Submitted to: Pig Veterinary Society International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: September 15, 1998
Publication Date: N/A
Interpretive Summary: Neonatal pigs are usually unable to mount an effective intrinsic immune response. In early life, immune protection of piglets is mostly dependent on passively acquired maternal components. Later, after weaning, they develop their own immunity due to exposure to environmental antigens that produce changes in the immune cell population and related cytokine production. This deficit in the neonatal immune system predisposes piglets to infectious diseases. It is thus critical to identify the nature of this functional deficit to be able to apply prophylactic measures. The objective of this work was to analyze and compare the phenotype of the lymphocytes isolated from the blood, lymph node and mucosa associated tissues such as Peyer Patches, Intra epithelial and Lamina propria compartments. Preliminary results indicate that age had an effect on the phenotypic characteristics of the different lymphocyte subsets studied. Different populations of cells were identified at intestinal sites. This information is of special interest in understanding the pig's response to infectious pathogens. The information generated can be directly applied to develop new approaches to enhance the adaptive immune response of pigs. It should have a direct impact on improving the piglet's response to vaccines and or infectious diseases, thus resulting in improved health and productivity.
Technical Abstract: The neonatal pig exhibits an increased susceptibility to infectious diseases mainly due to its immature cellular immune system as compared to the adult pig. The objective of this study was to standardize techniques for the isolation and phenotypic identification of lymphocytes isolated from mucosa associated tissues as well as the periphery. Once established these techniques were used to assess the effect of piglet age on the development of the mucosal immune system. Two different populations of cells were characterized at intestinal level. Cell subset analyses using flow cytometric data suggested that the number and maturation state of neonatal lymphocytes changed as the piglets get older. After weaning, certain subsets became activated. Thus because lymphocyte subsets changed with age, we predicted that their functionality would vary. By using this model we can now identify the effect of function of immune cell subsets on pig health. We can also explore some of the properties of the cells that are involved in establishing an immune response at the mucosal level. Taken together, this set of data will be useful for the scientific community that is interested in studying the pathogenesis of enteric diseases, such as parasitemias and viral diseases. These studies should lead to identifying procedures that enhance the piglet's innate and adaptive immune response and thus have an impact on improving the pig response to infectious diseases or vaccinations.