Reactivity of antiserum to human brain with peripheral blood lymphocytes.

Antisera to human brain (AHBS) and human thymocytes (AHTS) were produced in rabbits and selectively absorbed to render them specific for T cells. After absorption AHBS, but not AHTS, lost most of its cytotoxic activity against T cells. Absorbed AHBS bound up to 95% of peripheral blood T lymphocytes as detected by indirect immunofluorescence and inhibited up to 46% of the lytic activity of AHTS; however, it was incapable of inhibiting the E-rosette formation of T lymphocytes. All 10 samples of human peripheral blood lymphocytes, pretreated with AHBS, were significantly suppressed in their response to antigens, but fewer samples were affected in their response to mitogens and to allogeneic stimulation, indicating diversity in the nature of the receptors involved in the cellular responses.