Human CD49a+ Lung Natural Killer Cell Cytotoxicity in Response to Influenza A Virus

Influenza A virus (IAV) is a major global public health burden due to its routine evasion of immunization strategies. Natural killer (NK) cells are innate cytotoxic cells with important antiviral activity in the human body, yet the function of these cells in the control of IAV infection is unclear. The aim of this study was to determine the role of lung NK cell cytotoxic responses to IAV. Human lung explants were infected ex vivo with IAV, and lung NK cell activation was analyzed by flow cytometry. Cytotoxic responses of NK cell subsets against IAV-infected macrophages were measured by flow cytometry and ELISA. Despite reports of hypofunctionality in the pulmonary environment, human lung-associated NK cells responded rapidly to ex vivo IAV infection, with upregulation of surface CD107a 24 h post-infection. The lung NK cell phenotype is similar in maturity and differentiation to NK cells of the peripheral blood but a unique CD56brightCD49a+CD103+CD69+ NK cell population was identified in the lung, indicating NK cell residency within this organ. In response to ex vivo IAV infection a greater proportion of resident CD56brightCD49a+ NK cells expressed surface CD107a compared with CD56brightCD49a− NK cells, suggesting a hyperfunctional NK cell population may be present within human lung tissue and could be the result of innate immunological training. Furthermore, NK cells provided significant antiviral, cytotoxic activity following contact with influenza-infected cells, including the production and release of IFN-γ and granzyme-B resulting in macrophage cell death. These results suggest that a resident, trained NK cell population are present in the human lung and may provide early and important control of viral infection. A greater understanding of this resident mucosal population may provide further insight into the role of these cells in controlling viral infection and generating appropriate adaptive immunity to IAV

Distinct emphysema subtypes defined by quantitative CT analysis are associated with specific pulmonary matrix metalloproteinases

BACKGROUND: Emphysema is characterised by distinct pathological sub-types, but little is known about the divergent underlying aetiology. Matrix-metalloproteinases (MMPs) are proteolytic enzymes that can degrade the extracellular matrix and have been identified as potentially important in the development of emphysema. However, the relationship between MMPs and emphysema sub-type is unknown. We investigated the role of MMPs and their inhibitors in the development of emphysema sub-types by quantifying levels and determining relationships with these sub-types in mild-moderate COPD patients and ex/current smokers with preserved lung function.METHODS: Twenty-four mild-moderate COPD and 8 ex/current smokers with preserved lung function underwent high resolution CT and distinct emphysema sub-types were quantified using novel local histogram-based assessment of lung density. We analysed levels of MMPs and tissue inhibitors of MMPs (TIMPs) in bronchoalveolar lavage (BAL) and assessed their relationship with these emphysema sub-types.RESULTS: The most prevalent emphysema subtypes in COPD subjects were mild and moderate centrilobular (CLE) emphysema, while only small amounts of severe centrilobular emphysema, paraseptal emphysema (PSE) and panlobular emphysema (PLE) were present. MMP-3, and -10 associated with all emphysema sub-types other than mild CLE, while MMP-7 and -8 had associations with moderate and severe CLE and PSE. MMP-9 also had associations with moderate CLE and paraseptal emphysema. Mild CLE occurred in substantial quantities irrespective of whether airflow obstruction was present and did not show any associations with MMPs.CONCLUSION: Multiple MMPs are directly associated with emphysema sub-types identified by CT imaging, apart from mild CLE. This suggests that MMPs play a significant role in the tissue destruction seen in the more severe sub-types of emphysema, whereas early emphysematous change may be driven by a different mechanism.TRIAL REGISTRATION: Trial registration number NCT01701869

Factors associated with coronary heart disease in COPD patients and controls

Background: COPD and coronary heart disease (CHD) frequently co-occur, yet which COPD phenotypes are most prone to CHD is poorly understood. The aim of this study was to see whether COPD patients did have a true higher risk for CHD than subjects without COPD, and to examine a range of potential factors associated with CHD in COPD patients and controls. Methods: 347 COPD patients and 428 non-COPD controls, were invited for coronary computed tomography angiography (CCTA) and pulmonary CT. Arterial blood gas, bioelectrical impedance and lung function was measured, and a detailed medical history taken. The CCTA was evaluated for significant coronary stenosis and calcium score (CaSc), and emphysema defined as >10% of total area <-950 Hounsfield units. Results: 12.6% of the COPD patients and 5.7% of the controls had coronary stenosis (p100 compared to 31.6% of the controls (p100 was 1.68 (1.12–2.53) in COPD patients compared with controls. Examining the risk of significant stenosis and CaSc>100 among COPD patients, no variable was associated with significant stenosis, whereas male sex [OR 2.85 (1.56–5.21)], age [OR 3.74 (2.42–5.77)], statin use [OR 2.23 (1.23–4.50)] were associated with CaSc>100, after adjusting for body composition, pack-years, C-reactive protein, use of angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), diabetes, emphysema score, GOLD category, exacerbation frequency, eosinophilia, and hypoxemia. Conclusion: COPD patients were more likely to have CHD, but neither emphysema score, lung function, exacerbation frequency, nor hypoxemia predicted presence of either coronary stenosis or CaSc>100.publishedVersio

