Lymphocytes In Lung Tissue Research Articles

Transcriptome Analysis of Peripheral Blood Mononuclear Cells in Pulmonary Sarcoidosis.

BackgroundSarcoidosis is a granulomatous systemic disease of unknown etiology. Mononuclear cells such as macrophages or lymphocytes in lung tissue and hilar or mediastinal lymph nodes have been recognized to play an essential role in granuloma formation in pulmonary sarcoidosis. Peripheral blood mononuclear cells (PBMCs) consist of several immunocompetent cells and have been shown to play a mechanistic role in the pathogenesis of sarcoidosis. However, the genetic modifications that occur in bulk PBMCs of sarcoidosis remain to be elucidated.PurposeThis study aimed to explore the pathobiological markers of sarcoidosis in PBMCs by comparing the transcriptional signature of PBMCs from patients with pulmonary sarcoidosis with those of healthy controls by RNA sequencing.MethodsPBMC samples were collected from subjects with pulmonary sarcoidosis with no steroid/immunosuppressant drugs (n = 8) and healthy controls (n = 11) from August 2020 to April 2021, and RNA sequencing was performed with the PBMC samples.ResultsPrincipal component analysis using RNA sequencing datasets comparing pulmonary sarcoidosis with healthy controls revealed that the two groups appeared to be differentiated, in which 270 differentially expressed genes were found in PBMCs between sarcoidosis and healthy controls. Enrichment analysis for gene ontology suggested that some biological processes related to the pathobiology of sarcoidosis, such as cellular response to interleukin (IL)-1 and IFN-γ, regulation of IL-6 production, IL-8 secretion, regulation of mononuclear cell migration, and response to lipopolysaccharide, were involved. Enrichment analysis of the KEGG pathway indicated the involvement of tumor necrosis factor (TNF), toll-like receptor signaling, IL-17 signaling pathways, phagosomes, and ribosomes. Most of the genes involved in TNF and IL-17 signaling pathways and phagosomes were upregulated, while most of the ribosome-related genes were downregulated.ConclusionThe present study demonstrated that bulk gene expression patterns in PBMCs were different between patients with pulmonary sarcoidosis and healthy controls. The changes in the gene expression pattern of PBMCs could reflect the existence of sarcoidosis lesions and influence granuloma formation in sarcoidosis. These new findings are important to strengthen our understanding of the etiology and pathobiology of sarcoidosis and indicate a potential therapeutic target for sarcoidosis.

Effect of PD-1 Inhibitor Combined with X-Ray Irradiation on the Inflammatory Microenvironment and Lung Tissue Injury in Mice.

PurposeThis study was designed to evaluate the effects of PD-1 inhibitor on lung tissue morphology and the immune system in a mouse model of radiation-induced lung injury (RILI) and to assess interactions between radiation therapy and PD-1 inhibition.MethodsTwenty C57BL/6 mice were divided randomly into four groups of five mice each. Mice were treated with an anti-mouse PD-1 monoclonal antibody, whole thorax irradiation, both or neither. Lung tissue morphology and pathological changes were assessed by hematoxylin-eosin staining; lung fibrosis was assessed by Masson staining and analysis of hydroxyproline; CD3+, CD4+, and CD8+ T lymphocytes in lung tissues were detected immunohistochemically; and the concentrations of transforming growth factor-β1 (TGF-β1) and interleukin-6 (IL-6) in lung tissue were evaluated by cytokine multiplex analysis.ResultsLung injury scores and indicators of pulmonary fibrosis were higher in mice administration whole thorax irradiation than in control mice. Inflammatory infiltrate scores, alveoli deformation scores, collagen volume fractions and hydroxyproline contents in lung tissues were all significantly higher in mice administered PD-1 inhibitor plus irradiation than in the other three groups. Similarly, the percentages of CD3+ and CD8+T cells and the concentrations of IL-6 and TGF-β1 in lung tissue were significantly higher in mice treated with radiation and PD-1 inhibitor than in the other groups. However, PD-1 inhibitor and irradiation interacted significantly only in the elevation of TGF-β1 level.ConclusionWhole thorax X-ray irradiation in mice can cause pulmonary injury and fibrosis, which could be exacerbated by PD-1 inhibitors. Radiotherapy combined with PD-1 inhibitors may aggravate RILI by synergistically upregulating TGF-β1 expression, thereby affecting the immune-inflammatory microenvironment in the lungs.

