scholarly journals Pattern Recognition Receptors and Cytokines inMycobacterium tuberculosisInfection—The Double-Edged Sword?

2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Md. Murad Hossain ◽  
Mohd-Nor Norazmi
Keyword(s):  
Pattern Recognition ◽  
Innate Immunity ◽  
Defense Mechanisms ◽  
Defense Mechanism ◽  
Adaptive Immune Response ◽  
Protective Role ◽  
Pattern Recognition Receptors ◽  
Immune Defense ◽  
Innate Immune ◽  
Intercellular Adhesion Molecule

Tuberculosis, an infectious disease caused byMycobacterium tuberculosis(Mtb), remains a major cause of human death worldwide. Innate immunity provides host defense against Mtb. Phagocytosis, characterized by recognition of Mtb by macrophages and dendritic cells (DCs), is the first step of the innate immune defense mechanism. The recognition of Mtb is mediated by pattern recognition receptors (PRRs), expressed on innate immune cells, including toll-like receptors (TLRs), complement receptors, nucleotide oligomerization domain like receptors, dendritic cell-specific intercellular adhesion molecule grabbing nonintegrin (DC-SIGN), mannose receptors, CD14 receptors, scavenger receptors, and FCγreceptors. Interaction of mycobacterial ligands with PRRs leads macrophages and DCs to secrete selected cytokines, which in turn induce interferon-γ- (IFNγ-) dominated immunity. IFNγand other cytokines like tumor necrosis factor-α(TNFα) regulate mycobacterial growth, granuloma formation, and initiation of the adaptive immune response to Mtb and finally provide protection to the host. However, Mtb can evade destruction by antimicrobial defense mechanisms of the innate immune system as some components of the system may promote survival of the bacteria in these cells and facilitate pathogenesis. Thus, although innate immunity components generally play a protective role against Mtb, they may also facilitate Mtb survival. The involvement of selected PRRs and cytokines on these seemingly contradictory roles is discussed.

scholarly journals Indoleamine 2,3-Dioxygenase 1 Is a Lung-Specific Innate Immune Defense Mechanism That Inhibits Growth of Francisella tularensis Tryptophan Auxotrophs

2010 ◽  
Vol 78 (6) ◽  
pp. 2723-2733 ◽  
Author(s):  
Kaitian Peng ◽  
Denise M. Monack
Keyword(s):  
Francisella Tularensis ◽  
Defense Mechanisms ◽  
Defense Mechanism ◽  
Immune Defense ◽  
The Body ◽  
Innate Immune ◽  
Microbial Pathogens ◽  
Immune Mechanisms ◽  
Indoleamine 2,3 Dioxygenase ◽  
Organ Specific

ABSTRACT Upon microbial challenge, organs at various anatomic sites of the body employ different innate immune mechanisms to defend against potential infections. Accordingly, microbial pathogens evolved to subvert these organ-specific host immune mechanisms to survive and grow in infected organs. Francisella tularensis is a bacterium capable of infecting multiple organs and thus encounters a myriad of organ-specific defense mechanisms. This suggests that F. tularensis may possess specific factors that aid in evasion of these innate immune defenses. We carried out a microarray-based, negative-selection screen in an intranasal model of Francisella novicida infection to identify Francisella genes that contribute to bacterial growth specifically in the lungs of mice. Genes in the bacterial tryptophan biosynthetic pathway were identified as being important for F. novicida growth specifically in the lungs. In addition, a host tryptophan-catabolizing enzyme, indoleamine 2,3-dioxygenase 1 (IDO1), is induced specifically in the lungs of mice infected with F. novicida or Streptococcus pneumoniae. Furthermore, the attenuation of F. novicida tryptophan mutant bacteria was rescued in the lungs of IDO1−/− mice. IDO1 is a lung-specific innate immune mechanism that controls pulmonary Francisella infections.

scholarly journals Sisters in arms: myeloid and tubular epithelial cells shape renal innate immunity

2013 ◽  
Vol 304 (10) ◽  
pp. F1243-F1251 ◽  
Author(s):  
Takashi Hato ◽  
Tarek M. El-Achkar ◽  
Pierre C. Dagher
Keyword(s):  
Pattern Recognition ◽  
Innate Immunity ◽  
Epithelial Cells ◽  
Immune Responses ◽  
Broad Class ◽  
Pattern Recognition Receptors ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Renal Epithelial Cells ◽  
Defensive Responses

The importance of innate immunity for survival is underscored by its presence at almost every level of the evolutionary tree of life. The task of “danger” recognition by the innate immune system is carried out by a broad class of pattern recognition receptors. These receptors are expressed in both hematopoietic and nonhematopoietic cells such as renal epithelial cells. Upon activation, pattern recognition receptors induce essentially two types of defensive responses: inflammation and phagocytosis. In this review, we highlight evidence that renal epithelial cells are endowed with such defensive capabilities and as such fully participate in renal innate immune responses.

scholarly journals Cooperative Immune Suppression by Escherichia coli and Shigella Effector Proteins

