A Survey of Intraocular Expression of Immune Response Genes During Onset and Progression of Experimental Mouse Cytomegalovirus (MCMV) Retinitis in Mice with Retrovirus-induced Immunosuppression (MAIDS)

Abstract

Purpose : To study the unique pathophysiology of AIDS-related cytomegalovirus retinitis, we developed an experimental mouse model of MCMV retinitis using mice with MAIDS. We have previously used this mouse model to identify immunologic events that contribute to the onset and progression of retinitis that occurs within MCMV-infected eyes of mice during MAIDS. These have included studies of individual Th1 and Th2 cytokines, suppressor of cytokine signaling proteins, and cell death pathways. To validate and further expand our knowledge of host immunologic factors that are stimulated during the pathogenesis of MAIDS-related MCMV retinitis, we used Nanostring’s nCounter® Analysis System technology to profile the mRNA expression of 541 immunology-related genes simultaneously within the ocular compartment of MCMV-infected eyes during retinitis development.

Methods : The left eyes of groups of C57BL/6 mice with MAIDS susceptible to MCMV retinitis were injected subretinally with MCMV. Right eyes were injected with maintenance medium only (control). At 3, 6, and 10 days postinfection (dpi), left and right eyes (n = 5 – 9 mice per group) were collected and individually subjected to mRNA extraction. Following pooling of mRNA from MCMV-infected eyes and pooling of mRNA from uninfected control eyes, mRNAs were analyzed using Nanostring’s Mouse Immunology Panel. Nanostring nSolver Software^TM was used to normalize gene expression across samples and calculate fold-change differences for mRNAs of MCMV-infected eyes versus uninfected control eyes.

Results : Of the 541 immunology-related genes analyzed, 203, 419, and 441 showed stimulated mRNA expression at 3, 6, and 10 dpi, respectively. At 10 dpi at time of MCMV retinitis development, 15 of the 441 genes were especially remarkable showing a >100-fold increase in mRNA expression. These included genes that encode for proteins associated with the function of macrophages, natural killer cells, the complement system, and cytokine signaling.

Conclusions : MCMV-infected eyes of MAIDS mice showed a progressive and surprisingly robust stimulation of immunology-related genes during onset and development of MCMV retinitis. These findings open new and unexpected avenues of exploration of the pathophysiology of AIDS-related cytomegalovirus retinitis.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.