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Ng WK, Lim TS, Lai NS. Expression of soluble human Neonatal Fc-receptor (FcRn) in Escherichia coli through modification of growth environment. Protein Expr Purif 2016; 127:73-80. [PMID: 27412717 DOI: 10.1016/j.pep.2016.07.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [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] [Received: 04/29/2016] [Revised: 07/01/2016] [Accepted: 07/08/2016] [Indexed: 11/17/2022]
Abstract
Neonatal Fc-receptor (FcRn) with its affinity to immunoglobulin G (IgG) has been the subject of many pharmacokinetic studies in the past century. This protein is well known for its unique feature in maintaining the circulating IgG from degradation in blood plasma. FcRn is formed by non-covalent association between the α-chain with the β-2-microglobulin (β2m). Many studies have been conducted to produce FcRn in the laboratory, mainly using mammalian tissue culture as host for recombinant protein expression. In this study, we demonstrate a novel strategy to express the α-chain of FcRn using Escherichia coli as the expression host. The expression vector that carries the cDNA of the α-chain was transformed into expression host, Rosetta-gami 2 strain for inducible expression. The bacterial culture was grown in a modified growth medium which constitutes of terrific broth, sodium chloride (NaCl), glucose and betaine. A brief heat shock at 45 °C was carried out after induction, before the temperature for expression was reduced to 22 °C and grown for 16 h. The soluble form of the α-chain of FcRn expressed was tested in the ELISA and dot blot immunoassay to confirm its native functionality. The results implied that the α-chain of FcRn expressed using this method is functional and retains its pH-dependent affinity to IgG. Our study significantly suggests that the activity of human FcRn remain active and functional in the absence of β2m.
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Affiliation(s)
- Woei Kean Ng
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Pulau Pinang, Malaysia
| | - Theam Soon Lim
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Pulau Pinang, Malaysia
| | - Ngit Shin Lai
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Pulau Pinang, Malaysia.
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2
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Lundberg K, Rydnert F, Broos S, Andersson M, Greiff L, Lindstedt M. Allergen-Specific Immunotherapy Alters the Frequency, as well as the FcR and CLR Expression Profiles of Human Dendritic Cell Subsets. PLoS One 2016; 11:e0148838. [PMID: 26863539 PMCID: PMC4749279 DOI: 10.1371/journal.pone.0148838] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 01/25/2016] [Indexed: 11/19/2022] Open
Abstract
Allergen-specific immunotherapy (AIT) induces tolerance and shifts the Th2 response towards a regulatory T-cell profile. The underlying mechanisms are not fully understood, but dendritic cells (DC) play a vital role as key regulators of T-cell responses. DCs interact with allergens via Fc receptors (FcRs) and via certain C-type lectin receptors (CLRs), including CD209/DC-SIGN, CD206/MR and Dectin-2/CLEC6A. In this study, the effect of AIT on the frequencies as well as the FcR and CLR expression profiles of human DC subsets was assessed. PBMC was isolated from peripheral blood from seven allergic donors before and after 8 weeks and 1 year of subcutaneous AIT, as well as from six non-allergic individuals. Cells were stained with antibodies against DC subset-specific markers and a panel of FcRs and CLRs and analyzed by flow cytometry. After 1 year of AIT, the frequency of CD123+ DCs was increased and a larger proportion expressed FcεRI. Furthermore, the expression of CD206 and Dectin-2 was reduced on CD141+ DCs after 1 year of treatment and CD206 as well as Dectin-1 was additionally down regulated in CD1c+ DCs. Interestingly, levels of DNGR1/CLEC9A on CD141+ DCs were increased by AIT, reaching levels similar to cells isolated from non-allergic controls. The modifications in phenotype and occurrence of specific DC subsets observed during AIT suggest an altered capacity of DC subsets to interact with allergens, which can be part of the mechanisms by which AIT induces allergen tolerance.
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Affiliation(s)
- Kristina Lundberg
- Department of Immunotechnology, Lund University, Lund, Sweden
- * E-mail:
| | - Frida Rydnert
- Department of Immunotechnology, Lund University, Lund, Sweden
| | - Sissela Broos
- Department of Immunotechnology, Lund University, Lund, Sweden
| | - Morgan Andersson
- Department of Otorhinolaryngology, Head & Neck Surgery, Skåne University Hospital, Lund, Sweden
| | - Lennart Greiff
- Department of Otorhinolaryngology, Head & Neck Surgery, Skåne University Hospital, Lund, Sweden
| | - Malin Lindstedt
- Department of Immunotechnology, Lund University, Lund, Sweden
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Hornby PJ, Cooper PR, Kliwinski C, Ragwan E, Mabus JR, Harman B, Thompson S, Kauffman AL, Yan Z, Tam SH, Dorai H, Powers GD, Giles-Komar J. Human and non-human primate intestinal FcRn expression and immunoglobulin G transcytosis. Pharm Res 2013; 31:908-22. [PMID: 24072267 PMCID: PMC3953555 DOI: 10.1007/s11095-013-1212-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 09/12/2013] [Indexed: 11/29/2022]
Abstract
Purpose To evaluate transcytosis of immunoglobulin G (IgG) by the neonatal Fc receptor (FcRn) in adult primate intestine to determine whether this is a means for oral delivery of monoclonal antibodies (mAbs). Methods Relative regional expression of FcRn and localization in human intestinal mucosa by RT-PCR, ELISA & immunohistochemistry. Transcytosis of full-length mAbs (sandwich ELISA-based detection) across human intestinal segments mounted in Ussing-type chambers, human intestinal (caco-2) cell monolayers grown in transwells, and serum levels after regional intestinal delivery in isoflurane-anesthetized cynomolgus monkeys. Results In human intestine, there was an increasing proximal-distal gradient of mucosal FcRn mRNA and protein expression. In cynomolgus, serum mAb levels were greater after ileum-proximal colon infusion than after administration to stomach or proximal small intestine (1–5 mg/kg). Serum levels of wild-type mAb dosed into ileum/proximal colon (2 mg/kg) were 124 ± 104 ng/ml (n = 3) compared to 48 ± 48 ng/ml (n = 2) after a non-FcRn binding variant. In vitro, mAb transcytosis in polarized caco-2 cell monolayers and was not enhanced by increased apical cell surface IgG binding to FcRn. An unexpected finding in primate small intestine, was intense FcRn expression in enteroendocrine cells (chromagranin A, GLP-1 and GLP-2 containing). Conclusions In adult primates, FcRn is expressed more highly in distal intestinal epithelial cells. However, mAb delivery to that region results in low serum levels, in part because apical surface FcRn binding does not influence mAb transcytosis. High FcRn expression in enteroendocrine cells could provide a novel means to target mAbs for metabolic diseases after systemic administration.
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Affiliation(s)
- Pamela J Hornby
- Biologics Research, Biotechnology CoE, Janssen Pharmaceutical J&J, Radnor, Pennsylvania, 19087, USA,
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4
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Avrorova IV, Korsakova II, Zhukova SI, Khrapova NP, Dem'ianova OB, Lomova LV, Napalkova GM. [Immunogenic and protective characteristics of surface antigens 6 and d of Burkholderia pseudomallei]. Zh Mikrobiol Epidemiol Immunobiol 2010:40-44. [PMID: 20734717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
AIM Extraction of complex of Burkholderia pseudomallei antigens 6+d (Ag6+d) and study of its immunogenic and protective characteristics. MATERIALS AND METHODS Studied antigens were obtained from acrtone-dried cells of B. pseudomallei 57576. Experiments were performed on white mouse model. Microbiological, immunochemical as well as immunological methods were used in the study. RESULTS It was shown that antigenic complex 6+d has a glycoprotein nature and corresponds to high-polymeric catode-moving antigen 6 with molecular mass 500 kDa and anode-moving antigen d with molecular mass 40 - 55 kDa. Immunogenic and protective characteristics of surface antigenic complex 6+d was studied. It was noted that Ag6+d caused reliable stimulating effect on cellular arm of immune system of white mice appeared in activation of delayed-type hypersensitivity reactions, enhanced phagocytic activity of polymorphonuclear macrophages as well as increased expression of Fc-receptors on macrophages and neutrophils. CONCLUSION Observed stimulation of cellular immunity by surface antigens was confirmed during study of their protective characteristics on the model of experimental meloidosis in white mice.
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Abstract
Here, we show that the platelet-derived growth factor receptor (PDGFR) regulates myeloid and monocytic differentiation of HL-60 myeloblastic leukemia cells in response to retinoic acid (RA) and vitamin D3 (D3), respectively. Both RA and D3 decreased the expression of PDGFR-alpha and PDGFR-beta throughout differentiation. When cells were treated with the PDGFR inhibitor AG1296 in addition to RA or D3, signs of terminal differentiation such as inducible oxidative metabolism and cell substrate adhesion were enhanced. These changes were accompanied by an increased extracellular signal-regulated kinase 1/2 activation. AG1296 also resulted in elevated expression of differentiation markers CD11b and CD66c when administered with RA or D3. Interestingly, other markers did not follow the same pattern. Cells receiving AG1296 in addition to RA or D3 showed decreased G1-G0 arrest and CD14, CD38, and CD89 expression. We thus provide evidence that certain sets of differentiation markers can be enhanced, whereas others can be inhibited by the PDGFR pathway. In addition, we found calcium levels to be decreased by RA and D3 but increased when AG1296 was given in addition to RA or D3, suggesting that calcium levels decrease during myeloid or monocytic differentiation, and elevated calcium levels can disturb the expression of certain differentiation markers.
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Affiliation(s)
- Gudrun Reiterer
- Department of Biomedical Sciences, Cornell University, Ithaca, New York 14853, USA
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6
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Inozume T, Mitsui H, Okamoto T, Matsuzaki Y, Kawakami Y, Shibagaki N, Shimada S. Dendritic cells transduced with autoantigen FCRLA induce cytotoxic lymphocytes and vaccinate against murine B-cell lymphoma. J Invest Dermatol 2007; 127:2818-22. [PMID: 17625599 DOI: 10.1038/sj.jid.5700909] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [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: 11/09/2022]
Abstract
We previously reported early evidence of the human Fc receptor-like A (hFCRLA), an antigen (Ag) that was specifically expressed in melanocytes, melanoma cells, and some B-cell states, and was recognized by IgG antibodies from melanoma patients. Recently, it has been demonstrated that hFCRLA is expressed in most human B-cell lymphoma tissues. In this report, we investigated the potential of FCRLA as a tumor-associated Ag of B-cell lymphoma for immunotherapy. We confirmed that murine FCRLA (mFCRLA) was expressed and distributed in murine tissues similar to hFCRLA. Recombinant mFCRLA fusion protein was constructed with a polyarginine (R9)-protein-transduction domain (PTD) (rR9-HA-mFCRL), and was transduced into bone marrow-derived dendritic cells (DC) ex vivo. Mice immunized with rR9-HA-mFCRL-treated DC primed cytotoxic T-lymphocyte (CTL) that killed the B-cell lymphoma cell line (A20), which express mFCRLA abundantly. In a tumor challenging study, A20 tumor growth inoculated in skin was significantly suppressed in mice vaccinated with rR9-HA-mFCRL-treated DC, compared with control mice. These results indicated that FCRLA is a potential target Ag in immunotherapy for B-cell lymphoma. In addition, our experimental system using R9-PTD-containing full-length proteins might be a useful method to analyze the immunogenicity of novel candidates of tumor-associated Ags in vivo.
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Affiliation(s)
- Takashi Inozume
- Faculty of Medicine, Department of Dermatology, University of Yamanashi, Yamanashi, Japan
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Volkova OY, Reshetnikova ES, Mechetina LV, Chikaev NA, Najakshin AM, Faizulin RZ, Duzhak TG, Taranin AV. Generation and Characterization of Monoclonal Antibodies Specific for Human FCRLA. Hybridoma (Larchmt) 2007; 26:78-85. [PMID: 17451355 DOI: 10.1089/hyb.2006.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [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: 11/13/2022]
Abstract
FCRLA is a recently identified intracellular protein structurally related to the classic Fc receptors and expressed primarily in the germinal centers of B cells. We generated six monoclonal antibodies (MAbs) specific to the human protein. The MAbs recognize three different epitopes, which were shown to be localized on the D3 domain of the FCRLA molecule. The clones M101 and M616 were demonstrated to be applicable in various immunochemical analyses, such as immunoblotting, immunohistochemistry, and immunoprecipitation. In addition, this pair of antibodies was used for development of a sandwich version of ELISA to quantitatively detect FCRLA in cell lysates. Using these MAbs, we studied FCRLA expression in a panel of human B cell lines, such as Raji, Daudi, Bjab, BL-2, RPMI 1788, RPMI 8226, IM-9, and SKW6.4. It was found that all these lines, except RPMI 8226, produce FCRLA but may vary in the proportion of FCRLA-positive cells. The MAbs we established can be a useful tool to investigate the functional role of FCRLA and its applicability as a B cell development and malignant transformation marker.
