title: Complement receptor immunoglobulin: a control point in infection and immunity, inflammation and cancer.
abstract: The B7 family-related protein, V-set and Ig domain (VSIG4) / Z39Ig / complement receptor immunoglobulin (CRIg), is a new player in the regulation of immunity to infection and inflammation. The unique features of this receptor as compared with classical complement receptors, CR3 and CR4, have heralded the emergence of new concepts in the regulation of innate and adaptive immunity. Its selective expression in tissue macrophages and dendritic cells has been considered of importance in host defence and in maintaining tolerance against self-antigens. Although a major receptor for phagocytosis of complement opsonised bacteria, its array of emerging functions which incorporates the immune suppressive and anti-inflammatory action of the receptor have now been realised. Accumulating evidence from mouse experimental models indicates a potential role for CRIg in protection against bacterial infection and inflammatory diseases, such as rheumatoid arthritis, type 1 diabetes and systemic lupus erythematosus, and also in promotion of tumour growth. CRIg expression can be considered as a control point in these diseases, through which inflammatory mediators, including cytokines, act. The ability of CRIg to suppress cytotoxic T cell proliferation and function may underlie its promotion of cancer growth. Thus, the unique properties of this receptor open up new avenues for understanding of the pathways that regulate inflammation during infection, autoimmunity and cancer with the potential for new drug targets to be identified. While some complement receptors may be differently expressed in mice and humans, as well as displaying different properties, mouse CRIg has a structure and function similar to the human receptor, suggesting that extrapolation to human diseases is appropriate. Furthermore, there is emerging evidence in human conditions that CRIg may be a valuable biomarker in infection and immunity, inflammatory conditions and cancer prognosis.
authors.affiliation: Department of Molecular and Cellular Biology, School of Biological Science, University of Adelaide, South Australia; Robinson Research Institute, Disciplines of Paediatrics and Obstetrics and Gynaecology, School of Medicine, University of Adelaide, South.
authors.forename: Annabelle Grace
authors.initials: AG
authors.lastname: Small
authors.affiliation: Department of Molecular and Cellular Biology, School of Biological Science, University of Adelaide, South Australia; Robinson Research Institute, Disciplines of Paediatrics and Obstetrics and Gynaecology, School of Medicine, University of Adelaide, South.
authors.forename: Marwah
authors.initials: M
authors.lastname: Al-Baghdadi
authors.affiliation: Robinson Research Institute, Disciplines of Paediatrics and Obstetrics and Gynaecology, School of Medicine, University of Adelaide, South Australia; Department of Immunopathology, SA Pathology, Women's and Children's Hospital, South Australia.
authors.forename: Alex
authors.initials: A
authors.lastname: Quach
authors.affiliation: Robinson Research Institute, Disciplines of Paediatrics and Obstetrics and Gynaecology, School of Medicine, University of Adelaide, South Australia; Department of Immunopathology, SA Pathology, Women's and Children's Hospital, South Australia.
authors.forename: Charles
authors.initials: C
authors.lastname: Hii
authors.affiliation: Department of Molecular and Cellular Biology, School of Biological Science, University of Adelaide, South Australia; Robinson Research Institute, Disciplines of Paediatrics and Obstetrics and Gynaecology, School of Medicine, University of Adelaide, South.
authors.forename: Antonio
authors.initials: A
authors.lastname: Ferrante
mesh_terms: D056704:Adaptive Immunity / Q000276:immunology; D000818:Animals; D001172:Arthritis, Rheumatoid / Q000276:immunology; D016207:Cytokines / Q000276:immunology; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology; D007136:Immunoglobulins / Q000276:immunology*; D007239:Infections / Q000276:immunology*; D007249:Inflammation / Q000276:immunology*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D051379:Mice; D009369:Neoplasms / Q000276:immunology*; D010587:Phagocytosis / Q000276:immunology; D011951:Receptors, Complement / Q000276:immunology*; D017463:Receptors, Complement 3b / Q000276:immunology
chemical_list: C509991:CR1 protein, human; D016207:Cytokines; D007136:Immunoglobulins; D011951:Receptors, Complement; D017463:Receptors, Complement 3b; C414427:VSIG4 protein, human; C509992:VSIG4 protein, mouse