Immunological Characterization of HIV and SARS-CoV-2 Coinfected Young Individuals

Abstract

While the risk of SARS-CoV-2 infection and/or COVID-19 disease progression in the general population has been largely assessed, its impact on HIV-positive individuals remains unclear. We present clinical and immunological data collected in a cohort of HIV-infected young individuals during the first wave of COVID-19 pandemic. SARS-CoV-2 RNA, virus-specific antibodies, as well as the expression of factors involved in the anti-viral immune response were analyzed. Moreover, we set up an in vitro coinfection assay to study the mechanisms correlated to the coinfection process. Our results did not show any increased risk of severe COVID-19 in HIV-positive young individuals. In those subjects who contracted SARS-CoV-2 infection, an increase in IL-10 expression and production was observed. Furthermore, in the in vitro coinfection assay, we revealed a reduction in SARS-CoV-2 replication associated to an upregulation of IL-10. We speculate that IL-10 could play a crucial role in the course of SARS-CoV-2 infection in HIV-positive individuals. These results might help defining clinical management of HIV/SARS-CoV-2 co-infected young individuals, or putative indications for vaccination schedules in this population.

Keywords: COVID-19; Calu-3; HIV; IL-10; SARS-CoV-2; children; immune response; young adult.

Scheme 1

Experimental design of the in vitro coinfection assay.

Figure 1

Immunological responses in H+/S− vs. H+/S+ individuals. (A) Plasma cytokine/chemokine concentrations (pg/mL) in H+/S− (grey bars) and H+/S+ (black bars) patients; (B) mRNA expression of genes involved in the antimicrobial immune response in unstimulated (left panel) and SARS-CoV-2 (N+S)-stimulated (right panel) PBMCs isolated from H+/S− and H+/S+ individuals; gene expression (mean values) is shown as a color scale from white to blue/black (Heatmap). Results are indicated as mean ± SEM values and statistically significant differences (p < 0.05) are indicated; * p < 0.05.

Figure 1

Immunological responses in H+/S− vs. H+/S+ individuals. (A) Plasma cytokine/chemokine concentrations (pg/mL) in H+/S− (grey bars) and H+/S+ (black bars) patients; (B) mRNA expression of genes involved in the antimicrobial immune response in unstimulated (left panel) and SARS-CoV-2 (N+S)-stimulated (right panel) PBMCs isolated from H+/S− and H+/S+ individuals; gene expression (mean values) is shown as a color scale from white to blue/black (Heatmap). Results are indicated as mean ± SEM values and statistically significant differences (p < 0.05) are indicated; * p < 0.05.

Figure 2

Immunological responses in H−/S+ vs H+/S+ individuals. (A) Plasma cytokine/chemokine concentrations (pg/mL) in H−/S+ (white bars) and H+/S+ (black bars) patients; (B) Plasma IL6/IL10 ratio in H−/S+ and H+/S+ patients; (C) mRNA expression of genes involved in the antimicrobial immune response analyzed on unstimulated (left panel) and SARS-CoV-2 (N+S)-stimulated (right panel) PBMCs isolated from H−/S+ and H+/S+ individuals; gene expression (mean values) is shown as a color scale from white to blue/black (Heatmap). Results are indicated as mean ± SEM values and statistically significant differences (p < 0.05) are indicated; * p < 0.05, ** p < 0.01.

Figure 3

IL-10 expression and production are increased in in vitro coinfection. (A) Viral load expressed as copy number of N1 and N2 genes in SARS-CoV-2 infected only Calu-3 cells (white bar) and SARS-CoV-2-infected Calu-3 cells exposed to HIV-infected PBMCs (black bar). (B) mRNA expression of IL6, IL8, IL10, IFNG, TGFβ1, and STAT3, assessed by RT-Real-Time PCR, on Calu-3 from different conditions: Calu-3 infected only with SARS-CoV-2 (S+, white bar), not-infected Calu-3 cells exposed to HIV-infected PBMCs (H+, grey bar), and Calu-3 SARS-CoV-2-infected exposed to HIV-infected PBMCs (H+/S+, black bar); (C) mRNA expression of IL6, IL8, IL10, IFNG, TGFβ1, and STAT3, assessed by RT-Real-Time PCR, on PBMCs from different conditions: not-infected PBMCs exposed to SARS-CoV-2-infected Calu-3 (S+, white bar), HIV-infected only PBMCs (H+, grey bar), and HIV-infected PBMCs exposed to SARS-CoV-2-infected Calu-3 cells (H+/S+, black bar). Results are shown as the media of the relative expression units to the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as reference gene calculated by the 2^−ΔΔCt equation. (D) Supernatant IL-10 concentrations (pg/mL) from in vitro co-cultures. Results are expressed as mean ± SEM and statistically significant differences (p < 0.05) are indicated; * p < 0.05; # p < 0.05; ### p < 0.001; #### p < 0.0001.

Figure 3

IL-10 expression and production are increased in in vitro coinfection. (A) Viral load expressed as copy number of N1 and N2 genes in SARS-CoV-2 infected only Calu-3 cells (white bar) and SARS-CoV-2-infected Calu-3 cells exposed to HIV-infected PBMCs (black bar). (B) mRNA expression of IL6, IL8, IL10, IFNG, TGFβ1, and STAT3, assessed by RT-Real-Time PCR, on Calu-3 from different conditions: Calu-3 infected only with SARS-CoV-2 (S+, white bar), not-infected Calu-3 cells exposed to HIV-infected PBMCs (H+, grey bar), and Calu-3 SARS-CoV-2-infected exposed to HIV-infected PBMCs (H+/S+, black bar); (C) mRNA expression of IL6, IL8, IL10, IFNG, TGFβ1, and STAT3, assessed by RT-Real-Time PCR, on PBMCs from different conditions: not-infected PBMCs exposed to SARS-CoV-2-infected Calu-3 (S+, white bar), HIV-infected only PBMCs (H+, grey bar), and HIV-infected PBMCs exposed to SARS-CoV-2-infected Calu-3 cells (H+/S+, black bar). Results are shown as the media of the relative expression units to the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as reference gene calculated by the 2^−ΔΔCt equation. (D) Supernatant IL-10 concentrations (pg/mL) from in vitro co-cultures. Results are expressed as mean ± SEM and statistically significant differences (p < 0.05) are indicated; * p < 0.05; # p < 0.05; ### p < 0.001; #### p < 0.0001.