de Vries, J. J. C. | bioRxiv Science

bioRxiv2026

Ageing of the Upper Airway Epithelial Niche Limits Tissue-Resident T Cell Immunity

Respiratory tract infections are a major cause of morbidity and mortality among older adults worldwide. Yet, how ageing shapes protective immunity within the upper respiratory tract (URT) remains poorly understood. Here, we profiled the nasal immune landscape of young adults and older adults with and without frailty, using high-dimensional cytometry, proteomics, single-cell transcriptomics and T cell receptor (TCR) sequencing. Ageing was associated with a selective reduction of tissue-resident memory T (Trm) cells, independent of effector T cell numbers, inflammageing levels or frailty and was accompanied by a decline in T cell receptor repertoire stability. Trm cells from older adults also showed decreased steady-state IFN{gamma} expression, accompanied by reduced antiviral transcriptional programs in the mucosa. Mechanistically, in vitro PBMC-epithelium co-culture models revealed that older adults have a reduced capacity for Trm differentiation, which was associated with a diminished epithelial TGF-{beta} secretion, driven by reduced expression in ciliated epithelial cells. Together, these findings reveal that URT immunity deteriorates with age due to disrupted epithelial-immune crosstalk. This identifies the epithelial niche as a key regulator of mucosal immune ageing and suggests that enhancing TGF{beta} signaling may improve the effectiveness of mucosal airway vaccination strategies in older populations.

immunology↗

bioRxiv2019

The respiratory virome and exacerbations in patients with chronic obstructive pulmonary disease

IntroductionExacerbations are major contributors to morbidity and mortality in patients with chronic obstructive pulmonary disease (COPD), and respiratory bacterial and viral infections are an important trigger for the occurrence of such exacerbations. However, using conventional diagnostic techniques, a causative agent is not always found. Metagenomic next-generation sequencing (mNGS) allows analysis of the complete virome, but has not yet been applied in COPD exacerbations.\n\nObjectivesTo study the respiratory virome in nasopharyngeal samples during COPD exacerbations using mNGS.\n\nStudy design88 nasopharyngeal swabs from 63 patients from the Bergen COPD Exacerbation Study (2006-2010) were analysed by mNGS and in-house qPCR for respiratory viruses. Both DNA and RNA were sequenced simultaneously using an lllumina library preparation protocol with in-house adaptations.\n\nResultsBy mNGS, 23/88 samples tested positive. Sensitivity and specificity were both 96% for diagnostic targets (23/24 and 1067/1120, respectively). Viral pathogens only detected by mNGS were herpes simplex virus type 1 and coronavirus OC43. A positive correlation was found between Cq value and mNGS viral species reads (p=0.008). Patients with viral pathogens had lower percentages of bacteriophages (p<0.000). No correlation was found between viral reads (species and genus level) and clinical markers.\n\nConclusionsThe mNGS protocol used was highly sensitive and specific for semi-quantitative detection of respiratory viruses. Excellent negative predictive value implicates the power of mNGS to exclude any infectious cause in one test, with consequences for clinical decision making. Reduced abundance of bacteriophages in COPD patients with viral pathogens implicates skewing of the virome, and speculatively the bacterial population, during infection.

microbiology↗