1
|
Wu J, Li Y, Rendahl A, Bhargava M. Novel Human FCGR1A Variants Affect CD64 Functions and Are Risk Factors for Sarcoidosis. Front Immunol 2022; 13:841099. [PMID: 35371020 PMCID: PMC8968912 DOI: 10.3389/fimmu.2022.841099] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/24/2022] [Indexed: 12/19/2022] Open
Abstract
CD64 (or FcγRIA) is the sole functional high affinity IgG Fc receptor coded by FCGR1A gene in humans. The FCGR1A genetics has not been comprehensively investigated and effects of human FCGR1A variants on immune functions remain unknown. In the current study, we identified three novel FCGR1A variants including the single nucleotide variant (SNV) rs1848781 (c.-131) in the proximal FCGR1A gene promoter region, the rs587598788 indel variant within the FCGR1A intron 5, and the non-synonymous SNV rs1050204 (c.970G>A or FcγRIA-p.D324N) in the FCGR1A coding region. Genotype-phenotype analyses revealed that SNV rs1848781 genotypes were significantly associated with CD64 expression levels. Promoter reporter assays show that rs1848781G allele had significantly higher promoter activity than the rs1848781C, confirming that the rs1848781 is a functional FCGR1A SNV affecting promoter activity and gene expression. The rs587598788 indel genotypes were also significantly associated with levels of CD64 expression. Moreover, the non-synonymous SNV rs1050204 (FcγRIA-p.D324N) alleles significantly affected CD64-mediated phagocytosis, degranulation, and pro-inflammatory cytokine productions. Genetic analyses revealed that FCGR1A genotypes were significantly associated with sarcoidosis susceptibility and severity. Our data suggest that FCGR1A genetic variants may affect immune responses and play a role in sarcoidosis.
Collapse
Affiliation(s)
- Jianming Wu
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
- *Correspondence: Jianming Wu, ; orcid.org/000-0001-9142-7066
| | - Yunfang Li
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| | - Aaron Rendahl
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| | - Maneesh Bhargava
- Division of Pulmonary, Allergy, Critical Care & Sleep Medicine, Department of Medicine, School of Medicine, University of Minnesota, Minneapolis, MN, United States
| |
Collapse
|
2
|
Matos MC, Pinheiro A, Melo-Ferreira J, Davis RS, Esteves PJ. Evolution of Fc Receptor-Like Scavenger in Mammals. Front Immunol 2021; 11:590280. [PMID: 33708190 PMCID: PMC7940838 DOI: 10.3389/fimmu.2020.590280] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 12/31/2020] [Indexed: 11/13/2022] Open
Abstract
Fc receptor-like (FCRL) molecules comprise a large family of receptors, homologous to the receptors for the Fc portion of immunoglobulins (FCR). Within this family, an unusual gene known to exist in mice, rats and dogs, termed FCRLS, encodes a chimeric protein with both Ig-like FCRL and type B scavenger-receptor cysteine-rich (SRCR)-like domains. In mice, FCRLS is located next to the CD5L and KIRREL1 genes. Here, we show that the curious FCRLS gene is actually present across major mammalian groups, but its annotation is generally incorrect or absent. Anchored on mouse FCRLS and FCRL2 genomic sequence alignments, phylogenetic analyses demonstrated that many mammalian sequences currently annotated as FCRL2 cluster with FCRLS, supported by a conserved genetic synteny among organisms. This analysis shows that FCRLS is present in Rodentia, some Carnivora (Canidae and Ursidae), Chiroptera, Arctiodactyla, Proboscidae, and some Primata. Thus, the FCRLS most likely originated in a eutherian mammal ancestor since it is not present in Monotremata or Marsupialia. FCRLS has a peculiar distribution pattern across mammalian lineages, being present in some species, but absent in others from the same family, as in carnivores for example. The most parsimonious hypothesis to explain this FCRLS evolution is that it was convergently lost in several independent mammalian lineages. Analyses of branch-specific nucleotide evolutionary rates, show that FCRL2 and FCRLS have similar ranges of rates across mammals, suggesting that both genes have crucial, but separate functions in the immune system. Bayesian estimates of evolutionary rates for FCRLS in mammalian lineages revealed that carnivores display the highest mutation rate after rodents. Additionally, positive diversifying selection was detected for both FCRL2 and FCRLS. Our results show that the presence of the FCRLS gene is older and more widespread across mammals than previously thought and appears to be functional, being under positive selection. Its precise physiologic role should thus be investigated.
Collapse
Affiliation(s)
- Maria Carolina Matos
- Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO-UP), Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Laboratório Associado, Universidade do Porto, Vairão, Portugal.,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| | - Ana Pinheiro
- Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO-UP), Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Laboratório Associado, Universidade do Porto, Vairão, Portugal
| | - José Melo-Ferreira
- Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO-UP), Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Laboratório Associado, Universidade do Porto, Vairão, Portugal.,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| | - Randall S Davis
- Departments of Medicine, Microbiology, and Biochemistry & Molecular Genetics and the Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Pedro José Esteves
- Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO-UP), Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Laboratório Associado, Universidade do Porto, Vairão, Portugal.,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal.,CITS - Centro de Investigação em Tecnologias de Saúde, Cooperativa de Ensino Superior Politécnico e Universitário, CRL (CESPU), Gandra, Portugal
| |
Collapse
|
3
|
Dixon KJ, Wu J, Walcheck B. Engineering Anti-Tumor Monoclonal Antibodies and Fc Receptors to Enhance ADCC by Human NK Cells. Cancers (Basel) 2021; 13:312. [PMID: 33467027 PMCID: PMC7829765 DOI: 10.3390/cancers13020312] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 01/13/2021] [Accepted: 01/13/2021] [Indexed: 02/06/2023] Open
Abstract
Tumor-targeting monoclonal antibodies (mAbs) are the most widely used and characterized immunotherapy for hematologic and solid tumors. The significance of this therapy is their direct and indirect effects on tumor cells, facilitated by the antibody's antigen-binding fragment (Fab) and fragment crystallizable region (Fc region), respectively. The Fab can modulate the function of cell surface markers on tumor cells in an agonistic or antagonistic manner, whereas the Fc region can be recognized by an Fc receptor (FcR) on leukocytes through which various effector functions, including antibody-dependent cell-mediated cytotoxicity (ADCC), can be elicited. This process is a key cytolytic mechanism of natural killer (NK) cells. These innate lymphocytes in the human body recognize tumor-bound antibodies exclusively by the IgG Fc receptor CD16A (FcγRIIIA). Two allelic versions of CD16A bind IgG with either lower or higher affinity. Cancer patients homozygous for the higher affinity allele of CD16A have been reported to respond significantly better to mAb therapies for various malignancies. These studies revealed that mAb therapy efficacy positively correlates with higher affinity binding to CD16A. Approaches to enhance tumor antigen targeting by NK cells by modifying the Fc portion of antibodies or the FcR on NK cells are the focus of this review.
