CD4+ T-cell responses to foot-and-mouth disease virus in vaccinated cattle

• Published in: Journal of general virology 2013-01, Vol.94 (Pt 1), p.97-107
• Main Authors: Carr, B Veronica, Lefevre, Eric A, Windsor, Miriam A, Inghese, Cristina, Gubbins, Simon, Prentice, Helen, Juleff, Nicholas D, Charleston, Bryan
• Format: Article
• Language: English
• Subjects: Animal; Animals; Antibodies, Neutralizing - immunology; Antibodies, Viral - biosynthesis; Antibodies, Viral - immunology; Antigens, Viral - immunology; Cattle; Cattle Diseases - immunology; Cattle Diseases - prevention & control; Cattle Diseases - virology; CD4-Positive T-Lymphocytes - immunology; Foot-and-Mouth Disease - immunology; Foot-and-Mouth Disease - prevention & control; Foot-and-Mouth Disease - virology; Foot-and-mouth disease virus; Foot-and-Mouth Disease Virus - immunology; Interferon-gamma - immunology; Longitudinal Studies; Lymphocyte Activation - immunology; Vaccination - veterinary; Vaccines, Inactivated - immunology; Viral Vaccines - administration & dosage; Viral Vaccines - immunology
• ISSN: 0022-1317; 1465-2099; 1465-2099
• DOI: 10.1099/vir.0.045732-0

We have performed a series of studies to investigate the role of CD4(+) T-cells in the immune response to foot-and-mouth disease virus (FMDV) post-vaccination. Virus neutralizing antibody titres (VNT) in cattle vaccinated with killed FMD commercial vaccine were significantly reduced and class switching delayed as a consequence of rigorous in vivo CD4(+) T-cell depletion. Further studies were performed to examine whether the magnitude of T-cell proliferative responses correlated with the antibody responses. FMD vaccination was found to induce T-cell proliferative responses, with CD4(+) T-cells responding specifically to the FMDV antigen. In addition, gamma interferon (IFN-γ) was detected in the supernatant of FMDV antigen-stimulated PBMC and purified CD4(+) T-cells from vaccinated cattle. Similarly, intracellular IFN-γ could be detected specifically in purified CD4(+) T-cells after restimulation. It was not possible to correlate in vitro proliferative responses or IFN-γ production of PBMC with VNT, probably as a consequence of the induction of T-independent and T-dependent antibody responses and antigen non-specific T-cell responses. However, our studies demonstrate the importance of stimulating CD4(+) T-cell responses for the induction of optimum antibody responses to FMD-killed vaccines.