A T4SS Effector Targets Host Cell Alpha-Enolase Contributing to Brucella abortus Intracellular Lifestyle

Marchesini, María Inés; Seijo, Susana María Morrone; Guaimas, Francisco; Comerci, Diego J.

doi:10.3389/fcimb.2016.00153

Cited by 23 publications

(16 citation statements)

References 64 publications

(82 reference statements)

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“…The microscopic examination was performed on the basis of studies by Chou et al and Marchesini et al [61,62] with modifications. The preparations were examined under the Olympus BX51 microscope (Olympus Optical, Tokyo, Japan) using a ×10 lens with a numerical aperture of 0.3.…”

Section: Methodsmentioning

confidence: 99%

In Vitro Activity of 3-Bromopyruvate, an Anticancer Compound, Against Antibiotic-Susceptible and Antibiotic-Resistant Helicobacter pylori Strains

Krzyżek

Franiczek

Krzyżanowska

et al. 2019

Cancers

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Helicobacter pylori (H. pylori) is a bacterium capable of inducing chronic active gastritis, which in some people, develops into gastric cancers. One of the substances that may be useful in the eradication of this microorganism is 3-Bromopyruvate (3-BP), an anticancer compound with antimicrobial properties. The aim of this article was to determine the activity of 3-BP against antibiotic-susceptible and antibiotic-resistant H. pylori strains. The antimicrobial activity was determined using a disk-diffusion method, broth microdilution method, time-killing assay, and checkerboard assay. The research was extended by observations using light, fluorescence, and scanning electron microscopy. The growth inhibition zones produced by 2 mg/disk with 3-BP counted for 16–32.5 mm. The minimal inhibitory concentrations (MICs) ranged from 32 to 128 μg/mL, while the minimal bactericidal concentrations (MBCs) for all tested strains had values of 128 μg/mL. The time-killing assay demonstrated the concentration-dependent and time-dependent bactericidal activity of 3-BP. The decrease in culturability below the detection threshold (<100 CFU/mL) was demonstrated after 6 h, 4 h, and 2 h of incubation for MIC, 2× MIC, and 4× MIC, respectively. Bacteria treated with 3-BP had a several times reduced mean green/red fluorescence ratio compared to the control samples, suggesting bactericidal activity, which was independent from an induction of coccoid forms. The checkerboard assay showed the existence of a synergistic/additive interaction of 3-BP with amoxicillin, tetracycline, and clarithromycin. Based on the presented results, it is suggested that 3-BP may be an interesting anti-H. pylori compound.

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Section: Methodsmentioning

confidence: 99%

In Vitro Activity of 3-Bromopyruvate, an Anticancer Compound, Against Antibiotic-Susceptible and Antibiotic-Resistant Helicobacter pylori Strains

Krzyżek

Franiczek

Krzyżanowska

et al. 2019

Cancers

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“…Interestingly, the first enzyme to use NAD + in glycolysis, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) has been shown to be recruited to the membrane of Brucella-containing vacuoles playing an essential role in intracellular replication [38]. Previous studies have also reported the role of the specific T4SS effector BPE123 in targeting the host enolase, another enzyme of the glycolysis pathway, which was also shown to be essential for Brucella intracellular multiplication in human cultured epithelial cells [39].…”

Section: Plos Pathogensmentioning

confidence: 99%

The TIR-domain containing effectors BtpA and BtpB from Brucella abortus impact NAD metabolism

et al. 2020

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Brucella species are facultative intracellular Gram-negative bacteria relevant to animal and human health. Their ability to establish an intracellular niche and subvert host cell pathways to their advantage depends on the delivery of bacterial effector proteins through a type IV secretion system. Brucella Toll/Interleukin-1 Receptor (TIR)-domain-containing proteins BtpA (also known as TcpB) and BtpB are among such effectors. Although divergent in primary sequence, they interfere with Toll-like receptor (TLR) signaling to inhibit the innate immune responses. However, the molecular mechanisms implicated still remain unclear. To gain insight into the functions of BtpA and BtpB, we expressed them in the budding yeast Saccharomyces cerevisiae as a eukaryotic cell model. We found that both effectors were cytotoxic and that their respective TIR domains were necessary and sufficient for yeast growth inhibition. Growth arrest was concomitant with actin depolymerization, endocytic block and a general decrease in kinase activity in the cell, suggesting a failure in energetic metabolism. Indeed, levels of ATP and NAD + were low in yeast cells expressing BtpA and BtpB TIR domains, consistent with the recently described enzymatic activity of some TIR domains as NAD + hydrolases. In human epithelial cells, both BtpA and BtpB expression reduced intracellular total NAD levels. In infected cells, both BtpA and BtpB contributed to reduction of total NAD, indicating that their NAD + hydrolase functions are active intracellularly during infection. Overall, combining the yeast model together with mammalian cells and infection studies our results show that BtpA and BtpB modulate energy metabolism in host cells through NAD + hydrolysis, assigning a novel role for these TIR domain-containing effectors in Brucella pathogenesis.