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Affiliation(s)
- Olga Y Volkova
- Laboratory of Immunogenetics, The Institute of Cytology and Genetics, Russian Academy of Sciences, Novosibirsk, Russia.
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Won WJ, Foote JB, Odom MR, Pan J, Kearney JF, Davis RS. Fc receptor homolog 3 is a novel immunoregulatory marker of marginal zone and B1 B cells. J Immunol 2007; 177:6815-23. [PMID: 17082595 DOI: 10.4049/jimmunol.177.10.6815] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Two members of the recently identified FcR homolog (FcRH) family in mice demonstrate preferential B cell expression. One of these, FcRH3, encodes a type I transmembrane protein with five extracellular Ig domains and a cytoplasmic tail with a consensus ITIM and a noncanonical ITAM. Analysis of full-length cDNAs from five different mouse strains defines two FcRH3 alleles. A panel of FcRH3-specific mAbs was generated to define its expression pattern and functional potential on B lineage cells. Although poorly detected on the majority of bone marrow or peripheral blood cells, FcRH3 was readily identified on splenic marginal zone (MZ) and MZ precursor B cells, but not on the bulk of newly formed B cells, follicular B cells, germinal center B cells, and plasma cells. In the peritoneal cavity, FcRH3 was found on B1 cells, and not on the majority of B2 cells. Consistent with its possession of an ITIM and ITAM-like sequence, FcRH3 was tyrosine phosphorylated following pervanadate treatment, and its coligation with the BCR inhibited calcium mobilization. These results suggest FcRH3 is a novel immunoregulatory marker of MZ and B1 B lineage cells.
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MESH Headings
- Alleles
- Animals
- Antibodies, Monoclonal/metabolism
- B-Lymphocyte Subsets/immunology
- B-Lymphocyte Subsets/metabolism
- Biomarkers/metabolism
- Cells, Cultured
- Female
- Immunoglobulin Allotypes/metabolism
- Immunologic Factors/biosynthesis
- Lymphocyte Activation/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Inbred CBA
- Mice, Inbred NZB
- Mice, Transgenic
- Receptors, Fc/biosynthesis
- Receptors, Fc/genetics
- Receptors, Fc/immunology
- Spleen/cytology
- Spleen/immunology
- Spleen/metabolism
- Stem Cells/immunology
- Stem Cells/metabolism
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Affiliation(s)
- Woong-Jai Won
- Division of Developmental and Clinical Immunology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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9
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Leopold PL, Wendland RL, Vincent T, Crystal RG. Neutralized adenovirus-immune complexes can mediate effective gene transfer via an Fc receptor-dependent infection pathway. J Virol 2006; 80:10237-47. [PMID: 17005701 PMCID: PMC1617312 DOI: 10.1128/jvi.00512-06] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [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: 12/22/2022] Open
Abstract
Neutralization of adenovirus (Ad) by anti-Ad neutralizing antibodies in serum involves formation of Ad-immune complexes that prevent the virus from interacting with target cells. We hypothesized that Ad-immune complexes likely contain viable Ad vectors which, although no longer capable of gaining access to receptors on target cells, may be able to express transgenes in cells bearing Fc receptors for immunoglobulins, i.e., that antibody-based "neutralization" of Ad vectors may be circumvented by the Fc receptor pathway. To test this hypothesis, we expressed the Fcgamma receptor IIA (FcgammaR) in A549 lung epithelial cells or human dermal fibroblasts and evaluated gene transfer in the presence of human neutralizing anti-Ad serum. FcgammaR-expressing cells bound and internalized copious amounts of Ad, with a distinct population of internalized Ad trafficking to the nucleus. The dose-response curves for inhibition of gene transfer revealed that FcgammaR-expressing cells required a more-than-10-fold higher concentration of anti-Ad serum to achieve 50% inhibition of Ad-encoded beta-galactosidase expression compared with non-FcgammaR-expressing cells. The discrepancy between neutralization of Ad during infection of FcgammaR-expressing cells and neutralization of Ad during infection of non-FcgammaR-expressing cells occurred with either heat-inactivated or non-heat-inactivated sera, was blocked by addition of purified Fc domain protein, and did not require the cytoplasmic domain of FcgammaR, suggesting that immune complex internalization proceeded via endocytosis rather than phagocytosis. FcgammaR-mediated infection by Ad-immune complexes did not require expression of the coxsackie virus-Ad receptor (CAR) since similar data were obtained when CAR-deficient human dermal fibroblasts were engineered to express FcgammaR. However, interaction of the Ad penton base with cell surface integrins contributed to the difference in neutralization between FcgammaR-expressing and non-FcgammaR-expressing cells. The data indicate that complexes formed from Ad and anti-Ad neutralizing antibodies, while compromised with respect to infection of non-FcgammaR-expressing target cells, maintain the potential to transfer genes to FcgammaR-expressing cells, with consequent expression of the transgene. The formation of Ad-immune complexes that can target viable virus to antigen-presenting cells may account for the success of Ad-based vaccines administered in the presence of low levels of neutralizing anti-Ad antibody.
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Affiliation(s)
- Philip L Leopold
- Weill Medical College of Cornell University, Department of Genetic Medicine, 1300 York Avenue, W401, New York, NY 10021, USA.
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10
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Hamerman JA, Jarjoura JR, Humphrey MB, Nakamura MC, Seaman WE, Lanier LL. Cutting edge: inhibition of TLR and FcR responses in macrophages by triggering receptor expressed on myeloid cells (TREM)-2 and DAP12. J Immunol 2006; 177:2051-5. [PMID: 16887962 DOI: 10.4049/jimmunol.177.4.2051] [Citation(s) in RCA: 318] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
DAP12 is an ITAM-containing adapter that associates with receptors in myeloid and NK cells. DAP12-associated receptors can give activation signals leading to cytokine production; however, in some situations, DAP12 inhibits cytokine production stimulated through TLRs and FcRs. Here we show that Triggering Receptor Expressed on Myeloid cells (TREM)-2 is responsible for the DAP12-mediated inhibition in mouse macrophages. A chimeric receptor composed of the extracellular domain of TREM-2 and the cytoplasmic domain of DAP12 inhibited the TLR- and FcR-induced TNF production of DAP12-deficient macrophages, whereas a TREM-1 chimera did not. In wild-type macrophages, TREM-2 knockdown increased TLR-induced TNF production. A TREM-2 Fc fusion protein bound to macrophages, indicating that macrophages express a TREM-2 ligand. Thus, the interaction of TREM-2 and its ligand results in an inhibitory signal that can reduce the inflammatory response.
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MESH Headings
- Adaptor Proteins, Signal Transducing/biosynthesis
- Adaptor Proteins, Signal Transducing/deficiency
- Adaptor Proteins, Signal Transducing/genetics
- Animals
- Cells, Cultured
- Inflammation Mediators/antagonists & inhibitors
- Inflammation Mediators/metabolism
- Ligands
- Macrophages/immunology
- Macrophages/metabolism
- Membrane Glycoproteins/biosynthesis
- Membrane Glycoproteins/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Receptors, Fc/antagonists & inhibitors
- Receptors, Fc/biosynthesis
- Receptors, Immunologic/biosynthesis
- Receptors, Immunologic/physiology
- Toll-Like Receptors/antagonists & inhibitors
- Toll-Like Receptors/biosynthesis
- Tumor Necrosis Factor-alpha/biosynthesis
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Affiliation(s)
- Jessica A Hamerman
- Department of Microbiology and Immunology, University of California-San Francisco, 514 Parnassus Avenue, San Francisco, CA 94143, USA
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Stafford JL, Wilson M, Nayak D, Quiniou SM, Clem LW, Miller NW, Bengtén E. Identification and Characterization of a FcR Homolog in an Ectothermic Vertebrate, the Channel Catfish (Ictalurus punctatus). J Immunol 2006; 177:2505-17. [PMID: 16888012 DOI: 10.4049/jimmunol.177.4.2505] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
An FcR homolog (IpFcRI), representing the first such receptor from an ectothermic vertebrate, has been identified in the channel catfish (Ictalurus punctatus). Mining of the catfish expressed sequence tag databases using mammalian FcR sequences for CD16, CD32, and CD64 resulted in the identification of a teleost Ig-binding receptor. IpFcRI is encoded by a single-copy gene containing three Ig C2-like domains, but lacking a transmembrane segment and cytoplasmic tail. The encoded Ig domains of IpFcRI are phylogenetically and structurally related to mammalian FcR and the presence of a putative Fc-binding region appears to be conserved. IpFcRI-related genomic sequences are also present in both pufferfish and rainbow trout, indicating the likely presence of a soluble FcR in other fish species. Northern blot and qualitative PCR analyses demonstrated that IpFcRI is primarily expressed in IgM-negative leukocytes derived from the lymphoid kidney tissues and PBL. Significantly lower levels of IpFcRI expression were detected in catfish clonal leukocyte cell lines. Using the native leader, IpFcRI was secreted when transfected into insect cells and importantly the native IpFcRI glycoprotein was detected in catfish plasma using a polyclonal Ab. Recombinant IpFcRI binds catfish IgM as assessed by both coimmunoprecipation and cell transfection studies and it is presumed that it functions as a secreted FcR akin to the soluble FcR found in mammals. The identification of an FcR homolog in an ectothermic vertebrate is an important first step toward understanding the evolutionary history and functional importance of vertebrate Ig-binding receptors.
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Affiliation(s)
- James L Stafford
- Department of Microbiology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216, USA
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12
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Abstract
Anaplasma phagocytophilum is a tick-transmitted obligate intracellular bacterium of neutrophils that causes human granulocytic anaplasmosis. Previous data confirm that in vitro infection by A. phagocytophilum modifies neutrophil functions, including a 50% or greater reduction in phagocytosis and shedding of neutrophil cell surface adhesion molecule receptors. If these receptors are downregulated or shed from the surface of neutrophils with A. phagocytophilum infection, it may prevent neutrophils from effective phagocytosis. We hypothesized that diminished phagocytosis in neutrophils is partly associated with the loss of surface phagocytic receptors. To address this, we assayed the expression of these receptors after 24 h of A. phagocytophilum infection in human neutrophils.
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Affiliation(s)
- Justin W A Garyu
- Division of Medical Microbiology, Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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13
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Sakagami M, Omidi Y, Campbell L, Kandalaft LE, Morris CJ, Barar J, Gumbleton M. Expression and Transport Functionality of FcRn within Rat Alveolar Epithelium: A Study in Primary Cell Culture and in the Isolated Perfused Lung. Pharm Res 2006; 23:270-9. [PMID: 16382279 DOI: 10.1007/s11095-005-9226-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2005] [Accepted: 10/21/2005] [Indexed: 11/26/2022]
Abstract
PURPOSE The neonatal constant region fragment receptor (FcRn) binds and transports IgG. FcRn expression in the upper tracheobronchial airways of the lung is recognized. In this study, we sought to characterize the functional expression of FcRn within alveolar regions of lung tissue. METHODS FcRn immunohistochemistry was performed on intact rat lung. FcRn expression [Western blot, reverse transcription-polymerase chain reaction (RT-PCR), and immunofluorescence microscopy] and IgG transport functionality were assessed in an in vitro rat alveolar epithelial primary cell culture model. An isolated perfused rat lung model was used to examine IgG transport across pulmonary epithelium from airspace to perfusate. RESULTS FcRn is expressed in intact alveolar epithelium, substantiated by expression and functionality in an in vitro alveolar epithelial model within which IgG transport was temperature sensitive, concentration dependent, and inhibited by excess unlabeled IgG and, to a disproportionate level, by anti-FcRn antibody. Saturable IgG transport across pulmonary epithelium was evident in an isolated perfused rat lung, inhibitable by competing IgG, and displayed a relatively low maximal net IgG absorptive rate of approximately 80 ng/h. CONCLUSION Pulmonary epithelium expresses functional FcRn providing an absorption pathway potentially important for highly potent Fcgamma-fusion proteins but unlikely to be of quantitative significance for the systemic delivery of inhaled therapeutic monoclonal IgGs.
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Affiliation(s)
- Masahiro Sakagami
- Department of Pharmaceutics, School of Pharmacy, Virginia Commonwealth University, Richmond, 23298-0533, USA
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14
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Mukasa R, Terada Y, Shiroishi M, Fujiwara H, Hayata K, Morishita K, Ra C, Takashi T. Rapid receptor-proximal signaling assays for FcR gamma-containing receptors. J Immunol Methods 2005; 303:105-21. [PMID: 16048727 DOI: 10.1016/j.jim.2005.06.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2005] [Revised: 04/25/2005] [Accepted: 06/08/2005] [Indexed: 11/27/2022]
Abstract
Novel, cell-based assays, based on bioluminescence resonance energy transfer, have been developed for FcepsilonRI- and GPVI-FcRgamma complex-mediated signaling at receptor-proximal steps. In a stable transfectant of the HEK-293 cell line expressing human FcepsilonRIalpha, FcepsilonRIbeta, and FcRgamma-GFP2 and Syk(1-265)-Rluc fusion proteins, FcepsilonRI cross-linking markedly increased BRET2 ratios, which are the ratios of GFP2 emission to Rluc emission. These ratios reflect the FcRgamma-GFP2-Syk(1-265)-Rluc interaction in living cells. The signals are specifically inhibited by the Src-family kinase inhibitor PP2. Separately, in transient transfectants expressing GPVI, FcRgamma-GFP2, and Syk(1-265)-Rluc, the GPVI-specific ligand convulxin induced a two-fold increase in the BRET2 ratio and this increase was also inhibited by PP2. Finally, a differential assay was developed which permits the measurement of FcepsilonRI- and GPVI-FcRgamma complex-mediated signaling in the same cell. These assays provide useful methods for monitoring FcRgamma-Syk interaction in real time in living cells and may contribute to the understanding of signal regulation through FcRgamma-containing receptors.
