HIV-1 CRF07_BC with a Seven Amino Acid Deletion in the gag p6 Region Dominates in HIV-1-Infected Men Who Have Sex with Men in China

Abstract

We examined sequence variation in the HIV-1 gag p6 region from 27 individuals infected with HIV-1 CRF07_BC. An additional 269 gag p6 sequences of CRF07_BC from the Los Alamos National Laboratory database were also analyzed. A unique deletion of seven amino acid (aa) (p6Δ7) (aa 30-36, PIDKELY, in the HXB2 genome) was observed to exist exclusively in CRF07_BC. Indeed, 54.1% (160/296) of the CRF07_BC sequences contained the p6Δ7 mutation. The prevalence of the p6Δ7 mutation was 37.2% (29/78) and 92.3% (48/52) in CRF07_BC-infected intravenous drug users and men who have sex with men (MSM), respectively. Our results demonstrate that the p6Δ7 mutation dominates in MSM infected by HIV-1 CRF07_BC in China and suggests that this deletion could serve as a useful marker for monitoring HIV-1 evolution and epidemic. In future studies, it will be of interest to determine whether such genotypic variation influences viral replication capacity and disease progression.

HIV‐1 genotype is independently associated with immunodeficiency progression among Chinese men who have sex with men: an observational cohort study

“…A similar phenomenon has only been reported in one other case, that of CRF07_BC‐infected PWID in Taiwan . CRF07_BC viruses have a unique feature, a signature seven‐amino acid deletion in the p6 Gag protein , which results in defects in virus release, replication and infectivity . However, our preliminary data indicate that these defects are moderate and that the infection is only 20–30% less efficient than that of the wild‐type laboratory strain pNL4‐3 virus in a cell culture infectivity assay (Z. Cheng et al ., manuscript in preparation).…”

HIV-1 CRF07_BC transmission dynamics in China: two decades of national molecular surveillance

“…This indicates CRF07_BC is more likely popular among high-risk populations (MSM), thus, the resulting independent transmission cluster 07BC_N circulating in high-risk populations have a greater transmission risk. This aligns with Tang’s report that CRF07_BC contained the p6Δ7 mutation dominated in MSM in China [ 25 ]. Considering the rapid increase of 07BC_N since 2005, especially after 2010, the rapid increase trend of 07BC_N is consistent with the period of the rapid spread of CRF07_BC among MSM [ 3 , 7 ].…”

The prevalence, temporal trends, and geographical distribution of HIV-1 subtypes among men who have sex with men in China: A systematic review and meta-analysis

“…The result of our study showed CRF07_BC increased from 2004 to 2010, and then experienced slower growth, which is consistent with the evidence. A laboratory study found that in some MSM, CRF07_BC strains may significantly improve in vitro infectivity [39]. A clinical study found that after 18 months of treatment, total HIV DNA decreases more markedly in patients infected with CRF01_AE than with subtype B or CRF07_BC [40].…”