Laboratório de Protozoologia - Instituto de Medicina Tropical da Universidade de São Paulo, São Paulo, Brazil.
Departamento de Parasitologia, Instituto de Ciências Biomédica, Universidade de São Paulo, São Paulo, Brazil.
Biomed Pharmacother. 2018 Oct;106:599-604. doi: 10.1016/j.biopha.2018.06.155. Epub 2018 Jul 11.
Gamma radiation induces protein changes that enhance immunogenicity for venoms, used in antivenin production. Coccidian parasites exposed to gamma radiation elicit immune response with protection in mice and man, but without studies on the effect of gamma radiation in soluble acellular extracts or isolated proteins. Toxoplasmosis is a highly prevalent coccidian disease with only one vaccine for veterinary use but with remaining tissue cysts. Total parasite extracts or recombinant proteins used as immunogen induce usually low protection. Here, we study gamma radiation effect on T. gondii extracts proteins (STAG) and its induced immunity in experimental mice models. By SDS-PAGE, protein degradation is seen at high radiation doses, but at ideal dose (1500 Gy), there are preservation of the antigenicity and immunogenicity, detected by specific antibody recognition or production after mice immunization. Immunization with STAG irradiated at 1500 Gy induced significant protection in mice immunized and challenged with distinct T. gondii strains. In their blood, higher levels of specific CD19, CD3CD4 and CD3CD8 activated cells were found when compared to mice immunized with STAG. Irradiated T. gondii tachyzoites extracts induce immune response and protection in mice in addition, could be a feasible alternative for Toxoplasma vaccine.
伽马射线诱导蛋白质变化，增强毒液的免疫原性，用于抗蛇毒血清的生产。球虫寄生虫暴露于伽马射线会引发免疫反应，在小鼠和人类中提供保护，但没有研究伽马射线对可溶性无细胞提取物或分离蛋白的影响。弓形体病是一种高度流行的球虫病，只有一种兽用疫苗，但仍有组织包囊。全寄生虫提取物或重组蛋白作为免疫原通常诱导低保护。在这里，我们研究了伽马射线对弓形虫提取物蛋白（STAG）的影响及其在实验小鼠模型中的诱导免疫作用。通过 SDS-PAGE，可以看到在高辐射剂量下蛋白质降解，但在理想剂量（1500Gy）下，抗原性和免疫原性得以保留，这可以通过特异性抗体识别或小鼠免疫后的抗体产生来检测。用 1500Gy 辐照的 STAG 免疫可显著保护用不同弓形虫株免疫和攻毒的小鼠。与用 STAG 免疫的小鼠相比，在其血液中发现了更高水平的特异性 CD19、CD3CD4 和 CD3CD8 激活细胞。此外，辐照的弓形虫速殖子提取物可诱导小鼠产生免疫反应和保护，这可能是弓形虫疫苗的一种可行替代方法。
