Immunoglobulin genes and the acquisition of HIV infection in a randomized trial of recombinant adenovirus HIV vaccine

• This study involved the participants in an HIV1 vaccine efficacy trial (Step trial).
• The aim was to identify the host genetic correlates of HIV1 acquisition.
• Participants were genotyped for several FcγRIIa, FcγRIIIa, GM, and KM alleles.
• Certain genotypic combinations were significantly associated with HIV1 acquisition.

Our knowledge of the host genetic factors that contribute to the acquisition of HIV infection is limited. To identify the host genetic correlates of HIV1 acquisition, we genotyped 777 participants of a randomized trial of recombinant adenovirus HIV1 vaccine for Fcγ receptor IIa (FcγRIIa), FcγRIIIa, and several GM and KM alleles—genetic markers of immunoglobulin γ and κ chains, respectively. None of the genotypes by itself was significantly associated with the acquisition of HIV1 infection. However, particular combinations of GM and KM as well as those of GM and FcγRIIIa loci were significantly associated with the acquisition of HIV1 infection epistatically: KM1/3-GM3/17 (interaction p=0.0246; FDR=0.2952), KM1/3-GM5/21 (interaction p=0.0016; FDR=0.0960), and GM23+/−FcγRIIIa (interaction p=0.0060; FDR=0.1200). These results suggest the involvement of GM, KM, and FcγRIIIa loci in the acquisition of HIV infection. Additional studies are warranted.