Inclusion of a CRF01_AE HIV envelope protein boost with a DNA/MVA prime-boost vaccine: Impact on humoral and cellular immunogenicity and viral load reduction after SHIV-E challenge.

The current study assessed the immunogenicity and protective efficacy of various prime-boost vaccine regimens in rhesus macaques using combinations of recombinant DNA (rDNA), recombinant MVA (rMVA), and subunit gp140 protein. The rDNA and rMVA vectors were constructed to express Env from HIV-1 subtype CRF01_AE and Gag-Pol from CRF01_AE or SIVmac 239. One of the rMVAs, MVA/CMDR, has been recently tested in humans. Immunizations were administered at months 0 and 1 (prime) and months 3 and 6 (boost). After priming, HIV env-specific serum IgG was detected in monkeys receiving gp140 alone or rMVA but not in those receiving rDNA. Titers were enhanced in these groups after boosting either with gp140 alone or with rMVA plus gp140. The groups that received the rDNA prime developed env-specific IgG after boosting with rMVA with or without gp140. HIV Env-specific serum IgG binding antibodies were elicited more frequently and of higher titer, and breadth of neutralizing antibodies was increased with the inclusion of the subunit Env boost. T cell responses were measured by tetramer binding to Gag p11c in Mamu-A*01 macaques, and by IFN-γ ELISPOT assay to SIV-Gag. T cell responses were induced after vaccination with the highest responses seen in macaques immunized with rDNA and rMVA. Macaques were challenged intravenously with a novel SHIV-E virus (SIVmac239 Gag-Pol with an HIV-1 subtype E-Env CAR402). Post challenge with SHIV-E, antibody titers were boosted in all groups and peaked at 4 weeks. Robust T cell responses were seen in all groups post challenge and in macaques immunized with rDNA and rMVA a clear boosting of responses was seen. A greater than two-log drop in RNA copies/ml at peak viremia and earlier set point was achieved in macaques primed with rDNA, and boosted with rMVA/SHIV-AE plus gp140. Post challenge viremia in macaques immunized with other regimens was not significantly different to that of controls. These results demonstrate that a gp140 subunit and inclusion of SIV Gag-Pol may be critical for control of SHIV post challenge.

Transmission of STLV in a closed colony of macaques.

A 3.3% seroprevalence of simian T-lymphotropic virus (STLV) was found in a closed breeding and research colony of rhesus and cynomolgus macaques in Thailand. Epidemiology of STLV within the colony was assessed by means of a retrospective analysis of banked and freshly collected serum samples, and a review of the animals' medical records. Evidence was found that the virus had been imported into the colony by some of the original animals, and was subsequently transmitted both vertically and horizontally. The cell-associated nature of STLV was demonstrated by iatrogenic transmission of the virus following a whole blood transfusion, but there was no transmission to animals that received only serum from the same infected donor. Transmission by all routes was infrequent, as indicated by the overall seroprevalence of 3.3% (14 of 420 samples) after the colony had been closed for 11 years. Maternal-infant transmission appeared to be < 12%.

Treatment of persistent self-injurious behavior in rhesus monkeys through socialization: a preliminary report.

This paper is a retrospective report describing outcomes for six male rhesus monkeys, each with a history of persistent self-injurious behavior (SIB), after their social introduction to female rhesus monkeys. Pairing procedures for five of the six male primates were implemented after surgical vasectomy. One male had previous pairing experience with a female prior to vasectomy resulting in an unplanned pregnancy. This male was re-socialized with his former female partner after surgery. The SIB-related medical histories of the males before and after the pairings are presented. One goal for promoting pair-housing of chronic SIB male monkeys with female monkeys was to determine whether this intervention would function to reduce or eliminate the expression of SIB and thus provide enhanced socialization opportunities for previously singly housed animals.