Specificity of transfer factor. In vitro lymphoblast transformation of peripheral lymphocytes to Leishmania major antigen in the presence of transfer factor.

The in vivo and in vitro demonstration of specificity of transfer factor (TF) has so far been hampered by lack of a suitable antigen. The host partiality of Leishmania suggested that in the case of leishmania antigen it should be possible to obtain lymphocytes of both donors and recipients of TF which were either sensitized or truly virgin. Lymphoblast transformation of normal donor lymphocytes to leishmania major antigen (LMA) was therefore measured in the presence of TF prepared from donors with a history of cutaneous leishmania infection (LSTFd) and normal donors (NSTFd). A clear augmentation of the lymphoblast transformation equal to that usually seen when lymphocytes from sensitized individuals are exposed to LMA was observed with LSTFd. An insignificant increase in lymphoblast transformation, however, occurred when NSTFd was used together with LMA and when LSTFd or NSTFd was used alone. The results, although limited by the number of TF preparations, tested, clearly substantiate the in vitro specificity of TF.