Multiomics links global surfactant dysregulation with airflow obstruction and emphysema in COPD

RATIONALE: Pulmonary surfactant is vital for lung homeostasis as it reduces surface tension to prevent alveolar collapse and provides essential immune-regulatory and antipathogenic functions. Previous studies demonstrated dysregulation of some individual surfactant components in COPD. We investigated relationships between COPD disease measures and dysregulation of surfactant components to gain new insights into potential disease mechanisms. METHODS: Bronchoalveolar lavage proteome and lipidome were characterised in ex-smoking mild/moderate COPD subjects (n=26) and healthy ex-smoking (n=20) and never-smoking (n=16) controls using mass spectrometry. Serum surfactant protein analysis was performed. RESULTS: Total phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol, surfactant protein (SP)-B, SP-A and SP-D concentrations were lower in COPD versus controls (log2 fold change (log2FC) -2.0, -2.2, -1.5, -0.5, -0.7 and -0.5 (adjusted p<0.02), respectively) and correlated with lung function. Total phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol, SP-A, SP-B, SP-D, napsin A and CD44 inversely correlated with computed tomography small airways disease measures (expiratory to inspiratory mean lung density) (r= -0.56, r= -0.58, r= -0.45, r= -0.36, r= -0.44, r= -0.37, r= -0.40 and r= -0.39 (adjusted p<0.05)). Total phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol, SP-A, SP-B, SP-D and NAPSA inversely correlated with emphysema (% low-attenuation areas): r= -0.55, r= -0.61, r= -0.48, r= -0.51, r= -0.41, r= -0.31 and r= -0.34, respectively (adjusted p<0.05). Neutrophil elastase, known to degrade SP-A and SP-D, was elevated in COPD versus controls (log2FC 0.40, adjusted p=0.0390), and inversely correlated with SP-A and SP-D. Serum SP-D was increased in COPD versus healthy ex-smoking volunteers, and predicted COPD status (area under the curve 0.85). CONCLUSIONS: Using a multiomics approach, we demonstrate, for the first time, global surfactant dysregulation in COPD that was associated with emphysema, giving new insights into potential mechanisms underlying the cause or consequence of disease

The role of quantitative CT image analysis in understanding COPD

COPD is a heterogeneous disease with multiple clinical phenotypes and biological endotypes and the association between these are poorly understood. Novel quantitative analysis techniques permit objective measurements of pulmonary and extra-pulmonary manifestations of the disease. This thesis examines the role of quantitative CT analysis in exploring COPD, with the aim of showing that these techniques can potentially give important insights into the disease and explore the heterogeneity and underlying biology of the condition.CT image analysis was performed on two different cohorts of COPD subjects, which included quantification of emphysema, small airways disease and bronchial wall dimensions. Furthermore, novel analysis was also performed to quantify emphysema sub-types and body composition parameters. One of the cohorts was a small cross-sectional study of mild-moderate COPD subjects involving CT imaging and bronchoscopic sampling of the airways. BAL samples were analysed for inflammatory cytokines, white cell differential, matrix-metalloproteinases (MMPs) and microbiology. The other cohort was a larger 2 year longitudinal study of moderate-very severe COPD subjects who had CT imaging at enrolment and at 2 years. They also had careful characterisation with pulmonary function testing, exercise testing, sputum and blood analysis and clinical follow-up.The findings confirmed that CT image analysis could successfully measure emphysema and small airways disease with both having significant relationships with pulmonary function. Using these measures, I demonstrated a novel relationship between multiple MMPs and CT measured small airways disease, suggesting these proteases play an important role in the small airway remodelling that occurs in COPD. There were also associations between emphysema and MMPs, providing further evidence for their role in parenchymal destruction. In the larger cohort emphysema was independently associated with desaturation on exertion, but neither emphysema nor small airways disease had significant associations with blood or sputum inflammatory markers, sputum bacterial detection or exacerbation rate. On longitudinal analysis, emphysema progressed over a two period, although the causes for this were not apparent in my study. Quantification of airway dimensions were variable and unreliable and did not provide significant information about disease in either of my two cohorts.The findings from this study suggest that CT image analysis can be used to explore the disease and provides further rationale for future investigation into the use of image analysis in assessing different features of COPD

