02114nas a2200397   4500000000100000008004100001260001300042653001500055653001000070653000900080653001900089653001800108653001000126653001100136653001900147653001100166653002100177653002100198653001200219653002600231653001600257653001600273653000900289653001600298653002400314100001300338700001600351700001400367700001300381700001600394245012300410300001100533490000700544520115100551022001401702       1987                            d  c1987 Jun10aAdolescent10aAdult10aAged10aAutoantibodies10aCell Division10aChild10aFemale10aFlow Cytometry10aHumans10aImmune Tolerance10aImmunoglobulin G10aleprosy10aLymphocyte Activation10aLymphocytes10aLymphokines10aMale10aMiddle Aged10aPhytohemagglutinins1 aKerr M A1 aHussein Y M1 aPotts R C1 aBeck J S1 aSheriff M M00aCharacterization of a factor in leprosy serum that inhibits the growth of mitogen-stimulated normal human lymphocytes.  a117-230 v613 a<p>A factor that inhibits the growth of mitogen-stimulated lymphocytes from normal donors has been detected in the sera of patients with chronic leprosy. The inhibitory activity was detected with similar frequency in patients with tuberculoid or lepromatous leprosy, although higher levels of activity were detected in the latter. The factor reduced the growth in volume of the lymphocytes in the first 24 hr after stimulation, the synthesis of RNA during the first 3 days of culture and the replication of DNA in 72-hr cultures. All the inhibitory activity co-purified with IgG on gel filtration, ammonium sulphate fractionation and ion exchange chromatography. The activity was stable to heating at 56 degrees but labile at 100 degrees and was absorbed from serum or from purified IgG preparations by staphylococcal protein A. On gel filtration of the sera on Sephadex G-200, none of the activity appeared in the void volume, indicating that it is not due to immune complexes. We conclude that the activity is due to an IgG antibody and suggest that it is an autoantibody since the sera inhibited the growth of all donor lymphocytes tested.</p>  a0019-2805