The Influence of HIV-1 Subtype in the Response to Therapeutic Dendritic Cell Vaccine

In the present study, we investigated the influence of HIV-1 subtype in the response to the dendritic cell (DC) therapeutic vaccine for HIV. HIV-1 viral load and TCD8+/TCD4+ cell counts for up to 48 weeks after vaccination. Out of 19 immunized subjects, 13 were infected by subtype B, 5 by subtype F, and 1 by subtype D. Overall, 42.1% (8/19) achieved a viral load decline of ≥ 1 log(10) sustained up to 48 weeks after immunization. Such magnitude of viral load drop was seen in 80% (4/5) of subtype F infected patients, and in 23.0% (3/13) of the subtype B infected ones (p=0.08). Moreover, mean viral load decline was 1.32 log(10), for subtype F infected individuals compared to 0.5 log(10) among subtype B infected patients (p=0.01). The variation in TCD4+ cell count was not related to HIV-1 subtype. Larger studies are necessary to confirm the efficacy of this immunotherapy and the differential response according to the background genetic diversity of HIV-1.