Relative increase of inflammatory CD4+ T cells in the cerebrospinal fluid of multiple sclerosis patients and control individuals.

Of three patients with multiple sclerosis (MS) and two non-MS individuals a large number of CD4+ T cell clones was obtained from the cerebrospinal fluid and peripheral blood by direct limiting dilution. The CD4+ T cell clones from cerebrospinal fluid and peripheral blood lymphocytes were compared for their cytotoxic activity and lymphokine production. Cytotoxic capacity of cloned T cells was analysed with the use of anti-CD3 antibodies and target cells bearing Fc receptors for murine IgG. Recently, we demonstrated the existence of two different subsets of human CD4+ T cell clones by phenotypic and functional criteria. One type of CD4+ T cell with anti-CD3 mediated cytotoxic activity, in analogy with murine studies, is the inflammatory or TH1 subtype, the main producer of interleukin (IL-2), interferon-gamma (IFN-gamma) and tumour necrosis factor (TNF)-alpha, -beta, whereas the other type of CD4+ T cell clone lacked anti-CD3 mediated cytotoxicity and produced minimal amounts of IL-2 concomitant with reduced levels of IFN-gamma and TNF-alpha, -beta. The present study demonstrates that among three MS patients, relatively more inflammatory CD4+ T cell clones with cytotoxic activity and IFN-gamma and TNF-alpha, -beta production were derived from the cerebrospinal fluid as compared with peripheral blood lymphocytes. Also among control individuals more inflammatory CD4+ T cell clones could be obtained from the cerebrospinal fluid as from the peripheral blood. The enrichment of inflammatory CD4+ T cells, therefore, appears to be physiological rather than associated with the disease.