Inhibition of vesicular stomatitis virus replication in the course of HIV infection in patients with different stages of immunodeficiency.

The replication of vesicular stomatitis virus (VSV) in isolated human leukocytes has been used to measure the level of nonspecific antiviral immunity. However, during infection with some pathogens, the main effect observed is caused by interaction between the pathogen and VSV. This was also noted in advanced stages of HIV infection, when an inverse association between HIV viral load and VSV replication was found. The mutual effect was markedly stronger than the correlation between the VSV replication level and CD4(+) T-cell count. Since successful antiretroviral therapy is associated with a decrease in HIV viremia to undetectable levels, the effect of such therapy on VSV replication was expected and confirmed in this investigation. In fact, increased VSV titers were observed together with decreased HIV viral load, particularly in the case of efficient therapeutic schemes, for example those including lopinavir/ritonavir. The results showed that VSV replication capacity reflected the progression of HIV infection. Moreover, the presence of interferon in the plasma of AIDS patients was found to be only partially responsible for the inhibition of VSV replication. The results suggest a specific HIV-VSV interaction, whether direct or indirect. Thus the VSV replication assay may be applied in evaluating the stage of HIV infection.