01743nas a2200277   4500000000100000008004100001260001300042653001200055653002600067653001500093653002300108653001200131653000900143653002500152653002100177100001600198700001300214700001300227700001100240245008000251856008800331300001000419490000700429520101500436022001401451       1980                            d  c1980 Aug10aAnimals10aAntibodies, Bacterial10aArmadillos10aBacterial Vaccines10aleprosy10aMice10aMycobacterium leprae10aSodium Hydroxide1 aShepard C C1 aDraper P1 aRees R J1 aLowe C00aEffect of purification steps on the immunogenicity of Mycobacterium leprae.  uhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2041605/pdf/brjexppathol00118-0033.pdf  a376-90 v613 a<p>In studies aimed at the development of an antileprosy vaccine for use in man, Mycobacterium leprae suspensions were prepared from livers of experimentally infected armadillos. The 2 methods of purification in chief use, carried out after irradiation of the tissue with 2.5 megarads of gamma irradiation from 60Co, involved treatment with 0.1N NaOH for 2 h at room temperature, trypsin and chymotrypsin digestion for 24h at 37 degrees, and separation in a 2-phase liquid polymer (dextran:polyethylene glycol) system. All vaccines were autoclaved and injected intradermally in mice. Earlier studies have shown that heat inactivation does not interfere with the immunogenicity of M. leprae. Immunogenicity was measured by foot-pad enlargement (FPE) after challenge with heat-killed M. leprae suspensions or by protection against infectious foot-pad challenge. The results indicated that the irradiation and 2-phase separation did not decrease immunogenicity but the NaOH treatment and enzyme digestion did.</p>  a0007-1021