Vaccination against heterologous R5 clade C SHIV: prevention of infection and correlates of protection

PLoS One. 2011;6(7):e22010. doi: 10.1371/journal.pone.0022010. Epub 2011 Jul 20.

Abstract

A safe, efficacious vaccine is required to stop the AIDS pandemic. Disappointing results from the STEP trial implied a need to include humoral anti-HIV-1 responses, a notion supported by RV144 trial data even though correlates of protection are unknown. We vaccinated rhesus macaques with recombinant simian immunodeficiency virus (SIV) Gag-Pol particles, HIV-1 Tat and trimeric clade C (HIV-C) gp160, which induced cross-neutralizing antibodies (nAbs) and robust cellular immune responses. After five low-dose mucosal challenges with a simian-human immunodeficiency virus (SHIV) that encoded a heterologous R5 HIV-C envelope (22.1% divergence from the gp160 immunogen), 94% of controls became viremic, whereas one third of vaccinees remained virus-free. Upon high-dose SHIV rechallenge, all controls became infected, whereas some vaccinees remained aviremic. Peak viremia was inversely correlated with both cellular immunity (p<0.001) and cross-nAb titers (p<0.001). These data simultaneously linked cellular as well as humoral immune responses with the degree of protection for the first time.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Fusion Proteins, gag-pol / immunology
  • HIV Envelope Protein gp160 / immunology
  • HIV Infections / immunology
  • HIV Infections / prevention & control*
  • HIV-1 / immunology*
  • Humans
  • Infant
  • Macaca mulatta
  • Simian Immunodeficiency Virus / immunology*
  • Vaccination / methods*
  • Vaccines, Synthetic / immunology
  • Viral Vaccines / immunology*
  • Viremia / prevention & control
  • tat Gene Products, Human Immunodeficiency Virus / immunology

Substances

  • Fusion Proteins, gag-pol
  • HIV Envelope Protein gp160
  • Vaccines, Synthetic
  • Viral Vaccines
  • gp160 protein, Human immunodeficiency virus 1
  • tat Gene Products, Human Immunodeficiency Virus