Molecular cloning of two west African HIV2 isolates that replicate well in macrophages

HIV2 strains were isolated from a Gambian with neuro-AIDS (HIV2D194) and from an asymptomatic Ghanian (HIV2D205). Like HIV1 biological subtype c, both isolates grew slowly and induced few or no syncytia, but eventually produced high levels of particle-associated reverse transcriptase (RT) in cultures of fresh peripheral blood lymphocytes. Each produced even higher levels of RT in fresh human macrophages, especially HIV2D194, where maximal RT values of 1,800,000 cpm/ml supernatant of approximately 30,000 cells were measured. The viruses were molecularly cloned after a single passage in culture. Restriction site analysis showed heterogeneity within each isolate. Nucleotide sequence analysis of HIV2D194 revealed that, genetically, it is a member of the prototypic HIV2 family, displaying 12% divergence vs. HIV2ROD and HIV2NIHZ. In contrast, HIV2D205 is the most highly divergent HIV2 strain yet described: it is equidistant in relation between the known HIV2 strains and the SIVMAC isolates (23-24% nucleotide sequence divergence).