Human cytomegalovirus induces apoptosis in the hematopoietic cell line MO7e

Several studies have shown that human cytomegalovirus (HCMV) induces growth suppression of hematopoietic progenitors. In vitro studies have demonstrat ed that the HCMV-induced suppression is independent of viral protein produc tion. Previous studies have indicated a link between HCMV infection and apo ptosis in human cells. The purpose of our study was to investigate whether the observed inhibitory effect of HCMV on the human myeloid progenitors cou ld be connected to the induction of apoptosis. The growth and cell death of the hematopoietic cell line MO7e was investigated following infection with HCMV virions and dense bodies. Both virions and dense bodies inhibited the growth of MO7e cells, and induced cell death measured by trypan blue stain ing. In addition, both HCMV Virions and dense bodies caused an increased am ount of apoptosis-characteristic DNA fragmentation in the MO7e cells compar ed to mock-treated cells. The HCMV virions were also able to induce an incr eased expression of phosphatidylserine on the cell surface, which is an ear ly event in the initiation of apoptosis in most cell types. In conclusion, HCMV and HCMV dense bodies are able to induce apoptosis in the myeloid prog enitor cell line MO7e.