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Affiliation(s)
- Ryuta Mukasa
- New Product Research Laboratories III, Daiichi Pharmaceutical Co., Ltd., 1-16-13 Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan.
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15
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Ehrhardt GRA, Hsu JT, Gartland L, Leu CM, Zhang S, Davis RS, Cooper MD. Expression of the immunoregulatory molecule FcRH4 defines a distinctive tissue-based population of memory B cells. ACTA ACUST UNITED AC 2005; 202:783-91. [PMID: 16157685 PMCID: PMC2212938 DOI: 10.1084/jem.20050879] [Citation(s) in RCA: 248] [Impact Index Per Article: 13.1] [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] [Indexed: 11/12/2022]
Abstract
The FcRH4 transmembrane molecule, a member of the Fc receptor homologue family, can potently inhibit B cell receptor (BCR) signaling. We show that cell surface expression of this immunoregulatory molecule is restricted to a subpopulation of memory B cells, most of which lack the classical CD27 marker for memory B cells in humans. The FcRH4+ and FcRH4− memory B cells have undergone comparable levels of immunoglobulin isotype switching and somatic hypermutation, while neither subpopulation expresses the transcription factors involved in plasma cell differentiation. The FcRH4+ memory cells are morphologically distinctive large lymphocytes that express the CD69, CD80, and CD86 cell activation markers. They are also shown to be poised to secrete high levels of immunoglobulins in response to stimulation with T cell cytokines, but they fail to proliferate in response either to BCR ligation or Staphylococcus aureus stimulation. A heightened expression of the CCR1 and CCR5 chemokine receptors may facilitate their preferential localization in lymphoid tissues near epithelial surfaces. Cell surface FcRH4 expression thus marks a unique population of memory B cells with distinctive morphology, functional capabilities, and tissue localization.
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Affiliation(s)
- Götz R A Ehrhardt
- Division of Clinical and Developmental Immunology, University of Alabama at Birmingham, Birmingham, Birmingham, AL 35294, USA
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16
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Otten MA, Rudolph E, Dechant M, Tuk CW, Reijmers RM, Beelen RHJ, van de Winkel JGJ, van Egmond M. Immature Neutrophils Mediate Tumor Cell Killing via IgA but Not IgG Fc Receptors. J Immunol 2005; 174:5472-80. [PMID: 15843545 DOI: 10.4049/jimmunol.174.9.5472] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Antitumor Abs are promising therapeutics for cancer. Currently, most Ab-based therapies focus on IgG Ab, which interact with IgG FcR (FcgammaR) on effector cells. In this study, we examined human and mouse neutrophil-mediated tumor cell lysis via targeting the IgA FcR, FcalphaRI (CD89), in more detail. FcalphaRI was the most effective FcR in triggering tumor cell killing, and initiated enhanced migration of neutrophils into tumor colonies. Importantly, immature neutrophils that are mobilized from the bone marrow upon G-CSF treatment efficiently triggered tumor cell lysis via FcalphaRI, but proved incapable of initiating tumor cell killing via FcgammaR. This may provide a rationale for the disappointing results observed in some earlier clinical trials in which patients were treated with G-CSF and antitumor Ab-targeting FcgammaR.
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MESH Headings
- Animals
- Antibody-Dependent Cell Cytotoxicity/genetics
- Antibody-Dependent Cell Cytotoxicity/immunology
- Antigens, CD/biosynthesis
- Antigens, CD/blood
- Antigens, CD/genetics
- Antigens, CD/physiology
- Bone Marrow Cells/cytology
- Bone Marrow Cells/immunology
- Bone Marrow Cells/metabolism
- Cell Communication/genetics
- Cell Communication/immunology
- Cell Death/genetics
- Cell Death/immunology
- Cell Differentiation/immunology
- Cell Line, Tumor
- Cytotoxicity Tests, Immunologic/methods
- Granulocyte Colony-Stimulating Factor/pharmacology
- Humans
- Mice
- Mice, Transgenic
- Neutrophil Infiltration/immunology
- Neutrophils/cytology
- Neutrophils/immunology
- Neutrophils/metabolism
- Receptors, Fc/biosynthesis
- Receptors, Fc/blood
- Receptors, Fc/genetics
- Receptors, Fc/physiology
- Receptors, IgG/biosynthesis
- Receptors, IgG/blood
- Receptors, IgG/genetics
- Receptors, IgG/physiology
- Signal Transduction/genetics
- Signal Transduction/immunology
- Video Recording
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Affiliation(s)
- Marielle A Otten
- Immunotherapy Laboratory, Department of Immunology, University Medical Center Utrecht, The Netherlands
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17
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Abstract
Fc receptor homologs are a recently identified family of proteins homologous to FcgammaRI, found on human and mouse B cells. One of these, FREB/FcRX/FCRL, was found to be unique since it lacks a transmembrane domain and is expressed intracellularly within germinal center B cells. We have identified in humans and mice a new Fc receptor homolog, FREB2, that blends conserved elements of the classical Fc gamma receptors with structural motifs previously thought to be unique to FREB1. This protein is comprised of three immunoglobulin-like domains with high homology to those in FcgammaRI, and a C-terminus containing a proline-rich stalk region followed by a leucine-rich amphipathic alpha helix. Like FREB1, FREB2 is expressed as an intracellular protein. In murine splenocytes, RNA transcripts for each of the two proteins can be amplified from germinal center B cells. However, immunohistochemical analysis of human tonsils indicates that expression of FREB1 and FREB2 is mutually exclusive in non-neoplastic cells. Importantly, FREB2 expression within human tonsils appears to be limited to a small subset of nonproliferating germinal center B cells, suggesting that it may play a role in regulating clonal expansion or differentiation of B cells during the germinal center reaction.
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Affiliation(s)
- T J Wilson
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO 63110, USA
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18
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Decot V, Woerly G, Loyens M, Loiseau S, Quatannens B, Capron M, Dombrowicz D. Heterogeneity of expression of IgA receptors by human, mouse, and rat eosinophils. J Immunol 2005; 174:628-35. [PMID: 15634880 DOI: 10.4049/jimmunol.174.2.628] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IgA is the most abundant class of Abs at mucosal surfaces where eosinophils carry out many of their effector functions. Most of the known IgA-mediated functions require interactions with IgA receptors, six of which have been identified in humans. These include the IgA FcR FcalphaRI/CD89 and the receptor for the secretory component, already identified on human eosinophils, the polymeric IgR, the Fcalpha/muR, asialoglycoprotein (ASGP)-R, and transferrin (Tf)R/CD71. In rodents, the existence of IgA receptors on mouse and rat eosinophils remains unclear. We have compared the expression and function of IgA receptors by human, rat, and mouse eosinophils. Our results show that human eosinophils express functional polymeric IgR, ASGP-R, and TfR, in addition to CD89 and the receptor for the secretory component, and that IgA receptors are expressed by rodent eosinophils. Indeed, mouse eosinophils expressed only TfR, whereas rat eosinophils expressed ASGP-R and CD89 mRNA. These results provide a molecular basis for the differences observed between human, rat, and mouse regarding IgA-mediated immunity.
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MESH Headings
- Animals
- Asialoglycoprotein Receptor/biosynthesis
- Asialoglycoprotein Receptor/blood
- Cells, Cultured
- Eosinophils/immunology
- Eosinophils/metabolism
- Humans
- Immunoglobulin A/blood
- Mice
- Mice, Inbred BALB C
- Mice, Transgenic
- Protein Binding/immunology
- Rats
- Rats, Inbred BN
- Receptors, Fc/biosynthesis
- Receptors, Fc/blood
- Receptors, Polymeric Immunoglobulin/biosynthesis
- Receptors, Polymeric Immunoglobulin/blood
- Receptors, Transferrin/biosynthesis
- Receptors, Transferrin/blood
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Affiliation(s)
- Véronique Decot
- Institut National de la Santé et de la Recherche Médicale Unité 547-Institut Fédératif de Recherche 17, Institut Pasteur de Lille, France
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19
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Berntzen G, Lunde E, Flobakk M, Andersen JT, Lauvrak V, Sandlie I. Prolonged and increased expression of soluble Fc receptors, IgG and a TCR-Ig fusion protein by transiently transfected adherent 293E cells. J Immunol Methods 2005; 298:93-104. [PMID: 15847800 DOI: 10.1016/j.jim.2005.01.002] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2004] [Revised: 12/13/2004] [Accepted: 01/14/2005] [Indexed: 11/24/2022]
Abstract
In studies of the relation between structure and function of proteins of the immune system, there is a continuous need for screening of a large number of protein variants. To optimise the yield following transient gene expression in small or medium culture volumes, several parameters were investigated. First, secretion levels of a soluble form of human Fcgamma receptor IIA (FcgammaRIIA) were measured after transfection of 293, 293E, 293T as well as COS-7 cell lines. The transgene was under cytomegalovirus (CMV) promoter control on the expression vector pcDNA3, which also contains an SV40 origin of replication (SV40 ori). All 293 cell lines secreted more protein than COS-7 cells. Introduction of the Epstein Barr virus (EBV) origin of replication (oriP) greatly increased the protein expression from the 293E cells, both the amount of protein produced per day and the duration of production. At best, 293E cells secreted fully functional protein for 3-4 weeks provided supernatant was harvested every 2-3 days followed by medium replacement. This method was then used for expression of soluble forms of human FcgammaRI, FcgammaRIIB, the human neonatal Fc receptor (FcRn), a T cell receptor (TCR)-immunoglobulin (Ig) fusion protein, and human IgG3. With an initial culture volume of 5 ml, the yield was approximately 200 microg for FcgammaRIIA, 1.5 microg for FcgammaRI, 5 microg for FcRn, 20 microg for FcgammaRIIB, 40 microg for the TCR-Ig fusion protein and 850 microg for IgG3. Culture expansion during the 3 weeks of culture further increased the yield. Protein yield was also improved by scaling up the initial volume. This approach can provide sufficient amounts of protein for screening experiments, and in the case of antibody, milligrams of recombinant protein for extensive structural analysis can be obtained from one single transient transfection. The approach should be of interest to laboratories that do not have access to a bioreactor but still have a requirement for reasonable amounts of protein to be produced in an easy and cost-effective manner.
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Affiliation(s)
- Gøril Berntzen
- Department of Molecular Biosciences, University of Oslo, P.O.Box 1041, 0316, Oslo, Norway.
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20
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Guo LH, Zhang W. [Regulation of Fc receptor expression by immune complexes on neutrophils and U937 cells]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 2004; 26:510-4. [PMID: 15562762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
OBJECTIVE To study the regulation of Fc receptor expression by immune complexes (ICs) on neutrophils and U937 cells. METHODS IgA ICs, IgG1 ICs, IgG2 ICs, IgG3 ICs, IgG4 ICs, and IgM ICs were incubated with neutrophils or U937 cells for 1 h. Then their surface Fc receptors were stained by anti-Fc gammaR I, anti-Fc gammaR II , anti-Fc gammaR III, and anti-Fc alphaR I monoclonal antibodies and analyzed by fluorescent activated cell sorting (FACS). RESULTS IgG1 ICs and IgG3 ICs up-regulated Fc gammaR II and Fc gammaR III on U937 cells, Fc gammaR I and Fc alphaR I on neutrophils. Almost all ICs down-regulated Fc gammaR II on neutrophils. CONCLUSIONS ICs can regulate Fc receptor expression on neutrophils and U937 cells, among which IgG1 ICs and IgG3 ICs are most effective.
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Affiliation(s)
- Li-hua Guo
- Department of Immunology, Institute of Basic Medical Sciences, CAMS and PUMC, Beijing 100005, China
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21
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Abstract
Intravenous immunoglobulins (IVIg) are therapeutic preparations of normal human IgG obtained from pools of more than 1000 healthy blood donors. They are currently used in the treatment of a wide range of auto-immune diseases, whether associated with auto-antibodies or auto-reactive T lymphocytes, as well as in the treatment of systemic inflammatory diseases. Several mechanisms of action have been identified during the last 20 years, including: (i) modulation of Fc receptors expression on leukocytes and endothelial cells; (ii) interaction with complement proteins; (iii) modulation of cytokines and chemokines synthesis and release; (iv) modulation of cell proliferation and apoptosis; (v) remyelinisation; (vi) neutralisation of circulating autoantibodies; (vii) selection of repertoires of B and T lymphocytes; (viii) interaction with other cell-surface molecules on lymphocytes and monocytes; (ix) corticosteroid sparing. These mechanisms of action are multiple and often intricate. However, they are still little known and further investigations are warranted.