Collapse
Affiliation(s)
| | | | - Bruce Walcheck
- Department of Veterinary and Biomedical Sciences, University of Minnesota, Saint Paul, MN 55108, USA; (K.J.D.); (J.W.)
| |
Collapse
|
4
|
Le LTM, Nyengaard JR, Golas MM, Sander B. Vectors for Expression of Signal Peptide-Dependent Proteins in Baculovirus/Insect Cell Systems and Their Application to Expression and Purification of the High-Affinity Immunoglobulin Gamma Fc Receptor I in Complex with Its Gamma Chain. Mol Biotechnol 2018; 60:31-40. [PMID: 29143175 DOI: 10.1007/s12033-017-0041-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Integral membrane proteins play a central role in various cellular functions and are important therapeutic targets. However, technical challenges in the overexpression and purification of membrane proteins often represent a limiting factor for biochemical and structural studies. Here, we constructed a set of vectors, derivatives of MultiBac vectors that can be used to express proteins with a cleavable N-terminal signal peptide in insect cells. We propose these vectors for expression of type I membrane proteins and other secretory pathway proteins that require the signal recognition particle for translocation to the endoplasmic reticulum (ER). The vectors code for N-terminal and C-terminal affinity tags including 3 × FLAG and Twin-Strep, which represent tags compatible with efficient translocation to the ER as well as with purification under mild conditions that preserve protein structure and function. As a model, we used our system to express and purify the engineered high-affinity immunoglobulin gamma Fc receptor I (CD64) in complex with its gamma subunit (γ-chain). We demonstrate that CD64 expressed in complex with the γ-chain is functional in immunoglobulin G (IgG) binding. The sedimentation of CD64 in complex with IgG suggests individual CD64/IgG complexes in addition to formation of high-molecular weight complexes. In summary, our vectors can be used as a tool for expression of membrane proteins, other secretory pathway proteins and their protein complexes.
Collapse
Affiliation(s)
- Le T M Le
- Stereology and EM Laboratory, Department of Clinical Medicine, Aarhus University, 8000, Aarhus C, Denmark
| | - Jens R Nyengaard
- Stereology and EM Laboratory, Department of Clinical Medicine, Aarhus University, 8000, Aarhus C, Denmark
- Core Center for Molecular Morphology, Department of Clinical Medicine, Aarhus University Hospital, 8000, Aarhus C, Denmark
- Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University, 8000, Aarhus C, Denmark
| | - Monika M Golas
- Department of Biomedicine, Aarhus University, Wilhelm Meyers Allé 3, Building 1233/1234, 8000, Aarhus C, Denmark
- Department of Human Genetics, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Bjoern Sander
- Stereology and EM Laboratory, Department of Clinical Medicine, Aarhus University, 8000, Aarhus C, Denmark.
- Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University, 8000, Aarhus C, Denmark.
- Institute of Pathology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| |
Collapse
|
5
|
Swisher JFA, Feldman GM. The many faces of FcγRI: implications for therapeutic antibody function. Immunol Rev 2016; 268:160-74. [PMID: 26497519 DOI: 10.1111/imr.12334] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Fcγ receptor I (FcγRI or CD64) is the sole human Fc receptor with high affinity for monovalent IgG. While it contains an immunoreceptor tyrosine-based activation motif in its cytoplasmic domain, binding of FcγRI can result in a complex array of activating and inhibitory outcomes. For instance, binding of monomeric IgG provides a low-intensity tonic signal through FcγRI that is necessary for full interferon γ receptor signaling in the same cell. Interaction of FcγRI with larger high-avidity complexes can result in phagocytosis, the generation of reactive oxygen species, as well as the synthesis and release of inflammatory cytokines. However, numerous reports also document potent anti-inflammatory effects brought about by FcγRI engagement with immune complexes such as the inhibition of IFNγ and TLR4 signaling, and secretion of interleukin-10. This has led to conflicting hypotheses regarding the function of FcγRI, especially with regard to its role in the efficacy of several therapeutic monoclonal antibodies. While many of these issues are still unclear, continued characterization of the regulation and context dependence of FcγRI function, as well as the molecular mechanisms responsible for these various outcomes, will improve our understanding of FcγRI biology as well as the therapeutic strategies designed to harness or constrain its actions.
