OBJECTIVETo investigate the mechanism and the suppression effect of human cytomegalovirus (HCMV) on hematopoietic system.

METHODSSemi-solid culture system was used to observe the effect of HCMV AD169 strain on colony forming unit granulocyte/macrophage (CFU-GM), CFU-erythroid (CFU-E), CFU-multipotent (CFU-Mix) and CFU-megakaryocyte (CFU-MK) growth. The techniques of in situ polymerase chain reaction (IS-PCR) and polymerase chain reaction (PCR) were used to demonstrate the existence of HCMV DNA in the colony cells of cultured CFU-GM, CFU-Mix, CFU-MK and CFU-E, respectively. The immediate early antigen (IEA) mRNA in CFU-MK and late antigen (LA) mRNA in CFU-E were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). HCMV early protein P52 was detected with immunohistochemical technique.

RESULTSHCMV AD169 suppressed the differentiation and proliferation of CFU-GM, CFU-E, CFU-Mix and CFU-MK in vitro significantly (P < 0.05). The suppression was dose-dependent. HCMV DNA was successfully detected in CFU-GM, CFU-Mix, CFU-MK colony cells from viral infection groups by IS-PCR, and was detected in CFU-E by PCR, while it was negative in blank control or mock control groups. CFU-MK colony cells expressed HCMV IEA mRNA with the size of 340 bp in virus infection groups of 10(3) plague forming unit (PFU), 10(4) PFU and 10(5) PFU, respectively. The HCMV LA mRNA was detected by RT-PCR and was 263 bp long in positive control group of HCMV-infected human embryonic fibroblasts. The expression of HCMV LA mRNA in CFU-E was negative. The early protein P52 of HCMV in 10(4) PFU group was also identified by immunohistochemical staining.

CONCLUSIONHCMV AD169 strains inhibited the differentiation and proliferation of CFU-GM, CFU-E, CFU-Mix and CFU-MK by the infection of the hematopoietic progenitors. HCMV might cause the suppression of hematopoiesis by direct infection, which is thought to be one of the reasons of HCMV infection associated with thrombocytopenia, neutropenia and anemia.