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Affiliation(s)
- Philippe Guilpain
- Service de médecine interne, Hôpital Cochin, Assistance publique-Hôpitaux de Paris et Université Paris V, Paris
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22
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Woltman AM, Schlagwein N, van der Kooij SW, van Kooten C. The novel cyclophilin-binding drug sanglifehrin A specifically affects antigen uptake receptor expression and endocytic capacity of human dendritic cells. J Immunol 2004; 172:6482-9. [PMID: 15128841 DOI: 10.4049/jimmunol.172.10.6482] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Sanglifehrin A (SFA) is a recently developed immunosuppressant that belongs to the family of immunophilin-binding ligands. SFA is a cyclophilin A-binding immunosuppressive drug with a novel, but unidentified, mechanism of action. Several reports exist about the effect of SFA on T cells, but its effect on the initiators of the immune response, i.e., dendritic cells (DCs), is relatively unknown. Therefore, we examined the effect of SFA on the differentiation and function of human monocyte-derived DCs. Unlike the well-known cyclophilin A-binding immunosuppressant cyclosporin A, which did not affect DC phenotype, differentiation of DCs in the presence of SFA resulted in CD14-CD1a DCs with normal DC morphology, viability, and a proper capacity to activate allogeneic T cells. However, DCs generated in the presence of SFA demonstrated reduced macropinocytosis and lectin-mediated endocytosis, which was in line with a decreased expression of C-type lectins, including mannose receptor, C1qRP, DC-ASGPR, and especially, DC-SIGN. In contrast, FcalphaRI (CD89) and FcgammaRII (CD32) were increased by SFA. The explicit effect of SFA on the expression of Ag uptake receptors and Ag capture by DCs makes SFA unique among immunophilin-binding immunosuppressive drugs.
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Affiliation(s)
- Andrea M Woltman
- Department of Nephrology, Leiden University Medical Center, Leiden, The Netherlands.
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23
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Cianga P, Cianga C, Cozma L, Ward ES, Carasevici E. The MHC class I related Fc receptor, FcRn, is expressed in the epithelial cells of the human mammary gland. Hum Immunol 2004; 64:1152-9. [PMID: 14630397 DOI: 10.1016/j.humimm.2003.08.025] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [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: 10/26/2022]
Abstract
The major histocompatibility complex (MHC) class I related neonatal Fc receptor (FcRn) plays multiple roles, being involved in transporting immunoglobulin G (IgG) and protecting this antibody class from catabolism. The presence of this receptor was previously demonstrated in the lactating murine mammary gland. In the current study we have investigated FcRn expression in various histologic types of human breast carcinoma and lymph node metastases. We used immunohistochemical methods to demonstrate the presence of FcRn in epithelial cells, whereas this Fc receptor could not be detected in mammary gland endothelial cells. The presence of the receptor was also found in the metastasizing epithelial cells within the lymph nodes, and this provides a useful marker for their identification.
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MESH Headings
- Biological Transport
- Breast Neoplasms/immunology
- Breast Neoplasms/metabolism
- Breast Neoplasms/pathology
- Carcinoma, Ductal, Breast/immunology
- Carcinoma, Ductal, Breast/metabolism
- Carcinoma, Ductal, Breast/pathology
- Endothelial Cells/immunology
- Endothelial Cells/metabolism
- Epithelial Cells/immunology
- Epithelial Cells/metabolism
- Female
- Genes, MHC Class I/immunology
- Histocompatibility Antigens Class I
- Humans
- Immunoglobulin G/biosynthesis
- Immunoglobulin G/immunology
- Immunohistochemistry
- Lymphatic Metastasis
- Mammary Glands, Human/immunology
- Mammary Glands, Human/metabolism
- Mammary Glands, Human/pathology
- Pregnancy
- Receptors, Fc/biosynthesis
- Receptors, Fc/immunology
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Affiliation(s)
- Petru Cianga
- Immunology Department, Gr. T. Popa University of Medicine and Pharmacy, Iasi, Romania.
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24
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Pan-Hammarström Q, Wen S, Ghanaat-Pour H, Solders G, Forsberg H, Hammarström L. Lack of correlation between the reduction of serum immunoglobulin concentration and the CTG repeat expansion in patients with type 1 dystrophia [correction of Dystrofia] myotonica. J Neuroimmunol 2004; 144:100-4. [PMID: 14597103 DOI: 10.1016/s0165-5728(03)00271-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [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: 11/17/2022]
Abstract
The length of the CTG repeat in the 3' untranslated region of the DMPK gene is considered to be associated with clinical severity in type 1 Dystrofia Myotonica (DM1) and has also been suggested to correlate with the degree of deficiency of IgG noted in these patients. Total serum level of IgG and IgG subclasses was therefore measured in 61 Swedish patients with DM1, the largest number of patients investigated to date in this respect. Almost half (44%) of the DM1 patients showed a serum concentration of IgG below the normal range. Deficiency of IgG1, IgG2 or IgG3 was noted in 26%, 7% and 20% of the patients, respectively. As transcription of genes 3' of the DMPK gene on chromosome 19 is reduced in DM1 patients, a decreased expression of the alpha chain of the receptor involved in IgG catabolism, FcRn, may theoretically be responsible for the low serum IgG in DM1 patients. No correlation was however found between the number of CTG repeats, levels of FcRn transcripts in either muscle tissue or lymphocytes and serum IgG levels.
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Affiliation(s)
- Qiang Pan-Hammarström
- Division of Clinical Immunology, F79, Department of Laboratory Medicine, Karolinska Institute at Huddinge University Hospital, SE-14186 Stockholm, Sweden
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25
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Abstract
The MHC class I-related receptor, FcRn, plays a central role in regulating the serum levels of IgG. FcRn is expressed in endothelial cells, suggesting that these cells may be involved in maintaining IgG levels. We have used live cell imaging of FcRn-green fluorescent protein transfected human endothelial cells to analyze the intracellular events that control IgG homeostasis. We show that segregation of FcRn-IgG complexes from unbound IgG occurs in the sorting endosome. FcRn or FcRn-IgG complexes are gradually depleted from sorting endosomes to ultimately generate multivesicular bodies whose contents are destined for lysosomal degradation. In addition, the pathways taken by FcRn and the transferrin receptor overlap, despite distinct mechanisms of ligand uptake. The studies provide a dynamic view of the trafficking of FcRn and its ligand and have relevance to understanding how FcRn functions to maintain IgG homeostasis.
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MESH Headings
- Binding Sites, Antibody/genetics
- Cell Line
- Cytoplasmic Vesicles/genetics
- Cytoplasmic Vesicles/immunology
- Cytoplasmic Vesicles/metabolism
- Endosomes/immunology
- Endosomes/metabolism
- Endothelium, Vascular/cytology
- Endothelium, Vascular/immunology
- Endothelium, Vascular/metabolism
- Green Fluorescent Proteins
- Histocompatibility Antigens Class I/metabolism
- Homeostasis/genetics
- Homeostasis/immunology
- Humans
- Immunoglobulin G/genetics
- Immunoglobulin G/metabolism
- Ligands
- Luminescent Proteins/biosynthesis
- Luminescent Proteins/genetics
- Microscopy, Video/methods
- Microtubules/genetics
- Microtubules/immunology
- Microtubules/metabolism
- Protein Transport/genetics
- Protein Transport/immunology
- Receptors, Fc/biosynthesis
- Receptors, Fc/genetics
- Receptors, Fc/metabolism
- Receptors, Fc/physiology
- Receptors, Transferrin/physiology
- Recombinant Fusion Proteins/biosynthesis
- Recombinant Fusion Proteins/metabolism
- Transfection
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Affiliation(s)
- Raimund J Ober
- Cancer Immunobiology Center and Center for Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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26
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Gu W, Holland M, Janssens P, Seamark R, Kerr P. Immune response in rabbit ovaries following infection of a recombinant myxoma virus expressing rabbit zona pellucida protein B. Virology 2004; 318:516-23. [PMID: 14972520 DOI: 10.1016/j.virol.2003.10.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2003] [Revised: 09/24/2003] [Accepted: 10/09/2003] [Indexed: 11/21/2022]
Abstract
In this study, we investigated the autoimmune response in rabbit ovaries following infection with a recombinant myxoma virus expressing rabbit zona pellucida protein B (MV-ZPB). A specific IgG antibody response to ZPB was elicited in the serum of infected rabbits and the antibody strongly bound to the zona pellucida of oocytes in secondary and tertiary follicles. T cell infiltration in the ovary was detected in a small proportion of the infected rabbits. In spite of this, the mean number of preovulatory and tertiary follicles in the ovary was significantly reduced at 30 days postinfection compared with that of the infected and uninfected controls. Histological analysis revealed that the cortex and medulla of these ovaries had accumulated a large number of probably luteinized cells and there were no follicles in these areas, indicating the ovaries were in a severe pathological condition. The data suggest that the delivery of ZP antigens using a recombinant myxoma virus is a prospective way to develop immunocontraceptive vaccines for rabbit population control, but that more understanding of the kinetics of the autoimmune response induced by viral delivery is needed.
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Affiliation(s)
- Wenyi Gu
- Division of Biochemistry and Molecular Biology, the School of Life Sciences, The Australian National University, Canberra, Australia.
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27
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Sprong T, Brandtzaeg P, Fung M, Pharo AM, Høiby EA, Michaelsen TE, Aase A, van der Meer JWM, van Deuren M, Mollnes TE. Inhibition of C5a-induced inflammation with preserved C5b-9-mediated bactericidal activity in a human whole blood model of meningococcal sepsis. Blood 2003; 102:3702-10. [PMID: 12881318 DOI: 10.1182/blood-2003-03-0703] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [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: 11/20/2022] Open
Abstract
The complement system plays an important role in the initial defense against Neisseria meningitidis. In contrast, uncontrolled activation in meningococcal sepsis contributes to the development of tissue damage and shock. In a novel human whole blood model of meningococcal sepsis, we studied the effect of complement inhibition on inflammation and bacterial killing. Monoclonal antibodies (mAbs) blocking lectin and alternative pathways inhibited complement activation by N meningitidis and oxidative burst induced in granulocytes and monocytes. Oxidative burst was critically dependent on CD11b/CD18 (CR3) expression but not on Fc gamma-receptors. Specific inhibition of C5a using mAb 137-26 binding the C5a moiety of C5 before cleavage prohibited CR3 up-regulation, phagocytosis, and oxidative burst but had no effect on C5b-9 (TCC) formation, lysis, and bacterial killing. An mAb-blocking cleavage of C5, preventing C5a and TCC formation, showed the same effect on CR3, phagocytosis, and oxidative burst as the anti-C5a mAb but additionally inhibited TCC formation, lysis, and bacterial killing, consistent with a C5b-9-dependent killing mechanism. In conclusion, the anti-C5a mAb 137-26 inhibits the potentially harmful effects of N meningitidis-induced C5a formation while preserving complement-mediated bacterial killing. We suggest that this may be an attractive approach for the treatment of meningococcal sepsis.
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Affiliation(s)
- Tom Sprong
- Department of General Internal Medicine, University Medical Centre St Radboud Nijmegen, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
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28
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Calum H, Moser C, Jensen PØ, Shirai R, Høiby N. Cytokine and surface receptor diversity of NK cells in resistant C3H/HeN and susceptible BALB/c mice with chronic Pseudomonas aeruginosa lung infection. APMIS 2003; 111:891-7. [PMID: 14510646 DOI: 10.1034/j.1600-0463.2003.1110907.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [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: 11/23/2022]
Abstract
The purpose of the present study was to investigate whether NK cells from resistant C3H/HeN mice and susceptible BALB/c mice showed different release of cytokines and expression of surface molecules during chronic P. aeruginosa lung infection using alginate-embedded P. aeruginosa mimicking the infection in cystic fibrosis. Lung cell suspensions were depleted of lymphocytes by magnetic cell sorting. The concentrations of IFN-gamma, IL-1beta and GM-CSF were estimated by ELISA at day 1 and 2 after infection. Non-infected mice were used as controls. Flow cytometry was used to estimate the surface expression of the LFA-1 and Fc receptors on NK cells. At day 2, IFN-gamma levels increased in C3H/HeN mice but decreased in BALB/c mice. The GM-CSF levels increased only in the C3H/HeN mice at day 1 and 2. Surface expression of LFA-1 on the NK cells was higher in C3H/HeN mice at day 1 and 2. In contrast, the expression of Fc receptors was significantly lower on NK cells in C3H/HeN mice at day 1 and 2. In conclusion, the present results show phenotypic differences in NK cells in the two mice strains in chronic P. aeruginosa lung infection, indicating different modulating effects in the Th1/Th2 balance.