Collapse
Affiliation(s)
- Jennifer F A Swisher
- Laboratory of Immunobiology, Division of Biotechnology Research and Review IV, Office of Biotechnology Products, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA
| | - Gerald M Feldman
- Laboratory of Immunobiology, Division of Biotechnology Research and Review IV, Office of Biotechnology Products, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA
| |
Collapse
|
6
|
Chenoweth AM, Trist HM, Tan PS, Wines BD, Hogarth PM. The high-affinity receptor for IgG, FcγRI, of humans and non-human primates. Immunol Rev 2015; 268:175-91. [DOI: 10.1111/imr.12366] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Alicia M. Chenoweth
- Centre for Biomedicine; Burnet Institute; Melbourne Vic. Australia
- Department of Immunology; Monash University; Melbourne Vic. Australia
| | - Halina M. Trist
- Centre for Biomedicine; Burnet Institute; Melbourne Vic. Australia
| | - Peck-Szee Tan
- Centre for Biomedicine; Burnet Institute; Melbourne Vic. Australia
| | - Bruce D. Wines
- Centre for Biomedicine; Burnet Institute; Melbourne Vic. Australia
- Department of Immunology; Monash University; Melbourne Vic. Australia
- Department of Pathology; University of Melbourne; Melbourne Vic. Australia
| | - P. Mark Hogarth
- Centre for Biomedicine; Burnet Institute; Melbourne Vic. Australia
- Department of Immunology; Monash University; Melbourne Vic. Australia
- Department of Pathology; University of Melbourne; Melbourne Vic. Australia
| |
Collapse
|
7
|
Efficient expression of recombinant soluble human FcγRI in mammalian cells and its characterization. Protein Expr Purif 2012; 82:155-61. [DOI: 10.1016/j.pep.2011.12.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 12/14/2011] [Accepted: 12/20/2011] [Indexed: 11/18/2022]
|
8
|
Jie HB, Yim D, Kim YB. Porcine Fc gammaRIII isoforms are generated by alternative splicing. Mol Immunol 2009; 46:1189-94. [PMID: 19124157 DOI: 10.1016/j.molimm.2008.11.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Revised: 11/09/2008] [Accepted: 11/12/2008] [Indexed: 11/30/2022]
Abstract
The Fc gammaRIII plays an essential role in antibody-mediating effector functions of immune cells. Here, we report that transcripts encoding porcine Fc gammaRIII isoforms are generated by alternative splicing. Fc gammaRIII a.1 is expressed on the cell surface while Fc gammaRIII a.2 is secreted from the transfected cells due to a partial deletion of the transmembrane domain. Interestingly, a putative soluble Fc gammaRIII (sCD16) is detected in circulating plasma. Both Fc gammaRIII a.2 and sCD16 exhibit a similar molecular mass (approximately 35 kDa) and contain the extracellular D2 domains that are structurally intact. Despite the D2 domain deletion, Fc gammaRIII a.3 associates with Fc gammaRIII a.1. Hence, these results suggest one possibility that three Fc gammaRIII isoforms differentially modulate Fc gammaRIII-mediated immune responses in the porcine system. Furthermore, we demonstrate that a cytolytic triggering G7 monoclonal antibody recognizes the D2 domain that is responsible for interacting with the immune complexes and subsequent activations of porcine innate immune cells. This result suggests that the D2 domain is a target region to develop therapeutic antibodies that regulate the FcR-mediated immune responses.
Collapse
Affiliation(s)
- Hyun-Bae Jie
- Asthma Research, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 49229-3039, USA
| | | | | |
Collapse
|
9
|
Davis RS, Ehrhardt GRA, Leu CM, Hirano M, Cooper MD. An extended family of Fc receptor relatives. Eur J Immunol 2005; 35:674-80. [PMID: 15688344 DOI: 10.1002/eji.200425886] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A surprising number of Fc receptor (FcR) relatives have been recognized recently with the potential capacity to modulate innate and adaptive immune responses. The six human FcR homologs (FcRH1-6), which belong to a phylogenetically conserved gene family, have variable numbers of extracellular immunoglobulin domains of five different subtypes. FcRH immunoregulatory potential is implicated by the presence of consensus tyrosine-based activation or inhibition motifs in their cytoplasmic tails. All but one of these new receptors, FcRH6, are expressed on B cells at different stages in differentiation. Their ligands, function, and prospective roles as diagnostic B cell markers and therapeutic targets are topics of intense interest.
Collapse
Affiliation(s)
- Randall S Davis
- Division of Developmental and Clinical Immunology, University of Alabama, Birmingham, USA
| | | | | | | | | |
Collapse
|
10
|
Davis RS, Dennis G, Odom MR, Gibson AW, Kimberly RP, Burrows PD, Cooper MD. Fc receptor homologs: newest members of a remarkably diverse Fc receptor gene family. Immunol Rev 2002; 190:123-36. [PMID: 12493010 DOI: 10.1034/j.1600-065x.2002.19009.x] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Newfound relatives of the classical Fc receptors (FcR) have been provisionally named the Fc receptor homologs (FcRH). The recent identification of eight human and six mouse FcRH genes substantially increases the size and functional potential of the FcR family. The extended family of FcR and FcRH genes spans approximately 15 Mb of the human chromosome 1q21-23 region, whereas in mice this family is split between chromosomes 1 and 3. The FcRH genes encode molecules with variable combinations of five subtypes of immunoglobulin (Ig) domains. The presence of a conserved sequence motif in one Ig domain subtype implies Ig Fc binding capability for many FcRH family members that are preferentially expressed by B lineage cells. In addition, most FcRH family members have consensus tyrosine-based activating and inhibitory motifs in their cytoplasmic domains, while the others lack features typical of transmembrane receptors. The FcRH family members, like the classical FcRs, come in multiple isoforms and allelic variations. The unique individual and polymorphic properties of the FcR/FcRH members indicate a remarkably diverse Fc receptor gene family with immunoregulatory function.
Collapse
Affiliation(s)
- Randall S Davis
- Division of Hematology/Oncology, University of Alabama at Birmingham, AL 35294, USA
| | | | | | | | | | | | | |
Collapse
|
11
|
Affiliation(s)
- B K Flesch
- Institute of Transfusion Medicine, Christian Albrechts University of Kiel, Germany.
| | | |
Collapse
|
12
|
|
13
|
van Vugt MJ, Reefman E, Zeelenberg I, Boonen G, Leusen JH, van de Winkel JG. The alternatively spliced CD64 transcript FcgammaRIb2 does not specify a surface-expressed isoform. Eur J Immunol 1999; 29:143-9. [PMID: 9933095 DOI: 10.1002/(sici)1521-4141(199901)29:01<143::aid-immu143>3.0.co;2-#] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Three highly homologous genes (A, B and C) and six transcripts have been identified for the class I human IgG receptor (CD64). The hFcgammaRIa1 isoform encodes the prototypic high-affinity receptor for IgG. The alternatively spliced hFcgammaRIb2 transcript was postulated to exist as a second surface-expressed CD64 isoform on myeloid cells. In this report we assessed this proposed role for hFcgammaRIb2 in detail. As CD64 monoclonal antibodies might not recognize hFcgammaRIb2, we tagged the receptor with an hemagglutinin tag and transfected hFcgammaRIb2tag in the presence of FcR gamma-chain into IIA1.6 cells. Both transcript and protein of hFcgammaRIb2tag were clearly present in transfectants. However, in contrast to the (control) hFcgammaRIa1tag, no surface expression of hFcgammaRIb2tag was detectable with a tag-specific monoclonal antibody. Confocal scan laser microscopy revealed hFcgammaRIb2tag to be retained in the endoplasmic reticulum, resulting in absent plasma membrane expression. These results show hFcgammaRIb2 neither to be surface expressed, nor to represent a separate CD64 isoform. This finding, furthermore, implicates that other FcR transcripts defined at the mRNA level may not represent true FcR isoforms either.
