TNF-TNFR1 signaling enhances the protection against Neospora caninum infection

Neospora caninum is a protozoan associated with abortions in ruminants and neuromuscular disease in dogs. Classically, the immune response against apicomplexan parasites is characterized by the production of proinflammatory cytokines, such as IL-12, IFN-γ and TNF. TNF is mainly produced during the acute phases of the infections and binds to TNF receptor 1 (CD120a, p55, TNFR1) activating a variety of cells, hence playing an important role in the induction of the inflammatory process against diverse pathogens. Thus, in this study, we aimed to evaluate the role of TNF in cellular and humoral immune responses during N. caninum infection. For this purpose, we used a mouse model of infection based on wildtype (WT) and genetically deficient C57BL/6 mice in TNFR1 (Tnfr1-/-). We observed that Tnfr1-/- mice presented higher mortality associated with inflammatory lesions and increased parasite burden in the brain after the infection with N. caninum tachyzoites. Moreover, Tnfr1-/- mice showed a reduction in nitric oxide (NO) levels in vivo. We also observed that Tnfr1-/- mice showed enhanced serum concentration of antigen-specific IgG2 subclass, while IgG1 production was significantly reduced compared to WT mice, suggesting that TNFR1 is required for regular IgG subclass production and antigen recognition. Based on our results, we conclude that the TNF-TNFR1 complex is crucial for mediating host resistance during the infection by N. caninum

Subjective sleep pattern in hospitalized patients

Objective: To evaluate the subjective sleep pattern in hospitalized patients. Methods: This is a cross-sectional design developed with 230 patients in a university hospital in northeastern Brazil from September 2017 to March 2018. We included patients 18 years old or older, hospitalized for a minimum of 48 hours and a maximum of five days, with stable clinical conditions and preserved guidance. For data collection, a structured questionnaire was used and the subjective sleep pattern was assessed using Visual Analog Sleep Scales. Univariate and bivariate statistics were calculated using IBM® SPSS® software, version 23.0. Results: In the hospitalization, the Disorder, Effectiveness, and Supplementation scales reached scores of 208.7 points, 353.8 points, and 62.9 points, respectively. The clinical characteristics that interfered with sleep were the practice of regular physical activity (p = 0.024) and a higher body mass index (p = 0.033). We also observed statistically significant differences between VAS scores and factors influencing sleep. Conclusion: There was a certain level of sleep disturbance during the hospitalization period, and consequently the need for sleep supplementation during the day. We also observed that some factors negatively influenced the quality of hospital sleep

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Role of innate recognition pathways in the resistance to oral infection by Neospora caninum in mice

