Survey of cellular immune responses to human cytomegalovirus infection in the microenvironment of the uterine –placental interface

AbstractCongenital human cytomegalovirus (HCMV) infection is a leading cause of birth defects, yet there are no established treatments for preventing maternal –fetal transmission. During first trimester, HCMV replicates in basal decidua that functions as a reservoir for virus and source of transmission to the attached placenta and fetal hemiallograft but also contains immune cells, including natural killer cells, macrophages, and T cell subsets, that re spond to pathogens, protecting the placenta and fetus. However, the specific cellular and cytokine responses to infection are unknown, nor are the immune correlates of protection that guide development of therapeutic strategies. Here we survey immune cell phenotypes in intact explants of basal decid ua infected with a clinical pathogenic HCMV strain ex vivo and identify specific changes occurring in response to infection in the tissue environment. Using 4-color immunofluorescence microscopy, we found that at 3 days postinfection, virus replicates in decidual stromal cells and epithelial cells of endometrial glands. Infected cells and effector memory CD8+ T cells (TEM) in contact with them make IFN-γ. CD8+ TEM cells produce granulysin and cluster at sites of infection in decidua and the epithelium of endometrial glands. Quantification indicated expansion of two immune cell subtypes—CD8 + TEM cells and, to a lesser extent, iNKT cells. Approximately 20% of immune cells were found in pairs in both control and infected decidu...
Source: Medical Microbiology and Immunology - Category: Microbiology Source Type: research