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“…Interestingly, the first enzyme to use NAD + in glycolysis, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) has been shown to be recruited to the membrane of Brucella- containing vacuoles playing and essential role in intracellular replication [36]. Previous studies have also reported the role of the specific T4SS effector BPE123 in targeting the host enolase, another enzyme of the glycolysis pathway, which was also shown to be essential for Brucella intracellular multiplication in human cultured epithelial cells [37]. Host metabolism during Brucella infection has only recently started to be unravelled.…”

Section: Discussionmentioning

confidence: 99%

The TIR-domain containing effectors BtpA and BtpB fromBrucella abortusblock energy metabolism

Coronas-Serna

Louche

Rodríguez-Escudero

et al. 2019

Preprint

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27Brucella species are facultative intracellular Gram-negative bacteria relevant to animal 28 and human health. Their ability to establish an intracellular niche and subvert host cell 29 pathways to their advantage depends on the delivery of bacterial effector proteins 30 through a type IV secretion system. Brucella Toll/Interleukin-1 Receptor (TIR)-domain-31 containing proteins BtpA (also known as TcpB) and BtpB are among such effectors. 32Although divergent in primary sequence, they interfere with Toll-like receptor (TLR) 33 signaling to inhibit the innate immune responses. However, the molecular mechanisms 34 implicated still remain unclear. To gain insight into the functions of BtpA and BtpB, we 35 expressed them in the budding yeast Saccharomyces cerevisiae as a eukaryotic cell 36 model. We found that both effectors were cytotoxic and that their respective TIR 37 domains were necessary and sufficient for yeast growth inhibition. Growth arrest was 38 concomitant with actin depolymerization, endocytic block and a general decrease in 39 kinase activity in the cell, suggesting a failure in energetic metabolism. Indeed, levels of 40 ATP and NAD + were low in yeast cells expressing BtpA and BtpB TIR domains, 41 consistent with the recently described enzymatic activity of some TIR domains as 42 NAD + hydrolases. In human epithelial cells, both BtpA and BtpB expression reduced 43 intracellular total NAD levels. In infected cells, both BtpA and BtpB contributed to 44 reduction of total NAD, indicating that their NAD + hydrolase functions are active 45 intracellularly during infection. Overall, combining the yeast model together with 46 mammalian cells and infection studies our results show that BtpA and BtpB modulate 47 AUTHOR SUMMARY 51Brucella is a genus of zoonotic bacteria that cause severe disease in a variety of 52 mammals, ranging from farm animals (as bovines, swine and ovine) to marine 53 mammals. Transmission to humans, often by ingestion of non-treated dairy products, 54 leads to serious systemic infection. Brucella abortus invades host cells and replicates 55intracellularly. Such behavior relies on the injection of bacterial proteins into the host 56 cytoplasm via specialized secretion systems. Our work focuses on the study of two of 57 these factors, BtpA and BtpB, previously described to contain Toll/Interleukin-1 58Receptor (TIR)-domains that modulate innate immunity. We use here two biological 59 models: the yeast Saccharomyces cerevisiae and human cell lines. We found that the 60 TIR domains of both Brucella proteins were necessary and sufficient to collapse energy 61 metabolism in yeast by depleting ATP and NAD + . This result was translatable to higher 62 cells and consistent with the recently described NADase activity of some TIR domains 63 both in mammalian and bacterial proteins. Importantly, we demonstrate that Brucella 64 down-regulates total NAD levels in host cells by using both BtpA and BtpB effectors. 65Our results show that NAD + is targeted by Brucella during infection, which may 66 cons...

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A T4SS Effector Targets Host Cell Alpha-Enolase Contributing to Brucella abortus Intracellular Lifestyle

Cited by 23 publications

References 64 publications

In Vitro Activity of 3-Bromopyruvate, an Anticancer Compound, Against Antibiotic-Susceptible and Antibiotic-Resistant Helicobacter pylori Strains

In Vitro Activity of 3-Bromopyruvate, an Anticancer Compound, Against Antibiotic-Susceptible and Antibiotic-Resistant Helicobacter pylori Strains

The TIR-domain containing effectors BtpA and BtpB from Brucella abortus impact NAD metabolism

The TIR-domain containing effectors BtpA and BtpB fromBrucella abortusblock energy metabolism

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