HIV infection and cardiovascular disease have both shared and distinct monocyte gene expression features: Women's Interagency HIV study

Abstract

Persistent inflammation contributes to the development of cardiovascular disease (CVD) as an HIV-associated comorbidity. Innate immune cells such as monocytes are major drivers of inflammation in men and women with HIV. The study objectives are to examine the contribution of circulating non-classical monocytes (NCM, CD14dimCD16+) and intermediate monocytes (IM, CD14+CD16+) to the host response to long-term HIV infection and HIV-associated CVD. Women with and without chronic HIV infection (H) were studied. Subclinical CVD (C) was detected as plaques imaged by B-mode carotid artery ultrasound. The study included H-C-, H+C-, H-C+, and H+C+ participants (23 of each, matched on race/ethnicity, age and smoking status), selected from among enrollees in the Women's Interagency HIV Study. We assessed transcriptomic features associated with HIV or CVD alone or comorbid HIV/CVD comparing to healthy (H-C-) participants in IM and NCM isolated from peripheral blood mononuclear cells. IM gene expression was little affected by HIV alone or CVD alone. In IM, coexisting HIV and CVD produced a measurable gene transcription signature, which was abolished by lipid-lowering treatment. In NCM, versus non-HIV controls, women with HIV had altered gene expression, irrespective of whether or not they had comorbid CVD. The largest set of differentially expressed genes was found in NCM among women with both HIV and CVD. Genes upregulated in association with HIV included several potential targets of drug therapies, including LAG3 (CD223). In conclusion, circulating monocytes from patients with well controlled HIV infection demonstrate an extensive gene expression signature which may be consistent with the ability of these cells to serve as potential viral reservoirs. Gene transcriptional changes in HIV patients were further magnified in the presence of subclinical CVD.

Fig 1. Results for intermediate monocyte analysis.

A. Schematic of study design showing five comparisons. HIV(H) + or—designates presence or absence of HIV infection. CVD(C) + or—designates presence of absence of cardiovascular disease. C+ groups were further stratified according to lipid lowering treatment (LLT) use. B. Volcano plots for differential gene expression analysis in comparisons of H+C-, H-C+ and H+C+ versus H-C-, as well as comparisons of H+C+LLT- and H+C+LLT+ versus H-C-. Red genes indicate significance by FDR < 0.05 and |log₂ fold-change|>1(S2 Table). C. Heatmap showing expression of top up- and down-regulated differentially expressed genes(DEGs) found in women with H+C+LLT- versus H-C- and their correlation with plasma HIV RNA (Viral load) and CD4+ T cell count (CD4 count). D. Top significantly activated pathways predicted by the fold change of DEGs found in H+C+LLT- vs. H-C- comparison (S2 Table), using ingenuity pathway analysis.

Fig 2. Results for non-classical monocyte analysis.

A. Venn Diagram of differential expression gene (DEGs) lists for the three major comparisons, all contrasted versus HIV(H)-CVD(C)- control group. B. Volcano plots for differential gene expression analysis in comparisons of H+C-, H-C+ and H+C+ versus H-C-, as well as comparisons of H+C+LLT- and H+C+LLT- versus H-C-. Red genes indicate significance by FDR < 0.05 and |log₂ fold-change |>1(S4 Table). C-D. Heatmap showing expression of top up- and down-regulated DEGs found in women with H+C+ (C) and women with H+C-(D) vs. H-C- and their correlation with HIV RNA (Viral load) and CD4+ T cell count (CD4 count). E. Top significantly activated or suppressed pathways predicted by the fold change of DEGs found in H+C- or H+C+ vs. H-C- comparison (S4 Table), using ingenuity pathway analysis.

Fig 3. Weighted gene co-expression network analysis results in non-classical monocyte (NCM).

A. Comparison of module eigenvalues (MEs) of salmon module and expression profiles of 22 salmon module genes in NCM by HIV and CVD status. B. Comparison of module eigenvalue of magenta module and expression profiles of 70 magenta module genes in NCM by HIV and CVD status. C. Spearman correlation between MEs of all gene modules identified in NCM, and CVD- or HIV-related clinical features.