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dc.contributor.advisorMonestier, Marc
dc.creatorJha, Vibha
dc.date.accessioned2020-10-26T19:19:38Z
dc.date.available2020-10-26T19:19:38Z
dc.date.issued2009
dc.identifier.other864884690
dc.identifier.urihttp://hdl.handle.net/20.500.12613/1536
dc.description.abstractEtiological agents causing autoimmune diseases largely remain unknown. However, several lines of evidence suggest that environmental factors such as heavy metals (arsenic, lead and mercury) play a crucial role in the development of autoimmune disorders. In our model of mercury-induced autoimmunity, administration of subtoxic doses of HgCl2 to genetically susceptible strains of mice result in an autoimmune disease characterized by the production of highly specific anti-nucleolar autoantibodies, hypergammaglobulinemia and nephritis. However, mice can be tolerized to the disease by a single low dose administration of HgCl2 (tolerogenic dose). Previous studies from our lab had demonstrated that CD4+ CD25+ Foxp3+ regulatory T cells (Tregs) control the induction and maintenance of tolerance to mercury. We investigated the therapeutic role of Tregs in our model by utilizing agents that are known to stimulate in vivo expansion of Tregs. We studied two such agents, CD3-specific non-Fc receptor-binding [(Fab’)2 fragment] monoclonal antibody (Anti-CD3) and immune complexes containing recombinant IL-2 and anti-IL-2 monoclonal antibody (IC). In our model, treatment of mice with Anti-CD3 had no effect on Treg population. Administration of Anti-CD3 with the tolerogenic dose prevented induction of tolerance and failed to improve the maintenance period of tolerance. Anti-CD3 in presence of mercury activated the immune-system causing splenomegaly and expansion of B cell population. Overall, in contrast to its protective role in other experimental autoimmune disease models, Anti-CD3 exacerbated mercury-induced autoimmune syndrome. Treatment of mice with IC resulted in selective expansion of Tregs with a modest decrease in IgE levels and autoantibody production. Administration of IC with the tolerogenic dose led to a reduction in autoantibody response, thus IC was able to extend the maintenance period of tolerance to mercury. Lymphocyte Activation Gene-3 (LAG-3) is an inhibitory molecule that maintains lymphocyte homeostatic balance by controlling effector T cell expansion and contributing to the suppressive functions of Tregs. Thus, with the goal to understand the impact of homeostatic balance on Hg-induced autoimmunity, we investigated the role of LAG-3 in our model. Administration of an anti-LAG-3 monoclonal antibody broke tolerance to Hg resulting in autoantibody production and an increase in levels of serum IgE. Additionally, LAG-3-deficient B6.SJL mice exhibited an increased susceptibility to mercury-induced autoimmunity whereas, wild type controls suffered only from a mild disease. Moreover, adoptive transfer of wild-type CD4+ T cells protected LAG-3-deficient mice from mercury-induced autoimmunity. Therefore, we conclude that LAG-3 exerts an important regulatory effect on autoimmunity elicited by a common environmental pollutant.
dc.format.extent140 pages
dc.language.isoeng
dc.publisherTemple University. Libraries
dc.relation.ispartofTheses and Dissertations
dc.rightsIN COPYRIGHT- This Rights Statement can be used for an Item that is in copyright. Using this statement implies that the organization making this Item available has determined that the Item is in copyright and either is the rights-holder, has obtained permission from the rights-holder(s) to make their Work(s) available, or makes the Item available under an exception or limitation to copyright (including Fair Use) that entitles it to make the Item available.
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/
dc.subjectHealth Sciences, Immunology
dc.subjectAnti-cd3
dc.subjectAutoimmunity
dc.subjectLag-3
dc.subjectMercury
dc.subjectMurine
dc.subjectRegulatory T Cells
dc.titleCellular regulation of mercury-induced autoimmunity
dc.typeText
dc.type.genreThesis/Dissertation
dc.contributor.committeememberTsygankov, Alexander Y.
dc.contributor.committeememberButtaro, Bettina A.
dc.contributor.committeememberCohen, Philip L.
dc.contributor.committeememberDenny, Michael F.
dc.description.departmentMicrobiology and Immunology
dc.relation.doihttp://dx.doi.org/10.34944/dspace/1518
dc.ada.noteFor Americans with Disabilities Act (ADA) accommodation, including help with reading this content, please contact scholarshare@temple.edu
dc.description.degreePh.D.
refterms.dateFOA2020-10-26T19:19:38Z


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