effect of bovine viral diarrhea virus on bovine monocyte phenotype

Bovine viral diarrhea virus [BVDV] is an economically important pathogen of the livestock industry worldwide. BVDV is classified into cytopathic [cp] and noncytopathic [ncp], depending on its effects on cultured cells. BVDV is known to alter the host's immune response. Of this, major histocompatibility complex [MHC] class II molecules play a central role in the development and function of the immune system, and are comprised of two types, DR and DQ, in cattle. In this study, we investigated the expression of MHC class II on monocytes infected with ncp BVDV1 or ncp BVDV2. Using flow cytometry [P<0.01], mRNA level quantification [quantitative real time RT-PCR, P<0.01], and western blot [P<0.001], we found that the expressions of MHC class IIDQ was significantly decreased in ncp BVDV2-infected monocytes compared with that in ncp BVDV1-infected cells. Furthermore, interferon gamma [IFN gamma] production was markedly decreased in ncp BVDV2-infected monocytes [P<0.001] compared to those with ncp BVDV1 infection. These findings suggest that ncp BVDV2 causes reduced expressions of MHC class II DQ and a decreased production of IFN gamma, resulting in evasion of immune recognition and suppression of the antiviral defense mechanism of the innate immune response. Consequently, the results demonstrate that ncp BVDV1 and ncp BVDV2 interact differently with the host innate immune response. Thus, our data provide insight into the mechanism by which, unlike ncp BVDV1, ncp BVDV2 impairs antigen presentation, fails to control the viral infection, and causes more severe disease

Percepção dos graduandos de enfermagem sobre o seu envelhecimento / Percepción de los estudiantes de enfermería sobre lo proprio envejecimiento / Perception of nursing undergraduate students on self-aging

RESUMO Objetivo: analisar a percepção dos graduandos de enfermagem sobre o próprio envelhecimento. Método: pesquisa de abordagem qualitativa, realizada em agosto e setembro de 2011, com 18 graduandos de enfermagem de uma Universidade pública de Salvador (Bahia). Os depoimentos foram analisados por meio da Análise de Conteúdo. Resultados: apreendeu-se o núcleo temático: Percepção do graduando de enfermagem sobre o próprio envelhecimento e, a partir deste, emergiram duas subcategorias: A) O Não Pensar; B) O contexto influenciando no processo. Conclusão: os graduandos revelam que o envelhecimento está intrínseco ao desenvolvimento humano, e possui o vínculo familiar, a espiritualidade e atividade física como ferramentas fundamentais para um envelhecimento ativo. Entretanto, os mesmos relatam que, o modo de vida acelerado e estressante vivido na sociedade possibilita inserir hábitos considerados inadequados, como o consumo de “fast food” e álcool, que trazem influências negativas para o próprio processo de envelhecimento. .

RESUMEN Objetivo: analizar la percepción de los estudiantes de enfermería sobre su proprio envejecimiento. Método: estudio cualitativo, realizado en agosto y septiembre de 2011, con 18 estudiantes de enfermería de una universidad pública en Salvador/Bahia. Los datos fueron analizados através de análisis de contenido. Resultado: incautados el tema central: Percepción de alumnos de enfermería sobre su propio envejecimiento y de esto surgieron dos subcategorías: A) No creo; B) El contexto influye en el proceso. Conclusión: los estudiantes revelan que el envejecimiento es intrínseco al desarrollo humano, y tiene los vínculos familiares, la espiritualidad y la actividad física como herramienta clave para el envejecimiento activo. Sin embargo, el mismo informe que, debido a la forma de vida que se vive en la sociedad de ritmo rápido y estresante permite insertar hábitos considerados inadecuados, como el consumo de “comida rápida” y el alcohol y convertirse en influencias negativas para su propio proceso tuvo como objetivo analizar de los estudiantes de enfermería su propio envejecimiento. .

ABSTRACT Objective: to analyze the perceptions of nursing undergraduate students on their self-aging process. Method: qualitative study carried out between August and September, 2011 with 18 nursing undergraduate students of a public university in Salvador, Bahia. The interviews were analyzed by means of the Content Analysis method. Results: the following thematic concept was apprehended: Perceptions of nursing undergraduates on their self-aging, which generated two subcategories: A) The “don’t think about it” process; B) The context infl uencing the process. Conclusion: undergraduates reveal that the aging process is an intrinsic factor to human development. Family ties, spirituality and physical activity would be key mechanisms toward active aging. However, students also reported that their accelerated and stressed social lifestyles led to inadequate habits, such as the consumption of fast food and alcohol, which become negative infl uences in their aging process. .

