Recombination between human immunodeficiency viruses (HIV) type 1 and 2 results in generation of defective hybrid viruses.

Dual infection by HIV-1 and HIV-2 is already documented. To test if this could lead to recombination and generation of altered viruses, recombination between HIV-1 and HIV-2 DNAs was studied. Release of recombinant viruses was detected following cotransfection of human rhabdomyosarcoma cells with truncated versions of these proviral DNAs. Linearization of plasmid DNAs was required for virus production. Analysis of viral particles by hybridization revealed the presence of viral RNA. However viral replication was not evident. A computer search of the overlap region between the substrate DNAs revealed 66% homology despite an overall genomic sequence homology of only 35%. These data suggest possible generation of replication-deficient hybrid viruses as a result of recombination between HIV-1 and -2.