Abnormalities of T Cells From PBL And SFL From Patients with Rheumatoid Arthritis and from PBL from Patients with Systemic Lupus Erithematosus in PHA Induced Class II Antigens Expression and in Autologous Mixed Lymphocyte Reaction.

HLA class II antigens definitely play an important role in activation of human T lymphocytes either in allogeneic mixed lymphocyte reaction (MLR) or in autologous mixed lymphocyte reactions (AMLR) of both non T and T/T type 1 − 3 − 4 − 5 − 6 − 7 fact monoclonal antibodies (MoAb) anti-HLA class II antigens inhibit both MLR or AMLRs according to the different determinants they recognize 6 − 8 − 9 − 10 − 11 − 12 . Moreover it has been shown that the T cell subpopulation CD4 proliferates in the AMLR non T/T while the CD8 proliferates in the T/T one 15 . Furthermore, human T lymphocytes, which usually do not express cl.II Ags. at rest, can not stimulate MLR and T/T AMLR 6 , whereas in vivo activated T lymphocytes from patients with Infections Mononucleosis or from synovial fluid of patients with Rheumatoid Arthritis do stimulate, because they express these antigens 13 − 14