[HTML][HTML] HIV-1 CD4-induced (CD4i) gp120 epitope vaccines promote B and T-cell responses that contribute to reduced viral loads in rhesus macaques

MA Thomas, I Tuero, T Demberg… - Virology, 2014 - Elsevier
MA Thomas, I Tuero, T Demberg, DA Vargas-Inchaustegui, T Musich, P Xiao, D Venzon…
Virology, 2014Elsevier
To target the HIV CD4i envelope epitope, we primed rhesus macaques with replicating Ad-
rhFLSC (HIV-1 BaL gp120 linked to macaque CD4 D1 and D2), with or without Ad-SIVgag
and Ad-SIVnef. Macaques were boosted with rhFLSC protein. Memory T-cells in PBMC,
bronchoalveolar lavage and rectal tissue, antibodies with neutralizing and ADCC activity,
and Env-specific secretory IgA in rectal secretions were elicited. Although protective
neutralizing antibody levels were induced, SHIV SF162P4 acquisition following rectal …
Abstract
To target the HIV CD4i envelope epitope, we primed rhesus macaques with replicating Ad-rhFLSC (HIV-1BaLgp120 linked to macaque CD4 D1 and D2), with or without Ad-SIVgag and Ad-SIVnef. Macaques were boosted with rhFLSC protein. Memory T-cells in PBMC, bronchoalveolar lavage and rectal tissue, antibodies with neutralizing and ADCC activity, and Env-specific secretory IgA in rectal secretions were elicited. Although protective neutralizing antibody levels were induced, SHIVSF162P4 acquisition following rectal challenge was not prevented. Rapid declines in serum ADCC activity, Env-specific memory B cells in PBMC and bone marrow, and systemic and mucosal memory T cells were observed immediately post-challenge together with delayed anamnestic responses. Innate immune signaling resulting from persisting Ad replication and the TLR-4 booster adjuvant may have been in conflict and reoriented adaptive immunity. A different adjuvant paired with replicating Ad, or a longer post-prime interval allowing vector clearance before boosting might foster persistent T- and B-cell memory.
Elsevier