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Santos-López J, de la Paz K, Fernández FJ, Vega MC. Structural biology of complement receptors. Front Immunol 2023; 14:1239146. [PMID: 37753090 PMCID: PMC10518620 DOI: 10.3389/fimmu.2023.1239146] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 08/16/2023] [Indexed: 09/28/2023] Open
Abstract
The complement system plays crucial roles in a wide breadth of immune and inflammatory processes and is frequently cited as an etiological or aggravating factor in many human diseases, from asthma to cancer. Complement receptors encompass at least eight proteins from four structural classes, orchestrating complement-mediated humoral and cellular effector responses and coordinating the complex cross-talk between innate and adaptive immunity. The progressive increase in understanding of the structural features of the main complement factors, activated proteolytic fragments, and their assemblies have spurred a renewed interest in deciphering their receptor complexes. In this review, we describe what is currently known about the structural biology of the complement receptors and their complexes with natural agonists and pharmacological antagonists. We highlight the fundamental concepts and the gray areas where issues and problems have been identified, including current research gaps. We seek to offer guidance into the structural biology of the complement system as structural information underlies fundamental and therapeutic research endeavors. Finally, we also indicate what we believe are potential developments in the field.
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Affiliation(s)
- Jorge Santos-López
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Karla de la Paz
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- Research & Development, Abvance Biotech SL, Madrid, Spain
| | | | - M. Cristina Vega
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
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2
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Stögerer T, Silva-Barrios S, Carmona-Pérez L, Swaminathan S, Mai LT, Leroux LP, Jaramillo M, Descoteaux A, Stäger S. Leishmania donovani Exploits Tunneling Nanotubes for Dissemination and Propagation of B Cell Activation. Microbiol Spectr 2023; 11:e0509622. [PMID: 37404188 PMCID: PMC10434010 DOI: 10.1128/spectrum.05096-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 06/08/2023] [Indexed: 07/06/2023] Open
Abstract
Polyclonal B cell activation and the resulting hypergammaglobulinemia are a detrimental consequence of visceral leishmaniasis (VL); however, the mechanisms underlying this excessive production of nonprotective antibodies are still poorly understood. Here, we show that a causative agent of VL, Leishmania donovani, induces CD21-dependent formation of tunneling nanotubule (TNT)-like protrusions in B cells. These intercellular connections are used by the parasite to disseminate among cells and propagate B cell activation, and close contact both among the cells and between B cells and parasites is required to achieve this activation. Direct contact between cells and parasites is also observed in vivo, as L. donovani can be detected in the splenic B cell area as early as 14 days postinfection. Interestingly, Leishmania parasites can also glide from macrophages to B cells via TNT-like protrusions. Taken together, our results suggest that, during in vivo infection, B cells may acquire L. donovani from macrophages via TNT-like protrusions, and these connections are subsequently exploited by the parasite to disseminate among B cells, thus propagating B cell activation and ultimately leading to polyclonal B cell activation. IMPORTANCE Leishmania donovani is a causative agent of visceral leishmaniasis, a potentially lethal disease characterized by strong B cell activation and the subsequent excessive production of nonprotective antibodies, which are known to worsen the disease. How Leishmania activates B cells is still unknown, particularly because this parasite mostly resides inside macrophages and would not have access to B cells during infection. In this study, we describe for the first time how the protozoan parasite Leishmania donovani induces and exploits the formation of protrusions that connect B lymphocytes with each other or with macrophages and glides on these structures from one cell to another. In this way, B cells can acquire Leishmania from macrophages and become activated upon contact with the parasites. This activation will then lead to antibody production. These findings provide an explanation for how the parasite may propagate B cell activation during infection.
