CCL22 and CCL17 in rat radiation pneumonitis and in human idiopathic pulmonary fibrosis

Chemokines and their receptors in the esophageal carcinoma tumor microenvironment: key factors for metastasis and progression

Esophageal carcinoma (ESCA) is a highly malignant tumor with the highest incidence in Eastern Asia. Although treatment modalities for ESCA have advanced in recent years, the overall prognosis remains poor, as most patients are diagnosed at an advanced stage of the disease. There is an urgent need to promote early screening for ESCA to increase survival rates and improve patient outcomes. The development of ESCA is closely linked to the complex tumor microenvironment (TME), where chemokines and their receptors play pivotal roles. Chemokines are a class of small-molecule, secreted proteins and constitute the largest family of cytokines. They not only directly regulate tumor growth and proliferation but also influence cell migration and localization through specific receptor interactions. Consequently, chemokines and their receptors affect tumor invasion and metastatic spread. Furthermore, chemokines regulate immune cells, including macrophages and regulatory T cells, within the TME. The recruitment of these immune cells further leads to immunosuppression, creating favorable conditions for tumor growth and metastasis. This review examines the impact of ESCA-associated chemokines and their receptors on ESCA, emphasizing their critical involvement in the ESCA TME.

Myeloid-Derived Suppressor Cell Accumulation Drives Intestinal Fibrosis through mCCL6/hCCL15 Chemokine-Mediated Fibroblast Activation

Intestinal fibrosis, a severe complication of Crohn's disease (CD), is linked to chronic inflammation, but the precise mechanism by which immune-driven intestinal inflammation leads to fibrosis development is not fully understood. This study investigates the role of myeloid-derived suppressor cells (MDSCs) in intestinal fibrosis in CD patients and a 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced mouse model. Elevated MDSCs are observed in inflamed intestinal tissues prior to fibrosis and their sustained presence in fibrotic tissues of both CD patients and murine models. Depletion of MDSCs significantly reduces fibrosis, highlighting their key role in the fibrotic process. Mechanistically, MDSC-derived mCCL6 activates fibroblasts via the CCR1-MAPK signaling, and interventions targeting this axis, including neutralizing antibodies, a CCR1 antagonist, or fibroblast-specific Ccr1 knockout mice reduce fibrosis. In CD patients with stenosis, human CCL15, analogous to mCCL6, is found to be elevated in MDSCs and activated fibroblasts. Additionally, CXCR2 and CCR2 ligands are identified as key mediators of MDSC recruitment in intestinal fibrosis. Blocking MDSC recruitment with CXCR2 and CCR2 antagonists alleviates intestinal fibrosis. These findings suggest that strategies targeting MDSC recruitment and mCCL6/hCCL15 signaling could offer therapeutic benefits for intestinal fibrosis.

TRAIL agonists rescue mice from radiation-induced lung, skin, or esophageal injury

Radiotherapy can be limited by pneumonitis, which is impacted by innate immunity, including pathways regulated by TRAIL death receptor DR5. We investigated whether DR5 agonists could rescue mice from toxic effects of radiation and found that 2 different agonists, parenteral PEGylated trimeric TRAIL (TLY012) and oral TRAIL-inducing compound (TIC10/ONC201), could reduce pneumonitis, alveolar wall thickness, and oxygen desaturation. Lung protection extended to late effects of radiation including less fibrosis at 22 weeks in TLY012-rescued survivors versus unrescued surviving irradiated mice. Wild-type orthotopic breast tumor-bearing mice receiving 20 Gy thoracic radiation were protected from pneumonitis with disappearance of tumors. At the molecular level, radioprotection appeared to be due to inhibition of CCL22, a macrophage-derived chemokine previously associated with radiation pneumonitis and pulmonary fibrosis. Treatment with anti-CCL22 reduced lung injury in vivo but less so than TLY012. Pneumonitis severity was worse in female versus male mice, and this was associated with increased expression of X-linked TLR7. Irradiated mice had reduced esophagitis characterized by reduced epithelial disruption and muscularis externa thickness following treatment with the ONC201 analog ONC212. The discovery that short-term treatment with TRAIL pathway agonists effectively rescues animals from pneumonitis, dermatitis, and esophagitis following high doses of thoracic radiation exposure has important translational implications.

The Chemokine System as a Key Regulator of Pulmonary Fibrosis: Converging Pathways in Human Idiopathic Pulmonary Fibrosis (IPF) and the Bleomycin-Induced Lung Fibrosis Model in Mice

Idiopathic pulmonary fibrosis (IPF) is a chronic and lethal interstitial lung disease (ILD) of unknown origin, characterized by limited treatment efficacy and a fibroproliferative nature. It is marked by excessive extracellular matrix deposition in the pulmonary parenchyma, leading to progressive lung volume decline and impaired gas exchange. The chemokine system, a network of proteins involved in cellular communication with diverse biological functions, plays a crucial role in various respiratory diseases. Chemokine receptors trigger the activation, proliferation, and migration of lung-resident cells, including pneumocytes, endothelial cells, alveolar macrophages, and fibroblasts. Around 50 chemokines can potentially interact with 20 receptors, expressed by both leukocytes and non-leukocytes such as tissue parenchyma cells, contributing to processes such as leukocyte mobilization from the bone marrow, recirculation through lymphoid organs, and tissue influx during inflammation or immune response. This narrative review explores the complexity of the chemokine system in the context of IPF and the bleomycin-induced lung fibrosis mouse model. The goal is to identify specific chemokines and receptors as potential therapeutic targets. Recent progress in understanding the role of the chemokine system during IPF, using experimental models and molecular diagnosis, underscores the complex nature of this system in the context of the disease. Despite advances in experimental models and molecular diagnostics, discovering an effective therapy for IPF remains a significant challenge in both medicine and pharmacology. This work delves into microarray results from lung samples of IPF patients and murine samples at different stages of bleomycin-induced pulmonary fibrosis. By discussing common pathways identified in both IPF and the experimental model, we aim to shed light on potential targets for therapeutic intervention. Dysregulation caused by abnormal chemokine levels observed in IPF lungs may activate multiple targets, suggesting that chemokine signaling plays a central role in maintaining or perpetuating lung fibrogenesis. The highlighted chemokine axes (CCL8-CCR2, CCL19/CCL21-CCR7, CXCL9-CXCR3, CCL3/CCL4/CCL5-CCR5, and CCL20-CCR6) present promising opportunities for advancing IPF treatment research and uncovering new pharmacological targets within the chemokine system.

Pharmacodynamic, prognostic, and predictive biomarkers in severe and critical COVID-19 patients treated with sirukumab

We examined candidate biomarkers for efficacy outcomes in hospitalized COVID-19 patients who were treated with sirukumab, an IL-6 neutralizing antibody, in a randomized, double-blind, placebo-controlled, phase 2 trial. Between May 2020 and March 2021, 209 patients were randomized (sirukumab, n = 139; placebo, n = 70); 112 had critical COVID-19. Serum biomarkers were evaluated for the pharmacodynamic effect of sirukumab and for their potential prognostic and predictive effect on time to sustained clinical improvement up to Day 28, clinical improvement at Day 28, and mortality at Day 28. The absence of detectable IL-4 increase and smaller increases in CCL13 post-baseline were most significantly associated with better response to sirukumab (versus placebo) treatment for all clinical efficacy outcomes tested, especially in patients with critical COVID-19. These data suggest that patients with critical COVID-19 without detectable sirukumab-induced IL-4 levels are more likely to benefit from sirukumab treatment. ClinicalTrials.gov Identifier: NCT04380961.

Impact of soluble epoxide hydrolase inhibition on silica-induced pulmonary fibrosis, ectopic lymphoid neogenesis, and autoantibody production in lupus-prone mice

OBJECTIVE

Acute intranasal (IN) instillation of lupus-prone NZBWF1 mice with crystalline silica (cSiO2) triggers robust lung inflammation that drives autoimmunity. Prior studies in other preclinical models show that soluble epoxide hydrolase (sEH) inhibition upregulates pro-resolving lipid metabolites that are protective against pulmonary inflammation. Herein, we assessed in NZBWF1 mice how acute IN cSiO2 exposure with or without the selective sEH inhibitor TPPU influences lipidomic, transcriptomic, proteomic, and histopathological biomarkers of inflammation, fibrosis, and autoimmunity.

METHODS

Female 6-week-old NZBWF1 mice were fed control or TPPU-supplemented diets for 2 weeks then IN instilled with 2.5 mg cSiO2 or saline vehicle. Cohorts were terminated at 7 or 28 days post-cSiO2 instillation (PI) and lungs analyzed for prostaglandins, cytokines/chemokines, gene expression, differential cell counts, histopathology, and autoantibodies.

