Chemokines and their receptors guiding T lymphocyte recruitment in lung inflammation

Tumor Necrosis Factor-Like Ligand 1A/Death Receptor 3 Signaling Regulates the Generation of Pathogenic T Helper 9 Cells in Experimental Crohn's Disease

BACKGROUND & AIMS

Death receptor 3 (DR3) and its ligand, tumor necrosis factor-like ligand 1A (TL1A), regulate the balance between effector and regulatory T cells in inflammatory bowel disease (IBD). Although interleukin 9 (IL9)-secreting T helper 9 (Th9) cells are linked to ulcerative colitis, their role in Crohn's disease (CD) is unclear. We investigated the role of DR3 signaling in Th9 cell differentiation in mouse models of CD-like ileitis and colitis.

METHODS

Polarized Th9 cells with functional DR3 and DR3-deficient Th9 cells from SAMP wild-type (Th9WT) and DR3-/-×SAMP knockout (Th9KO) mice, respectively, were characterized and adoptively transferred into Rag2-/- and SAMP×Rag2-/- recipients. Expression of Th9-associated molecules from experimental mice and IBD patients/controls was compared.

RESULTS

Th9WT possess a proinflammatory profile compared with Th9KO cells; conversely, ablation of DR3 signaling generates anti-inflammatory responses, as reflected by increased IL10-producing cells in DR3-/-×SAMP mice. RNA sequencing and phosphoproteomic analyses show that inflammatory pathways are robustly activated in Th9WT compared with Th9KO cells, whereas Th9 cells are detected in SAMP mice in vivo, and Th9-related genes display the same expression patterns in both experimental ileitis and IBD patients. Finally, in the T-cell adoptive transfer model, Th9KO cells are less colitogenic than Th9WT, whereas IL9 blockade diminishes the severity of intestinal inflammation, indicating a crucial role of functional DR3 receptor in the pathogenicity of Th9 cells.

CONCLUSIONS

We demonstrate that the functional DR3 receptor is essential for Th9 cell pathogenicity, revealing a new mechanism by which TL1A/DR3 signaling drives experimental CD-like ileitis. The TL1A/DR3/Th9 proinflammatory pathway may offer a novel therapeutic target for patients with CD.

Immune dysregulation in glycogen storage disease 1b extends beyond neutropenia

Glycogen Storage Disease type 1b (GSD1b) is a rare disease manifesting as hypoglycemia, recurrent infections and neutropenia, resulting from deleterious mutations in the SLC37A4 gene encoding the glucose-6-phosphate transporter. Classic treatment strategies in GSD1b focus on restoring neutrophil numbers and function; however, the immune defect is believed to be multifactorial and extensive immunophenotyping characterization is currently missing. Here we apply a systems immunology approach utilizing Cytometry by Time of Flight (CyTOF) to map the peripheral immune landscape of 6 GSD1b patients. When compared to control subjects, those with GSD1b had a significant reduction in immune sub-populations of classical monocytes, non-classical monocytes, and natural killer cells. Additionally, there was a preference towards a central versus an effector memory phenotype in multiple T cell populations. We also identified a global reduction of CD123, CD14, CCR4, CD24 and CD11b across several populations and a multi-cluster with upregulation of CXCR3, hinting at a potential role of impaired immune cell trafficking in the context of GSD1b. Taken together, our data suggest that that the immune impairment observed in GSD1b patients extends beyond neutropenia and affects innate and adaptive compartments, which may provide novel insights into the pathogenesis of this disorder.

Immune-related events in individuals with solid tumors on immunotherapy associate with Th17 and Th2 signatures

BACKGROUNDImmune-related adverse events (irAEs) and their associated morbidity/mortality are a key concern for patients receiving immune checkpoint inhibitors (ICIs). Prospective evaluation of the drivers of irAEs in a diverse pan-tumor cohort is needed to identify patients at greatest risk and to develop rational treatment and interception strategies.METHODSIn an observational study, we prospectively collected blood samples and performed regular clinical evaluations for irAEs in patients receiving ICI therapy as standard of care for solid tumors. We performed in-parallel analysis of cytokines by Luminex immunoassay and circulating immune cells by cytometry by time-of-flight (CyTOF) at baseline and on treatment to investigate mechanisms of irAEs.RESULTSWe enrolled 111 patients, of whom 40.5% developed a symptomatic irAE (grade ≥ 2). Development of a grade ≥ 2 irAE was positively associated with the use of combination ICI and a history of an autoimmune disorder. Early changes in T helper 17 (Th17) (IL-6, IL-17f), type 2 (IL-5, IL-13, IL-25), and type 1 (TNF-α) cytokine signatures and congruent on-treatment expansions of Th17 and Th2 effector memory (Th2EM) T cell populations in peripheral blood were positively associated with the development of grade ≥2 irAEs. IL-6 levels were also associated with inferior cancer-specific survival and overall survival.CONCLUSIONSIn a diverse, prospective pan-tumor cohort, Th17 and Th2 skewing during early ICI treatment was associated with the development of clinically relevant irAEs but not antitumor responses, providing possible targets for monitoring and therapeutic interventions.FUNDINGJohns Hopkins Bloomberg-Kimmel Institute for Cancer Immunotherapy, the NCI SPORE in Gastrointestinal Cancers (P50 CA062924), NCI grant (R50CA243627 to LD), the NIH Center Core Grant (P30 CA006973), Swim Across America (to MY), NIAMS (K23AR075872 to LC), and imCORE-Genentech grant 137515 (to Johns Hopkins Medicine on behalf of MY).

Imaging Identifies Superior Inflammation Targeting of M1 Macrophages for Cryo-Shocked Cell Pulmonary Drug Delivery to Treat Acute Lung Injury

In the realm of combating acute lung injury (ALI) induced by a myriad of triggers including sepsis, pneumonia, aspiration, trauma, and pancreatitis, macrophages emerge as crucial players. However, traditional treatments such as systemic administration of glucocorticoids come with the baggage of severe side effects, curtailing their utility. Enter an innovative solution: a biomimetic drug delivery system fashioned from cryo-shocked macrophages, tailored for pulmonary drug delivery. Positron emission tomography (PET) imaging has shed light on the remarkable targeting abilities of live M1 macrophages, showcasing their unparalleled efficacy in homing in on local inflammatory foci when contrasted with naive, M1, and M2 macrophages. Building upon this foundation, liquid nitrogen-treated (LNT) M1 macrophages are developed, engineered to preserve their inflammation-targeting prowess while sidestepping the release of pro-inflammatory cytokines. This breakthrough allows for the delivery of glucocorticoids directly to inflamed lung tissues, efficiently quelling inflammation and mitigating pulmonary edema while drastically reducing systemic drug exposure. Inspired by the effectiveness of live M1 macrophages, the potential of glucocorticoid-loaded LNT M1 macrophages are harnessed, utilizing them as a stealthy "Trojan horse" in the battle against pneumonia-induced ALI. This innovative approach holds promise as a safe and potent treatment avenue for acute lung injury.

Adenosine A2AR in viral immune evasion and therapy: unveiling new avenues for treating COVID-19 and AIDS

Adenosine is a neuro- and immunomodulator that functions via G protein-coupled cell surface receptors. Several microbes, including viruses, use the adenosine signaling pathway to escape from host defense systems. Since the recent research developments in its role in health and disease, adenosine and its signaling pathway have attracted attention for targeting to treat many diseases. The therapeutic role of adenosine has been extensively studied for neurological, cardiovascular, and inflammatory disorders and bacterial pathophysiology, but published data on the role of adenosine in viral infections are lacking. Therefore, the purpose of this review article was to explain in detail the therapeutic role of adenosine signaling against viral infections, particularly COVID-19 and HIV. Several therapeutic approaches targeting A2AR-mediated pathways are in development and have shown encouraging results in decreasing the intensity of inflammatory reaction. The hypoxia-adenosinergic mechanism provides protection from inflammation-mediated tissue injury during COVID-19. A2AR expression increased remarkably in CD39 + and CD8 + T cells harvested from HIV patients in comparison to healthy subjects. A combined in vitro treatment performed by blocking PD-1 and CD39/adenosine signaling produced a synergistic outcome in restoring the CD8 + T cells funstion in HIV patients. We suggest that A2AR is an ideal target for pharmacological interventions against viral infections because it reduces inflammation, prevents disease progression, and ultimately improves patient survival.

