Presence of HIV-1 G-to-A mutations linked to APOBEC editing is more prevalent in non-B HIV-1 subtypes and is associated with lower HIV-1 reservoir

Abstract

Objectives: APOBEC3 editing activity contributes to sequences variation and viral diversification. We aimed to characterize virological and clinical factors associated with G-to-A mutations and stop codons in the HIV-1 reservoir, markers of APOBEC3 footprints, in order to better understand HIV-1 diversity among virologically suppressed HIV-1-infected patients.

Methods: Immuno-virological and clinical factors were compared between 92 patients harbouring G-to-A mutations and stop codons (APOBEC+) in the reverse transcriptase gene and 92 patients without G-to-A mutations (APOBEC-) and stop codons in their DNA genotypes.

Results: Patients were predominantly men (74.5%) and were mostly infected by B-subtype (69.0%), with 44.1% and 55.9% in APOBEC+ and APOBEC- groups, respectively. At time of HIV DNA genotypes, the total cell-associated HIV-1 DNA load was 2.34 log10 copies/106 cells (IQR 1.85-2.67) and 33.2% of them had a detectable ultrasensitive plasma viral load. Hypermutated sequences were identified in 28.2% of the APOBEC+ group. The median total cell-associated HIV-1 DNA level was significantly lower in APOBEC+ than APOBEC- group: 2.13 log10 copies/106 cells (IQR 1.60-2.60) versus 2.52 log10 copies/106 cells (IQR 2.19-2.71) (P < 0.001), respectively. Presence of G-to-A mutations and stop codon was independently associated with HIV-1 subtype non-B (P = 0.017).

Conclusions: These results show an independent association between the presence of G-to-A mutations and stop codons with HIV-1 subtype non-B and low proviral DNA that could be explained by the APOBEC3 footprints and restriction of DNA synthesis and integration. However, further investigations are needed to study the contribution of Vif amino acid variability among HIV-1 subtypes.