scholarly journals Bitter Taste Receptor T2R14 Modulates Gram-Positive Bacterial Internalization and Survival in Gingival Epithelial Cells

2021 ◽  
Vol 22 (18) ◽  
pp. 9920
Author(s):  
Manoj Reddy Medapati ◽  
Anjali Yadav Bhagirath ◽  
Nisha Singh ◽  
Robert J. Schroth ◽  
Rajinder P. Bhullar ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Bitter Taste ◽  
Taste Receptor ◽  
Gram Positive ◽  
Direct Role ◽  
Gram Positive Bacteria ◽  
Inhibition Of Growth ◽  
Gingival Epithelial Cells ◽  
Underlying Mechanisms

Bitter-taste receptors (T2Rs) have emerged as key players in host–pathogen interactions and important modulators of oral innate immunity. Previously, we reported that T2R14 is expressed in gingival epithelial cells (GECs) and interacts with competence stimulating peptides (CSPs) secreted by the cariogenic Streptococcus mutans. The underlying mechanisms of the innate immune responses and physiological effects of T2R14 on Gram-positive bacteria are not well characterized. In this study, we examined the role of T2R14 in internalization and growth inhibitory effects on Gram-positive bacteria, namely Staphylococcus aureus and S. mutans. We utilized CRISPR-Cas9 T2R14 knockdown (KD) GECs as the study model to address these key physiological mechanisms. Our data reveal that the internalization of S. aureus is significantly decreased, while the internalization of S. mutans remains unaffected upon knockdown of T2R14 in GECs. Surprisingly, GECs primed with S. mutans CSP-1 resulted in an inhibition of growth for S. aureus, but not for S. mutans. The GECs infected with S. aureus induced T2R14-dependent human β-defensin-2 (hBD-2) secretion; however, S. mutans–infected GECs did not induce hBD-2 secretion, but induced T2R14 dependent IL-8 secretion. Interestingly, our results show that T2R14 KD affects the cytoskeletal reorganization in GECs, thereby inhibiting S. aureus internalization. Our study highlights the distinct mechanisms and a direct role of T2R14 in influencing physiological responses to Gram-positive bacteria in the oral cavity.

Bacteriophages immunomodulate the response of monocytes

2021 ◽  
pp. 153537022199515
Author(s):  
Lídia Perea ◽  
Lorena Rodríguez-Rubio ◽  
Juan C Nieto ◽  
Carlos Zamora ◽  
Elisabet Cantó ◽  
...  
Keyword(s):  
Cytokine Production ◽  
Statistical Significance ◽  
Control Sample ◽  
Polymyxin B ◽  
Dependent Manner ◽  
Direct Role ◽  
Gram Positive Bacteria ◽  
Hla Dr ◽  
Tnf Α

Bacteriophages are present in fluids from cirrhosis patients. However, their effect on the immune response is unknown. In this work, we explore the role of phages in the phenotype, function, and cytokine production of monocytes. We stimulated healthy monocytes with five different butanol-purified phage suspensions infective for Gram-negative and Gram-positive bacteria. We studied the expression of the monocyte markers involved in lipopolysaccharide recognition (LPS; CD14), antigen presentation (HLA-DR) and co-stimulation (CD86), and the concentration of induced cytokines (TNF-α, IFN-α, and IL-10) by phages. To confirm the direct role of phages without the interference of contaminating soluble LPS in phage suspensions, polymyxin B was added to the cell cultures. Phagocytosis experiments were assessed by flow cytometry using labeled phage suspensions. We observed that butanol-purified phages reduced the surface levels of CD14 and CD86 in monocytes and increased the secreted levels of TNF-α and IL-10 compared with the control sample containing only butanol buffer. All phage suspensions showed downregulation of HLA-DR expression but only Staphylococcus aureus phage contaminated with Escherichia coli reached statistical significance. The addition of polymyxin B did not restore the monocytic response induced by phages, suggesting that the effect was not caused by the presence of LPS. Monocytes were able to phagocyte phages in a dose- and time-dependent manner. To conclude, the phagocytosis of butanol-purified phages altered the phenotype and cytokine production of monocytes suggesting they become tolerogenic.

scholarly journals Role of gram‐positive bacteria in chronic pelvic pain syndrome (CPPS)

The Prostate ◽  
2018 ◽  
Vol 79 (2) ◽  
pp. 160-167 ◽  
Author(s):  
Stephen F. Murphy ◽  
Jonathan F. Anker ◽  
Daniel J. Mazur ◽  
Christel Hall ◽  
Anthony J. Schaeffer ◽  
...  
Keyword(s):  
Pelvic Pain ◽  
Chronic Pelvic Pain ◽  
Chronic Pelvic Pain Syndrome ◽  
Pain Syndrome ◽  
Pelvic Pain Syndrome ◽  
Gram Positive ◽  
Gram Positive Bacteria

scholarly journals Role of Bitter Taste Receptor TAS2R38 In Colorectal Cancer

2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Sonali Choudhury ◽  
Afreen Asif Ali Sayed ◽  
David Standing ◽  
Scott Weir ◽  
Roy Jensen ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Bitter Taste ◽  
Taste Receptor ◽  
Bitter Taste Receptor

scholarly journals The Recombination Genes addAB Are Not Restricted to Gram-Positive Bacteria: Genetic Analysis of the Recombination Initiation Enzymes RecF and AddAB in Rhizobium etli