Acrylamide, an air pollutant, enhances allergen-induced eosinophilic lung inflammation via group 2 innate lymphoid cells

Air pollution significantly impacts the aggravation of asthma. Exposure to acrylamide, a volatile organic compound in tobacco smoke, is associated with elevated risks of allergy-related outcomes among active smokers. As group 2 innate lymphoid cells (ILC2s) can act as an environmental sensor and significantly contribute to protease allergen-induced lung inflammation, we aimed to elucidate the causal relationship and how inhaled acrylamide worsens allergic lung inflammation via ILC2s. Intranasal acrylamide exposure at nanomolar levels significantly enhanced allergen-induced or recombinant mouse interleukin-33-induced lung inflammation in C57BL/6 mice or Rag1-/- mice, respectively. The cardinal features of lung inflammation included accumulated infiltration of ILC2s and eosinophils. Transcriptomic analysis revealed a gene expression pattern associated with proliferation-related pathways in acrylamide-treated ILC2s. Western blotting revealed significantly higher expression of Ras and phospho-Erk in acrylamide-treated ILC2s than the control, suggesting Ras-Erk signaling pathway involvement. Ex vivo and in vitro analysis showed that acrylamide treatment mainly increased Ki-67+ ILC2s and the cell number of ILC2s whereas PD98059, a highly selective Erk inhibitor, effectively counteracted the acrylamide effect. Intratracheal administration of acrylamide-treated ILC2s significantly enhanced eosinophil infiltration in Rag1-/- mice. This study suggests that airborne acrylamide may enhance the severity of allergen-induced airway eosinophilic inflammation, partly via altering ILC2 proliferative activity.

Immune dysregulation in Glycogen Storage Disease 1b - a CyTOF approach

Glycogen Storage Disease type 1b (GSD1b) is a rare disease manifesting as hypoglycemia, recurrent infections and neutropenia, resulting from deleterious mutations in the SLC37A4 gene encoding the glucose-6-phosphate transporter. The susceptibility to infections is thought to be attributed not only to the neutrophil defect, though extensive immunophenotyping characterization is currently missing. Here we apply a systems immunology approach utilizing Cytometry by Time Of Flight (CyTOF) to map the peripheral immune landscape of 6 GSD1b patients. When compared to control subjects, those with GSD1b had a significant reduction in anti-inflammatory macrophages, CD16+ macrophages, and Natural Killer cells. Additionally, there was a preference towards a central versus an effector memory phenotype in multiple T cell populations, which may suggest that these changes stem from an inability of activated immune cell populations to undergo the appropriate switch to glycolytic metabolism in the hypoglycemic conditions associated with GSD1b. Furthermore, we identified a global reduction of CD123, CD14, CCR4, CD24 and CD11b across several populations and a multi-cluster upregulation of CXCR3, hinting at a potential role of impaired immune cell trafficking in the context of GSD1b. Taken together, our data indicates that that the immune impairment observed in GSD1b patients extends far beyond neutropenia and encompasses innate and adaptive compartments, which may provide novel insights into the pathogenesis of this disorder.

Mitochondrial transport, partitioning and quality control at the heart of cell proliferation and fate acquisition

Mitochondria are essential to cell homeostasis, and alterations in mitochondrial distribution, segregation or turnover have been linked to complex pathologies such as neurodegenerative diseases or cancer. Understanding how these functions are coordinated in specific cell types is a major challenge to discover how mitochondria globally shape cell functionality. In this review, we will first describe how mitochondrial transport and dynamics are regulated throughout the cell cycle in yeast and in mammals. Second, we will explore the functional consequences of mitochondrial transport and partitioning on cell proliferation, fate acquisition, stemness, and on the way cells adapt their metabolism. Last, we will focus on how mitochondrial clearance programs represent a further layer of complexity for cell differentiation, or in the maintenance of stemness. Defining how mitochondrial transport, dynamics and clearance are mutually orchestrated in specific cell types may help our understanding of how cells can transition from a physiological to a pathological state.

Therapeutic Targeting of Hypoxia-A2-Adenosinergic Pathway in COVID-19 Patients

The hypoxia-hypoxia-inducible factor (HIF)-1α-A2-adenosinergic pathway protects tissues from inflammatory damage during antipathogen immune responses. The elimination of this physiological tissue-protecting mechanism by supplemental oxygenation may contribute to the high mortality of oxygen-ventilated COVID-19 patients by exacerbating inflammatory lung damage. Restoration of this pathway with hypoxia-adenosinergic drugs may improve outcomes in these patients.

TIPE polarity proteins are required for mucosal deployment of T lymphocytes and mucosal defense against bacterial infection

Mucosal surfaces are continuously exposed to, and challenged by, numerous commensal and pathogenic organisms. To guard against infections, a majority of the thymus-derived T lymphocytes are deployed at the mucosa. Although chemokines are known to be involved in the mucosal lymphocyte deployment, it is not clear whether lymphocytes enter the mucosa through directed migration or enhanced random migration. Here we report that TIPE (tumor necrosis factor-α-induced protein 8 (TNFAIP8)-like) proteins mediate directed migration of T lymphocytes into lung mucosa, and they are crucial for mucosal immune defense against Streptococcus pneumoniae infection. Knockout of both Tnfaip8 and Tipe2, which encode polarity proteins that control the directionality of lymphocyte migration, significantly reduced the numbers of T lymphocytes in the lung of mice. Compared with wild-type mice, Tnfaip8^−/−Tipe2^−/− mice also developed more severe infection with more pathogens entering blood circulation upon nasal Streptococcus pneumoniae challenge. Single-cell RNA-sequencing analysis revealed that TIPE proteins selectively affected mucosal homing of a unique subpopulation of T cells, called “T cells-2”, which expressed high levels of Ccr9, Tcf7, and Rag1/2 genes. TNFAIP8 and TIPE2 appeared to have overlapping functions since deficiency in both yielded the strongest phenotype. These data demonstrate that TIPE family of proteins are crucial for lung mucosal immunity. Strategies targeting TIPE proteins may help develop mucosal vaccines or treat inflammatory diseases of the lung.

Comprehensive transcriptome analysis of peripheral blood unravels key lncRNAs implicated in ABPA and asthma

Allergic bronchopulmonary aspergillosis (ABPA) is a complex hypersensitivity lung disease caused by a fungus known as Aspergillus fumigatus. It complicates and aggravates asthma. Despite their potential associations, the underlying mechanisms of asthma developing into ABPA remain obscure. Here we performed an integrative transcriptome analysis based on three types of human peripheral blood, which derived from ABPA patients, asthmatic patients and health controls, aiming to identify crucial lncRNAs implicated in ABPA and asthma. Initially, a high-confidence dataset of lncRNAs was identified using a stringent filtering pipeline. A comparative mutational analysis revealed no significant difference among these samples. Differential expression analysis disclosed several immune-related mRNAs and lncRNAs differentially expressed in ABPA and asthma. For each disease, three sub-networks were established using differential network analysis. Many key lncRNAs implicated in ABPA and asthma were identified, respectively, i.e., AL139423.1-201, AC106028.4-201, HNRNPUL1-210, PUF60-218 and SREBF1-208. Our analysis indicated that these lncRNAs exhibits in the loss-of-function networks, and the expression of which were repressed in the occurrences of both diseases, implying their important roles in the immune-related processes in response to the occurrence of both diseases. Above all, our analysis proposed a new point of view to explore the relationship between ABPA and asthma, which might provide new clues to unveil the pathogenic mechanisms for both diseases.

Influence of Galectin-3 on the Innate Immune Response during Experimental Cryptococcosis

Cryptococcus neoformans, the causative agent of cryptococcosis, is the primary fungal pathogen that affects the immunocompromised individuals. Galectin-3 (Gal-3) is an animal lectin involved in both innate and adaptive immune responses. The present study aimed to evaluate the influence of Gal-3 on the C. neoformans infection. We performed histopathological and gene profile analysis of the innate antifungal immunity markers in the lungs, spleen, and brain of the wild-type (WT) and Gal-3 knockout (KO) mice during cryptococcosis. These findings suggest that Gal-3 absence does not cause significant histopathological alterations in the analyzed tissues. The expression profile of the genes related to innate antifungal immunity showed that the presence of cryptococcosis in the WT and Gal-3 KO animals, compared to their respective controls, promoted the upregulation of the pattern recognition receptor (PRR) responsive to mannose/chitin (mrc1) and a gene involved in inflammation (ccr5), as well as the downregulation of the genes related to signal transduction (card9, fos, ikbkb, jun) and PRRs (cd209a, colec12, nptx1). The absence of Gal-3, in fungal infection, a positively modulated gene involved in phagocytosis (sftpd) and negatively genes involved in signal transduction (syk and myd88), proinflammatory cytokines il-1β and il-12b and cd209a receptor. Therefore, our results suggest that Gal-3 may play an essential role in the development of antifungal immune responses against cryptococcosis.

Triterpenoid compound betulin attenuates allergic airway inflammation by modulating antioxidants, inflammatory cytokines and tissue transglutaminase in ovalbumin-induced asthma mice model

OBJECTIVES

This study hypothesized that to analyse the anti-inflammatory effect of triterpenoid compound betulin in ovalbumin (OVA)-induced asthmatic mice.

METHODS

In this study, betulin was intraperitoneally administered in OVA-challenged and sensitized mice. The effect of betulin on inflammatory cells, lung function, reactive oxygen species (ROS) production, antioxidants status, oxidative stress markers, serum IgE level and inflammatory cytokines status in BALF was examined by enzyme-linked immunosorbent assay. The expression of tTG, TGF-β1, MMP-9 and TIMP-1 in lung tissue was scrutinized by RT-qPCR analysis, and the expression of TREM-1, p-IκB-α and NF-κBp65 proteins in lung tissue was examined by western blot analysis.

