Enhanced CD3-mediated T lymphocyte proliferation in patients with systemic lupus erythematosus.

Nonfractionated peripheral blood lymphocytes from patients with systemic lupus erythematosus (SLE) showed enhanced proliferative responses when stimulated via the CD3 pathway. In contrast, proliferative responses induced by phytohemagglutinin were diminished in SLE patients. Levels of CD3-induced interleukin-2 production and interleukin-2 receptor expression were comparable with normal levels. Highly purified T cells also showed augmented CD3 responses, but only in the presence of phorbol myristate acetate or a combination of phorbol myristate acetate plus calcium ionophore A23187, and not with calcium ionophore alone. The data suggest integrity of the T cell receptor/CD3 pathway for T cell activation in patients with SLE, as examined in cultures stimulated with specific anti-CD3 monoclonal antibodies rather than with multivalent lectins. An increased response via the CD3 complex could contribute to the autoimmune activity in human SLE.