In vitro hemopoiesis of W/WV and +/+ marrow cells cultured alone and with thymocytes.

To evaluate the effects of thymocytes from anemic W/WV mice on hemopoiesis in vitro, we co-cultured thymocytes from W/WV mice or from their non-anemic +/+ littermates with W/WV or +/+ marrow cells in semi-solid systems designed to foster colonial growth from neutrophil/macrophage (CFUNM), early erythroid (BFUE), late erythroid (CFUE) precursors. The marrow cell to thymocyte ratios in the cultures were 1:3 and 1:20 (1:175 for CFUNM). Untreated or anti-theta serum (ATS) or mock (control) AT treated marrow cells were cultured with the thymocytes. We found that marrow from +/+ and W/WV mice contain equivalent concentrations of CFUNM but W/WV marrow has a lower concentration of BFUE than +/+ marrow. Neither +/+ nor W/WV thymoctyes, in the concentrations used, effected any increase in the numbers of CFUNM or CFUE colonies formed from untampered or antiserum treated marrow cells. In two groups, thymocytes effected a slight increase in the numbers of bursts (BFUE colonies) formed from marrow cell suspensions and in both of these groups W/WV thymocytes were as effective as +/+ thymocytes. Thus, under the conditions studied, W/WV thymocytes were not more inhibitory or less stimulatory for in vitro hemopoiesis than were normal thymocytes.