Activity of Semi-Synthetic Mulinanes against MDR, Pre-XDR, and XDR Strains of Mycobacterium tuberculosis

Tuberculosis causes more than 1.2 million deaths each year. Worldwide, it is the first cause of death by a single infectious agent. The emergence of drug-resistant strains has limited pharmacological treatment of the disease and today, new drugs are urgently needed. Semi-synthetic mulinanes have previously shown important activity against multidrug-resistant (MDR) Mycobacterium tuberculosis. In this investigation, a new set of semi-synthetic mulinanes were synthetized, characterized, and evaluated for their in vitro activity against three drug-resistant clinical isolates of M. tuberculosis: MDR, pre-extensively Drug-Resistant (pre-XDR), and extensively Drug-Resistant (XDR), and against the drug-susceptible laboratory reference strain H37Rv. Derivative 1a showed the best anti-TB activity (minimum inhibitory concentration [MIC] = 5.4 µM) against the susceptible strain and was twice as potent (MIC = 2.7 µM) on the MDR, pre-XDR, and XDR strains and also possessed a bactericidal effect. Derivative 1a was also tested for its anti-TB activity in mice infected with the MDR strain. In this case, 1a produced a significant reduction of pulmonary bacilli loads, six times lower than the control, when tested at 0.2536 mg/Kg. In addition, 1a demonstrated an adjuvant effect by shortening second-line chemotherapy. Finally, the selectivity index of >15.64 shown by 1a when tested on Vero cells makes this derivative an important candidate for future studies in the development of novel antitubercular agents

Trypanosoma cruzi High Mobility Group B (TcHMGB) can act as an inflammatory mediator on mammalian cells

When an infection occurs, the innate immune cells recognize Pathogen Associated Molec ular Patterns (PAMPs) through their Pattern Recognition Receptors. This triggers an inflammatory response intended to kill the foreign microbe. But inflammation can also be triggered by the recognition of endogenous molecules called “Danger (or Damage) Asso ciated Molecular Patterns” (DAMPs) that are released by damaged or necrotic cells to “ring the alarm” of the immune system that repair is needed, so some of them are also known as “alarmins”. High Mobility group box 1 protein (HMGB1) is a prototypical alar min molecule released by injured cells and it is also actively secreted by cells of the innate immune system in response to invasion as well as to sterile damage. Trypanosoma cruzi, the causal agent of Chagas Disease, has its own HMGB protein that we called TcHMGB. Using in vitro and in vivo experimental systems, we demonstrated for the first time that TcHMGB is able to mediate inflammation on mammalian cells, inducing the expression of both pro-inflammatory and anti-inflammatory cytokines. Our results suggest that the parasite´s protein could have a role in the immune response and the pathogenesis of Cha gas disease, probably overlapping to some extent with the host cell DAMP molecules´ functions.Para citar este articulo: Cribb P, Perdomo V, Alonso VL, Manarin R, Barrios-Paya´n J, Marquina-Castillo B, et al. (2017) Trypanosoma cruzi High Mobility Group B (TcHMGB) can act as an inflammatory mediator on mammalian cells. PLoS Negl Trop Dis 11(2): e0005350. doi:10.1371/journal.pntd.0005350Fil: Cribb, Pamela. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario (IBR -CONICET); Argentina.Fil: Cribb, Pamela. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina.Fil: Perdomo, Virginia Gabriela. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario (IBR -CONICET); Argentina.Fil: Perdomo, Virginia Gabriela. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina.Fil: Alonso, Victoria Lucía. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina.Fil: Manarin, Romina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina.Fil: Barrios-Payán, Jorge. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán. Sección de Patología Experimental; México.Fil: Marquina-Castillo, Brenda. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán. Sección de Patología Experimental; México.Fil: Tavernelli, Luis. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario (IBR -CONICET); Argentina.Fil: Hernández-Pando, Rogelio. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán. Sección de Patología Experimental; México