Infection of human thymic epithelial cells by human cytomegalovirus and other viruses: effect on secretion of interleukin 1-like activity.

Cultures of human thymic epithelial (TE) cells are able to produce a interleukin 1 (IL-1) like activity. This IL-1 activity can be detected either using mouse thymocytes in a traditional IL-1 assay, or using thymic lymphocytes obtained from cases of pediatric cardio-vascular surgery. Production of IL-1 activity by TE cells was found to be maximal between 3 and 4 weeks after culture initiation. Human thymocytes worked best as targets in an IL-1 assay, when these cells were derived from donors younger than 1 year of age. Infection of human TE cells by any of human cytomegalovirus, herpes simplex virus type 2, adenovirus 7, Coxsackie B1, and respiratory syncytial virus led to marked reductions in the ability of these cells to secrete measurable IL-1 activity. In the case of TE cells infected by cytomegalovirus, respiratory syncytial virus, and Coxsackie B1, this abrogation of production of IL-1 activity occurred in the absence of any obvious virus-induced cytopathic effect.