title: Alteration in DNA synthetic response of thymocytes from NZB mice of different ages.
abstract: Thymocytes from NZB and DBA/2 mice were injected into lethally irradiated C57 B1/6 recipients. DNA synthesis in spleen and lymph node was measured as the incorporation of radioactive 5-iodo-2-deoxyuridine. The generation of cytotoxic effector cells was also studied in an in vitro cytotoxicity assay, with EL-4 lymphoma target cells. The kinetics of DNA synthesis were similar for 2- and 8-week-old DBA/2 donors and for 2-week-old NZB donors with a peak on day 4. Thymocytes from 8-week-old and 9-month-old NZB donors showed a delayed onset of DNA synthesis which was still increasing on day 6. When NZB donor thymocytes from 2- and 8-week-old mice were mixed together before injections, as few as 25% of 8-week-old cells gave a DNA synthetic response characteristic of this aged population. These results suggest an abnormal thymocyte development in NZB mice which may relate to the subsequent emergence of autoimmune disease.
mesh_terms: D000367:Age Factors; D000818:Animals; D002460:Cell Line; D002860:Chromium Radioisotopes; D003601:Cytotoxicity Tests, Immunologic; D004247:DNA / Q000096:biosynthesis*; D006648:Histocompatibility; D007065:Idoxuridine / Q000378:metabolism; D007457:Iodine Radioisotopes; D008213:Lymphocyte Activation; D008223:Lymphoma / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008814:Mice, Inbred NZB / Q000276:immunology*; D011828:Radiation Chimera; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000637:transplantation; D014184:Transplantation, Homologous
chemical_list: D002860:Chromium Radioisotopes; D007457:Iodine Radioisotopes; D004247:DNA; D007065:Idoxuridine