Mixed cultures of fetal and adult lymphocytes

Abstract Lymphocyte responses in the mixed cultures of fetal and adult allogenic lymphocytes have been studied by means of a labeling technique. Fetal lymphocytes were obtained from the thymus, spleen, and cord blood from fetuses of 79 to 115 days (11 to 15 weeks) of estimated ovulation age. The results showed wide variation but indicated that these cells can synthesize DNA in the presence of allogenic lymphocytes. Analyses of mitotic cells showed that both thymocytes or splenocytes and adult lymphocytes are capable of stimulating and reacting to each other to undergo mitoses. Mixed cultures of splenocytes from four pairs of unrelated fetuses revealed a considerable increase of DNA synthesis; those of thymocytes showed a negligible level of response.