Abstract
Abstract: :
Purpose: To evaluate chemokine gene expression and secretion in CMV infected human retinal pigment epithelial cells (HRPE). Method: HRPE cultures were infected with HCMV (strain AD 169) and culture supernatants were collected at 1,3,5,7,9 and 11 days post-inoculation. The levels of chemokines, IL-8, MCP-1, MCP-3 and RANTES derived from culture supernatants were determined by ELISA. Total RNA prepared from uninfected and HCMV infected HRPE were used for the analyses of the steady state levels of chemokine mRNA by RT-PCR. The effect of MCP-1 on HCMV replication in HRPE was evaluated by virus plaque assay. Results: HRPE cultures infected with HCMV exhibited characteristic cytopathic effects at various times post inoculation. RT-PCR analyses showed significant reduction in MCP-1 and MCP-3 mRNA in HCMV infected HRPE when compared to time matched uninfected HRPE. In contrast, HCMV infection enhanced IL-8 mRNA levels while RANTES mRNA could not be detected in either control or infected HRPE. Analyses of chemokine protein secretion revealed significant decrease in MCP-1( p < 0.01) and MCP-3 (p < 0.05), and a significant increase in IL-8 ( p < 0.05). There was no detectable secretion of RANTES in either control or HCMV infected HRPE. When CMV infected HRPE cells were exposed to exogenous MCP-1, virus replication was not affected. Conclusion: HCMV infection of HRPE cells resulted in differential regulation of the expression of MCP-1, MCP-3 and IL-8. Since these chemokines are involved in the migration and activation of leukocytes to the sites of infection, HCMV induced modulation of chemokines may participate in immune evasion and / or immunopathological processes in CMV retinitis.
Keywords: 382 cytomegalovirus • 380 cytokines/chemokines • 568 retinitis