title: Electron microscopic observations on T and B lymphocytes from spleens of syngeneic radiation chimaeras.
abstract: The ultrastructure of T and B lymphocytes has been examined in long-term syngeneic chimaeras and age-control mice. Spleen cell suspensions from these mice were passed through glass wool columns to obtain pure lymphocyte populations. These cells were then separated into T and B lymphocytes by nylon wool columns, and their purity was tested by cytotoxicity assays with anti-phi serum. Electron microscopic observations on such separated T and B lymphocytes did not reveal morphological differences except when the cells were fully differentiated, either as mature (T2) cells or plasmacells. In particular, T2 cells showed a very high cytoplasmic density, attributable to the presence of a larger number of microfilaments with respect to immature (T1) cells. In long-term chimaeras a significantly larger number of T2 cells was found as compared to age-control mice, and this morphological observation is correlated with the differences in immune reactivity and leukemia incidence previously described in these mice.
mesh_terms: D000367:Age Factors; D000818:Animals; D001402:B-Lymphocytes / Q000648:ultrastructure*; D001854:Bone Marrow Cells; D016026:Bone Marrow Transplantation; D002469:Cell Separation; D003593:Cytoplasm / Q000648:ultrastructure; D003599:Cytoskeleton / Q000648:ultrastructure; D007111:Immunity, Cellular; D007942:Leukemia, Experimental / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D011828:Radiation Chimera; D013154:Spleen / Q000276:immunology / Q000648:ultrastructure; D013601:T-Lymphocytes / Q000648:ultrastructure*; D014185:Transplantation, Isogeneic