HUMAN CD4 HELPER T-CELL ACTIVATION - FUNCTIONAL INVOLVEMENT OF 2 DISTINCT COLLAGEN RECEPTORS, 1F7 AND VLA INTEGRIN FAMILY

In the present study, we showed that activation of human CD4 T cells can be induced by anti- CD3 and collagen in a serum-free system. This activation was inhibited by the addition ofpeptides containing the RGD or Gly-Pro-X sequences. Significantly, we demonstrated that both the 1177 (CD26) structure and the VLA integrin family, particularly the VLA3 complex, contribute to the functional interaction between collagen and CD4 cells since anti-1177 and antiVLA3 specifically inhibited this collagen-induced CD4 cell activation. Biochemical studies showed that the 1177 structure is not a member of the VLA integrin family. These results thus indicated that two different families of antigens serve as functional collagen receptors for CD4 T cell activation. © 1990, Rockefeller University Press., All rights reserved.