A mouse allergic asthma model induced by shrimp tropomyosin

Allergic asthma remains an important worldwide health issue. Animal models are valuable for understanding the pathophysiological mechanisms of asthma and the development of effective therapeutics. This study aims to develop an alternative murine model induced by shrimp tropomyosin (ST) instead of ovalbumin (OVA). To investigate responses to short-term exposure to antigens, mice were sensitized with intraperitoneal injections of ST or ST plus aluminum adjuvant on days 0, 7, 14 followed by an intranasal challenge with ST for seven consecutive days. We reveal that sensitization with ST alone or ST plus aluminum induces significant levels of serum total IgE and ST-specific IgE in mice. Challenge results show that ST causes severe eosinophilic airway inflammation. Histology analysis of the lung tissues demonstrates airway inflammation and mucus hypersecretion within the bronchi in mice exposed to ST. Analysis of the cell composition in bronchoalveolar lavage fluid (BALF) shows a significant increase in eosinophil count in ST alone and ST plus aluminum groups. We also detect increased CD4+ T lymphocytes in lung tissues and production of helper T cell type 2-associated cytokines (IL-4 and IL-5) in BALF. In addition, airway hyperresponsiveness to methacholine in ST alone and ST plus aluminum groups is much higher than that in control groups. For the chronic model, mice were sensitized by ST or ST plus aluminum adjuvant for 3weeks and challenged with ST for 6weeks. We find severe structural changes in animals upon prolonged exposure to ST, including goblet cell hyperplasia, collagen deposition, and smooth muscle thickening. In conclusion, ST-induced asthma is a simple murine model for studying pathogenesis of asthma and evaluating new therapeutic drugs.

CD147-spike protein is a novel route for SARS-CoV-2 infection to host cells

In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2, no specific and effective drugs for treating this disease have been reported until today. Angiotensin-converting enzyme 2 (ACE2), a receptor of SARS-CoV-2, mediates the virus infection by binding to spike protein. Although ACE2 is expressed in the lung, kidney, and intestine, its expressing levels are rather low, especially in the lung. Considering the great infectivity of COVID-19, we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection. Here, we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein. The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody, Meplazumab, inhibits SARS-CoV-2 amplification. Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells, which can be neutralized by CD147 extracellular fragment. Viral loads are detectable in the lungs of human CD147 (hCD147) mice infected with SARS-CoV-2, but not in those of virus-infected wild type mice. Interestingly, virions are observed in lymphocytes of lung tissue from a COVID-19 patient. Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dose-dependent manner, which is specifically inhibited by Meplazumab. Furthermore, CD147 mediates virus entering host cells by endocytosis. Together, our study reveals a novel virus entry route, CD147-spike protein, which provides an important target for developing specific and effective drug against COVID-19.

Carbenoxolone decreases monocrotaline‑induced pulmonary inflammation and pulmonary arteriolar remodeling in rats by decreasing the expression of connexins in T lymphocytes.

