scholarly journals Innate Immune Effectors in Mycobacterial Infection

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Hiroyuki Saiga ◽  
Yosuke Shimada ◽  
Kiyoshi Takeda
Keyword(s):  
Immune Responses ◽  
Bacterial Infections ◽  
Mycobacterial Infection ◽  
Innate Immune ◽  
Pathogenic Microorganisms ◽  
Lipocalin 2 ◽  
Innate Immune Responses ◽  
Active Vitamin ◽  
Lectin Receptors ◽  
Adaptive Immune

Tuberculosis, which is caused by infection withMycobacterium tuberculosis(Mtb), remains one of the major bacterial infections worldwide. Host defense against Mtb is mediated by a combination of innate and adaptive immune responses. In the last 15 years, the mechanisms for activation of innate immunity have been elucidated. Toll-like receptors (TLRs) have been revealed to be critical for the recognition of pathogenic microorganisms including mycobacteria. Subsequent studies further revealed that NOD-like receptors and C-type lectin receptors are responsible for the TLR-independent recognition of mycobacteria. Several molecules, such as active vitamin D3, secretary leukocyte protease inhibitor, and lipocalin 2, all of which are induced by TLR stimulation, have been shown to direct innate immune responses to mycobacteria. In addition, Irgm1-dependent autophagy has recently been demonstrated to eliminate intracellular mycobacteria. Thus, our understanding of the mechanisms for the innate immune response to mycobacteria is developing.

scholarly journals The neuropeptide receptor NMUR-1 regulates the specificity of C. elegans innate immunity against pathogen infection

2021 ◽  
Author(s):  
Phillip Wibisono ◽  
Shawndra Wibisono ◽  
Jan Watteyne ◽  
Chia-Hui Chen ◽  
Durai Sellegounder ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Immune System ◽  
Immune Responses ◽  
Adaptive Immune System ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Immune Genes ◽  
C Elegans ◽  
Adaptive Immune ◽  
Functional Assays

A key question in current immunology is how the innate immune system generates high levels of specificity. Like most invertebrates, Caenorhabditis elegans does not have an adaptive immune system and relies solely on innate immunity to defend itself against pathogen attacks, yet it can still differentiate different pathogens and launch distinct innate immune responses. Here, we have found that functional loss of NMUR-1, a neuronal GPCR homologous to mammalian receptors for the neuropeptide neuromedin U, has diverse effects on C. elegans survival against various bacterial pathogens. Transcriptomic analyses and functional assays revealed that NMUR-1 modulates C. elegans transcription activity by regulating the expression of transcription factors, which, in turn, controls the expression of distinct immune genes in response to different pathogens. Our study has uncovered a molecular basis for the specificity of C. elegans innate immunity that could provide mechanistic insights into understanding the specificity of vertebrate innate immunity.

scholarly journals Infection triggers tumor regression through activation of innate immunity in Drosophila

2019 ◽  
Author(s):  
Camille Jacqueline ◽  
Jean-Philippe Parvy ◽  
Dominique Faugère ◽  
François Renaud ◽  
Dorothée Missé ◽  
...  
Keyword(s):  
Immune Responses ◽  
Tumor Size ◽  
Bacterial Infections ◽  
Tumor Regression ◽  
Acute Infection ◽  
Innate Immune ◽  
Immune Gene ◽  
Infectious Agents ◽  
Innate Immune Responses

AbstractThe pioneering work of Dr. William Coley has shown that infections can stimulate the immune system and improve tumor growth control. However, the immune mechanisms responsible for the protective role of infectious agents have still not been identified. Here, we investigated the role of innate immune pathways in tumor regression by performing experimental infections in genetically modified Drosophila that develop invasive neoplastic tumors. After quantifying tumor size, through image processing, and immune gene expression with transcriptomic analyses, we analyzed the link between tumor size and pathogen-induced immune responses thanks to a combination of statistical and mathematical modeling. Drosophila larvae infected with a naturally-occurring bacterium showed a smaller tumor size compared to controls and fungus-infected larvae, thanks to an increase expression of Imd and Toll pathways. Our mathematical model reinforces this idea by showing that repeated acute infection could results in an even higher decrease in tumor size. Thus, our study suggests that infectious agents can induce tumor regression through the alteration of innate immune responses. This phenomenon, currently neglected in oncology, could have major implications for the elaboration of new preventive and immunotherapeutic strategies.One Sentence SummaryBacterial infections can decrease cancer cell accumulation through stimulation of innate immune responses.

The innate immune system

2020 ◽  
pp. 307-314
Author(s):  
Paul Bowness
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Innate Immune System ◽  
Cell Types ◽  
Innate Immune ◽  
Microbial Pathogens ◽  
Innate Immune Responses ◽  
Adaptive Immune ◽  
System P ◽  
Different Cell Types

The innate immune system comprises evolutionarily ancient mechanisms that mediate first-line responses against microbial pathogens, and are also important in priming and execution of adaptive immune responses, and in defence against tumours. These responses, which recognize microbial non-self, damaged self, and absent self, are characterized by rapidity of action and they involve various different cell types, cell-associated receptors, and soluble factors. Previously thought to lack plasticity or memory, certain innate immune responses have recently been shown to be capable of ‘learning’ or ‘training’. Most cells of the innate immune system are derived from the myeloid precursors in the bone marrow. These include monocytes and their derivatives—macrophages and dendritic cells, blood granulocytes (neutrophils, basophils, and eosinophils), and tissue mast cells.

