Genetic comparison of LAV-related isolates

LAV/HTLV-III has been found to be the etiological cause of AIDS. This new human retrovirus has a selective tropism for T lymphocytes of the OKT4/leu 3 subset, in which it induces a cytopathic effect. We have compared Southern blot patterns of integrated proviral DNAs from different individuals at risk or not using a nick-translated LAV probe. We find that LAV/HTLV-III is very similar to our Haitian isolate and close to an isolate from an early-recognized (in 1982) AIDS case in New York. More variation is apparent with Zaïrian isolates as well as an isolate from a nonhigh-risk group when we used Hind III or Bgl II Sac-digested fragments. We also looked at virus isolated from a Sicilian child who developed AIDS after allogenic bone marrow transplant and transfusion. This isolate shows two forms: One is similar to the prototype LAV, the second much different.