Stimulation and inhibition of hematopoiesis by the MLC reaction

The effect of an MLC reaction on mouse and human hematopoiesis in vitro was studied. The growth of murine T- and B-lymphocyte colonies as well as myeloid colonies was enhanced during early days of MLC, while a marked decrease of colony formation was evident starting from day +4 of MLC. Allogeneic reaction initially stimulates hematopoiesis, while on its peak a marked inhibition of the proliferation and differentiation of progenitor cells occurs.