KEY FINDINGS

We found that the betulin treatment has effectively attenuated the proliferation of inflammatory cells, reduced the ROS generation, elevated the antioxidant enzymes and attenuated the level of oxidative markers in asthma induced mice. Moreover, reduced the level of serum IgE and pro-inflammatory cytokines, and increased the anti-inflammatory cytokine IFN-γ. Betulin treatment down-regulated the expression of MMP-9, tTG and TGF-β1 genes; moreover, betulin treatment effectively down-regulated the TREM-1, p-IκB-α and NF-κBp65 proteins level in lung.

CONCLUSION

Betulin exhibited effective anti-asthmatic activity by attenuating the accumulation of inflammatory cells, expression of tTG, TGF-β1 and MMP-9 genes in lung tissue.

Age-Dependent Differences in T-Cell Responses to Influenza A Virus

Respiratory infections from influenza A virus (IAV) cause substantial morbidity and mortality in children relative to adults. T cells play a critical role in the host response to IAV by supporting the innate and humoral responses, mediating cytotoxic activity, and promoting recovery. There are age-dependent differences in the number, subsets, and localization of T cells, which impact the host response to pathogens. In this article, we first review how T cells recognize IAV and examine differences in the resting T-cell populations between juveniles and adults. Next, we describe how the juvenile CD4⁺, CD8⁺, and regulatory T-cell responses compare with those in adults and discuss the potential physiologic and clinical consequences of the differences. Finally, we explore the roles of two unconventional T-cell types in the juvenile response to influenza, natural-killer T cells and γδ T cells. A clear understanding of age-dependent differences in the T-cell response is essential to developing therapies to prevent or reverse the deleterious effects of IAV in children.

Elucidating the Molecular Interactions of Chemokine CCL2 Orthologs with Flavonoid Baicalin

An integrated and controlled migration of leukocytes is necessary for the legitimate functioning and maintenance of the immune system. Chemokines and their receptors play a decisive role in regulating the leukocyte migration to the site of inflammation, a phenomena often referred to as chemotaxis. Chemokines and their receptors have become significant targets for therapeutic intervention considering their potential to regulate the immune system. Monocyte chemoattractant protein-1 (MCP-1/CCL2) is a preeminent member of CC chemokine family that facilitates crucial roles by orchestrating the recruitment of monocytes into inflamed tissues. Baicalin (BA), a major bioactive flavonoid, has been reported to attenuate chemokine-regulated leukocyte trafficking. However, no molecular details pertaining to its direct binding to chemokine(s)/receptor(s) are available till date. In the current study, using an array of monomers/dimers of human and murine CCL2 orthologs (hCCL2/mCCL2), we have shown that BA binds to the CCL2 protein specifically with nanomolar affinity (K _d = 270 ± 20 nM). NMR-based studies established that BA binds CCL2 in a specific pocket involving the N-terminal, β1- and β3-sheets. Docking studies suggested that the residues T16, N17, R18, I20, R24, K49, E50, I51, and C52 are majorly involved in complex formation through a combination of H-bonds and hydrophobic interactions. As the residues R18, R24, and K49 of hCCL2 are crucial determinants of monocyte trafficking through receptor/glycosaminoglycans (GAG) binding in CCL2 human/murine orthologs, we propose that baicalin engaging these residues in complex formation will result in attenuation of CCL2 binding to the receptor/GAGs, thus inhibiting the chemokine-regulated leukocyte trafficking.

Animal models of emphysema

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a common chronic respiratory disease of human beings characterized by not fully reversible airflow limitation. Emphysema is the main pathological feature of COPD which causes high mortality worldwide every year and consumes a large amount of medical expenses. This paper was to review the establishment and evaluation methods of animal models of emphysema or COPD, and put forward some new ideas on animal selection, method of modeling, and model evaluation.

DATA SOURCES

The author retrieved information from the PubMed database up to July 2019, using various combinations of search terms, including emphysema, model, and animal.

STUDY SELECTION

Original articles, reviews, and other articles were searched and reviewed for animal models of emphysema.

RESULTS

This review summarized animal models of emphysema from the perspectives of animal selection, emphysema mechanism, modeling method and model evaluation, and found that passive smoking is the classic method for developing animal model of emphysema, mice are more suitable for experimental study on emphysema. Compared with pulmonary function indicators, airway inflammation indicators and oxidative stress indicators, pathomorphological indicators of lung tissue are the most important parameters for evaluating the establishment of the animal model of emphysema.

CONCLUSIONS

Mice model induced by passive smoking is the classic animal model of emphysema. Pathomorphological indicators are the most important parameters for evaluating the establishment of the animal model of emphysema.

Site-Specific DC Surface Signatures Influence CD4+ T Cell Co-stimulation and Lung-Homing

Dendritic cells (DCs) that drain the gut and skin are known to favor the establishment of T cell populations that home to the original site of DC-antigen (Ag) encounter by providing soluble “imprinting” signals to T cells in the lymph node (LN). To study the induction of lung T cell-trafficking, we used a protein-adjuvant murine intranasal and intramuscular immunization model to compare in vivo-activated Ag⁺ DCs in the lung and muscle-draining LNs. Higher frequencies of Ag⁺ CD11b⁺ DCs were observed in lung-draining mediastinal LNs (MedLN) compared to muscle-draining inguinal LNs (ILN). Ag⁺ CD11b⁺ MedLN DCs were qualitatively superior at priming CD4⁺ T cells, which then expressed CD49a and CXCR3, and preferentially trafficked into the lung parenchyma. CD11b⁺ DCs from the MedLN expressed higher levels of surface podoplanin, Trem4, GL7, and the known co-stimulatory molecules CD80, CD86, and CD24. Blockade of specific MedLN DC molecules or the use of sorted DC and T cell co-cultures demonstrated that DC surface phenotype influences the ability to prime T cells that then home to the lung. Thus, the density of dLN Ag⁺ DCs, and DC surface molecule signatures are factors that can influence the output and differentiation of lung-homing CD4⁺ T cells.

The early detection of asthma based on blood gene expression

Asthma is a complex heterogeneous disorder with hereditary tendency and the most widely used therapy is inhalation of anti-inflammatory corticosteroids. But it has systemic side effects. If the chronic inflammation can be detected in early stage, the dosage of corticosteroids will be low and the side effects can be avoided. Therefore, to discover the early stage blood biomarkers for asthma, we analyzed the gene expression profiles in the blood of 77 moderate asthma patients and 87 healthy controls. With advanced feature selection methods, minimal Redundancy Maximal Relevance and Incremental Feature Selection, we identified 31 genes, such as MYD88, ZFP36, CCR3 and CYP3A5, as the optimal asthma biomarker. The sensitivity, specificity and accuracy of the 31-gene Support Vector Machine predictor evaluated with Leave-One-Out Cross Validation were 0.870, 0.816 and 0.841, respectively. Through literature survey, many biomarker genes have asthma associated functions. Our results not only provided the easy-to-apply blood gene expression biomarkers for early detection of asthma, but also an explainable qualitative model with biological significance.

Cigarette smoke exposure worsens acute lung injury in antibiotic-treated bacterial pneumonia in mice

Evidence is accumulating that exposure to cigarette smoke (CS) increases the risk of developing acute respiratory distress syndrome (ARDS). Streptococcus pneumoniae is the most common cause of bacterial pneumonia, which in turn is the leading cause of ARDS. Chronic smokers have increased rates of pneumococcal colonization and develop more severe pneumococcal pneumonia than nonsmokers; yet mechanistic connections between CS exposure, bacterial pneumonia, and ARDS pathogenesis remain relatively unexplored. We exposed mice to 3 wk of moderate whole body CS or air, followed by intranasal inoculation with an invasive serotype of S. pneumoniae. CS exposure alone caused no detectable lung injury or bronchoalveolar lavage (BAL) inflammation. During pneumococcal infection, CS-exposed mice had greater survival than air-exposed mice, in association with reduced systemic spread of bacteria from the lungs. However, when mice were treated with antibiotics after infection to improve clinical relevance, the survival benefit was lost, and CS-exposed mice had more pulmonary edema, increased numbers of BAL monocytes, and elevated monocyte and lymphocyte chemokines. CS-exposed antibiotic-treated mice also had higher serum surfactant protein D and angiopoietin-2, consistent with more severe lung epithelial and endothelial injury. The results indicate that acute CS exposure enhances the recruitment of immune cells to the lung during bacterial pneumonia, an effect that may provide microbiological benefit but simultaneously exposes the mice to more severe inflammatory lung injury. The inclusion of antibiotic treatment in preclinical studies of acute lung injury in bacterial pneumonia may enhance clinical relevance, particularly for future studies of current or emerging tobacco products.

Clusterization of patients with idiopathic pulmonary fibrosis with chemokine receptors: a possible role in the diagnostic work-up of idiopathic pulmonary fibrosis?

