Copper (Cu) is essential for many biological processes, but toxic when present in excessive amounts. In this study, we provide evidence that Cu plays a crucial role controlling tuberculosis. A Mycobacterium tuberculosis ( Mtb ) mutant lacking the outer membrane channel protein Rv1698 accumulated 100-fold more and was susceptible to toxicity than WT . Similar phenotypes were observed M. smegmatis homolog Ms3747, demonstrating these mycobacterial copper transport proteins B (MctB) are...

ABSTRACT Following integration, HIV-1 in most cases produces active infection events; however, some rare instances, latent events are established. The latter have major clinical implications, as allows the virus to persist despite antiretroviral therapy. Both cellular factors and viral elements that potentially determine whether establishes or remain largely elusive. We detail here contribution of different long terminal repeat (LTR) sequences for establishment infection. Using a panel...

ABSTRACT Tuberculosis is a severe disease affecting millions worldwide. Unfortunately, treatment strategies are hampered both by the prohibitively long regimen and rise of drug-resistant strains. Significant effort has been expended in search for new treatments, but few options have successfully emerged, modalities desperately needed. Recently, there growing interest synergistic antibacterial effects copper ions (Cu II/I ) combination with certain small molecular compounds, we previously...

Copper (Cu) ions are likely the most important immunological metal-related toxin utilized in controlling bacterial infections. Impairment of Cu resistance reduces viability within host. Thus, pharmacological enhancement Cu-mediated antibacterial toxicity may lead to novel strategies drug discovery and development. Screening for toxicity-enhancing molecules identified 8-hydroxyquinoline (8HQ) be a potent Cu-dependent bactericidal inhibitor Mycobacterium tuberculosis The MIC 8HQ presence was...

Summary Mycobacteria have a unique outer membrane (OM) that is thicker than any other known biological membrane. Nutrients cross this permeability barrier by diffusion through porins. MspA the major porin of Mycobacterium smegmatis . In study we showed three paralogues MspA, namely MspB, MspC and MspD are also However, only mspA mspC genes were expressed in wild‐type strain. None single deletion mutants displayed significant OM defect except for mutant. Deletion gene caused activation...

Macrophages take advantage of the antibacterial properties copper ions in killing bacterial intruders. However, despite importance for innate immune functions, coordinated efforts to exploit therapeutic interventions against infections are not yet place. Here we report a novel high-throughput screening platform specifically developed discovery and characterization compounds with copper-dependent toward methicillin-resistant Staphylococcus aureus (MRSA). We detail how one identified...

We and others recently identified copper resistance as important for virulence of Mycobacterium tuberculosis. Here, we introduce a high-throughput screening assay agents that induce hypersensitivity phenotype in M. tuberculosis demonstrate such copper-boosting compounds are effective against replicating nonreplicating strains.

Mycobacteria contain an outer membrane composed of mycolic acids and a large variety other lipids. Its protective function is essential virulence factor Mycobacterium tuberculosis. Only OmpA, which has numerous homologs in Gram-negative bacteria, known to form channels the M. tuberculosis so far. Rv1698 was predicted be protein unknown function. Expression rv1698 restored sensitivity ampicillin chloramphenicol smegmatis mutant lacking main porin MspA. Uptake experiments showed that partially...

The SecA2 protein is part of a specialized export system mycobacteria. We set out to identify proteins exported the bacterial cell envelope by mycobacterial system. By comparing profiles wall and membrane fractions from wild-type DeltasecA2 mutant Mycobacterium smegmatis, we identified Msmeg1712 Msmeg1704 as SecA2-dependent proteins. These are first endogenous M. smegmatis dependent on for export. Both homologous periplasmic sugar-binding other bacteria, both contain functional...

Abstract The ability to suppress host macrophage apoptosis is essential for M. tuberculosis ( Mtb ) replicate intracellularly while protecting it from antibiotic treatment. We recently described that infection upregulated expression of the phosphatase PPM1A, which impairs antibacterial response macrophages. Here we establish PPM1A as a checkpoint target used by apoptosis. Overproduction suppressed Mtb- infected macrophages mechanism involves inactivation c-Jun N-terminal kinase (JNK)....

Copper resistance mechanisms are crucial for many pathogenic bacteria, including Mycobacterium tuberculosis, during infection because the innate immune system utilizes copper ions to kill bacterial intruders. Despite several studies detailing responses of mycobacteria copper, pathways by which cross mycobacterial cell envelope unknown. Deletion porin genes in smegmatis leads a severe growth defect on trace medium but simultaneously increases tolerance at elevated concentrations, indicating...

