The formation of granulomas around parasite eggs is the major cause of pathology in schistosomiasis. In addition, eggs or egg antigen are thought to be involved in the Th1 to Th2 shift seen in this disease. The majority of lymphostimulatory egg antigens are glycosylated and we have identified one oligosaccharide on egg glycoproteins as Lacto-N fu copentaose III (LNFPIII). LNFPIII contains the biologically interesting Lewis trisaccharide. LNFPIII, but not its non-fucosylated homologue, stimulates B22+, CD4, CD8, spleen cells from infected mice to proliferate and produce significant levels of IL-10 and PGE2. Thus, specific oligosaccharide found on schistosome egg antigens can activate non T- cells to produce mediators known to down regulate Th1 populations. This is the first demonstration of a carbohydrate-dependent mechanism for cytokine elaboration. Fortuitously, identical and related sugars are found on lymphostimulatory egg antigens which we have purified. Thus, the proposed experiments will extend our observations on the roles specific carbohydrates play in CD4+ T cells subset regulation by measuring proliferation and IL-10 and PGE2 production from various murine and patient lymphocyte populations. We will then ask whether vaccination of mice with specific oligosaccharide alters CD4+ T cell subsets or granuloma formation/modulation in vivo. To further define the roles of B cells in Th1 -Th2 shifting and granuloma formation/modulation, we propose to examine responses to LNFPIII and granuloma formation/modulation in vivo and in vitro in transgenic """"""""B-less"""""""" mice in C57BI/6 mice, which do not respond to these sugars and have smaller granulomas. We will then compare the relative contributions that peptide versus define oligosaccharide play in these immune responses followed by structure mapping of the immunoreactive glycoforms.
The specific aims of this proposal are: 1) to further examine the lymphocytes respond to LNFPIII or other oligosaccharide, via the production of IL-10 and/or PGE2; 3) to test if immunization with LNFPIII or structurally related oligosaccharide influences CD4+T cell subset responses or alters granuloma formation/modulation in vivo; 4) to compare granuloma formation/modulation and immunoreactivity to define oligosaccharides in infected or immunized transgenic """"""""B-less"""""""" mice or mice of different genetic backgrounds; 5) to compare the roles oligosaccharide versus peptide moieties play in CD4+ T cells subset regulation and granuloma formation/modulation in vivo and in vitro; 6) To determine the structure of stimulatory glycoforms on purified, native egg antigens.
