Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 13, 1998
Publication Date: N/A
Interpretive Summary: Worm parasites that infect the intestines of man and livestock have complex life cycles and migratory paths through the body of the host that they infect. There are many different immune responses that are stimulated by the parasite, but much of the response may not be important to eliminating the parasite. There is a need to measure specific immunity at the site of the infection in the intestine, but this is technically difficult. The current study was able to develop a technique that demonstrated specific and local immune responses in the intestinal immune tissues. The results indicate that the responses are very different from those that are induced in other sites in the body that are not involved in protective immunity. The usefulness of this technique will be in its ability to measure local immunity after vaccination. This will be of importance in determining the effectiveness of a potential vaccine against intestinal parasites that have few vaccines available. The importance of this study will be recognized by scientists in industries that are involved in the production of vaccines against infectious diseases, and to researchers that study these interactions.
An enzyme-linked immunospot (ELISPOT) assay was developed to measure total and parasite antigen-specific IgG and IgA antibody secreting cells (ASC) from gut-associated lymphoid tissues (GALT) of Trichuris suis- infected pigs. The local enteral antibody response were compared to parenteral responses in the spleen and submandibular lymph nodes, as well as serum antibody responses. The hypotheses to be tested was that parasite antigen-specific ASC would be greatest in lymphoid tissue draining the site of infection compared to parenteral lymphoid tissues, and that IgA ASC would predominate over IgG ASC in the lamina propria. The total IgG and IgA ASC frequencies from the spleen, SI-MLN, and IC-PP did not significantly change (P>0.05) during a primary infection, while there was a significant increase (P>0.05) in total IgG ASC in C-MLN. Antigen-specific IgG ASC had the highest frequency in C-MLN, whereas, antigen-specific IgA ASC predominated in the lamina propria of the proximal colon. The ELISPOT assay provides important information on the exquisite compartmentalization of the swine gastrointestinal immune response to T. suis. This technique should be useful for monitoring relevant GALT responses to vaccination.