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Affiliation(s)
- Tanja Stögerer
- Institut National de la Recherche Scientifique (INRS) – Centre Armand-Frappier Santé Biotechnologie and Infectiopôle INRS, Laval, Quebec, Canada
| | - Sasha Silva-Barrios
- Institut National de la Recherche Scientifique (INRS) – Centre Armand-Frappier Santé Biotechnologie and Infectiopôle INRS, Laval, Quebec, Canada
| | - Liseth Carmona-Pérez
- Institut National de la Recherche Scientifique (INRS) – Centre Armand-Frappier Santé Biotechnologie and Infectiopôle INRS, Laval, Quebec, Canada
| | - Sharada Swaminathan
- Institut National de la Recherche Scientifique (INRS) – Centre Armand-Frappier Santé Biotechnologie and Infectiopôle INRS, Laval, Quebec, Canada
| | - Linh Thuy Mai
- Institut National de la Recherche Scientifique (INRS) – Centre Armand-Frappier Santé Biotechnologie and Infectiopôle INRS, Laval, Quebec, Canada
| | - Louis-Philippe Leroux
- Institut National de la Recherche Scientifique (INRS) – Centre Armand-Frappier Santé Biotechnologie and Infectiopôle INRS, Laval, Quebec, Canada
| | - Maritza Jaramillo
- Institut National de la Recherche Scientifique (INRS) – Centre Armand-Frappier Santé Biotechnologie and Infectiopôle INRS, Laval, Quebec, Canada
| | - Albert Descoteaux
- Institut National de la Recherche Scientifique (INRS) – Centre Armand-Frappier Santé Biotechnologie and Infectiopôle INRS, Laval, Quebec, Canada
| | - Simona Stäger
- Institut National de la Recherche Scientifique (INRS) – Centre Armand-Frappier Santé Biotechnologie and Infectiopôle INRS, Laval, Quebec, Canada
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Shi M, Huang R, Du F, Pei Y, Liao L, Zhu Z, Wang Y. RNA-seq profiles from grass carp tissues after reovirus (GCRV) infection based on singular and modular enrichment analyses. Mol Immunol 2014; 61:44-53. [PMID: 24865419 DOI: 10.1016/j.molimm.2014.05.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 04/09/2014] [Accepted: 05/07/2014] [Indexed: 11/29/2022]
Abstract
Hemorrhagic disease of the grass carp, Ctenopharyngodon idella, is a fatal disease in fingerlings and yearlings caused by a reovirus, GCRV. RNA-seq data from four diseased grass carp tissues (gill, intestine, liver and spleen) were obtained at 2h before and six times after (2h, 24h, 48h, 72h, 96h and 120h) GCRV challenge. A total of 7.25±0.18 million (M) clean reads and 3.53±0.37M unique reads were obtained per RNA-seq analysis. Compared with controls, there were 9060 unique differentially expressed genes (DEGs) in the four tissues at the six time points post-GCRV challenge. Hierarchical clustering analysis of the DEGs showed that the data from the six time points fell into three branches: 2h, 24h/48h, and 72h/96h/120h. Singular (SEA) and modular enrichment analyses of DEGs per RNA-seq dataset were performed based on gene ontology. The results showed that immune responses occurred in all four tissues, indicating that GCRV probably does not target any tissue specifically. Moreover, during the course of disease, disturbances were observed in lipid and carbohydrate metabolism in each of the organs. SEA of DEGs based on the Kyoto Encyclopedia of Genes and Genomes database was also performed, and this indicated that the complement system and cellular immunity played an important role during the course of hemorrhagic disease. The qPCR of pooled samples of duplicate challenge experiment were used to confirm our RNA-seq approach.
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Affiliation(s)
- Mijuan Shi
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Rong Huang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Fukuan Du
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Yongyan Pei
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Lanjie Liao
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Zuoyan Zhu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Yaping Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
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Implications of the parent-into-F1 model for human lupus pathogenesis: roles for cytotoxic T lymphocytes and viral pathogens. Curr Opin Rheumatol 2010; 22:493-8. [PMID: 20485174 DOI: 10.1097/bor.0b013e32833b0174] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
PURPOSE OF REVIEW The central role of CD4 T cells in lupus pathogenesis is well recognized; however, the mechanism by which CD4 T cells lose tolerance and promote humoral autoimmunity remains unclear. This review examines mechanisms elucidated in the parent-into-F1 model of lupus and their possible parallels in human lupus pathogenesis. RECENT FINDINGS In the parent-into-F1 model, lupus results from the transfer of normal, foreign reactive CD4 T cells targeted to intrinsically normal F1 B cells. Transfer of normal CD8 T cells prevents lupus, whereas transfer of CD8 T cells with killing defects does not but is correctable with additional in-vivo enhancement of CD8 cytotoxic T lymphocyte (CTL) function. The parent-into-F1 model has two major similarities to Epstein-Barr virus infection: CD4 T-cell-driven polyclonal B-cell hyperactivity and a critical dependence on CD8 CTL for elimination of activated B cells. These similarities are discussed in relation to human lupus pathogenesis. SUMMARY Work in the parent-into-F1 model supports the idea that lupus may result from defective CD8 T-cell function and that therapeutic enhancement of CD8 effectors with selective targeting to autoreactive B cells may be beneficial. Despite strong evidence linking Epstein-Barr virus infection with human lupus, the exact nature of this link requires further study.