RESULTS

cSiO2-treatment induced prostaglandins, cytokines/chemokine, proinflammatory gene expression, CD206+ monocytes, Ly6B.2+ neutrophils, CD3+ T cells, CD45R+ B cells, centriacinar inflammation, collagen deposition, ectopic lymphoid structure neogenesis, and autoantibodies. While TPPU effectively inhibited sEH as reflected by skewed lipidomic profile in lung and decreased cSiO2-induced monocytes, neutrophils, and lymphocytes in lung lavage fluid, it did not significantly impact other biomarkers.

DISCUSSION

cSiO2 evoked robust pulmonary inflammation and fibrosis in NZBWF1 mice that was evident at 7 days PI and progressed to ELS development and autoimmunity by 28 days PI. sEH inhibition by TPPU modestly suppressed cSiO2-induced cellularity changes and pulmonary fibrosis. However, TPPU did not affect ELS formation or autoantibody responses, suggesting sEH minimally impacts cSiO2-triggered lung inflammation, fibrosis, and early autoimmunity in our model.

CCL22 Induces the Polarization of Immature Dendritic Cells into Tolerogenic Dendritic Cells in Radiation-Induced Lung Injury through the CCR4-Dectin2-PLC-γ2-NFATC2-Nr4a2-PD-L1 Signaling Pathway

Recruitment of immune cells to the injury site plays a pivotal role in the pathology of radiation-associated diseases. In this study, we investigated the impact of the chemokine CCL22 released from alveolar type II epithelial (AT2) cells after irradiation on the recruitment and functional changes of dendritic cells (DCs) in the development of radiation-induced lung injury (RILI). By examining changes in CCL22 protein levels in lung tissue of C57BL/6N mice with RILI, we discovered that ionizing radiation increased CCL22 expression in irradiated alveolar AT2 cells, as did MLE-12 cells after irradiation. A transwell migration assay revealed that CCL22 promoted the migration of CCR4-positive DCs to the injury site, which explained the migration of pulmonary CCR4-positive DCs in RILI mice in vivo. Coculture experiments demonstrated that, consistent with the response of regulatory T cells in the lung tissue of RILI mice, exogenous CCL22-induced DCs promoted regulatory T cell proliferation. Mechanistically, we demonstrated that Dectin2 and Nr4a2 are key targets in the CCL22 signaling pathway, which was confirmed in pulmonary DCs of RILI mice. As a result, CCL22 upregulated the expression of PD-L1, IL-6, and IL-10 in DCs. Consequently, we identified a mechanism in which CCL22 induced DC tolerance through the CCR4-Dectin2-PLC-γ2-NFATC2-Nr4a2-PD-L1 pathway. Collectively, these findings demonstrated that ionizing radiation stimulates the expression of CCL22 in AT2 cells to recruit DCs to the injury site and further polarizes them into a tolerant subgroup of CCL22 DCs to regulate lung immunity, ultimately providing potential therapeutic targets for DC-mediated RILI.

Bortezomib restrains M2 polarization and reduces CXCL16-associated CXCR6+CD4 T cell chemotaxis in bleomycin-induced pulmonary fibrosis

BACKGROUND

The development of pulmonary fibrosis involves a cascade of events, in which inflammation mediated by immune cells plays a pivotal role. Chemotherapeutic drugs have been shown to have dual effects on fibrosis, with bleomycin exacerbating pulmonary fibrosis and bortezomib alleviating tissue fibrotic processes. Understanding the intricate interplay between chemotherapeutic drugs, immune responses, and pulmonary fibrosis is likely to serve as the foundation for crafting tailored therapeutic strategies.

METHODS

A model of bleomycin-induced pulmonary fibrosis was established, followed by treatment with bortezomib. Tissue samples were collected for analysis of immune cell subsets and functional assessment by flow cytometry and in vitro cell experiments. Additionally, multi-omics analysis was conducted to further elucidate the expression of chemokines and chemokine receptors, as well as the characteristics of cell populations.

RESULTS

Here, we observed that the expression of CXCL16 and CXCR6 was elevated in the lung tissue of a pulmonary fibrosis model. In the context of pulmonary fibrosis or TGF-β1 stimulation in vitro, macrophages exhibited an M2-polarized phenotype and secreted more CXCL16 than those of the control group. Moreover, flow cytometry revealed increased expression levels of CD69 and CXCR6 in pulmonary CD4 T cells during fibrosis progression. The administration of bortezomib alleviated bleomycin-induced pulmonary fibrosis, accompanied by reduced ratio of M2-polarized macrophages and decreased accumulation of CD4 T cells expressing CXCR6.

CONCLUSIONS

Our findings provide insights into the key immune players involved in bleomycin-induced pulmonary fibrosis and offer preclinical evidence supporting the repurposing strategy and combination approaches to reduce lung fibrosis.

Dual effects of radiotherapy on tumor microenvironment and its contribution towards the development of resistance to immunotherapy in gastrointestinal and thoracic cancers

Successful clinical methods for tumor elimination include a combination of surgical resection, radiotherapy, and chemotherapy. Radiotherapy is one of the crucial components of the cancer treatment regimens which allow to extend patient life expectancy. Current cutting-edge radiotherapy research is focused on the identification of methods that should increase cancer cell sensitivity to radiation and activate anti-cancer immunity mechanisms. Radiation treatment activates various cells of the tumor microenvironment (TME) and impacts tumor growth, angiogenesis, and anti-cancer immunity. Radiotherapy was shown to regulate signaling and anti-cancer functions of various TME immune and vasculature cell components, including tumor-associated macrophages, dendritic cells, endothelial cells, cancer-associated fibroblasts (CAFs), natural killers, and other T cell subsets. Dual effects of radiation, including metastasis-promoting effects and activation of oxidative stress, have been detected, suggesting that radiotherapy triggers heterogeneous targets. In this review, we critically discuss the activation of TME and angiogenesis during radiotherapy which is used to strengthen the effects of novel immunotherapy. Intracellular, genetic, and epigenetic mechanisms of signaling and clinical manipulations of immune responses and oxidative stress by radiotherapy are accented. Current findings indicate that radiotherapy should be considered as a supporting instrument for immunotherapy to limit the cancer-promoting effects of TME. To increase cancer-free survival rates, it is recommended to combine personalized radiation therapy methods with TME-targeting drugs, including immune checkpoint inhibitors.

CCL17 drives fibroblast activation in the progression of pulmonary fibrosis by enhancing the TGF-β/Smad signaling

Pulmonary fibrosis (PF) is a type of fatal respiratory diseases with limited therapeutic options and poor prognosis. The chemokine CCL17 plays crucial roles in the pathogenesis of immune diseases. Bronchoalveolar lavage fluid (BALF) CCL17 levels are significantly higher in patients with idiopathic PF (IPF) than in healthy volunteers. However, the source and function of CCL17 in PF remain unclear. Here, we demonstrated that the levels of CCL17 were increased in the lungs of IPF patients and mice with bleomycin (BLM)-induced PF. In particular, CCL17 were upregulated in alveolar macrophages (AMs) and antibody blockade of CCL17 protected mice against BLM-induced fibrosis and significantly reduced fibroblast activation. Mechanistic studies revealed that CCL17 interacted with its receptor CCR4 on fibroblasts, thereby activating the TGF-β/Smad signaling pathway to promote fibroblast activation and tissue fibrosis. Moreover, the knockdown of CCR4 by CCR4-siRNA or blockade by CCR4 antagonist C-021 was able to ameliorate PF pathology in mice. In summary, the CCL17-CCR4 axis is involved in the progression of PF, and targeting of CCL17 or CCR4 inhibits fibroblast activation and tissue fibrosis and may benefit patients with fibroproliferative lung diseases.

CC chemokines family in fibrosis and aging: From mechanisms to therapy

Fibrosis is a universal aging-related pathological process in the different organ, but is actually a self-repair excessive response. To date, it still remains a large unmet therapeutic need to restore injured tissue architecture without detrimental side effects, due to the limited clinical success in the treatment of fibrotic disease. Although specific organ fibrosis and the associated triggers have distinct pathophysiological and clinical manifestations, they often share involved cascades and common traits, including inflammatory stimuli, endothelial cell injury, and macrophage recruitment. These pathological processes can be widely controlled by a kind of cytokines, namely chemokines. Chemokines act as a potent chemoattractant to regulate cell trafficking, angiogenesis, and extracellular matrix (ECM). Based on the position and number of N-terminal cysteine residues, chemokines are divided into four groups: the CXC group, the CX3C group, the (X)C group, and the CC group. The CC chemokine classes (28 members) is the most numerous and diverse subfamily of the four chemokine groups. In this Review, we summarized the latest advances in the understanding of the importance of CC chemokine in the pathogenesis of fibrosis and aging and discussed potential clinical therapeutic strategies and perspectives aimed at resolving excessive scarring formation.

Diagnosis of Fibrotic Hypersensitivity Pneumonitis: Is There a Role for Biomarkers?

