A DNA-based candidate HIV vaccine delivered via in vivo electroporation induces CD4 responses toward the α4β7-binding V2 loop of HIV gp120 in healthy volunteers

Abstract

Administration of a clade C/B' candidate HIV-1 DNA vaccine, ADVAX, by in vivo electroporation (EP) was safe and more immunogenic than intramuscular administration without EP. The breadth and specificity of T-cell responses to full-length Env were mapped. Responses to multiple Env regions were induced, with most focusing on V3/C4 and V2 regions, including the α4β7 integrin-binding domain. The breadth of responses induced by this DNA vaccine regimen was comparable to that of viral-vectored vaccine regimens.

Fig 1

Vaccination-induced Env pool-specific responses in CD4⁺ CD8⁻ CD3⁺ cells illustrated using a combinatorial Boolean gate of IFN-γ-, TNF-α-, and IL-2-producing populations (red) overlaid onto memory (CD45RO⁺ CD27⁺) and functional phenotypes as evaluated by polychromatic flow cytometry (representative example).

Fig 2

Locations of targeted regions (red) superimposed on a schematic gp120 backbone. The α4β7 integrin binding motif is highlighted in blue. (Adapted from Retrovirology [19] with permission of the publisher.)