Elevated numbers of SCART1+ gammadelta T cells in skin inflammation and inflammatory bowel disease.
The members of the scavenger receptor cysteine-rich (SRCR) superfamily group B have diverse functions, including roles in the immune system. For years it has been known that the WC1 protein is expressed on the surface of bovine gammadelta T cells, and more recent studies indicate that WC1(+) gammadelta T cells respond to stimulation with bacterial antigens by producing interferon-gamma. The SRCR proteins CD5, CD6, Sp alpha, CD163, and DMBT1/gp-340 are also involved in the immune response, since they are pattern recognition receptors capable of binding directly to bacterial and/or fungal components. Here, we investigate a novel murine SRCR protein named SCART1. The ectodomain and the full-length SCART1 were expressed in mammalian cells and used to raise monoclonal antibodies against the ectodomain for immunohistochemical and FACS analysis. Immunohistochemical analysis shows that SCART1 is expressed in a range of lymphoid organs and epithelial-rich tissues by a subset of T cells identified as being gammadelta T cells by FACS analysis. SCART1 was present in 86% of the gammadelta T cells and was not found in CD4(+) or CD8(+) T cells. The numbers of SCART1(+) cells were elevated in two mouse models of human diseases: skin inflammation and inflammatory bowel disease. In the skin inflammation model, an 8.6-fold increase in SCART1(+) cells was observed. Finally, recombinant SCART1 protein was found not to bind to selected bacterial or fungal components or to whole bacteria. Our results show that SCART1 is a novel gammadelta T cell marker and it is therefore likely that SCART1 plays a role in the immune response.
Fink
Dorte Rosenbek
DR
Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Winsløwparken 25.3, 5000 Odense, Denmark.
Holm
Dorte
D
Schlosser
Anders
A
Nielsen
Ole
O
Latta
Markus
M
Lozano
Francisco
F
Holmskov
Uffe
U
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology; D015153:Blotting, Western; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D003872:Dermatitis / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D015212:Inflammatory Bowel Diseases / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008811:Mice, Inbred DBA; D011485:Protein Binding; D051381:Rats; D017207:Rats, Sprague-Dawley; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology* / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D014162:Transfection
D000911:Antibodies, Monoclonal; D008565:Membrane Proteins; D016692:Receptors, Antigen, T-Cell, gamma-delta; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; C530761:SCART1 protein, mouse