Augmentation of cell mediated lysis (CML) by THF.

The in-vitro model of cell mediated lysis (CML) was used to study whether a thymic hormone (THF) participates in the processes which lead to generation of effector cells. It was found that THF increases the capacity of effector cells from spleens of intact mice in the CML assay. This effect of THF on generation of effector cells was manifested when THF was present during the mixed lymphocyte culture. On the other hand, addition of THF to the effector (CML) phase did not elevate the lytic capacity of killer cells. Moreover, THF compensated the impaired lytic capacity of effector cells from adult thymectomized mice and raised it to the level of intact mice. The results are compatible with the hypothesis that THF acts on the generation of CML effector cells of both intact and adult thymectomized mice.