PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 9973683

Pulmonary defence mechanisms.

L P Nicod
View original source ↗Export metadata ↓

Abstract

Lung defence involves a wide array of mechanisms needed to remove inhaled particles and organisms. The various innate immune processes which take place either in the central or in the more distant airways are reviewed. The recruitment and the development of an adaptive immunity following the innate response are described. This entails the production of secretory immunoglobulins in the airways and either the influx of polymorphonuclear neutrophils in the alveoli to phagocytose more or less opsonized organisms or the activation of the T lymphocyte response to improve the removal of intracellular pathogens.

Explore related subjects

BronchiDendritic CellsHumansImmunityInterleukinsLymphocytesMacrophages, AlveolarPulmonary AlveoliRespiratory SystemJournal ArticleReview

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

L P Nicod. 1999. Pulmonary defence mechanisms.. https://doi.org/10.1159/000029329

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Human bronchial epithelial cell transcriptome: gene expression changes following acute exposure to whole cigarette smoke in vitro.

Cigarette smoke is a complex mixture of more than 4,000 constituents. Its effects on cell biology are poorly understood, partly because whole smoke exposure in vitro is technically challenging. To investigate the effects of smoke on cell signaling and function, a three-dimensional air-liquid interface model of tracheobronchial epithelium, grown from primary human lung epithelial cells, was exposed to air or whole mainstream cigarette smoke for 1 h in a purpose-designed chamber. Gene expression profiles were then determined at 1, 6, and 24 h postexposure using Affymetrix HGU133-2 Plus microarrays. Cells from three different donors were used in the study, and the experiment was performed in triplicate for each donor. Genes significantly regulated by smoke, compared with the air control, in all experiments were determined. Genes exhibiting differential expression were assigned to functional categories and mapped to signaling pathways. Effects were observed on many cellular processes including xenobiotic metabolism, oxidant/antioxidant balance, and DNA damage and repair. Notably, there was marked downregulation of the transforming growth factor-beta pathway, which has not been previously reported. This study provides important data on the acute effects of whole cigarette smoke on mucociliary epithelium and may be used to gain a greater understanding of smoke toxicity.

Bronchi↗
PubMed2007

TLR3-mediated synthesis and release of eotaxin-1/CCL11 from human bronchial smooth muscle cells stimulated with double-stranded RNA.

Respiratory infections with RNA viruses, such as rhinovirus or respiratory syncytial virus, are a major cause of asthma exacerbation, accompanied by enhanced neutrophilic and/or eosinophilic inflammation of the airways. We studied the effects of dsRNA synthesized during RNA virus replication, and of its receptor, TLR3, on the synthesis of eosinophilic chemokines in bronchial smooth muscle cells (BSMC). Synthetic dsRNA, polyinosinic-cystidic acid (poly(I:C)), induced the synthesis of eosinophilic chemokines, eotaxin-1/CCL11 and RANTES/CCL5, from primary cultures of human BSMC, and IL-4 increased synergistically the synthesis of poly(I:C)-induced CCL11. A robust eosinophil chemotactic activity was released from BSMC stimulated with poly(I:C) and IL-4, which was mostly inhibited by preincubation with an anti-CCL11, but not with an anti-CCL5 Ab. Although the immunoreactivity of TLR3 was detectable on the cellular surface of BSMC by flow cytometric analysis, pretreatment with an anti-TLR3-neutralizing Ab failed to block the poly(I:C)-induced synthesis of CCL11. We have determined by confocal laser-scanning microscopy that the immunoreactivity of TLR3 was aggregated intracellularly in poly(I:C)-stimulated BSMC, colocalizing with fluorescein-labeled poly(I:C). The synthesis of CCL11 was prominently inhibited by the transfection of TLR3-specific small interfering RNA or by bafilomycin A1, an endosomal acidification inhibitor, further supporting the essential role played by intracellular TLR3 in the synthesis of poly(I:C)-induced CCL11 in BSMC. In conclusion, these observations suggest that, by activating intracellular TLR3 in BSMC, respiratory RNA virus infections stimulate the production of CCL11 and enhance eosinophilic inflammation of the airways in the Th2-dominant microenvironment.

Bronchi↗
PubMed2007

Sclerosing hemangioma with florid endobronchial and endobronchiolar growth.

Sclerosing hemangioma (SH) with endobronchial growth (SH-EG) is an extremely unusual form of SH. A case of SH-EG in a 47-year-old female is described. She suffered from a productive cough for 4 months. A chest CT scan revealed a well-circumscribed, parenchymal mass with endobronchial lesions continuously extending to the right main bronchus. Right upper sleeve lobectomy was carried out. The tumor was 4.8 x 3.5 cm in size, tan-brown, and elastically soft. It was located in the pulmonary parenchyma of the right upper lobe and continuously extended to the right upper bronchus. Furthermore, the main tumor also spread into segmental bronchi and peripheral bronchioles. Microscopically, the tumor consisted of round to cuboidal cells with papillary and solid patterns, partly showing sclerosis and hemorrhage. For 2.5 years after surgery, the patient has been well without recurrence or metastasis. Florid intrabronchial extension as seen in this case has never been documented in SH. To form an endobronchial component, it seems to be crucial that the parenchymal SH is located adjacent to the bronchus and involves it, followed by the destruction of the bronchial cartilage.

Bronchi↗