Consumo de matéria seca, matéria orgânica, proteína bruta e extratoetério em ovinos recebendo feno de Tifton-85 e níveis crescentes de castanha de cajú.

Com o objetivo de avaliar o valor nutritivo da castanha de caju (Anacardium ocidentale) foi determinado o consumo da matéria seca (CMS), matéria orgânica (CMO), proteína bruta (CPB) e extrato etéreo (CEE) em borregos deslanados alojados em gaiolas metabólicas providas de separadores de fezes e urina recebendo feno de tifton-85 e níveis crescentes de castanha de caju nos níveis de zero, 10, 15, 20 e 25% castanha de caju com base na matéria natural, em um esquema inteiramente ao acaso com cinco tratamentos (nível de castanha de caju) e seis repetições (borregos) por tratamento perfazendo um total de 30 observações, empregando o método SNK a 5% de probabilidade para comparação das médias. Houve efeito do nível de inclusão de castanha de caju sobre o CMS, CMO, CPB e CEE, sendo que no caso do CMS e CMO houve depressão do consumo na dieta com 25% de castanha, no caso do CPB e CEE houve elevação no consumo sendo os maiores valores a partir de 20% de inclusão.Concluiu-se que o nível máximo de farelo de coco para ovinos seria de 19% de inclusão

Valor nutritivo do farelo de coco em ovinos: digestibilidade aparente da matéria seca, matéria orgânica, proteína bruta e extrato etéreo.

Com o objetivo de avaliar o valor nutritivo do farelo de coco (Cocus nucifera) foi determinado o coeficiente de digestibilidade aparente da matéria seca (DMS), matéria orgânica (DMO), proteína bruta (DPB) e extrato etéreo (DEE) em borregos deslanados alojados em gaiolas metabólicas providas de separadores de fezes e urina recebendo feno de tifton-85 e níveis crescentes de farelo de coco nos níveis de zero, oito, 17 e 25% de farelo de coco com base na matéria natural, em um esquema inteiramente ao acaso com quatro tratamentos (nível de farelo de coco) e seis repetições (borregos) por tratamento perfazendo um total de 24 observações, empregando o método SNK a 5% de probabilidade para comparação das médias. Não houve efeito do nível de inclusão do farelo de coco sobre o coeficiente de digestibilidade da MS, MO e PB, no entanto houve efeito sobre o coeficiente de digestibilidade do EE com a inclusão do farelo de coco. As regressões detectaram efeito quadrático do nível de farelo de coco sobre a DEE, sendo que com 19,20% de inclusão de farelo de coco, pela derivação da equação, haveria o maior coeficiente de digestibilidade do extrato etéreo. Concluiu-se que o nível de inclusão de farelo de coco até não influenciou os coeficientes de digestibilidade da matéria seca, matéria orgânica e proteína bruta, elevando da DEE, sedo que recomenda-se a inclusão máxima de 19,20% de farelo de coco em dietas para borregos visando maximização da digestibilidade do extrato etéreo

Inhibitory Receptors Are Expressed by Trypanosoma cruzi-Specific Effector T Cells and in Hearts of Subjects with Chronic Chagas Disease

We had formerly demonstrated that subjects chronically infected with Trypanosoma cruzi show impaired T cell responses closely linked with a process of T cell exhaustion. Recently, the expression of several inhibitory receptors has been associated with T cell dysfunction and exhaustion. In this study, we have examined the expression of the cytotoxic T lymphocyte antigen 4 (CTLA-4) and the leukocyte immunoglobulin like receptor 1 (LIR-1) by peripheral T. cruzi antigen-responsive IFN-gamma (IFN-γ)-producing and total T cells from chronically T. cruzi-infected subjects with different clinical forms of the disease. CTAL-4 expression was also evaluated in heart tissue sections from subjects with severe myocarditis. The majority of IFN-γ-producing CD4+ T cells responsive to a parasite lysate preparation were found to express CTLA-4 but considerably lower frequencies express LIR-1, irrespective of the clinical status of the donor. Conversely, few IFN-γ-producing T cells responsive to tetanus and diphtheria toxoids expressed CTLA-4 and LIR-1. Polyclonal stimulation with anti-CD3 antibodies induced higher frequencies of CD4+CTAL-4+ T cells in patients with severe heart disease than in asymptomatic subjects. Ligation of CTLA-4 and LIR-1 with their agonistic antibodies, in vitro, reduces IFN-γ production. Conversely, CTLA-4 blockade did not improved IFN-γ production in response to T. cruzi antigens. Subjects with chronic T. cruzi infection had increased numbers of CD4+LIR-1+ among total peripheral blood mononuclear cells, relative to uninfected individuals and these numbers decreased after treatment with benznidazole. CTLA-4 was also expressed by CD3+ T lymphocytes infiltrating heart tissues from chronically infected subjects with severe myocarditis. These findings support the conclusion that persistent infection with T. cruzi leads to the upregulation of inhibitory receptors which could alter parasite specific T cell responses in the chronic phase of Chagas disease