Effects of Epstein-Barr virus on the development of dendritic cells derived from cord blood monocytes: an essential role for apoptosis

OBJECTIVE: Epstein-Barr virus (EBV) is a ubiquitous human γ-herpes virus, which can adapt and evade host immune defense. Dendritic cells (DCs) play a pivotal role in the initiation and maintenance of immune responses. This study investigated the effects of EBV on cord blood monocytes derived DCs (CBDC). METHODS: Monocytes were isolated from cord blood and cultured in medium containing recombinant IL-4 and GM-CSF to induce DCs development. B95-8 supernatant was added in monocytes culture medium for EBV infection at day 0. Phenotypic characterization of DCs, apoptotic cells, and mitochondrial membrane potential (MMP) were detected by flow cytometry. The morphology was observed by Hoechst 33258 staining and TUNEL staining, the expression of X-linked inhibitor of apoptosis protein (XIAP) was detected by Western blotting assay and caspase 3, 8 and 9 activity was measured. RESULTS: Phenotypic characterization of DCs was changed in EBV-treated group. Chromatin condensation and DNA fragmentation were observed in EBV induced CBDC apoptosis. In addition, caspase 3, caspase 8, and caspase 9 activation were enhanced in the EBV-treated group. This was accompanied by the loss of MMP. Furthermore, XIAP expression was down-regulated in the EBV-treated group and compared to mock-infected group. CONCLUSION: These results suggested that EBV could inhibit CBDC phenotypic differentiation, and induce CBDC apoptosis in caspase-dependent manner with involvement of the mitochondrial pathway. This might help EBV to evade host immune responses to establish persistent infection.

Dengue-2 infection and the induction of apoptosis in human primary monocytes

Monocytes/macrophages are important targets for dengue virus (DENV) replication; they induce inflammatory mediators and are sources of viral dissemination in the initial phase of the disease. Apoptosis is an active process of cellular destruction genetically regulated, in which a complex enzymatic pathway is activated and may be trigged by many viral infections. Since the mechanisms of apoptotic induction in DENV-infected target cells are not yet defined, we investigated the virus-cell interaction using a model of primary human monocyte infection with DENV-2 with the aim of identifying apoptotic markers. Cultures analyzed by flow cytometry and confocal microscopy yielded DENV antigen positive cells with rates that peaked at the second day post infection (p.i.), decayed afterwards and produced the apoptosis-related cytokines TNF-á and IL-10. Phosphatidylserine, an early marker for apoptosis, was increased at the cell surface and the Fas death receptor was upregulated at the second day p.i. at significantly higher rates in DENV infected cell cultures than controls. However, no detectable changes were observed in the expression of the anti-apoptotic protein Bcl-2 in infected cultures. Our data support virus modulation of extrinsic apoptotic factors in the in vitro model of human monocyte DENV-2 infection. DENV may be interfering in activation and death mechanisms by inducing apoptosis in target cells.

An in vitro model for dengue virus infection that exhibits human monocyte infection, multiple cytokine production and dexamethasone immunomodulation

An important cytokine role in dengue fever pathogenesis has been described. These molecules can be associated with haemorrhagic manifestations, coagulation disorders, hypotension and shock, all symptoms implicated in vascular permeability and disease worsening conditions. Several immunological diseases have been treated by cytokine modulation and dexamethasone is utilized clinically to treat pathologies with inflammatory and autoimmune ethiologies. We established an in vitro model with human monocytes infected by dengue virus-2 for evaluating immunomodulatory and antiviral activities of potential pharmaceutical products. Flow cytometry analysis demonstrated significant dengue antigen detection in target cells two days after infection. TNF-alpha, IFN-alpha, IL-6 and IL-10 are produced by in vitro infected monocytes and are significantly detected in cell culture supernatants by multiplex microbead immunoassay. Dexamethasone action was tested for the first time for its modulation in dengue infection, presenting optimistic results in both decreasing cell infection rates and inhibiting TNF-alpha, IFN-alpha and IL-10 production. This model is proposed for novel drug trials yet to be applyed for dengue fever.