Different stimulating capacity of monocytes and B lymphocytes in mixed leukocyte cultures: a dose response study.

Cell fractions highly enriched either for monocytes of for B lymphocytes were separated from human peripheral blood. They were tested for their capacity to stimulate allogeneic lymphocytes in mixed leukocyte cultures, using dose-response titrations. Neither population could be stimulated to proliferate by allogeneic cells, but both proved strong stimulators. In this respect monocytes were more efficient than B cell preparations. Differences were pronounced at the lower numbers of stimulating cells but were no longer significant with large amounts of cells.