Interaction of CD2 with its ligand, LFA-3, in human T cell proliferation.
Recently, it has been demonstrated that lymphocyte function-associated Ag (LFA-3) is a natural ligand for CD2 and that this receptor-ligand interaction functions in cell-cell adhesion. In this report, we demonstrate that LFA-3 plays a role in T cell activation. L cells were transfected with human genomic DNA and sorted for expression of LFA-3. We demonstrate that LFA-3+ L cells, together with anti-CD3 mAb or with suboptimal doses of PHA, stimulate proliferation of human peripheral blood T cells. Furthermore, thymocyte proliferation was induced by LFA-3+ L cells and suboptimal doses of PHA. Proliferation was inhibited by mAb directed against either CD2 or LFA-3. Stimulation of thymocytes by the combination of PHA and LFA-3+ L cells resulted in the increased expression of the IL-2R, as well as of the surface Ag 4F2, transferrin receptor, and HLA-DR. These data support the conclusion that LFA-3 plays a role in CD2-dependent T cell activation. LFA-3 is widely distributed and is expressed on all APC and target cells. Thus, the ability of the CD2/LFA-3 interaction to costimulate with an anti-CD3 mAb suggests that the CD2/LFA-3 interaction may be involved not only in an Ag-independent alternate pathway of T cell activation but also in Ag-specific T cell activation.
Bierer
B E
BE
Department of Medicine, Brigham and Women's Hospital, Boston, MA.
Barbosa
J
J
Herrmann
S
S
Burakoff
S J
SJ
D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis / Q000276:immunology*; D000954:Antigens, Surface / Q000032:analysis / Q000276:immunology*; D002448:Cell Adhesion; D002450:Cell Communication; D006801:Humans; D007223:Infant; D007739:L Cells; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1; D051379:Mice; D010641:Phenotype; D013601:T-Lymphocytes / Q000032:analysis / Q000276:immunology*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D016169:Lymphocyte Function-Associated Antigen-1; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7