02489nas a2200301   4500000000100000008004100001260001300042653001200055653002100067653001300088653001200101653002000113653002600133653002500159653000900184653002100193653001800214653001500232100001900247700001100266700001600277245014100293856004100434300001100475490000700486520168000493022001402173       1981                            d  c1981 Sep10aAnimals10aAnimals, Newborn10aImmunity10aleprosy10aLeukocyte Count10aLymphocyte Activation10aMycobacterium leprae10aRats10aRats, Inbred Lew10aT-Lymphocytes10aThymectomy1 aFieldsteel A H1 aSato N1 aColston M J00aRelationship between T-cell population in neonatally thymectomized Lewis rats and susceptibility to infection with mycobacterium leprae.  uhttp://ila.ilsl.br/pdfs/v49n3a07.pdf  a317-230 v493 a<p>The neonatally thymectomized Lewis rat (NTLR) is highly susceptible to infection with M. leprae. However, a significant percentage of NTLR respond to infection with M. leprae in much the same way as do intact rats, yet show no evidence of residual thymus. To determine whether there was a correlation between the number of remaining T-cells and susceptibility to infection with M. leprae, a direct fluorescent antibody test was performed using a highly specific, absorbed antithymocyte globulin labeled with fluorescein isothiocyanate. Both total circulating white blood cells and T-cells were significantly depressed in all NTLR examined. Although the greatest numbers of M. leprae were found in NTLR from the groups having the lowest percentage of circulating T-cells, these groups also contained NTLR infected with small numbers of M. leprae. The groups containing NTLR with the highest percentages of circulating T-cells also contained animals with both moderate and severe M. leprae infection. The response of cultured splenic lymphocytes from NTLR and normal rats to the T-cell mitogen concanavalin A was investigated to determine whether there was any correlation between T-cell activity and susceptibility to M. leprae infection. The mean stimulation index for normal rats was five to ten times greater than indices for NTLR, but there were no significant differences between NTLR with a well developed, generalized infection and those with a poorly developed infection. it was concluded that since there was no apparent relationship between T-cell depletion and susceptibility to infection with M. leprae, an additional, unknown mechanism was also involved.</p>
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