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Affiliation(s)
- Henrik Calum
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark.
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29
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Tze LE, Hippen KL, Behrens TW. Late immature B cells (IgMhighIgDneg) undergo a light chain receptor editing response to soluble self-antigen. J Immunol 2003; 171:678-82. [PMID: 12847233 DOI: 10.4049/jimmunol.171.2.678] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Receptor editing is an important mechanism to modify the Ag specificity of newly developing B cells that are reactive with self-Ags. Previous studies have suggested that late immature B cells, bearing high levels of IgM on their cell surface, are unable to initiate receptor editing and instead are deleted by apoptosis. Using the hen egg lysozyme transgenic system, we show that IgM(high) late-immature B cells are fully capable of receptor editing to soluble self-Ag. This was demonstrated by the induction of new endogenous light chain locus rearrangements and by a single-cell flow cytometric assay using a recombination-activating gene 2-green fluorescence protein reporter transgene. These studies suggest that the developmental window available for immature B cells to edit their Ig receptors, at least in response to certain soluble Ags, extends through the IgM(high) late immature B cell stage.
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MESH Headings
- Animals
- Autoantigens/genetics
- Autoantigens/immunology
- Autoantigens/metabolism
- B-Lymphocyte Subsets/cytology
- B-Lymphocyte Subsets/immunology
- B-Lymphocyte Subsets/metabolism
- Bone Marrow Cells/cytology
- Bone Marrow Cells/immunology
- Bone Marrow Cells/metabolism
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Cells, Cultured
- Immunoglobulin D/biosynthesis
- Immunoglobulin Light Chains/biosynthesis
- Immunoglobulin Light Chains/genetics
- Immunoglobulin Light Chains/metabolism
- Immunoglobulin M/biosynthesis
- Membrane Proteins/genetics
- Membrane Proteins/immunology
- Membrane Proteins/metabolism
- Mice
- Mice, Transgenic
- Muramidase/genetics
- Muramidase/immunology
- Muramidase/metabolism
- RNA Editing/genetics
- RNA Editing/immunology
- Receptors, Antigen, B-Cell/biosynthesis
- Receptors, Antigen, B-Cell/genetics
- Receptors, Antigen, B-Cell/metabolism
- Receptors, Fc/biosynthesis
- Receptors, Fc/genetics
- Receptors, Fc/metabolism
- Solubility
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Affiliation(s)
- Lina E Tze
- Center for Immunology and Department of Medicine, University of Minnesota Medical School, Minneapolis, MN 55455, USA
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30
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Suzuki Y, Gómez-Guerrero C, Shirato I, López-Franco O, Gallego-Delgado J, Sanjuán G, Lázaro A, Hernández-Vargas P, Okumura K, Tomino Y, Ra C, Egido J. Pre-existing glomerular immune complexes induce polymorphonuclear cell recruitment through an Fc receptor-dependent respiratory burst: potential role in the perpetuation of immune nephritis. J Immunol 2003; 170:3243-53. [PMID: 12626583 DOI: 10.4049/jimmunol.170.6.3243] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In immune complex (IC) diseases, FcR are essential molecules facilitating polymorphonuclear cell (PMN) recruitment and effector functions at the IC site. Although FcR-dependent initial tethering and FcR/integrin-dependent PMN accumulation were postulated, their underlying mechanisms remain unclear. We here addressed potential mechanisms involved in PMN recruitment in acute IC glomerulonephritis (nephrotoxic nephritis). Since some renal cells may be recruited from bone marrow (BM) lineages, reconstitution studies with BM chimeras and PMN transfer between wild-type (WT) and FcR-deficient mice (gamma(-/-)) were performed. Severe glomerular damage was induced in WT and W gamma chimeras (BM from WT to irradiated gamma(-/-)), while it was absent in gamma(-/-) and gamma W chimeras (gamma(-/-) BM to WT). Moreover, WT PMN transfer, but not gamma(-/-) PMN, reconstituted the disease in gamma(-/-), indicating that FcR on resident cells is not a prerequisite for PMN recruitment in this disease. Surprisingly, transferred WT PMN were recruited coincidentally with NF-kappa B activation and TNF-alpha overexpression even in glomeruli with preformed IC (nephrotoxic Ab administered 3 days previously), suggesting that PMN can initially be recruited via its own FcR without previous chemoattractant release. Furthermore, H(2)O(2) inhibition by catalase attenuated the acute WT PMN recruitment and the induction of NF-kappa B and TNF-alpha much more than integrin (CD18) blockade, indicating a role for the respiratory burst before integrin-dependent accumulation. In coculture experiments with IC-stimulated PMN and glomeruli, PMN caused acute glomerular TNF-alpha expression predominantly via FcR-mediated H(2)O(2) production. In conclusion, glomerular IC, even preformed, can cause PMN recruitment and injury through PMN FcR-mediated respiratory burst during initial PMN tethering to IC.
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Affiliation(s)
- Yusuke Suzuki
- Renal and Vascular Research Laboratory, Fundación Jiménez Díaz, Autónoma University, Madrid, Spain
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31
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Robbie-Ryan M, Tanzola MB, Secor VH, Brown MA. Cutting edge: both activating and inhibitory Fc receptors expressed on mast cells regulate experimental allergic encephalomyelitis disease severity. J Immunol 2003; 170:1630-4. [PMID: 12574324 DOI: 10.4049/jimmunol.170.4.1630] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mast cell-deficient mice (W/W(v)) exhibit significantly reduced severity of experimental allergic encephalomyelitis (EAE), a murine model of multiple sclerosis. In this study, the contribution of FcR-mediated mast cell activation to disease was examined. W/W(v) mice were reconstituted i.v. with bone marrow-derived mast cells (BMMCs) from wild-type mice or those lacking functional FcRs. Eight weeks later, EAE was induced by immunization with the myelin oligodendrocyte glycoprotein 35-55 peptide. Disease scores were analyzed in reconstituted mice and compared with age-matched W/W(v) mice and wild-type littermates. Mice reconstituted with FcRgamma(-/-) BMMCs or FcgammaRIII(-/-) BMMCs exhibited less severe clinical symptoms similar to W/W(v) controls, while reconstitution with FcRIIB(-/-) BMMCs resulted in disease significantly more severe than wild-type controls. Notably, mice reconstituted with FcgammaRIII(-/-) BMMC exhibit a relapsing-remitting course of disease. These data demonstrate that both activating and inhibitory FcRs expressed on mast cells influence the course of EAE.
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MESH Headings
- Amino Acid Sequence
- Animals
- Autoantibodies/biosynthesis
- Bone Marrow Cells/metabolism
- Bone Marrow Cells/pathology
- Bone Marrow Transplantation
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Encephalomyelitis, Autoimmune, Experimental/epidemiology
- Encephalomyelitis, Autoimmune, Experimental/genetics
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Encephalomyelitis, Autoimmune, Experimental/prevention & control
- Epitopes/immunology
- Female
- Hematopoietic Stem Cell Transplantation
- Hematopoietic Stem Cells/immunology
- Hematopoietic Stem Cells/metabolism
- Hematopoietic Stem Cells/pathology
- Incidence
- Mast Cells/immunology
- Mast Cells/metabolism
- Mast Cells/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Molecular Sequence Data
- Myelin Proteins
- Myelin-Associated Glycoprotein/immunology
- Myelin-Oligodendrocyte Glycoprotein
- Receptors, Fc/biosynthesis
- Receptors, Fc/deficiency
- Receptors, Fc/genetics
- Receptors, Fc/physiology
- Severity of Illness Index
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Affiliation(s)
- Michaela Robbie-Ryan
- Graduate Program in Immunology and Molecular Pathogenesis, Emory University School of Medicine, Atlanta, GA 30322, USA
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32
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Ferlazzo G, Morandi B, D'Agostino A, Meazza R, Melioli G, Moretta A, Moretta L. The interaction between NK cells and dendritic cells in bacterial infections results in rapid induction of NK cell activation and in the lysis of uninfected dendritic cells. Eur J Immunol 2003; 33:306-13. [PMID: 12548561 DOI: 10.1002/immu.200310004] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.3] [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: 11/10/2022]
Abstract
NK and DC reciprocal interactions have only recently been investigated. In this study, we focused on the interplay between NK cells and DC in two models of bacterial infection. Immature monocyte-derived DC were cultured in the presence of live Escherichia coli or bacillus Calmette-Guérin. Upon exposure to either extracellular or intracellular bacteria, DC underwent maturation as assessed by the increased levels of expression of CD80,CD86, and HLA molecules and the de novo expression of CD83 and CCR7. Significant amounts of TNF-alpha and IL-12 were released by DC upon infection, whereas IL-2 and IL-15 were barely detectable in culture supernatants. Both infected and uninfected DC were capable of inducing in fresh autologous NK cells the expression of CD69 and HLA-DR and of inducing cell proliferation. Remarkably, however, infected DC were much stronger inducers of NK cell activation and proliferation than uninfected DC. Thus, after just 24 h of NK/DC coculture, only those NK cells that had been exposed to bacteria-infected DC had acquired the ability to lyse autologous immature DC. In addition, infected DC were more resistant to NK-mediated lysis as a consequence of the up-regulation of HLA class I molecule expression on their surface. This study suggests a regulatory circuit involving NK cells and DC in which DC-induced NK cell activation is effectively enhanced by the presence of pathogens. Activated NK cells, by limiting the supply of immature DC, may then exert a control on subsequent innate and adaptive immune responses.
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MESH Headings
- Antigens, CD/biosynthesis
- Antigens, Differentiation, T-Lymphocyte/biosynthesis
- B7-2 Antigen
- Cells, Cultured/immunology
- Coculture Techniques
- Cytokines/metabolism
- Cytotoxicity, Immunologic
- Dendritic Cells/immunology
- Dendritic Cells/metabolism
- Dendritic Cells/microbiology
- Escherichia coli/immunology
- HLA Antigens/biosynthesis
- HLA-DR Antigens/biosynthesis
- Humans
- Killer Cells, Natural/immunology
- Lectins, C-Type
- Lymphocyte Activation
- Membrane Glycoproteins/biosynthesis
- Mycobacterium bovis/immunology
- Receptors, CCR7
- Receptors, Chemokine/biosynthesis
- Receptors, Fc/biosynthesis
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Affiliation(s)
- Guido Ferlazzo
- Unità di Immunologia, Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy.
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33
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Abstract
More than 10 splice variants of the Fc receptor for IgA (Fc alpha R, CD89) have been identified in human myeloid cells. In this study, we quantified Fc alpha R splice transcripts Delta EC2 and Delta 66 EC2, which lack the entire and a part of the homologous immunoglobulin-like extracellular domain 2 (EC2), respectively. Tumor necrosis factor-alpha was found to specifically increase the ratio of Delta EC2 to the wild type CD89 in neutrophils and conversely decrease the Delta EC2 ratio in monocytes. We also observed a significant decrease in the neutrophil Delta EC2/CD89 ratio in pneumonia patients. These results suggest that Delta EC2 is differentially regulated and could be involved in immunoregulation of IgA-mediated host defense.
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Affiliation(s)
- Shinsaku Togo
- Allergy Research Center, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
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34
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Cameron AJM, McDonald KJ, Harnett MM, Allen JM. Differentiation of the human monocyte cell line, U937, with dibutyryl cyclicAMP induces the expression of the inhibitory Fc receptor, FcgammaRIIb. Immunol Lett 2002; 83:171-9. [PMID: 12095707 DOI: 10.1016/s0165-2478(02)00118-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [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: 11/29/2022]
Abstract
FC receptor for IgG receptor (Fcgamma) mediated activation of macrophages is essential for the clearance of immune complexes and control of inflammation. However, activated macrophages play an integral role in tissue destruction associated with autoimmune and inflammatory disease processes. Understanding the mechanisms which balance activating and inhibitory signals generated by immune complexes are therefore of critical importance to human disease. Here, we demonstrate that differentiation of the human monocytic U937 cell line to a macrophage phenotype with dibutyryl cyclicAMP induces both mRNA and protein expression of the inhibitory IgG receptor, FcgammaRIIb1. We further demonstrate that, following receptor aggregation, FcgammaRII transiently recruits the 5'-inositol phosphatase, SHIP. These data define a role for FcgammaRIIb in the modulation of immune complex mediated macrophage activation in a human model system.
