Heterogeneity of Blastogenic Factors Produced in Vitro by Antigenically Stimulated and Unstimulated Leukocytes

[摘要] Blastogenic factor derived from antigenically stimulated or unstimulated leukocyte cultures was studied. Cell-free medium (CFM) from unmixed leukocyte cultures was frequently stimulatory for both autologous and allogeneic cells. However, the blastogenic factor usually stimulated allogeneic cells much more than autologous cells. The blastogenic factor which is stimulatory only for allogeneic cells may be a soluble form of histocompatibility antigen. The CFM preparations that were the most stimulatory toward allogeneic cells were not necessarily the most active toward autologous cells. The two types of stimulatory activity showed no correlation. It seems probable that CFM from unmixed cultures of leukocytes contains at least two components: a) a specific blastogenic factor (histocompatibility antigen), and b) a nonspecific stimulatory factor (probably identical to the “potentiating factor” described by Janis and Bach). Blastogenic factor was produced in vitro by tuberculin-sensitive leukocytes in response to PPD-stimulation. The production of this factor was antigenically-specific, but once produced, it was as active for autologous cells as for allogeneic cells. This factor is not histocompatibility antigen. The continuous presence of antigen was not required for activity. This factor may be different from the “lymphocyte-activating factor” described by Valentine and Lawrence. When the medium was changed every 2 days, the blastogenic factor was produced repeatedly until the culture died. The present findings indicate that the blastogenic factor produced by PPD-stimulation differs from that which is produced in unmixed cultures and which is stimulatory only for allogeneic cells. However, it is not known whether there are differences between the blastogenic factor arising from PPD-stimulation and the factor which is produced in unmixed cultures and which stimulates autologous cells.

[学科分类] 生物科学（综合）