GSE173290
Comparative transcriptome analysis implicates IL1R8-associated upregulation of myeloid leukocyte pathways in latent HCMV infection
Latent human cytomegalovirus (HCMV) in myeloid cells can be reactivated during cell differentiation and by inflammatory mediators. Expression level of immune regulator IL1R8 has been associated with the differentiation status of myeloid cells. As far, little is known about the role of IL1R8 in the association between reactivation of latent HCMV and differentiation of myeloid cells. To gain additional insights into IL1R8 and latency, a comparative transcriptome analysis was carried out through a unique bioinformatics approach that integrated IL1R8-correlated genes with differentially expressed genes to identify IL1R8-associated significant pathways. The Metascape pathway tool was utilized to perform enrichment analysis. The initial analysis revealed a significant inverse correlation between IL1R8 and viral counts (r = -0.42, z-score = -4.69) at single cell level in HCMV-infected monocytes at 4-14 days postinfection. In contrast to the majority of pathway analysis studies presenting unilateral up- or down-regulation, the current study discovered a number of bilaterally regulated key immune pathways in both lytic and latent infections. Notably, a ~3-fold predominant downregulation of the high-level adaptive immune system pathway was followed by a modestly predominant downregulation of mid-level Lymphocyte and low-level T cell activation pathways in latent infection. More interestingly, a unilateral upregulation pattern was identified exclusively in latent infection for Myeloid leukocyte activation, differentiation, and migration, in which upregulated genes were in concord with IL1R8 negatively correlated genes. The findings in the present study provided a comprehensive view of immunological alterations and a better understanding on the potential role of IL1R8 in the association between HCMV reactivation and myeloid cell differentiation in HCMV infection. The current study, for the first time, presented unique evidence supportive of a IL1R8-associated unilateral upregulation of myeloid leukocyte pathways in latent infection. Overall design: THP-1 cells were infected with HCMV Towne strain (or Mock) at a multiplicity of infection (MOI) of 5. To ensure a latent infection, total RNA from THP-1 cells was extracted at day 4 post-infection without any differentiation stimulation (namely HCMV and Mock samples) using Trizol reagent (Invitrogen, USA).