Hypersensitivity pneumonitis is a complex interstitial lung syndrome and is associated with significant morbimortality, particularly for fibrotic disease. This condition is characterized by sensitization to a specific antigen, whose early identification is associated with improved outcomes. Biomarkers measure objectively biologic processes and may support clinical decisions. These tools evolved to play a crucial role in the diagnosis and management of a wide range of human diseases. This is not the case, however, with hypersensitivity pneumonitis, where there is still great room for research in the path to find consensual diagnostic biomarkers. Gaps in the current evidence include lack of validation, validation against healthy controls alone, small sampling and heterogeneity in diagnostic and classification criteria. Furthermore, discriminatory accuracy is currently limited by overlapping mechanisms of inflammation, damage and fibrogenesis between ILDs. Still, biomarkers such as BAL lymphocyte counts and specific serum IgGs made their way into clinical guidelines, while others including KL-6, SP-D, YKL-40 and apolipoproteins have shown promising results in leading centers and have potential to translate into daily practice. As research proceeds, it is expected that the emergence of novel categories of biomarkers will offer new and thriving tools that could complement those currently available.

CC Chemokines in Idiopathic Pulmonary Fibrosis: Pathogenic Role and Therapeutic Potential

Idiopathic pulmonary fibrosis (IPF), characterized by progressive worsening of dyspnea and irreversible decline in lung function, is a chronic and progressive respiratory disease with a poor prognosis. Chronic or repeated lung injury results in inflammation and an excessive injury-repairing response that drives the development of IPF. A number of studies have shown that the development and progression of IPF are associated with dysregulated expression of several chemokines and chemokine receptors, several of which have been used as predictors of IPF outcome. Chemokines of the CC family play significant roles in exacerbating IPF progression by immune cell attraction or fibroblast activation. Modulating levels of detrimental CC chemokines and interrupting the corresponding transduction axis by neutralizing antibodies or antagonists are potential treatment options for IPF. Here, we review the roles of different CC chemokines in the pathogenesis of IPF, and their potential use as biomarkers or therapeutic targets.

Cellular and Molecular Control of Lipid Metabolism in Idiopathic Pulmonary Fibrosis: Clinical Application of the Lysophosphatidic Acid Pathway

Idiopathic pulmonary fibrosis (IPF) is a representative disease that causes fibrosis of the lungs. Its pathogenesis is thought to be characterized by sustained injury to alveolar epithelial cells and the resultant abnormal tissue repair, but it has not been fully elucidated. IPF is currently difficult to cure and is known to follow a chronic progressive course, with the patient's survival period estimated at about three years. The disease occasionally exacerbates acutely, leading to a fatal outcome. In recent years, it has become evident that lipid metabolism is involved in the fibrosis of lungs, and various reports have been made at the cellular level as well as at the organic level. The balance among eicosanoids, sphingolipids, and lipid composition has been reported to be involved in fibrosis, with particularly close attention being paid to a bioactive lipid "lysophosphatidic acid (LPA)" and its pathway. LPA signals are found in a wide variety of cells, including alveolar epithelial cells, vascular endothelial cells, and fibroblasts, and have been reported to intensify pulmonary fibrosis via LPA receptors. For instance, in alveolar epithelial cells, LPA signals reportedly induce mitochondrial dysfunction, leading to epithelial damage, or induce the transcription of profibrotic cytokines. Based on these mechanisms, LPA receptor inhibitors and the metabolic enzymes involved in LPA formation are now considered targets for developing novel means of IPF treatment. Advances in basic research on the relationships between fibrosis and lipid metabolism are opening the path to new therapies targeting lipid metabolism in the treatment of IPF.

Biomarker Changes and Molecular Signatures Associated with Takayasu Arteritis Following Treatment with Glucocorticoids and Tofacitinib

Objective

This study aimed to analyze biomarker changes in patients with TAK following treatment with glucocorticoids (GCs) and tofacitinib (TOF).

Methods

Seventeen patients from a prospective TAK cohort treated with GCs and TOF and 12 healthy individuals were recruited. TAK associated cytokines, chemokines, growth factors, and MMPs were analyzed in these patients before and after GCs and TOF treatment, and healthy controls. Molecular signatures associated with clinical features were evaluated.

Results

Patients’ cytokines (PTX3, IL-6, IFN-γ), chemokines (IL-16, CCL22, CCL2), growth factors (VEGF), and MMP9 levels were significantly higher at baseline (all p < 0.05), while patients’ FGF-2 levels were significantly lower (p = 0.02). After treatment, IL-10 was significantly increased at 6 months (p=0.007), and inflammatory cytokines such as PTX3, IL-6 demonstrated a downward trend. Patients without vascular occlusion had higher baseline CCL22 levels than patients with it (p = 0.05), which remained persistently higher after treatment. Radar plot analysis demonstrated that PTX3 was closely correlated with disease activity. In addition, patients without imaging improvement had relatively higher baseline levels of CCL22, FGF-2, and PDGF-AB (p = 0.056, p = 0.06 and p = 0.08 respectively) and lower baseline levels of TNFα, ESR, and CRP (p=0.04, p=0.056, p=0.07, respectively) compared with patients without it.

Conclusion

GCs and TOF are effective in decreasing inflammatory molecules but have limited efficacy in regulating multiple other markers involved in TAK. PTX3 is a prominent marker for disease activity, and CCL22 may have a predictive value for vascular progression.

Novel drug delivery systems and disease models for pulmonary fibrosis

Pulmonary fibrosis (PF) is a serious and progressive lung disease which is possibly life-threatening. It causes lung scarring and affects lung functions including epithelial cell injury, massive recruitment of immune cells and abnormal accumulation of extracellular matrix (ECM). There is currently no cure for PF. Treatment for PF is aimed at slowing the course of the disease and relieving symptoms. Pirfenidone (PFD) and nintedanib (NDNB) are currently the only two FDA-approved oral medicines to slow down the progress of idiopathic pulmonary fibrosis, a specific type of PF. Novel drug delivery systems and therapies have been developed to improve the prognosis of the disease, as well as reduce or minimize the toxicities during drug treatment. The drug delivery routes for these therapies are various including oral, intravenous, nasal, inhalant, intratracheal and transdermal; although this is dependent on specific treatment mechanisms. In addition, researchers have also expanded current animal models that could not fully restore the clinicopathology, and developed a series of in vitro models such as organoids to study the pathogenesis and treatment of PF. This review describes recent advances on pathogenesis exploration, classifies and specifies the progress of drug delivery systems by their delivery routes, as well as an overview on the in vitro and in vivo models for PF research.

Role of macrophages in tumor progression and therapy (Review)

The number and phenotype of macrophages are closely related to tumor growth and prognosis. Macrophages are recruited to (and polarized at) the tumor site thereby promoting tumor growth, stimulating tumor angiogenesis, facilitating tumor cell migration, and creating a favorable environment for subsequent colonization by (and survival of) tumor cells. These phenomena contribute to the formation of an immunosuppressive tumor microenvironment (TME) and therefore speed up tumor cell proliferation and metastasis and reduce the efficacy of antitumor factors and therapies. The ability of macrophages to remodel the TME through interactions with other cells and corresponding changes in their number, activity, and phenotype during conventional therapies, as well as the association between these changes and drug resistance, make tumor-associated macrophages a new target for antitumor therapies. In this review, advantages and limitations of the existing antitumor strategies targeting macrophages in Traditional Chinese and Western medicine were analyzed, starting with the effect of macrophages on tumors and their interactions with other cells and then the role of macrophages in conventional treatments was explored. Possible directions of future developments in this field from an all-around multitarget standpoint were also examined.

The roles of CC chemokines in response to radiation

Radiotherapy is an effective regimen for cancer treatment alone or combined with chemotherapy or immunotherapy. The direct effect of radiotherapy involves radiation-induced DNA damage, and most studies have focused on this area to improve the efficacy of radiotherapy. Recently, the immunomodulatory effect of radiation on the tumour microenvironment has attracted much interest. Dying tumour cells can release multiple immune-related molecules, including tumour-associated antigens, chemokines, and inflammatory mediators. Then, immune cells are attracted to the irradiated site, exerting immunostimulatory or immunosuppressive effects. CC chemokines play pivotal roles in the trafficking process. The CC chemokine family includes 28 members that attract different immune subsets. Upon irradiation, tumour cells or immune cells can release different CC chemokines. Here, we mainly discuss the importance of CCL2, CCL3, CCL5, CCL8, CCL11, CCL20 and CCL22 in radiotherapy. In irradiated normal tissues, released chemokines induce epithelial to mesenchymal transition, thus promoting tissue injury. In the tumour microenvironment, released chemokines recruit cancer-associated cells, such as tumour-infiltrating lymphocytes, myeloid-derived suppressor cells and tumour-associated macrophages, to the tumour niche. Thus, CC chemokines have protumour and antitumour properties. Based on the complex roles of CC chemokines in the response to radiation, it would be promising to target specific chemokines to alleviate radiation-induced injury or promote tumour control.

