Functional antibody response to human cytomegalovirus in immunocompetent and HIV-1 infected individuals with antibodies that inhibit virus penetration into cells and intercellular transmission of viral infection

Antibodies mediating post-attachment virus neutralisation (PN), inhibition of human cytomegalovirus (HCMV)-induced cell fusion in the glioblastoma cel l line U373 (IF) and global neutralising activity (NA) were quantified in s era from healthy immunocompetent individuals, asymptomatic HIV-1-infected s ubjects and AIDS patients to further characterise the neutralising antibody response to HCMV in these population groups and to assess whether HIV-1-in fected individuals exhibited an abnormal functional antibody profile. PN an d IF antibodies accounted for a minor fraction of the NA activity of sera f rom all population groups. Sera from HIV-1-infected individuals (particular ly AIDS patients) displayed higher levels of PN and IF antibodies than thos e from the healthy control group; however, the relative contribution of the se antibodies to the global serum NA activity appeared to be lower in the f ormer individuals than in immunocompetent controls, Serum antibodies preven ting HCMV cell-to-cell spread (IP) were then measured to determine whether a specific deficiency could be detected in the HIV-1-infected group populat ion. Serum IP antibody titres were significantly higher in HIV-1-infected i ndividuals (particularly in AIDS patients) than in controls. The potential implications of the data for explaining the pathogenesis of HCMV infection are discussed.