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Erdei A, Isaák A, Török K, Sándor N, Kremlitzka M, Prechl J, Bajtay Z. Expression and role of CR1 and CR2 on B and T lymphocytes under physiological and autoimmune conditions. Mol Immunol 2009; 46:2767-73. [PMID: 19559484 DOI: 10.1016/j.molimm.2009.05.181] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Accepted: 05/29/2009] [Indexed: 11/17/2022]
Abstract
The involvement of complement in the development and regulation of antibody responses under both healthy and pathological conditions is known for long. Unravelling the molecular mechanisms underlying the events however is still in progress. This review focuses on the role of complement receptors CR1 (CD35) and CR2 (CD21) expressed on T and B cells. Alteration in the expression and function of these receptors may contribute to the initiation and maintenance of immune complex mediated autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. Recent data regarding complement receptor expression on T lymphocytes and on memory B cells are also discussed.
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Affiliation(s)
- Anna Erdei
- Department of Immunology, Biological Institute, Eötvös Loránd University, Budapest, Hungary.
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6
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Kulik L, Marchbank KJ, Lyubchenko T, Kuhn KA, Liubchenko GA, Haluszczak C, Gipson MG, Gibson MG, Boackle SA, Holers VM. Intrinsic B cell hypo-responsiveness in mice prematurely expressing human CR2/CD21 during B cell development. Eur J Immunol 2007; 37:623-33. [PMID: 17301948 DOI: 10.1002/eji.200636248] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We previously reported that human CR2 (hCR2) prematurely expressed under a murine Vlambda2 promoter/Vlambda2-4 enhancer minigene during the CD43+ CD25- late pro-B cell stage of development results in peripheral B cells with impaired responses to immunization with T-dependent antigens. Herein, we show that hCR2 transgenic (Tg) mice also demonstrate a severe defect in T-independent antigen responses and are substantially protected from clinical arthritis, synovitis and cartilage/bone destruction in a collagen-induced arthritis model. This outcome is found despite the apparently normal development of autoreactive T cells with equivalent cytokine and proliferative responses to antigen when compared to non-Tg control mice. These data suggest the presence of an intrinsic B cell defect in the hCR2 Tg mice. We also show that an hCR2-dependent Ca2+ influx can be generated in both developing and mature Tg B cells, but with different rates of decay as compared to control wild-type (WT) mice. In addition, although analysis of tyrosine-phosphorylated proteins in WT and Tg B cells following B cell receptor (BCR)-induced activation revealed the presence of distinctly different phosphorylation patterns, no differences were identified in several candidate protein targets. Overall, these data suggest that premature hCR2 expression and the consequences thereof during B cell development intrinsically alters the way mature B cells develop and subsequently respond to antigen through the BCR signaling complex.