Collapse
Affiliation(s)
- M J van Vugt
- Department of Immunology, University Hospital Utrecht, The Netherlands
| | | | | | | | | | | |
Collapse
|
14
|
Ernst LK, Duchemin AM, Miller KL, Anderson CL. Molecular characterization of six variant Fcgamma receptor class I (CD64) transcripts. Mol Immunol 1998; 35:943-54. [PMID: 9881690 DOI: 10.1016/s0161-5890(98)00079-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In humans, three distinct but closely related classes of receptors that bind the Fc portion of IgG (FcgammaRI, II and III) have been identified. FcgammaRI can bind monomeric IgG with high affinity and has a unique third extracellular domain (EC3). Three very similar genes have been characterized for FcgammaRI (A, B, C). Although the sequences are remarkably similar, a number of coding-region differences discriminate between the genes and amongst their transcripts. Six distinct FcgammaRI transcripts were analysed. Three transcripts, one from each gene, contain all six exons. Only the gene A transcript appears to encode a bona fide high affinity receptor, a three Ig-domain membrane spanning receptor that can bind monomeric IgG. Stop codons in the EC3 domains of the gene B and gene C isoforms would be predicted to generate secreted receptors. Three transcripts are alternatively spliced isoforms, one from gene A and two from gene B. One gene B transcript encodes a two Ig-domain transmembrane receptor which has structural characteristics of a low affinity FcgammaR.
Collapse
Affiliation(s)
- L K Ernst
- Department of Pathology, University of Pittsburgh School of Medicine and the University of Pittsburgh Cancer Institute, PA, USA
| | | | | | | |
Collapse
|
15
|
Van Vugt MJ, Van den Herik-Oudijk IE, Van de Winkel JG. FcgammaRIa-gamma-chain complexes trigger antibody-dependent cell-mediated cytotoxicity (ADCC) in CD5+ B cell/macrophage IIA1.6 cells. Clin Exp Immunol 1998; 113:415-22. [PMID: 9737671 PMCID: PMC1905059 DOI: 10.1046/j.1365-2249.1998.00666.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Most receptors for immunoglobulins exist as multi-subunit complexes, with unique ligand binding alpha-chains, combined with accessory signalling (gamma-, beta-, or zeta-) chains. The myeloid class I receptor for IgG (FcgammaRIa) has been shown to be dependent on the FcR gamma-chain for surface expression in vivo. In this study we assess the capacity of FcgammaRIa-gamma-chain complexes expressed in IIA1.6 cells to trigger phagocytosis and ADCC. An intact immunoreceptor tyrosine-based activation motif (ITAM) signalling motif proved essential for triggering of biological function via the FcgammaRIa receptor complex. Both the FcR gamma-chain and the FcgammaRIIa-ITAM proved active in directing phagocytosis of Staphylococcus aureus and ADCC of erythrocytes, triggered by the FcgammaRIa complex. The capacity of FcgammaRIa to trigger phagocytic and cytolytic activity by IIA1.6 cells, both considered 'professional phagocyte' functions, motivated us to re-evaluate the cell lineage and developmental stage of IIA1.6 cells. Although originally described as mouse B lymphocytes, the IIA1.6 cells proved positive for non-specific esterase activity and expressed the CD5 antigen. These combined characteristics place the IIA1.6 cells within a unique CD5+ B cell/macrophage lineage, optimally suited for cell biological analyses of phagocyte receptors.
Collapse
Affiliation(s)
- M J Van Vugt
- Department of Immunology, University Hospital Utrecht, The Netherlands
| | | | | |
Collapse
|
16
|
Foss FM, Saleh MN, Krueger JG, Nichols JC, Murphy JR. Diphtheria toxin fusion proteins. Curr Top Microbiol Immunol 1998; 234:63-81. [PMID: 9670613 DOI: 10.1007/978-3-642-72153-3_5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- F M Foss
- Boston University Medical Center, MA 02118, USA
| | | | | | | | | |
Collapse
|
17
|
Toyabe S, Kuwano Y, Takeda K, Uchiyama M, Abo T. IgA nephropathy-specific expression of the IgA Fc receptors (CD89) on blood phagocytic cells. Clin Exp Immunol 1997; 110:226-32. [PMID: 9367406 PMCID: PMC2265504 DOI: 10.1111/j.1365-2249.1997.tb08321.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We analysed the biochemical features of receptors for the Fc-region of IgA (Fc alphaR, CD89) on blood monocytes and granulocytes of patients with IgA nephropathy (IgAN). Fc alphaR on monocytes of IgAN were found to have a higher Mr (60-80 kD) than those of control monocytes (50-75 kD) and granulocytes (55-75 kD) in both IgAN and controls as shown by immunoprecipitation analysis. Removal of N-linked carbohydrates from Fc alphaR on monocytes of IgAN revealed a 32-36 kD protein core, the Mr of which was still higher than that of controls (28-32 kD). When Fc alphaR transcripts were analysed by reverse-transcription-PCR, only one prominent band was visualized in PCR products from IgAN monocytes. Since the results thus far show that IgAN monocytes express Fc alphaR protein and mRNA differently from granulocytes and control monocytes, PCR products were then cloned and sequenced. The predominant band in PCR products from IgAN monocytes was identical to that of the Fc alphaR a.1 transcript, and an additional 10 transcripts containing five novel transcripts were obtained from granulocytes and control monocytes. In three transcripts, we found an insertion sequence between the S2 and EC1 domains, suggesting the existence of a new exon. These results suggest a predominant usage of Fc alphaR a.1 among various transcripts of Fc alphaR in IgAN monocytes.
