BACKGROUND Non-human primates contribute to the spread of the yellow fever virus (YFV) and the establishment of transmission cycles in endemic areas. OBJECTIVE To describe the severe histopathological aspects of YFV infection, 10 squirrel monkeys were infected with YFV and blood, brain, liver, kidney, spleen, heart, lung, lymph node and stomach were collected at 1-7, 10, 20 and 30 days post-infection (dpi). METHODS Histopathological analysis and detection of the genome and viral antigens and neutralising antibodies were performed by RT-PCR, immunohistochemistry and neutralisation test, respectively. FINDINGS Only one animal died from the experimental infection. The genome and viral antigens were detected in all investigated organs (1-30 dpi) and the neutralising antibodies from seven to 30 dpi. The brain contained perivascular haemorrhage (6 dpi); in the liver, midzonal haemorrhage and lytic necrosis (6 dpi) were observed. The kidney had bleeding in the Bowman’s capsule and tubular necrosis (6 dpi). Pyknotic lymphocytes were observed in the spleen (1-20 dpi), the lung had haemorrhage (2-6 dpi), in the endocardium it contained nuclear pyknosis and necrosis (2-3 dpi) and the stomach contained blood in the lumen (6 dpi). MAIN FINDINGS Squirrel monkeys reliably reproduced the responses observed in human cases of yellow fever and, therefore, constitute an excellent experimental model for studies on the pathophysiology of the disease.

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Antineutrophil autoantibodies reacting with cytoplasmic antigens are associated with various types of vasculitides, whereas antibodies reacting with neutrophil membrane antigens are mostly related to autoimmune neutropenias. The aim of this study was the investigation of the effect of monoclonal antibodies (MoAbs) reacting with surface and cytoplasmic antigens of polymorphonuclear leukocytes (PMN) known to be targets for autoantibodies in human diseases. Blood of healthy volunteers was tested for several phagocytic functions in the presence of MoAbs against surface (CD16, CD11b, CD18, NB1) and cytoplasmic (proteinase 3; PR3) molecules. Candidacidal activity was significantly inhibited in the presence of all MoAbs but isotypic control. Phagocytic activity was inhibited by anti-CD11b and/or anti-CD18 MoAbs. Zymosan-induced chemiluminescence was reduced by MoAbs anti-CD16, CD18, and NB1, enhanced by anti-PR3 MoAb, and less enhanced by anti-CD11b. In conclusion, antimembrane antibodies diminished phagocytic functions at multiple steps; in contrast, anticytoplasmic MoAb promoted activation of oxidative burst in addition to impairment of microbicidal activity. This fact may be related to different pathogenic aspects of diseases associated with antimembrane and anticytoplasmic antibodies.

Objetivo: Descrever a infecção pelo Vírus Zika (VZIK) em células progenitoras e desordem em expressão gênica a partir de seus mediadores, os RNAs não-codificantes (ncRNAs). Métodos: Estudo observacional, de base transversal do tipo revisão integrativa. Foram selecionados artigos disponibilizados pelas plataformas: Nature, Medical Literature Analysis and Retrieval System Online (Medline), Science Direct e Repositório Digital do Instituto Evandro Chagas (Patuá), fundamentados pela busca de hipóteses relacionadas às alterações na expressão de ncRNAs, resultando em alterações fisiológicas em células progenitoras a partir da infecção por VZIK. Resultados: Foram obtidos 72 estudos relacionados a expressão de ncRNAs em infecções por vírus Zika, sendo definidos 8, que retratavam a proposta do tema. Estes, estabeleciam uma verossimilhança na abordagem do objeto de pesquisa, baseada na função dos ncRNAs, relação epigenética em infecção por VZIK e ativação de mediadores imunológicos, descrevendo a expressão de produtos gênicos associados a processos celulares correspondentes aos recursos de defesa do hospedeiro e aos mecanismos de replicação viral. Considerações Finais: Assim, observou-se a importância de estudos que proporcionem a contribuição técnica experimental, sobre os mecanismos de replicação viral, tropismo celular, atividade imunogenética, de modo a fomentar a contribuição científica para o controle do VZIK.

Objectives:The Brazillian Health Ministry demands an continuous following of lymphocytes CD4+ and CD8+ levels on HIV serum positive patients by Flow Cytometry methodology. An alternative assay has been developed by Bio-Manguinhos using four monoclonal antibodies labeled with differents fluorochromes. In this context, the aim of this work is the establishment of a conjugation process of anti-CD4 with Phycoerythrin -Cyanin 7 (PECy7) fluorochrome, once this conjugate is essential to compose an immunophenotyping assay with four lymphocytes markers. Methods:The conjugation process was based on Roederer´s protocol. In the first step, Cyanin 7 (Cy7) reacted with free amino groups from Phycoerythrin (PE) to produce the Tandem fluorochrome. PECy7 was derivatizated with the crosslinking agent Succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC). Meanwhile the antibody anti-CD4 was partially reduced with ditiothreitol (DTT) and further added to the activated Tandem. The conjugation reaction was stopped with N-Ethylmaleimide (NEM) to block non reacted sulphydril groups. Monoclonal antibody (anti-CD4), PE and the anti-CD4-PECy7 conjugate were evaluated by gradient-SDS-PAGE (8 -25%) , IEF-PAGE (3.0 -9.0) and Size Exclusion Chromatography (SEC -Superdex 200) as process control to assure homogeneity of reactants and products. Spectrophotometric absortions at 280nm, 565 nm, 620nm and 755nm were used to follow each step. At last, the anti-CD4-PECy7 conjugate was analysed by flow cytometry (FC). Results: The anti-CD4 and PE preparations were considered homogeneous by denaturing gel electrophoresis and SEC analysis. The fluorochromes PE and Cy7 presented UV-VIS spectra seemed to that described in the literature. No bleeding signal of PE was observed 127 in the flow citometry analysis of anti-CD4-PECy7. Moreover, the anti-CD4-PECy7 conjugate presented similar FC results to those obtained by Becton and Dickinson's anti-CD4 conjugate used as gold standard. Conclusion:The absence of bleeding signal of PE by FC analysis suggests that all phycoeritrin emission light was absorbed by Cy7 molecules and this fact demonstrates the tandem synthesis was successful. Several check points must be performed as process control to ensure the reprodutibility of anti-CD4-PECy7 production. The behaviour of the anti-CD4-PECy7 in FC assay demonstrates that this conjugate can be used in the composition of an immunophenotyping kit for TCD4 + lymphocyte count as fourth marker.