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MESH Headings
- Animals
- Antibody Formation/genetics
- Arthritis, Experimental/genetics
- Arthritis, Experimental/immunology
- B-Lymphocytes/cytology
- B-Lymphocytes/immunology
- B-Lymphocytes/metabolism
- Cell Differentiation/immunology
- Humans
- Lymphocyte Activation/genetics
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Transgenic
- Receptors, Antigen, B-Cell/physiology
- Receptors, Complement 3d/biosynthesis
- Receptors, Complement 3d/genetics
- Receptors, Complement 3d/immunology
- Signal Transduction/genetics
- Signal Transduction/immunology
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Affiliation(s)
- Liudmila Kulik
- Department of Medicine and Immunology, UCHSC, Denver, CO 80262, USA
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Ding H, Prodinger WM, Kopeèek J. Two-step fluorescence screening of CD21-binding peptides with one-bead one-compound library and investigation of binding properties of N-(2-hydroxypropyl)methacrylamide copolymer-peptide conjugates. Biomacromolecules 2007; 7:3037-46. [PMID: 17096529 PMCID: PMC2536624 DOI: 10.1021/bm060508f] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Using the one-bead one-compound (OBOC) combinatorial method, four heptapeptide ligands of CD21 receptor, a cell surface marker of malignant B cell lymphoma, were identified with an innovative two-step fluorescence screening method to overcome the limitation caused by autofluorescence of TentaGel resin. The binding affinities of selected peptides, YILIHRN (B1), PTLDPLP (B2), and LVLLTRE (B3), were in the micromolar region as determined by a fluorescence quenching assay. Peptide B1 was conjugated to N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer via spacers of different lengths, composed of one to four repeats of the 8-amino-3,6-dioxaoctanoic acid (A) group. The evaluation of the biorecognizability of HPMA copolymer-B1 conjugates by the CD21 receptor revealed that increasing the number of repeats of A in the spacer from one to three resulted in continuous improvements in the biorecognition by the CD21 receptor; the increase from three to four repeats showed no significant effect. This work showed the potential of the OBOC combinatorial approach to select peptide ligands as targeting moieties for CD21 specific polymeric drug carriers.
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Affiliation(s)
| | | | - Jindøich Kopeèek
- *To whom correspondence should be addressed. Phone: (801) 581-7211. Fax: (801) 581-7848. E-mail:
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Abstract
Events that occur in rheumatoid arthritis synovial tissues are responsible for the signs and symptoms of joint inflammation and for the eventual destruction of articular and periarticular structures that lead to joint dysfunction and disability. The three most abundant cell populations in RA synovium are synovial macrophages (type A synoviocytes), synovial fibroblasts (type B synoviocytes) and infiltrating T lymphocytes. Other important cell populations include B lymphocytes, dendritic cells, plasma cells, mast cells and osteoclasts. Our current understanding of rheumatoid arthritis is moving beyond previous concepts that view this disease as the consequence of a specific and focused humoral or cellular autoimmune response to a single autoantigen. Rather, a new view of rheumatoid arthritis is emerging, which seeks to understand this disease as the product of pathologic cell-cell interactions occurring within a unique and defined environment, the synovium. T lymphocytes in rheumatoid arthritis synovium interact closely with dendritic cells, the most potent antigen-presenting cell population in the immune system. T cells also interact with monocytes and macrophages and cytokine-activated T cells may be, especially, suited to trigger production of the important cytokine TNFalpha by synovial macrophages. Recent evidence also suggests a potent bidirectional interaction between synovial T cells and synovial fibroblasts, which can lead to activation of both cell types. An important role for synovial B lymphocytes has been emphasized recently, both by experimental data and by results of clinical interventions. B cells in synovium can interact with fibroblasts as well as with other cells of the immune system and their potential role as antigen-presenting cells in the joint is as yet underexplored. Rheumatoid arthritis synovium may be one of the most striking examples of pathologic, organ-specific interactions between immune system cells and resident tissue cell populations. This view of rheumatoid arthritis also leads to the prediction that novel approaches to treatment will more logically target the intercellular communication systems that maintain such interactions, rather than attempt to ablate a single cell population.
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Affiliation(s)
| | | | - David A. Fox
- Corresponding author. Tel.: +1 734 936 5566; fax: +1 734 763 1253., (D.A. Fox)
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Manoj S, Babiuk LA, van Drunen Littel-van den Hurk S. Approaches to enhance the efficacy of DNA vaccines. Crit Rev Clin Lab Sci 2004; 41:1-39. [PMID: 15077722 DOI: 10.1080/10408360490269251] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
DNA vaccines consist of antigen-encoding bacterial plasmids that are capable of inducing antigen-specific immune responses upon inoculation into a host. This method of immunization is advantageous in terms of simplicity, adaptability, and cost of vaccine production. However, the entry of DNA vaccines and expression of antigen are subjected to physical and biochemical barriers imposed by the host. In small animals such as mice, the host-imposed impediments have not prevented DNA vaccines from inducing long-lasting, protective humoral, and cellular immune responses. In contrast, these barriers appear to be more difficult to overcome in large animals and humans. The focus of this article is to summarize the limitations of DNA vaccines and to provide a comprehensive review on the different strategies developed to enhance the efficacy of DNA vaccines. Several of these strategies, such as altering codon bias of the encoded gene, changing the cellular localization of the expressed antigen, and optimizing delivery and formulation of the plasmid, have led to improvements in DNA vaccine efficacy in large animals. However, solutions for increasing the amount of plasmid that eventually enters the nucleus and is available for transcription of the transgene still need to be found. The overall conclusions from these studies suggest that, provided these critical improvements are made, DNA vaccines may find important clinical and practical applications in the field of vaccination.
