Immunologic Changes And Mechanism Of Local Mucosal In Chicks Infected With Eimeria Necatrix

In this study, indirect enzymelinket immunosorbent assay(IELISA) and immunohistochemistry staining were used to discover the changes of content of the immunoglobulins (Igs) in local humor -tear, trachea fluid, bile, intestinal fluid; the changes of both Igs antibody-producing cells and percentage of T cells in local immune tissues—cecal tonsils, gland of Harder of the chicks primary and secondary infected with Eimeria necatrix (E.necatrix) respectively in order to reveal local mucosal mechanism of protective immunity of chicks infected with E.necatrix and offer important theory for development coccidiosis vaccine. The results were as follows:The content of IgA, IgM, IgG in local humor of chicks was enhanced compared with controls postinfection (PI) in different degree; the numbers of IgA, IgG, IgM, producing cells and the percentage of T cells in local mucosal immune tissues of infected chicks were significantly increased compared with those of without infected chicks; The observations showed that immune function of humoral and cellular in local mucosal immune tissues of chicks primary infected with E.necatrix were enhanced.The content of IgA, IgM, IgG in local humor; the number of IgA, IgM, IgG antibody-producing cells and the percentage of T cells in local mucosal immune tissues of chicks secondary infected with E.necatrix were also some extent low compared with primary infected chicks in different degree. Thereafter, the data above begin to increase. The number increased significantly compared with controls and primary infection chicks 14 days post secondary challenge infection.The results indicated that immune function of chicks challenged with high doses sporulated oocysts was decreased transitory but the chicks were well protected because of cellular and humoral immune levels excited by primary infected. On the other hand, cellular and humoral immune levels in local nucosal tissue of chicks secondary infected with E.necatrix were increased significantly in later time which indicated that immune recall response was came into being.In brief, some extent level of cellular immunity and humoral immunity against E.necatrix was elicited after primary infection, thereby resisted definited dose of oocytes of E.necatrix reinfection.