RESUMO
AbstractObjective: To establish an acquired aplastic anemia animal model for investigating the function of T lymphocyte and the pathogenesis and treatment of aplastic anemia(AA). METHODS: To establish the acquired aplastic anemia mouse model through the X-ray irradiation in combination with lymphocytes injection. AA Group: the purified Pan T lymphocytes from the spleen of C57BL/6J mice were enriched and injected to the mice through tail vein(5×106), the CB6F1 mice were exposed to 3,4 and 5 Gy X-ray irradiation; TBI Group: the CB6F1 mice were exposed to 3,4 and 5 Gy X-ray irradiation, and were injected with the same volume of PBS buffer; Control group: the CB6F1 mice were only injected with the same volume of PBS buffer. The peripheral blood routine was examined and the number of nucleated cells in bone marrow were calculatedï¼the hematopoiesis changes in bone marrow was examinedï¼flow cytometry was used to examine the distribution of T lymphocytes in bone marrow, and it also used to examine the apoptosis of bone marrow cells and the differentiation of spleen T lymphocytes. RESULTS: Compared with 4, 5 Gy irradiated mice in AA groups, the survival time of 3 Gy irradiated AA groups was significantly prolonged. 3, 4 and 5 Gy X-ray irradiation combined with Pan T lymphocyte injection could successfully induced severe reduction of red blood cells, blood neutrophils, and platelets, severe reduction of bone marrow nucleated cells, severe bone marrow hematopoietic failure, and the significant expansion of T lymphocytes ratio in the bone marrow. CD4+ and CD8+ T cells were both increased, but mainly on CD8+ T cells, and could promote the differentiation of T cells from naïve T cells to effector memory T cells. CONCLUSION: 3, 4 and 5 Gy X-ray irradiation combined with 5×106 pan-T cell injection could successfully induce acquired aplastic anemia through T lymphocyte hyperfunction. Compared with 4, 5 Gy irradiated AA group, the 3 Gy irradiated AA group shows significantly longer survival time, and the peripheral blood routine profile closely resembles the clinical manifestations of AA patients.