we confirmed that IgA is critical in preventing NEC in a murine model, where we demonstrate that pups reared by IgA deficient mothers are susceptible to disease despite exposure to maternal milk. This study illustrates the importance of maternal IgA in shaping the host-microbiota relationship of preterm neonates and provides evidence that IgA is a critical factor in maternal milk necessary for the prevention of NEC.
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Affiliation(s)
| | | | | | | | | | - Junyi Ji
- 5Department of Basic Medical Sciences, School of Medicine, Tsinghua University
| | | | - Robyn Baker
- 4University of Pittsburgh, Department of Pediatrics
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7
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Lamens KD, Rogers MC, Tometich JT, Hand TW, Williams JV. Uncharted Territory: The CD4+ T cell response to human metapneumovirus. The Journal of Immunology 2019. [DOI: 10.4049/jimmunol.202.supp.198.2] [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] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Human metapneumovirus (HMPV) is a leading cause of lower respiratory tract infection in pediatric and immunocompromised populations. Clearance of respiratory viruses including HMPV relies primarily on the destruction of infected cells by cytotoxic CD8+ T cells. However, signals provided by CD4+ helper T cells significantly impact the magnitude and effectiveness of CD8+ T cells. Using a mouse model of acute infection, we performed an in-depth analysis of CD4+ helper T cells in the immune response to HMPV. We identified and validated an immunodominant CD4+ T cell epitope in C57BL/6 mice and constructed the first MHC-II tetramer for HMPV. Kinetic analysis showed that the percentage of CD44+tetramer+ cells in the lung peaked at day 10 post-infection. Ex vivo peptide stimulation of pulmonary T cells revealed that most virus-specific CD4+ T cells produced IFNγ, followed by a small but consistent population of IL-17a producing cells. To determine the contribution of CD4+ T cells in the primary immune response to HMPV, CD4+ T cells were antibody-depleted prior to infection. Depletion of CD4+ T cells exacerbated infection-induced CD8+ T cell impairment, led to enhanced PD-1 expression on virus-specific CD8+ T cells, and delayed viral clearance. Next, global PD-1−/− mice were infected with HMPV to further explore the role of PD-1. Both CD4+ and CD8+ T cells displayed improved functionality in HMPV-infected PD-1−/− mice, suggesting that PD-1-mediated impairment following respiratory virus infection affects CD4+ as well as CD8+ T cells. Further characterization of virus-specific CD4+ helper T cells, their regulation by PD-1, and their role in CD8+ T cell impairment will provide new insights that aid in the design of effective vaccines against HMPV.
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Affiliation(s)
- Kristina D Lamens
- 1University of Pittsburgh School of Medicine
- 2University of Pittsburgh, Department of Pediatrics
| | | | - Justin T Tometich
- 1University of Pittsburgh School of Medicine
- 2University of Pittsburgh, Department of Pediatrics
| | - Timothy W Hand
- 1University of Pittsburgh School of Medicine
- 2University of Pittsburgh, Department of Pediatrics
| | - John V Williams
- 1University of Pittsburgh School of Medicine
- 2University of Pittsburgh, Department of Pediatrics
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8
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Chiaranunt P, Tometich JT, Ji J, Hand TW. T Cell Proliferation and Colitis Are Initiated by Defined Intestinal Microbes. J Immunol 2018; 201:243-250. [PMID: 29777027 DOI: 10.4049/jimmunol.1800236] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 04/23/2018] [Indexed: 12/22/2022]
Abstract
Inflammatory bowel disease has been associated with the dysregulation of T cells specific to Ags derived from the intestinal microbiota. How microbiota-specific T cells are regulated is not completely clear but is believed to be mediated by a combination of IgA, regulatory T cells, and type 3 innate lymphoid cells. To test the role of these regulatory components on microbiota-specific T cells, we bred CBir1 TCR transgenic (CBir1Tg) mice (specific to flagellin from common intestinal bacteria) onto a lymphopenic Rag1-/- background. Surprisingly, T cells from CBir1Tg mice bred onto a Rag1-/- background could not induce colitis and did not differentiate to become effectors under lymphopenic conditions, despite deficits in immunoregulatory factors, such as IgA, regulatory T cells, and type 3 innate lymphoid cells. In fact, upon transfer of conventional CBir1Tg T cells into lymphopenic mice, the vast majority of proliferating T cells responded to Ags other than CBir1 flagellin, including those found on other bacteria, such as Helicobacter spp. Thus, we discovered a caveat in the CBir1Tg model within our animal facility that illustrates the limitations of using TCR transgenics at mucosal surfaces, where multiple TCR specificities can respond to the plethora of foreign Ags. Our findings also indicate that T cell specificity to the microbiota alone is not sufficient to induce T cell activation and colitis. Instead, other interrelated factors, such as the composition and ecology of the intestinal microbiota and host access to Ag, are paramount in controlling the activation of microbiota-specific T cell clones.
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Affiliation(s)
- Pailin Chiaranunt
- Richard King Mellon Foundation Institute for Pediatric Research, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, PA 15224.,Department of Pediatrics, University of Pittsburgh Medical School, Pittsburgh, PA 15224
| | - Justin T Tometich
- Richard King Mellon Foundation Institute for Pediatric Research, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, PA 15224.,Department of Pediatrics, University of Pittsburgh Medical School, Pittsburgh, PA 15224
| | - Junyi Ji
- Richard King Mellon Foundation Institute for Pediatric Research, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, PA 15224.,Department of Pediatrics, University of Pittsburgh Medical School, Pittsburgh, PA 15224.,School of Medicine, Tsinghua University, Beijing 100084, China; and
| | - Timothy W Hand
- Richard King Mellon Foundation Institute for Pediatric Research, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, PA 15224; .,Department of Pediatrics, University of Pittsburgh Medical School, Pittsburgh, PA 15224.,Department of Immunology, University of Pittsburgh Medical School, Pittsburgh, PA 15213
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