A comprehensive profile of chemokines in the peripheral blood and vascular tissue of patients with Takayasu arteritis

Background

Takayasu arteritis (TAK) is a chronic granulomatous large vessel vasculitis with multiple immune cells involved. Chemokines play critical roles in recruitment and activation of immune cells. This study aimed to investigate chemokine profile in the peripheral blood and vascular tissue of patients with TAK.

Methods

A total of 58 patients with TAK and 53 healthy controls were enrolled. Chemokine array assay was performed in five patients with TAK and three controls. Chemokines with higher levels were preliminarily validated in 20 patients and controls. The validated chemokines were further confirmed in another group of samples with 25 patients and 25 controls. Their expression and distribution were also examined in vascular tissue from 8 patients and 5 controls. Correlations between these chemokines and peripheral immune cells, cytokines, and disease activity parameters were analyzed. Their serum changes were also investigated in these 45 patients after glucocorticoids and immunosuppressive treatment.

Results

Patients and controls were age and sex-matched. Twelve higher chemokines and 4 lower chemokines were found based on the chemokine array. After validation, increase of 5 chemokines were confirmed in patients with TAK, including CCL22, RANTES, CXCL16, CXCL11, and IL-16. Their expressions were also increased in vascular tissue of patients with TAK. In addition, levels of RANTES and IL-16 were positively correlated with peripheral CD3⁺CD4⁺ T cell numbers. Close localization of CCL22, CXCL11, or IL-16 with inflammatory cells was also observed in TAK vascular tissue. No correlations were found between these chemokines and cytokines (IL-6, IL-17, IFN-γ) or inflammatory parameters (ESR, CRP). No differences were observed regarding with these chemokines between active and inactive patients. After treatment, increase of CCL22 and decrease of RANTES and CXCL16 were found, while no changes were showed in levels of CXCL11 and IL-16.

Conclusions

CCL22, RANTES, CXCL16, CXCL11, and IL-16 were identified as the major chemokines involved in the recruitment of immune cells in the vascular tissue of patients with TAK. Additionally, the persistently high levels of CCL22, CXCL11, and IL-16 observed after treatment indicate their role in vascular chronic inflammation or fibrosis and demonstrate the need for developing more efficacious treatment options.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02740-x.

Development of nanotechnology-mediated precision radiotherapy for anti-metastasis and radioprotection

Radiotherapy (RT), including external beam RT and internal radiation therapy, uses high-energy ionizing radiation to kill tumor cells.

C-C Motif Chemokine Ligand-17 as a Novel Biomarker and Regulator of Epithelial Mesenchymal Transition in Renal Fibrogenesis

CCL17, a chemotactic cytokine produced by macrophages, is known to promote inflammatory and fibrotic effects in multiple organs, but its role in mediating renal fibrosis is unclear. In our study cohort of 234 chronic kidney disease (CKD) patients and 65 healthy controls, human cytokine array analysis revealed elevated CCL17 expression in CKD that correlated negatively with renal function. The area under the receiver operating characteristic curve of CCL17 to predict the development of CKD stages 3b–5 was 0.644 (p < 0.001), with the optimal cut-off value of 415.3 ng/mL. In vitro over-expression of CCL17 in HK2 cells had no effect on cell viability, but increased cell motility and the expression of α-SMA, vimentin and collagen I, as shown by western blot analysis. In a unilateral ureteral obstruction (UUO) mouse model, we observed significantly increased interstitial fibrosis and renal tubule dilatation by Masson’s Trichrome and H&E staining, and markedly increased expression of CCL17, vimentin, collagen I, and α-SMA by IHC stain, qRTPCR, and western blotting. CCL17 induced renal fibrosis by promoting the epithelial-mesenchymal transition, resulting in ECM accumulation. CCL17 may be a useful biomarker for predicting the development of advanced CKD.

Functional Contribution and Targeted Migration of Group-2 Innate Lymphoid Cells in Inflammatory Lung Diseases: Being at the Right Place at the Right Time

During the last decade, group-2 innate lymphoid cells (ILC2s) have been discovered and successfully established as crucial mediators of lung allergy, airway inflammation and fibrosis, thus affecting the pathogenesis and clinical course of many respiratory diseases, like for instance asthma, cystic fibrosis and chronic rhinosinusitis. As an important regulatory component in this context, the local pulmonary milieu at inflammatory tissue sites does not only determine the activation status of lung-infiltrating ILC2s, but also influences their motility and migratory behavior. In general, many data collected in recent murine and human studies argued against the former concept of a very strict tissue residency of innate lymphoid cells (ILCs) and instead pointed to a context-dependent homing capacity of peripheral blood ILC precursors and the inflammation-dependent capacity of specific ILC subsets for interorgan trafficking. In this review article, we provide a comprehensive overview of the so far described molecular mechanisms underlying the pulmonary migration of ILC2s and thereby the numeric regulation of local ILC2 pools at inflamed or fibrotic pulmonary tissue sites and discuss their potential to serve as innovative therapeutic targets in the treatment of inflammatory lung diseases.

A novel nomogram containing acute radiation esophagitis predicting radiation pneumonitis in thoracic cancer receiving radiotherapy

Background

Radiation-induced pneumonitis (RP) is a non-negligible and sometimes life-threatening complication among patients with thoracic radiation. We initially aimed to ascertain the predictive value of acute radiation-induced esophagitis (SARE, grade ≥ 2) to symptomatic RP (SRP, grade ≥ 2) among thoracic cancer patients receiving radiotherapy. Based on that, we established a novel nomogram model to provide individualized risk assessment for SRP.

Methods

Thoracic cancer patients who were treated with thoracic radiation from Jan 2018 to Jan 2019 in Shandong Cancer Hospital and Institute were enrolled prospectively. All patients were followed up during and after radiotherapy (RT) to observe the development of esophagitis as well as pneumonitis. Variables were analyzed by univariate and multivariate analysis using the logistic regression model, and a nomogram model was established to predict SRP by “R” version 3.6.0.

Results

A total of 123 patients were enrolled (64 esophageal cancer, 57 lung cancer and 2 mediastinal cancer) in this study prospectively. RP grades of 0, 1, 2, 3, 4 and 5 occurred in 29, 57, 31, 0, 3 and 3 patients, respectively. SRP appeared in 37 patients (30.1%). In univariate analysis, SARE was shown to be a significant predictive factor for SRP (P < 0.001), with the sensitivity 91.9% and the negative predictive value 93.5%. The incidence of SRP in different grades of ARE were as follows: Grade 0–1: 6.5%; Grade 2: 36.9%; Grade 3: 80.0%; Grade 4: 100%. Besides that, the dosimetric factors considering total lung mean dose, total lung V5, V20, ipsilateral lung mean dose, ipsilateral lung V5, and mean esophagus dose were correlated with SRP (all P < 0.05) by univariate analysis. The incidence of SRP was significantly higher in patients whose symptoms of RP appeared early. SARE, mean esophagus dose and ipsilateral mean lung dose were still significant in multivariate analysis, and they were included to build a predictive nomogram model for SRP.

Conclusions

As an early index that can reflect the tissue’s radiosensitivity visually, SARE can be used as a predictor for SRP in patients receiving thoracic radiation. And the nomogram containing SARE may be fully applied in future’s clinical work.

Role of CCR2+ Myeloid Cells in Inflammation Responses Driven by Expression of a Surfactant Protein-C Mutant in the Alveolar Epithelium

Acute inflammatory exacerbations (AIE) represent precipitous deteriorations of a number of chronic lung conditions, including pulmonary fibrosis (PF), chronic obstructive pulmonary disease and asthma. AIEs are marked by diffuse and persistent polycellular alveolitis that profoundly accelerate lung function decline and mortality. In particular, excess monocyte mobilization during AIE and their persistence in the lung have been linked to poor disease outcome. The etiology of AIEs remains quite uncertain, but environmental exposure and genetic predisposition/mutations have been identified as two contributing factors. Guided by clinical evidence, we have developed a mutant model of pulmonary fibrosis leveraging the PF-linked missense isoleucine to threonine substitution at position 73 [I73T] in the alveolar type-2 cell-restricted Surfactant Protein-C [SP-C] gene [SFTPC]. With this toolbox at hand, the present work investigates the role of peripheral monocytes during the initiation and progression of AIE-PF. Genetic ablation of CCR2⁺ monocytes (SP-C^I73TCCR2^KO) resulted in improved lung histology, mouse survival, and reduced inflammation compared to SP-C^I73TCCR2^WT cohorts. FACS analysis of CD11b⁺CD64^-Ly6C^hi monocytes isolated 3 d and 14 d after SP-C^I73T induced injury reveals dynamic transcriptional changes associated with “Innate Immunity’ and ‘Extracellular Matrix Organization’ signaling. While immunohistochemical and in situ hybridization analysis revealed comparable levels of tgfb1 mRNA expression localized primarily in parenchymal cells found nearby foci of injury we found reduced effector cell activation (C1q, iNOS, Arg1) in SP-C^I73TCCR2^KO lungs as well as partial colocalization of tgfb1 mRNA expression in Arg1⁺ cells. These results provide a detailed picture of the role of resident macrophages and recruited monocytes in the context of AIE-PF driven by alveolar epithelial dysfunction.