2018 ◽  
Vol 86 (4) ◽  
Author(s):  
Maarten F. de Jong ◽  
Neal M. Alto
Keyword(s):  
Escherichia Coli ◽  
Defense Mechanisms ◽  
Immune Defense ◽  
Effector Proteins ◽  
Innate Immune ◽  
Host Cells ◽  
Secretion Systems ◽  
Content Type ◽  
E Coli ◽  
Type Iii Secretion Systems

ABSTRACT The enteric attaching and effacing (A/E) pathogens enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC) and the invasive pathogens enteroinvasive E. coli (EIEC) and Shigella encode type III secretion systems (T3SS) used to inject effector proteins into human host cells during infection. Among these are a group of effectors required for NF-κB-mediated host immune evasion. Recent studies have identified several effector proteins from A/E pathogens and EIEC/ Shigella that are involved in suppression of NF-κB and have uncovered their cellular and molecular functions. A novel mechanism among these effectors from both groups of pathogens is to coordinate effector function during infection. This cooperativity among effector proteins explains how bacterial pathogens are able to effectively suppress innate immune defense mechanisms in response to diverse classes of immune receptor signaling complexes (RSCs) stimulated during infection.

scholarly journals Cnidarian Interaction with Microbial Communities: From Aid to Animal’s Health to Rejection Responses

Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 296 ◽  
Author(s):  
Loredana Stabili ◽  
Maria Parisi ◽  
Daniela Parrinello ◽  
Matteo Cammarata
Keyword(s):  
Microbial Communities ◽  
Environmental Changes ◽  
Defense Mechanism ◽  
Immune Defense ◽  
Innate Immune ◽  
Animal Disease ◽  
Normal Microbiota ◽  
Essential Components ◽  
Pathogenic Agents ◽  
And Behavior

The phylum Cnidaria is an ancient branch in the tree of metazoans. Several species exert a remarkable longevity, suggesting the existence of a developed and consistent defense mechanism of the innate immunity capable to overcome the potential repeated exposure to microbial pathogenic agents. Increasing evidence indicates that the innate immune system in Cnidarians is not only involved in the disruption of harmful microorganisms, but also is crucial in structuring tissue-associated microbial communities that are essential components of the Cnidarian holobiont and useful to the animal’s health for several functions, including metabolism, immune defense, development, and behavior. Sometimes, the shifts in the normal microbiota may be used as “early” bio-indicators of both environmental changes and/or animal disease. Here the Cnidarians relationships with microbial communities and the potential biotechnological applications are summarized and discussed.

Pattern recognition receptors and their roles in the host response to Helicobacter pylori infection

2021 ◽  
Author(s):  
Ileana Gonzalez ◽  
Paulina Araya ◽  
Ivan Schneider ◽  
Cristian Lindner ◽  
Armando Rojas
Keyword(s):  
Pattern Recognition ◽  
Helicobacter Pylori ◽  
Host Response ◽  
Pattern Recognition Receptors ◽  
Innate Immune ◽  
Host Cells ◽  
Proinflammatory Response ◽  
H Pylori ◽  
Cancer Pattern ◽  
Main Pattern

Helicobacter pylori ( H. pylori) infection is highly prevalent, affecting 4.4 billion people globally. This pathogen is a risk factor in the pathogenesis of more than 75% of worldwide cases of gastric cancer. Pattern recognition receptors are essential in the innate immune response to H. pylori infection. They recognize conserved pathogen structures and myriad alarmins released by host cells in response to microbial components, cytokines or cellular stress, thus triggering a robust proinflammatory response, which is crucial in H. pylori-induced gastric carcinogenesis. In this review, we intend to highlight the main pattern recognition receptors involved in the recognition and host response to H. pylori, as well as the main structures recognized and the subsequent inflammatory response.

scholarly journals Still Enigmatic: Innate Immunity in the Ctenophore Mnemiopsis leidyi

2019 ◽  
Vol 59 (4) ◽  
pp. 811-818 ◽  
Author(s):  
Nikki Traylor-Knowles ◽  
Lauren E Vandepas ◽  
William E Browne
Keyword(s):  
Innate Immunity ◽  
Immune System ◽  
Innate Immune System ◽  
Defense Mechanism ◽  
Innate Immune ◽  
Phylogenetic Position ◽  
Mnemiopsis Leidyi ◽  
Immunity Genes ◽  
Review Current

Abstract Innate immunity is an ancient physiological response critical for protecting metazoans from invading pathogens. It is the primary pathogen defense mechanism among invertebrates. While innate immunity has been studied extensively in diverse invertebrate taxa, including mollusks, crustaceans, and cnidarians, this system has not been well characterized in ctenophores. The ctenophores comprise an exclusively marine, non-bilaterian lineage that diverged early during metazoan diversification. The phylogenetic position of ctenophore lineage suggests that characterization of the ctenophore innate immune system will reveal important features associated with the early evolution of the metazoan innate immune system. Here, we review current understanding of the ctenophore immune repertoire and identify innate immunity genes recovered from three ctenophore species. We also isolate and characterize Mnemiopsis leidyi cells that display macrophage-like behavior when challenged with bacteria. Our results indicate that ctenophores possess cells capable of phagocytosing microbes and that two distantly related ctenophores, M. leidyi and Hormiphora californiensis, possess many candidate innate immunity proteins.

Sign in / Sign up

Export Citation Format

Share Document