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Updated: Aug 8, 2026

Murine Model of CD40-activation of B cells
Published on: March 6, 2010
CD226 (DNAM-1) is involved in lymphocyte function-associated antigen 1 costimulatory signal for naive T cell
Kazuko Shibuya1, Jun Shirakawa, Tomie Kameyama
1Laboratory for Immune Receptor, RIKEN Research Center for Allergy and Immunology, 3-1-1 Koyadai, Ibaraki 305-0074, Japan. ashibuya@rtc.riken.go.jp
Abstract:
Upon antigen recognition by the T cell receptor, lymphocyte function-associated antigen 1 (LFA-1) physically associates with the leukocyte adhesion molecule CD226 (DNAM-1) and the protein tyrosine kinase Fyn. We show that lentiviral vector-mediated mutant (Y-F322) CD226 transferred into naive CD4+ helper T cells (Ths) inhibited interleukin (IL)-12-independent Th1 development initiated by CD3 and LFA-1 ligations. Moreover, proliferation induced by LFA-1 costimulatory signal was suppressed in mutant (Y-F322) CD226-transduced naive CD4+ and CD8+ T cells in the absence of IL-2. These results suggest that CD226 is involved in LFA-1-mediated costimulatory signals for triggering naive T cell differentiation and proliferation. We also demonstrate that although LFA-1, CD226, and Fyn are polarized at the immunological synapse upon stimulation with anti-CD3 in CD4+ and CD8+ T cells, lipid rafts are polarized in CD4+, but not CD8+, T cells. Moreover, proliferation initiated by LFA-1 costimulatory signal is suppressed by lipid raft disruption in CD4+, but not CD8+, T cells, suggesting that the LFA-1 costimulatory signal is independent of lipid rafts in CD8+ T cells.
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