Cellular expression of TNF-alpha in human cytomegalovirus (HCMV) infection

Human cytomegalovirus (HCMV) belongs to the most frequent human pathogens. Even if the respective pathomorphological patterns are known in detail, the mechanisms which lead to persistence of the virus in its latent form, its reactivation as well as mechanisms of cell death in the symptomatic infection remain to be clarified. It is postulated that HCMV controls expression of TNF-alpha gene and the associated secondary inflammatory response. On the other hand, TNF-alpha has been shown in in vitro studies to represent a potential stimulator of HCMV major IE promoter. The present studies have been aimed at evaluation of TNF-alpha expression in HCMV-infected brain, liver, kidney and pancreas, obtained upon autopsy from children deceased due to an inborn HCMV infection. In situ hybridisation using digoxigenin-labelled oligonucleotide probe demonstrated the expression of TNF-alpha transcript in the liver (in macrophages and endothelial cells) and in pancreatic islets of Langerhans (in beta cells). Immunocytochemical studies aimed at detection of TNF-alpha protein in the material yielded negative results.