HIV-1 infectious molecular clones
The plasmid encoding the full-length infectious molecular clone of HIV-1Lai was obtained from the NIH AIDS Reagent and Reference Program. The HIV-1Lai/Bal-Env infectious molecular clone was constructed by replacing the envelope (env) gp160 amino acids 103–717 of the HIV-1Lai (B subtype that utilizes CXCR4) molecular clone with the corresponding region of HIV-1Bal (B subtype that utilizes CCR5). The HIV-1Lai/Bal-Env chimeric virus uses CCR5 as a secondary receptor. The infectious molecular clone of HIV-198IN22 was constructed using DNA extracted from PBMC that were infected with a primary isolate of HIV-198IN22. HIV-1Lai/Bal-Env and HIV-198IN22 mutant viruses were constructed by introducing point mutations using standard PCR-based mutagenesis methods.