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MESH Headings
- Antigen-Antibody Complex/immunology
- Antigen-Antibody Complex/metabolism
- Antigens, CD/biosynthesis
- Antigens, CD/genetics
- Antigens, CD/immunology
- Blotting, Northern
- Bucladesine/pharmacology
- Cell Differentiation/drug effects
- Cell Differentiation/immunology
- Flow Cytometry
- Humans
- Macrophage Activation/immunology
- Macrophage Activation/physiology
- Monocytes/drug effects
- Monocytes/immunology
- Monocytes/metabolism
- Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases
- Phosphoric Monoester Hydrolases/immunology
- Phosphoric Monoester Hydrolases/metabolism
- RNA, Messenger/analysis
- Receptors, Fc/biosynthesis
- Receptors, Fc/genetics
- Receptors, Fc/immunology
- Receptors, IgG/biosynthesis
- Receptors, IgG/genetics
- Receptors, IgG/immunology
- Reverse Transcriptase Polymerase Chain Reaction
- U937 Cells
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Affiliation(s)
- Angus J M Cameron
- Department of Medicine & Therapeutics, Division of Biochemistry & Molecular Biology, University of Glasgow, Glasgow G12 8QQ, Scotland, UK.
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35
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Wang LY, Wang NL, Yao XS, Miyata S, Kitanaka S. Diterpenes from the roots of Euphorbia kansui and their in vitro effects on the cell division of Xenopus. J Nat Prod 2002; 65:1246-51. [PMID: 12350140 DOI: 10.1021/np0200921] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Twelve polycyclic diterpenes have been isolated from the roots of Euphorbia kansui. Nine were assigned with an ingenol skeleton, 20-O-(2'E,4'E-decadienoyl)ingenol (1), 20-O-(2'E,4'Z-decadienoyl)ingenol (2), 3-O-(2'E,4'Z-decadienoyl)ingenol (3), 3-O-(2'E,4'E-decadienoyl)ingenol (4), 3-O-(2'E,4'Z-decadienoyl)-5-O-acetylingenol (5), 3-O-(2'E,4'Z-decadienoyl)-20-O-acetylingenol (6), 3-O-(2'E,4'E-decadienoyl)-20-O-acetylingenol (7), 20-O-(decanoyl)ingenol (8), and 5-O-(2'E,4'E-decadienoyl)ingenol (9), and three with a jatrophane skeleton, kansuinins A (12), B (11), and C (10). Compounds 1, 2, 5, 9, and 12 are new compounds, while 4 and 7 were assigned with new geometric configurations. Their structures were elucidated by spectroscopic and chemical analysis. In vitro treatment of cultured individual Xenopus cells at the blastular stage with 1-9 arrested cleavage significantly (0.5 microg/mL of each compound resulted in >75% cleavage arrest). Of the three jatrophane diterpenes (10-12), only kansuinin B (11) showed any activity, resulting in 87% cleavage arrest at 50 microg/mL.
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Affiliation(s)
- Li-Yan Wang
- Department of Natural Products Chemistry, Shenyang Pharmaceutical University, Shenhe District Shenyang 110016, People's Pepublic of China
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36
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Davis RS, Li H, Chen CC, Wang YH, Cooper MD, Burrows PD. Definition of an Fc receptor-related gene (FcRX) expressed in human and mouse B cells. Int Immunol 2002; 14:1075-83. [PMID: 12202404 DOI: 10.1093/intimm/dxf074] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [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: 11/14/2022] Open
Abstract
The recent identification of five human Fc receptor (FcR) homologs, hFcRH1-5, has extended the known FcR family and identified an unanticipated richness of the chromosome 1q region in genes encoding potential Ig-binding proteins. In a database search for additional relatives of this family we identified expressed sequence tag representatives of a new FcR-related molecule (hFcRX) and its mouse ortholog (mFcRX). The FcRX cDNAs were cloned from human lymph node and mouse spleen cDNA libraries. hFcRX is located centromeric of FcgammaRII and FcgammaRIII at 1q23, and its mouse ortholog resides in a syntenic region of chromosome 1. The genes encode proteins with 67% interspecies identity that lack both N-linked glycosylation sites and transmembrane regions. Two of the four FcRX domains are Ig-like, and share characteristics similar to FcgammaRI domains 2 and 3, having 28% overall extracellular identity with hFcgammaRI and 27% identity with mFcgammaRI respectively. FcRX transcripts are found primarily in secondary lymphoid tissues, where they are expressed by B lineage cells. FcRX thus may function as a secreted or intracellular protein in normal and neoplastic B cells.
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Affiliation(s)
- Randall S Davis
- Division of Hematology/Oncology, University of Alabama, Bimingham 35294, USA
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37
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Guselnikov SV, Ershova SA, Mechetina LV, Najakshin AM, Volkova OY, Alabyev BY, Taranin AV. A family of highly diverse human and mouse genes structurally links leukocyte FcR, gp42 and PECAM-1. Immunogenetics 2002; 54:87-95. [PMID: 12037601 DOI: 10.1007/s00251-002-0436-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2001] [Revised: 01/21/2002] [Indexed: 11/21/2022]
Abstract
A group of genes encoding proteins structurally related to the leukocyte Fc receptors (FcRs) and termed the IFGP family was identified in human and mouse. Sequences of four human and two mouse cDNAs predict proteins differing by domain composition. One of the mouse cDNAs encodes a secreted protein, which, in addition to four immunoglobulin (Ig)-like domains, contains a scavenger receptor superfamily-related domain at the C-terminus. The other cDNAs code for the type I transmembrane proteins with the extracellular parts comprised of one to six Ig-like domains. Five homologous types of the Ig-like domains were defined and each protein was found to have a unique combination of the domain types. The cytoplasmic tails of the transmembrane proteins show different patterns of the tyrosine-based signal motifs. While the human IFGP members appear to be B-cell antigens, the mouse genes have a broader tissue distribution with predominant expression in brain. Sequence comparisons revealed that the IFGP family may be regarded as a phylogenetic link joining the leukocyte FcRs with the rat NK cell-specific gp42 antigen and platelet endothelial cell adhesion molecule-1 (PECAM-1), two mammalian leukocyte receptors whose close relatives were not found previously. It is suggested that FcRs, the IFGP proteins and gp42 have arisen by a series of duplications from a common ancestor receptor comprised of five Ig-like domains. The organization of the human genes shows that the IFGP family evolved through differential gain and loss of exons due to recombination and/or mutation accumulation in the duplicated copies.
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Affiliation(s)
- Sergei V Guselnikov
- Laboratory of Immunogenetics, Institute of Cytology and Genetics, Lavrentjev st. 10, Novosibirsk 630090, Russia
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38
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Abstract
The blood-brain barrier (BBB) restricts transport of immunoglobulin G (IgG) in the blood to brain direction. However, IgG undergoes rapid efflux in the brain to blood direction via reverse transcytosis across the BBB after direct intracerebral injection. This BBB IgG transport system has the characteristics of an Fc receptor (FcR), but there is no molecular information on the putative BBB FcR. The present study uses confocal microscopy and an antibody to the rat neonatal FcR (FcRn), and demonstrates the expression of the FcRn at the brain microvasculature and choroid plexus epithelium. Co-localization with the Glut1 glucose transporter indicates the brain microvascular FcRn is expressed in the capillary endothelium. The capillary endothelial FcRn may mediate the 'reverse transcytosis' of IgG in the brain to blood direction.
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Affiliation(s)
- Felix Schlachetzki
- Department of Medicine, UCLA School of Medicine, Los Angeles, California 90024, USA
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39
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McDonald KJ, Cameron AJM, Allen JM, Jardine AG. Expression of Fc alpha/mu receptor by human mesangial cells: a candidate receptor for immune complex deposition in IgA nephropathy. Biochem Biophys Res Commun 2002; 290:438-42. [PMID: 11779189 DOI: 10.1006/bbrc.2001.6218] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [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: 12/31/2022]
Abstract
IgA nephropathy is characterized by the deposition of IgA immune complexes in the glomerular mesangium, but the mechanisms responsible for this are not well understood. Human mesangial cells (HMCs) can bind IgA but do not express known IgA receptors. We show here that primary HMCs express mRNA for a novel receptor, the Fc alpha/mu receptor (Fcalpha/muR), and that receptor expression is upregulated by IL-1. We also detected mRNA for a novel receptor variant in HMCs that may encode a soluble form of the receptor. Fcalpha/muR was expressed in a heterologous system which showed that the receptor was approximately 58 kDa in weight and was only minimally N-glycosylated. As predicted from the characteristics of the murine homologue, the expressed human Fcalpha/muR was able to bind IgA and IgM, but not IgG. These results suggest that Fcalpha/muR may be the receptor responsible for mesangial IgA deposition in IgA nephropathy.
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Affiliation(s)
- Kenneth J McDonald
- Renal Unit, Western Infirmary, Dumbarton Road, Glasgow G11 6NT, Scotland, United Kingdom.
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40
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Abstract
Investigation of human genome sequences with a consensus sequence derived from receptors for the Fc region of Igs (FcR) led to the identification of a subfamily of five Ig superfamily members that we term the Fc receptor homologs (FcRHs). The closely linked FcRH genes are located in a chromosome 1q21 region in the midst of previously recognized FcR genes. This report focuses on the FcRH1, FcRH2, and FcRH3 members of this gene family. Their cDNAs encode type I transmembrane glycoproteins with 3-6 Ig-like extracellular domains and cytoplasmic domains containing consensus immunoreceptor tyrosine-based activating and/or inhibitory signaling motifs. The five FcRH genes are structurally related, and their protein products share 28-60% extracellular identity with each other. They also share 15-31% identity with their closest FcR relatives. The FcRH genes are expressed primarily, although not exclusively, by mature B lineage cells. Their conserved structural features, patterns of cellular expression, and the inhibitory and activating signaling potential of their transmembrane protein products suggest that the members of this FcRH multigene family may serve important regulatory roles in normal and neoplastic B cell development.
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MESH Headings
- Amino Acid Sequence
- B-Lymphocytes/metabolism
- Blotting, Northern
- Chromosome Mapping
- Chromosomes, Human, Pair 1/genetics
- Chromosomes, Human, Pair 19/genetics
- Consensus Sequence
- DNA, Complementary/genetics
- Hematologic Neoplasms/genetics
- Hematologic Neoplasms/metabolism
- Humans
- Immunoglobulin Fc Fragments/metabolism
- Molecular Sequence Data
- Multigene Family
- Neoplasm Proteins/genetics
- Organ Specificity
- Phylogeny
- Protein Isoforms/biosynthesis
- Protein Isoforms/chemistry
- Protein Isoforms/genetics
- Receptors, Fc/biosynthesis
- Receptors, Fc/chemistry
- Receptors, Fc/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Alignment
- Sequence Homology, Amino Acid
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Affiliation(s)
- R S Davis
- Divisions of Hematology/Oncology, Department of Medicine, University of Alabama, Birmingham 35294-3300, USA
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41
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Abstract
Acute severe (necrotizing) pancreatitis is often associated with pancreatic or peripancreatic infection. Decreased bacterial clearance due to impaired immune defense may cause local infection. We investigated expressions of surface opsonin receptors (CD11b, complement receptor 3; CD32/CD16, immunoglobulin G Fc receptor) on local and circulatory neutrophils, in murine acute pancreatitis. The mild and severe forms of acute pancreatitis were induced by seven and 13 subcutaneous injections of caerulein, respectively. Peritoneal exudative and circulatory neutrophils were counted and assayed for receptor expressions by flow cytometry, serially at 1-72 hours after pancreatitis induction. Histologically, mild and severe forms showed edematous and necrotizing pancreatitis, respectively. The peritoneal exudative neutrophil count was greater in mild than in severe pancreatitis. Expressions of CD11b and CD32/CD16 on local neutrophils were upregulated early in mild pancreatitis. This upregulation was attenuated in severe pancreatitis. The circulatory neutrophil count was elevated in severe pancreatitis but was unchanged in mild pancreatitis. Opsonin receptor expression on circulatory neutrophils showed a transient, modest upregulation in the early phase of mild pancreatitis. Receptor-positive circulatory neutrophils showed a marked elevation that persisted throughout the course of severe pancreatitis. In conclusion, severe (necrotizing) pancreatitis is associated with reduced opsonin receptor expression on local neutrophils and enhanced expression on circulatory neutrophils, as compared with mild (edematous) pancreatitis. These changes may contribute to local infectious complications and multiple organ failure, in severe pancreatitis.
