Molecular signatures and causal factors underlying latent cytomegalovirus infection among people living with HIV (PLHIV)

Abstract

Abstract CMV seropositivity contributes to medical complications in people living with HIV (PLHIV). This study provides a comprehensive evaluation of how CMV seropositivity shapes the immune system of 1,887 PLHIV, by utilizing multi-omics and deep immune phenotyping datasets. The study measured the immune cell profiles from whole blood, and the cytokine production of PBMCs exposed to various ex-vivo stimuli. We observed an increase in pro-inflammatory cytokine production of circulating immune cells and differences in phenotype of innate-like lymphocyte populations associated with CMV seropositivity. This study also measured 5-omics layers, including genomics, DNA methylation, transcriptomics, and plasma protein and metabolites. The DNA methylome and transcriptome demonstrated prominent CMV-induced signatures related to immune functions in PLHIV. Particularly, high FCRL6 expression is a promising biomarker for immune activation, underlined by the demethylation of FCRL6 and up-regulation of gene expression and plasma protein concentrations in CMV-seropositive PLHIV. Host genetics-driven elevation in both gene and protein expression of FCRL6 was also associated with latent CMV infection. A significant CMV-seroprevalence locus was associated with cytokine production capacity and protein abundance. Mendelian randomization analyses demonstrated a causal relationship between elevated FCRL6 expression and CMV seropositivity.