Background
Cytomegalovirus (CMV) is a widespread herpesvirus associated with inflammation and inflammation-related disorders, including cardiovascular disease (CVD). Among people with HIV (PWH), who have a two-fold increase in CVD risk compared to people without HIV (PWoH), latent CMV is nearly universal, and CMV reactivation from latency occurs more frequently, but if and how CMV reactivation contributes to elevated CVD risk in PWH is unclear.
Methods
Bulk RNA sequencing was performed on monocyte-derived macrophages (MDMs) that were differentiated from monocytes of CMV-seropositive (CMV+) PWoH (n=3M,2F), CMV-seronegative (CMV-) PWoH (n=4M,2F), or CMV+ PWH (n=11M,2F), using autologous serum, a model that preserves the influence of systemic biomarkers found in vivo. Pathway and gene set enrichment analyses were used to compare the MDM transcriptomes with previously published datasets from CVD or in vitro CMV infection. Transcription of CMV genes in MDMs was measured by PCR.
Results
When compared to MDMs of CMV- PWoH, we found that over 30% of the differentially upregulated genes in MDMs of CMV+ PWH overlapped with the differentially upregulated genes of MDMs from CMV+ PWoH, indicating a strong influence of CMV in the HIV-associated MDM transcriptome. CMV-related genes were significantly enriched for lipid and cholesterol synthesis pathways and included FDFT1. In datasets of in vitro CMV infection, FDFT1 expression was associated with productive CMV infection. Despite no clear evidence of viral reactivation in the MDMs, consistent with the low prevalence of latent CMV in circulating monocytes of PWoH, the expression of known CMV activators was enriched while the expression of known CMV repressors was reduced in CMV+ MDMs, suggesting that MDMs from people with CMV are transcriptionally permissive for CMV replication. Finally, a gene set of the top 100 most significantly upregulated genes in MDMs from CMV+ PWoH was enriched in bulk tissue from atherosclerotic plaques compared to peripheral blood cells (NES=1.943, Padj=1.31×10-3) and among macrophages isolated from ruptured atherosclerotic plaques compared to those from stable plaques (NES=1.644, Padj=3.79×10-5), consistent with a proatherogenic role for MDMs in people with CMV.
Conclusions
Our findings link an enrichment in cholesterol biosynthesis pathways in MDMs to CMV infection, HIV, and CVD, and suggest that PWH with CMV may have more atherosclerosis in part due to increased CMV activity in macrophages that infiltrate vascular tissues.
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