Regulation of extracellular matrix assembly and structure by hybrid M1/M2 macrophages

Aberrant extracellular matrix (ECM) assembly surrounding implanted biomaterials is the hallmark of the foreign body response, in which implants become encapsulated in thick fibrous tissue that prevents their proper function. While macrophages are known regulators of fibroblast behavior, how their phenotype influences ECM assembly and the progression of the foreign body response is poorly understood. In this study, we used in vitro models with physiologically relevant macrophage phenotypes, as well as controlled release of macrophage-modulating cytokines from gelatin hydrogels implanted subcutaneously in vivo to investigate the role of macrophages in ECM assembly. Primary human macrophages were polarized to four distinct phenotypes, which have each been associated with fibrosis, including pro-inflammatory M1, pro-healing M2, and a hybrid M1/M2, generated by exposing macrophages to M1-and M2-promoting stimuli simultaneously. Additionally, macrophages were first polarized to M1 and then to M2 (M1→M2) to generate a phenotype typically observed during normal wound healing. Human dermal fibroblasts that were cultured in macrophage-conditioned media upregulated numerous genes involved in regulation of ECM assembly, especially in M2-conditioned media. Hybrid M1/M2 macrophage-conditioned media caused fibroblasts to produce a matrix with thicker and less aligned fibers, while M2 macrophage-conditioned media caused the formation of a more aligned matrix with thinner fibers. Gelatin methacrylate hydrogels containing interleukin-4 (IL4) and IL13-loaded poly(lactic-co-glycolic acid) (PLGA) microparticles were designed to promote the M2 phenotype in a murine subcutaneous in vivo model. NanoString multiplex gene expression analysis of hydrogel explants showed that hydrogels without cytokines caused mostly M1 phenotype markers to be highly expressed at an early time point (3 days), but the release of IL4+IL13 promoted upregulation of M2 markers and genes associated with regulation of ECM assembly, such as Col5a1 and Col6a1. Biochemical analysis and second harmonic generation microscopy showed that the release of IL4+IL13 increased total sulfated glycosaminoglycan content and decreased fibril alignment, which is typically associated with less fibrotic tissue. Together, these results show that hybrid M1/M2 macrophages regulate ECM assembly, and that shifting the balance towards M2 may promote architectural and compositional changes in ECM with enhanced potential for downstream remodeling.

Pulmonary toxicants and fibrosis: innate and adaptive immune mechanisms

Pulmonary fibrosis is characterized by destruction and remodeling of the lung due to an accumulation of collagen and other extracellular matrix components in the tissue. This results in progressive irreversible decreases in lung capacity, impaired gas exchange and eventually, hypoxemia. A number of inhaled and systemic toxicants including bleomycin, silica, asbestos, nanoparticles, mustard vesicants, nitrofurantoin, amiodarone, and ionizing radiation have been identified. In this article, we review the role of innate and adaptive immune cells and mediators they release in the pathogenesis of fibrotic pathologies induced by pulmonary toxicants. A better understanding of the pathogenic mechanisms underlying fibrogenesis may lead to the development of new therapeutic approaches for patients with these debilitating and largely irreversible chronic diseases.

Epithelial Expression of an Interstitial Lung Disease-Associated Mutation in Surfactant Protein-C Modulates Recruitment and Activation of Key Myeloid Cell Populations in Mice

Patients with idiopathic pulmonary fibrosis (IPF) often experience precipitous deteriorations, termed "acute exacerbations" (AE), marked by diffuse alveolitis and altered gas exchange, resulting in a significant loss of lung function or mortality. The missense isoleucine to threonine substitution at position 73 (I73T) in the alveolar type 2 cell-restricted surfactant protein-C (SP-C) gene (SFTPC) has been linked to clinical IPF. To better understand the sequence of events that impact AE-IPF, we leveraged a murine model of inducible SP-C^I73T (SP-C^I73T/I73TFlp^+/- ) expression. Following administration of tamoxifen to 8-12-wk-old mice, an upregulation of Sftpc^I73T initiated a diffuse lung injury marked by increases in bronchoalveolar lavage fluid (BALF) protein and histochemical evidence of CD45⁺ and CD11b⁺ cell infiltrates. Flow cytometry of collagenase-digested lung cells revealed a transient, early reduction in SiglecF^hiCD11b^lowCD64^hiCD11c^hi macrophages, countered by the sequential accumulation of SiglecF^loCD11b⁺CD64^-CD11c^-CCR2⁺Ly6C⁺ immature macrophages (3 d), Ly6G⁺ neutrophils (7 d), and SiglecF^hiCD11b^hiCD11c^lo eosinophils (2 wk). By mRNA analysis, BALF cells demonstrated a time-dependent phenotypic shift from a proinflammatory (3 d) to an anti-inflammatory/profibrotic activation state, along with serial elaboration of monocyte and eosinophil recruitment factors. The i.v. administration of clodronate effectively reduced total BALF cell numbers, CCR2⁺ immature macrophages, and eosinophil influx while improving survival. In contrast, resident macrophage depletion from the intratracheal delivery of clodronate liposomes enhanced Sftpc^I73T -induced mortality. These results using Sftpc^I73T mice provide a detailed ontogeny for AE-IPF driven by alveolar epithelial dysfunction that induces a polycellular inflammation initiated by the early influx of proinflammatory CCR2⁺Ly6C^hi immature macrophages.

Modeling and multiscale characterization of the quantitative imaging based fibrosis index reveals pathophysiological, transcriptome and proteomic correlates of lung fibrosis induced by fractionated irradiation

Pulmonary fibrosis represents a leading cause of morbidity and mortality worldwide. Therapy induced lung fibrosis constitutes a pivotal dose‐limiting side effect of radiotherapy and other anticancer agents. We aimed to develop objective criteria for assessment of fibrosis and discover pathophysiological and molecular correlates of lung fibrosis as a function of fractionated whole thoracic irradiation. Dose–response series of fractionated irradiation was utilized to develop a non‐invasive and quantitative measure for the degree of fibrosis – the fibrosis index (FI). The correlation of FI with histopathology, blood‐gas, transcriptome and proteome responses of the lung tissue was analyzed. Macrophages infiltration and polarization was assessed by immunohistochemistry. Fibrosis development followed a slow kinetic with maximum lung fibrosis levels detected at 24‐week post radiation insult. FI favorably correlated with radiation dose and surrogates of lung fibrosis i.e., enhanced pro‐inflammatory response, tissue remodeling and extracellular matrix deposition. The loss of lung architecture correlated with decreased epithelial marker, loss of microvascular integrity with decreased endothelial and elevated mesenchymal markers. Lung fibrosis was further attributed to a switch of the inflammatory state toward a macrophage/T‐helper cell type 2‐like (M2/Th2) polarized phenotype. Together, the multiscale characterization of FI in radiation‐induced lung fibrosis (RILF) model identified pathophysiological, transcriptional and proteomic correlates of fibrosis. Pathological immune response and endothelial/epithelial to mesenchymal transition were discovered as critical events governing lung tissue remodeling. FI will be instrumental for deciphering the molecular mechanisms governing lung fibrosis and discovery of novel targets for treatment of this devastating disease with an unmet medical need.

What's new?

The development of fibrosis scar tissue in the lungs is a dose‐limiting effect of radiotherapy for thoracic malignancies. Molecular mechanisms driving radiation‐induced lung fibrosis (RILF), however, remain unclear. In this study, a fibrosis index (FI) was devised to quantitatively detect spatial and temporal kinetics of lung fibrosis development. Multi‐scale characterization of FI uncovered mechanisms governing lung fibrosis, including perturbation of immune balance and microvascular integrity. Radiation dose and FI were correlated with an inflammatory switch toward a macrophage/T‐helper cell type 2‐like polarized phenotype. The findings open the way for further mechanistic study and the discovery of therapeutic targets for RILF.

Immunomodulation of the Tumor Microenvironment: Turn Foe Into Friend

Immunotherapy, where the patient's own immune system is exploited to eliminate tumor cells, has become one of the most prominent new cancer treatment options in the last decade. The main hurdle for classical cancer vaccines is the need to identify tumor- and patient specific antigens to include in the vaccine. Therefore, in situ vaccination represents an alternative and promising approach. This type of immunotherapy involves the direct intratumoral administration of different immunomodulatory agents and uses the tumor itself as the source of antigen. The ultimate aim is to convert an immunodormant tumor microenvironment into an immunostimulatory one, enabling the immune system to eradicate all tumor lesions in the body. In this review we will give an overview of different strategies, which can be exploited for the immunomodulation of the tumor microenvironment and their emerging role in the treatment of cancer patients.

