Jin Huali, Kang Youmin, Zheng Guoxing, Xie Qifa, Xiao Chong, Zhang Xinyu, Yu Yang, Zhu Kaichun, Zhao Gan, Zhang Fuchun, Chen Aoshuang, Wang Bin
State Key Laboratory for Agro-Biotechnology, College of Biological Science, China Agricultural University, Beijing.
Virology. 2005 Jun 20;337(1):183-91. doi: 10.1016/j.virol.2005.03.029.
Although immunization has been used for eliciting immune response, here we show that it can also induce immune suppression. When a DNA vaccine encoding a viral antigen such as the VP1 protein from the foot and mouth disease virus is administered together with its recombinant protein antigen or a viral preparation containing the same antigen, the immunized animals developed significantly reduced antigen-specific T cell-mediated responses and became impaired to subsequent rechallenge with the same antigen. The induction of immune suppression is mediated by suppressor T cells, as demonstrated by an adoptive transfer experiment and mixed lymphocyte reactions. The induction of immune suppression in immunized animals is also correlated with a shift of cytokine balance, as reflected by an elevated level of IL-10 and reduced level of IFN-gamma or IL-2. Hence, co-immunization with DNA- and protein-based vaccines may represent a novel means for inducing active suppression against untoward immunity.
