“MicroRNA expression profiling of human milk derived exosomes identifies miR-630 and miR-378g as biomarkers in HIV-1 infected women”

Abstract Background: Despite the use of antiretroviral therapy (ART) in HIV-1 infected mothers approximately 5% of new HIV-1 infections still occur in breastfed infants annually which warrant for the development of new additional strategies to completely prevent new HIV-1 infections in infants. Human Milk (HM) exosomes are highly enriched in maternal microRNAs (miRNAs) which after ingestion and absorption play an important role in neonatal immunity. Although, HM exosomes from healthy donors are known to inhibit HIV-1 transmission; the effect of HIV-1 on HM exosomal miRNA signatures remains unknown. In the present study, HM derived exosomal miRNA profiles were investigated in HIV-1 infected lactating women. Methods: First week postpartum HM exosomes were purified from uninfected control and HIV-1 infected mothers (n=36), processed for RNA extraction and subjected to miRNA expression profiling by NanoString technology. The data were analyzed, and targets were predicted. Results: We describe that HIV-1 perturbed the differential expression pattern of 19 miRNAs (13 up and 6 downregulated) in HIV-1 infected women compared to healthy controls. DIANA-miR functional Pathway analyses revealed that multiple biological pathways are involved including Cell cycle, Pathways in Cancer, TGF-β signaling, FoxO signaling, Fatty Acid Biosynthesis, p53 signaling and Apoptosis. Further, the receiver operating characteristics (ROC) curve analyses of two of the identified miRNAs, miR-630 and miR-378g for separating HIV-1 infected women from healthy controls yielded areas under the ROC curves of 0.82 (95% CI= 0.67 to 0.82) and 0.83 (95% CI= 0.67 to 0.83), respectively highlighting their potential to serve as biomarkers of HIV-1 infection in women. Conclusions: Our studies provide new information that HIV-1 perturbs the expression levels of HM derived exosomal miRNAs in lactating women. The stability of HM exosomes at room temperature raises the possibility of their utility in HIV-1 screening prior to HIV-1 specific testing in countries like Nigeria. Further, our data may also contribute to the development of new therapeutic strategies in prevention of mother-to-child transmission (MTCT) of HIV-1 in infants.