Accession Number : ADA568065


Title :   Advanced Development of Leishmania Topical Skin Test Antigen


Descriptive Note : Final rept. 18 Jun 2009-31 Aug 2012


Corporate Author : ALLERMED LABS INC SAN DIEGO CA


Personal Author(s) : Nielson, Jr, H S


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a568065.pdf


Report Date : 28 Sep 2012


Pagination or Media Count : 31


Abstract : The lysate of Leishmania tropica promastigotes is a complex mixture of substances, including proteins in the range of 8 kDa to 70 kDa. In Leishmania na ve adult humans, the lysate can cause sensitization manifest by the conversion of a negative to positive delayed-type hypersensitivity (DTH) skin test. This was observed on the third skin test with 30 ug and 50 ug doses of the crude lysate administered intradermally at monthly intervals. Fractionation of the lysate identified dominant proteins at 8 kDa, 20 kDa, and 56-58 kDa. Skin tests in L. tropica sensitized guinea pigs with each of these fractions revealed significant differences in the reactivity of the fractions. The 8 kDa fraction, which contained approximately 95% of the lysate mass, failed to elicit a positive DTH response. Conversely, the 20 kDa and 56-56 kDa fractions tested at 1.0 ug, 3.0 ug and 10.0 ug protein elicited strongly positive skin tests comparable in size and intensity to a 50 g dose of the crude promastigote lysate. In Leishmania na ve guinea pigs, the crude lysate and the 8 kDa, 20 kDa and 56-58 kDa fractions all exhibited sensitizing properties at the doses studied. Similar tests were not conducted in Leishmania na ve humans.


Descriptors :   *LEISHMANIA , *SKIN TESTS , ANTIGENS , CONVERSION , DOSAGE , FRACTIONATION , GUINEA PIGS , RESPONSE , SENSITIZING


Subject Categories : Medicine and Medical Research
      Microbiology


Distribution Statement : APPROVED FOR PUBLIC RELEASE