Collapse
Affiliation(s)
- S Toyabe
- Department of Immunology, Niigata University School of Medicine, Japan
| | | | | | | | | |
Collapse
|
18
|
Fodor E, Feren A, Jones A. Isolation and genomic analysis of the rat polymeric immunoglobulin receptor gene terminal domain and transcriptional control region. DNA Cell Biol 1997; 16:215-25. [PMID: 9052742 DOI: 10.1089/dna.1997.16.215] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The polymeric immunoglobulin receptor (pIgR) transports IgA and IgM across secretory epithelial cells and is essential in external immunity maintenance. We report here the structural characterization of the single-copy rat gene distributed over 30 kb of chromosomal DNA and analysis of its transcriptional control region. RNA sequencing and genomic analysis show a 5' terminal region originates at a major (+1) and a minor site producing an unusual 124-bp nontranslated exon I separated from a small 96-bp initiator ATG coding exon II by a 7.5-kb intron. The pIgR 5' region comprises a structured promoter with abundant helix-loop-helix (bHLH) cis elements positioned within an equivalent internal -70, -290, -528, and three centered at -745. The three latter bHLH elements each occur within 30-bp repeats at -690 to -780. Transient expression assays show a 1.3-kb 5' region is sufficient to drive expression in rat primary hepatocyte monolayer cultures, transformed human hepatic (HepG2) cells, and a mammary epithelial tumor cell line MCF-7, but is inactive in the rodent fibroblast 3T3 cell line. A minimal transcriptional promoter domain was deduced from sequentially deleted vectors revealing a +40 to -922 sequence to be sufficient for full activity. Further deletions within this region yield incremental losses in cis activity, indicating that multiple subregions comprise an extended transcriptional control region.
Collapse
Affiliation(s)
- E Fodor
- VA Medical Center and Department of Medicine, University of California, San Francisco 94121, USA
| | | | | |
Collapse
|
19
|
Knowles R, Keeping H, Nguyen K, Graeber T, D'Amico R, Simms H. Hypoxemia/reoxygenation down-regulates interleukin-8-stimulated bactericidal activity of polymorphonuclear neutrophil by differential regulation of CD16 and CD35 mRNA expression. Surgery 1996; 120:382-7; discussion 388. [PMID: 8751608 DOI: 10.1016/s0039-6060(96)80313-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND The purpose of this study was to determine the effects of hypoxemia/reoxygenation (H/R) on the regulation of interleukin-8 (IL-8)-stimulated human polymorphonuclear neutrophil (PMN) bactericidal activity. METHODS Venous human whole blood was rendered normoxic (Pvo2 saturation 60% to 80%), hypoxemic (Pvo2 saturation, less than 15%), or H/R (Pvo2 saturation more than 97%) by dialyzing the blood against a gas mixture of N2/H2/CO2 +/- 30% O2. Two hundred microliter aliquots from each study group were incubated with IL-8 (50 ng/ml) for 45 minutes before fluorescein isothiocyanate-conjugated mouse antihuman CD16 or CD35 antibodies were added. Bactericidal activity was measured with the release of 51Cr from labeled bacteria at 1:1, 5:1, and 10:1 PMN-target ratios. Steady-state mRNA levels for CD16 and CD35 were quantified by Northern blot analyses. RESULTS H/R reduced PMN bactericidal activity compared with hypoxemic levels for staphylococcus aureus (48 +/- 5.6 versus 27 +/- 3.3) and Escherichia coli (58 +/- 7.1 versus 33 +/- 4.2). H/R reduced the surface expression of CD16 but not CD35 (mean channel fluorescence CD16, 610 +/- 70 versus 310 +/- 30 for hypoxemia versus H/R; p < 0.01). After H/R was performed, IL-8 decreased mRNA levels for CD16 but not for CD35 compared with levels seen during hypoxemia + IL-8. CONCLUSIONS H/R down-regulates IL-8-stimulated PMN bactericidal activity by decreasing steady-state mRNA levels and surface expression of CD16. PMN bactericidal capability after H/R + IL-8 is primarily complementary and not Fc gamma receptor dependent.
Collapse
Affiliation(s)
- R Knowles
- Department of Surgery, Brown University School of Medicine, Rhode Island Hospital, Providence 02903, USA
| | | | | | | | | | | |
Collapse
|
20
|
Heijnen IA, Van de Winkel JG. A human Fc gamma RI/CD64 transgenic model for in vivo analysis of (bispecific) antibody therapeutics. JOURNAL OF HEMATOTHERAPY 1995; 4:351-6. [PMID: 8581368 DOI: 10.1089/scd.1.1995.4.351] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The human high-affinity IgG receptor, hFc gamma RI (CD64), is exclusively expressed on myeloid cells, where it serves an important role as a (cytotoxic) trigger molecule. To establish an in vivo model for analysis of the role of hFc gamma RI in immunity, we developed a novel transgenic mouse model. The human Fc gamma RIA gene, with endogenous regulatory sequences, was used to generate two lines of transgenic FVB/N mice. Immunohistochemical and flow cytometric studies showed that hFc gamma RI expression was restricted to myeloid cells. Monocytes, macrophages, and polymorphonuclear neutrophils (PMN) expressed physiologic hFc gamma RI levels, whereas lymphocytes and mast cells lacked expression. Human Fc gamma RI expression was regulated in vivo by the cytokines IFN-gamma (exactly as in humans) and IL-10. The transgenic receptor proved functional and bound human tumor cells via anti-hFc gamma RI-based bispecific antibodies. hFc gamma RI could, furthermore, be efficiently targeted in vivo by CD64 antibodies. These data demonstrate that the hFc gamma RI transgenic mouse model closely parallels the situation in humans. This mouse model seems useful for in vivo evaluation of the therapeutic potential of novel bispecific reagents in tumor and infection models.
Collapse
Affiliation(s)
- I A Heijnen
- Department of Immunology, University Hospital Utrecht, The Netherlands
| | | |
Collapse
|
21
|
Harrison PT, Bjørkhaug L, Hutchinson MJ, Allen JM. The interaction between human Fc gamma RI and the gamma-chain is mediated solely via the 21 amino acid transmembrane domain of Fc gamma RI. Mol Membr Biol 1995; 12:309-12. [PMID: 8747275 DOI: 10.3109/09687689509072432] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We have established a biological assay to investigate the nature of the non-covalent interaction between two integral type I membrane proteins, Fc gamma RI and gamma-chain. Fc gamma RI, the human high affinity receptor for immunoglobulin G (IgG), is expressed on the surface of macrophages and monocytes and mediates a broad range of important immunological functions. Fc gamma RI relies on a functional interaction with a second integral type I membrane protein, gamma-chain, to mediate many of these functions. For example, Fc gamma RI can only mediate phagocytosis of IgG-coated particles in COS cells when co-expressed with gamma-chain. We have previously shown that the cytoplasmic domain of Fc gamma RI is not necessary for this functional interaction. In this study we have used the phagocytosis assay to investigate the role of the transmembrane region of Fc gamma RI in mediating this functional interaction with gamma-chain by using mutant and chimeric forms of the receptor. Three mutants, which introduce or remove charged residues from a conserved 10 amino acid stretch of amino acids in the proximal transmembrane region of Fc gamma RI, were able to mediate phagocytosis of IgG-coated particles. In contrast, two chimeric receptors, In which 21 of the amino acids in the distal transmembrane region of Fc gamma RI were replaced with the transmembrane region of the related receptors CD2 or LFA3, were expressed but failed to interact functionally with gamma-chain to mediate phagocytosis. Thus, these mutants demonstrate that the interaction between human Fc gamma RI and gamma-chain is mediated solely via these 21 amino acids in the transmembrane domain of Fc gamma RI.
