CHARACTERIZATION of HIV and SARS-CoV-2 COINFECTION: ROLE of IL-10

ABSTRACT

Background: Interaction between HIV and SARS-CoV-2 infection has not yet been fully characterized. To this purpose, an in-vitro HIV/SARS-CoV-2 coinfection assay was set up. Furthermore, the results obtained in the in-vitro model were verified in a cohort of HIV/SARS-CoV-2 coinfected young individuals. Methods: We designed an in-vitro SARS-CoV-2/HIV coinfection. We challenged PBMCs derived from 10 healthy volunteers with 1 ng/1×106 cells of HIV-1BaL and subsequently co-cultured them with a human lung epithelial cell line (CaLu3) infected with SARS-CoV-2 at 0.015 MOI. At 96 hours post HIV-1 infection, both PBMCs and CaLu3 cells were harvested for mRNA expression and proteomic analysis. Furthermore, we enrolled 85 ART-treated HIV-vertically transmitted patients (mean age 22.4 years) followed at the Unit of Pediatric Infectious Diseases, Sacco Hospital in Milan, Italy. Real-time PCR was performed to detect SARS-CoV-2 and plasma samples were tested for anti-SARS-CoV-2-specific IgG (Euroimmun Kit). The subjects who contracted SARS-CoV-2 infection (H+/S+) were compared to the HIV-positive, SARS-CoV-2 negative ones (H+/S-) and to a cohort of SARS-CoV-2 positive, HIV-negative age-matched patients (H-/S+, mean age 22.8 years). We evaluated mRNA expression of factors involved in the anti-viral immune response on PBMCs upon stimulation with SARS-CoV-2 antigens (Quantigene Plex assay) and secreted cytokines/chemokines on plasma (Multiplex Cytokine Array). Results: We observed a significant reduction of SARS-CoV-2 replication on CaLu3 cells when exposed to HIV-pre-infected PBMCs in-vitro. IL-10 expression and production were significantly higher in the coinfected condition, in both CaLu3 cells and PBMCs. The upregulation of IL-10 was associated to higher expression levels of STAT3. In the HIV-vertically transmitted cohort, 4 out of 85 subjects contracted SARS-CoV-2 infection (H+/S+). All H+/S+ patients were asymptomatic. Similarly to the data obtained in-vitro, a significant increase in both expression and production of IL-10 emerged in comparison to H+/S-and H-/S+. Conclusion: In-vitro, a dampening in SARS-CoV-2 replication, along with a higher IL-10 mRNA expression and production, have been observed in the HIV/SARS-CoV-2 coinfected condition. Presumably, IL-10 exerted its activity through the STAT3 pathway. These results were confirmed in HIV/SARS-CoV-2 coinfected subjects in which an upregulation of IL-10 was observed. Our data might be useful defining HIV/SARS-CoV-2 coinfected young individuals pathogenesis.