PRRs in pathogen recognition

2006 ◽  
Vol 1 (3) ◽  
pp. 299-313 ◽  
Author(s):  
Satoshi Uematsu ◽  
Shizuo Akira
Keyword(s):  
Pattern Recognition ◽  
Immune Responses ◽  
Pattern Recognition Receptors ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Pathogen Recognition ◽  
First Line ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Wide Range

AbstractThe innate immune system provides the first line of host defense against invading microorganisms before the development of adaptive immune responses. Innate immune responses are initiated by germline-encoded pattern recognition receptors (PRRs), which recognize specific structures of microorganisms. Toll-like receptors (TLRs) are pattern-recognition receptors that sense a wide range of microorganisms, including bacteria, fungi, protozoa and viruses. TLRs exist either on the cell surface or in the lysosome/endosome compartment and induce innate immune responses. Recently, cytoplasmic PRRs have been identified which detect pathogens that have invaded the cytosol. This review focuses on the pathogen recognition of PRRs in innate immunity.

scholarly journals Inflammation and Immune Response in COPD: Where Do We Stand?

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Nikoletta Rovina ◽  
Antonia Koutsoukou ◽  
Nikolaos G. Koulouris
Keyword(s):  
Immune Responses ◽  
Bacterial Infections ◽  
Severe Disease ◽  
Critical Role ◽  
Specific Pattern ◽  
Innate Immune ◽  
Danger Signal ◽  
Cd4 Cells ◽  
Adaptive Immune ◽  
Molecular Patterns

Increasing evidence indicates that chronic inflammatory and immune responses play key roles in the development and progression of COPD. Recent data provide evidence for a role in the NLRP3 inflammasome in the airway inflammation observed in COPD. Cigarette smoke activates innate immune cells by triggering pattern recognition receptors (PRRs) to release “danger signal”. These signals act as ligands to Toll-like receptors (TLRs), triggering the production of cytokines and inducing innate inflammation. In smokers who develop COPD there appears to be a specific pattern of inflammation in the airways and parenchyma as a result of both innate and adaptive immune responses, with the predominance of CD8+ and CD4+ cells, and in the more severe disease, with the presence of lymphoid follicles containing B lymphocytes and T cells. Furthermore, viral and bacterial infections interfere with the chronic inflammation seen in stable COPD and exacerbations via pathogen-associated molecular patterns (PAMPs). Finally, autoimmunity is another novel aspect that may play a critical role in the pathogenesis of COPD. This review is un update of the currently discussed roles of inflammatory and immune responses in the pathogenesis of COPD.

Coordinate actions of innate immune responses oppose those of the adaptive immune system duringSalmonellainfection of mice

2016 ◽  
Vol 9 (410) ◽  
pp. ra4-ra4 ◽  
Author(s):  
Andrew N. Hotson ◽  
Smita Gopinath ◽  
Monica Nicolau ◽  
Anna Khasanova ◽  
Rachel Finck ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Adaptive Immune System ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Adaptive Immune

scholarly journals Autophagy and Mitochondrial Homeostasis During Infection: A Double-Edged Sword

2021 ◽  
Vol 9 ◽  
Author(s):  
Sutian Wang ◽  
Kunli Zhang ◽  
Yuchang Yao ◽  
Jianhao Li
Keyword(s):  
Immune Responses ◽  
Energy Exchange ◽  
Biological Process ◽  
Innate Immune ◽  
Host Cells ◽  
Pathogenic Microorganisms ◽  
Innate Immune Responses ◽  
Mitochondrial Homeostasis ◽  
Mitochondrial Functions ◽  
Cellular Components

Autophagy, an essential biological process that affects immunity, is a powerful tool that host cells can use to defend against infections caused by pathogenic microorganisms. Autophagy can not only initiate innate immune responses but also degrade the cellular components that provide the conditions for removing the invaders. However, hyperactivated or inhibited autophagy leads to mitochondrial dysfunction, which is harmful to the host itself and is involved in many types of diseases. Mitochondria perform the functions of biological oxidation and energy exchange. In addition, mitochondrial functions are closely related to cell death, oxygen radical formation, and disease. Accumulation of mitochondrial metabolites affects survival of intracellular pathogens. In this mini-review, we focus on the crosstalk between autophagy and mitochondrial homeostasis during infection.

scholarly journals Functional Roles of Syk in Macrophage-Mediated Inflammatory Responses

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Young-Su Yi ◽  
Young-Jin Son ◽  
Chongsuk Ryou ◽  
Gi-Ho Sung ◽  
Jong-Hoon Kim ◽  
...  
Keyword(s):  
Immune Responses ◽  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Adaptive Immune Responses ◽  
Functional Roles ◽  
Pathogen Invasion ◽  
Adaptive Immune ◽  
Biological Responses

Inflammation is a series of complex biological responses to protect the host from pathogen invasion. Chronic inflammation is considered a major cause of diseases, such as various types of inflammatory/autoimmune diseases and cancers. Spleen tyrosine kinase (Syk) was initially found to be highly expressed in hematopoietic cells and has been known to play crucial roles in adaptive immune responses. However, recent studies have reported that Syk is also involved in other biological functions, especially in innate immune responses. Although Syk has been extensively studied in adaptive immune responses, numerous studies have recently presented evidence that Syk has critical functions in macrophage-mediated inflammatory responses and is closely related to innate immune response. This review describes the characteristics of Syk-mediated signaling pathways, summarizes the recent findings supporting the crucial roles of Syk in macrophage-mediated inflammatory responses and diseases, and discusses Syk-targeted drug development for the therapy of inflammatory diseases.

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