Background and objective: Idiopathic pulmonary fibrosis (IPF) is a chronic and irreversible interstitial lung disease whose diagnosis often requires surgical lung biopsies (SLB) in cases without consistent radiological findings. We previously published that the expression of the chemokine receptors CXCR3 and CCR4 on T cells is significantly different in bronchoalveolar lavage (BAL) of IPF patients from other interstitial lung diseases. The aim of the study was to evaluate cut-off values of CXCR3 and CCR4 receptors expressed on bronchoalveolar lavage (BAL) and peripheral blood (PB) T cells useful for a differential diagnosis. Methods: Ninety-three patients were enrolled: 35 IPF, 36 interstitial lung diseases (nIPF) and 22 sarcoidosis. CXCR3 and CCR4 were evaluated on BAL and PB T lymphocytes with flow cytometry. Results: Among PB and BAL variables considered, the values of the ratio of BAL and PB CXCR3 on CD4 cells were clustered in the most informative way to obtain a classification rule for the diagnosis of patients without steroid therapy (n = 66/93). Patients with a CXCR3 ratio BAL/PB on CD4 T cells lower or equal than 1.43 were assigned to the IPF group with sensitivity = 0.87 and specificity = 0.90. All the other variables considered showed lower sensitivity and specificity in discriminating IPF patients. Conclusions: The evaluation of chemokine receptors on BAL and PB T lymphocytes could aid to discriminate IPF in subjects without steroid therapy, particularly in those patients with a high-resolution computed tomography (HRCT) non typical for Usual Interstitial Pneumonia (UIP). (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 35-43).

CXCR3+ monocytes/macrophages are required for establishment of pulmonary metastases

We present a new foundational role for CXCR3⁺ monocytes/macrophages in the process of tumor engraftment in the lung. CXCR3 is associated with monocytic and lymphocytic infiltration of inflamed or tumor-bearing lung. Although the requirement for tumor-expressed CXCR3 in metastatic engraftment has been demonstrated, the role of monocyte-expressed CXCR3 had not been appreciated. In a murine model of metastatic-like melanoma, engraftment was coordinate with CXCR3⁺ monocyte/macrophage accumulation in the lungs and was sensitive to pharmacologic inhibition of CXCR3 signaling. Tumor engraftment to lung was impaired in CXCR3^−/− mice, and transient reconstitution with circulating CXCR3-replete monocytes was sufficient to restore engraftment. These data illustrate the paradoxical pro-tumor role for CXCR3 in lung immunobiology wherein the CXCR3 axis drives both the anti-tumor effector cell chemoattraction and pro-tumor infiltration of the lungs and suggests a potential therapeutic target for lung-tropic metastasizing cancers.

Regulatory role of CCL5 (rs2280789) and CXCL10 (rs56061981) gene polymorphisms on intracellular CCL5 and CXCL10 expression in pulmonary tuberculosis

Genetic variations in chemokine genes influence the chemoattractive properties of T cells which may be associated with outcome of infections. In present study, we have investigated the regulatory role played by In1.1T/C (rs2280789) polymorphism of CCL5 and -135G/A (rs56061981) polymorphism of CXCL10 gene on intracellular CCL5 and CXCL10 expression in T cells. Whole blood cell cultures were stimulated with culture filtrate antigen (CFA) and infected with live M. tuberculosis were used for intracellular CCL5 and CXCL10 expression using flow cytometry. Genotyping was performed using polymerase chain reaction based restriction fragment length polymorphism (PCR-RFLP). Significantly higher expression of CCL5 expressing CD3+ and CD3+ CD8+ T cells were observed in HCs with In1.1TT genotype compared to C allele carrier (TT+TC) under unstimulated and CFA induced cultures (p<0.05). In -135G/A (rs56061981) polymorphism, PTB patients with GG genotype showed a significantly decreased expression of CD3+ CXCL10+ and CD3+ CD4+ CXCL10+ T cells compared to A allele carrier (GA+AA) under unstimulated, CFA induced and M. tuberculosis infected cultures (P<0.05). The present study suggest that TT genotype of CCL5 In1.1T/C (rs2280789) polymorphism play an important role to increased CCL5 expression in T cell which may enhanced Th1 immunity and help in protection against tuberculosis. The study also suggests GG genotype of CXCL10 -135G/A (rs56061981) polymorphism decreased CXCL10 expression in T cells which may have defective recruitment of mononuclear cells at the site of infection as well granuloma formation and in turn contribute to progression of TB.

CXCR3 May Help Regulate the Inflammatory Response in Acute Lung Injury via a Pathway Modulated by IL-10 Secreted by CD8 + CD122+ Regulatory T Cells

The aim of this study is to investigate the role of CXCR3 and IL-10 in lipopolysaccharide (LPS)-induced acute lung injury (ALI). ALI was induced by LPS injection (10 mg/kg) via the tail vein in C57BL/6 mice. Mice were sacrificed after 2 or 12 h to examine the levels of inflammatory cytokines in bronchoalveolar lavage fluid (BALF) and histopathologic assessments. At 12 h after LPS injection, mice exhibited more severe lung infiltration by CD8+ T cell and less infiltration by CD8+CD122+ regulatory T cells than at 2 h after LPS challenge or in the control (mice not exposed to LPS). At 12 h, IFN-γ, CXCR3, and CXCL10 were significantly higher in the lungs. IL-10 in the lungs was significantly lower. CXCR3 may help to recruit CD8+ T cells and promotes IFN-γ and CXCL10 release. Such effects could be inhibited by IL-10 secreted by CD8+CD122+ regulatory T cells.

Leukocyte-borne α(1,3)-fucose is a negative regulator of β2-integrin-dependent recruitment in lung inflammation

Leukocyte recruitment in inflammation is a multistep, sequential cascade where the initial step is the selectin-dependent tethering, followed by the formation of firmer integrin-mediated adhesive forces leading to extravasation. The α(1,3)-fucose-containing sialyl-Lewis X (sLe^X) is the archetypical ligand on leukocyte surfaces mediating selectin interactions. Canonically, disruption of α(1,3)-fucose formation ablates selectin-mediated adhesion, dramatically reducing trafficking. We report a paradoxical response to α(1,3)-fucose deficiency in which the loss exacerbated rather than attenuated leukocyte recruitment in a murine model of acute airway inflammation. The architecture of the capillary-dominated vasculature in the lung minimized the importance of the selectin dependent step, and we observed that α(1,3)-fucose deficiency augmented CXCR2-mediated Rap1-GTP signaling to enhance the β₂-integrin-ICAM-1-binding axis. The data disclose a previously unknown function for α(1,3)-fucose, in which this structure negatively regulates the integrin activation step in leukocyte recruitment.

Gremlin-1 Overexpression in Mouse Lung Reduces Silica-Induced Lymphocyte Recruitment - A Link to Idiopathic Pulmonary Fibrosis through Negative Correlation with CXCL10 Chemokine

Idiopathic pulmonary fibrosis (IPF) is characterized by activation and injury of epithelial cells, the accumulation of connective tissue and changes in the inflammatory microenvironment. The bone morphogenetic protein (BMP) inhibitor protein gremlin-1 is associated with the progression of fibrosis both in human and mouse lung. We generated a transgenic mouse model expressing gremlin-1 in type II lung epithelial cells using the surfactant protein C (SPC) promoter and the Cre-LoxP system. Gremlin-1 protein expression was detected specifically in the lung after birth and did not result in any signs of respiratory insufficiency. Exposure to silicon dioxide resulted in reduced amounts of lymphocyte aggregates in transgenic lungs while no alteration in the fibrotic response was observed. Microarray gene expression profiling and analyses of bronchoalveolar lavage fluid cytokines indicated a reduced lymphocytic response and a downregulation of interferon-induced gene program. Consistent with reduced Th1 response, there was a downregulation of the mRNA and protein expression of the anti-fibrotic chemokine CXCL10, which has been linked to IPF. In human IPF patient samples we also established a strong negative correlation in the mRNA expression levels of gremlin-1 and CXCL10. Our results suggest that in addition to regulation of epithelial-mesenchymal crosstalk during tissue injury, gremlin-1 modulates inflammatory cell recruitment and anti-fibrotic chemokine production in the lung.

Interleukin-22 exacerbates airway inflammation induced by short-term exposure to cigarette smoke in mice

AIM

Interleukin-22 (IL-22) exhibits both proinflammatory and anti-inflammatory properties in various biological processes. In this study we explored the effects of exogenous recombinant IL-22 (rIL-22) on cigarette smoke (CS)-induced airway inflammation in mice.

METHODS

Male C57BL/6 mice were divided into groups: (1) CS group exposed to tobacco smoke for 3 consecutive days, (2) rIL-22 group received rIL-22 (100 mg/kg, ip), and (3) CS plus rIL-22 group, received rIL-22 (100 mg/kg, ip) before the CS exposure. The airway resistance (Rn), lung morphology, inflammatory cells in the airways, and inflammatory cytokines and CXCR3 ligands in both bronchoalveolar lavage (BAL) fluids and lung tissues were analyzed.

