Objective To identify the role of RNA-editing enzyme ADAR1 (adenosine deaminase acting on RNA) in EV71 infection and virus mutation.Methods RNAi technology was applied to establish ADAR1 knock-down stable cell lines.Then the cells were served to evaluate the role of ADAR1 in EV71 infection by MTT assay for detecting virus-induced cell viability,virus plaque assay for quantification of the virus titer and the cellular susceptibility to the virus,and Western blot for virus protein expressions.ADAR1-mediated RNA editing can result in the genetic A-G and T-C mutations.To further determine whether the effects of ADAR1 on EV71 infection were correlated with ADAR1-mediated EV71 RNA editing and therefore increased the viral mutations during the infection,the characteristics of EV71 mutation were analyzed based on the different full-length viral genomes from epidemic regions.The viral genome was also sequenced from the infected ADAR1 knock-down cells.Results After ADAR1 knock-down,the cell viability decreased quickly after the virus infection,and formed much more and larger sizes of plaques than the control cells.The virus capsid protein VP1 expressions and virus titer in the cells culture media were both increased in ADAR1 knockdown cells.Statistic analysis showed that A-G and T-C mutations were the major mutations of EV71,which were believed to be the hot sites for RNA-editing.However,the results of viral RNA genomic sequencing data indicated that ADAR1 did not edit EV71 genome directly.Conclusions ADAR1 was a restriction factor for controlling EV71.However,ADAR1 does not directly edit EV71 genome.

OBJECTIVETo investigate the risk factors and therapeutic outcome of acute graft versus host disease (aGVHD) in patients with acute leukemia after haploidentical peripheral hematopoietic stem cell transplantation.

METHODSThe clinical data of 19 cases of acute leukemia underwent haploidentical hematopoietic stem cell transplanttion during January 2010 and December 2010 were retrospectively analyzed. The effects of patients sex, donor-recipient sex difference, donor age, conditioning regimen, dosage of anti-thymocyte globulin(ATG), mononuclear cell and CD34cell counts on the intestinal aGVHD were analyzed by Logistic regression.

RESULTSIntestinal aGVHD occurred in 5 cases with 1 case at stage II 3 cases at stage III and 1 case at stage IV on the 7th, 22th, 27th, 70th and 154th day after transplantation, respectively. Single factor analysis showed that the patient's sex, donor-recipient sex difference, donor age, dosage of ATG, mononuclear cell and CD34cell counts were not related with the occurrence of the intestinal aGVHD, and the conditoning regimen was the risk factor for the intestinal aGVHD. 2 cases among 5 cases with intestinal aGVHD were treated with methylprednisolone at dosage of 1 mg/kg per day, 1 case was treated with methylprednisolone therapy combined with tacrolimus. 2 cases of methylprednisolone-resistance were treated with CD25 monoclonal antibody. Intestinal aGVHD of all patients was improved after the above-mentioned treatment.

CONCLUSIONConditioning regimen of haploidentical peipheral hematopoieitc stem cell transplantaion has effects on the intestinal aGVHD, which needs to be confirmed by further research.