T-cell infiltration of submucosa is observed in chronic rhinosinusitis (CRS). This T-cell infiltration leads to release of proinflammatory cytokines leading to epithelial activation.
Left-sided maxillar sinusitis (absence of the air transparency of left maxillar sinus). Image source: Wikipedia, public domain.
Sinus epithelial cells from patients with CRS were at an activated state with upregulated expression of:
- HLA-DR
- IFN-gamma-inducible protein 10
- monokine induced by IFN-gamma
- TNF-related apoptosis-inducing ligand (TRAIL)
The expressions of HLA-DR, TRAIL, and TNF receptor 2 were induced by IFN-gamma.
Epithelial cells started to undergo apoptosis 48 hours after IFN-gamma stimulation when the transcription of proinflammatory cytokines and chemokines decreased to initial levels.
The factors for apoptosis were T(H)1 cells and IFN-gamma.
Apoptosis was enhanced by Fas-Fas-ligand and TRAIL-TRAIL receptor 2 interactions.
Fas death domain (TNF receptor superfamily, member 6). Image source: Wikipedia, public domain.
This video describes the process by which apoptosis is activated by T cells. This video is from: Janeway's Immunobiology, 7th Edition Murphy, Travers, & Walport. Source: Garland Science.
Epithelial cell interaction with activated T cells is a biphasic phenomenon in CRS:
1. Initially T cells lead to activation and induction of proinflammatory functions of epithelial cells.
2. Apoptotic death ("exhausted cells die").
References:
Basinski TM, Holzmann D, Eiwegger T, Zimmermann M, Klunker S, Meyer N, Schmid-Grendelmeier P, Jutel M, Akdis CA. Dual nature of T-cell-epithelium interaction in chronic rhinosinusitis. J Allergy Clin Immunol. 2009 Jun 10.
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