Leukotriene B4 mediates γδ T lymphocyte migration in response to diverse stimuli

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141926/1/jlb0323.pd

Perceptions of "Research Integrity" among professionals working on research in a public Brazilian research institution (INTEGRITY).

This project aims to collect and present data on the perceptions of “Research Integrity” among professionals working on research in a important Brazilian public reseach institution, the Fundação Oswaldo Cruz (Fiocruz)

Avaliação de ensaios clínicos no Brasil: histórico e atualidades

Resumo Ensaios clínicos devem ser aprovados e acompanhados por autoridades éticas e regulatórias para garantir que a conduta ética e os aspectos técnicos das pesquisas estejam em conformidade com os padrões exigidos. O conhecimento desse processo é primordial para que estudos sejam delineados e conduzidos de acordo com os padrões aplicáveis, sendo parte essencial para a capacitação técnica e científica nacional. No Brasil, a avaliação dos estudos é realizada pelos comitês de ética em pesquisa, pela Comissão Nacional de Ética em Pesquisa e pela Agência Nacional de Vigilância Sanitária. Pesquisadores e patrocinadores alegam que o tempo para aprovação e início de ensaios clínicos limita novos estudos. No entanto, as normas brasileiras estão em contínuo aperfeiçoamento, o que demonstra interesse e capacidade em aprimorar os trâmites, sem perder a qualidade na avaliação ética

Mechanisms of T-Lymphocyte Accumulation during Experimental Pleural Infection Induced by Mycobacterium bovis BCG▿

Tuberculous pleurisy is a frequent extrapulmonary manifestation characterized by accumulation of fluid and inflammatory cells in the pleural space. Here, we investigated the mechanisms of T-lymphocyte accumulation in the pleural space by using a murine model of pleurisy induced by Mycobacterium bovis BCG. Intrathoracic (i.t.) injection of BCG (4.5 × 105 bacteria/cavity) induced accumulation of T lymphocytes in the pleural cavities of C57BL/6 mice. We observed the presence of CFU in pleural washes conducted 1, 2, 3, 7, and 15 days after pleurisy induction. Pretreatment with fucoidan inhibited T-lymphocyte accumulation at 1 day, but not at 15 days, after BCG-induced pleurisy. Accordingly, adoptive transfer of fluorescein isothiocyanate-labeled blood mononuclear cells to infected mice showed that T lymphocytes migrated into the pleural cavity 1 day (but not 15 days) after BCG injection. Cell-free pleural wash fluids recovered from mice 1 day after BCG i.t. stimulation (day 1 BCG-PW), but not day 7 or day 15 BCG-PW, induced in vitro T-cell transmigration, which was dependent on L-, P-, and E-selectins. In contrast, day 7 BCG-PW (but not day 1 BCG-PW) induced in vitro T-lymphocyte proliferation via interleukin-2 (IL-2) and gamma interferon (IFN-γ). Accordingly, in vivo IL-2 or IFN-γ neutralization abolished T-lymphocyte accumulation 7 days after pleurisy induction. Our results demonstrate that pleural infection induced by BCG leads to T-lymphocyte accumulation in two waves. The acute phase depends on selectin-mediated migration, while the second wave of T-lymphocyte accumulation seems to depend on a local proliferation induced by cytokines produced in situ

Role of Chemokine Receptor CCR4 and Regulatory T Cells in Wound Healing of Diabetic Mice

International audienceWound healing is a well-coordinated process that involves inflammatory mediators and cellular responses; however, if any disturbances are present during this process, tissue repair is impaired. Chronic wounds are one of the serious long-term complications associated with diabetes mellitus. The chemokine receptor CCR4 and its respective ligands, CCL17 and CCL22, are involved in regulatory T cell recruitment and activation in inflamed skin; however, the role of regulatory T cells in wounds is still not clear. Our aim was to investigate the role of CCR4 and regulatory T cells in cutaneous wound healing in diabetic mice. Alloxan-induced diabetic wild-type mice (diabetic) developed wounds that were difficult to heal, differently from CCR4 e/e diabetic mice (CCR4 e/e diabetic), and also from anti-CCL17/22 or anti-CD25einjected diabetic mice that presented with accelerated wound healing and fewer regulatory T cells in the wound bed. Consequently, CCR4 e/e diabetic mice also presented with alteration on T cells population in the wound and draining lymph nodes; on day 14, these mice also displayed an increase of collagen fiber deposition. Still, cytokine levels were decreased in the wounds of CCR4 e/e diabetic mice on day 2. Our data suggest that the receptor CCR4 and regulatory T cells negatively affect wound healing in diabetic mice