THE EFFECT OF HUMAN CYTOMEGALOVIRUS ON SELECTED FUNCTIONS OF PERIPHERAL-BLOOD MONOCYTES

The effect of in vitro infection of human cytomegalovirus (HCMV) on va rious monocyte functions relevant to antimicrobial defence mechanisms has been investigated: the phagocytic activity of monocytes, the relea se of lysozyme and intracellular concentration of acid phosphatase, an d the release of the cytokines interleukin-1 (IL-1), IL-6, and tumour necrosis factor-alpha (TNF-alpha). HCMV significantly inhibited the re lease of lysozyme and intracellular concentration of acid phosphatase. Regarding the phagocytic activity and the release of cytokines, there was considerable variation in the HCMV effect among the different blo od donors tested. There was no clear tendency in the observed results; both stimulation and inhibition were seen. The HCMV-specific pp65 was detected in the nucleus of about 1% of the monocytes 3 h after infect ion and HCMV-specific IE antigens were found in about 0.1% of the mono cytes 2 days postinfection. No E- or L-gene expression was observed an d no infectious virus was produced in the monocytes. Our results indic ate that HCMV infection may influence monocyte functions in spite of n o productive infection of these cells.