Thesis (Ph.D.)--Aberdeen University, 2008. / Title from web page (viewed on June 15, 2009). Includes bibliographical references.

Experimental Autoimmune Uveitis (EAU) is the murine and rat model of the equivalent chronic inflammatory condition in humans. Tolerance to EAU can be induced via a single intra-nasal administration of the retinal autoantigen interphotoreceptor retinoid-binding protein (hIRBP_1-20). Tolerance initiation to EAU has been associated with an initial elevation of Th2-type cytokines in the cervical lymph nodes and spleens of experimental animals. Moreover, tolerance initiation was enhanced in mice with inhibited expression of the myeloid cell-regulatory protein CD200. Binding of CD300/CD200R initiates a signalling cascade that ultimately results in the down-regulation of myeloid cell activation. Therefore, enhanced tolerance initiation in the CD200-deficient mice was a paradox and the main aim of this study was to examine the molecular events leading to enhanced tolerance. The first aim of this study was the identification of the exact time-point of tolerance initiation. Because of the association of Th2-type cytokines in tolerance induction, Northern Blotting detection for the <i>Stat6</i> transcript was performed. Maximal expression of the <i>Stat6</i> transcript was observed in the spleens of the CD200-deficient mice 8 h post-tolerisation. Having identified 8 h as a potentially relevant point in tolerance initiation, a GenaArray study was performed for the analysis of global gene expression in the cervical lymph nodes of IRBP-tolerised animals in respect to the sham-terrorised controls. Furthermore, the alternative molecular pathways initiated or inhibited in the cervical lymph nodes and spleens of CD20-deficient animals in respect to the WT controls were also examined. The results obtained in the microarray study were verified by Western Blotting and qRT-PCR. The results obtained in our study demonstrated that the nasal administration of autoantigen and the shift from a WT to a CD200-deficient phenotype had more diverse biological effects than previously thought.