01752nas a2200277   4500000000100000008004100001260001300042653002400055653002000079653001900099653001100118653002200129653001200151653002600163653001600189653002500205653001700230653001500247100001100262700001200273245012300285300001100408490000700419520103400426022001401460       1980                            d  c1980 Sep10aAntigens, Bacterial10aCells, Cultured10aConcanavalin A10aHumans10aImmunosuppression10aleprosy10aLymphocyte Activation10aLymphocytes10aMycobacterium leprae10aTime Factors10aTuberculin1 aNath I1 aSingh R00aThe suppressive effect of M. leprae on the in vitro proliferative responses of lymphocytes from patients with leprosy.  a406-140 v413 a<p>Peripheral blood lymphocytes from sixty leprosy patients and eight healthy contacts known to be responsive to M. leprae, were stimulated in vitro with concanavalin A (Con A) or PPD alone or in combination with autoclaved, whole M. leprae. Time kinetics and the percentage of inhibition induced by M. leprae differed in the two disease groups and contacts. Antigen-generated suppression of Con A-stimulated lymphocyte transformation was observed on day 4 in seventeen of twenty-one (80%) tuberculoid patients and six of seventeen (35.3%) untreated lepromatous patients. Healthy contacts and 53% lepromatous individuals showed enhanced Con A responses in the presence of antigen. On prolongation of antigen presence to 6 days, a marginal effect was noted in the tuberculoid group. In contrast, all healthy individuals and some lepromatous patients showed increased inhibition of Con A responses. M. leprae antigens showed uniform inhibition of PPD-induced 3H-thymidine incorporation in leprosy patients and healthy contacts.</p>  a0009-9104