The interaction of mycoplasmas with mammalian cells. II. Monocytes and lymphocytes.

The incubation of mycoplasmas with human peripheral blood buffy coats resulted in the uptake of these microorganisms by more than 50% of the mononuclear cells. Mycoplasmas adhered to the plasma membranes of all leukocytes, most of which developed long cytoplasmic processes not seen in the controls. In human and rat thoracic duct lymph, about 6% of the cells ingested the microorganisms. T(2) phage and thorotrast were taken up by a similar percentage of lymphocytes. On morphological grounds, the cells which were able to take up PPLO's or particles could not be distinguished from the cells which were incapable of this function. Following phagocytosis, neither the cell nor the microorganism showed any morphological alterations over a 3 hr period of observation. The demonstration that a small percentage of "lymphocytes" are able to phagocytose may have pathological and immunological implications.