Anti-glucocorticoid-induced Tumor Necrosis Factor-Related Protein (GITR) Therapy Overcomes Radiation-Induced Treg Immunosuppression and Drives Abscopal Effects

Despite the potential to cure metastatic disease, immunotherapy on its own often fails outright or early on due to tumor immune evasion. To address this obstacle, we investigated combinations of anti-GITR, anti-PD1 and radiation therapy (XRT) in our previously developed anti-PD1 resistant 344SQ non-small cell lung adenocarcinoma preclinical tumor model. We hypothesized that targeting multiple mechanisms of immune evasion with this triple therapy would lead to an enhanced tumor-specific immune response and improve survival more so than any mono- or dual therapy. In a two tumor 344SQR murine model, treatment with anti-GITR, anti-PD1, and XRT led to significantly improved survival and an abscopal response, with half of the mice becoming tumor free. These mice showed durable response and increased CD4+ and CD8+ effector memory on tumor rechallenge. Regulatory T cells (Tregs) expressed the highest level of GITR at the tumor site and anti-GITR therapy drastically diminished Tregs at the tumor site. Anti-tumor effects were largely dependent on CD4+ T cells and partially dependent on CD8+ T cells. Anti-GITR IgG2a demonstrated superior efficacy to anti-GITR IgG1 in driving antitumor effects. Collectively, these results suggest that combinatorial strategies targeting multiple points of tumor immune evasion may lead to a robust and lasting antitumor response.

Proton beam therapy and immunotherapy: an emerging partnership for immune activation in non-small cell lung cancer

Proton beam therapy (PBT) is becoming an increasingly common option for patients undergoing radiation therapy (RT). With the concurrent emergence of immunotherapy as an effective systemic treatment for historically treatment-resistant disease such as advanced non-small cell lung cancer (NSCLC), the combination of RT's immunoadjuvant effects with immunotherapy is gaining widespread attention. However, pre-clinical and clinical studies have shown potential immunosuppressive mechanisms associated with conventional RT that may restrict its immunogenic potential. Protons, as charged particles, exhibit both dosimetric and biological differences in normal and cancer cells that may be able to not only enhance the immunoadjuvant effects of RT, but also reduce immunosuppressive mechanisms. Here, we review the rationale, preclinical and clinical evidence, and ongoing efforts in combining PBT with immunotherapy in cancer treatment with a focus on NSCLC.

Industrial hog farming is associated with altered circulating immunological markers

OBJECTIVES

The previously observed inverse association between hog farming and risk of lung cancer in the Agricultural Health Study (AHS) has been attributed to endotoxin exposure, the levels of which are particularly high in industrial hog confinement facilities. We conducted an investigation to explore the potential biological mechanisms underlying this association, as well as other immunological changes associated with hog farming.

METHODS

Serum immune marker levels were measured using a multiplexed bead-based assay in 61 active hog farmers and 61 controls matched on age, phlebotomy date and raising cattle. Both groups comprised non-smoking male AHS participants from Iowa. We compared natural log-transformed marker levels between hog farmers and controls using multivariate linear regression models.

RESULTS

Circulating levels of macrophage-derived chemokine (CCL22), a chemokine previously implicated in lung carcinogenesis, were reduced among hog farmers (17% decrease; 95% CI -28% to -4%), in particular for those with the largest operations (>6000 hogs: 26% decrease; 95% CI -39% to -10%; p_trend=0.002). We also found that hog farmers had elevated levels of other immune markers, including macrophage inflammatory protein-3 alpha (MIP-3A/CCL20; 111% increase, 95% CI 19% to 273%), basic fibroblast growth factor (FGF-2; 93% increase, 95% CI 10% to 240%) and soluble interleukin-4 receptor (12% increase, 95% CI 1% to 25%), with particularly strong associations for MIP-3A/CCL20 and FGF-2 in winter.

CONCLUSIONS

These results provide insights into potential immunomodulatory mechanisms through which endotoxin or other exposures associated with hog farming may influence lung cancer risk, and warrant further investigation with more detailed bioaerosol exposure assessment.

Sparse Supervised Classification Methods Predict and Characterize Nanomaterial Exposures: Independent Markers of MWCNT Exposures

Recent experimental evidence indicates significant pulmonary toxicity of multiwalled carbon nanotubes (MWCNTs), such as inflammation, interstitial fibrosis, granuloma formation, and carcinogenicity. Although numerous studies explored the adverse potential of various CNTs, their comparability is often limited. This is due to differences in administered dose, physicochemical characteristics, exposure methods, and end points monitored. Here, we addressed the problem through sparse classification method, a supervised machine learning approach that can reduce the noise contained in redundant variables for discriminating among MWCNT-exposed and MWCNT-unexposed groups. A panel of proteins measured from bronchoalveolar lavage fluid (BAL) samples was used to predict exposure to various MWCNT and determine markers that are attributable to MWCNT exposure and toxicity in mice. Using sparse support vector machine-based classification technique, we identified a small subset of proteins clearly distinguishing each exposure. Macrophage-derived chemokine (MDC/CCL22), in particular, was associated with various MWCNT exposures and was independent of exposure method employed, that is, oropharyngeal aspiration versus inhalation exposure. Sustained expression of some of the selected protein markers identified also suggests their potential role in MWCNT-induced toxicity and proposes hypotheses for future mechanistic studies. Such approaches can be used more broadly for nanomaterial risk profiling studies to evaluate decisions related to dose/time-response relationships that could delineate experimental variables from exposure markers.

TWEAK/Fn14 Activation Participates in Ro52-Mediated Photosensitization in Cutaneous Lupus Erythematosus

Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) binds to its sole receptor fibroblast growth factor-inducible 14 (Fn14), participating in various inflammatory responses. Recently, TWEAK/Fn14 activation was found prominent in the lesions of cutaneous lupus erythematosus (CLE). This study was designed to further reveal the potential role of this pathway in Ro52-mediated photosensitization. TWEAK, Fn14, and Ro52 were determined in the skin lesions of patients with CLE. Murine keratinocytes received ultraviolet B (UVB) irradiation or plus TWEAK stimulation and underwent detection for Ro52 and proinflammatory cytokines. The chemotaxis of J774.2 macrophages was evaluated on TWEAK stimulation of cocultured keratinocytes. We found that TWEAK, Fn14, and downstream cytokines were highly expressed in CLE lesions that overexpressed Ro52. Moreover, TWEAK enhanced the UVB-induced Ro52 upregulation in murine keratinocytes. Meanwhile, TWEAK stimulation of keratinocytes favored the migration of macrophages through promoting the production of chemokine C–C motif ligands 17 and 22. Furthermore, Fn14 siRNA transfection or nuclear factor-kappa B (NF-κB) inhibitor abrogated the TWEAK enhancement of Ro52 expression in keratinocytes. Similarly, TNF receptor associated factor 2 (TRAF2) siRNA reduced the protein level of Ro52 in these cells upon TWEAK stimulation. Interestingly, UVB irradiation increased the expression of TNF receptor type 1 (TNFR1) but not affecting TNFR2 expression in keratinocytes. In conclusion, the TWEAK/Fn14 signaling participates in Ro52-mediated photosensitization and involves the activation of NF-κB pathway as well as the function of the TRAF2/TNFR partners.

The Role of Lymphocytes in Radiotherapy-Induced Adverse Late Effects in the Lung

Radiation-induced pneumonitis and fibrosis are dose-limiting side effects of thoracic irradiation. Thoracic irradiation triggers acute and chronic environmental lung changes that are shaped by the damage response of resident cells, by the resulting reaction of the immune system, and by repair processes. Although considerable progress has been made during the last decade in defining involved effector cells and soluble mediators, the network of pathophysiological events and the cellular cross talk linking acute tissue damage to chronic inflammation and fibrosis still require further definition. Infiltration of cells from the innate and adaptive immune systems is a common response of normal tissues to ionizing radiation. Herein, lymphocytes represent a versatile and wide-ranged group of cells of the immune system that can react under specific conditions in various ways and participate in modulating the lung environment by adopting pro-inflammatory, anti-inflammatory, or even pro- or anti-fibrotic phenotypes. The present review provides an overview on published data about the role of lymphocytes in radiation-induced lung disease and related damage-associated pulmonary diseases with a focus on T lymphocytes and B lymphocytes. We also discuss the suspected dual role of specific lymphocyte subsets during the pneumonitic phase and fibrotic phase that is shaped by the environmental conditions as well as the interaction and the intercellular cross talk between cells from the innate and adaptive immune systems and (damaged) resident epithelial cells and stromal cells (e.g., endothelial cells, mesenchymal stem cells, and fibroblasts). Finally, we highlight potential therapeutic targets suited to counteract pathological lymphocyte responses to prevent or treat radiation-induced lung disease.

