Immunosuppressive mechanism of chicken Marek's disease

One hundred healthy chicks were divided into uninfected control and infected group which was infected with MD virus at one-day old. At 5, 25 and 45 days postinfection, the chicks were taken to detect. the immunological changes. The results were found that the interlukine-2 inductive activity, IL-2 receptor expression, proliferative reaction and number of T cell markedly decreased in the thymus and spleen of infected chicks; the number of IgG, IgM, IgA antibody producing cells (APC) and its rough-surfaced endoplasmic recticulum and content of immunoglobulin apparently reducde in the Bursa Fabricius and spleen; the amount of T cell, IgG, IgM, IgA significantly dropped in the blood. These indicated that the immunoregulation of IL-2, cellular and humoral immunity marked suppressed in the immune organs of infected chicks.