O papel das respostas imunológicas inata e adaptativa ao SARS-CoV-2: Revisão de literatura / The role of the innate and adaptative immune responses to SARS-CoV-2: Literature review

Introdução: O vírus SARS-CoV-2, causador da COVID-19, tornou- -se a representação de ameaça global ao que diz respeito à saúde pública, à medida que se espalha facilmente. A COVID-19 pode gerar desde um quadro assintomático até sinais e sintomas envolvendo os sistemas respiratório, hepático, neurológico, podendo, inclusive, levar à morte. O sistema imunológico possui papel fundamental no combate às infecções e sua atuação pode definir o quadro clínico, seja assintomático, leve, grave ou fatal. Objetivo: Descrever o papel das respostas imunológicas inata e adaptativa ao SARS-CoV-2. Metodologia: O estudo caracterizou-se por levantamento bibliográfico utilizando-se artigos científicos indexados nas bases de dados online PubMED, Medline, Scielo e Google Acadêmico, no período compreendido entre 2019 e 2020 Para a filtragem das publicações foram utilizados os seguintes descritores em português/inglês: COVID-19, SARS-CoV-2, Sistema imunológico, Resposta inata e Resposta adaptativa. Após filtragem, 42 artigos científicos foram selecionados. Resultados: O SARS-CoV-2 infecta as células do indivíduo ao reconhecer a enzima ECA2 ou a proteína CD147 e suas proteínas virais prejudicam a resposta imune à medida que diminuem a síntese de IFN1, ativam a via NF-kB, aumentam a síntese de citocinas pró-inflamatórias e aumentam a necroptose. Linfócitos T CD4+ possuem papel essencial na ativação de Linfócitos B e sua consequente síntese de anticorpos monoclonais. Linfócitos T CD8+ citotóxicos são capazes de dizimar células infectadas. Entretanto, estes eventos podem levar à resposta inflamatória exacerbada e à tempestade de citocinas, o que pode ser prejudicial nas infecções por SARS- -CoV-2, já que agravam sintomas e promovem alterações sistêmicas. Conclusão: Conhecido que Linfócitos T e B são ativados por peptídeos virais e que esta ativação promove a liberação de mediadores inflamatórios-chave e anticorpos monoclonais, e sabendo-se que a tempestade de citocinas inflamatórias pode agravar o quadro clínico do paciente infectado, faz-se necessário reconhecer a importância do sistema imunológico no combate à infecção da COVID-19.

Introduction: The SARS-CoV-2 virus, which causes COVID-19, has become the representation of global threat to public health, as it spreads easily, without efficient resources to control its spread until the present moment. COVID-19 can generate from an asymptomatic condition to signs and symptoms involving the respiratory, hepatic, neurological systems, and can even lead to death. The immune system has a fundamental role in fighting infections and its performance can define the clinical condition, either asymptomatic, mild, severe or fatal. Objective: To describe the role of innate and adaptive immune responses to SARS-CoV-2. Methodology: The study was characterized by a bibliographic survey, using scientific articles indexed in the online databases PubMED, Medline, Scielo and Google Scholar, in the period between 2019 and 2020. For filtering publications, the following descriptors were used in Portuguese/ English COVID-19, SARS-CoV-2, Immune system, Innate response and Adaptative response. After filtering, 42 scientific articles were selected. Results: SARS-CoV-2 infects the individual's cells by recognizing the ECA2 enzyme or the CD147 protein and its viral proteins impair the immune response as they decrease IFN1 synthesis, activate the NF-kB pathway, increase pro cytokine synthesis -inflammatory and increase necroptosis. CD4 + T lymphocytes play an essential role in the activation of B lymphocytes and their consequent synthesis of monoclonal antibodies. Cytotoxic CD8 + T lymphocytes are capable of decimating infected cells. However, these events can lead to an exacerbated inflammatory response and a cytokine storm, which can be harmful in SARS-CoV-2 infections, as they worsen symptoms and promote systemic changes. Conclusion: Known that T and B lymphocytes are activated by viral peptides and that this activation promotes the release of key inflammatory mediators and monoclonal antibodies, and knowing that the storm of inflammatory cytokines can worsen the clinical condition of the infected patient, it is necessary to recognize the importance of the immune system in combating the infection of COVID-19.

Alterations induced in the ileum of mice upon inoculation with different species of Leishmania: a preliminary study

Abstract INTRODUCTION: Leishmania species cause skin, mucosal, and disseminated lesions. We studied the effects of three Leishmania species on ileal morphology in mice. METHODS: BALB/c mice were intraperitoneally inoculated with Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis, and Leishmania (Leishmania) major (4 animals/group). After 72h, the ilea were collected and histologically processed. RESULTS: Following inoculation, the goblet cell and intraepithelial lymphocyte populations increased, while Paneth cell number and crypt width decreased. In addition, enterocyte size, villi height, and mucosa, submucosa, and muscular tunic thickness increased. CONCLUSIONS: Leishmania modified the quantity of cells in and morphology of mice ilea.

