Comparative study of Tat vaccine regimens in Mauritian cynomolgus and Indian rhesus macaques: influence of Mauritian MHC haplotypes on susceptibility/resistance to SHIV(89.6P) infection.

Protection afforded by HIV Tat-based vaccines has differed in Indian rhesus and Mauritian cynomolgus macaques. We evaluated native Tat and Ad-HIVtat priming/Tat-boosting regimens in both species. Both vaccines were immunogenic.

A replication-competent adenovirus-human immunodeficiency virus (Ad-HIV) tat and Ad-HIV env priming/Tat and envelope protein boosting regimen elicits enhanced protective efficacy against simian/human immunodeficiency virus SHIV89.6P challenge in rhesus macaques.

We previously demonstrated that replication-competent adenovirus (Ad)-simian immunodeficiency virus (SIV) recombinant prime/protein boost regimens elicit potent immunogenicity and strong, durable protection of rhesus macaques against SIV(mac251). Additionally, native Tat vaccines have conferred strong protection against simian/human immunodeficiency virus SHIV(89.6P) challenge of cynomolgus monkeys, while native, inactivated, or vectored Tat vaccines have failed to elicit similar protective efficacy in rhesus macaques.

A complementary single-stranded docking site is required for enhancement of strand exchange by human immunodeficiency virus nucleocapsid protein on substrates that model viral recombination.

Enhancement of strand exchange by nucleocapsid protein (NC) is proposed to occur during retroviral recombination. The mechanism was examined using an RNA (donor)-DNA hybrid that mimicked a retrovirus replication intermediate. This consisted of a 25 base pair hybrid region flanked on each side by single-stranded RNA or DNA.

Differing roles of the N- and C-terminal zinc fingers in human immunodeficiency virus nucleocapsid protein-enhanced nucleic acid annealing.

The replication process of human immunodeficiency virus requires a number of nucleic acid annealing steps facilitated by the hybridization and helix-destabilizing activities of human immunodeficiency virus nucleocapsid (NC) protein. NC contains two CCHC zinc finger motifs numbered 1 and 2 from the N terminus. The amino acids surrounding the CCHC residues differ between the two zinc fingers.

Evidence for the differential effects of nucleocapsid protein on strand transfer in various regions of the HIV genome.

An in vitro strand transfer assay that mimicked recombinational events occurring during reverse transcription in HIV-1 was used to assess the role of nucleocapsid protein (NC) in strand transfer. Strand transfer in highly structured nucleic acid species from the U3 3' long terminal repeats, gag-pol frameshift region, and Rev response element were strongly enhanced by NC. In contrast, weakly structured templates from the env and pol-vif regions transferred well without NC and showed lower enhancement.