The adaptive immune response mediated by T lymphocytes is a well-established factor in the pathogenesis of pulmonary inflammation. Changes in the expression of various connexins (Cxs) or disruption of connexin-mediated cellular communication in T lymphocytes contribute to inflammation or tissue remodeling. The aim of the present study was to investigate the potential therapeutic value of blocking Cxs in a monocrotaline (MCT)-induced pulmonary inflammation rat model. Carbenoxolone (CBX) was used to inhibit connexin-mediated cellular communication. An MCT rat model was established by intraperitoneal (i.p.) injection of a single dose of MCT (60 mg/kg), and CBX treatment (20 µg/kg/day, i.p.) was initiated on the day following MCT treatment for 28 days. Vehicle-treated male Sprague-Dawley rats were used as the negative control. The MCT rat model was evaluated by measuring the pulmonary artery flow acceleration time and right ventricular hypertrophy index (RVHI). Histopathological features of the lung tissues and pulmonary arteriolar remodeling were assessed. The proportions of T lymphocyte subtypes, Cx40/cx43 expression in the T cell subtypes and the cytokine levels in the plasma and the lung tissues were also analyzed. Pharmacological inhibition of Cxs using CBX attenuated MCT-induced right ventricular hypertrophy, pulmonary arteriolar remodeling, lung fibrosis and inflammatory cell infiltration by decreasing the RVHI, pulmonary arterial wall thickening, collagen deposition and pro-inflammatory cytokines production as well as CD3+ and CD4+ T cell accumulation in lung tissues of MCT-treated rats. Furthermore, flow cytometry analysis revealed that CBX may inhibit MCT-induced Cx40 and Cx43 expression in CD4+ and CD8+ T lymphocytes in lung tissues. The present study provides evidence that pharmacological inhibition of Cxs may attenuate MCT-induced pulmonary arteriolar remodeling and pulmonary inflammatory response, at least in part, by decreasing Cx expression. The results highlight the critical role of Cxs in T lymphocytes in the MCT-induced pulmonary inflammatory response and that targeting of Cxs may be a potential therapeutic method for treating pulmonary inflammatory diseases.

Suppression of airway inflammation by Illicium verum and trans-anethole

To develop an antiasthmatic agent, Illicium verum and its major components were evaluated for their ability to suppress airway inflammation. Furthermore we have studied the effects of trans-anethole compound on Treg cell-mediated suppression [1]. Asthma was induced in BALB/c mice by systemic sensitization to ovalbumin (OVA) followed by intratracheal, intraperitoneal, and aerosol allergen challenges. Illicium verum and its major components were orally administered for 4 weeks. We investigated their effects on airway hyperresponsiveness, pulmonary eosinophilic infiltration, various immune cell phenotypes, cytokine & cytospin measurements in bronchoalveolar lavage (BAL), Th2 cytokine production, OVA-specific IgE production, Th1/Th2 cytokine production, lung histology and immunofluorescence analysis in this mouse model of asthma [2]. Illicium verum and trans-anethole significantly (p < 0.05) inhibited OVA-induced increases in total cell counts, eosinophil counts, and IL-4, IL-5, and IL-13 levels recovered in bronchoalveolar lavage fluid in OVA-sensitized mice. trans-Anethole further substantially (p < 0.05) reduced the total IgE, eotaxin 2 levels, and CCR3 expression of BAL fluid. trans-Anethole also substantially (p < 0.05) increased the Foxp3 and TGF-b1 mRNA expression of BAL fluid. Histological studies showed that trans-anethole dramatically inhibited eosinophilia, and infiltration of lymphocytes in lung tissues. These results suggest that the anti-inflammatory and anti-asthmatic effects of Illicum verum and trans-anethole are exerted through upregulation of regulatory T cells.

