Genetic background affects the expansion of macrophage subsets in the lungs of Mycobacterium tuberculosis-infected hosts.

M1 macrophages are more effective in the induction of the inflammatory response and clearance of Mycobacterium tuberculosis than M2 macrophages. Infected C57BL/6 mice generate a stronger cellular immune response compared with BALB/c mice. We hypothesized that infected C57BL/6 mice would exhibit a higher frequency and function of M1 macrophages than infected BALB/c mice. Our findings show a higher ratio of macrophages to M2 macrophages in the lungs of chronically infected C57BL/6 mice compared with BALB/c mice. However, there was no difference in the functional ability of M1 and M2 macrophages for the two strains in vitro. In vivo, a deleterious role for M2 macrophages was confirmed by M2 cell transfer, which rendered the infected C57BL/6, but not the BALB/c mice, more susceptible and resulted in mild lung inflammation compared with C57BL/6 mice that did not undergo cell transfer. M1 cell transfer induced a higher inflammatory response, although not protective, in infected BALB/c mice compared with their counterparts that did not undergo cell transfer. These findings demonstrate that an inflammation mediated by M1 macrophages may not induce bacterial tolerance because protection depends on the host genetic background, which drives the magnitude of the inflammatory response against M. tuberculosis in the pulmonary microenvironment. The contribution of our findings is that although M1 macrophage is an effector leucocyte with microbicidal machinery, its dominant role depends on the balance of M1 and M2 subsets, which is driven by the host genetic background.

Association between Schistosomiasis mansoni and hepatitis C: systematic review / Associacao entre esquistossomose mansonica e hepatite C: revisao sistematica / Asociacion entre esquistosomiasis mansoni y hepatitis C: revision sistematica

OBJECTIVE: To perform a systematic review of the prevalence of the HCV/ S. mansoni co-infection and associated factors in Schistosoma mansoni -infected populations. METHODS: The bibliographic search was carried out using the Medline, Lilacs, SciELO, Cochrane Library and Ibecs databases. The criteria for the studies' selection and the extraction data were based on systematic review methods. Forty five studies were found, with nine being excluded in a first screening. Thirteen articles were used for data extraction. RESULTS: The HCV infection rates in schistosomiasis populations range from 1% in Ethiopia to 50% in Egypt. Several studies had poorly defined methodologies, even in areas characterized by an association between hepatitis C and schistosomiasis, such as Brazil and Egypt, which meant conclusions were inconsistent. HCV infection rates in schistosomotic populations were heterogeneous and risk factors for acquiring the virus varied widely. CONCLUSIONS: Despite the limitations, this review may help to identify regions with higher rates of hepatitis C and schistosomiasis association. However, more studies are necessary for the development of public health policies on prevention and control of both diseases. .

OBJETIVO: Realizar revisão sistemática sobre a prevalência da confecção do vírus da hepatite C e Schistosoma mansoni e os fatores de risco associados a indivíduos com esquistossomose. MÉTODOS: Revisão realizada nas bases de dados Medline, Lilacs, SciELO, Biblioteca Cochrane e Ibecs. Os critérios de seleção e a obtenção dos dados foram baseados em métodos de revisão sistemática. Foram encontradas 45 referências relevantes, das quais nove foram excluídas na primeira triagem, 14 na leitura dos resumos e nove na leitura completa. Treze artigos foram selecionados para análise. RESULTADOS: A prevalência da associação entre vírus da hepatite C e Schistosoma mansoni variou de 1% na Etiópia a 50% no Egito. Alguns estudos apresentam metodologias pouco definidas, mesmo em áreas caracterizadas pela associação entre vírus da hepatite C e S. mansoni , como Brasil e Egito, o que não permitiu conclusões consistentes. As taxas de infecção pelo VHC em populações esquistossomáticas foram heterogêneas e os fatores de risco para adquirir o vírus foram variáveis. CONCLUSÕES: Apesar das limitações, esta análise pode ajudar a identificar regiões com maiores taxas dessa associação. Outros estudos serão necessários para o desenvolvimento de políticas públicas de prevenção e controle dessas doenças. .

OBJETIVO: Realizar revisión sistemática sobre la prevalencia de la co-infección del virus de la hepatitis C y Schistosoma mansoni y los factores de riesgo asociados a individuos con esquistosomosis. MÉTODOS: Revisión realizada en las bases de datos MEDLINE, LILACS, SciELO, Biblioteca Cochrane e IBECS. Los criterios de selección y la obtención de los datos fueron basados en métodos de revisión sistemática. RESULTADOS: Fueron encontradas 45 referencias relevantes, de las cuales, nueve fueron excluidas en la primera selección, 14 en la lectura de los resúmenes y nueve en la lectura completa. Trece artículos fueron seleccionados para análisis. La prevalencia de la asociación entre virus de la hepatitis C y Schistosoma mansoni varió de 1% en Etiopia, a 50% en Egipto. Algunos estudios presentan metodologías poco definidas, inclusive en áreas caracterizadas por la asociación entre el virus de la hepatitis C y S. mansoni, como Brasil y Egipto, lo que no permitió conclusiones consistentes. Los cocientes de infección por el VHC en poblaciones esquistosómicas fueron heterogéneos y los factores de riesgo para adquirir el virus fueron variables. CONCLUSIONES: A pesar de las limitaciones, este análisis pudo ayudar a identificar regiones con mayores cocientes de esa asociación. Otros estudios serán necesarios para el desarrollo de políticas públicas de prevención y control de estas enfermedades. .