Submitted to: American Veterinary Medical Association Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 13, 2002
Publication Date: December 31, 2002
Citation: Gimeno, I.M., Witter, R.L., Hunt, H.D., Reed, W.M. 2002. Immunological features of serotype 1 marek's disease virus vaccines [abstract]. American Veterinary Medical Association. p. 19. Technical Abstract: In an attempt to evaluate immunological parameters that might be related with level of protection against Marek's disease, the immune responses induced by eight serotype 1 Marek's disease virus vaccines conferring different levels of protection have been characterized. A chronological study of several immunological parameters including natural killer activity, frequency of different lymphocyte subsets and expression of major histocompatibility complex (Mhc) class I and class II antigens was conducted. Compared to other vaccines, vaccines conferring the highest level of protection seemed to induce an earlier activation of the immune system (i.e. activation of T cells measured by the level of Mhc-II antigen expression, expansion of T cells CD4+ and greater natural killer cell activity). Pathogenic strains of serotype 1 MDV also induced early activation of the immune system. However, in contrast to vaccine strains, pathogenic viruses significantly reduced the level of both B cells and Mhc-II+ T cells by 7 days post inoculation due to a strong cytolytic infection of these cell types. Application of these findings in evaluating vaccine strains will be discussed.