Differential susceptibility of human peripheral blood lymphocyte subpopulations to mitogenic activation. Influence of methylprednisolone.

The inhibition of the mitogenic activation of human peripheral blood lymphocyte (PBL) subpopulations by methylprednisolone (MP) was dependent on the mitogen used. Purified human T cells were more sensitive to the effects of MP than were B cells or PBLs, especially when these cells were activated by pokeweed mitogen (PWM). MP did not function by inhibiting binding of mitogen to the cell surface. After being mitogenically activated, human lymphocytes were resistant to the effects of MP. These effects of MP were shown to be reversible. Monocytes did not provide a significant degree of protection to mitogenically activated human T cells incubated with MP. These data suggest that MP-induced inhibition of the mitogenic activation of human PBLs may be a reflection of lymphocyte heterogeneity, and that the differential sensitivity of PBLs to MP may be used to isolate functionally different subpopulations of these cells.