Collapse
Affiliation(s)
- P T Harrison
- Division of Biochemistry and Molecular Biology, University of Glasgow, UK
| | | | | | | |
Collapse
|
22
|
Repp R, Valerius T, Wieland G, Becker W, Steininger H, Deo Y, Helm G, Gramatzki M, Van de Winkel JG, Lang N. G-CSF-stimulated PMN in immunotherapy of breast cancer with a bispecific antibody to Fc gamma RI and to HER-2/neu (MDX-210). JOURNAL OF HEMATOTHERAPY 1995; 4:415-21. [PMID: 8581378 DOI: 10.1089/scd.1.1995.4.415] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Myeloid cells can mediate tumor cell cytotoxicity via certain receptors for immunoglobulins. Among the different Fc receptors, the high-affinity IgG receptor (Fc gamma RI, CD64) is a promising trigger molecule because it is selectively expressed on effector cells, including monocytes/macrophages and granulocyte colony-stimulating factor (G-CSF)-primed neutrophils. In vitro, a bispecific antibody (BsAb) (MDX-210, constructed by chemically cross-linking F(ab') fragments of monoclonal antibody (mAb) 520C9 to HER-2/neu and F(ab') fragments of mAb 22 to Fc gamma RI) mediated effective lysis of HER-2/neu overexpressing breast cancer cell lines. HER-2/neu (c-erbB2) is overexpressed in approximately 30% of breast and ovarian carcinomas and is a target for immunotherapy in clinical trials. In vitro assays showed Fc gamma RI-positive neutrophils to constitute a major effector cell population during G-CSF therapy. Based on these preclinical data and a preceding study at Dartmouth (New Hampshire) with a single dose of MDX-210 alone, a combination of G-CSF and MDX-210 is tested in a phase I study in breast cancer patients. In this study, patients receiving G-CSF are treated with escalating single doses of MDX-210. This therapy was generally well tolerated by the treated patients, some of whom reacted with fever and short periods of chills, which were temporally related to elevated plasma levels of IL-6 and TNF-alpha. After MDX-210 application, a transient decrease in the total white blood count and absolute neutrophil count (ANC) was observed. During G-CSF application, isolated neutrophils were highly cytotoxic in the presence of MDX-210 in vitro. These data indicate a potential role for G-CSF and BsAb in immunotherapy.
Collapse
MESH Headings
- Antibodies, Bispecific/adverse effects
- Antibodies, Bispecific/immunology
- Antibodies, Bispecific/therapeutic use
- Antibodies, Monoclonal/adverse effects
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/therapeutic use
- Antibody Specificity
- Antibody-Dependent Cell Cytotoxicity
- Blood Cell Count/drug effects
- Breast Neoplasms/blood
- Breast Neoplasms/immunology
- Breast Neoplasms/therapy
- Burkitt Lymphoma/pathology
- Carcinoma, Squamous Cell/pathology
- Combined Modality Therapy
- Cytotoxicity, Immunologic/drug effects
- Female
- Glioma/pathology
- Granulocyte Colony-Stimulating Factor/adverse effects
- Granulocyte Colony-Stimulating Factor/pharmacology
- Granulocyte Colony-Stimulating Factor/therapeutic use
- Humans
- Immunologic Factors/adverse effects
- Immunologic Factors/pharmacology
- Immunologic Factors/therapeutic use
- Immunotherapy/adverse effects
- Immunotherapy/methods
- Interleukin-6/blood
- Leukopenia/chemically induced
- Neoplasm Proteins/immunology
- Neutrophils/drug effects
- Neutrophils/immunology
- Receptor, ErbB-2/immunology
- Receptors, IgG/immunology
- Tumor Cells, Cultured
- Tumor Necrosis Factor-alpha/analysis
Collapse
Affiliation(s)
- R Repp
- Department of Medicine III, University of Erlangen-Nürnberg, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
Human immunoglobulin G (IgG) Fc receptors are important in the materno-fetal relationship. Three classes of IgG Fc receptors are recognized which generate multiple isoforms, most of which are expressed in different cellular components of human placenta at different times during pregnancy. Although the distinct biological functions of Fc gamma R phenotypes expressed in human placenta are still unknown, recent data provide evidence for an important association between the Fc gamma R phenotype and transcytosis of IgG in the placenta. Selective transfer of maternal IgG across the placenta provides passive immunity to the fetus during the period when its own immune system is gaining protective potential. Furthermore, placenta-specific macrophages may contribute through Fc gamma R-mediated phagocytosis to the protection of the fetus from either infection or maternal immune attack against paternally inherited fetal antigens. Ontogeny and expression of various isoforms of Fc gamma R subtypes may be the key to the elucidation of the transport mechanism of maternal IgG to the fetus, in addition to the determination of the mechanisms of placental protection of the fetus against the maternal immune system.
Collapse
Affiliation(s)
- F Saji
- Department of Obstetrics and Gynecology, Osaka University Medical School, Japan
| | | | | |
Collapse
|
24
|
Markovic B, Wu ZH, Chesterman CN, Chong BH. Quantitation of Fc gamma RII mRNA in platelets and megakaryoblastic cell lines by a new method of in situ hybridization. J Immunol Methods 1994; 172:105-14. [PMID: 8207259 DOI: 10.1016/0022-1759(94)90383-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We have developed a highly sensitive and quantitative, non-isotopic method of in situ hybridization in which the level of probe binding to intracellular mRNA is determined using an ELISA based detection method. Highly purified cell preparations or cells from a cultured cell line are centrifuged into 96 well microtiter plates. The cells are fixed with formalin and pre-treated with Triton X-100 and Nonidet P40 before photobiotin labeled cDNA probes are applied. The biotin from the hybridization is detected using multiple applications of streptavidin and biotinylated alkaline phosphatase and then visualized by the p-NPP (p-nitrophenyl phosphate) conversion method. We have determined a number of the optimal parameters in the procedure including the effects of cell numbers per well, development times and standardization of data using ubiquitous beta-actin mRNA and poly-A+ RNA expression as controls. We have used the technique to study the level of expression of FcgR mRNA in platelets and precursors. We found that platelets and megakaryoblastic cell lines only express mRNA for Fc gamma RII. The presence of the Fc gamma RII molecules was confirmed by complementary studies using immunohistochemistry with specific monoclonal antibodies IV.3 and KB61.
