Th17 cells are implicated in a variety of inflammatory disorders including Spondyloarthritis (SpA). Ankylosing spondylitis (AS), the most common SpA, is genetically associated with HLA-B27 and IL-23R polymorphisms, although the link remains unexplained. In addition to classically folded heterotrimers, HLA-B27 can form β2m-free homodimers (B272). B272, as well as free heavy chains, are able to interact with KIR3DL2. I have shown an expansion of KIR3DL2+ CD4+ T cells in peripheral blood of AS patients and HLA-B27+ healthy controls. Although KIR3DL2+ CD4+ T cells comprise a minority of CD4+ T cells in peripheral blood, KIR3DL2+ CD4+ T cells account for the majority of peripheral blood CD4+ T cell IL-23R expression. KIR3DL2+ CD4+ T cells from synovial fluid are also enriched for IL-23R expression compared to matched peripheral blood samples. Moreover, treatment exposure to rIL-1/23 significantly increases IL-17 production by KIR3DL2+ CD4+ T cells in AS patients but not RA patients and healthy controls. KIR3DL2+ CD4+ T cells from AS patients produce more IL-17 than KIR3DL2+ CD4+ T cells from HLA-B27- healthy controls. KIR3DL2+ CD4+ T cells from AS patients and healthy controls are also enriched for dual production of IL-17 and IFNγ, consistent with the theory that AS is a Th17 or a Th17/1 driven disease. I have shown that naïve CD4+ T cells express KIR3DL2 de novo after activation. Interaction with B272-expressing cells acts to maintain and/or further increase KIR3DL2 expression. Interaction with B272-expressing cells also increases expression of Bcl-2. I propose that interaction of KIR3DL2+ CD4+ T cells with B272 preferentially promotes the survival of these pro-inflammatory cytokine-producing KIR3DL2+ CD4+ T cells in SpA. HD6, a B272-specific monoclonal antibody, decreases IL-17 production by PBMCs from AS patients, making it an attractive candidate therapeutic reagent in the treatment of AS and other HLA-B27-associated SpA.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:595928 |
| Date | January 2013 |
| Creators | Ridley, Anna Louise |
| Contributors | Paul, Bowness |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://ora.ox.ac.uk/objects/uuid:1f3f6651-68f8-4bfa-89ee-15bb6d279ed3 |
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