Immunological Changes of Chicks Immunized with Marek's disease Vaccines and Challenged with Virulent MD Vims

摘要

The experiment was conducted to inoculate one-day old chicks with Marck's disease (MD) trivalent and hcrpcsvirus of turkey (HVT) vaccines separately, and then to challenge them with virulent MD virus (vMDV) at the age of 15 days, and 5, 25, 45 and 75days after the challenge with vMDV, comparing with the control-challenged chicks without immunization, to detect the immunoprotetive efficacy and dynamic changes of the inductive activity of interleukin-2(IL-2), expression of IL-2 receptor and proliferativc function of T cells in thymus and spleen; the number of ANAE~+T, AP~+T cells and IgG, IgM, IgA antibody-producing cells in Bursa Fabricius, spleen, thymus, cecal tonsil and Harder gland; as the amount of T cells and IgG, IgM, IgA in peripheral bloodas well as the content of IgG, IgM and IgA in the tear, trachea washings, bile and intestinal fluids of the experimental chicks. The experimental results firstly demonstrate that the immunoregulation of IL-2, and IL—2 receptor, the cellualr and humoralimmune responses were significantly enhanced in the central and peripheral immune organs; the local rnucosal immune function were markedly amplified in the respiratory and digestive tracts of the immunized—challenged. chicks, which were closely correlated with the immunoprotection against MD; the immune response and immunoprotcctivc effect of the trivalent vaccine—immunized chicks were much better than those of HVT vaccine-immunized chicks.