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MESH Headings
- Acute Disease
- Animals
- Ascitic Fluid/chemically induced
- Ascitic Fluid/metabolism
- Ceruletide/administration & dosage
- Ceruletide/toxicity
- Complement Activation
- Disease Progression
- Drug Administration Schedule
- Edema/chemically induced
- Edema/immunology
- Edema/metabolism
- Edema/pathology
- Female
- Leukocyte Count
- Macrophage-1 Antigen/biosynthesis
- Macrophage-1 Antigen/genetics
- Mice
- Mice, Inbred BALB C
- Neutrophils/metabolism
- Pancreatitis/chemically induced
- Pancreatitis/immunology
- Pancreatitis/metabolism
- Pancreatitis/pathology
- Pancreatitis, Acute Necrotizing/chemically induced
- Pancreatitis, Acute Necrotizing/immunology
- Pancreatitis, Acute Necrotizing/metabolism
- Pancreatitis, Acute Necrotizing/pathology
- Phagocytosis
- Receptors, Fc/biosynthesis
- Receptors, Fc/genetics
- Receptors, IgG/biosynthesis
- Receptors, IgG/genetics
- Receptors, Immunologic/biosynthesis
- Receptors, Immunologic/genetics
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Affiliation(s)
- N Hatano
- The First Department of Surgery, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
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42
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van Egmond M, van Spriel AB, Vermeulen H, Huls G, van Garderen E, van de Winkel JG. Enhancement of polymorphonuclear cell-mediated tumor cell killing on simultaneous engagement of fcgammaRI (CD64) and fcalphaRI (CD89). Cancer Res 2001; 61:4055-60. [PMID: 11358825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
Antibodies can efficiently induce antitumor responses via recruitment of Fc receptor-bearing cytotoxic cells. Polymorphonuclear (PMN) cells represent attractive effector cells for antibody-directed immunotherapy. This, because activated PMN cells coexpress the class I receptors for IgG (FcgammaRI, CD64) and IgA (FcalphaRI, CD89), which are potent cytotoxic trigger molecules. Both receptors, however, require the FcR gamma chain for signaling. In this study, we show that FcgammaRI and FcalphaRI can trigger function independently of one another and do not cross-compete for the FcR gamma chain. FcalphaRI proved more efficient in initiating early signaling events and effector functions, such as redirected tumor cell killing and generation of superoxide. In addition, simultaneous engagement of FcgammaRI and FcalphaRI resulted in enhanced tumor cell lysis. These data support the development of concepts in which both FcgammaRI and FcalphaRI on PMN cells are targeted for tumor therapy.
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MESH Headings
- Animals
- Antigens, CD/biosynthesis
- Antigens, CD/genetics
- Antigens, CD/immunology
- Breast Neoplasms/immunology
- Cytotoxicity, Immunologic/immunology
- Female
- Granulocyte-Macrophage Colony-Stimulating Factor/pharmacology
- Humans
- Male
- Mice
- Multiple Myeloma/immunology
- Neutrophils/drug effects
- Neutrophils/immunology
- Receptors, Fc/biosynthesis
- Receptors, Fc/genetics
- Receptors, Fc/immunology
- Receptors, IgG/biosynthesis
- Receptors, IgG/genetics
- Receptors, IgG/immunology
- Signal Transduction/immunology
- Tumor Cells, Cultured
- Tumor Necrosis Factor-alpha/pharmacology
- Up-Regulation
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Affiliation(s)
- M van Egmond
- Department of Cell Biology/Immunology, Vrije Universiteit, Amsterdam, the Netherlands
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43
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Zhu X, Meng G, Dickinson BL, Li X, Mizoguchi E, Miao L, Wang Y, Robert C, Wu B, Smith PD, Lencer WI, Blumberg RS. MHC class I-related neonatal Fc receptor for IgG is functionally expressed in monocytes, intestinal macrophages, and dendritic cells. J Immunol 2001; 166:3266-76. [PMID: 11207281 PMCID: PMC2827247 DOI: 10.4049/jimmunol.166.5.3266] [Citation(s) in RCA: 226] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The neonatal Fc receptor (FcRn) for IgG, an MHC class I-related molecule, functions to transport IgG across polarized epithelial cells and protect IgG from degradation. However, little is known about whether FcRn is functionally expressed in immune cells. We show here that FcRn mRNA was identifiable in human monocytes, macrophages, and dendritic cells. FcRn heavy chain was detectable as a 45-kDa protein in monocytic U937 and THP-1 cells and in purified human intestinal macrophages, peripheral blood monocytes, and dendritic cells by Western blot analysis. FcRn colocalized in vivo with macrosialin (CD68) and Ncl-Macro, two macrophage markers, in the lamina propria of human small intestine. The heavy chain of FcRn was associated with the beta(2)-microglobulin (beta(2)m) light chain in U937 and THP-1 cells. FcRn bound human IgG at pH 6.0, but not at pH 7.5. This binding could be inhibited by human IgG Fc, but not Fab. FcRn could be detected on the cell surface of activated, but not resting, THP-1 cells. Furthermore, FcRn was uniformly present intracellularly in all blood monocytes and intestinal macrophages. FcRn was detectable on the cell surface of a significant fraction of monocytes at lower levels and on a small subset of tissue macrophages that expressed high levels of FcRn on the cell surface. These data show that FcRn is functionally expressed and its cellular distribution is regulated in monocytes, macrophages, and dendritic cells, suggesting that it may confer novel IgG binding functions upon these cell types relative to typical Fc gamma Rs: Fc gamma RI, Fc gamma RII, and Fc gamma RIII.
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MESH Headings
- Adult
- Antibody Specificity/genetics
- Biomarkers
- Cell Line
- Dendritic Cells/immunology
- Dendritic Cells/metabolism
- HLA Antigens/physiology
- HeLa Cells
- Histocompatibility Antigens Class I/physiology
- Humans
- Hydrogen-Ion Concentration
- Immunoglobulin Fc Fragments/physiology
- Immunoglobulin G/metabolism
- Immunoglobulin Heavy Chains/metabolism
- Infant, Newborn
- Intestinal Mucosa/cytology
- Intestinal Mucosa/immunology
- Intestinal Mucosa/metabolism
- Jurkat Cells
- Macrophages/metabolism
- Monocytes/immunology
- Monocytes/metabolism
- Organ Specificity/immunology
- Protein Binding/immunology
- Protein Structure, Tertiary/genetics
- Receptors, Fc/biosynthesis
- Receptors, Fc/chemistry
- Receptors, Fc/genetics
- Receptors, Fc/metabolism
- Receptors, IgG/biosynthesis
- Receptors, IgG/chemistry
- Receptors, IgG/genetics
- Receptors, IgG/metabolism
- Transfection
- Tumor Cells, Cultured
- U937 Cells
- beta 2-Microglobulin/metabolism
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Affiliation(s)
- Xiaoping Zhu
- Gastroenterology Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115
| | - Gang Meng
- Department of Medicine, University of Alabama and Veteran’s Affairs Medical Center, Birmingham, AL 35294
| | - Bonny L. Dickinson
- Combined Program in Pediatric Gastroenterology and Nutrition, Children’s Hospital, Harvard Medical School, Boston, MA 02115
| | - Xiaotong Li
- Departments of Medicine and Pathology, Children’s Hospital, Harvard Medical School, Boston, MA 02115
| | - Emiko Mizoguchi
- Departments of Medicine and Pathology, Children’s Hospital, Harvard Medical School, Boston, MA 02115
| | - Lili Miao
- Gastroenterology Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115
| | - Yuansheng Wang
- Departments of Medicine and Pathology, Children’s Hospital, Harvard Medical School, Boston, MA 02115
| | - Caroline Robert
- Departments of Medicine and Pathology, Children’s Hospital, Harvard Medical School, Boston, MA 02115
| | - Benyan Wu
- Gastroenterology Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115
| | - Phillip D. Smith
- Department of Medicine, University of Alabama and Veteran’s Affairs Medical Center, Birmingham, AL 35294
| | - Wayne I. Lencer
- Combined Program in Pediatric Gastroenterology and Nutrition, Children’s Hospital, Harvard Medical School, Boston, MA 02115
| | - Richard S. Blumberg
- Gastroenterology Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115
- Address correspondence and reprint requests to Dr. Richard S. Blumberg, Gastroenterology Division, Brigham and Women’s Hospital, 75 Francis Street, Boston, MA 02115.
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44
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Antohe F, Rădulescu L, Gafencu A, Gheţie V, Simionescu M. Expression of functionally active FcRn and the differentiated bidirectional transport of IgG in human placental endothelial cells. Hum Immunol 2001; 62:93-105. [PMID: 11182218 DOI: 10.1016/s0198-8859(00)00244-5] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.9] [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: 11/24/2022]
Abstract
The mechanism of selective transport of the immunoglobulins G from the placental stroma to the lumen of the fetal blood vessels has not been elucidated yet. It was postulated that the specific transport as well as the regulation of IgG level in the blood, involves the MHC class I related receptor FcRn for the Fc domain of IgG. We questioned whether human placental endothelial cells (HPEC) express FcRn and, if present, whether it is in a functionally active form. The experiments were performed on cultured HPEC and as positive control, human trophoblastic (JEG3) and mouse endothelial cells (SVEC) were used. Expression of FcRn, was demonstrated by indirect immunofluorescence and RT-PCR. The role of FcRn was assessed by quantifying the transcellular transport of [(125)I]-hIgG or [(125)I]-rF(ab')(2) fragments from the apical to basolateral surface, and in the reverse direction of HPEC grown on filters in a double chamber system. The intracellular pathway of FcRn or IgG was examined by electron microscopy using the proteins adsorbed to 5 nm and 20 nm colloidal gold particles, respectively. The results showed that: (a) FcRn is expressed by human placental endothelial cells, in a functionally active form; (b) transcytosis of IgG in HPEC is a time-dependent process that takes place preferentially from the basolateral to the apical compartment; and (c) both IgG and FcRn colocalize in an intracellular endocytic compartment, chloroquine sensitive. Together these data suggest that the regulation of IgG level by endothelial cells may result from interplay between salvaging, exocytosis, and transcytosis of the molecules. One can assume that IgG that does not bind to FcRn may be destined for destruction, and this would explain the mechanism by which IgG homeostasis is maintained.
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MESH Headings
- Animals
- Biological Transport, Active/immunology
- Cell Line, Transformed
- Cells, Cultured
- Endothelium, Vascular/cytology
- Endothelium, Vascular/immunology
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/ultrastructure
- Female
- Fluorescent Antibody Technique, Indirect
- Histocompatibility Antigens Class I
- Humans
- Immunity, Maternally-Acquired
- Immunoglobulin G/metabolism
- Immunoglobulin G/ultrastructure
- Mice
- Mice, Inbred C3H
- Microscopy, Electron
- Placenta/blood supply
- Placenta/immunology
- Placenta/metabolism
- Placenta/ultrastructure
- Pregnancy
- RNA, Messenger/analysis
- Receptors, Fc/biosynthesis
- Receptors, Fc/genetics
- Receptors, Fc/physiology
- Receptors, Fc/ultrastructure
- Reverse Transcriptase Polymerase Chain Reaction
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Affiliation(s)
- F Antohe
- Institute of Cellular Biology and Pathology "Nicolae Simionescu" , Bucharest, Romania
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45
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Honorio-França AC, Launay P, Carneiro-Sampaio MM, Monteiro RC. Colostral neutrophils express Fc alpha receptors (CD89) lacking gamma chain association and mediate noninflammatory properties of secretory IgA. J Leukoc Biol 2001; 69:289-96. [PMID: 11272280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
Colostrum plays an important role in protecting newborn infants against acute gastrointestinal and respiratory infections. IgA antibodies have been considered the major effector component; however, the role of their receptors on colostral phagocytes, especially neutrophils, has not been studied. Here, we demonstrate that CD15+ colostrum neutrophils express IgA Fc receptors (Fc alphaR, CD89) at levels similar to those of blood neutrophils. Most colostral cells (70%) bear secretory IgA (SIgA) on their surface (and intracellularly), whereas blood cells do not. The Fc alphaR on colostral neutrophils was identified as the a.1 isoform with a similar molecular mass (55-75 kDa) as that identified for blood neutrophils. Removal of N-linked carbohydrates revealed a major protein core of 32 kDa for both cell types. In contrast, co-immunoprecipitation and immunoblot experiments using a mild detergent, digitonin, revealed a lack of gamma chain association with Fc alphaR (gamma-less) exclusively on colostral neutrophils. The functional role of these gamma-less Fc alphaR cells was evaluated by measuring superoxide release and killing of SIgA-coated enteropathogenic E. coli. No increase in superoxide release was observed in colostral cells compared with blood neutrophils, whereas optimal release was obtained with PMA stimulation. Furthermore, despite similar bacterial phagocytosis index between both cell types, IgA-mediated bacterial-killing was not detectable with colostral neutrophils, whereas killing was detectable on blood cells. These results reveal exclusive expression of gamma-less Fc alphaR on colostral neutrophils associated with receptor hyperoccupation by IgA and with low, bacterial-killing activity, which suggest that this receptor may mediate noninflammatory effects of SIgA.