Neospora caninum is an obligate intracellular parasite with worldwide distribution that causes abortions in cattle and billionaire losses in livestock. The investigation of immune response against this infection usually adopts parenteral infection in murine models. However, it is essential to understand the immune mechanisms after oral infection wich accurately mimics natural condition. Th1 adaptative immune response is crucial to protect against this intracellular protozoan, wich is mainly regulated by IFN-γ production. Thus, in this work, we aimed to evaluate the immune response triggered by N. caninum oral infection in mice, focusing in the IFN- γ production induced by innate pathway TLR-MyD88 and inflamassome. For this purpose, we used C57BL/6 mice orally infected with tachyzoites after neutralization of the gastric pH. We analyzed the survival, tissue lesions, cytokine production, and specific antibody production in infected mice. We observed that WT mice infected by oral route presented higher levels of serum specific IgG, composed mainly by IgG2 antibodies. DNA of the parasite was detected mainly in the distal jejunum and ileum, however, no histological alterations were detected through the gut. Meanwhile, acute inflammatory lesions were observed in livers and lungs of orally infected mice, related with the presence, in situ, of parasite DNA and IFN-γ production. In order to analyze the role of these key cytokine, we infected IFN-γ genetically deficient mice with N. caninum tachyzoites by gavage. We observed that IFN γ-/- mice presented reduced signs of morbidity during the beginning of infection. However, after six days of infection, IFN γ-/- mice succumbed quickly the infection, with no signs of inflammatory lesions in analyzed tissues. After this results, we investigated the pathway responsible to IFN-γ production during oral infection using MyD88-/- and Caspase-1/11-/- mice infected with N. caninum. A significant reduction in the IFN-γ production in Caspase-1/11-/- mice was observed in this experiment, whereas MyD88 deficient mice did not present alterations in the levels of this cytokine. These findings are supported by histological analyses that demonstrated a reduction of lung and liver tissue lesions in Caspase-1/11-/- mice, similar to the result previously observed in the absence of IFN-γ. In conclusion, this work demonstrated the quick passage of the N. caninum protozoa into the small intestine of mice, and then injuring abdominal and thoracic organs through replicative and inflammatory processes mediated by IFN-γ. Also, this cytokine is induced by the activation of the inflamassome complex. Overall, we can get the possibility to enhance the control of pathogenicity induced by N. caninum infection.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorCNPq - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPEMIG - Fundação de Amparo a Pesquisa do Estado de Minas GeraisTese (Doutorado)Neospora caninum é um parasito intracelular obrigatório com distribuição mundial, gerando abortamentos em bovinos e perdas bilionárias anuais na área da produção animal. Pesquisas sobre a resposta imune contra esta infecção adotam geralmente modelos murinos através da infecção parenteral. Entretanto, compreender os mecanismos imunológicos após a infecção oral é essencial, uma vez que mimetiza a infecção natural com maior precisão. A resposta imune contra protozoários intracelulares é baseada em respostas imunes de padrão Th1, reguladas através da produção de IFN-γ. Assim, neste trabalho, objetivou-se avaliar a resposta imune desencadeada pela infecção oral por N. caninum em camundongos, com especial atenção na produção de IFN-γ através de vias inatas TLR-MyD88 e Inflamassoma. Para estes experimentos, foram utilizados camundongos C57BL/6 infectados com taquizoítos pela via oral, após o bloqueio do pH estomacal. Os camundongos foram analisados quanto à sobrevivência, lesões teciduais, produção de citocinas e produção de anticorpos específicos. Observamos que camundongos WT infectados via oral apresentaram níveis crescentes de IgG sérica específica, composta principalmente por anticorpos IgG2. DNA de parasitos foi detectado principalmente no jejuno distal e no íleo dos camundongos, embora nenhuma alteração histológica tenha sido detectada em todo o intestino. No entanto, lesões inflamatórias agudas foram observadas nos fígados e pulmões de camundongos infectados por via oral, associados à presença, in situ, de DNA de parasitos e produção de IFN-γ. A fim de analisar o papel dessa citocina chave, nós infectamos camundongos geneticamente deficientes em IFN-γ com taquizoítos de N. caninum utilizando a mesma via. Observamos que camundongos IFN-γ-/- apresentaram pouco ou nenhum sinal de morbidade durante os primeiros dias de infecção. No entanto, a partir do sexto dia, camundongos IFN-γ-/- sucumbiram rapidamente à infecção, sem sinais de lesão inflamatória nos tecidos analisados. Com tal confirmação, nós investigamos a via responsável pela produção da citocina IFN-γ durante a infecção oral, utilizando camundongos deficientes em MyD88 e Caspase-1/11 infectados com N. caninum. Foi observado neste experimento uma redução significativa da produção de IFN-γ em camundongos Caspase-1/11-/-, enquanto camundongos deficientes em MyD88 não apresentaram alterações nos níveis desta citocina. Tal resultado foi corroborado pela análise histológica dos tecidos, com redução da lesão de tecidos pulmonares e hepáticos em camundongos Caspase-1/11-/-, de modo semelhante ao anteriormente observado na ausência de IFN-γ. Em conclusão os resultados aqui apresentados demonstram a rápida passagem do protozoário N. caninum pelo intestino delgado de camundongos, lesionando órgãos abdominais e torácicos por meio de processos replicativos e inflamatórios mediados por IFN-γ, induzido pela ativação do complexo Inflamassoma. Por meio dos conhecimentos gerados, abre-se a possibilidade de melhor controle da patogenia induzida pela infecção por N. caninum

Role of TLR2/MyD88 in the production of specific IgM and IgG antibodies during the immunization of mice against Neospora caninum

Neospora caninum is a parasite relevant to the veterinary field. Innate and adaptive responses against N. caninum induce effector mechanisms that limit parasite replication, but little is known about their role in humoral response. Our work aimed to verify whether key molecules in the TLR2/MyD88-mediated response would impact the production of specific IgM and IgG antibodies in mice during immunization with soluble antigens of N. caninum. We observed that lack of IFN-gamma did not negatively affect the production of specific antibodies. However, mice genetically deficient in Toll-like receptor 2, Myeloid differentiation factor 88, Interleukin 12 and inducible nitric oxide synthase presented significant decrease in antibody levels against N. caninum antigens, which also reflected in the diversity of the antigen recognized by their serum. In that sense, we show here that molecules within this innate recognition pathway may present a direct impact in the induction of an antibody response against N. caninum

In vitro and in vivo models for monkeypox

Summary: The emergence and rapid spread outside of monkeypox virus (MPXV) to non-endemic areas has led to another global health emergency in the midst of the COVID-19 pandemic. The scientific community has sought to rapidly develop in vitro and in vivo models that could be applied in research with MPXV. In vitro models include two-dimensional (2D) cultures of immortalized cell lines or primary cells and three-dimensional (3D) cultures. In vitro models are considered cost-effective and can be done in highly controlled conditions; however, they do not always resemble physiological conditions. In this way, several in vivo models are being characterized to meet the growing demand for new studies related to MPXV. In this review, we summarize the main MPXV models that have already been developed and discuss how they can contribute to advance the understanding of its pathogenesis, replication, and transmission, as well as identifying antivirals to treat infected patients