The effect of smoking on tumor immunoediting: Friend or foe?

The recognition of smoking as an independent risk factor for lung cancer has become a widely accepted within the realm of respiratory medicine. The emergence of tumor immunotherapy has notably enhanced the prognosis for numerous late-stage cancer patients. Nevertheless, some studies have noted a tendency for lung cancer patients who smoke to derive greater benefit from immunotherapy. This observation has sparked increased interest in the interaction between smoking and the immune response to tumors in lung cancer. The concept of cancer immunoediting has shed light on the intricate and nuanced relationship between the immune system and tumors. Starting from the perspectives of immune surveillance, immune equilibrium, and immune evasion, this narrative review explores how smoking undermines the immune response against tumor cells and induces the generation of tumor neoantigens, and examines other behaviors that trigger tumor immune evasion. By elucidating these aspects, the review concludes that smoking is not conducive to tumor immunoediting.

T-helper cells and their cytokines in pathogenesis and treatment of asthma.

Prosperous advances in understanding the cellular and molecular mechanisms of chronic inflammation and airway remodeling in asthma have been made over the past several decades. Asthma is a chronic inflammatory disease of the airways characterized by reversible airway obstruction that is self-resolving or remits with treatment. Around half of asthma patients are "Type-2-high" asthma with overexpression of type 2 inflammatory pathways and elevated type 2 cytokines. When stimulated by allergens, airway epithelial cells secrete IL-25, IL-33, and TSLP to derive a Th2 immune response. First ILC2 followed by Th2 cells produces a series of cytokines such as IL-4, IL-5, and IL-13. TFH cells control IgE synthesis by secreting IL-4 to allergen-specific B cells. IL-5 promotes eosinophil inflammation, while IL-13 and IL-4 are involved in goblet cell metaplasia and bronchial hyperresponsiveness. Currently, "Type-2 low" asthma is defined as asthma with low levels of T2 biomarkers due to the lack of reliable biomarkers, which is associated with other Th cells. Th1 and Th17 are capable of producing cytokines that recruit neutrophils, such as IFN-γ and IL-17, to participate in the development of "Type-2-low" asthma. Precision medicine targeting Th cells and related cytokines is essential in the management of asthma aiming at the more appropriate patient selection and better treatment response. In this review, we sort out the pathogenesis of Th cells in asthma and summarize the therapeutic approaches involved as well as potential research directions.

How does cigarette smoking affect airway remodeling in asthmatics?

Asthma is a prevalent chronic airway inflammatory disease involving multiple cells, and the prolonged course of the disease can cause airway remodeling, resulting in irreversible or partial irreversible airflow limitation and persistent airway hyperresponsiveness (AHR) in asthmatics. Therefore, we must ascertain the factors that affect the occurrence and development of airway remodeling in asthmatics. Smokers are not uncommon in asthmatics. However, there is no systematic description of how smoking promotes airway remodeling in asthmatics. This narrative review summarizes the effects of smoking on airway remodeling in asthmatics, and the progress of the methods for evaluating airway remodeling.

Mycobacterium infection secondary to exogenous lipoid pneumonia caused by nasal drops: a case report and literature review.

BACKGROUND: Exogenous lipoid pneumonia (ELP) is a rare disease and its diagnosis is often mistaken or delayed. Secondary infection with rapidly growing non-tuberculous mycobacteria is a rare complication of lipoid pneumonia. CASE PRESENTATION: A 38-year-old man presented with fever, cough, sputum, chest tightness, and shortness of breath. He had a 2-year history of allergic rhinitis and used liquid paraffin-containing menthol nasal drops daily. A chest CT scan showed multiple patchy ground glass opacities with blurred borders in both lungs, which were located in the inner pulmonary field and distributed along the bronchi. His ambient air PO2 was 63 mmHg. The patient was diagnosed with ELP by CT-guided lung biopsy. The nasal drops were discontinued, and systemic glucocorticoids were administered. During treatment, the pulmonary lesions deteriorated, and bronchoalveolar lavage was performed during bronchoscopy. Additionally, Mycobacterium abscessus was detected in the lavage fluid. Upon detection of a secondary M. abscessus infection, glucocorticoids were gradually discontinued, and anti-M. abscessus treatment was implemented. The patient's symptoms rapidly ameliorated. After 11 months of anti-M. abscessus treatment, a repeat CT scan showed clear regression of the lung lesions. CONCLUSION: Routine microbiological examination of samples, including sputum or alveolar lavage fluid, is necessary for patients with diagnosed or suspected ELP.

