title: Immunoprotective mechanisms in swine within the "grey zone" in antibody response after immunization with foot-and-mouth disease vaccine.
abstract: Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals caused by the FMD virus (FMDV). Vaccination represents one approach for limiting the effects of FMD. The level of protection in vaccinated animals after challenge with foot and mouth disease virus (FMDV) is closely related to the antibody titer, which can be classified into three zones: a "white zone", a "grey zone", and a "black zone". The aim of the present study was to clarify the immunoprotective mechanisms operating in the grey zone, in which vaccinated animals have intermediate antibody titers, making it difficult to predict the level of protection. Thirty-three pigs were used to analyze the distribution of lymphocyte subpopulations in whole blood and the expression levels of 40 cytokines before vaccination and challenge. The antibody titer in pigs in the grey zone ranged from 1:6-1:45. Cytotoxic T lymphocyte subpopulations, expression levels of Th1 cytokines such as tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin (IL)-12, IL-15, IL-18, and monocyte interferon gamma inducing factor (MIG), and of granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-1α, transforming growth factor-α (TGF-α), and TWEAK R varied between protected and unprotected animals. The results of this study suggest that the cellular immune response is the key factor responsible for immunoprotection in vaccinated animals with antibody titers within the grey zone.
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No.1, Xujiaping, Lanzhou, Gansu 730046, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No.1, Xujiaping, Lanzhou, Gansu 730046, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No.1, Xujiaping, Lanzhou, Gansu 730046, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Jin
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No.1, Xujiaping, Lanzhou, Gansu 730046, China. Electronic address: majunwu@caas.cn.
authors.forename: Junwu
authors.initials: J
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No.1, Xujiaping, Lanzhou, Gansu 730046, China.
authors.forename: Hu
authors.initials: H
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, National Foot and Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No.1, Xujiaping, Lanzhou, Gansu 730046, China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis* / Q000097:blood; D054370:Chemokine CXCL9 / Q000235:genetics / Q000276:immunology; D005536:Foot-and-Mouth Disease / Q000097:blood / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D029544:Foot-and-Mouth Disease Virus / Q000187:drug effects / Q000254:growth & development / Q000276:immunology; D015870:Gene Expression; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000276:immunology; D007111:Immunity, Cellular / Q000187:drug effects; D056724:Immunity, Humoral / Q000187:drug effects; D007114:Immunization; D007371:Interferon-gamma / Q000235:genetics / Q000276:immunology; D018664:Interleukin-12 / Q000235:genetics / Q000276:immunology; D019409:Interleukin-15 / Q000235:genetics / Q000276:immunology; D020382:Interleukin-18 / Q000235:genetics / Q000276:immunology; D053582:Interleukin-1alpha / Q000235:genetics / Q000276:immunology; D013552:Swine; D013553:Swine Diseases / Q000097:blood / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects* / Q000276:immunology / Q000821:virology; D000074050:TWEAK Receptor / Q000235:genetics / Q000276:immunology; D016211:Transforming Growth Factor alpha / Q000235:genetics / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage*
chemical_list: D000914:Antibodies, Viral; D054370:Chemokine CXCL9; D019409:Interleukin-15; D020382:Interleukin-18; D053582:Interleukin-1alpha; D000074050:TWEAK Receptor; D016211:Transforming Growth Factor alpha; D014409:Tumor Necrosis Factor-alpha; D014765:Viral Vaccines; D018664:Interleukin-12; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor
keywords: Challenge; Grey zone; Protection; Vaccination