Plasma Chemokine signature correlates with lung goblet cell hyperplasia in smokers with and without chronic obstructive pulmonary disease

Background

Chronic Obstructive Pulmonary Disease (COPD) is characterized by lung and systemic inflammation as well as airway goblet cell hyperplasia (GCH). Mucin production is activated in part by stimulation of the epidermal growth factor (EGF) receptor pathway through neutrophils and macrophages. How circulating cytokine levels relate to GCH is not clear.

Methods

We performed phlebotomy and bronchoscopy on 25 subjects (six nonsmokers, 11 healthy smokers, and eight COPD subjects FEV₁ 30–60 %). Six endobronchial biopsies per subject were performed. GCH was measured by measuring mucin volume density (MVD) using stereological techniques on periodic acid fast-Schiff stained samples. We measured the levels of chemokines CXCL8/IL-8, CCL2/MCP-1, CCL7/MCP-3, CCL22/MCD, CCL3/MIP-1α, and CCL4/MIP-1β, and the cytokines IL-1, IL-4, IL-6, IL-9, IL-17, EGF, and vascular endothelial growth factor (VEGF). Differences between groups were assessed using one-way ANOVA, t test, or Chi squared test. Post hoc tests after ANOVA were performed using Bonferroni correction.

Results

MVD was highest in healthy smokers (27.78 ± 10.24 μL/mm²) compared to COPD subjects (16.82 ± 16.29 μL/mm², p = 0.216) and nonsmokers (3.42 ± 3.07 μL/mm², p <0.0001). Plasma CXCL8 was highest in healthy smokers (11.05 ± 8.92 pg/mL) compared to nonsmokers (1.20 ± 21.92 pg/mL, p = 0.047) and COPD subjects (6.01 ± 5.90 pg/mL, p = 0.366). CCL22 and CCL4 followed the same trends. There were no significant differences in the other cytokines measured. When the subjects were divided into current smokers (healthy smokers and COPD current smokers) and non/ex-smokers (nonsmokers and COPD ex-smokers), plasma CXCL8, CCL22, CCL4, and MVD were greater in current smokers. No differences in other cytokines were seen. Plasma CXCL8 moderately correlated with MVD (r = 0.552, p = 0.003).

Discussion

In this small cohort, circulating levels of the chemokines CXCL8, CCL4, and CCL22, as well as MVD, attain the highest levels in healthy smokers compared to nonsmokers and COPD subjects. These findings seem to be driven by current smoking and are independent of airflow obstruction.

Conclusions

These data suggest that smoking upregulates a systemic pattern of neutrophil and macrophage chemoattractant expression, and this correlates significantly with the development of goblet cell hyperplasia.

CCR4 Controls the Suppressive Effects of Regulatory T Cells on Early and Late Events during Severe Sepsis

Sepsis is a deadly disease characterized by an overwhelming release of inflammatory mediators and the activation of different types of cells. This altered state of cell activation, termed leukocyte reprogramming, contributes to patient outcome. However, the understanding of the process underlying sepsis and the role of regulatory T cells (Tregs) in sepsis remains to be elucidated. In this study, we investigated the role of CCR4, the CCL17/CCL22 chemokine receptor, in the innate and acquired immune responses during severe sepsis and the role of Tregs in effecting the outcome. In contrast with wild-type (WT) mice subjected to cecal ligation and puncture (CLP) sepsis, CCR4-deficient (CCR4^-/-) septic mice presented an increased survival rate, significant neutrophil migration toward the infection site, a low bacterial count in the peritoneum, and reduced lung inflammation and serum cytokine levels. Thus, a better early host response may favor an adequate long-term response. Consequently, the CCR4^-/- septic mice were not susceptible to secondary fungal infection, in contrast with the WT septic mice. Furthermore, Tregs cells from the CCR4^-/- septic mice showed reduced suppressive effects on neutrophil migration (both in vivo and in vitro), lymphocyte proliferation and ROS production from activated neutrophils, in contrast with what was observed for Tregs from the WT septic mice. These data show that CCR4 is involved in immunosuppression after severe sepsis and suggest that CCR4⁺ Tregs negatively modulate the short and long-term immune responses.

TH2-Polarized CD4(+) T Cells and Macrophages Limit Efficacy of Radiotherapy

Radiotherapy and chemotherapy following surgery are mainstays of treatment for breast cancer. Although multiple studies have recently revealed the significance of immune cells as mediators of chemotherapy response in breast cancer, less is known regarding roles for leukocytes as mediating outcomes following radiotherapy. To address this question, we utilized a syngeneic orthotopic murine model of mammary carcinogenesis to investigate if response to radiotherapy could be improved when select immune cells or immune-based pathways in the mammary microenvironment were inhibited. Treatment of mammary tumor-bearing mice with either a neutralizing mAb to colony-stimulating factor-1 (CSF-1) or a small-molecule inhibitor of the CSF-1 receptor kinase (i.e., PLX3397), resulting in efficient macrophage depletion, significantly delayed tumor regrowth following radiotherapy. Delayed tumor growth in this setting was associated with increased presence of CD8(+) T cells and reduced presence of CD4(+) T cells, the main source of the TH2 cytokine IL4 in mammary tumors. Selective depletion of CD4(+) T cells or neutralization of IL4 in combination with radiotherapy phenocopied results following macrophage depletion, whereas depletion of CD8(+) T cells abrogated improved response to radiotherapy following these therapies. Analogously, therapeutic neutralization of IL4 or IL13, or IL4 receptor alpha deficiency, in combination with the chemotherapy paclitaxel, resulted in slowed primary mammary tumor growth by CD8(+) T-cell-dependent mechanisms. These findings indicate that clinical responses to cytotoxic therapy in general can be improved by neutralizing dominant TH2-based programs driving protumorigenic and immune-suppressive pathways in mammary (breast) tumors to improve outcomes.

Isolation and optimization for affinity and biophysical characteristics of anti-CCL17 antibodies from the VH1-69 germline gene

CCL17 is a homeostatic chemokine associated with several human inflammatory pathologies. This makes CCL17 a potential point of intervention in inflammatory diseases. Using a Fab-pIX phage display system we were able to select antibodies that specifically bind to CCL17 and neutralize CCL17-mediated signaling. Many of the selected antibodies belong to the VH1-69 germline gene family. The VH1-69 germline gene is represented at a high frequency in the human antibody repertoire and is seen in the early immune response to a variety of pathogens. The heavy chain CDR2 of this germline gene is notably hydrophobic and can insert into hydrophobic pockets of antigens, providing much of the binding energy for these antibodies. Affinity maturation of our primary binders by light chain mutagenesis produced antibodies with sub-nanomolar affinities, with affinity improvements up to 100-fold. These were screened for non-specific protein-protein interactions as a filter for solubility. All of our high affinity antibodies were found to have high levels of non-specific protein-protein interactions. We speculated that this was due to the hydrophobicity within the germline heavy chain CDR1 and CDR2. To ameliorate this problem, we generated a phage display library for one of the clones, where the surface-exposed residues within H-CDR1 and H-CDR2 were randomized. High stringency panning of this library against human CCL17 resulted in further affinity improvement, along with reduction in protein-protein interaction in some new variants. In addition, we improved the cross-reactivity to cynomolgus CCL17. We demonstrate that affinity maturation through targeted libraries in the VH1-69 germline gene can improve both affinity and biophysical characteristics of antibodies derived from this gene scaffold.

Engagement of two distinct binding domains on CCL17 is required for signaling through CCR4 and establishment of localized inflammatory conditions in the lung

CCL17 (TARC) function can be completely abolished by mAbs that block either one of two distinct sites required for CCR4 signaling. This chemokine is elevated in sera of asthma patients and is responsible for establishing inflammatory sites through CCR4-mediated recruitment of immune cells. CCL17 shares the GPCR CCR4, with CCL22 (MDC) but these two chemokines differentially affect the immune response. To better understand chemokine mediated effects through CCR4, we have generated chimeric anti-mouse CCL17 surrogate antibodies that inhibit function of this ligand in vitro and in vivo. The affinities of the surrogate antibodies for CCL17 range from 685 pM for B225 to 4.9 nM for B202. One antibody, B202, also exhibits weak binding to CCL22 (KD∼2 µM) and no binding to CCL22 is detectable with the second antibody, B225. In vitro, both antibodies inhibit CCL17-mediated calcium mobilization, β-arrestin recruitment and chemotaxis; B202 can also partially inhibit CCL22-mediated β-arrestin recruitment. Both B202 and B225 antibodies neutralize CCL17 in vivo as demonstrated by reduction of methacholine-induced airway hyperreactivity in the A. fumigatus model of asthma. That both antibodies block CCL17 function but only B202 shows any inhibition of CCL22 function suggests that they bind CCL17 at different sites. Competition binding studies confirm that these two antibodies recognize unique epitopes that are non-overlapping despite the small size of CCL17. Taking into consideration the data from both the functional and binding studies, we propose that effective engagement of CCR4 by CCL17 involves two distinct binding domains and interaction with both is required for signaling.

