OBJECTIVETo investigate the complete blood count, morphological changes, follicular T helper (Tfh) cells and expression of PD-1 in bone marrow and spleen of mice with myelodysplastic syndrome(MDS) and to explore their significance in pathogenesis of MDS.

METHODSThe 10 male NUP98-HOXD13 transgenic mice and 10 male homologous wild-type C57BL/6J mice were used for experments. The complete blood count, morphological change of NUP98-HOXD13 transgenic mice and wild-type C57BL/6J were detected by routine methods. The level of Tfh cells and expression of PD-1 in bone marrow and spleen were measured by flow cytometry. The PD-1 mRNA of bone marrow mononuclear cells and spleen cells were analyzed by real-time PCR method.

RESULTSThe counts of RBC, neutrophile and platelet in above- mentioned transgenic mice were less than that in wild type C57BL/6J mice. As compared with wild type C57BL/6J mice, the morphology of RBC and platelet in transgenic mice was some abnormal, including bi-nucleated erythrocytes, ringed mucleated neutrophil and erythroblastic islands. The count of Tfh cells in transgenic mice was less than that in wild type mice, but the expression of PD-1 was higher. The expression of BMMNC PD-1 mRNA was obviously higher than that in wild type mice.

CONCLUSIONThe pancytopenia and dysplasia, decrease of Tfh cells and increase of PD-1 expression have been observed in NUP98-HOXD13 transgenic mice, which may be one of important reasons for promoting malignant clone and leading to impair anti immune respones.