Antiretroviral Therapy Suppresses RNA N6-Methyladenosine Modification in Peripheral Blood Mononuclear Cells from HIV-1-Infected Individuals.

RNA N⁶-methyladenosine (m⁶A) modification is important for regulating gene expression and innate immune responses to viral infection. HIV-1 in vitro infection induces a significant increase in m⁶A modification of cellular RNA; however, whether m⁶A levels of cellular RNA are affected by HIV-1 replication or by antiretroviral therapy (ART) in infected individuals remains unknown. Using dot blot or enzyme-linked immunosorbent assay, we measured RNA m⁶A levels of peripheral blood mononuclear cells (PBMCs) from healthy donors or HIV-1-infected individuals with or without ART. Using a reverse transcription-quantitative polymerase chain reaction array, we quantified expression levels of 84 type-I interferon (IFN-I)-responsive genes in PBMCs from some individuals of these three groups. RNA m⁶A levels in PBMCs from HIV-1 viremic patients (n = 10) were significantly higher (p ≤ .0001) compared with ART-treated individuals (n = 22) or 1.5-fold higher compared with healthy donors (n = 14). However, the increase in RNA m⁶A levels did not correlate with changes in the expression of 10 m⁶A-regulatory genes. We found significant upregulation and downregulation in the expression of several IFN-I-responsive genes from HIV-1 viremic patients (n = 4) and ART-treated patients (n = 6) compared with healthy donors (n = 5), respectively. Our results suggest that post-transcriptional m⁶A modification may contribute to the regulation of IFN-I-responsive gene expression during HIV-1 infection and ART.