Ferreira Josie Haydée L, Gentil Luciana Girotto, Dias Suzana Souza, Fedeli Carlos Eduardo C, Katz Simone, Barbiéri Clara Lúcia
Department of Microbiology, Immunology and Parasitology, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil.
Vaccine. 2008 Jan 30;26(5):677-85. doi: 10.1016/j.vaccine.2007.11.044. Epub 2007 Dec 5.
The gene Ldccys1 encoding a cysteine proteinase of 30 kDa from Leishmania (Leishmania) chagasi, as well as the recombinant cysteine proteinase rLdccys1, obtained by cloning and expression of the Ldccys1 gene in the pHIS vector, were used to evaluate their ability to induce immune protective responses in BALB/c mice against L. (L.) chagasi infection. Mice were immunized subcutaneously with rLdccys1 plus Bacille Calmette Guerin (BCG) or Propionibacterium acnes as adjuvants or intramuscularly with a plasmid carrying the Ldccys1 gene (Ldccys1/pcDNA3) and CpG ODN as the adjuvant, followed by a booster with rLdccys1 plus CpG ODN. Two weeks after immunization the animals were challenged with 1 x 10(7) amastigotes of L. (L.) chagasi. Both immunization protocols induced significant protection against L. (L.) chagasi infection as shown by a very low parasite load in the spleen of immunized mice compared to the non-immunized controls. However, DNA immunization was 10-fold more protective than immunization with the recombinant protein. Whereas rLdccys1 induced a significant secretion of IFN-gamma and nitric oxide (NO), animals immunized with the Ldccys1 gene increased the production of IgG2a antibodies, IFN-gamma and NO. These results indicated that protection triggered by the two immunization protocols was correlated to a predominant Th1 response.
编码来自恰加斯利什曼原虫（利什曼原虫属）的30 kDa半胱氨酸蛋白酶的基因Ldccys1，以及通过在pHIS载体中克隆和表达Ldccys1基因获得的重组半胱氨酸蛋白酶rLdccys1，被用于评估它们在BALB/c小鼠中诱导针对恰加斯利什曼原虫感染的免疫保护反应的能力。小鼠皮下注射rLdccys1加卡介苗（BCG）或痤疮丙酸杆菌作为佐剂，或肌肉注射携带Ldccys1基因的质粒（Ldccys1/pcDNA3）和CpG ODN作为佐剂，随后用rLdccys1加CpG ODN进行加强免疫。免疫两周后，用1×10⁷个恰加斯利什曼原虫的无鞭毛体攻击动物。与未免疫的对照相比，两种免疫方案均诱导了对恰加斯利什曼原虫感染的显著保护，表现为免疫小鼠脾脏中的寄生虫载量非常低。然而，DNA免疫的保护作用比重组蛋白免疫强10倍。虽然rLdccys1诱导了IFN-γ和一氧化氮（NO）的显著分泌，但用Ldccys1基因免疫的动物增加了IgG2a抗体、IFN-γ和NO的产生。这些结果表明，两种免疫方案引发的保护作用与主要的Th1反应相关。
