Functional activation of encephalitogenic T cells in the absence of antigen-presenting cells.
Co-stimulatory signals provided by surface receptors of antigen-presenting cells (APC) are crucial for the activation of CD4+ T cells, classically measured by cell proliferation or IL-2 secretion. The contribution of APC co-stimulatory signals to the acquisition of various effector functions by activated T cells is not fully understood. We have now examined the importance of surface-mediated co-stimulation by APC for activation of the effector potential of T cell clones mediating experimental allergic encephalomyelitis (EAE). We now report that T cell clones can be activated to produce EAE not only with APC but also by antibody-mediated TCR cross-linking in the presence of a mixture of T cell growth factors. Without activation, the T cell clones did not cause EAE. Therefore, at least some types of T cells can be activated to express their effector potential in the absence of any surface co-stimulatory signals requiring intact APC.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry; D000938:Antigen-Presenting Cells / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002999:Clone Cells; D003432:Cross-Linking Reagents; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000276:immunology*; D005260:Female; D008213:Lymphocyte Activation / Q000276:immunology*; D051381:Rats; D011917:Rats, Inbred Lew; D011948:Receptors, Antigen, T-Cell / Q000737:chemistry
D000911:Antibodies, Monoclonal; D003432:Cross-Linking Reagents; D011948:Receptors, Antigen, T-Cell