Functional role of VLA-1 (CD49A) in adhesion, cation-dependent spreading, and activation of cultured human T lymphocytes.
The functions of VLA-1 (CD49a, alpha 1 beta 1 integrin), a potential ECM protein receptor on activated human T lymphocytes in vivo, were investigated. Within a panel of 25 long-term cultured IL-2-dependent T cell lines, tau delta and CD8+ alpha beta cells expressed significantly higher levels of alpha 1 beta 1 than CD4+ alpha beta cells. While VLA-1-high tau delta or CD8+ cells adhered to plastic wells coated with collagen IV, collagen I, or fibronectin, moAb 1B3.1 to VLA-1 only inhibited the adherence to collagen IV. tau delta and CD8+ VLA-1-high T cells layered upon collagen IV in the presence of Mg2+ also spread elongated cytoplasmic extensions, which were abrogated by moAb 1B3.1. In contrast, spreading on fibronectin or spontaneous non-ECM-related spreading were not inhibited. Crosslinking of surface VLA-1 molecules with plastic-bound moAb 1B3.1 selectively induced expression of IL-2R on two of six VLA-1+ clones, both of which expressed tau delta TCR. Thus, CD49a is a specific collagen IV receptor in VLA-1-high tau delta and CD8+ alpha beta cells and can transmit signals to these lymphocytes to spread and express IL-2R.
Department of Medicine F, Chaim Sheba Medical Center, Tel Hashomer, Israel.
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D000911:Antibodies, Monoclonal; D016827:CD8 Antigens / Q000378:metabolism; D002412:Cations; D002448:Cell Adhesion / Q000276:immunology; D002460:Cell Line; D002465:Cell Movement / Q000276:immunology; D002999:Clone Cells / Q000276:immunology / Q000502:physiology; D003094:Collagen / Q000378:metabolism; D006801:Humans; D008213:Lymphocyte Activation; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000378:metabolism; D016029:Receptors, Very Late Antigen / Q000276:immunology* / Q000502:physiology; D013601:T-Lymphocytes / Q000276:immunology* / Q000502:physiology
D000911:Antibodies, Monoclonal; D016827:CD8 Antigens; D002412:Cations; D016692:Receptors, Antigen, T-Cell, gamma-delta; D016029:Receptors, Very Late Antigen; D003094:Collagen