Systemic immunization with an ALVAC-HIV-1/protein boost vaccine strategy protects rhesus macaques from CD4+ T-cell loss and reduces both systemic and mucosal simian-human immunodeficiency virus SHIVKU2 RNA levels

J Virol. 2006 Apr;80(8):3732-42. doi: 10.1128/JVI.80.8.3732-3742.2006.

Abstract

Transmission of human immunodeficiency virus type 1 (HIV-1) occurs primarily via the mucosal route, suggesting that HIV-1 vaccines may need to elicit mucosal immune responses. Here, we investigated the immunogenicity and relative efficacy of systemic immunization with two human ALVAC-HIV-1 recombinant vaccines expressing Gag, Pol, and gp120 (vCP250) or Gag, Pol, and gp160 (vCP1420) in a prime-boost protocol with their homologous vaccine native Env proteins. The relative efficacy was measured against a high-dose mucosal exposure to the pathogenic neutralization-resistant variant SHIV(KU2) (simian-human immunodeficiency virus). Systemic immunization with both vaccine regimens decreased viral load levels not only in blood but unexpectedly also in mucosal sites and protected macaques from peripheral CD4+ T-cell loss. This protective effect was stronger when the gp120 antigen was included in the vaccine. Inclusion of recombinant Tat protein in the boosting phase along with the Env protein did not contribute further to the preservation of CD4+ T cells. Thus, systemic immunization with ALVAC-HIV-1 vaccine candidates elicits anti-HIV-1 immune responses able to contain virus replication also at mucosal sites in macaques.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • AIDS Vaccines / immunology*
  • Animals
  • CD4 Lymphocyte Count*
  • HIV Antibodies / blood
  • HIV-1 / immunology*
  • HIV-1 / isolation & purification
  • Immunization, Secondary
  • Macaca mulatta
  • RNA, Viral / analysis*
  • Research Design
  • Simian Immunodeficiency Virus / immunology*
  • Simian Immunodeficiency Virus / isolation & purification
  • Viral Load
  • Viremia / prevention & control

Substances

  • AIDS Vaccines
  • HIV Antibodies
  • RNA, Viral
  • human immunodeficiency virus type 1 Tat vaccine