[Electron microscopic study of the interaction between cytolytic T-lymphocytes and target cells].

Thymocytes stimulated in vitro in a mixed culture was sorbed by centrifugation on the surface of target cells for electron microscope study of cytology of immune T-lymphocytes and early cytolysis periods. A well developed Golgi apparatus was revealed in the cytoplasm of lymphocytes; there was also accumulation of tubular structures 50 to 60 nm in diameter which communicated with the cysterns of the granular endoplasmic reticulum, with "descended" vesiculi and plasmatic membrane of lymphocyte. This membrane formed numerous contacts with the membrane of target cells thus producing closed clefts.

[Proliferation and cytotoxicity of thymus lymphocytes in vitro].

Proliferative and cytollytical activity of lymphocytes was compared in lymphocyte alloimmunization of the spleen and intact thymus. The count of live cells and DNA-synthesizing cells in the thymocyte monoculture was 10--15-fold, and in mixed thymus cell culture--about 5-fold lower than the corresponding amounts of spleen cells. The index of immune thymocyte stimulation was several times greater than that of the immune cells of the spleen.

[Effect of avitaminosis B6 in mice on the function of the T-lymphocytes in vitro].

The influence of different degrees of avitaminosis B6 in mice on the cytolytic activity of T-lymphocytes measured by the amount of Na2Cr51O4 released from the lysed target cells was studied on a model of primary immune response in a mixed lymphocyte culture in vitro. Keeping of the animals for 3 weeks on pyridoxine-free diet failed to influence the capacity of lymphocytes to proliferate in vitro and their cytolytic activity. In animals on pyridoxine-free diet for 45 days the amount of pyridoxal 5(1)-phosphate in the spleen decreased by 55% in comparison with control.