scholarly journals The Role of Proteases in the Virulence of Plant Pathogenic Bacteria

2019 ◽  
Vol 20 (3) ◽  
pp. 672 ◽  
Author(s):  
Donata Figaj ◽  
Patrycja Ambroziak ◽  
Tomasz Przepiora ◽  
Joanna Skorko-Glonek
Keyword(s):  
Control Systems ◽  
Host Defense ◽  
Defense Mechanisms ◽  
Pathogenic Bacteria ◽  
Protein Quality ◽  
External Environment ◽  
Bacterial Cells ◽  
Plant Pathogenic Bacteria ◽  
Adverse Environmental Conditions

A pathogenic lifestyle is inextricably linked with the constant necessity of facing various challenges exerted by the external environment (both within and outside the host). To successfully colonize the host and establish infection, pathogens have evolved sophisticated systems to combat the host defense mechanisms and also to be able to withstand adverse environmental conditions. Proteases, as crucial components of these systems, are involved in a variety of processes associated with infection. In phytopathogenic bacteria, they play important regulatory roles and modulate the expression and functioning of various virulence factors. Secretory proteases directly help avoid recognition by the plant immune systems, and contribute to the deactivation of the defense response pathways. Finally, proteases are important components of protein quality control systems, and thus enable maintaining homeostasis in stressed bacterial cells. In this review, we discuss the known protease functions and protease-regulated signaling processes associated with virulence of plant pathogenic bacteria.

scholarly journals Role of Intestinal Mucins in Innate Host Defense Mechanisms against Pathogens

2008 ◽  
Vol 1 (2) ◽  
pp. 123-135 ◽  
Author(s):  
Poonam Dharmani ◽  
Vikas Srivastava ◽  
Vanessa Kissoon-Singh ◽  
Kris Chadee
Keyword(s):  
Host Defense ◽  
Defense Mechanisms ◽  
Intestinal Mucins

Sex-dependent liver colonization of human melanoma in SCID mice—role of host defense mechanisms

2012 ◽  
Vol 30 (4) ◽  
pp. 497-506 ◽  
Author(s):  
Judit Dobos ◽  
Anita Mohos ◽  
József Tóvári ◽  
Erzsébet Rásó ◽  
Tamás Lőrincz ◽  
...  
Keyword(s):  
Host Defense ◽  
Defense Mechanisms ◽  
Human Melanoma ◽  
Scid Mice

The Role of Prophage in Plant-Pathogenic Bacteria

2013 ◽  
Vol 51 (1) ◽  
pp. 429-451 ◽  
Author(s):  
Alessandro M. Varani ◽  
Claudia Barros Monteiro-Vitorello ◽  
Helder I. Nakaya ◽  
Marie-Anne Van Sluys
Keyword(s):  
Pathogenic Bacteria ◽  
Plant Pathogenic Bacteria

Enzyme-linked immunosorbent assay on nitrocellulose membranes (dot–ELISA) in the serodiagnosis of plant pathogenic bacteria

1987 ◽  
Vol 33 (2) ◽  
pp. 98-103 ◽  
Author(s):  
G. Lazarovits ◽  
D. Zutra ◽  
M. Bar-Joseph
Keyword(s):  
Immunosorbent Assay ◽  
Xanthomonas Campestris ◽  
Pathogenic Bacteria ◽  
Protein A ◽  
Live Cells ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bacterial Cells ◽  
Plant Pathogenic Bacteria ◽  
Pepper Leaves ◽  
Dot Elisa

The usefulness of enzyme-linked immunosorbent assay on nitrocellulose membranes (dot–ELISA) for diagnosis and identification of plant pathogenic bacteria was tested. Five pathovars of Xanthomonas campestris and two antisera, one produced against pv. vesicatoria and the other against pv. translucens, were used in a model system. A 10-min incubation of the bacterial cells, dot blotted on membranes, in diluted sera, followed by either alkaline phosphatase conjugated protein A or goat antirabbit globulin, resulted in a specific reaction between the homologous serum and bacteria. Populations of 1000–2000 cfu per spot (ca. 0.3 cm2) could be detected with these reagents. The streptavidin–biotinylated peroxidase complex produced a definitive reaction with as few as 800 cfu, but cross-reactions became evident at the higher cell concentrations among all five pathovars in tests with both antisera. Cell-free extracts, obtained by centrifugation of boiled bacteria, reacted similarly to live cells. Unrelated bacteria did not react with either antiserum. Extracts of lesions from tomato and pepper leaves infected with X. campestris pv. vesicatoria reacted positively with the antiserum produced against this pathovar but not that produced with pv. translucens. Samples of supernatants from boiled lesions reacted with similar intensity as those from homogenized tissues.

scholarly journals Proteomic approaches to understanding the role of the cytoskeleton in host-defense mechanisms