Multiplex protein profiling of bronchoalveolar lavage in idiopathic pulmonary fibrosis and hypersensitivity pneumonitis

CONTEXT:

Idiopathic pulmonary fibrosis (IPF) and chronic hypersensitivity pneumonitis (HP) are diffuse parenchymal lung diseases characterized by a mixture of inflammation and fibrosis, leading to lung destruction and finally death.

AIMS:

The aim of this study was to compare different pathophysiological mechanisms, such as angiogenesis, coagulation, fibrosis, tissue repair, inflammation, epithelial damage, oxidative stress, and matrix remodeling, in both disorders using bronchoalveolar lavage (BAL).

METHODS:

At diagnosis, patients underwent bronchoscopy with BAL and were divided into three groups: Control (n = 10), HP (n = 11), and IPF (n = 11), based on multidisciplinary approach (clinical examination, radiology, and histology): Multiplex searchlight technology was used to analyze 25 proteins representative for different pathophysiological processes: Eotaxin, basic fibroblast growth factor (FGFb), fibronectin, hepatocyte growth factor (HGF), interleukine (IL)-8, IL-12p40, IL-17, IL-23, monocyte chemotactic protein (MCP-1), macrophage-derived chemokine (MDC), myeloperoxidase (MPO), matrix metalloproteinase (MMP)-8, MMP-9, active plasminogen activating inhibitor 1 (PAI-1), pulmonary activation regulated chemokine (PARC), placental growth factor (PlGF), protein-C, receptor for advanced glycation end products (RAGE), regulated on activation normal T cells expressed and secreted (RANTES), surfactant protein-C (SP-C), transforming growth factor-β1 (TGF-β1), tissue inhibitor of metalloproteinase-1 (TIMP-1), tissue factor, thymic stromal lymphopoietin (TSLP), and vascular endothelial growth factor (VEGF).

RESULTS:

All patients suffered from decreased pulmonary function and abnormal BAL cell differential compared with control. Protein levels were increased in both IPF and HP for MMP-8 (P = 0.022), MMP-9 (P = 0.0020), MCP-1 (P = 0.0006), MDC (P = 0.0048), IL-8 (P = 0.013), MPO (P = 0.019), and protein-C (P = 0.0087), whereas VEGF was decreased (P = 0.0003) compared with control. HGF was upregulated in HP (P = 0.0089) and active PAI-1 was upregulated (P = 0.019) in IPF compared with control. Differences in expression between IPF and HP were observed for IL-12p40 (P = 0.0093) and TGF-β1 (P = 0.0045).

CONCLUSIONS:

Using BAL, we demonstrated not only expected similarities but also important differences in both disorders, many related to the innate immunity. These findings provide new clues for further research in both disorders.

[Effects of thymosin alpha-1 on radiation-induced pneumonitis]

BACKGROUND AND OBJECTIVE

Radiation-induced lung injure is one of the major factors of limitation in radiotherapy for lung cancer. Whether the use of thymosin and radiotherapy simultaneously would increase the radiation-induced lung injure is unclear. The aim of this study is to evaluate the effects of thymosin alpha-1 on radiation induced pneumonitis in mice.

METHODS

Three groups of mice, control (C), radiation alone (RT), thymosin alpha-1 plus radiation (T+RT), were entered into the study. The weight and mortality of mice, pleural effusion, quantity of protein and cell count in the bronchoalvealar lavage (BAL) and pulmonary fibrosis score were evaluated as the outcome measures.

RESULTS

The mortality ratio of the T+RT and RT groups were 3/14, 2/10, respectively. The time of death were all in the 23-24 weeks after radiotherapy. There was no pleural effusion in the T+RT group other than 2/2 occurred in RT group. The quantity of protein, cell number and neutrophil number in the BAL and lung coefficient in mice of T+RT group were remarkably lower than that of RT group, but the BALF macrophages number was remarkably higher than that in RT group in the 8 weeks. The quantity of protein, cell number, neutrophil number and macrophages number in the BAL, lung coefficient, the scores of lung fibrosis in mice of T+RT group were significantly lower than that of RT group in the 24 weeks. All test data were lowest in mice of C group. And there was no obvious pulmonary fibrosis in the mice of C group.

CONCLUSIONS

Thymosin alpha-1 could relieve radiation-induced acute and late pulmonary injuries.

Alternatively activated alveolar macrophages in pulmonary fibrosis-mediator production and intracellular signal transduction

Activated macrophages have been characterized as M1 and M2 according to their inflammatory response pattern. Here we analyzed the M2 marker expression and intracellular signal transduction in the course of cytokine-driven differentiation. We found elevated spontaneous production of the chemokines CCL17, CCL18 and CCL22 and increased expression of CD206 by alveolar macrophages from patients with lung fibrosis. Stimulation of normal human AM with Th2 cytokines IL-4 and/or IL-10 in vitro revealed IL-4 as the most powerful inducer of M2-phenotype in AM and monocytes. Importantly, IL-10 enhanced IL-4-induced expression of CCL18 and IL-1RA in a synergistic fashion. IL-4/IL-10 stimulation induces a strong activation of STAT3 in AM from fibrosis patients. These results suggest an important role for M2 polarized AM in the pathogenesis of pulmonary fibrosis and indicate that both IL-4 and IL-10 account for human AM phenotype shift to M2, as seen in patients with fibrotic interstitial lung diseases.

Selective changes in the immune profile of tumor-draining lymph nodes after different neoadjuvant chemoradiation regimens for locally advanced cervical cancer

PURPOSE

To assess how neoadjuvant chemoradiation regimens modulate the immune system state in tumor-draining lymph nodes (TDLN), in the setting of advanced cervical cancer.

METHODS AND MATERIALS

Tumor-draining lymph nodes of patients undergoing chemotherapy only (nonirradiated, NI-TDLN) and chemoradiation with lower-dose (39.6 Gy, LD-TDLN) and higher-dose radiation (50 Gy, HD-TDLN) were analyzed by multicolor flow cytometry.

RESULTS

Enlarging our previous data, LD-TDLN showed features overall indicative of an enhanced antitumor response as compared with NI-TDLN, namely a significant Th1 and Tc1 polarization and a lower amount of the potent CD4(+)Foxp3(+)CD25(high) regulatory T cell (Treg) subset identified by neuropilin-1 expression. Conversely, compared with NI-TDLN, HD-TDLN showed features overall indicative of an impaired antitumor response, namely a significantly inverted CD4/CD8 cell ratio, a higher Nrp1(+)Treg frequency, and a higher frequency of CCR4(+)Treg, a Treg subset facilitated in migrating out from TDLN to suppress the immune response against distant cancer cells. Moreover, the Th1 and Tc1 polarization induced by LD radiation was lost, and there was an unfavorable tolerogenic/immunogenic dendritic cell ratio compared with LD-TDLN.

CONCLUSIONS

Even minor differences in radiation dose in neoadjuvant regimens for locally advanced cervical cancer are crucial for determining the balance between a tolerogenic and an efficacious antitumor immune response in TDLN. Because most of the anticancer immune response takes place in TDLN, the present findings also emphasize the importance of chemoradiation protocols in the context of immunotherapeutic trials.

Macrophage derived chemokine (CCL22), thymus and activation-regulated chemokine (CCL17), and CCR4 in idiopathic pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronically progressive interstitial lung disease of unknown etiology. Previously, we have demonstrated the selective upregulation of the macrophage-derived chemokine CCL22 and the thymus activation-regulated chemokine CCL17 among chemokines, in a rat model of radiation pneumonitis/pulmonary fibrosis and preliminarily observed an increase in bronchoalveolar (BAL) fluid CCL22 levels of IPF patients.

METHODS

We examined the expression of CCR4, a specific receptor for CCL22 and CCL17, in bronchoalveolar lavage (BAL) fluid cells, as well as the levels of CCL22 and CCL17, to elucidate their pathophysiological roles in pulmonary fibrosis. We also studied their immunohistochemical localization.

RESULTS

BAL fluid CCL22 and CCL17 levels were significantly higher in patients with IPF than those with collagen vascular diseases and healthy volunteers, and there was a significant correlation between the levels of CCL22 and CCL17 in patients with IPF. CCL22 levels in the BAL fluid did not correlate with the total cell numbers, alveolar lymphocytes, or macrophages in BAL fluid. However, the CCL22 levels significantly correlated with the numbers of CCR4-expressing alveolar macrophages. By immunohistochemical and immunofluorescence analysis, localization of CCL22 and CCR4 to CD68-positive alveolar macrophages as well as that of CCL17 to hyperplastic epithelial cells were shown. Clinically, CCL22 BAL fluid levels inversely correlated with DLco/VA values in IPF patients.

CONCLUSION

We speculated that locally overexpressed CCL22 may induce lung dysfunction through recruitment and activation of CCR4-positive alveolar macrophages.