2004 ◽  
Vol 186 (23) ◽  
pp. 7905-7913 ◽  
Author(s):  
Jacobo Zuñiga-Castillo ◽  
David Romero ◽  
Jaime M. Martínez-Salazar
Keyword(s):  
Recombination Frequency ◽  
Double Strand Breaks ◽  
Additive Effect ◽  
Gram Negative Bacteria ◽  
Rhizobium Etli ◽  
Gram Positive ◽  
Gram Negative ◽  
Strand Breaks ◽  
Gram Positive Bacteria

ABSTRACT Single-strand gaps (SSGs) and double-strand breaks (DSBs) are the major initiation sites for recombination. In bacteria, the SSGs are repaired by RecFOR, while the DSBs are processed by RecBCD in gram-negative bacteria and AddAB in gram-positive bacteria. Unexpectedly, instead of recBCD genes, the addAB genes were found in members of the α-proteobacteria group (gram negative). Taking Rhizobium etli as a model, the role of recF and addAB genes in homologous recombination and repair of damaged DNA was evaluated. Inactivation of either recF or addA provoked strong sensitivity to UV radiation and mitomycin C, while an additive effect was observed in the recF-addA mutant. The DSBs generated by nalidixic acid caused low viability only in the addA mutant. The recombination frequency of large and small plasmids was reduced in the recF mutant (24- and 36-fold, respectively), whereas a slight decrease (threefold) in the addA mutant was observed. Moreover, an additive effect (47- and 90-fold, respectively) was observed in the double mutant, but it was not as dramatic as that in a recA mutant. Interestingly, the frequency of deletion and Campbell-type recombination was slightly affected in either single or double mutants. These results suggest that another pathway exists that allows plasmid and Campbell-type recombination in the absence of recF and addA genes.

scholarly journals Expanding the role of bitter taste receptor in extra oral tissues: TAS2R38 is expressed in human adipocytes

Adipocyte ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Raffaella Cancello ◽  
Giancarlo Micheletto ◽  
Dorela Meta ◽  
Rosalia Lavagno ◽  
Emanuele Bevilacqua ◽  
...  
Keyword(s):  
Bitter Taste ◽  
Taste Receptor ◽  
Human Adipocytes ◽  
Bitter Taste Receptor

scholarly journals Mutations of the Listeria monocytogenes PeptidoglycanN-Deacetylase andO-Acetylase Result in Enhanced Lysozyme Sensitivity, Bacteriolysis, and Hyperinduction of Innate Immune Pathways

2011 ◽  
Vol 79 (9) ◽  
pp. 3596-3606 ◽  
Author(s):  
Chris S. Rae ◽  
Aimee Geissler ◽  
Paul C. Adamson ◽  
Daniel A. Portnoy
Keyword(s):  
Listeria Monocytogenes ◽  
Transcriptional Responses ◽  
Gram Positive ◽  
Content Type ◽  
Growth Defects ◽  
Gram Positive Bacteria ◽  
Host Cell Death

ABSTRACTListeria monocytogenesis a Gram-positive intracellular pathogen that is naturally resistant to lysozyme. Recently, it was shown that peptidoglycan modification by N-deacetylation or O-acetylation confers resistance to lysozyme in various Gram-positive bacteria, includingL. monocytogenes.L. monocytogenespeptidoglycan is deacetylated by the action ofN-acetylglucosamine deacetylase (Pgd) and acetylated byO-acetylmuramic acid transferase (Oat). We characterized Pgd−, Oat−, and double mutants to determine the specific role ofL. monocytogenespeptidoglycan acetylation in conferring lysozyme sensitivity during infection of macrophages and mice. Pgd−and Pgd−Oat−double mutants were attenuated approximately 2 and 3.5 logs, respectively,in vivo. In bone-marrow derived macrophages, the mutants demonstrated intracellular growth defects and increased induction of cytokine transcriptional responses that emanated from a phagosome and the cytosol. Lysozyme-sensitive mutants underwent bacteriolysis in the macrophage cytosol, resulting in AIM2-dependent pyroptosis. Each of thein vitrophenotypes was rescued upon infection of LysM−macrophages. The addition of extracellular lysozyme to LysM−macrophages restored cytokine induction, host cell death, andL. monocytogenesgrowth inhibition. This surprising observation suggests that extracellular lysozyme can access the macrophage cytosol and act on intracellular lysozyme-sensitive bacteria.

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