title: Induction of active immune suppression by co-immunization with DNA- and protein-based vaccines.
abstract: 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.
authors.affiliation: State Key Laboratory for Agro-Biotechnology, College of Biological Science, China Agricultural University, Beijing.
authors.forename: Huali
authors.initials: H
authors.lastname: Jin
authors.forename: Youmin
authors.initials: Y
authors.lastname: Kang
authors.forename: Guoxing
authors.initials: G
authors.lastname: Zheng
authors.forename: Qifa
authors.initials: Q
authors.lastname: Xie
authors.forename: Chong
authors.initials: C
authors.lastname: Xiao
authors.forename: Xinyu
authors.initials: X
authors.lastname: Zhang
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.forename: Kaichun
authors.initials: K
authors.lastname: Zhu
authors.forename: Gan
authors.initials: G
authors.lastname: Zhao
authors.forename: Fuchun
authors.initials: F
authors.lastname: Zhang
authors.forename: Aoshuang
authors.initials: A
authors.lastname: Chen
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
mesh_terms: D000818:Animals; D007111:Immunity, Cellular; D007114:Immunization; D007165:Immunosuppression Therapy; D007371:Interferon-gamma / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D019444:Vaccines, DNA / Q000008:administration & dosage* / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage* / Q000276:immunology
chemical_list: D011993:Recombinant Fusion Proteins; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic; D007371:Interferon-gamma