Present and future utility of CT scanning in the assessment and management of COPD

Computed Technology (CT) is the modality of choice for imaging the thorax and lung structure. In COPD it used to recognise the key morphological features of emphysema, bronchial wall thickening and gas trapping. Despite this its place in the investigation and management of COPD is yet to be determined and it is not routinely recommended. However, lung CT already has important clinical applications where it can be used to diagnose concomitant pathology and determine which patients with severe emphysemaare appropriate for lung volume reduction procedures. Furthermore novel quantitative analysis techniques permit objective measurements of pulmonary and extra-pulmonary manifestations of the disease. These techniques can give important insights into COPD and help explore the heterogeneity and underlying mechanisms of the condition. In time it is hoped that these techniques can be used in clinical trials to help develop disease specific therapy and ultimately as a clinical tool in identifying patients who would benefit most from new and existing treatments. This review discusses the current clinical applications for CT imaging in COPD and quantification techniques and its potential future role in stratifying disease for optimaloutcome

Dataset supporting the University of Southampton Doctoral Thesis &quot;The role of non-typeable haemophilus influenzae biofilms in host-microbial and microbial-microbial interactions in chronic obstructive pulmonary disease&quot;

Dataset supporting the University of Southampton Doctoral Thesis &quot;The role of non-typeable haemophilus influenzae biofilms in host-microbial and microbial-microbial interactions in chronic obstructive pulmonary disease&quot;. The dataset includes zipped file:Data_-_PURE.zip The research was funded by AstraZeneca. To date, this data has not been associated with any publications. Publications are in progress. This work was undertaken using a BBSRC iCASE PhD studentship (BB/T508135/1) awarded for JW&rsquo;s doctoral studies. </span

Systematic review of evidence for relationships between physiological and CT indices of small airways and clinical outcomes in COPD

Background: small airways disease (SAD) is considered pivotal in the pathology of COPD. There are numerous publications describing physiological and Computed Tomography (CT) imaging markers to detect SAD. However, there is no agreed gold standard and limited understanding of the clinical associations of these measures to disease outcomes.Methods: we conducted a systematic review using Embase, Medline and Pubmed to explore the relationship between physiological and CT SAD measures in COPD (GOLD Stages 1–4). Furthermore, evidence linking these physiological measures with defined clinical outcomes such as health status, functional assessment and exacerbation frequency were summarised.Results: the search yielded 1160 abstracts of which 19 met the search criteria. Six studies examined physiological and CT measures while 13 publications identified physiological measures and clinical outcomes. Strong correlations were seen between CT and physiological measures of SAD. Varying associations between physiological measures and defined clinical outcomes were noted.Conclusions: physiological and CT measures of SAD correlate and infer similar information. Physiological measures of SAD may offer valuable insight into clinical expression of the disease. A consensus on the standardisation and recommendation of tests to measure SAD is needed in order to better understand any clinical benefits of targeted drug therapy to the small airways

Human CD49a+ lung NK cell cytotoxicity in response to Influenza A Virus

Influenza A virus (IAV) is a major global public health burden due to its routine evasion of immunisation strategies. Natural Killer (NK) cells are innate cytotoxic cells with important antiviral activity in the human body, yet the function of these cells in the control of IAV infection is unclear. The aim of this study was to determine the role of lung NK cell cytotoxic responses to IAV. Human lung explants were infected ex vivo with IAV and lung NK cell activation was analysed by flow cytometry. Cytotoxic responses of NK cell subsets against IAV-infected macrophages were measured by flow cytometry and ELISA. Despite reports of hypofunctionality in the pulmonary environment, human lung-associated NK cells responded rapidly to ex vivo IAV infection, with upregulation of surface CD107a 24 h post-infection. The lung NK cell phenotype is similar in maturity and differentiation to NK cells of the peripheral blood but a unique CD56brightCD49a+CD103+CD69+ NK cell population was identified in the lung, indicating NK cell residency within this organ. In response to ex vivo IAV infection a greater proportion of resident CD56brightCD49a+ NK cells expressed surface CD107a compared to CD56brightCD49a- NK cells, suggesting a hyperfunctional NK cell population may be present within human lung tissue and could be the result of innate immunological training. Furthermore NK cells provided significant anti-viral, cytotoxic activity following contact with influenza infected cells, including the production and release of IFN-γ and Granzyme-B resulting in macrophage cell death. These results suggest that a resident, memory NK cell population are present in the human lung and may provide early and important control of viral infection. A greater understanding of this resident mucosal population may provide further insight into the role of these cells in controlling viral infection and generating appropriate adaptive immunity to IAV