2011 ◽  
Vol 8 (1) ◽  
pp. 117-126 ◽  
Author(s):  
Marko Radulovic ◽  
Jasminka Godovac-Zimmermann
Keyword(s):  
Host Defense ◽  
Defense Mechanisms

scholarly journals Interleukin-23 (IL-23)-IL-17 Cytokine Axis in Murine Pneumocystis carinii Infection

2007 ◽  
Vol 75 (6) ◽  
pp. 3055-3061 ◽  
Author(s):  
Xiaowen L. Rudner ◽  
Kyle I. Happel ◽  
Erana A. Young ◽  
Judd E. Shellito
Keyword(s):  
T Cells ◽  
Host Defense ◽  
Defense Mechanisms ◽  
Pneumocystis Carinii ◽  
Neutralizing Antibody ◽  
Wild Type ◽  
Pneumocystis Carinii Infection ◽  
Interleukin 23

ABSTRACT Host defense mechanisms against Pneumocystis carinii are not fully understood. Previous work in the murine model has shown that host defense against infection is critically dependent upon host CD4+ T cells. The recently described Th17 immune response is predominantly a function of effector CD4+ T cells stimulated by interleukin-23 (IL-23), but whether these cells are required for defense against P. carinii infection is unknown. We tested the hypothesis that P. carinii stimulates the early release of IL-23, leading to increases in IL-17 production and lung effector CD4+ T-cell population that mediate clearance of infection. In vitro, stimulation of alveolar macrophages with P. carinii induced IL-23, and IL-23p19 mRNA was expressed in lungs of mice infected with this pathogen. To address the role of IL-23 in resistance to P. carinii, IL-23p19−/− and wild-type control C57BL/6 mice were infected and their fungal burdens and cytokine/chemokine responses were compared. IL-23p19−/− mice displayed transient but impaired clearance of infection, which was most apparent 2 weeks after inoculation. In confirmatory studies, the administration of either anti-IL-23p19 or anti-IL-17 neutralizing antibody to wild-type mice infected with P. carinii also caused increases in fungal burdens. IL-17 and the lymphocyte chemokines IP-10, MIG, MIP-1α, MIP-1β, and RANTES were decreased in the lungs of infected IL-23p19−/− mice in comparison to their levels in the lungs of wild-type mice. In IL-23p19−/− mice infected with P. carinii, there were fewer effector CD4+ T cells in the lung tissue. Collectively, these studies indicate that the IL-23-IL-17 axis participates in host defense against P. carinii.

scholarly journals ER-associated degradation: Protein quality control and beyond

2014 ◽  
Vol 204 (6) ◽  
pp. 869-879 ◽  
Author(s):  
Annamaria Ruggiano ◽  
Ombretta Foresti ◽  
Pedro Carvalho
Keyword(s):  
Quality Control ◽  
Endoplasmic Reticulum ◽  
Protein Degradation ◽  
Control Systems ◽  
Protein Quality ◽  
Protein Quality Control ◽  
Secretory Proteins ◽  
Toxic Species ◽  
Cellular Factors

Even with the assistance of many cellular factors, a significant fraction of newly synthesized proteins ends up misfolded. Cells evolved protein quality control systems to ensure that these potentially toxic species are detected and eliminated. The best characterized of these pathways, the ER-associated protein degradation (ERAD), monitors the folding of membrane and secretory proteins whose biogenesis takes place in the endoplasmic reticulum (ER). There is also increasing evidence that ERAD controls other ER-related functions through regulated degradation of certain folded ER proteins, further highlighting the role of ERAD in cellular homeostasis.

scholarly journals Role of Specialized Pro-Resolving Mediators in Modifying Host Defense and Decreasing Bacterial Virulence

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6970
Author(s):  
Julianne M. Thornton ◽  
Kingsley Yin
Keyword(s):  
Host Defense ◽  
Host Response ◽  
Tissue Repair ◽  
Defense Mechanisms ◽  
Neutrophil Migration ◽  
Bacterial Virulence ◽  
Innate Immune ◽  
Bioactive Fatty Acids ◽  
Insight Into

Bacterial infection activates the innate immune system as part of the host’s defense against invading pathogens. Host response to bacterial pathogens includes leukocyte activation, inflammatory mediator release, phagocytosis, and killing of bacteria. An appropriate host response requires resolution. The resolution phase involves attenuation of neutrophil migration, neutrophil apoptosis, macrophage recruitment, increased phagocytosis, efferocytosis of apoptotic neutrophils, and tissue repair. Specialized Pro-resolving Mediators (SPMs) are bioactive fatty acids that were shown to be highly effective in promoting resolution of infectious inflammation and survival in several models of infection. In this review, we provide insight into the role of SPMs in active host defense mechanisms for bacterial clearance including a new mechanism of action in which an SPM acts directly to reduce bacterial virulence.

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