title: Effects of mitogenic and antigenic stimulaton on the thymidine kinases of mouse spleen cells in vivo and in vitro.
abstract: The DNA-synthesizing ability of mouse spleen cells in vitro and in vivo is paralleled by their levels of cytoplasmic thymidine kinase. However, a very high level of nuclear-associated enzyme activity developed in cultures of both non-stimulated and mitogen-transformed lymphocytes. This activity did not appear in the spleens of mice during the primary immune response to sheep erythrocytes (SRC) or following administration of Convanavalin A (Con A). Feedback inhibition studies with TTP demonstrated that the nuclear enzymes were more sensitive than the cytoplasmic activities. The thermal stabilities of the nuclear enzymes were also found to be greater than the corresponding cytoplasmic ones. Furthermore, analysis of the rate of thermal inactivation indicated that both the cytoplasmic and nuclear enzymes present in transformed lymphocytes in vitro were far more heat-stable than those activities normally found in the mouse spleen, even after antigenic challenge with SRC in vivo or incubation in vitro in the absence of mitogenic stimulation.
mesh_terms: D000941:Antigens; D002467:Cell Nucleus / Q000201:enzymology; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D003593:Cytoplasm / Q000201:enzymology; D004247:DNA / Q000096:biosynthesis; D004912:Erythrocytes / Q000276:immunology; D005246:Feedback; D006358:Hot Temperature; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000201:enzymology* / Q000378:metabolism; D008934:Mitogens / Q000494:pharmacology*; D013937:Thymidine Kinase / Q000378:metabolism*; D013942:Thymine Nucleotides / Q000494:pharmacology
chemical_list: D000941:Antigens; D008070:Lipopolysaccharides; D008934:Mitogens; D013942:Thymine Nucleotides; D003208:Concanavalin A; D004247:DNA; D013937:Thymidine Kinase