RESULTS

CS alone significantly elevated IL-22 level in the BAL fluid. Both CS and rIL-22 significantly augmented airway resistance, an influx of inflammatory cells into the airways and lung parenchyma, and significantly elevated levels of pro-inflammatory cytokines (TGFβ1 and IL-17A) and CXCR3 chemokines (particularly CXCL10) at the mRNA and/or protein levels. Furthermore, the effects of rIL-22 on airway resistance and inflammation were synergistic with those of CS, as demonstrated by a further increased Rn value, infiltration of greater numbers of inflammatory cells into the lung, higher levels of inflammatory cytokines and chemokines, and more severe pathological changes in CS plus rIL-22 group as compared to those in CS group.

CONCLUSION

Exogenous rIL-22 exacerbates the airway inflammatory responses to CS exposure in part by inducing expression of several proinflammatory cytokines and CXCR3 ligands.

Toxicological in vitro and subchronic evaluation of LASSBio-596

LASSBio-596, 2-[4-(1,4-tiazinan-4-ylsulfonyl) phenylcarbamoyl] benzoic acid, is an achiral compound containing a subunit carboxylic amide, was capable of preventing induced mechanical and morphological changes in the lungs that commonly caused the onset of asthma. Previous studies to determine the acute toxicity of oral LASSBio-596 at dose of 2000mg/kg caused no deaths in any of the tested animals. To further evaluate the safety of LASSBio-596, in vitro and in vivo tests were carried out. Regarding to in vitro test were used renal, hepatic, pulmonary, cardiac, neurologic and intestinal cell lines. They were evaluated using neutral red (NR) and [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assays. Micronuclei also was performed. Concerning to in vivo was performed subchronic on Wistar rats at doses of 10, 50, and 250mg/kg and zebrafish test. The in vitro tests results showed the safety of LASSBio-596. However, subchronic toxicity study results revealed changes in the blood parameters of amylase, alanine aminotransferase (ALT), aspartate aminotransferase (AST), glucose and creatine kinase (CK) which is used for cardiotoxicity evaluation, although, did not identify any histopathological alterations. However, zebrafish test demonstrated cardiac damage. It was impossible to estimate the no-observed-adverse-effect-levels and lowest observed-adverse-effect level due to the presence of cardiotoxicity in all tested doses.

Cryptococcus gattii infection dampens Th1 and Th17 responses by attenuating dendritic cell function and pulmonary chemokine expression in the immunocompetent hosts

Cryptococcal infections are primarily caused by two related fungal species: Cryptococcus neoformans and Cryptococcus gattii. It is well known that C. neoformans generally affects immunocompromised hosts; however, C. gattii infection can cause diseases in not only immunocompromised hosts but also immunocompetent individuals. While recent studies suggest that C. gattii infection could dampen pulmonary neutrophil recruitment and inflammatory cytokine production in immunocompetent hosts, the impact of C. gattii infection on the development of their adaptive T helper cell immune response has not been addressed. Here, we report that C. neoformans infection with highly virulent and less virulent strains preferentially induced pulmonary Th1 and Th17 immune responses in the host, respectively. However, fewer pulmonary Th1 and Th17 cells could be detected in mice infected with C. gattii strains. Notably, dendritic cells (DC) in mice infected with C. gattii expressed much lower levels of surface MHC-II and Il12 or Il23 transcripts and failed to induce effective Th1 and Th17 differentiation in vitro. Furthermore, the expression levels of Ip10 and Cxcl9 transcripts, encoding Th1-attracting chemokines, were significantly reduced in the lungs of mice infected with the highly virulent C. gattii strain. Thus, our data suggest that C. gattii infection dampens the DC-mediated effective Th1/Th17 immune responses and downregulates the pulmonary chemokine expression, thus resulting in the inability to mount protective immunity in immunocompetent hosts.

Animal models of asthma: reprise or reboot?

Animal models of disease represent the pinnacle of hierarchical research efforts to validate targets and compounds for therapeutic intervention. Yet models of asthma, particularly in the mouse, which, for practical reasons, has become the sine qua non of asthma research, have been a bone of contention for decades. With barely a nod to their limitations and an extensive history of translational failures, they continue to be used for target identification and to justify the clinical evaluation of new compounds. Recent improvements - including sensitization directly to the airways; use of more relevant allergens; development of a chronic rather than short-term condition; utilization of techniques to measure lung function beyond uninterpretable measures of airway hyperresponsiveness - are laudable but cannot bridge the chasm between the models and the myriad complexities of the human disorder and multiple asthma endophenotypes. While further model developments are necessary, including recognition of key environmental factors beyond allergens, the judicious integration with newer ex vivo and in vitro techniques, including human precision-cut lung slices, reprograming of patient-derived induced pluripotent stem cells and fibroblasts to epithelial and smooth muscle cells, and use of other clinical samples to create a more holistic depiction of activities, might improve their translational success.

Higher serum CCL17 may be a promising predictor of acute exacerbations in chronic hypersensitivity pneumonitis

Background

Recent research has suggested that the Th1 and Th2 chemokine/cytokine axis contributes to the development of chronic hypersensitivity pneumonitis (HP). Acute exacerbations (AE) are significant factors in the prognosis of chronic HP. Little is known, however, about these biomarkers in association with AE in chronic HP patients.

Methods

Fifty-six patients with chronic HP were evaluated, including 14 patients during episodes of AE. Th1 mediators (C-X-C chemokine ligand [CXCL]10 and interferon [IFN]-γ), Th2 mediators (C-C chemokine ligand [CCL]17, interleukin-4, and interleukin-13), and pro-fibrotic mediator (transforming growth factor [TGF]-β) were measured to evaluate the mediators as predictors of AE. C-C chemokine receptor (CCR)4 (receptor for CCL17)-positive lymphocytes were quantified in lung specimens.

Results

Serum CCL17 levels at baseline independently predicted the first episode of AE (HR, 72.0; 95% CI, 5.03-1030.23; p = 0.002). AE was significantly more frequent in the higher-CCL17 group (≥285 pg/ml) than in the lower-CCL17 group (<285 pg/ml) (log-rank test, p = 0.0006; 1-year incidence: higher CCL17 vs. lower CCL17, 14.3% vs. 0.0%). Serum CCL17 levels and CCR4-positive cells during episodes of AE were increased from the baseline (p = 0.01 and 0.031).

Conclusions

Higher serum concentrations of CCL17 at baseline may be predictive of AE in patients with chronic HP, and CCL17 may contribute to the pathology of AE by inducing the accumulation of CCR4-positive lymphocytes in the lungs.

Impact of antiretroviral therapy on lung immunology and inflammation

Human immunodeficiency virus (HIV) infection causes profound changes in the lung compartment characterized by macrophage and lymphocyte activation, secretion of proinflammatory cytokines and chemokines, and accumulation of CD8 T cells in the alveolar space, leading to lymphocytic alveolitis. Because many of the changes seen in the lung can be attributed to the direct effect of HIV on immune cells, therapy to reduce the HIV burden should have significant beneficial effects. Indeed, antiretroviral therapy rapidly reduces the viral burden in the lung, number of CD8 T cells in the alveolar space, and amount of proinflammatory cytokines and chemokines in bronchoalveolar lavage.

Smoking decreases the response of human lung macrophages to double-stranded RNA by reducing TLR3 expression

BACKGROUND

Cigarette smoking is associated with increased frequency and duration of viral respiratory infections, but the underlying mechanisms are incompletely defined. We investigated whether smoking reduces expression by human lung macrophages (Mø) of receptors for viral nucleic acids and, if so, the effect on CXCL10 production.

METHODS

We collected alveolar macrophages (AMø) by bronchoalveolar lavage of radiographically-normal lungs of subjects undergoing bronchoscopies for solitary nodules (n = 16) and of volunteers who were current or former smokers (n = 7) or never-smokers (n = 13). We measured expression of mRNA transcripts for viral nucleic acid receptors by real-time PCR in those AMø and in the human Mø cell line THP-1 following phorbol myristate acetate/vitamin D3 differentiation and exposure to cigarette smoke extract, and determined TLR3 protein expression using flow cytometry and immunohistochemistry. We also used flow cytometry to examine TLR3 expression in total lung Mø from subjects undergoing clinically-indicated lung resections (n = 25). Of these, seven had normal FEV1 and FEV1/FVC ratio (three former smokers, four current smokers); the remaining 18 subjects (14 former smokers; four current smokers) had COPD of GOLD stages I-IV. We measured AMø production of CXCL10 in response to stimulation with the dsRNA analogue poly(I:C) using Luminex assay.

RESULTS

Relative to AMø of never-smokers, AMø of smokers demonstrated reduced protein expression of TLR3 and decreased mRNA for TLR3 but not TLR7, TLR8, TLR9, RIG-I, MDA-5 or PKR. Identical changes in TLR3 gene expression were induced in differentiated THP-1 cells exposed to cigarette smoke-extract in vitro for 4 hours. Among total lung Mø, the percentage of TLR3-positive cells correlated inversely with active smoking but not with COPD diagnosis, FEV1% predicted, sex, age or pack-years. Compared to AMø of never-smokers, poly(I:C)-stimulated production of CXCL10 was significantly reduced in AMø of smokers.