Progressive changes in composition of lymphocytes in lung tissues from patients with non-small-cell lung cancer

Immune cell infiltration is a common feature of many human solid tumors. Innate and adaptative immune systems contribute to tumor immunosurveillance. We investigated whether tumors evade immune surveillance by inducing states of tolerance and/or through the inability of some immune subpopulations to effectively penetrate tumor nests. Immunohistochemistry and flow cytometry analysis were used to study the composition and distribution of immune subpopulations in samples of peripheral blood, tumor tissue (TT), adjacent tumor tissue (ATT), distant non-tumor tissue (DNTT), cancer nests, cancer stroma, and invasive margin in 61 non-small-cell lung cancer (NSCLC) patients. A significantly higher percentage of T and B cells and significantly lower percentage of NK cells were detected in TT than in DNTT. Memory T cells (CD4+CD45RO+, CD8+CD45RO+) and activated T cells (CD8+DR+) were more prevalent in TT. Alongside this immune activation, the percentage of T cells with immunosuppressive activity was higher in TT than in DNTT. B- cells were practically non-existent in tumor nests and were preferentially located in the invasive margin. The dominant NK cell phenotype in peripheral blood and DNTT was the cytotoxic phenotype (CD56+ CD16+), while the presence of these cells was significantly decreased in ATT and further decreased in TT. Finally, the immunologic response differed between adenocarcinoma and squamous cell carcinoma and according to the tumor differentiation grade. These findings on the infiltration of innate and adaptative immune cells into tumors contribute to a more complete picture of the immune reaction in NSCLC.

T cell immunohistochemistry refines lung transplant acute rejection diagnosis and grading

ObjectiveLung transplant volume has been increasing. However, inaccurate and uncertain diagnosis for lung transplant rejection hurdles long-term outcome due to, in part, interobserver variability in rejection grading. Therefore, a more reliable method to facilitate diagnosing and grading rejection is warranted.MethodRat lung grafts were harvested on day 3, 7, 14 and 28 post transplant for histological and immunohistochemical assessment. No immunosuppressive treatment was administered. We explored the value of interstitial T lymphocytes quantification by immunohistochemistry and compared the role of T cell immunohistochemistry with H&E staining in diagnosing and grading lung transplant rejection.ResultsTypical acute rejection from grade A1 to A4 was found. Rejection severity was heterogeneously distributed in one-third transplanted lungs (14/40): lesions in apex and center were more augmented than in the base and periphery of the grafts, respectively. Immunohistochemistry showed profound difference in T lymphocyte infiltration among grade A1 to A4 rejections. The coincidence rate of H&E and immunohistochemistry was 77.5%. The amount of interstitial T lymphocyte infiltration increased gradually with the upgrading of rejection. The statistical analysis demonstrated that the difference in the amount of interstitial T lymphocytes between grade A2 and A3 was not obvious. However, T lymphocytes in lung tissue of grade A4 were significantly more abundant than in other grades.ConclusionsRejection severity was heterogeneously distributed within lung grafts. Immunohistochemistry improves the sensitivity and specificity of rejection diagnosis, and interstitial T lymphocyte quantitation has potential value in diagnosing and monitoring lung allograft rejection.Virtual slidesThe virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1536075282108217.

CD4+ and CD8+ T lymphocytes in lung tissue of NSIP: Correlation with T lymphocytes in BALF

Nonspecific interstitial pneumonia (NSIP) is characterized by the interstitial infiltration T lymphocytes (TLs). Bronchoalveolar lavage fluid (BALF) has been used to analyze the inflammatory cells infiltrating in lung. The controversy about whether the BALF cellular profile reflects T lymphocytes in lung tissue still persists. Some studies found a positive correlation of cell composition between BALF and lung tissue, but others gave opposite conclusion. To investigate CD4+ and CD8+ T lymphocytes distribution in lung tissue of NSIP and the relationship with T lymphocytes in bronchoalveolar lavage. Thirty-seven patients diagnosed as NSIP were included. The pathological and BALF date were reviewed. The characteristics of TLs infiltration in different lung regions were investigated. The study included 28 women. The median age was 48 years. In lung tissue, CD4+ and CD8+ lymphocytes (counts/0.1mm2) were separately accounted in lymphoid follicle region (156.51 ± 90.70 vs 85.30 ± 43.75), small blood vessel region (66.58 ± 31.99 vs 58.43 ± 30.24), interstitial region (37.60 ± 19.40 vs 47.12 ± 33.42) and small airway region (26.59 ± 17.04 vs 40.18 ± 34.02). CD4+/CD8+ ratios in lymphoid follicle and small vessel > 1, in interstitium and small airway <1. The number of CD8+ lymphocytes in BALF was correlated with CD8+ lymphocytes around small airway (r = 0.360, p = 0.029) and in interstitial region (r = 0.451, p = 0.005). CD4+/CD8+ ratio in BALF was correlated with that in small airway region (r = 0.437, p = 0.007) and interstitial region (r = 0.468, p = 0.003). In NSIP, T lymphocytes were distributed in different regions of lung tissue. The CD8+ T lymphocytes and CD4+/CD8+ ratio in BALF reflect those in interstitium regions and around small airway of the lung.

