Human immunodeficiency virus type 1 V2-deleted envelope glycoprotein (DeltaV2Env)

The Human immunodeficiency virus type 1 V2-deleted envelope glycoprotein (DeltaV2Env) is a genetically engineered variant of the HIV-1 envelope (Env) protein, most commonly a trimeric gp140 form, in which the second variable loop (V2) has been removed [1, 5]. In its native state, the HIV-1 Env protein is a Type I membrane glycoprotein that mediates viral entry by binding to the CD4 receptor and chemokine coreceptors such as CCR5 or CXCR4 [15, 17]. The V2 loop is a highly flexible and glycosylated region that often shields functionally critical and conserved epitopes from immune recognition [17, 20]. Deletion of the V2 loop (DeltaV2) is intended to stabilize the envelope trimer and increase the accessibility of these shielded 'cryptic' epitopes, such as the coreceptor binding site, to induce more potent and cross-reactive neutralizing antibodies [11, 13]. As a therapeutic and prophylactic target, DeltaV2Env is primarily used as an immunogen in vaccine candidates, such as those evaluated in the ISS P-002 clinical trials, often in conjunction with the HIV-1 Tat protein [5, 6]. While vaccines utilizing DeltaV2Env have shown success in eliciting neutralization against certain sensitive viral strains in phase I trials, achieving broad-spectrum efficacy against a wide range of diverse primary HIV-1 isolates remains a significant challenge in its development [1, 4].

Other names

DeltaV2 EnvΔV2 EnvV2-deleted HIV-1 Envgp140 DeltaV2V2-loop deleted HIV-1 envelope protein

As a vaccine immunogen, the protein elicits a humoral and cellular immune response by presenting conserved and normally shielded viral epitopes to the immune system, thereby inducing the production of neutralizing antibodies and activating T-cells to block viral entry and dissemination [5, 10, 11].