CONCLUSIONS

Active smoking, independent of COPD stage or smoking duration, reduces both the percent of human lung Mø expressing TLR3, and dsRNA-induced CXCL10 production, without altering other endosomal or cytoplasmic receptors for microbial nucleic acids. This effect provides one possible mechanism for increased frequency and duration of viral lower respiratory tract infections in smokers.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00281190, NCT00281203 and NCT00281229.

Chemokine profiles in blood associated with delayed asthmatic response to allergen challenge

BACKGROUND

Patients with bronchial asthma having been challenged with allergen develop various types of asthmatic response, such as immediate (IAR), late (LAR) or delayed (DYAR) response, due to different immunologic mechanisms. The DYAR, beginning 26-32 h, reaching maximum between 32 and 48 h and resolving within 56 h after the challenge, differs from IAR and LAR in clinical and immunologic features.

OBJECTIVES

To investigate the changes in the serum concentrations of chemokines associated with the isolated form of DYAR.

METHODS

In 22 patients the repeated DYAR (p < 0.001) was supplemented with recording of blood cell counts and serum concentrations of chemokines before, and up to 72 h after the bronchial challenge by means of enzyme-linked immunoassay, (ELISA).

RESULTS

The DYAR was associated with (a) significantly increased serum concentrations (p < 0.05) of CCL 2, CCL 3, CCL 4, CCL 7, CCL 20, CXCL 1, CXCL 8, CXCL 9, CXCL 10 and CXCL 11, and (b) significantly decreased serum concentrations, (p < 0.05) of CCL 5, CCL 11, CCL 17, CCL 22, CCL 24 and CCL 26, as compared with their pre-challenge as well as the PBS control values. No significant chemokine changes were recorded during the PBS controls (p > 0.1).

CONCLUSIONS

These results, together with changes in the blood cell counts, provide evidence for an involvement of activated Th(1), cells and NK cells (CCL-2, -3, -4, -20, CXCL-9,-10,-11), neutrophils (CCL-20, CXCL-1,-8) and monocytes (CCL-2,-3,-4, -7, CXCL-10), upon co-operation of other cell types, such as epithelial, endothelial and dendritic cells, in the immunologic mechanism(s) underlying the DYAR.

Improvement of ventilator-induced lung injury by IPS cell-derived conditioned medium via inhibition of PI3K/Akt pathway and IP-10-dependent paracrine regulation

Mechanical ventilation in patients may increase the risk of an acute lung injury (ALI), termed ventilator-induced lung injury (VILI). Induced pluripotent stem cells (iPSCs) have previously been shown to improve tissue repair in different disease models, including ALI. However, the therapeutic efficacy of iPSCs-derived conditioned medium (iPSC-CM) on ALI or VILI remains unknown. Here, we demonstrated that both iPSCs and iPSC-CM effectively decrease high-tidal-volume-induced VILI-related inflammatory processes and HMGB1 and PAI-1 production, predominantly through suppressing PI3K/Akt signaling. Notably, iPSC-CM suppressed production of macrophage inflammatory protein-2, malondialdehyde, and increased total glutathione content. Transmission electron microscopy revealed that iPSC-CM potentially restored the bronchial microstructure. This iPSC-CM efficacy could be mimicked by PI3K inhibitor LY294002 or Akt heterozygous knockout, and either treatment showed no further improvement on VILI in iPSC-CM recipients. Furthermore, iPSC-CM increased interferon gamma-induced protein 10 (IP-10) production in injured lungs. Administration of IP-10-neutralizing antibodies increased neutrophil infiltration, impaired lung oxygenation and deteriorated the protective effects mediated by iPSC-CM. Our data provide a preclinical indication regarding the therapeutic potential of iPSC-CM in VILI and suggest that inhibiting PI3K/Akt pathway or increasing IP-10 is a prospective diagnostic and therapeutic target for VILI patients.

The Tumor-Promoting Flow of Cells Into, Within and Out of the Tumor Site: Regulation by the Inflammatory Axis of TNFα and Chemokines

Tumors are dynamic organs, in which active processes of cell motility affect disease course by regulating the composition of cells at the tumor site. While sub-populations of tumor-promoting leukocytes are recruited inward and endothelial cell migration stands in the basis of vascular branching throughout the tumor, cancer cells make their way out of the primary site towards specific metastatic sites. This review describes the independent and cross-regulatory roles of inflammatory chemokines and of the inflammatory cytokine tumor necrosis factor α (TNFα) in determining cell motility processes that eventually have profound effects on tumor growth and metastasis. First, the effects of inflammatory chemokines such as CCL2 (MCP-1), CCL5 (RANTES) and CXCL8 (IL-8) are described, regulating the inward flow of leukocyte sub-populations with pro-tumoral activities, such as tumor-associated macrophages (TAM), myeloid-derived suppressor cells (MDSC), tumor-associated neutrophils (TAN), Th17 cells and Tregs. Then, the ability of inflammatory chemokines to induce endothelial cell migration, sprouting and tube formation is discussed, with its implications on tumor angiogenesis. This part is followed by an in depth description of the manners by which TNFα potentiates the above activities of the inflammatory chemokines, alongside with its ability to directly induce migratory processes in the tumor cells thus promoting metastasis. Note worthy is the ability of TNFα to induce in the tumor cells the important process of epithelial-to-mesenchymal transition (EMT). Emphasis is given to the ability of TNFα to establish an inflammatory network with the chemokines, and in parallel to form a cell re-modeling network together with transforming growth factor β (TGFβ). The review concludes by discussing the implications of such networks on disease course, and on the future design of therapeutic measures in cancer.

CARMA1 is necessary for optimal T cell responses in a murine model of allergic asthma

CARMA1 is a lymphocyte-specific scaffold protein necessary for T cell activation. Deletion of CARMA1 prevents the development of allergic airway inflammation in a mouse model of asthma due to a defect in naive T cell activation. However, it is unknown if CARMA1 is important for effector and memory T cell responses after the initial establishment of inflammation, findings that would be more relevant to asthma therapies targeted to CARMA1. In the current study, we sought to elucidate the role of CARMA1 in T cells that have been previously activated. Using mice in which floxed CARMA1 exons can be selectively deleted in T cells by OX40-driven Cre recombinase (OX40(+/Cre)CARMA1(F/F)), we report that CD4(+) T cells from these mice have impaired T cell reactivation responses and NF-κB signaling in vitro. Furthermore, in an in vivo recall model of allergic airway inflammation that is dependent on memory T cell function, OX40(+/Cre)CARMA1(F/F) mice have attenuated eosinophilic airway inflammation, T cell activation, and Th2 cytokine production. Using MHC class II tetramers, we demonstrate that the development and maintenance of Ag-specific memory T cells is not affected in OX40(+/Cre)CARMA1(F/F) mice. In addition, adoptive transfer of Th2-polarized OX40(+/Cre)CARMA1(F/F) Ag-specific CD4(+) T cells into wild-type mice induces markedly less airway inflammation in response to Ag challenge than transfer of wild-type Th2 cells. These data demonstrate a novel role for CARMA1 in effector and memory T cell responses and suggest that therapeutic strategies targeting CARMA1 could help treat chronic inflammatory disorders such as asthma.

Attenuation of antigen-induced airway hyperresponsiveness and inflammation in CXCR3 knockout mice

Background

CD8+ T cells participate in airway hyperresponsiveness (AHR) and allergic pulmonary inflammation that are characteristics of asthma. CXCL10 by binding to CXCR3 expressed preferentially on activated CD8+ T cells, attracts T cells homing to the lung. We studied the contribution and limitation of CXCR3 to AHR and airway inflammation induced by ovalbumin (OVA) using CXCR3 knockout (KO) mice.

Methods

Mice were sensitized and challenged with OVA. Lung histopathological changes, AHR, cellular composition and levels of inflammatory mediators in bronchoalveolar lavage (BAL) fluid, and lungs at mRNA and protein levels, were compared between CXCR3 KO mice and wild type (WT) mice.

Results

Compared with the WT controls, CXCR3 KO mice showed less OVA-induced infiltration of inflammatory cells around airways and vessels, and less mucus production. CXCR3 KO mice failed to develop significant AHR. They also demonstrated significantly fewer CD8+ T and CD4+ T cells in BAL fluid, lower levels of TNFα and IL-4 in lung tissue measured by real-time RT-PCR and in BAL fluid by ELISA, with significant elevation of IFNγ mRNA and protein expression levels.

Conclusions

We conclude that CXCR3 is crucial for AHR and airway inflammation by promoting recruitment of more CD8+ T cells, as well as CD4+ T cells, and initiating release of proinflammatory mediators following OVA sensitization and challenge. CXCR3 may represent a novel therapeutic target for asthma.