Atorvastatin attenuates inflammatory infiltration and vascular remodeling in lung of hypercholesterolemia rabbits

ABSTRACTHypercholesterolemia contributes to cardiovascular diseases, but its direct effect on lung is little known. 3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) have been shown to exert numerous effects that are dependent and independent of their cholesterol-lowering property. The authors hypothesized that atorvastatin would attenuate hypercholesterolemia-induced lesion in lung. Fifteen rabbits were randomly divided into control group, high-cholesterol forage group, and atrovastatin treatment group. Body weight and blood lipid were measured. All lung tissue and pulmonary arteries were collected for histopathology and immunohistochemistry. Alveolar macrophages (AMs) were cultured and activation of nuclear factor (NF)-κB was detected. Concentrations of interleukin (IL)-6 were measured in serum, bronchoalveolar lavage fluid (BALF), and culture supernatants of AMs. Total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) of high-cholesterol forage group were higher than control group (P < .05). There were infiltrating of AMs and lymphocytes in lung tissue of high-cholesterol forage group. NF-κB activity in AMs and concentrations of IL-6 in serum, BALF, and culture supernatants of AMs were higher than those of control group (P < .01), and so were all vascular remodeling indexes. TC and LDL-C and other indexes of atrovastatin treatment group were decreased (P < .05). Hypercholesterolemia induced pulmonary inflammatory Infiltration and vascular remodeling. Atorvastatin attenuated inflammatory infiltration and vascular remodeling in lung of hypercholesterolemia rabbits.

Suppressor of Cytokine Signaling 3 Promotes Bone Marrow Cells to Differentiate into CD8+ T Lymphocytes in Lung Tissue via Up-Regulating Notch1 Expression

Suppressor of cytokine signaling 3 (SOCS3) expression in bone marrow cells (BMC) was up-regulated upon exposure to interleukin 6, lipopolysaccharide, or tumor-associated factors. But, how the up-regulated SOCS3 affects differentiation of BMCs is incompletely characterized. Here, we showed that SOCS3 promoted BMCs to intently differentiate into CD8 T cells. Importantly, lung can be as one athymus tissue for the BMCs to differentiate into CD8(+) T cells. Notch1 plays a critical role in the differentiation from SOCS3-transfected BMCs to CD8(+) T cells. We conclude that the up-regulated SOCS3 in some pathologic conditions, such as tumor and inflammation, might promote BMCs to differentiate into CD8(+) T lymphocytes in lung tissue via up-regulating Notch1 expression. This may represent a new mechanism against diseases such as tumor.

