Neutrophils and Bacterial Immune Evasion

Kobayashi, Scott D.; Małachowa, Natalia; DeLeo, Frank R.

doi:10.1159/000487756

Cited by 155 publications

(120 citation statements)

References 63 publications

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“…3,36 Although early neutrophil infiltration observed in tuberculosis has been attributed to the response of these cells to chemokines produced by local (or passing by) lymphoid cells primed by M. tuberculosis at the sites of infection, 37 some have suggested that neutrophils are the first cells to make contact with bacilli and that they are attracted by sensing the presence of these microorganisms through PRRs, chemotactic factors or soluble PAMPs. 38,39 In addition, neutrophils have been shown to rapidly migrate via the lymphatic system after M. bovis BCG intradermal vaccination and shuttle live bacilli to the draining lymph nodes. 40 Figure 8.…”

Section: Discussionmentioning

confidence: 99%

In vivoinduction of neutrophil extracellular traps byMycobacterium tuberculosisin a guinea pig model

et al. 2017

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In 2004, a novel mechanism of cellular death, called 'NETosis', was described in neutrophils. This mechanism, different from necrosis and apoptosis, is characterized by the release of chromatin webs admixed with microbicidal granular proteins and peptides (NETs). NETs trap and kill a variety of microorganisms. Diverse microorganisms, including Mycobacterium tuberculosis, are NET inducers in vitro. The aim of this study was to examine whether M. tuberculosis can also induce NETs in vivo and if the NETs are bactericidal to the microorganism. Guinea pigs were intradermally inoculated with M. tuberculosis H37Rv, and the production of NETs was investigated at several time points thereafter. NETs were detected as early as 30 min post-inoculation and were clearly evident by 4 h post-inoculation. NETs produced in vivo contained DNA, myeloperoxidase, elastase, histones, ROS and acid-fast bacilli. Viable and heat-killed M. tuberculosis, as well as Mycobacterium bovis BCG were efficient NET inducers, as were unilamellar liposomes prepared with lipids from M. tuberculosis. In vitro, guinea pig neutrophils also produced NETs in response to M. tuberculosis. However, neither the in vivo nor the in vitro-produced NETs were able to kill M. tuberculosis. Nevertheless, in vivo, neutrophils might propitiate recruitment and activation of more efficient microbicidal cells.

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Section: Discussionmentioning

confidence: 99%

In vivoinduction of neutrophil extracellular traps byMycobacterium tuberculosisin a guinea pig model

et al. 2017

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“…Many different agents and processes prime neutrophils to produce ROS (reviewed in Ref. [ 30]), including CXCL8 [31], which is a chemokine produced by different cell types including endothelial cells [32]. CXCL8 plays a key role in neutrophil adherence and transmigration during the inflammatory response [4,5].…”

Section: Discussionmentioning

confidence: 99%

L‐selectin expression is regulated by CXCL8‐induced reactive oxygen species produced during human neutrophil rolling

et al. 2018

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Neutrophils destroy invading microorganisms by phagocytosis by bringing them into contact with bactericidal substances, among which ROS are the most important. However, ROS also function as important physiological regulators of cellular signaling pathways. Here, we addressed the involvement of oxygen derivatives in the regulation of human neutrophil rolling, an essential component of the inflammatory response. Flow experiments using dihydroethidium‐preloaded human neutrophils showed that these cells initiate an early production of intracellular ROS during the rolling phase of the adhesion cascade, a phenomenon that required cell rolling, and the interaction of the chemokine receptor CXCR2 with their ligand CXCL8. Flow cytometry experiments demonstrated that L‐selectin shedding in neutrophils is triggered by ROS through an autocrine–paracrine mechanism. Preincubation of neutrophils with the NADPH oxidase complex inhibitor diphenyleniodonium chloride significantly increased the number of rolling neutrophils on endothelial cells. Interestingly, the same effect was observed when CXCL8 signaling was interfered using either a blocking monoclonal antibody or an inhibitor of its receptor. These findings indicate that, in response to CXCL8, neutrophils initiate ROS production during the rolling phase of the inflammatory response. This very early ROS production might participate in the modulation of the inflammatory response by inducing L‐selectin shedding in neutrophils.

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“…Neutrophils are the first leukocytes recruited to the site of infection. They play majo role in innate immune response [15]. Fig.…”

Section: Discussionmentioning

confidence: 99%

Immunomodulatory Effects of Ethanol Extract Artemisia Vulgaris L. In Male Rats

Marbun

Suwarso

Yuandani

2018

Asian J Pharm Clin Res

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Objective: This current study was conducted to investigate the immunomodulatory effects of ethanol extract of Artemisia vulgaris in male rats. Methods:Immunomodulatory activity was determined by measuring the carbon elimination rate, the total number of leukocytes and differential, as well as antibody titer. The treatment groups were divided into six groups, each group consisting of five male rats. The extract at doses of 50, 100, 200, and 400 mg/kg bw was administered orally for 7 days. The carbon elimination was measured using an ultraviolet-visible spectrophotometer. Results:The ethanol extract of A. vulgaris at doses of 50, 100, 200, and 400 mg/kg body weight increased the carbon elimination and increased the number of total leukocytes and differential leukocytes, especially neutrophils and neutrophils rod segments as compared to the negative control group (CMC-Na 0.5%) (p<0.05). Conclusion:The ethanol extract of A. vulgaris possesses immunomodulatory effect.

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Neutrophils and Bacterial Immune Evasion

Cited by 155 publications

References 63 publications

In vivoinduction of neutrophil extracellular traps byMycobacterium tuberculosisin a guinea pig model

In vivoinduction of neutrophil extracellular traps byMycobacterium tuberculosisin a guinea pig model

L‐selectin expression is regulated by CXCL8‐induced reactive oxygen species produced during human neutrophil rolling

Immunomodulatory Effects of Ethanol Extract Artemisia Vulgaris L. In Male Rats

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