Effects of Chronic Heat Stress on Immune Responses of the Foot-and-Mouth Disease DNA Vaccination
Department of Veterinary Pathology, College of Veterinary Medicine, China Agricultural University, Beijing, China. DNA and Cell Biology
(Impact Factor: 2.06).
09/2007; 26(8):619-26. DOI: 10.1089/dna.2007.0581
The main purpose of this study was to assess the effects of chronic heat stress (CHS) on humoral and cellular responses of DNA vaccination. Mice with the CHS were exposed to a temperature set at 38 +/- 1 degrees C, 2h per day, for 35 days, and mice with thermoneutral (TN) temperature were maintained at 24 +/- 1 degrees C for the same period of time. Both groups of mice were immunized with a DNA vaccine-expressed viruscapsid protein 1 (VP1) of foot-and-mouth disease virus (FMDV), and we tested their antigen-specific humoral and cellular responses during the treatments. Compared with the TN group, titers of total Imunoglobulin G (IgG) and IgG1 and expression of interleukin 4 (IL-4) in CD4(+) cells of CHS group were not affected significantly. In contrast, the levels of IgG2a, T cell proliferations, and expression of interferon-gama (IFN-gamma) in both CD4(+) and CD8(+) cells were suppressed significantly, and cytotoxic T-lymphocyte (CTL) responses in vivo were also weakened by the CHS condition. These results indicate that the CHS treatment has negatively affected the immune responses of DNA vaccination and particularly impaired to the cell-mediated responses. It suggests that vaccination in animals is affected by the changes of ambient temperature.
Available from: Qiang Zou
- "Chronic heat stress (CHS) occurs under the high temperature conditions which are not necessarily extreme but for a long time, for example, in the hot summer. Although prolonged exposure to these environments may not be lethal, it can alter the animal's growth performance, the immune competence , and disease resistance       . Our previous studies had demonstrated that CHS significantly inhibited both systemic and local innate immune responses, including reduced numbers of pulmonary alveolar macrophages (PAMs), delayed maturation of dendritic cells (DCs), and decreased levels of IL-6, IFN-í µí»½, and HSP70 mRNA . "
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ABSTRACT: Chronic heat stress (CHS) is known to have negative impacts on the immune responses in animals and increases their susceptibility to infections including the highly pathogenic avian influenza virus H5N1. However, the role of regulatory T cells (Tregs) in CHS immunosuppression remains largely undefined. In this study, we demonstrated a novel mechanism by which CHS suppressed both Th1 and Th2 immune responses and dramatically decreased the protective efficacy of the formalin-inactivated H5N1 vaccine against H5N1 influenza virus infection. This suppression was found to be associated with the induced generation of CD4(+)CD25(+)FoxP3(+) Tregs and the increased secretions of IL-10 and TGF- β in CD4(+) T cells. Adoptive transfer of the induced Tregs also suppressed the protective efficacy of formalin-inactivated H5N1 virus immunization. Collectively, this study identifies a novel mechanism of CHS immunosuppression mediated by regulating CD4(+)CD25(+)Foxp3(+) Tregs.
Available from: Aziz Aksoy
- "Elevated HSP70 in the serum of patients who had developed fever associated with vaccinations may have arisen from HSP70 production in the body caused by the fever. There are numerous studies demonstrating that HSP70 increased even with the slightest increase in temperature, the manner in which the body normally reacts to fever[15,17,19]. This argument is supported by the fact that HSP70 expressions rose in feverish patients, whereas the pre-and post-vaccination values in the patients who did not develop fever remained the same. "
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ABSTRACT: For analyzing the changes in immunoglobulins, HSP70, ghrelin levels in blood samples were collected from volunteers vaccinated against swine flu before the vaccinations and on days 3, and 15, and 1 and 2 months after the vaccination in the presence or absence of fever associated with the it. The study included 11 subjects having developed a fever, and 13 subjects not having a fever, and 20 control subjects. Immunoglobulins were measured by nephelometry, and HSP70 and ghrelins by appropriate ELISA tests. The level of ghrelin was reduced, while the level of HSP70 was significantly increased in subjects who developed fevers. When temperatures were normalized, both levels were found similar to the control group. These results indicate that the increase in serum immunoglobulins levels associated with vaccinations, along with, elevations in HSP70 and reduced ghrelin levels associated with fever, may be the important parameters in the clinical evaluation and follow-up of treatments with vaccines.
Available from: PubMed Central
- "It has been applied to a number of viral, bacterial and parasitic disease models as well as several tumour models. There are a number of advantages on nucleic acid vaccines over conventional vaccines, such as long-term protection, long shelf life  and the ability to induce a wider range of immune response types. "
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ABSTRACT: Foot-and-Mouth Disease (FMD), as a major global animal disease, affects millions of animals worldwide and remains the main sanitary barrier to the international and national trade of animals and animal products. Inactivated vaccination is the most effective measure for prevention of FMD at present, but fail to induce long-term protection and content new requires for production of FMD vaccines. As a number of Researchers hope to obtain satisfactory novel vaccines by new bio-technology, novel vaccines have been studied for more than thirty years. Here reviews the latest research progress of new vaccines, summarizes some importance and raises several suggestions for the future of FMD vaccine.
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