Electron microscopic study of contactual interaction of sensitized lymphocytes with homologous target cells

When the lymph node cells sensitized by Ehrlich ascites tumor were mixed and cultured with JTC-ll cells derived from Ehrlich ascites tumor, the interaction of the two cell groups exhibited a contactual phenomenon accompanied by the destruction of JTC-ll cells. These two cell groups in contact were fixed with OsO4, solution and the ultra-thin sections were observed in the electron microscope. As a result the following findings were obtained. In the interaction where lymph node cells become attached to JTC-ll cells, resulting in the destruction of JTC-ll cells, lymphnode cells were also destroyed. Effector cells seem to be a kind of cells in the lymph nodes, and from their morphological characteristics they are considered to be lymphocytes. Electron microscopic observations of the surface of contact revealed the following: some cells are adhered to one another at the surfaces of the cell membranes that run in parallel; some are in contact by means of filamentous projection of lymhocytes; the cell membranes of the two cells form interdigitation; and both surfaces of two cell membranes are disrupted at the point of contact and the cytoplasm of the two cells appears to be directly connected with one another.