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ispartof: FRONTIERS IN IMMUNOLOGY vol:14 ispartof: location:Switzerland status: published

Background Literature indicates that children from ethnic minorities are at increased risk of sustaining burns. Moreover, parents may experience more psychological distress but why this is the case is poorly investigated. Methods A prospective study including 120 mothers and 106 fathers of preschool children, of which 23 mothers and 24 fathers had an ethnic minority background, investigated levels of parental feelings of guilt, depressive and posttraumatic stress symptoms and compared Dutch parents with parents from different ethnic backgrounds on these outcomes. A qualitative study with 46 parents, 24 Dutch and 22 from different ethnic minority backgrounds, explored how they coped with the consequences of the burns. Results Results revealed more symptoms of posttraumatic stress and depression in ethnic minority parents. Ethnic minority fathers also had more guilt feelings. Lower social support, medical communication hampered by language barriers, lower health literacy and passive communication styles, (aspects of) religious coping and barriers to psychosocial care may partly explain the differences. Conclusions Parents with an ethnic minority background are at risk to experience increased distress after their child’s burn injury. By exploring the aforementioned factors, health care professionals may increase the family’s wellbeing. It may provide a starting point to offer tailored help.

Basophils are circulating granulocytes, best known as effector cells in allergic reactions. Recent studies in mice suggest that they might also participate in the suppression of chronic inflammation. The aim of this study was to assess the ability of purified human basophils to modulate monocyte responses upon IL-33 and IgE triggering. Activation of human basophils with IL-33 induced the production of IL-4 and the release of histamine, and enhanced their IgE-mediated activation. In addition, basophils triggered with IL-33 and anti-IgE significantly suppressed the LPS-induced production of the proinflammatory cytokine TNF-alpha and the upregulation of the costimulatory molecule CD80 by monocytes. These effects were mainly explained by the release of histamine, as they could be inhibited by the histamine receptor 2 antagonist ranitidine, with a smaller contribution of IL-4. In contrast, basophil-derived IL-4 and histamine had opposing effects on the expression of the inhibitory Fc gamma receptor IIb and the production of IL-10 by monocytes. Our data show that basophils can influence monocyte activation and suggest a previously unrecognized role for human basophils in the modulation of monocyte-mediated immune responses, through the balanced secretion of histamine and IL-4.

High-grade osteosarcoma occurs predominantly in adolescents and young adults and has an overall survival rate of about 60%, despite chemotherapy and surgery. Therefore, novel treatment modalities are needed to prevent or treat recurrent disease. Natural killer (NK) cells are lymphocytes with cytotoxic activity toward virus-infected or malignant cells. We explored the feasibility of autologous and allogeneic NK cell–mediated therapies for chemotherapy-resistant and chemotherapy-sensitive high-grade osteosarcoma. The expression by osteosarcoma cells of ligands for activating NK cell receptors was studied in vitro and in vivo, and their contribution to NK cell–mediated cytolysis was studied by specific antibody blockade. Chromium release cytotoxicity assays revealed chemotherapy-sensitive and chemotherapy-resistant osteosarcoma cell lines and osteosarcoma primary cultures to be sensitive to NK cell–mediated cytolysis. Cytolytic activity was strongly enhanced by IL-15 activation and was dependent on DNAM-1 and NKG2D pathways. Autologous and allogeneic activated NK cells lysed osteosarcoma primary cultures equally well. Osteosarcoma patient–derived NK cells were functionally and phenotypically unimpaired. In conclusion, osteosarcoma cells, including chemoresistant variants, are highly susceptible to lysis by IL-15-induced NK cells from both allogeneic and autologous origin. Our data support the exploitation of NK cells or NK cell–activating agents in patients with high-grade osteosarcoma. Electronic supplementary material The online version of this article (doi:10.1007/s00262-010-0965-3) contains supplementary material, which is available to authorized users.

Objective Mast cells have been implicated in the pathogenesis of rheumatoid arthritis (RA). In particular, their activation by interleukin-33 (IL-33) has been linked to the development of arthritis in animal models. The aim of this study was to evaluate the functional responses of human mast cells to IL-33 in the context of RA. Methods Human mast cells were stimulated with IL-33 combined with plate-bound IgG or IgG anti-citrullinated protein antibodies (ACPAs), and their effects on monocyte activation were evaluated. Cellular interactions of mast cells in RA synovium were assessed by immunofluorescence analysis, and the expression of messenger RNA (mRNA) for mast cell-specific genes was evaluated in synovial biopsy tissue from patients with early RA who were naive to treatment with disease-modifying antirheumatic drugs. Results IL-33 induced the up-regulation of Fcγ receptor type IIa and enhanced the activation of mast cells by IgG, including IgG ACPAs, as indicated by the production of CXCL8/IL-8. Intriguingly, mast cell activation triggered with IL-33 and IgG led to the release of mediators such as histamine and IL-10, which inhibited monocyte activation. Synovial mast cells were found in contact with CD14+ monocyte/macrophages. Finally, mRNA levels of mast cell-specific genes were inversely associated with disease severity, and IL-33 mRNA levels showed an inverse correlation with the levels of proinflammatory markers. Conclusion When human mast cells are activated by IL-33, an immunomodulatory phenotype develops, with human mast cells gaining the ability to suppress monocyte activation via the release of IL-10 and histamine. These findings, together with the presence of synovial mast cell-monocyte interactions and the inverse association between the expression of mast cell genes at the synovial level and disease activity, suggest that these newly described mast cell-mediated inhibitory pathways might have a functional relevance in the pathogenesis of RA.

Rheumatoid arthritis (RA) is an autoimmune disease characterised by chronic inflammation of the joints. Anti-citrullinated protein antibodies (ACPA) are highly specific for RA and are associated with a more severe disease progression. ACPA have also been shown to have a pathological role in RA. In animal models of RA, ACPA enhances arthritis. Furthermore, in vitro generated immune complexes with ACPA can activate macrophages and the complement system in the human system. Recently, a direct functional and specific response of Fc epsilon RI+ immune cells towards citrullinated proteins was demonstrated. Basophils of ACPA+ RA patients are activated by citrullinated proteins that cross link the Fc epsilon RI receptor via IgE-ACPA, physiologically bound to the receptor. In addition, synovial mast cells from ACPA+ RA patients show a more activated phenotype than mast cells from ACPA-patients. These findings underline the suggestion that ACPA+ and ACPA-RA are two different disease entities and point to a possible functional role of ACPA and Fc epsilon RI+ cells in the pathogenesis of RA.