AIDS (London, England) 2017 12 12() doi 10.1097/QAD.0000000000001724
Non-human primates (NHPs) are the only animal model that can be used to evaluate protection efficacy of HIV-1 Env vaccines. However, whether broadly neutralizing antibodies (bnAbs) can be elicited in NHPs infected with simian/human immunodeficiency virus (SHIV) has not been fully understood. The objective of this study is to investigate whether broad neutralization activities were developed in SHIV-infected macaques after long-term infection as in humans.
Neutralization breadth and specificities in plasmas from SHIV-infected macaques could be determined by analyzing a panel of tier 2 viruses and their mutants.
Forty-four Chinese macaques infected with SHIV1157ipd3N4, SHIVSF162P3 or SHIVCHN19P4 were followed for 54-321 weeks. Archived plasmas from 19 macaques were used to determine neutralization breadth and specificities against 17 tier 2 Env-pseudoviruses.
Longitudinal plasma from three SHIVSF162P3-infected macaques and three SHIV1157ipd3N4-infected macaques rarely neutralized viruses (<25%) within one year of infection. The neutralization breadth in two SHIV1157ipd3N4-infected macaques significantly increased (≥65%) by year 6. Four of six SHIV1157ipd3N4-infected macaques could neutralize 50%-75% viruses while none of macaques infected with SHIVSF162P3 or SHIVCHN19P4 could neutralize more than 25% of viruses after 6 years of infection (p = 0.035). Neutralization specificity analysis showed mutations resistant to bnAbs in V2, V3 or CD4bs regions could abrogate neutralization by year-6 plasma from three SHIV1157ipd3N4-infected macaques. CONCLUSIONS
These results demonstrate that bnAbs targeting common HIV-1 epitopes can be elicited in SHIV1157ipd3N4-infected macaques as in humans after 4-6 years of infection and SHIV/NHP can serve as an ideal model to study bnAb maturation.