The surface morphology of mitogen-stimulated human peripheral blood lymphocytes.

The changes occurring in surface morphology during the transformation of normal peripheral blood lymphocytes by phytohaemagglutinin (PHA) are described and the surface ultrastructure of the PHA-induced blasts is compared with that of pokeweed mitogen (PWM)-and rabbit anti-beta2-microglobulin antiserum-induced blasts. Both mitogen-specific and non-specific changes were observed and their possible relationship to the activation of lymphocyte subpopulations is discussed. Similar surface characteristics found in various tissue lymphoid cells are also described.