Antiasthmatic effects of Gleditsia sinensis in an ovalbumin-induced murine model of asthma

This study evaluated the antiasthmatic effects of Gleditsia sinensis ethanolic extract (GSEE) and its underlying mechanisms, using an in vivo murine model of asthma. Female BALB/c mice were sensitized, challenged with ovalbumin, and then examined for asthmatic reactions. The results showed that GSEE exerted profound inhibitory effects on the accumulation of eosinophils in the airways and reduced the levels of interleukin (IL)-4 and IL-5 in bronchoalveolar lavage fluid (BALF) and immunoglobulin E (IgE) in BALF and plasma. Gleditsia sinensis ethanolic extract also suppressed the production of reactive oxygen species in BALF and inflammatory infiltration, in a dose-dependent manner, and it inhibited goblet-cell hyperplasia in lung tissue. Thus, GSEE shows antiasthmatic effects in a murine model of allergic asthma, which appeared to be mediated partially by the reduction of oxidative stress and airway inflammation. These results indicate that GSEE could be an effective novel therapeutic agent for the treatment of allergic asthma.

The prevalence and meaning of eosinophilia in renal diseases on a nephrology consultation service

BACKGROUND

In recent years, we have come to understand that the eosinophil is more than the end point in clearance of parasitic infection or a maladaptive response to asthma and allergic reactions. Since eosinophilia has been reported to be common in renal diseases, we thought that an evaluation of the associations of eosinophilia on a renal consultation service would add some value to the understanding of their role in renal disease.

METHODS

This was a prospective cross-sectional study of 1339 consecutive patients referred to the nephrology service after hospitalization who were evaluated for the relationship of the amount of serum eosinophils to their diagnosis, gender, age and the presence of autoimmune disease, cancer, infection, liver disease, pleural effusions, allergies and use of prednisone, beta-blockers or beta agonists, in addition to the total white blood count, urine protein, serum concentration creatinine and phosphorus levels and estimated glomerular filtration rate.

RESULTS

The presence of vascular disease correlated the most strongly with increased eosinophil count (partial correlation coefficient, r = 0.18, P = 0.006), followed by pleural effusions (r = 0.17, P = 0.001), while total white cell count (r = -0.18, P = 0.008) and administration of beta-blockers (r = -0.13, P = 0.047) demonstrated significant inverse correlations and the presence of autoimmune disease, cancer, allergies, proteinuria and serum phosphorus concentration demonstrated no significant correlation.

CONCLUSION

There are multiple associations with increased eosinophil counts in patients seen on a nephrology consultant service; however, their presence appears less often in association with allergies or uremia and more often with vascular disease.

Anti-asthmatic effects of Angelica dahurica against ovalbumin-induced airway inflammation via upregulation of heme oxygenase-1

Asthma is a chronic immune inflammatory disease characterized by variable airflow obstruction. The present study was undertaken to assess the effects of an Angelica dahurica Bentham et Hooker ethanolic extract (AD) on airway inflammation in an ovalbumin (OVA)-induced airway inflammation model. Mice that received AD displayed significantly lower airway eosinophilia, cytokine levels, including interleukin (IL)-4, IL-5, and tumor necrosis factor (TNF)-alpha levels, mucus production and immunoglobulin (Ig)E, compared with OVA-induced mice. In our experiments, AD treatment reduced airway inflammation and suppressed oxidative stress in the OVA-induced asthma model, partly via induction of heme oxygenase (HO)-1. The effects of AD on OVA-induced HO-1 induction were partially reversed by the HO-1 inhibitor, tin protoporphyrin (SnPP). Our results clearly indicate that AD is a suppressor of airway allergic inflammation, and may thus be effectively used as an anti-inflammatory drug in the treatment of asthma.

Plasma brain-derived neurotrophic factor levels are associated with clinical severity in school age children with asthma

BACKGROUND

Asthma is characterized by chronic inflammation of the airways with significant changes in leucocyte trafficking, cellular activation and tissue remodelling. Brain-derived neurotrophic factor (BDNF) has been involved with asthma and allergic diseases but its role as a severity marker in paediatric asthma has not been clinically assessed.

OBJECTIVES

To evaluate plasma BDNF and inflammatory markers in order to address their relationships with disease severity in children (6-15 years) with controlled persistent asthma.

METHODS

Children with persistent asthma were selected and lung function and skin prick tests were performed in all patients. Plasma BDNF levels and various inflammatory markers (CCL3, CCL11, CCL22, CCL24, CXCL8, CXCL9, CXCL10, soluble TNF receptors) were assessed by ELISAs.

RESULTS

Subjects with moderate and severe asthma had higher BDNF levels than mild asthma and controls (P<0.001). The chemokines studied and soluble TNF receptors did not differ between the studied groups.

CONCLUSION AND CLINICAL RELEVANCE

Our results indicate BDNF as a potential biomarker for clinical severity in children with asthma.

Chemokine receptor CXCR3 is important for lung tissue damage and airway remodeling induced by short-term exposure to cigarette smoking in mice

AIM

To investigate the role of chemokine receptor CXCR3 in cigarette smoking (CS)-induced pulmonary damage.

METHODS

CXCR3 knockout (CXCR3-/-) mice were used. Differences in airspace enlargement, mRNA expression of matrix metalloproteinases (MMPs), transforming growth factor (TGF) beta1, CXCL10 in lung homogenates, and CXCL10 content in bronchoalveolar lavage (BAL) fluids and homogenates were compared between CXCR3-/- mice and wild-type (WT) mice three days after three-day CS exposures.

RESULTS

The linear intercept was significantly less in CXCR3-/- mice than in WT mice (30.1+/-0.9 microm vs 40.3+/-2.4 microm, P<0.01). Morphologically, collagen was deposited less around airways and vessels in CXCR3-/- mice. The lung hydroxyproline content was significantly lower in CXCR3-/- mice than in WT mice (6.0+/-1.0 microg/mL vs 12.0+/-1.6 microg/mL, P<0.05). Profoundly lower mRNA expression of MMP2, MMP12, TGF beta 1, and CXCL10 was seen in lung homogenates from CXCR3-/- mice. CXCL10 concentrations in BAL fluid and lung homogenates were significantly lower in CXCR3-/- mice than in WT mice (BAL fluid: 19.3+/-1.4 pg/mL vs 24.8+/-1.6 pg/mL, P<0.05; lung homogenates: 76.6+/-7.0 pg/mL vs 119.5+/-15.9 pg/mL, P<0.05).

CONCLUSION

CXCR3 is important in mediating lung tissue damage and airway remodeling following a short-term CS insult, possibly through up-regulation of CXCL10 and inducement of mRNA expression of MMPs. Targeting CXCR3 may be helpful for prevention of CS-induced pulmonary pathology.

Differential polarization of alveolar macrophages and bone marrow-derived monocytes following chemically and pathogen-induced chronic lung inflammation

Alveolar macrophages and BDMCs undergo sequential biochemical changes during the chronic inflammatory response to chemically induced lung carcinogenesis in mice. Herein, we examine two chronic lung inflammation models-repeated exposure to BHT and infection with Mycobacterium tuberculosis-to establish whether similar macrophage phenotype changes occur in non-neoplastic pulmonary disease. Exposure to BHT or M. tuberculosis results in pulmonary inflammation characterized by an influx of macrophages, followed by systemic effects on the BM and other organs. In both models, pulmonary IFN-gamma and IL-4 production coincided with altered polarization of alveolar macrophages. Soon after BHT administration or M. tuberculosis infection, IFN-gamma content in BALF increased, and BAL macrophages became classically (M1) polarized, as characterized by increased expression of iNOS. As inflammation progressed in both models, the amount of BALF IFN-gamma content and BAL macrophage iNOS expression decreased, and BALF IL-4 content and macrophage arginase I expression rose, indicating alternative/M2 polarization. Macrophages present in M. tuberculosis-induced granulomas remained M1-polarized, implying that these two pulmonary macrophage populations, alveolar and granuloma-associated, are exposed to different activating cytokines. BDMCs from BHT-treated mice displayed polarization profiles similar to alveolar macrophages, but BDMCs in M. tuberculosis-infected mice did not become polarized. Thus, only alveolar macrophages in these two models of chronic lung disease exhibit a similar progression of polarization changes; polarization of BDMCs was specific to BHT-induced pulmonary inflammation, and polarization of granuloma macrophages was specific to the M. tuberculosis infection.

Differential Th1/Th2 chemokine expression in interstitial pneumonia

BACKGROUND

T-helper (Th)-2 background in the lungs may favor the development of pulmonary fibrosis. We hypothesized that usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP), major pathologic patterns of chronic interstitial pneumonia, would have different expression profiles of TH1 and TH2 chemokines.

METHODS

Total RNA was isolated from lung tissues obtained by surgical biopsy (18 cases of UIP and 29 cases of NSIP). The expression of ligands for CXCR3 [TH1 cells chemoattractant: monokine induced by interferon (IFN)-gamma (MIG), IFN-gamma-inducible protein of 10 kD, and IFN-inducible T cell alpha chemoattractant] and ligands for CCR4 [TH2 cells chemoattractant: thymus- and activation-regulated chemokine and macrophage-derived chemokine (MDC)] were analyzed by real-time reverse transcriptase polymerase chain reaction.