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Affiliation(s)
- A C Honorio-França
- Department of Immunology of Instituto de Ciências Biomédicas, University of São Paulo, SP, Brazil
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46
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Geissmann F, Launay P, Pasquier B, Lepelletier Y, Leborgne M, Lehuen A, Brousse N, Monteiro RC. A subset of human dendritic cells expresses IgA Fc receptor (CD89), which mediates internalization and activation upon cross-linking by IgA complexes. J Immunol 2001; 166:346-52. [PMID: 11123311 DOI: 10.4049/jimmunol.166.1.346] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Immature dendritic cells (DC) sample Ags within nonlymphoid tissues and acquire exogenous proteins/pathogens via scavenger receptors or Ig FcR such as Fc gamma R and Fc epsilon R. IgA is present in a significant proportion among serum Ig and is the main isotype in mucosae, where DC are numerous. We found that a functional Fc alpha R (CD89) was expressed in situ and in vitro on interstitial-type DC but not on Langerhans cell-type DC. Interstitial-type DC expressed CD89 as a 50- to 75-kDa glycoprotein with a 32-kDa protein core, which was down-regulated upon addition of TGF-beta 1. DC, Fc alpha R specifically, bound IgA1 and IgA2. Cross-linking of CD89 on DC triggered endocytosis in time-dependent manner. In addition, internalization of polymeric IgA complexes induced the production of IL-10 and DC activation, as reflected by up-regulation of CD86 costimulatory molecules, class II MHC expression, and increased allostimulatory activity. Therefore, interstitial-type DC may use Fc alpha R-mediated Ag sampling in the subepithelium to check tissue integrity while Langerhans cells inside epithelial layers may neglect IgA immune complexes.
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MESH Headings
- Antigen-Antibody Complex/metabolism
- Antigens, CD/biosynthesis
- Antigens, CD/immunology
- Antigens, CD/metabolism
- Antigens, CD/physiology
- B7-2 Antigen
- Binding Sites, Antibody
- Cells, Cultured
- Dendritic Cells/classification
- Dendritic Cells/immunology
- Dendritic Cells/metabolism
- Dermis/immunology
- Dermis/metabolism
- Epidermis/immunology
- Epidermis/metabolism
- Extracellular Space/immunology
- Extracellular Space/metabolism
- Histocompatibility Antigens Class II/biosynthesis
- Humans
- Immunoglobulin A/metabolism
- Interleukin-10/metabolism
- Langerhans Cells/immunology
- Langerhans Cells/metabolism
- Lymphocyte Activation/immunology
- Macrophages/immunology
- Macrophages/metabolism
- Membrane Glycoproteins/biosynthesis
- Monocytes/immunology
- Monocytes/metabolism
- Protein Binding/immunology
- Receptors, Fc/biosynthesis
- Receptors, Fc/immunology
- Receptors, Fc/metabolism
- Receptors, Fc/physiology
- U937 Cells
- Up-Regulation/immunology
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Affiliation(s)
- F Geissmann
- Institut Fédératif de Recherche Necker-Enfants Malades, Unité Mixte de Recherche 8603, Centre National de la Recherche Scientifique/Université Paris-V, France.
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47
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Cowan FM, Broomfield CA, Smith WJ. Exposure of human epidermal keratinocyte cell cultures to sulfur mustard promotes binding of complement C1q: implications for toxicity and medical countermeasures. J Appl Toxicol 2000; 20 Suppl 1:S77-80. [PMID: 11428648 DOI: 10.1002/1099-1263(200012)20:1+<::aid-jat686>3.0.co;2-e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 11/07/2022]
Abstract
Sulfur mustard (HD)-increased proteolytic activity, HD-enhanced expression of Fc receptor (FcR) on human epidermal keratinocytes (HEK) and associated inflammatory responses may contribute to HD pathology. Like the FcR, the first component of the classical complement (C') cascade, C1q, binds to the Fc region of antibody to mediate inflammatory responses. Complement C1q binds specifically to the C1q receptor (C1qR) on the blebs of apoptotic human keratinocytes and is proposed as a cell surface marker for apoptosis. Assays by fluorescent antibodies demonstrated significantly enhanced binding of C1q to HEK cell cultures exposed to HD. The cell populations of HEK that showed enhanced C1q binding also demonstrated an intermediate uptake of propidium iodide that was greater than in viable unexposed cells but less than in dead cells. The HD-enhanced C1q binding was concentration-dependent, negative by flow cytometry or weakly positive by digital scanning microscopy at 100 microM and positive by both methods at 300 microM. Binding of C1q was also time-dependent, weakly positive at 8 h, and positive at 16 and 24 h after HD exposure. The HD-increased C1qR that binds C1q to the surface of HEK might be a contributing mechanism or a marker for the inflammation and vesication associated with HD exposure.
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Affiliation(s)
- F M Cowan
- Biochemical Pharmacology Branch, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010-5425, USA
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48
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Stockmeyer B, Dechant M, van Egmond M, Tutt AL, Sundarapandiyan K, Graziano RF, Repp R, Kalden JR, Gramatzki M, Glennie MJ, van de Winkel JG, Valerius T. Triggering Fc alpha-receptor I (CD89) recruits neutrophils as effector cells for CD20-directed antibody therapy. J Immunol 2000; 165:5954-61. [PMID: 11067958 DOI: 10.4049/jimmunol.165.10.5954] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD20 Abs induce clinical responses in lymphoma patients, but there are considerable differences between individual patients. In (51)Cr release assays with whole blood as effector source, RAJI cells were effectively killed by a mouse/human chimeric IgG1 construct of CD20 Ab 1F5, whereas ARH-77 proved resistant to killing by this Ab. When whole blood was fractionated into plasma, mononuclear cells, or granulocytic effector cells, RAJI cells were effectively killed in the presence of complement-containing plasma, whereas the mature B cell line ARH-77 proved complement resistant. However, with a bispecific Ab (BsAb) against the myeloid receptor for IgA (CD89; FcalphaRI) and CD20, a broad range of B cell lines were effectively killed. FcalphaRI is expressed on monocytes/macrophages, neutrophils, and eosinophils. As the numbers of these effector cells and their functional activity can be enhanced by application of G-CSF or GM-CSF, lysis via (FcalphaRI x CD20) BsAb was significantly enhanced in blood from patients during therapy with these myeloid growth factors. Interestingly, the major effector cell population for this BsAb were polymorphonuclear neutrophils, which proved ineffective in killing malignant B cells with murine, chimeric IgG1, or FcgammaRI- or FcgammaRIII-directed BsAbs against CD20. Experiments with blood from human FcalphaRI/FcgammaRI double-transgenic mice showed corresponding results, allowing the establishment of relevant syngenic animal models in these mice. In conclusion, the combination of myeloid growth factors and an (FcalphaRI x CD20) BsAb may represent a promising approach to improve effector cell recruitment for CD20-directed lymphoma therapy.
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MESH Headings
- Animals
- Antibodies, Bispecific/genetics
- Antibodies, Bispecific/pharmacology
- Antibodies, Bispecific/therapeutic use
- Antibodies, Monoclonal/genetics
- Antibodies, Monoclonal/pharmacology
- Antibodies, Monoclonal/therapeutic use
- Antibodies, Neoplasm/genetics
- Antibodies, Neoplasm/pharmacology
- Antibody-Dependent Cell Cytotoxicity/genetics
- Antigens, CD/biosynthesis
- Antigens, CD/blood
- Antigens, CD/physiology
- Antigens, CD20/immunology
- Antineoplastic Agents/pharmacology
- Granulocyte Colony-Stimulating Factor/pharmacology
- Granulocyte-Macrophage Colony-Stimulating Factor/pharmacology
- Growth Inhibitors/pharmacology
- Humans
- Immunoglobulin A/metabolism
- Immunoglobulin G/genetics
- Immunoglobulin G/pharmacology
- Lymphoma, B-Cell/genetics
- Lymphoma, B-Cell/immunology
- Lymphoma, B-Cell/therapy
- Mice
- Mice, Transgenic
- Neutrophil Infiltration/immunology
- Receptors, Fc/biosynthesis
- Receptors, Fc/blood
- Receptors, Fc/physiology
- Receptors, IgG/biosynthesis
- Receptors, IgG/blood
- Receptors, IgG/genetics
- Recombinant Fusion Proteins/immunology
- Recombinant Fusion Proteins/pharmacology
- Tumor Cells, Cultured
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Affiliation(s)
- B Stockmeyer
- Division of Hematology/Oncology, Department of Medicine III, University of Erlangen-Nürnberg, Erlangen, Germany.
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49
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Jodo S, Hohlbaum AM, Xiao S, Chan D, Strehlow D, Sherr DH, Marshak-Rothstein A, Ju ST. CD95 (Fas) ligand-expressing vesicles display antibody-mediated, FcR-dependent enhancement of cytotoxicity. J Immunol 2000; 165:5487-94. [PMID: 11067901 DOI: 10.4049/jimmunol.165.10.5487] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Bioactive Fas ligand (FasL)-expressing vesicles were generated (vesicle preparation, VP) from two cell lines overexpressing FasL. The effect of NOK-1 anti-FasL mAb (mouse IgG1) on the cytotoxicity of FasL VP against various targets was determined. At high concentrations (1-10 microg/ml), NOK-1 inhibited the cytotoxicity. By contrast, NOK-1 in the dose range of 1-100 ng/ml significantly enhanced cytotoxicity against the FcR(+) LB27.4, M59, and LF(+) targets, but not the FcR(-) Jurkat and K31H28 hybridoma T cell targets. The ability to enhance FasL VP-mediated cytotoxicity could be blocked by the FcR-specific mAb 2.4G2. Enhancement was also observed with FcR(+) A20 B lymphoma but not with the FcR(-) A20 variant. Enhancement of FasL VP cytotoxicity was observed with five IgG anti-FasL mAbs, but not with an IgM anti-FasL mAb. Inhibition was observed with high doses of all mAb except the IgG anti-FasL mAb G247-4, which is specific to a segment outside the FasL binding site. Interestingly, under identical conditions but in the presence of 2.4G2, G247-4 inhibited the cytotoxicity of FasL VP. In addition, G247-4 inhibited the FasL VP-mediated killing of FcR(-) Jurkat. The data demonstrate that FasL-expressing bioactive vesicles display a property heretofore unknown in bioactive agents that express FasL-mediated cytotoxicity. The mechanism of the Ab-mediated, FcR-dependent enhancement of cytotoxicity of bioactive vesicles and its physiological significance are discussed.
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Affiliation(s)
- S Jodo
- The Arthritis Center, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
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50
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Phillips-Quagliata JM, Patel S, Han JK, Arakelov S, Rao TD, Shulman MJ, Fazel S, Corley RB, Everett M, Klein MH, Underdown BJ, Corthésy B. The IgA/IgM receptor expressed on a murine B cell lymphoma is poly-Ig receptor. J Immunol 2000; 165:2544-55. [PMID: 10946281 DOI: 10.4049/jimmunol.165.5.2544] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
T560, a mouse B lymphoma that originated in gut-associated lymphoid tissue, expresses receptors that bind dimeric IgA and IgM in a mutually inhibitory manner but have little affinity for monomeric IgA. Evidence presented in this paper indicates that the receptor is poly-Ig receptor (pIgR) known in humans and domestic cattle to bind both IgA and IgM. The evidence includes the demonstration that binding of IgM is J chain dependent, and that pIg-precipitated receptor has an appropriate Mr of 116-120 kDa and can be detected on immunoblots with specific rabbit anti-mouse pIgR. Overlapping RT-PCR performed using template mRNA from T560 cells and oligonucleotide primer pairs designed from the published sequence of mouse liver pIgR indicate that T560 cells express mRNA virtually identical with that of the epithelial cell pIgR throughout its external, transmembrane, and intracytoplasmic coding regions. Studies using mutant IgAs suggest that the Calpha2 domain of dimeric IgA is not involved in high-affinity binding to the T560 pIgR. Inasmuch as this mouse B cell pIgR binds IgM better than IgA, it is similar to human pIgR and differs from rat, mouse, and rabbit epithelial cell pIgRs that bind IgA but not IgM. Possible explanations for this difference are discussed. All clones of T560 contain some cells that spontaneously secrete both IgG2a and IgA, but all of the IgA recoverable from the medium and from cell lysates is monomeric; it cannot be converted to secretory IgA by T560 cells.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Binding Sites, Antibody
- Binding, Competitive/immunology
- Carbohydrate Metabolism
- Carbohydrates/immunology
- Chemical Precipitation
- Cross Reactions
- Enzyme Activation/immunology
- Epitopes, B-Lymphocyte/metabolism
- Epitopes, T-Lymphocyte/metabolism
- Humans
- Immunoblotting
- Immunoglobulin A/metabolism
- Immunoglobulin A, Secretory/metabolism
- Immunoglobulin J-Chains/physiology
- Immunoglobulin M/metabolism
- Lymphoma, B-Cell/immunology
- Lymphoma, B-Cell/metabolism
- Mice
- Mice, Inbred BALB C
- Molecular Sequence Data
- Molecular Weight
- Phosphatidylinositol Diacylglycerol-Lyase
- Protein Kinase C/metabolism
- RNA, Messenger/biosynthesis
- Rats
- Receptors, Fc/biosynthesis
- Receptors, Fc/isolation & purification
- Receptors, Polymeric Immunoglobulin/biosynthesis
- Receptors, Polymeric Immunoglobulin/genetics
- Receptors, Polymeric Immunoglobulin/isolation & purification
- Tumor Cells, Cultured
- Type C Phospholipases/metabolism
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Affiliation(s)
- J M Phillips-Quagliata
- Department of Pathology, New York University School of Medicine and Kaplan Cancer Center, New York, NY 10016, USA.
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