Replication of measles virus in human lymphocytes

Replication of measles virus was restricted in human peripheral blood mononuclear cells (PBMC). However, in in vitro-infected, unstimulated cells, active synthesis of viral RNA and proteins occurred, while the release of infectious virus could not be detected. Stimulation with PHA caused a productive infection cycle comparable to the lytic infection. Replication of viral RNA was demonstrated in both T and B cells, and in both OKT4+- and OKT8+-depleted T cell subsets. The presence of measles virus RNA was detected in PBMC isolated from measles patients, and the production of the immunoreactive hemagglutinin protein was defective in these cells.