IL-17-producing T lymphocytes in lung tissue and in the bronchoalveolar space after exposure to endotoxin from Escherichia coli in vivo – effects of anti-inflammatory pharmacotherapy

Interleukin (IL)-17 may play a critical role for the innate immune response in mammals. However, little is known about its production in T lymphocytes in comparison with other cells, in lung tissue and in the bronchoalveolar space in vivo. Even less is known about the effects of anti-inflammatory pharmacotherapy on this IL-17 production. In this study on mice we show that one single, intranasal exposure to endotoxin from Escherichia coli increases extracellular IL-17 protein in bronchoalveolar (BAL) samples during 3 days, and is accompanied by a local increase in neutrophils and other inflammatory cells. This endotoxin exposure also elevates IL-17 mRNA in lung tissue samples. Moreover, after endotoxin exposure, the absolute number of CD3-positive cells containing intracellular IL-17 protein is increased as well; from a moderate cell number in lung tissue samples and from virtually none in BAL samples; with the number in lung tissue exceeding that observed in BAL samples. Notably, we also demonstrate that among the cells that contain intracellular IL-17 protein after endotoxin exposure, the percentage of CD3-positive cells is similar to that of CD3-negative cells in lung tissue. In contrast, CD3-negative cells dominate among IL-17-containing cells in BAL samples. A high systemic dose of a glucocorticoid receptor agonist attenuates the endotoxin-induced increase in extracellular IL-17 protein in BAL samples, IL-17 mRNA in lung tissue samples, and in IL-17-containing CD3-positive cells in BAL and lung tissue samples. This is also true for the endotoxin-induced accumulation of neutrophils and other inflammatory BAL cells in vivo. A systemic dose of a calcineurin phosphatase inhibitor exerts a less complete and more selective effect on the endotoxin-induced increase in extracellular IL-17 protein and on neutrophils in BAL samples. In vitro, endotoxin also increases extracellular IL-17 protein in a co-culture of CD3-positive spleen cells and adherent mononuclear BAL cells; an increase that was inhibited by a glucocorticoid as well as by a calcineurin phosphatase inhibitor. In conclusion, endotoxin-induced IL-17 production and release from T lymphocytes originates from cells that reside in lung tissue and from cells that have been recruited to the bronchoalveolar space. In both compartments, there is also a substantial number of cells other than T lymphocytes that contain IL-17 after endotoxin exposure. The sustained IL-17 production from T lymphocytes and the associated neutrophil accumulation may be inhibited non-selectively through glucocorticoid receptor stimulation and more selectively through calcineurin phosphatase inhibition.

Expression of chemokine receptors CXCR3 and CCR4 in lymphocytes of idiopathic nonspecific interstitial pneumonia

Little is known about the role of chemokines and their receptors interaction, which are essential for recruitment of selective lymphocyte subsets during inflammation, in the pathogenesis of idiopathic nonspecific interstitial pneumonia (NSIP). Recent studies have revealed Th1 and Th2 cells preferentially employ the chemokine receptors, CXCR3 and CCR4, respectively, in the process of accumulation into inflammatory sites. We evaluated the CXCR3 and CCR4 expression on infiltrated lymphocytes in lung tissues of 12 NSIP cases and 10 idiopathic pulmonary fibrosis (IPF) cases in our previous study. The number of CXCR3 positive lymphocytes of NSIP patients was significantly greater than that of IPF patients (261.1+/-145.1 vs. 64.9+/-27.0, P<0.01). The number of CCR4 positive lymphocytes of NSIP patients was significantly lower than that of IPF (9.5+/-8.3 vs.62.6+/-26.9, P<0.01). The CXCR3 to CCR4 ratio of NSIP patients was significantly greater than that of IPF patients (47.9+/-45.9 vs. 1.11+/-0.40, P<0.01). The differences of CXCR3 positive, CCR4 positive lymphocyte counts, and of CXCR3/CCR4 ratio between cellular and fibrosing NSIP were not significant. These results suggest that a Th1 pattern of chemokine receptor expression predominates in the lung interstitium of patients with NSIP but, in IPF patients, CCR4 might be relatively predominant, in contrast to the finding in NSIP patients, and that Th1/Th2 balance might be an important factor in the pathogenesis of NSIP.

