Safety and immunogenicity of 17DD attenuated yellow fever vaccine in howler monkeys (Alouatta spp.).

BACKGROUND: Alouatta spp. are highly susceptible to yellow fever (YF) infection and develop an often fatal disease. The threat posed by an outbreak started in 2016 leads us to investigate vaccination as a potential tool in preventing YF in non-human primates (NHP). METHODS: Susceptible howler monkeys were immunized with three different concentrations of the human Brazilian commercial YF17DD vaccine. Post-vaccination viremia/RNAemia, immunogenicity, and safety were characterized. RESULTS: The vaccine did not produce YF clinical manifestations in any of the NHPs. After immunization, all animals seroconverted demonstrating the ability of the YF vaccine to induce humoral response in Alouatta species. CONCLUSIONS: The present work has demonstrated the safe and immunogenic profile of the existing YF 17DD vaccine in howler monkeys. This knowledge may support further studies with other susceptible monkey species and provide a possible solution for controlling epizootics and preventing the devastation of endangered species.

Different aspects of platelet evaluation in dengue: Measurement of circulating mediators, ability to interact with the virus, the degree of activation and quantification of intraplatelet protein content.

Platelets play a role in hemostasis, coagulation, angiogenesis, inflammation and immune response is one of the most affected cells in dengue. Here we describe some aspects of platelets by observing their specific circulating mediators, the ability to interact with the virus and morphological consequences of this interaction, activation markers and intraplatelet protein contents in dengue. We conducted this study using dengue-patients as well as healthy donors. Immunoenzymatic assay, flow cytometry, transmission electron microscopy and intraplatelet proteins expression assays were carried out. Briefly, we found an increase in sCD62L, NO or TBX2 ratio in platelet count, mostly in patients with the worse clinical outcome. After in vitro DENV infection or during natural infection, platelets underwent morphological alteration with increased expression of platelet activation markers, particularly in natural infections. Analysis of intraplatelet protein contents revealed different angiogenic and inflammatory profiles, maintaining or not extracellular matrix integrity between DF and DFWS patients. Thus, platelets are frequently affected by dengue, either by altering their own functionality, as "carrier" of the virus, or as an antiviral and mediator-secreting effector cell. Thus, strategies aimed at recovering platelet amounts in dengue seem to be essential for a better clinical outcome of the patients.

Avaliação do perfil de mediadores séricos e proteínas intraplaquetárias em relação à plaquetopenia em pacientes infectados pelo vírus dengue / Evaluation of serum mediators profile and intraplatelet proteins in respect to thrombocytopenia in patients infected with dengue virus

Plaquetas são fragmentos celulares derivados dos megacariócitos, que desempenham papel na hemostasia, coagulação, angiogênese, inflamação e resposta imune. Na infecção humana pelo Vírus Dengue (DENV), plaquetas constituem uma das populações celulares mais afetadas devido à plaquetopenia e disfunção plaquetária. O objetivo deste trabalho foi investigar a influência de citocinas, quimiocina e fatores de crescimento séricos e de proteínas intraplaquetárias relacionadas à angiogênese, coagulação, regulação da matriz extracelular e inflamação na plaquetopenia de pacientes infectados pelo DENV. Para tal, realizamos: (i) estudo populacional de pacientes e obtenção de soro e plaquetas em 2013, (ii) ensaios multiplex de micrarranjo líquido para quantificação dos níveis séricos de citocinas, quimiocina e fatores de crescimento e (iii) ensaio de determinação do perfil de expressão 55 proteínas intraplaquetárias. Quarenta e três pacientes DENV foram confirmados, com predominância do DENV-4. Independente da forma clínica, pacientes DENV apresentaram níveis séricos elevados de IL-10, TNF-alfa, CXCL8/IL-8, mas não de IL-1beta e IFN-gama quando comparados aos controles sadios. Análises estatísticas demonstraram que níveis de IL-10 e IFN-gama apresentaram correlação, respectivamente inversa e direta com a contagem de plaquetas. Ainda, IL-10 diretamente com leucócitos e linfócitos e TNF-alfa com linfócitos. Vinte e cinco proteínas intraplaquetárias foram quantificadas, mas apenas cinco delas, PDGF-AA, TGF-beta1, HGF, IGFBP-1 e Angiopoetina-1, apresentaram correlação direta com a contagem de plaquetas nos pacientes DENV. A quantificação sérica de PDGF e VEGF demostrou que ambos estavam diminuídos no grupo DENV mais trombocitopênico...

Platelets are cell fragments derived from megakaryocytes, which play a role in hemostasis, coagulation, angiogenesis, inflammation and immune response. In human infection with dengue virus (DENV), platelets are one of the most affected cell populations due to thrombocytopeniaand platelet dysfunction. The objective of this study was to investigate the influence of serum cytokines, chemokines, intraplatelet growth factors and proteins related to angiogenesis, coagulation, regulation of extracellular matrix and inflammation in thrombocytopenia of patientsinfected with DENV. For this purpose, we conducted: (i) population study of patients and obtaining their serum and platelets in 2013, (ii) liquid microarray multiplex assays for quantitationof serum levels of cytokines, chemokine, and growth factors, and (iii) assay for determiningexpression profile of 55 intraplapletelet proteins. Forty-three DENV patients were confirmed, with a predominance of DENV-4. Regardless of type of DENV, levels of IL-10, TNF-alfa, CXCL8 /IL-8, but not IL-1beta and IFN-gama were higher on serum of patients compared to healthy individuals. Statistical analyses showed that levels of IL-10 and IFN-gama presented correlation, respectively, inverse and direct with platelet count. Furthermore, IL-10 was directly correlated with leukocytes, lymphocytes, TNF-alfa and with lymphocytes. Twenty-five intraplatelet proteins were quantified, but only five of them, PDGF-AA, TGF-beta1, HGF, angiopoietin-1 and IGFBP-1 weredirectly correlated with platelet count in DENV patients. Both levels of PDGF and VEGF were decreased in group of DENV thrombocytopenic...