El uso de los agrotoxicos y su afectación al sistema inmune: un tema de interés actual / The use of pesticides and affectation on immune system: an issue of current interest

Actualmente se conoce que nos enfrentamos a una variedad de agentes químicos (agrotóxicos) como ser los plaguicidas, pesticidas, herbicidas, porque están presentes en el ambiente, en los alimentos, en el agua, en bajas concentraciones, pero que a la larga inducen efectos nocivos en la salud. Se utilizan estos agentes químicos en los programas públicos de salud, para la erradicación de criaderos de mosquitos transmisores de enfermedades como por ejemplo el vector de la malaria y se utilizan también en la agricultura, principalmente para el control de plagas, que afectan grandemente en la producción de productos alimenticios. La aplicación indiscriminada de estos agrotóxicos, ahora en países como el nuestro, está causando una grave contaminación ambiental, aumentando los potenciales riesgos para la salud, porque estos tóxicos se difunden rápidamente en el medio ambiente por lo que es necesario conocer los estudios realizados a nivel mundial de los potenciales riesgos para la salud humana. La mayoría de los estudios se han realizado en animales de experimentación. La inmunotoxicidad no es solo el resultado del contacto con grandes dosis de un agrotóxicos, sino también de la exposición crónica a bajas dosis, durante largos periodos de tiempo. Las investigaciones sobre la toxicidad de los plaguicidas se han centrado en observar: alteraciones enzimáticas, efectos patológicos, mutagénicos y cancerígenos en poblaciones humanas expuestas y solo recientemente se han estudiado los efectos de los plaguicidas sobre la respuesta inmune. Estos estudios no tienen conclusiones implícitas sobre la inmunotoxicidad, sin embargo, dejan claramente establecido que los efectos lentos o retrasados de los agrotóxicos sobre la salud y principalmente sobre el sistema inmune, a pesar de que son más difíciles de detectar, son los más importantes, porque dan lugar a diferentes tipos de alteraciones como la susceptibilidad a enfermedades, diagnosticadas tardíamente las cuales en muchos casos no tiene un pronóstico favorable.

Currently it is known that we face a variety of chemicals (pesticides) such as pesticides, pesticides, herbicides, because they are present in the environment, in food, in water, in low concentrations, but eventually induce effects harmful to health. These chemicals are used in public health programs for the eradication of breeding sites for mosquitoes transmitting diseases such as malaria vector and are also used in agriculture, mainly for pest control, which greatly affect the food production. The indiscriminate application of these pesticides, now in countries like ours, is causing severe environmental pollution, increasing the potential health risks because these toxic diffuse rapidly in the environment so it is necessary to know the level studies world of potential risks to human health. Most studies have been conducted in experimental animals. Immunotoxicity is not only the result of contact with large doses of pesticides, but chronic exposure to low doses over long periods of time.Researches on the toxicity of pesticides have focused on observing: enzyme abnormalities, pathological effects, mutagenic and carcinogenic in human populations exposed and only recently have studied the effects of pesticides on the immune response.These studies have implied conclusions on immunotoxicity, however, they leave it clear that the slow effects or delayed of pesticides on health and primarily on the immune system, although they are more difficult to detect, are the most important, because they give rise to different types of disturbances such as disease susceptibility, belatedly diagnosed which in many cases have a favorable prognosis.

Resistência contra ectoparasitas em bovinos da raça Crioula Lageana e meio-sangue Angus avaliada em condições naturais / Resistence against ectoparasites in CriouloLageano and crossbred Angus cattle in southern Brazil under natural conditions

Este trabalho foi desenvolvido com o objetivo de avaliar a resistência aos ectoparasitas em bovinos jovens da raça Crioula Lageana e meio-sangue Angus em condições naturais. Foram utilizados 10 machos castrados em cada grupo, recém desmamados (6-8 meses) e mantidos sob as mesmas condições de manejo, em pastagens cultivadas de inverno e verão, no município de Monte Castelo - SC, sofrendo infestação natural por ectoparasitas. A cada 28 dias, fêmeas de carrapatos (Rhipicephalus (Boophilus) microplus) com tamanho acima de 4 mm foram quantificadas nos dois lados do corpo de cada animal, bem como os nódulos com larvas de Dermatobia hominis. A espessura da capa do pelame foi também avaliada a cada coleta e os animais foram classificados quanto à coloração do pelame. Os animais da raça Crioula Lageana foram mais resistentes às infestações por D. hominis e R. microplus. Não houve diferença entre a disposição de carrapatos e bernes conforme os lados direito e esquerdo dos animais. Os animais de pelagem escura albergaram a maior porcentagem de ectoparasitas nos grupos avaliados.

This study was carried out to evaluate the breed resistance against ectoparasites infestations in Crioula Lageana and crossbred Angus male calves under natural condition. Ten weaned and neutered male calves (6-8 months) of each group were kept together in winter and summer pastures in Monte Castelo, Santa Catarina State. Every 28 days, female ticks (Rhipicephalus (Boophilus) microplus) more than 4 mm long were counted on the right and left side of the body of each animal, as well as the D. hominis nodules. Coat thickness also was measured at each sampling and all animals were classified according coat color. Crioula Lageana group was less infested by D. hominis than crossbred Angus in five times and by ticks in the infestation peak (P<0.05). There were no differences in the distribution of the ticks and grubs between animal body sides. Dark-haired animal in both groups were the most susceptible.