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- Chu, Derek K, et al.
(författare)
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Indigenous enteric eosinophils control DCs to initiate a primary Th2 immune response in vivo.
- 2014
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Ingår i: Journal of Experimental Medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 211:8, s. 1657-1672
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Tidskriftsartikel (refereegranskat)abstract
- Eosinophils natively inhabit the small intestine, but a functional role for them there has remained elusive. Here, we show that eosinophil-deficient mice were protected from induction of Th2-mediated peanut food allergy and anaphylaxis, and Th2 priming was restored by reconstitution with il4(+/+) or il4(-/-) eosinophils. Eosinophils controlled CD103(+) dendritic cell (DC) activation and migration from the intestine to draining lymph nodes, events necessary for Th2 priming. Eosinophil activation in vitro and in vivo led to degranulation of eosinophil peroxidase, a granule protein whose enzymatic activity promoted DC activation in mice and humans in vitro, and intestinal and extraintestinal mouse DC activation and mobilization to lymph nodes in vivo. Further, eosinophil peroxidase enhanced responses to ovalbumin seen after immunization. Thus, eosinophils can be critical contributors to the intestinal immune system, and granule-mediated shaping of DC responses can promote both intestinal and extraintestinal adaptive immunity.
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| 2. |
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| 3. |
- Shen, Pamela, et al.
(författare)
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Cigarette smoke attenuates the nasal host response to Streptococcus pneumoniae and predisposes to invasive pneumococcal disease in mice.
- 2016
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Ingår i: Infection and Immunity. - 1098-5522. ; 84:5, s. 1536-1547
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Tidskriftsartikel (refereegranskat)abstract
- Streptococcus pneumoniae is a leading cause of invasive bacterial infections, with nasal colonization an important first step for disease. While cigarette smoking is a strong risk factor for invasive pneumococcal disease, underlying mechanisms remain unknown. This is partly due to a lack of clinically relevant animal models investigating nasal pneumococcal colonization in the context of cigarette smoke exposure. We present a model of nasal pneumococcal colonization in cigarette smoke-exposed mice and document, for the first time, that cigarette smoke predisposes to invasive pneumococcal infection and mortality in an animal model. Cigarette smoke increased the risk of bacteraemia and meningitis without prior lung infection. Mechanistically, deficiency in IL-1α or PAFR, an important host receptor thought to bind and facilitate pneumococcal invasiveness, did not rescue cigarette smoke-exposed mice from invasive pneumococcal disease. Importantly, we observed cigarette smoke to attenuate nasal inflammatory mediator expression, particularly that of neutrophil recruiting chemokines, normally elicited by pneumococcal colonization. Smoking cessation during nasal pneumococcal colonization rescued nasal neutrophil recruitment and prevented invasive disease in mice. We propose that cigarette smoke predisposes to invasive pneumococcal disease by suppressing inflammatory processes of the upper respiratory tract. Given that smoking prevalence remain high worldwide, these findings are relevant to the continued efforts to reduce invasive pneumococcal disease burden.
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