In the present study, we show that the intra-thoracic injection of ovalbumin (OVA, 12.5 microg per cavity) into C57BL/10 mice induced a significant increase in gammadelta T lymphocyte numbers in the pleural cavity, blood and thoracic lymph node of challenged mice. Such increase was significant within 12 h, peaked within 48 h and returned to basal counts within 120 h. Levels of CC chemokine ligand (CCL)-2/monocyte chemotactic protein-1, CCL5/regulated upon activation, normal T cell expressed and secreted, CCL3/macrophage inflammatory protein-1 alpha and CCL25/thymus-expressed chemokine were above control values in pleural washes recovered 24 h after OVA challenge (OPW) and were likely produced by pleural macrophages and mesothelial cells. Antigenic challenge also induced an up-regulation in CC chemokine receptor (CCR)-2, CCR5 and CCR9 on gammadelta T cells from pleural cavities, blood and lymph nodes, suggesting that cells found in mice pleural cavity migrate from secondary lymphoid organs into the inflammatory site via blood stream. The in vitro neutralization of CCL2 (but not of CCL3, CCL5 or CCL25) abrogated OPW-induced gammadelta T lymphocyte transmigration. Confirming such results, the in vivo administration of alpha-CCL2 mAb inhibited gammadelta T lymphocyte accumulation in the pleural cavity of challenged mice, whereas the blockade of CCL3, CCL5 or CCL25 showed no effect on gammadelta T cell mobilization. In addition, OVA challenge failed to induce gammadelta T lymphocyte accumulation in the pleural cavity of C57BL/6 CCR2 knockout mice, which also showed decreased numbers of these cells in blood and lymph nodes when compared with wild-type mice. Overall, such results demonstrate that CCR2/CCL2 pathway is crucial for gammadelta T lymphocyte mobilization during the allergic response.

Despite considerable efforts over the last decades, our understanding of leprosy pathogenesis remains limited. The complex interplay between pathogens and hosts has profound effects on host metabolism. To explore the metabolic perturbations associated with leprosy, we analyzed the serum metabolome of leprosy patients. Samples collected from lepromatous and tuberculoid patients before and immediately after the conclusion of multidrug therapy (MDT) were subjected to high-throughput metabolic profiling. Our results show marked metabolic alterations during leprosy that subside at the conclusion of MDT. Pathways showing the highest modulation were related to polyunsaturated fatty acid (PUFA) metabolism, with emphasis on anti-inflammatory, pro-resolving omega-3 fatty acids. These results were confirmed by eicosanoid measurements through enzyme-linked immunoassays. Corroborating the repertoire of metabolites altered in sera, metabonomic analysis of skin specimens revealed alterations in the levels of lipids derived from lipase activity, including PUFAs, suggesting a high lipid turnover in highly-infected lesions. Our data suggest that omega-6 and omega-3, PUFA-derived, pro-resolving lipid mediators contribute to reduced tissue damage irrespectively of pathogen burden during leprosy disease. Our results demonstrate the utility of a comprehensive metabonomic approach for identifying potential contributors to disease pathology that may facilitate the development of more targeted treatments for leprosy and other inflammatory diseases.

Herein, we provide evidence that during allergic inflammation, CCL25 induces the selective migration of IL-17 + γδ T cells mediated by α 4 β 7 integrin. Intrapleural injection of CCL25 into ovalbumin (OVA)-immunized C57BL/6 mice triggered the accumulation of γδ T lymphocytes expressing CCR9 (CCL25 receptor) and α 4 β 7 integrin in the pleura, but failed to attract αβ T lymphocytes. CCL25 attracted CCR6 + γδ T cells producing IL-17 (but not IFN-γ or IL-4). OVA challenge triggered increased production of CCL25 followed by the accumulation of CCR9 + , α 4 β 7 + , and CCR6 + /IL-17 + γδ T cells into the pleural cavities of OVA-immunized mice, which was inhibited by the in vivo neutralization of CCL25. The in vivo blockade of α 4 β 7 integrin also inhibited the migration of IL-17 + γδ T lymphocytes (but not of αβ T lymphocytes) into mouse pleura after OVA challenge, suggesting that the CCL25/α 4 β 7 integrin pathway is selective for γδ T cells. In addition, α 4 β 7 integrin blockade impaired the in vitro transmigration of γδ T cells across endothelium (which expresses α 4 β 7 ligands VCAM-1 and MadCAM-1), which was induced by CCL25 and by cell-free pleural washes recovered from OVA-challenged mice. Our results reveal that during an allergic reaction, CCL25 drives IL-17 + γδ T-cell mobilization to inflamed tissue via α 4 β 7 integrin and modulates IL-17 levels. Keywords: Adhesion molecules IntroductionLymphocytes bearing the γδ T-cell receptor (TCR) comprise a minor T-lymphocyte subset in blood and secondary lymphoid tissues and are preferentially localized in epithelial and mucosal tissues [1,2]. This unique subset of lymphocytes can provide rapid tissue-specific immune responses, without the requirement of antiCorrespondence: Dr. Carmen Penido e-mail: cpenido@far.fiocruz.br gen presentation or clonal expansion, and is able to produce a large repertory of Th1-, Th2-, and Th17-associated cytokines [2][3][4][5][6]. These characteristics make γδ T cells a crucial first line of defense during infection, tissue damage, or stress.γδ T cells have been shown to migrate into the airways during allergic inflammation highly controlled by a chemotactic gradient of chemokines produced in tissue [5,[7][8][9][10][11]. We have previously demonstrated that allergen-induced γδ T-cell accumulation is * These authors contributed equally to this work.www.eji-journal.eu Eur. J. Immunol. 2012. 42: 1250-1260 Immunomodulation 1251 paralleled with a marked production of chemokines in the tissue, including CCL25/TECK [11]. CCL25 is mostly described as a homeostatic chemokine that plays a major role in T-cell development in the thymus and in intraepithelial lymphocytes (IELs) homing into small intestine mucosa [12]. Recent data have provided evidence that CCL25 production increases during inflammatory processes that take place at nonmucosal tissues, such as autoimmune arthritis, atherosclerosis, and allergy [11,13,14]. Moreover, we and others have shown that γδ T lymphocytes migrate in vitro toward CCL25, via its counterpart receptor CCR9 [11,...

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Methyl gallate (MG) is a prevalent phenolic acid in the plant kingdom, and its presence in herbal medicines might be related to its remarkable biological effects, such as its antioxidant, antitumor, and antimicrobial activities. Although some indirect evidence suggests anti-inflammatory activity for MG, there are no studies demonstrating this effect in animal models. Herein, we demonstrated that MG (0.7-70 mg/kg) inhibited zymosan-induced experimental arthritis in a dose-dependent manner. The oral administration of MG (7 mg/kg) attenuates arthritis induced by zymosan, affecting edema formation, leukocyte migration, and the production of inflammatory mediators (IL-1β, IL-6, TNF-α, CXCL-1, LTB4, and PGE2). Pretreatment with MG inhibited in vitro neutrophil chemotaxis elicited by CXCL-1, as well as the adhesion of these cells to TNF-α-primed endothelial cells. MG also impaired zymosan-stimulated macrophages by inhibiting IL-6 and NO production, COX-2 and iNOS expression, and intracellular calcium mobilization. Thus, MG is likely to present an anti-inflammatory effect by targeting multiple cellular events such as the production of various inflammatory mediators, as well as leukocyte activation and migration.