Pérez-Jiménez Eva, Kochan Grazyna, Gherardi M Magdalena, Esteban Mariano
Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología, CSIC, Ciudad Universitaria de Cantoblanco, 28049, Madrid, Spain.
Microbes Infect. 2006 Mar;8(3):810-22. doi: 10.1016/j.micinf.2005.10.004. Epub 2006 Jan 13.
An optimal vaccine against leishmaniasis should elicit parasite specific CD4+ and cytotoxic CD8+ T cells. In this investigation, we described a prime/boost immunization approach based on DNA and on poxvirus vectors (Western Reserve, WR, and the highly attenuated modified vaccinia virus Ankara, MVA), both expressing the LACK antigen of Leishmania infantum, that triggers different levels of specific CD8+ T cell responses and protection (reduction in lesion size and parasitemia) against L. major infection in mice. A prime/boost vaccination with DNA-LACK/MVA-LACK elicits higher CD8+ T cell responses than a similar protocol with the replication competent VV-LACK. Both CD4+ and CD8+ T cells were induced by DNA-LACK/MVA-LACK immunization. The levels of IFN-gamma and TNF-alpha secreting CD8+ T cells were higher in splenocytes from DNA-LACK/MVA-LACK than in DNA-LACK/VV-LACK immunized animals. Moreover, protection against L. major was significantly higher in DNA-LACK/MVA-LACK than in DNA-LACK/VV-LACK immunized animals when boosted with the same virus dose, and correlated with high levels of IFN-gamma and TNF-alpha secreting CD8+ T cells. In DNA-LACK/MVA-LACK vaccinated animals, the extent of lesion size reduction ranged from 65 to 92% and this protection was maintained for at least 17 weeks after challenge with the parasite. These findings demonstrate that in heterologous prime/boost immunization approaches, the protocol DNA-LACK/MVA-LACK is superior to DNA-LACK/VV-LACK in triggering specific CD8+ T cell immune responses and in conferring protection against cutaneous leishmaniasis. Thus, MVA-LACK is a safe and efficient vector for vaccination against leishmaniasis.
一种针对利什曼病的最佳疫苗应能引发寄生虫特异性的CD4+和细胞毒性CD8+ T细胞。在本研究中,我们描述了一种基于DNA和痘病毒载体(西储株,WR,以及高度减毒的改良安卡拉痘苗病毒,MVA)的初免/加强免疫方法,这两种载体均表达婴儿利什曼原虫的LACK抗原,该方法能引发不同水平的特异性CD8+ T细胞反应,并对小鼠的硕大利什曼原虫感染产生保护作用(病变大小和寄生虫血症减少)。与使用具有复制能力的VV-LACK的类似方案相比,用DNA-LACK/MVA-LACK进行初免/加强免疫能引发更高的CD8+ T细胞反应。DNA-LACK/MVA-LACK免疫诱导了CD4+和CD8+ T细胞。DNA-LACK/MVA-LACK免疫动物的脾细胞中分泌IFN-γ和TNF-α的CD8+ T细胞水平高于DNA-LACK/VV-LACK免疫动物。此外,当用相同病毒剂量加强免疫时,DNA-LACK/MVA-LACK免疫动物对硕大利什曼原虫的保护作用明显高于DNA-LACK/VV-LACK免疫动物,且与分泌IFN-γ和TNF-α的高水平CD8+ T细胞相关。在DNA-LACK/MVA-LACK免疫的动物中,病变大小减少的程度在65%至92%之间,并且在用寄生虫攻击后,这种保护作用至少维持17周。这些发现表明,在异源初免/加强免疫方法中,DNA-LACK/MVA-LACK方案在引发特异性CD8+ T细胞免疫反应和赋予抗皮肤利什曼病保护作用方面优于DNA-LACK/VV-LACK。因此,MVA-LACK是一种用于利什曼病疫苗接种的安全有效的载体。