Role of interferon alpha (IFN-alpha) and interferon gamma (IFN-gamma) in the control of the infection of monocyte-like cells with human cytomegalovirus (HCMV)

The role of cytokines in the control of HCMV infection has been studied in THP-1 cells, a macrophage-like cell model and in MRCS cells. HCMV replicati on was studied by immune detection of viral immediate-early antigens (IEA) and virus yield was evaluated in MRC-5 cells by immunoperoxidase staining, Pretreatment of MRC-5 and phorbol 12-myristate 13-acetate (PMA)-treated THP -1 cells with IFN-alpha or IFN-gamma for 24 hr prior to the infection reduc ed the number of infected cells and virus yield. A synergistic anti-CMV act ivity in synthesis of early proteins was obtained with these cytokines in c ombination with TNF-alpha in differentiated THP-1 cells only. Treatment of HCMV-infected differentiated THP-1 cells or MRC-5 cells with IFN-alpha or I FN-gamma alone had no inhibitory effect on virus replication, however the v irus yield was reduced with ganciclovir, A synergistic anti-CMV activity in virus yield was obtained only when infected differentiated THP-1 cells wer e treated with ganciclovir in combination with IFN-gamma. The current study shows that IFN-alpha and IFN-gamma can play a role in the reduction of HCM V replication in macrophage-like cells and in the efficiency of therapies w ith ganciclovir in this cell type and that the anti-CMV effect of cytokines may be different in fibroblasts and in macrophage-like cells.