T-T cell interactions are mediated by adhesion molecules.
The mechanism by which T cells signal other T cells is not well defined. This was investigated by studying the ability of circulating T cells to induce the proliferation of autologous T cell clones. Peripheral blood T cells activated by cross-linking of the CD3/T cell receptor complex, which increased the expression of cell adhesion molecules LFA-1, LFA-3 and ICAM-1, induced the proliferation of autologous T cell clones. Irradiated antigen-activated peripheral blood T cells could also induce the proliferation of T cell clones which could not recognize that antigen. T-T cell activation required cell contact, was not major histocompatibility complex (MHC) restricted and was blocked by monoclonal antibodies directed against adhesion molecules CD2 and LFA-3 but was not blocked by antibody to class II MHC determinants. As CD2 is the natural ligand for LFA-3, increased expression of T cell surface adhesion molecules LFA-1, ICAM-1 and particularly LFA-3 during an inflammatory response may rapidly recruit T cells that are activated through the CD2 pathway. These results allow a simplified model to explain how relatively few antigen/MHC-specific T cells can recruit large numbers of non-antigen-specific T cells in the generation of an inflammatory response and postulates a novel role of the CD2 molecule in T cell immune function.
Brod
S A
SA
Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115.
Purvee
M
M
Benjamin
D
D
Hafler
D A
DA
D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D000954:Antigens, Surface / Q000502:physiology; D017252:CD3 Complex; D018968:CD58 Antigens; D015815:Cell Adhesion Molecules / Q000502:physiology*; D002450:Cell Communication; D002999:Clone Cells; D006801:Humans; D016130:Immunophenotyping; D007376:Interleukin-2 / Q000502:physiology; D008213:Lymphocyte Activation / Q000276:immunology; D016169:Lymphocyte Function-Associated Antigen-1 / Q000502:physiology; D008562:Membrane Glycoproteins / Q000502:physiology; D008934:Mitogens / Q000494:pharmacology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology* / Q000528:radiation effects
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D017252:CD3 Complex; D018968:CD58 Antigens; D015815:Cell Adhesion Molecules; D007376:Interleukin-2; D016169:Lymphocyte Function-Associated Antigen-1; D008562:Membrane Glycoproteins; D008934:Mitogens; D011948:Receptors, Antigen, T-Cell