PHARMACOLOGICAL MODIFICATION OF IMMUNOREGULATORY LYMPHOCYTES-T .2. MODULATION OF LYMPHOCYTE-T CELL-SURFACE CHARACTERISTICS

Abstract

Human peripheral blood lymphocytes were fractionated into non-T lymphocyte, T lymphocyte, theophylline-resistant (TR) and theophylline-sensitive (TS) T lymphocyte subpopulations. The proportion of cells bearing surface membrane Ig (sIg), complement component Clq, antigen, .beta.2 microglobulin and T lymphocyte specific antigens detected by monoclonal antibodies OKT3, OKT4, OKT5 and OKT8 was studied using immunofluorescent techniques. Incubation of T lymphocytes or TR lymphocytes with adenosine or impromidine, an H2 histamine agonist, under conditions previously shown to increase Fc.gamma. receptors and radioresistant suppressor cell activity, was found to increase the proportion of cells expressing readily detectable surface .beta.2 microglobulin and the antigen detected by OKT8. Cells expressing OKT4 antigen declined and there was no change in OKT3, OKT5, Ia, Clq, sIg or sheep erythrocyte receptor expression. The expression of T lymphocyte Fc.gamma. receptors, .beta.2 microglobulin and the antigens detected by the monoclonal antibodies OKT4 and OKT8 are, at least in part, apparently regulated by agents acting upon adenosine and H2 histamine receptors.