Collapse
Affiliation(s)
- B Markovic
- Department of Haematology, University of New South Wales, Prince of Wales Hospital, Sydney, Australia
| | | | | | | |
Collapse
|
25
|
Kent SJ, Stent G, Sonza S, Hunter SD, Crowe SM. HIV-1 infection of monocyte-derived macrophages reduces Fc and complement receptor expression. Clin Exp Immunol 1994; 95:450-4. [PMID: 7907957 PMCID: PMC1535088 DOI: 10.1111/j.1365-2249.1994.tb07017.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Fc receptor (FcR) and complement receptor (CR) expression on HIV-infected monocyte-derived macrophages may be an important determinant of immune function. We studied the effects of HIV-1 infection of macrophages in vitro on FcR and CR expression. Macrophages were infected with HIV-1DV 7 days following isolation, and the expression of Fc gamma RI-III and CR3 were measured at intervals thereafter by flow cytometry. We found a reduction in receptor expression with the percentage of cells expressing FcRI 14 days post infection declining from 77% to 13%, FcRII fell from 96% to 85%, FcRIII from 45% to 9%, and CR3 from 91% to 67% 14 days following infection. As these receptors are important for macrophage function, their down-modulation may contribute to the pathogenesis of HIV-related disease.
Collapse
Affiliation(s)
- S J Kent
- AIDS Pathogenesis Research Unit, Macfarlane Burnet Centre for Medical Research, Fairfield, Australia
| | | | | | | | | |
Collapse
|
26
|
Brooks D, Ravetch JV. Fc receptor signaling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1994; 365:185-95. [PMID: 7887303 DOI: 10.1007/978-1-4899-0987-9_19] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- D Brooks
- Dewitt Wallace Research Laboratory, Sloan-Kettering Institute, New York, NY 10021
| | | |
Collapse
|
27
|
|
28
|
Affiliation(s)
- M D Hulett
- Austin Research Institute, Heidelberg, Australia
| | | |
Collapse
|
29
|
Duits AJ, Aarden LA, Ernst LK, Capel PJ, van de Winkel JG. Isotype-specific cross-linking of select human Fc gamma R isoforms triggers release of IL-6. Clin Exp Immunol 1993; 92:225-31. [PMID: 8485907 PMCID: PMC1554805 DOI: 10.1111/j.1365-2249.1993.tb03384.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Anti-CD3 MoAbs are widely used in T cell activation studies, and are effective in immunosuppressive therapy. We used a panel of mouse (m) anti-CD3 switch variant MoAbs of five different isotypes to study IL-6 release from accessory cells. Incubation of human (h) mononuclear cells with anti-CD3 MoAbs resulted in increased IL-6 levels with MoAbs of mIgG1 and mIgG2a isotypes, with no effect of mIgG2b or mIgA. This suggested involvement of IgG Fc receptors (Fc gamma R) in triggering IL-6 production. To evaluate the role of different Fc gamma R molecules individually we used a panel of hFc gamma R-transfected mouse fibroblasts, and Jurkat T cells as a model. IL-6 secretion by CD32 transfectants expressing the hFc gamma RIIa high-responder (HR) allelic form was triggered by mIgG1 anti-CD3 MoAb, with no effect of four other isotypes. None of the anti-CD3 MoAbs induced IL-6 secretion by CD32 transfectants expressing either a variant of this receptor, containing only a single intracellular amino acid (CT-), the hFc gamma RIIa low-responder (LR) allelic form, or hFc gamma RIIb1. hFc gamma RI (CD64) transfectants exhibited IL-6 production after incubation with mIgG2a anti-CD3 MoAb, and to a lesser extent with mIgG2b, and mIgG1 MoAb. Indirect involvement of T cells in triggering IL-6 secretion could be excluded by experiments in which transfectants were cultured with immobilized anti-CD3 MoAb. These data indicate that cross-linking of either hFc gamma RI, or hFc gamma RIIaHR by appropriate anti-CD3 MoAbs triggers IL-6 production of accessory cells, and not T cells. This may also take place in vivo during immunosuppressive therapy with anti-CD3 MoAbs, and related antibody-mediated immune responses.
Collapse
Affiliation(s)
- A J Duits
- Department of Immunology, University Hospital Utrecht, The Netherlands
| | | | | | | | | |
Collapse
|
30
|
van de Winkel JG, Capel PJ. Human IgG Fc receptor heterogeneity: molecular aspects and clinical implications. IMMUNOLOGY TODAY 1993; 14:215-21. [PMID: 8517920 DOI: 10.1016/0167-5699(93)90166-i] [Citation(s) in RCA: 511] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Receptors for the Fc domain of IgG (Fc gamma R) provide a critical link between specific humoral responses and the cellular branch of the immune system. When hFc gamma R interact with immunoglobulin, a variety of biological responses are triggered. These include phagocytosis, endocytosis, antibody-dependent cellular cytotoxicity (ADCC), release of inflammatory mediators, and enhancement of antigen presentation. In the last few years our understanding of the Fc gamma receptor structure has increased dramatically, due to the availability of monoclonal antibodies (mAb) and cDNA probes. Fc gamma R are members of the immunoglobulin superfamily and three main classes, hFc gamma RI, hFc gamma RII, and hFc gamma RIII are recognized in man generating at least 12 different isoforms. A further level of complexity is introduced by various genetic polymorphisms and, importantly, recent evidence points at the relevance of this Fc gamma R heterogeneity.
