DNA immunization with eukaryotic initiation factor-2 a of Toxoplasma gondi induces protective immuni

• 作 者: 陈佳 黄思扬 周东辉 李中原 Eskild Petersen 宋慧群 朱兴全
• 机 构: 中国农业科学院兰州兽医研究所家畜疫病病原生物学国家重点实验室甘肃省动物寄生虫病重点实验室,兰州730046
• 出 处: 中国畜牧兽医学会家畜寄生虫学分会第七次代表大会暨第十二次学术研讨会
• 发表日期: 2013年7期

　　Toxoplasma gondii infection is a serious health problem of economic importance to humans and animals worldwide.T.gondii eukaryotic initiation factor:2 a (TgIF2 a) plays a crucial role in parasite viability and is an important virulence factor ofT.gondii.To evaluate the vaccine potential of TgIF2 α,we constructed a novel eukaryotic plasmid pVAX:IF2 α expressing TgIF2 α from the RH strain and validated expression and immunogenicity in vitro in the Marc 145 cells expression system by indirect immunofluorescence (IFA).Administration ofpVAX:IF2 α intramuscularly induced specific humoral immune responses including high levels of specific TgIF2 α IgG antibody and a mixed IgG1/IgG2a response with predominance of IgG2aproduction.The cellular immune response was elicited,showing significant production ofIFN: γ and IL:2 associated with Th 1 type response,and thus strong cell:mediated cytotoxic activity with increased frequencies of IFN: γ parameters analyzed in both CD4+ and CD8+T cell compartments (CD4+ IFN: γ + T cells and CD8+ IFN: γ + T cells).Immunization resulted in partial protection against acute and chronic toxoplamosis in Kunming mice,demonstrated by a significantly prolonged survival time (15.9 ± 4.6 days) after challenge with the virulent RH strain and significant reduction in brain cyst (44.1%) against chronic infection with PRU cyst in contrast to control mice.Our data suggested that pVAX:IF2 α could be used as a DNA vaccine candidate against both acute and chronic T.gondii infection by the activation ofeffective humoral and cellular immune responses.