REBECCA L O'BRIEN

..Our findings indicate that Vgamma1(+) gammadelta T cells reduce the ability of the innate immune system to destroy Listeria, even though other gammadelta T cells as a whole promote clearance of this pathogen...

..That certain mice lacking gammadelta T cells often spontaneously develop keratitis, characterized by a progressive and destructive inflammation of the cornea is reported here...

..The use of recombinant soluble versions of gammadeltaTCRs appears to be a promising approach to finding new ligands, and recent results using this method are reviewed...

..We conclude that both the development and the cytokine potential of the AHR-enhancing gammadelta T cells differs critically from that of Th2 cells and NKT cells, despite similar influences of these cell populations on AHR...

..These data are the first to demonstrate an important role for Th17-polarized CD4(+) T lymphocytes in the immune response directed against S. rectivirgula in this murine model of hypersensitivity pneumonitis and pulmonary fibrosis...

..These results demonstrate that TNF-alpha and activation of Vgamma1+ gammadelta T cells are required for the development of AHR after O3 exposure...

..Our findings suggest that CD8+ DCs in the lymphoid tissues enable an early step in the development of gammadelta T cells through direct cell contact. DC-expressed CD8 might take part in this interaction...

..Together, our data suggest that Ag itself, when acquired by γδ T cells, directs the specificity of their IgE suppression...

..Thus, airway allergen challenge differentially affects two distinct subsets of gammadelta T cells with nonoverlapping functional potentials, and the outcome is IgE suppression...

..To investigate additional factors in the spontaneous development of keratitis previously reported in B10.TCRδ⁻/⁻ female mice...

..However, after airway allergen exposure, suppressive gammadelta T cells become dominant. The underlying mechanisms are discussed...

..These findings establish Vgamma4(+) gammadelta T cells as negative regulators of AHR and show that their regulatory effect bypasses much of the allergic inflammatory response coincident with AHR...

..These findings indicate that chronic inhalation of B. subtilis can result in T cell accumulation in the lung and fibrosis, constituting a new model of immune-mediated pulmonary fibrosis...

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..Our results suggest that CD8(+) alphabeta T cells are the most potent inhibitors of gammadelta T cell homeostasis and exert their effect by competing for IL-15...

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..They also are revealed as a potentially useful target for immune intervention...

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..The data suggest that lymphocytic synergism, which is key to the Ag-specific adaptive immune response, is also intrinsic to T cell-dependent innate responses...

..Surprisingly, gammadelta T cells are responsible for much of the IL-17 produced in several disease models, particularly early on...

..Interestingly, some gammadelta T cells produce IL-17 in response to IL-23 alone, even in naïve animals, suggesting they are already differentiated and may develop differently than CD4(+) alphabeta Th17 cells...

..To settle the questions of whether peptides can be ligands for the γδ TCRs, and whether responses to small peptides might occur normally, peptide binding will have to be demonstrated, and natural peptide ligands identified...

..A decrease in total IgG and IgG2a anti-collagen Abs was also seen. These results suggest that Vgamma4/Vdelta4(+) gammadelta T cells exacerbate CIA through their production of IL-17...

..Here we outline this hypothetical mechanism and discuss its possible implications for thymic selection and potential for complementing known innate and adaptive mechanisms of immune defense...

..Here, we describe functionally distinct, TCR-defined gammadelta T cell subsets, and evidence that their functions are predetermined in the thymus...

..This new information underscores the significance of CD27 in γδ T-cell functional differentiation, and is likely to facilitate the development of γδ T-cell-based clinical immunotherapy...

..Taken together, our results highlight a novel CD4 T cell-dependent mechanism that shapes the generation of IL-17+ γδ T cells in naive settings...

..Thus, at present, much evidence suggests that gammadelta T cells function in an innate manner, although they are arguably the most complex and advanced cellular representatives of the innate immune system...

..While posing a unique challenge in the maintenance of self-tolerance, this broad reactivity pattern might enable multiple overlapping uses of γδ T-cell populations, and thus generate a more efficient immune response...

..We conclude that AHR-suppressive Vgamma4(+) gammadelta T cells require induction. They are induced by allergen stimulation, but AHR suppression by these cells does not require their restimulation with the same allergen...

..These findings show how gammadelta T cells can be both inhibitors and enhancers of AHR and airway inflammation, and they provide further support for the hypothesis that TCR expression and function cosegregate in gammadelta T cells...

..The continuous interaction of gammadelta T cells with these sentinels likely is related to their protective role...

..3 sTCR. The backup approach involves generation of ligand specific mAbs, identified by their ability to block sTCR/ligand binding, as reagents to affinity-purify the ligand. ..

..In addition, we will carryout experiments designed to examine whether the disease is autoimmune, results from bacterial infection, or stems from damage caused by a chemical released from dirty cage litter. ..

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..We will also examine the importance to disease outcome of the ability of each subset to produce particular cytokines, induce the death of other cells, and undergo apoptosis. ..