Transmission network characteristics based on env and gag sequences from MSM during acute HIV-1 infection in Beijing, China

Abstract

Molecular epidemiology can be used to identify human immunodeficiency virus (HIV) transmission clusters, usually using pol sequence for analysis. In the present study, we explored appropriate parameters to construct a simple network using HIV env and gag sequences instead of pol sequences for constructing a phylogenetic tree and a genetic transmission subnetwork, which were used to identify individuals with many potential transmission links and to explore the evolutionary dynamics of the virus among men who have sex with men (MSM) in Beijing. We investigated 70 acute HIV-1 infections, which consisted of HIV-1 subtype B (15.71%), the circulating recombinant forms CRF01_AE (47.14%), CRF07_BC (21.43%), CRF55_01B (1.43%), and CRF65_cpx (4.29%), and an unknown subtype (10.00%). By exploring the similarities and differences among HIV env, gag and pol sequences in describing the dynamics of the HIV-1 CRF01_AE transmission subnetwork among Beijing MSM, we found that four key points of the env sequences (strains E-2011_BJ.CY_16014, E-2011_BJ.FT_16017, E-2011_BJ.TZ_16064, and E-2011_BJ.XW_16035) contained more transmission information than gag sequences (three key points: strains G-2011_BJ.CY_16014, G-2011_BJ.FT_16017, and G-2011_BJ.XW_16035) and pol sequences (two key points: strains P-2011_BJ.CY_16014 and P-2011_BJ.XW_16035). Although the env and gag sequence results were similar to pol sequences in describing the dynamics of the HIV-1 CRF01_AE transmission subnetwork, we were able to obtain more precise information, allowing identification of key points of subnetwork expansion, based on HIV env and gag sequences instead of pol sequences. Taken together, the key points we found will improve our current understanding of how HIV spreads between MSM populations in Beijing and help to better target preventative interventions for promoting public health.

Genetic characterization of HIV-1 epidemic in Anhui Province, China

“…To date, many studies based on transmission network analysis have been implemented. Zhang et al [22] constructed a transmission network to identify individuals with many potential transmission links and to explore the evolutionary dynamics of the virus among men who have sex with men (MSM) in Beijing. Zhang et al [23] demonstrated that cross-regional HIV transmission in MSM was common and identified a key region for HIV transmission by using a transmission network.…”

Molecular epidemiology of a primarily MSM acute HIV‐1 cohort in Bangkok, Thailand and connections within networks of transmission in Asia

“…The envelope glycoprotein (encoded by env ) mediates viral entry into host cells, and though it is partially shielded by glycans from the immune response, it possesses the highest genetic diversity and evolutionary rate of any gene in the HIV‐1 genome . Understanding env ‐based networks may yield insight into viral pathogenesis, for a strain that has a high degree of connectivity may possess some advantage with respect to infectivity or fitness . Translated to approaches for vaccine design in which the HIV‐1 envelope glycoprotein is a target, trends in env ‐based transmission networks could provide more contemporaneous data to show that current vaccine candidates may still cover the majority of circulating subtypes despite increasing diversity and recombination, and could also inform selection for vaccines in the pipeline.…”

Molecular network-based intervention brings us closer to ending the HIV pandemic

“…Numerous phylogenetic studies have revealed the origins and routes of transmission of major HIV subtypes prevalent in China [51][52][53][54][55][56][57][58]. In recent years, some Chinese scholars have also used genetic surveillance or drug-resistance testing data to construct national or regional molecular networks for major HIV subtypes in China with both the above two approaches; these studies were the first attempts and explorations of molecular networks and transmission networks [59][60][61][62][63]. The 4th National HIV Molecular Epidemiological Survey revealed a full picture of the main epidemic clusters among different high-risk populations.…”