Expression of the innate immune receptor LILRB5 on monocytes is associated with mycobacteria exposure.

Antigen presenting cells (APC) are critical components of innate immunity and consequently shape the adaptive response. Leukocyte Ig Like Receptors (LILR) are innate immune receptors predominantly expressed on myeloid cells. LILR can influence the antigen presenting phenotype of monocytic cells to determine the nature of T cell responses in infections including Mycobaterium leprae. We therefore investigated the relevance of LILR in the context of Mycobacterium tuberculosis. Real-time PCR studies indicated that the transcriptional profile of the orphan receptor LILRB5 was significantly up-regulated following exposure to mycobacteria. Furthermore, LILRA1 and LILRB5 were able to trigger signalling through direct engagement of mycobacteria using tranfectant cells incorporating a reporter system. We describe for the first time the expression of this receptor on T cells, and highlight the potential relevance to mycobacterial recognition. Furthermore, we demonstrate that crosslinking of this receptor on T cells increases proliferation of cytotoxic, but not helper, T cells

CD85/LIR-1/ILT2 and CD152 (Cytotoxic T Lymphocyte Antigen 4) Inhibitory Molecules Down-Regulate the Cytolytic Activity of Human CD4(+) T-Cell Clones Specific for Mycobacterium tuberculosis

Antigen-specific cytolytic CD4(+) T lymphocytes control Mycobacterium tuberculosis infection by secreting cytokines and by killing macrophages that have phagocytosed the pathogen. However, lysis of the latter cells promotes microbial dissemination, and other macrophages engulf the released bacteria. Subsequently, CD4(+) T-cell-mediated killing of macrophages goes on, and this persistent process may hamper control of infection, unless regulatory mechanisms maintain a subtle balance between lysis of macrophages by cytolytic CD4(+) cells and activation of cytolytic CD4(+) cells by infected macrophages. We asked whether inhibitory molecules expressed by CD4(+) cytolytic T lymphocytes could play a role in such a balance. To this end, human CD4(+) T-cell clones specific for M. tuberculosis were produced that displayed an autologous major histocompatibility complex class II-restricted lytic ability against purified protein derivative (PPD)-pulsed antigen-presenting cells. All T-cell clones expressed CD152 (cytotoxic T-lymphocyte antigen 4 [CTLA-4]) and CD85/leukocyte immunoglobulin-like receptor 1 (LIR-1)/immunoglobulin-like transcript 2 (ILT2) inhibitory receptors, but not CD94 and the killer inhibitory receptor (or killer immunoglobulin-like receptor [KIR]) p58.2. CD3-mediated activation of the clones was inhibited in a redirected killing assay in which CD152 and CD85/LIR-1/ILT2 were cross-linked. Specific antigen-mediated proliferation of the clones was also sharply reduced when CD152 and CD85/LIR-1/ILT2 were cross-linked by specific monoclonal antibody (MAb) followed by goat anti-mouse antiserum. In contrast, blockade of the receptors by specific MAb only increased their proliferation. Production of interleukin 2 (IL-2) and gamma interferon (IFN-γ) by the T-cell clones was also strongly reduced when CD152 and CD85/LIR-1/ILT2 were cross-linked. The lytic activity of the T-cell clones against PPD-pulsed autologous monocytes or Epstein-Barr virus-activated B cells was increased by blockade and decreased by cross-linking of the receptors. These results indicate that CD152 and CD85/LIR-1/ILT2 play a role in the regulation of the antigen-specific activity of CD4(+) cytolytic T lymphocytes against PPD-presenting cells