Despite the clinical relevance of latent HIV-1 infection as a block to eradication, molecular biology latency remains incompletely understood. We recently demonstrated presence gatekeeper kinase function that controls infection. Using array analysis, we here expand on this finding and demonstrate activity profile latently HIV-1-infected T cells is altered relative uninfected cells. A ranking kinases generated from these kinome data predicted PIM-1 key switch involved in control. genetic...

Abstract One potential source of new antibacterials is through probing existing chemical libraries for copper-dependent inhibitors (CDIs), i.e., molecules with antibiotic activity only in the presence copper. Recently, our group demonstrated that previously unknown staphylococcal CDIs were frequently present a small pilot screen. Here, we report outcome larger industrial anti-staphylococcal screen consisting 40 771 compounds assayed parallel, both standard and copper-supplemented media....

Phosphorus is an essential nutrient, but how phosphates cross the mycobacterial cell wall unknown. Phosphatase activity in whole cells of Mycobacterium smegmatis was significantly lower than that lysed cells, indicating access to substrate restricted. The loss outer membrane (OM) porin MspA also reduced phosphatase compared cells. A similar result obtained for M. overexpressed endogenous alkaline phosphatase, PhoA not a surface protein, contrary previous report. uptake phosphate by mutant...

ABSTRACT Despite its clinical importance, the molecular biology of HIV-1 latency control is at best partially understood, and literature remains conflicting. The most recent description that latent integrated into actively expressed host genes has further confounded situation. This lack understanding complicates our efforts to identify therapeutic compounds or strategies could reactivate infection in patients, a prerequisite for eradication infection. Currently, many development operate...

// Jim Sun 1 , Kaitlyn Schaaf 2 Alexandra Duverger Frank Wolschendorf Alexander Speer 1,3 Frederic Wagner Michael Niederweis and Olaf Kutsch Department of Microbiology, University Alabama at Birmingham, Alabama, USA Medicine, 3 Medical Microbiology Infection Control, VU Center, Amsterdam, Netherlands Correspondence to: Kutsch, email: Sun, Keywords : HIV-1, PPM1A, macrophages, Mycobacterium tuberculosis, persistent infection, Immunology Section, Immune response, Immunity Received January 12,...

ABSTRACT The extreme stability of the latent HIV-1 reservoir in CD4 + memory T cell population prevents viral eradication with current antiretroviral therapy. It has been demonstrated that homeostatic proliferation and clonal expansion latently infected cells due to integration into specific genes contribute this extraordinary stability. Nevertheless, given constant exposure antigen or bystander activation, seems remarkable, unless it is assumed resides exclusively recognize rare antigens....

Inorganic polyphosphate (polyP) is a biological polymer found in cells from all domains of life, and required for virulence stress response many bacteria. There are variety methods quantifying polyP materials, which either labor-intensive or insensitive, limiting their usefulness. We present here streamlined method quantification bacteria, using silica membrane column extraction optimized rapid processing multiple samples, digestion with the polyP-specific exopolyphosphatase ScPPX, detection...

In the last 40 years, only a single new antituberculosis drug was FDA approved. New tools that improve development process will be essential to accelerate of next-generation drugs. The seems hampered by inefficient transition initially promising hits candidate compounds are effective in vivo. this study, we introduce an inexpensive, rapid, and BSL-2 compatible infection model using macrophage-passaged Mycobacterium tuberculosis (Mtb) forms densely packed Mtb/macrophage aggregate structures...

ABSTRACT Current antiretroviral therapy (ART) efficiently controls HIV-1 replication but fails to eradicate the virus. Even after years of successful ART, can conceal itself in a latent state long-lived CD4 + memory T cells. From this reservoir, rebounds during treatment interruptions. Attempts therapeutically viral reservoir have yielded disappointing results. A major problem with previously utilized activating agents is that at concentrations required for efficient reactivation, these...

Reactivation of latent HIV-1 infection is considered our best therapeutic means to eliminate the reservoir. Past attempts systemically trigger reactivation using single drugs were unsuccessful. We thus sought identify drug combinations consisting one component that would lower threshold and a synergistic activator. With aclacinomycin dactinomycin, we initially identified two FDA-approved primed in T cell lines primary cells for facilitated complete at population level. This effect was...