Submitted to: Ostertagia Workshop
Publication Type: Proceedings
Publication Acceptance Date: 3/10/1996
Publication Date: N/A
Technical Abstract: The preeminence of Ostertagia ostertagi (Oo) in causing parasitic gastroenteritis is due in large part to the relative weak and delayed immune responses arising after initial contact with the parasite. The mucosal immune system represents the first line of immunological defense against Ostertagia ostertagi, but data on gastric lymphoid cells are limited. An isolation method to obtain viable intraepithelial (IEL) and lamina propria lymphocytes (LPL) from the abomasum was developed. Surface phenotype of LPL, IEL and abomasal lymph node cells (ABLN) in control animals and phenotype of LPL and ABLN in animals suffering a primary infection with Oo was assessed by indirect immunofluorescence staining. Within 3 weeks of infection number of lymphocytes recovered from the gastric lamina propria was highly elevated. Increased levels of immunoglobulin-bearing cells, gamma-delta T cells and activated T cells in both LP and ABLN were found in the infected animals. All the data indicated that a critical period in the protective immune response against Oo occurred during the first days of infections.