AUTHOR=Zhang Chuyu , Lan Yun , Li Linghua , He Ruiying , Meng Yu , Li Jian , Chen Weilie 

TITLE=HIV-1 tropism in low-level viral load HIV-1 infections during HAART in Guangdong, China

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1159763

DOI=10.3389/fmicb.2023.1159763

ISSN=1664-302X

ABSTRACT=<sec><title>Background</title><p>Since only a few studies have been conducted on the factors associated with different HIV-1 tropisms in low-level viral load HIV-1 infections in China, we investigated the sequences of HIV-1 V3 loop in prevalent HIV-1 subtypes and factors related to HIV-1 tropism and immune recovery in HIV-1 infections after 6 months of highly active antiretroviral therapy (HAART) in Guangdong, China.</p></sec><sec><title>Methods</title><p>Plasma samples with HIV-1 RNA of 400–999 copies/mL were collected. We analyzed the amino acid sequence of the V3 loop by <italic>in silico</italic> prediction algorithms. Mann–Whitney and Chi-square tests were used for statistical comparison. Furthermore, logistic regression and multiple linear regression were used, respectively, for factors associated with 351 HIV-1 tropism and immune recovery of 67 cases with continued CD4<sup>+</sup> T cell count during HAART.</p></sec><sec><title>Results</title><p>There was a lower percentage of HIV-1 R5-tropic virus in CRF01_AE (66.3%) (<italic>p</italic> &lt; 0.0001) and CRF55_01B (52.6%) (<italic>p</italic> &lt; 0.0001) compared with both CRF07_BC (96.1%) and CRF08_BC (97.4%), respectively. Compared with the R5-tropic virus, higher proportions of IIe8/Val8, Arg11/Lys11, and Arg18/His18/Lys18 were observed in the X4-tropic virus of CRF01_AE and CRF07_BC (<italic>p</italic> &lt; 0.0001). The baseline CD4<sup>+</sup> T cell count (<italic>p</italic> &lt; 0.0001) and baseline CD4<sup>+</sup> T/CD8<sup>+</sup> T ratio (<italic>p</italic> = 0.0006) of all R5-tropic infections were higher than those in the X4-tropic infection. The baseline CD4<sup>+</sup> T cell count (odds ratio [OR] 0.9963, <italic>p</italic> = 0.0097), CRF07_BC (OR 0.1283, <italic>p</italic> = 0.0002), and CRF08_BC (OR 0.1124, <italic>p</italic> = 0.0381) were associated with less HIV-1 X4-tropism. The baseline CD4<sup>+</sup> T cell count was a positive factor (<italic>p</italic> &lt; 0.0001) in the recovery of CD4<sup>+</sup> T cell count during HAART.</p></sec><sec><title>Conclusion</title><p>R5-tropism represented the majority in low-level viral load HIV-1 infections receiving HAART for more than 6 months in Guangdong, China. The baseline immune level in the HIV-1 R5-tropic infections was higher than that in the X4-tropic infections. The amino acids of the 8th, 11th, and 18th of the HIV-1 V3 loop were more variable in the X4-tropic HIV-1. CRF01_AE, CRF55_01B, and lower baseline CD4<sup>+</sup> T cell count were associated with more HIV-1 X4-tropism. The immune recovery during HAART was positively related to baseline CD4<sup>+</sup> T cell count.</p></sec>