المؤلفون: Bigi, María M, Forrellad, Marina A, García, Julia S, Blanco, Federico C, Vázquez, Cristina L, Bigi, Fabiana

المصدر: Future Microbiology; December 2023, Vol. 18 Issue: 18 p1381-1398, 18p

مستخلص: Almost 3% of the proteins of Mycobacterium tuberculosis(M. tuberculosis), the main causative agent of human tuberculosis, are lipoproteins. These lipoproteins are characteristic of the mycobacterial cell envelope and participate in many mechanisms involved in the pathogenesis of M. tuberculosis. In this review, the authors provide an updated analysis of M. tuberculosislipoproteins and categorize them according to their demonstrated or predicted functions, including transport of compounds to and from the cytoplasm, biosynthesis of the mycobacterial cell envelope, defense and resistance mechanisms, enzymatic activities and signaling pathways. In addition, this updated analysis revealed that at least 40% of M. tuberculosislipoproteins are glycosylated.

المؤلفون: Forrellad, Marina A., Vázquez, Cristina L., Blanco, Federico C., Klepp, Laura I., García, Elizabeth A., Rocha, Rosana V., Luciana, Villafañe, Bigi, María M., Gutierrez, Maximiliano G., Bigi, Fabiana

المصدر: Virulence; January 2019, Vol. 10 Issue: 1 p1026-1033, 8p

مستخلص: ABSTRACTIn this study, we characterized the role of Rv2617c in the virulence of Mycobacterium tuberculosis. Rv2617c is a protein of unknown function unique to M. tuberculosiscomplex (MTC) and Mycobacterium leprae. In vitro, this protein interacts with the virulence factor P36 (also named Erp) and KdpF, a protein linked to nitrosative stress. Here, we showed that knockout of the Rv2617cgene in M. tuberculosisCDC1551 reduced the replication of the pathogen in a mouse model of infection and favored the trafficking of mycobacteria to phagolysosomes. We also demonstrated that Rv2617c and P36 are required for resistance to in vitrohydrogen peroxide treatment in M. tuberculosisand Mycobacterium bovis, respectively. These findings indicate Rv2617c and P36 act in concert to prevent bacterial damage upon oxidative stress.

المؤلفون: Romano, Patricia S., Arboit, María A., Vázquez, Cristina L., Colombo, María Isabel

المصدر: Autophagy; January 2009, Vol. 5 Issue: 1 p6-18, 13p

مستخلص: The etiologic agent of Chagas disease, Trypanosoma cruzi, infects mammalian cells activating a signal transduction cascade that leads to the formation of its parasitophorous vacuole. Previous works have demonstrated the crucial role of lysosomes in the establishment of T. cruziinfection. In this work we have studied the possible relationship between this parasite and the host cell autophagy. We show, for the first time, that the vacuole containing T. cruzi(TcPV) is decorated by the host cell autophagic protein LC3. Furthermore, live cell imaging experiments indicate that autolysosomes are recruited to parasite entry sites. Interestingly, starvation or pharmacological induction of autophagy before infection significantly increased the number of infected cells whereas inhibitors of this pathway reduced the invasion. In addition, the absence of Atg5 or the reduced expression of Beclin1, two proteins required at the initial steps of autophagosome formation, limited parasite entry and reduced the association between TcPV and the classical lysosomal marker Lamp-1. These results indicate that mammalian autophagy is a key process that favors the colonization of T. cruziin the host cell.