PERSISTENCE OF 4 RELATED HUMAN-IMMUNODEFICIENCY-VIRUS SUBTYPES DURINGTHE COURSE OF ZIDOVUDINE THERAPY - RELATIONSHIP BETWEEN VIRION RNA AND PROVIRAL DNA

Human immunodeficiency virus (HIV) virion RNA and proviral DNA sequenc es have been examined over a 1-year period in an HIV-seropositive pati ent, commencing with the start of zidovudine treatment. Ey characteriz ing the variable V3 and V4 env domains, four related but structurally discrete genotypes could be identified prior to the start of therapy a nd during the subsequent 60-week period of therapy. Each of the four s ubtypes showed a unique pattern in the preservation of glycosylation s ites. A comparison of the V3 amino acid sequences in peripheral blood mononuclear cell proviral DNA and plasma virion RNA at 0, 24, 36, and 60 weeks demonstrated that proviral DNA did not serve as a predictor o f the structure of virion RNA. HIV virion RNA subtype 3 was the most p revalent virion RNA subtype at three of the four periods studied, yet no corresponding proviral DNA was detected. Other virion subtypes have been observed, but only on a transient basis. The present data are co nsistent with a model of HN infection in which related but different H N substrains coexist and evolve independently within an individual. Ch aracterization of virion RNA may be required to identify the unique pr operties of the virus involved in disease progression; characterizatio n of proviral DNA will not yield this information.