ABSTRACT
Trichoderma stromaticum, a biocontrol agent of the cacao witches' broom pathogen Moniliophthora perniciosa, has been used in Brazil as part of the integrated pest management of cacao. At the present time, little is known about the effects of T. stromaticum on the modulation of in vitro or in vivo immune responses. The present study examined the interaction of T. stromaticum spores with cellular and molecular components of the immune system following intranasal sensitization of mice. Our results showed that T. stromaticum spores prevented the expression and production of inflammatory mediators in macrophages stimulated with interferon (IFN)-γ plus lipopolysaccharide (LPS) and neutrophils stimulated with phorbol myristate 13-acetate (PMA). Quantitative polymerase chain reaction (qPCR) assays revealed that T. stromaticum spores inhibited the expression of dectin-1 and Toll-like-receptor (TLR)2/TLR4. Intranasal injection of BALB/c mice and subsequent challenge with spores of T. stromaticum induced a discrete inflammatory response in the lungs. Interestingly, the spores inhibited local and systemic production of the regulatory IL-10 and proinflammatory IFN-γ cytokines. In addition the spores presented an antiproliferative effect on spleen cells. These findings showed that the biopesticide T. stromaticum may exert immunosuppressive effects in vitro and in vivo.
Subject(s)
Interferon-gamma/metabolism , Interleukin-10/metabolism , Mycoses/metabolism , Nitric Oxide/metabolism , Phagocytes/metabolism , Trichoderma/pathogenicity , Adaptive Immunity , Animals , Bronchoalveolar Lavage Fluid/immunology , Female , Immunity, Innate , Lectins, C-Type , Lung/metabolism , Membrane Proteins/genetics , Membrane Proteins/metabolism , Mice , Mice, Inbred BALB C , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Nitric Oxide Synthase Type II/metabolism , Pest Control, Biological , Phagocytes/immunology , Phagocytes/microbiology , RNA, Messenger/metabolism , Reactive Oxygen Species/metabolism , Toll-Like Receptor 2/genetics , Toll-Like Receptor 2/metabolism , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/metabolismABSTRACT
Being an intracellular pathogen demands being able to invade a host cell, to circumvent the host immune response and to survive in the intracellular environment. Pore-forming proteins are among the innumerable tools used by intracellular microorganisms to achieve these goals. Remarkably, this seems to be a multipurpose group of proteins that can act in several ways. Making channels may signify entering into host cells, inhibiting phagocytosis, escaping phagosomes or promoting pathogen dissemination. In certain cases, pore-forming proteins are double-edged tools and may benefit the host by eliminating infected cells and/or inducing inflammation.
Subject(s)
Porins/metabolism , Animals , Apoptosis , Bacteria/immunology , Bacteria/metabolism , Bacteria/pathogenicity , Bacterial Infections/immunology , Bacterial Infections/metabolism , Bacterial Infections/microbiology , Bacterial Infections/pathology , Eukaryota/immunology , Eukaryota/metabolism , Eukaryota/pathogenicity , Host-Parasite Interactions , Models, Biological , Phagocytosis , Porins/biosynthesis , Porins/chemistry , Protozoan Infections/immunology , Protozoan Infections/metabolism , Protozoan Infections/parasitology , Protozoan Infections/pathologyABSTRACT
Resumo: Apresenta-se a experiência da implantação da Aprendizagem Baseada em Problemas em Microbiologia no Curso de Medicina da Universidade Federal de Minas Gerais, no contexto de um projeto piloto visando à integração dos ciclos básico e profissional. Descreve-se o processo de implantação e apresentam-se resultados de avaliações em dois semestres sucessivos. Para estas avaliações, foram utilizados questionários respondidos por alunos e depoimentos de tutores em entrevistas informais. Aspectos positivos, como a motivação e a satisfação dos estudantes com a metodologia e o bom desempenho dos tutores, foram evidenciados. Dificuldades com a organização do processo de trabalho em Aprendizagem Baseada em Problemas dentro de um currículo com um outro eixo metodológico estiveram presentes durantes toso o tempo de desenvolvimento do projeto. Conclui-se que a adoção parcial da metodologia representa uma limitação e um desafio a ser superado.
Abstract: This article reports on experience with the Problem-Based Learning methodology (PBL) as part of the undergraduate course in Microbiology in the School of Medicine at the Federal University in Minas Gerais. Implementation and evaluation of the method are described. Students and tutors were interviewed for the evaluation. Some positive aspects like student motivation and satisfaction and goods performance by tutors were found. The main difficulty was working partially with PBL within a curriculum using a traditional teaching approach.
