Analysis of T regulator cell surface markers and functional properties in multiple sclerosis

The relative proportions as well as cell surface and functional properties of T suppressor (T8⁺) and T helper (T4⁺) cells in peripheral blood mononuclear cells (MNCs) of MS patients were analyzed. The proportion of T8 cells compared to normal controls was suggestively lower in patients during relapses and significantly lower in those with progressive disease. The density of T8⁺ antigen on cells of MS patients with active disease as measured by median fluorescence intensity (MFI) was also decreased compared to controls and stable MS patients. Using OKT8-mAb modulated MNCs as a model, we found that reduction of T8 antigen density results in substantial discrepancies between FACS and microscope methods for enumeration of T8⁺ cells. Levels of pokeweed mitogen-induced IgG secretion by MNCs of MS patients did not correlate with proportion of T8⁺ cells within the MNCs, but rather with the functional activity of the T8⁺ cells of given individuals, as tested in an in vitro suppressor assay using constant numbers of T8⁺ cells.