Apuestas de conservación en las costas de Chiapas y Oaxaca

Las costas de Chiapas y Oaxaca cuentan con una serie de rasgos que las distinguen tanto en lo geográfico y lo biológico como en lo social. Estos estados comparten sistemas de montañas muy cercanos a la costa (la Sierra Madre del Sur y la Sierra Madre de Chiapas), lo que origina planicies muy angostas y amplias lagunas que son sitios de refugio y reproducción para especies de plantas y animales marinos de gran valor económico. Además, en la parte oaxaqueña se encuentra el sistema arrecifal más importante del Pacífico sur mexicano, que es la puerta de entrada a México para la fauna coralina proveniente de Centroamérica

The protective effect of immunoglobulin in murine tuberculosis is dependent on IgG glycosylation

Antibodies have demonstrated having a protective effect in animal models of tuberculosis (TB). These experiments have considered the specificity of antigen recognition and the different isotypes and subclasses as significant contributors of this effect. However, the carbohydrate chain heterogeneity on the Fc region of IgG (Fc-IgG) can play an important role in modulating the immune response. Patients with TB usually have high titers of specific IgG; however, the carbohydrate associated with Fc-IgG usually lacks galactose. To assess the effect of this abnormal IgG in murine pulmonary TB, we evaluated the specificity of recognition to Mycobacterium tuberculosis antigens in vitro and protective effects in vivo comparing human intravenous immunoglobulin (IVIg) and IVIg treated with an endoglycosidase to remove the glycan residues (EndoS-treated IVIg). Our results showed similar antigen recognition. The study of distribution and kinetics of IVIg in serum and bronchial lavage after intraperitoneal (i.p.) administration in mice showed that IVIg circulates for 21days. Finally, the protective effect of intact and EndoS-treated IVIg administered by i.p was studied in a murine model of progressive TB. IVIg treatment caused reduction in pulmonary bacilli loads, larger granulomas, and less pneumonia, while animals treated with EndoS-treated IVIg were not protected compared with control animals. Thus, IVIg has a protective activity in experimental pulmonary TB, and this effect requires intact Fc oligosaccharides. This work compares conventional fully glycosylated and deglycosylated IVIg determining their mycobacterial antigen recognition by two dimensional Western-blotting, specific mycobacterial antigen recognition by ELISA, kinetics of distribution after intraperitoneal administration, and protective efficiency by evaluating pulmonary bacilli loads and tissue damage after i.p. administration during early infection in a model of progressive pulmonary tuberculosis. The results add to the growing body of information that antibodies have a protective effect at least in animal models of tuberculosis

Diverging biological roles among human monocyte subsets in the context of tuberculosis infection

Circulating monocytes (Mo) play an essential role in the host immune response to chronic infections. We previously demonstrated that CD16pos Mo were expanded in TB (tuberculosis) patients, correlated with disease severity and were refractory to dendritic cell differentiation. In the present study, we investigated whether human Mo subsets (CD16neg and CD16pos) differed in their ability to influence the early inflammatory response against Mycobacterium tuberculosis. We first evaluated the capacity of the Mo subsets to migrate and engage a microbicidal response in vitro. Accordingly, CD16neg Mo were more prone to migrate in response to different mycobacteria-derived gradients, were more resistant to M. tuberculosis intracellular growth and produced higher reactive oxygen species than their CD16pos counterpart. To assess further the functional dichotomy among the human Mo subsets, we carried out an in vivo analysis by adapting a hybrid mouse model (SCID/Beige, where SCID is severe combined immunodeficient) to transfer each Mo subset, track their migratory fate during M. tuberculosis infection, and determine their impact on the host immune response. In M. tuberculosis-infected mice, the adoptively transferred CD16neg Mo displayed a higher lung migration index, induced a stronger pulmonary infiltration of murine leucocytes expressing pro- and anti-inflammatory cytokines, and significantly decreased the bacterial burden, in comparison with CD16pos Mo. Collectively, our results indicate that human Mo subsets display divergent biological roles in the context of M. tuberculosis infection, a scenario in which CD16neg Mo may contribute to the anti-mycobacterial immune response, whereas CD16pos Mo might promote microbial resilience, shedding light on a key aspect of the physiopathology of TB disease.Fil: Balboa, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Barrios Payan, Jorge. Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán"; MéxicoFil: González Domínguez, Erika. Instituto Politécnico Nacional; MéxicoFil: Lastrucci, Claire. Institut de Pharmacologie et de Biologie Structurale; FranciaFil: Lugo Villarino, Geanncarlo. Institut de Pharmacologie et de Biologie Structurale; FranciaFil: Mata Espinoza, Dulce. Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán"; MéxicoFil: Schierloh, Luis Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Kviatcovsky, Denise. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Neyrolles, Olivier. Institut de Pharmacologie et de Biologie Structurale; FranciaFil: Maridonneau Parini, Isabelle. Institut de Pharmacologie et de Biologie Structurale; FranciaFil: Sánchez Torres, Carmen. Instituto Politécnico Nacional; MéxicoFil: Sasiain, María del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Hernández Pando, Rogelio. Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán"; Méxic

Protective Effect of a Lipid-Based Preparation from Mycobacterium smegmatis in a Murine Model of Progressive Pulmonary Tuberculosis

A more effective vaccine against tuberculosis (TB) is urgently needed. Based on its high genetic homology with Mycobacterium tuberculosis (Mtb), the nonpathogenic mycobacteria, Mycobacterium smegmatis (Ms), could be an attractive source of potential antigens to be included in such a vaccine. We evaluated the capability of lipid-based preparations obtained from Ms to provide a protective response in Balb/c mice after challenge with Mtb H37Rv strain. The intratracheal model of progressive pulmonary TB was used to assess the level of protection in terms of bacterial load as well as the pathological changes in the lungs of immunized Balb/c mice following challenge with Mtb. Mice immunized with the lipid-based preparation from Ms either adjuvanted with Alum (LMs-AL) or nonadjuvanted (LMs) showed significant reductions in bacterial load (P<0.01) compared to the negative control group (animals immunized with phosphate buffered saline (PBS)). Both lipid formulations showed the same level of protection as Bacille Calmette and Guerin (BCG). Regarding the pathologic changes in the lungs, mice immunized with both lipid formulations showed less pneumonic area when compared with the PBS group (P<0.01) and showed similar results compared with the BCG group. These findings suggest the potential of LMs as a promising vaccine candidate against TB