CD8+ T lymphocytes in lung tissue from patients with idiopathic pulmonary fibrosis

BackgroundSeveral studies have implicated a role of inflammation in the pathogenesis of lung damage in idiopathic pulmonary fibrosis (IPF). Parenchymal lung damage leads to defects in mechanics and gas exchange and clinically manifests with exertional dyspnea. Investigations of inflammatory cells in IPF have shown that eosinophils, neutrophils and CD8+ TLs may be associated with worse prognosis. We wished to investigate by quantitative immunohistochemistry infiltrating macrophages, neutrophils and T lymphocytes (TLs) subpopulations (CD3+, CD4+ and CD8+) in lung tissue of patients with IPF and their correlation with lung function indices and grade of dyspnoea.MethodsSurgical biopsies of 12 patients with IPF were immunohistochemically stained with mouse monoclonal antibodies (anti-CD68 for macrophages, anti-elastase for neutrophils, and anti-CD3, anti-CD4, anti-CD8 for CD3+TLs, CD4+TLs, and CD8+TLs respectively). The number of positively stained cells was determined by observer-interactive computerized image analysis (SAMBA microscopic image processor). Cell numbers were expressed in percentage of immunopositive nuclear surface in relation to the total nuclear surface of infiltrative cells within the tissue (labeling Index). Correlations were performed between cell numbers and physiological indices [FEV1, FVC, TLC, DLCO, PaO2, PaCO2 and P(A-a)O2)] as well as dyspnoea scores assessed by the Medical Research Council (MRC) scale.ResultsElastase positive cells accounted for the 7.04% ± 1.1 of total cells, CD68+ cells for the 16.6% ± 2, CD3+ TLs for the 28.8% ± 7, CD4+ TLs for the 14.5 ± 4 and CD8+ TLs for the 13.8 ± 4. CD8+TLs correlated inversely with FVC % predicted (rs = -0.67, p = 0.01), TLC % predicted (rs = -0.68, p = 0.01), DLCO % predicted (rs = -0.61, p = 0.04), and PaO2 (rs = -0.60, p = 0.04). Positive correlations were found between CD8+TLs and P(A-a)O2 (rs = 0.65, p = 0.02) and CD8+TLs and MRC score (rs = 0.63, p = 0.02). Additionally, CD68+ cells presented negative correlations with both FVC % predicted (rs = -0.80, p = 0.002) and FEV1 % predicted (rs = -0.68, p = 0.01).ConclusionIn UIP/IPF tissue infiltrating mononuclear cells and especially CD8+ TLs are associated with the grade of dyspnoea and functional parameters of disease severity implicating that they might play a role in its pathogenesis.

The perforin mediated apoptotic pathway in lung injury and fibrosis

Aims: The perforin mediated pathway is the major pathway of cytotoxicity induced by activated T cells and natural killer cells, and may be involved in the development of pulmonary fibrosis....

Progressive increase of CD4+/CD45RC− lymphocytes after allograft rat lung transplantation: A marker of acute rejection

Background: Acute rejection remains one the most serious problems in lung transplantation. Although biopsy has been used for assessing the dysfunction of grafts, it is difficult to determine rejection at an early stage. Lymphocyte infiltration and activation play an important role in acute rejection of transplanted organs, and the dynamic change of lymphocyte subpopulations might be a marker to determine graft rejection after lung transplantation. Methods: A rat lung transplant model was used. Graft-infiltrating lymphocytes in lung tissues were examined by means of histology, and isolated cells were analyzed by means of flow cytometry. Phenotypes of lymphocytes in the regional and remote lymph nodes, spleen, peripheral blood, and bronchoalveolar lavage fluid were also measured by means of flow cytometry. Results: After allograft transplantation, increased lymphocytes were seen in allografts but not in isografts. In allografts the percentage of T cells increased from day 1 to day 5, whereas that of B cells was decreased. The CD4+/CD8+ ratio decreased in allografts. The proportion of CD4+/CD45RC− cells increased in the allografts, which was mainly due to the increase of CD45RC− cells in the total CD4+ cells. Similar changes were found in regional mediastinal lymph nodes but not in the mesenteric lymph nodes, spleen, or peripheral blood. Thus this is a specific response to lung allografts. Importantly, CD45RC− cells were significantly increased in the bronchoalveolar lavage fluid. Conclusion: Significant change of lymphocyte subpopulations is a sign of lymphocyte activation. Increased CD4+/CD45RC− cells in lung allografts could be an early marker of acute rejection, which can be examined by means of lung lavage and flow cytometry.J Thorac Cardiovasc Surg 2002;124:675-83