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Affiliation(s)
- Sharmila Manoj
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Canada
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10
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Gill MB, Roecklein-Canfield J, Sage DR, Zambela-Soediono M, Longtine N, Uknis M, Fingeroth JD. EBV attachment stimulates FHOS/FHOD1 redistribution and co-aggregation with CD21: formin interactions with the cytoplasmic domain of human CD21. J Cell Sci 2004; 117:2709-20. [PMID: 15138285 DOI: 10.1242/jcs.01113] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CD21 is a multifunctional receptor for Epstein-Barr virus (EBV), for C3dg and for CD23. Upon engagement of immune complexes CD21 modulates immunoreceptor signaling, linking innate and adaptive immune responses. The mechanisms enabling CD21 to independently relay information between the exterior and interior of the cell, however, remain unresolved. We show that formin homologue overexpressed in spleen (FHOS/FHOD1) binds the cytoplasmic domain of human CD21 through its C terminus. When expressed in cells, EGFP-FHOS localizes to the cytoplasm and accumulates with actin in membrane protrusions. Plasma membrane aggregation, redistribution and co-localization of both proteins are stimulated when EBV (ligand) binds CD21. Though widely expressed, FHOS RNA is most abundant in the littoral cell, a major constituent of the red pulp of human spleen believed to function in antigen filtration. Formins are molecular scaffolds that nucleate actin by a pathway distinct from Arp2/3 complex, linking signal transduction to actin reorganization and gene transcription. Thus, ligand stimulation of FHOS-CD21 interaction may transmit signals through promotion of cytoskeletal rearrangement. Moreover, formin recruitment to sites of actin assembly initiated by immunoreceptors could be a general mechanism whereby co-receptors such as CD21 modulate intracellular signaling.
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MESH Headings
- 3T3 Cells
- Adenoviridae/genetics
- Animals
- B-Lymphocytes/cytology
- B-Lymphocytes/metabolism
- Cell Line, Transformed
- Cell Line, Tumor
- Cell Transformation, Viral
- Cytoplasm/chemistry
- Cytoplasm/metabolism
- Fetal Proteins/metabolism
- Fluorescent Antibody Technique, Indirect
- Formins
- Green Fluorescent Proteins/metabolism
- HeLa Cells
- Herpesvirus 4, Human/metabolism
- Humans
- Mice
- Microscopy, Fluorescence
- Models, Biological
- Nuclear Proteins/metabolism
- Protein Binding
- Protein Structure, Tertiary
- Receptors, Complement 3d/chemistry
- Receptors, Complement 3d/metabolism
- Recombinant Fusion Proteins/metabolism
- T-Lymphocytes/cytology
- T-Lymphocytes/metabolism
- Two-Hybrid System Techniques
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Affiliation(s)
- Michael B Gill
- Division of Infectious Diseases, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA
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Agarwal S, Ramanathan U, Naresh KN. Epstein-Barr virus association and ALK gene expression in anaplastic large-cell lymphoma. Hum Pathol 2002; 33:146-52. [PMID: 11957137 DOI: 10.1053/hupa.2002.31925] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Anaplastic large cell lymphoma of T/null-cell type (ALCL) is associated with a characteristic genetic abnormality t(2;5) that results in the NPM-ALK chimeric gene and the protein product derived thereof. In 10% to 20% of ALCLs, the translocation partners of the ALK gene are genes other than NPM (variant translocations). ALK gene expression limited to the cytoplasm implies a variant translocation. In this study, we have investigated 46 cases of ALCL for expression and localization of ALK protein and its association with Epstein-Barr virus (EBV) (by hybridization to EBV-encoded nuclear RNA-1 [EBER-1] and immunostaining for LMP-1). ALCL patients with a null cell phenotype were significantly younger as compared with those of T-cell phenotype (mean age: 28 years v 42 years; P =.018). Sixteen of 46 ALCL cases (34%) were ALK positive. ALK-positive patients