Understanding Earth 7th Edition 28.pdf
Category:Climate and weather events
Category:Geology
Category:Geological processesOur long term objectives are to understand the function of the mucosal immune system, its role in the pathogenesis of mucosal infections, and how this system can be manipulated to prevent disease. We have characterized the existence of a Thl-like subset of CD4 cells that is localized to the lamina propria and exhibits specific properties of in vivo Thl cells. This Thl subset was characterized by its high IL-4 and low IFN-g production when stimulated with the enteric pathogen, Salmonella enterica serovar Typhimurium (S. T. Ty), and by its anergic state in an in vitro culture system. Interestingly, this Thl subset is not found in other mucosal sites such as the vaginal or salivary glands, nor is it found in the spleen. The presence of the mucosal Thl cells has led to a series of hypotheses regarding how this cell type functions in mucosal immunity. These hypotheses include 1) the possibility that the Thl cells play a role in maintaining mucosal tolerance and preventing immunopathogenesis, 2) the possibility that these Thl cells may be important in the early defense against mucosal pathogens and are associated with memory cells and responses, and 3) the possibility that the Thl cells may be important in suppressing the antigen-specific responses of other Th cell subsets or the responses of B cells or T cells to other mucosal antigens. The objective of this proposal is to test these hypotheses using novel techniques we have developed to elucidate the in vivo characteristics of these Thl cells and to test their function in adoptive transfer systems. We will examine the hypothesis that the Thl cells help to prevent mucosal immunopathology by producing IL-10 and that these cells are associated with mucosal memory. We will also examine the hypothesis that the Thl cells play a role in maintaining mucosal tolerance by protecting against tolerance induction to oral antigens. We will further explore how the Thl cells affect the immune response to a mucosal antigen. The model system will be the chicken in which our preliminary studies have shown that this Thl subset is activated in vivo and exists in large numbers in the gut. Our Specific Aims are: 1) to determine the expression of IL-10 by Thl cells in the intestinal tract, 2) to determine the induction of Thl cells by immunization, and 3) to determine the effect of oral
ac619d1d87

Related