B7-1, B7-2 and class II MHC molecules in idiopathic pulmonary fibrosis and bronchiolitis obliterans-organizing pneumonia

Interstitial lung diseases are thought to be associated with the infiltration of activated T-lymphocytes. To induce an effective immune response, antigen-presenting cells have to not only present antigenic peptide with major histocompatibility complex (MHC) molecules to T-lymphocytes but also express B7 molecules. Therefore, the expression of B7-1, B7-2 and class II MHC molecules was investigated in lung tissues from patients with idiopathic pulmonary fibrosis (IPF) and bronchiolitis obliterans-organizing pneumonia (BOOP), and in normal lung parenchyma as a control, using immunohistochemical localization. B7-1 and B7-2 were aberrantly expressed in bronchiolar and alveolar epithelial cells, and class II MHC molecules were also aberrantly expressed in bronchiolar epithelial cells in IPF. B7-1 was aberrantly expressed in bronchiolar epithelial cells in BOOP. There was no significant difference in the expression of these proteins in alveolar macrophages between IPF and control subjects. However, B7-2 and class II MHC molecule expression in alveolar macrophages was decreased in BOOP compared with that in control subjects. Expression of CD28 and CTLA4, receptors for B7 molecules, was detected in infiltrating lymphocytes in lung tissues in IPF and BOOP. It was concluded that bronchiolar and alveolar epithelial cells may actively participate in the pathophysiology of idiopathic pulmonary fibrosis through the aberrant expression of B7 and class II major histocompatibility complex molecules. The dysregulation of these molecules in epithelial cells may lead to the activation of autoreactive T-lymphocytes, which might contribute to the pathogenesis of fibrosing lung diseases.

B7‐1, B7-2 and class II MHC molecules in idiopathic pulmonary fibrosis and bronchiolitis obliterans-organizing pneumonia

Interstitial lung diseases are thought to be associated with the infiltration of activated T-lymphocytes. To induce an effective immune response, antigen-presenting cells have to not only present antigenic peptide with major histocompatibility complex (MHC) molecules to T-lymphocytes but also express B7 molecules. Therefore, the expression of B7-1, B7-2 and class II MHC molecules was investigated in lung tissues from patients with idiopathic pulmonary fibrosis (IPF) and bronchiolitis obliterans-organizing pneumonia (BOOP), and in normal lung parenchyma as a control, using immunohistochemical localization. B7-1 and B7-2 were aberrantly expressed in bronchiolar and alveolar epithelial cells, and class II MHC molecules were also aberrantly expressed in bronchiolar epithelial cells in IPF. B7-1 was aberrantly expressed in bronchiolar epithelial cells in BOOP. There was no significant difference in the expression of these proteins in alveolar macrophages between IPF and control subjects. However, B7-2 and class II MHC molecule expression in alveolar macrophages was decreased in BOOP compared with that in control subjects. Expression of CD28 and CTLA4, receptors for B7 molecules, was detected in infiltrating lymphocytes in lung tissues in IPF and BOOP. It was concluded that bronchiolar and alveolar epithelial cells may actively participate in the pathophysiology of idiopathic pulmonary fibrosis through the aberrant expression of B7 and class II major histocompatibility complex molecules. The dysregulation of these molecules in epithelial cells may lead to the activation of autoreactive T-lymphocytes, which might contribute to the pathogenesis of fibrosing lung diseases.