Interferon-gamma secretion by in vivo activated cytotoxic T lymphocytes from the blood and cerebrospinal fluid during mumps meningitis.

Functional studies of cerebrospinal fluid T lymphocytes during acute viral infections of the nervous system are rare. Recently, we had the opportunity to investigate the requirements for interferon-gamma (IFN-gamma) production of human in vivo activated (primary) cytotoxic T lymphocytes (CTL) generated during acute viral meningitis. Two HLA-B7-restricted, CD4-, CD8+ CTL clones from cerebrospinal fluid of one patient with mumps meningitis were studied. Although lytic activity was restricted by HLA-B7, the clones produced similar amounts of IFN-gamma when stimulated with HLA-matched and mismatched mumps virus-infected target cells. In addition, peripheral blood mononuclear cells of infected patients secreted significant amounts of IFN-gamma when incubated with autologous or allogeneic (HLA-A/B-mismatched) mumps virus-infected target cells. T cells capable of lytic activity and IFN-gamma secretion could only be isolated from venous blood during the initial phase of the infection. We suggest that the ability of human in vivo activated CTL to secrete INF-gamma early during the course of inflammation and in a HLA-unrestricted fashion is important for the elimination of viruses invading the central nervous system.