LYMPHOCYTE ACTIVATION II. DISCRIMINATING STIMULATION OF LYMPHOCYTE SUBPOPULATIONS BY PHYTOMITOGENS AND HETEROLOGOUS ANTILYMPHOCYTE SERA.

The mitogenic selectivity of four phytomitogens, phytohaemagglutinin (PHA), concanavalin (ConA), lentil mitogen (LM) and pokeweed mitogen .(PWM), and a series of heterologous antilymphocyte sera (ALS) for mouse T and B lymphocytes has been investigated using thymidine uptake as a measure of proliferative activity. The results show that PHA, ConA and LM stimulate T but not B cells whereas PWM activates both T and B cells. Of six mitogenically active ALS, five were T cell specific and one B cell specific. Cortisone resistant (T) cells within the thymus showed a much greater response to all mitogens than unselected thymocytes. However, ConA and LM activated a considerable response in the latter population. Selective activation of T and B cells by aspecific means may be useful both as a clinical tool and as an approach to gaining an understanding of antigen induction of immune responses. [ABSTRACT FROM AUTHOR]