RESULTS

MIG and IFNgamma-inducible protein of 10 kD expression were significantly higher in NSIP compared with UIP. MDC expression was increased in UIP compared with NSIP, although the difference was not significant. MIG/MDC is significantly elevated in NSIP but not UIP. Interestingly, MIG/MDC was significantly higher in NSIP group 3 (NSIP with extensive fibrosis) compared with UIP.

CONCLUSIONS

These results may indicate that these 2 diseases have a different pathophysiology. MIG/MDC may be a useful marker to distinguish these 2 diseases.

Involvement of sirtuin 1 in airway inflammation and hyperresponsiveness of allergic airway disease

BACKGROUND

Bronchial asthma is a chronic inflammatory disorder of the airways characterized by increased expression of multiple inflammatory genes. Acetylation of histones by histone acetyltransferases is associated with increased gene transcription, whereas hypoacetylation induced by histone deacetylases is associated with suppression of gene expression. Sirtuin 1 (SIRT1) is a member of the silent information regulator 2 family that belongs to class III histone deacetylase.

OBJECTIVE

This study aimed to investigate the role of SIRT1 and the related molecular mechanisms in the pathogenesis of allergic airway disease.

METHODS

By using a murine model of ovalbumin (OVA)-induced allergic airway disease and murine tracheal epithelial cells, this study investigated the involvement of SIRT1 and its signaling networks in allergic airway inflammation and hyperresponsiveness.

RESULTS

In this study with mice after inhalation of OVA, the increased levels of SIRT1, hypoxia-inducible factor 1alpha (HIF-1alpha), and vascular endothelial growth factor protein in the lungs after OVA inhalation were decreased substantially by the administration of a SIRT1 inhibitor, sirtinol. We also showed that the administration of sirtinol reduced significantly the increased numbers of inflammatory cells of the airways; airway hyperresponsiveness; increased levels of IL-4, IL-5, and IL-13; and increased vascular permeability in the lungs after OVA inhalation. In addition, we have found that inhibition of SIRT1 reduced OVA-induced upregulation of HIF-1alpha in airway epithelial cells.

CONCLUSIONS

These results indicate that inhibition of SIRT1 might attenuate antigen-induced airway inflammation and hyperresponsiveness through the modulation of vascular endothelial growth factor expression mediated by HIF-1alpha in mice.

Immune effects observed after the injection of plasmids coding for rainbow trout (Oncorhynchus mykiss) CK5B, CK6 and CK7A chemokines demonstrate their immunomodulatory capacity and reveal CK6 as a major interferon inducer

In the current study, we have determined the immune effects of the intramuscular injection of eukaryotic expression plasmids coding for rainbow trout (Oncorhynchus mykiss) CK5B, CK6 or CK7A CC chemokines (pCK5B, pCK6 and pCK7A) as a first step towards the establishment of their biological role. We have studied the levels of expression of several immune genes in the spleen and head kidney by real-time PCR in comparison to the levels observed in animals injected with the empty plasmid. Concerning the levels of expression of these CC chemokines and the CXC chemokine, interleukin 8 (IL-8), each plasmid induced up-regulation on expression levels of its coded chemokine in the head kidney and spleen, but also affected the expression of other chemokines. Both pCK6 and pCK7A induced the expression of the other two CC chemokines, while pCK5B induced CK7A but not CK6. Both pCK5B and pCK7A induced IL-8 as well. pCK6 was the only plasmid that induced IL-1beta in the head kidney, whereas in the spleen, this occurred only with pCK5B. Different effects on the head kidney and spleen were also visible for tumour necrosis factor alpha (TNF-alpha), since the three plasmids induced this cytokine in the head kidney, but only pCK5B and pCK6 in the spleen. Concerning the effects on type I interferon (IFN), again pCK6 induced the strongest enhancement in the head kidney, while in the spleen it was pCK5B. However, the levels of expression of the Mx gene, know to be induced by type I IFN correlated with the CK6-induced IFN levels in the head kidney, but not with the CK5B-induced IFN in head kidney or spleen, suggesting an inhibition of Mx mRNA levels independent of IFN due to CK5B. The clear effect of pCK6 on the levels of expression of IFN-gamma and its strong effects on type I IFN, in contrast with its recent adscription to the CCL17/22 group linked to Th2 responses, were verified by studying the in vitro effects of recombinant CK6 on head kidney leukocytes. Again in this case, recombinant CK6 strongly induced type I IFN, Mx and IFN-gamma to a lesser extent, revealing CK6 as a potent IFN inducer in contrast to its mammalian homologues. Finally, effects on major histocompatibility complex (MHC)-IIalpha, CD4 and CD8alpha expression demonstrate that the three chemokines are able to mobilize antigen-presenting cells, CD4(+) and CD8(+) lymphocytes.

Lymphocytes in the development of lung inflammation: a role for regulatory CD4+ T cells in indirect pulmonary lung injury

Although roles for myelocytes have been suggested in the pathophysiology of indirect acute lung injury (ALI not due to a direct insult to the lung), the contribution of various regulatory lymphoid subsets is unknown. We hypothesized a role for lymphocytes in this process. Using a sequential model of indirect ALI induced in mice by hemorrhagic shock followed 24 h later by polymicrobial sepsis; we observed a specific and nonredundant role for each lymphocyte subpopulation in indirect ALI pathophysiology. In particular, we showed that CD4(+) T cells are specifically recruited to the lung in a dendritic cell-independent but IL-16-dependent process and diminish neutrophil recruitment through increased IL-10 production. Most importantly, this appears to be mediated by the specific subpopulation of CD4(+)CD25(+)Foxp3(+) regulatory T cells. Although indirect ALI has constantly been described as a proinflammatory pathology mediated by cells of the innate immune system, we now demonstrate that cells of the adaptive immune response play a major role in its pathophysiology as well. Most importantly, we also describe for the first time the nature of the regulatory mechanisms activated in the lung during indirect ALI, with CD4(+) regulatory T cells being central to the control of neutrophil recruitment via increased IL-10 production.

Alcohol use disorder and perioperative immune dysfunction

The anesthesiological sequelae of long-term alcohol abuse include a three to fivefold increased risk of postoperative infection, prolonged intensive care unit stays and longer hospital stays. The cause of the higher infection rates is an altered immune response in long-term alcoholic patients. Preoperatively, the T helper cells 1 to T helper cells 2 ratio is depressed in long-term alcoholic patients and remains suppressed after surgery. The lower preoperative T helper cells 1 to T helper cells 2 ratio is predictive of later onset of infections. Postoperatively, the cytotoxic lymphocyte (Tc1/Tc2) ratio is decreased in long-term alcoholic patients and remains depressed for 5 days. The interleukin (IL)-6/IL-10 ratio and the lipopolysaccharide-stimulated interferon gamma/IL-10 ratio in whole blood cells are decreased after surgery in long-term alcoholic patients. Depressed Tc1/Tc2, IL-6/IL-10 and lipopolysaccharide-stimulated interferon gamma/IL-10 ratios in the postoperative period are predictive of subsequent postoperative infections. Perioperative interventions should aim to minimize dysregulation of the immune system.

Attenuation of acute lung inflammation induced by cigarette smoke in CXCR3 knockout mice

BACKGROUND

CD8+ T cells may participate in cigarette smoke (CS) induced-lung inflammation in mice. CXCL10/IP-10 (IFNgamma-inducible protein 10) and CXCL9/Mig (monokine induced by IFN-gamma) are up-regulated in CS-induced lung injury and may attract T-cell recruitment to the lung. These chemokines together with CXCL11/ITAC (IFN-inducible T-cell alpha chemoattractant) are ligands for the chemokine receptor CXCR3 which is preferentially expressed chiefly in activated CD8+ T cells. The purpose of this investigation was to study the contribution of CXCR3 to acute lung inflammation induced by CS using CXCR3 knockout (KO) mice.

METHODS

Mice (n = 8 per group) were placed in a closed plastic box connected to a smoke generator and were exposed whole body to the tobacco smoke of five cigarettes four times a day for three days. Lung pathological changes, expression of inflammatory mediators in bronchoalveolar lavage (BAL) fluid and lungs at mRNA and protein levels, and lung infiltration of CD8+ T cells were compared between CXCR3-/- mice and wild type (WT) mice.

RESULTS

Compared with the WT littermates, CXCR3 KO mice showed less CS-induced lung inflammation as evidenced by less infiltration of inflammatory cells in airways and lung tissue, particularly fewer CD8+ T cells, lower levels of IFNgamma and CXCR3 ligands (particularly CXCL10).

CONCLUSION

Our findings show that CXCR3 is important in promoting CD8+ T cell recruitment and in initiating IFNgamma and CXCL10 release following CS exposure. CXCR3 may represent a promising therapeutic target for acute lung inflammation induced by CS.