Collapse
|
31
|
The human low affinity immunoglobulin G Fc receptor IIC gene is a result of an unequal crossover event. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53181-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
32
|
de Wit TP, Suijkerbuijk RF, Capel PJ, van Kessel AG, van de Winkel JG. Assignment of three human high-affinity Fc gamma receptor I genes to chromosome 1, band q21.1. Immunogenetics 1993; 38:57-9. [PMID: 8462996 DOI: 10.1007/bf00216392] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- T P de Wit
- Dept. of Immunology, University Hospital Utrecht, The Netherlands
| | | | | | | | | |
Collapse
|
33
|
Symons DB, Clarkson CA. Genomic organisation and sequence of the extracellular domain exons of the bovine Fc gamma RI receptor, and evidence for restricted binding of ruminant IgG to U937 cells. Mol Immunol 1992; 29:1407-13. [PMID: 1406725 DOI: 10.1016/0161-5890(92)90178-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Southern blotting of bovine genomic DNA and hybridization with a human Fc gamma RI cDNA probe, p135, has identified a single copy of the bovine Fc gamma RI gene. A bovine genomic lymphocyte library in lambda EMBL3 was screened with probe p135. A positive lambda clone, 15.5.4, containing the three extracellular domain exons of Fc gamma RI, has been cloned, mapped and sequenced. Each extracellular domain is encoded within a single exon. All three domains are assigned to the C-2 set of the Ig superfamily with 58% identity between amino acid residues of bovine, human and mouse Fc gamma RI. Pairs of cysteine residues are conserved in each domain as potential sites for intra-chain disulphide bonding. Human monocytoid U937 cells were used as a model to test binding homology within the Fc gamma RI family. The binding of IgG isotypes to IFN-gamma stimulated U937 cells was determined by FACScan flow cytometry. U937 cell Fc gamma RI receptor does not bind bovine or ovine IgG isotypes. On the basis of these studies and by comparison of the Fc determinant region sequences of IgG, the introduction of species specificity in Fc gamma RI/IgG interaction by evolutionary drift is proposed.
Collapse
Affiliation(s)
- D B Symons
- Agricultural and Food Research Council, Institute of Animal Physiology and Genetics Research, Babraham, Cambridge, U.K
| | | |
Collapse
|
34
|
McKenzie SE, Keller MA, Cassel DL, Schreiber AD, Schwartz E, Surrey S, Rappaport EF. Characterization of the 5'-flanking transcriptional regulatory region of the human Fc gamma receptor gene, Fc gamma RIIA. Mol Immunol 1992; 29:1165-74. [PMID: 1382218 DOI: 10.1016/0161-5890(92)90052-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The human Fc gamma receptor gene Fc gamma RIIA is expressed in platelets, neutrophils, monocytes and macrophages. Understanding the regulation of expression of Fc gamma RIIA will enhance our knowledge of regulated gene expression and immune function in these cells. We cloned a 3.65 kb region of the 5' end of the Fc gamma RIIA gene and characterized 3.4 kb of previously unreported sequence of the 5'-flanking region. Primer extension studies and RNase protection analyses of mRNA from HEL, K562 and U937 cells revealed multiple transcription start sites. One transcription start site mapped to a 5'-untranslated (5'UT) exon approximately 1 kb 5' to the ATG translation initiation codon, while a second start site mapped near the ATG codon. Reverse transcription combined with PCR (RT-PCR) employing an oligonucleotide in the putative 5'UT exon and an antisense oligonucleotide in the translated region yielded products which confirm that transcription starts in this 5'UT exon 881 bp upstream of the ATG codon. Sequence analysis of the RT-PCR products showed two related RNA splice products which use alternative 3'-consensus AG splice acceptor sites. Fc gamma RIIA mRNA thus has three distinct potential 5'UT regions, two alternatively spliced forms from the start site in the 5'UT exon and the third from the start site near the ATG codon. Comparisons of the human Fc gamma RIIA 5'-flanking region with human Fc gamma RI and mouse Fc gamma RII beta genes as well as with other genes expressed in megakaryocytes, neutrophils and monocytes reveal structural similarities and shared promoter elements.
Collapse
Affiliation(s)
- S E McKenzie
- Division of Hematology, Children's Hospital of Philadelphia, PA 19104
| | | | | | | | | | | | | |
Collapse
|
35
|
van Schie RC, Verstraten HG, Tax WJ, van den Berkmortel FW, van de Winkel JG, de Mulder PH. Effect of rIFN-gamma on antibody-mediated cytotoxicity via human monocyte IgG Fc receptor II (CD32). Scand J Immunol 1992; 36:385-93. [PMID: 1387726 DOI: 10.1111/j.1365-3083.1992.tb02952.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Human monocytes and macrophages express an isoform of IgG Fc receptor II (Fc gamma RII), Fc gamma RIIa. Two allotypic variants of this receptor could be distinguished with respect to their ability to bind murine (m)IgG1 complexes either strongly or weakly, defined as high-responder (HR) and low-responder (LR), respectively. We investigated the effect of recombinant (r)IFN-gamma on the ability of freshly isolated monocytes, and those cultured for 40 h and 9 days, to mediate antibody-dependent cell-mediated cytotoxicity (ADCC). Using human erythrocytes (E) sensitized with mIgG1 as target cells, Fc gamma RII was studied selectively. Cells which had been cultured for 40 h exhibit a significantly decreased Fc gamma RII expression, and Fc gamma RII-mediated ADCC activity as compared with freshly isolated monocytes. Co-culture with rIFN-gamma (40 h) reversed this decrease. Short-term rIFN-gamma-cultured cells, and fresh cells express similar numbers of Fc gamma RII, and exhibit comparable Fc gamma RII-mediated ADCC activity. Phagocytic activity was not affected. Prolonged culture of monocytes for 9 days, co-cultured with rIFN-gamma either from day 0 or from day 7, did not affect expression or functional activity of Fc gamma RII. Furthermore, the effects were observed in both HR and LR individuals. Our results show that rIFN-gamma has strong effects on Fc gamma RII-mediated responses specifically during the early stages of monocyte maturation, most likely by affecting receptor expression levels.
Collapse
Affiliation(s)
- R C van Schie
- Department of Internal Medicine, University Hospital Nijmegen, The Netherlands
| | | | | | | | | | | |
Collapse
|
36
|
Ernst L, van de Winkel J, Chiu I, Anderson C. Three genes for the human high affinity Fc receptor for IgG (Fc gamma RI) encode four distinct transcription products. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)49591-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|