were significantly younger (mean age: 25 years for those with both cytoplasmic and nuclear staining; 22 years for those with exclusive cytoplasmic staining; and 41 years for those negative for the ALK gene; P =.023). EBER-1 was detected in 9 of 46 cases (20%), and LMP-1 expression was noted in 5 of them. By polymerase chain reaction analysis, all EBV-associated cases that were investigated showed type I EBV. Whereas 2 of 23 T-cell ALCLs (9%) were EBER-1+, and 7 of 23 null-cell ALCLs (30%) showed EBV association (P =.057). EBV association was seen in 20% of ALK-negative cases, in 0% of cases with ALK gene expression in both nucleus and cytoplasm, and in 60% of cases with ALK gene expression exclusively in the cytoplasm (P =.02). Further, although ALK-positive-EBER-1+ cases were LMP-1 negative, ALK-negative-EBER-1+ cases were LMP-1 positive. Our study raises the question whether EBV might have an etiological role in the evolution of ALCLs that lack classical t(2;5).
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MESH Headings
- Adult
- Age Factors
- Anaplastic Lymphoma Kinase
- Chromosomes, Human, Pair 2
- Chromosomes, Human, Pair 5
- Gene Expression
- Herpesvirus 4, Human/genetics
- Humans
- Immunophenotyping
- Lymphoma, Large B-Cell, Diffuse/genetics
- Lymphoma, Large B-Cell, Diffuse/virology
- Polymerase Chain Reaction
- Protein-Tyrosine Kinases/genetics
- RNA, Viral/analysis
- Receptor Protein-Tyrosine Kinases
- T-Lymphocytes
- Translocation, Genetic
- Viral Matrix Proteins/genetics
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Affiliation(s)
- Sandhya Agarwal
- Department of Pathology, Tata Memorial Hospital, Parel, Mumbai, India
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12
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Suradhat S, Braun RP, Lewis PJ, Babiuk LA, van Drunen Littel-van den Hurk S, Griebel PJ, Baca-Estrada ME. Fusion of C3d molecule with bovine rotavirus VP7 or bovine herpesvirus type 1 glycoprotein D inhibits immune responses following DNA immunization. Vet Immunol Immunopathol 2001; 83:79-92. [PMID: 11604163 DOI: 10.1016/s0165-2427(01)00369-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The binding of the complement C3d molecule with receptors on B cells and/or follicular dendritic cells (FDCs) influences the induction of humoral immune responses. For example, C3d fused to an antigen has been shown to have a strong adjuvant effect on antibody production. We investigated the possibility that co-expression of antigen and C3d as a fusion protein could enhance antigen-specific immune responses, following plasmid immunization. One or two copies of murine C3d-cDNA, C3d or (C3d)(2), respectively, were cloned together with bovine rotavirus (BRV) VP7 or bovine herpesvirus type 1 (BHV-1) glycoprotein D (gD) genes. All constructs contained a signal peptide that resulted in the secretion of the expressed proteins. In vitro, the characterization of the chimeric proteins indicated that both VP7 and gD retained their antigenicity and the C3d remained biologically active. However, immunization with plasmids encoding VP7-C3d chimeras did not enhance rotavirus-specific antibody responses and the frequency of BRV-specific IFN-gamma secreting cells in the spleens were significantly lower in mice immunized with pVP7-(C3d)(2) when compared with mice immunized with plasmid encoding VP7. The same pattern of immune responses was observed for plasmids encoding gD-C3d. Both gD-specific antibody responses and the frequency of gD-specific IFN-gamma secreting cells were significantly lower in mice immunized with plasmid expressing gD-C3d chimeras when compared with mice immunized with plasmid encoding gD alone. These results indicate that co-expression of C3d with an antigen actually inhibit both humoral and cell-mediated antigen-specific immune responses.
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Affiliation(s)
- S Suradhat
- Veterinary Infectious Disease Organization (VIDO), University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, Canada S7N 5E3
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