Ibrutinib Exacerbates Bleomycin-Induced Pulmonary Fibrosis via Promoting Inflammation.

Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible lung disease with high mortality rate. The etiology is unknown and treatment choices are limited. Thus, there is great interest to investigate novel agents for IPF therapy. Ibrutinib, BTK, and ITK irreversible inhibitor is a FDA-approved small molecule for the clinical therapy of B cell lymphoma. Its role in pulmonary fibrosis remains unknown. In this study, we investigated the anti-fibrotic activity of ibrutinib. Strikingly, ibrutinib did not inhibit but exacerbated bleomycin-induced pulmonary fibrosis by increased epithelial cell apoptosis, and inflammation in the lung. The upregulated TGF-ß and EMT transformation also contributes to enhanced myofibroblast differentiation and ECM deposition. Our findings reveal the detrimental effects of ibrutinib against bleomycin-mediated fibrosis and added to the understanding of IPF pathogenesis.

TREM-2 serves as a negative immune regulator through Syk pathway in an IL-10 dependent manner in lung cancer.

During infection, triggering receptor expressed on myeloid cells-2 (TREM-2) restrains dendritic cells (DCs) and macrophages (MΦs) phagocytosis, as well as reduces pro-inflammatory cytokines release through DNAX-activation protein 12 (DAP12) signaling. However, the role of TREM-2 signaling in cancer has never been elucidated. In the current study, we found that TREM-2 was up-regulated on peripheral blood monocytes in tumor-bearing host. More TREM-2+DCs were detected in the lung of 3LL tumor-bearing mice. On the other hand, the level of TREM-2 on pulmonary MΦs positively correlated with the pathological staging of lung cancer. However, surgical or chemotherapeutic reduction of tumor burden led to the obvious decline of TREM-2. In vitro, TREM-2 expression of bone marrow (BM)-derived DCs and MΦs was induced by conditional medium (CM) containing the supernatant of 3LL cells. TREM-2+DCs from CM and/or tumor-bearing mice held altered phenotypes (CD80LowCD86LowMHCIILow) and impaired functions, such as, reduced interleukin (IL)-12 secretion, increased IL-10 production, and weakened ovalbumin (OVA)-endocytic capacity; also developed potent inhibitory effect on T cell proliferation that could be partially reversed by TREM-2 blockage. Moreover, spleen tyrosine kinase (Syk) inhibitor restrained IL-10 production of TREM-2+DC. Remarkably, IL-10 neutralizing antibody and Syk inhibitor both lowered the suppressive potential of TREM-2+DCs in T cell proliferation. Also, adoptive transfer of this TREM-2+DCs accelerated the tumor growth rather than jeopardized survival in lung cancer-bearing mice. In conclusion, these results indicate that TREM-2 might act as a negative immuno-regulatory molecule through Syk pathway in an IL-10 dependent manner and partially predicts prognosis in lung cancer patients.

HB-EGF-Promoted Airway Smooth Muscle Cells and Their Progenitor Migration Contribute to Airway Smooth Muscle Remodeling in Asthmatic Mouse.

The airway smooth muscle (ASM) cells' proliferation, migration, and their progenitor's migration are currently regarded as causative factors for ASM remodeling in asthma. Heparin-binding epidermal growth factor (HB-EGF), a potent mitogen and chemotactic factor, could promote ASM cell proliferation through MAPK pathways. In this study, we obtained primary ASM cells and their progenitors from C57BL/6 mice and went on to explore the role of HB-EGF in these cells migration and the underlying mechanisms. We found that recombinant HB-EGF (rHB-EGF) intratracheal instillation accelerated ASM layer thickening in an OVA-induced asthmatic mouse. Modified Boyden chamber assay revealed that rHB-EGF facilitate ASM cell migration in a dose-dependent manner and ASM cells from asthmatic mice had a greater migration ability than that from normal counterparts. rHB-EGF could stimulate the phosphorylation of ERK1/2 and p38 in ASM cells but further migration assay showed that only epidermal growth factor receptor inhibitor (AG1478) or p38 inhibitor (SB203580), but not ERK1/2 inhibitor (PD98059), could inhibit rHB-EGF-mediated ASM cells migration. Actin cytoskeleton experiments exhibited that rHB-EGF could cause actin stress fibers disassembly and focal adhesions formation of ASM cells through the activation of p38. Finally, airway instillation of rHB-EGF promoted the recruitment of bone marrow-derived smooth muscle progenitor cells, which were transferred via caudal vein, migrating into the airway from the circulation. These observations demonstrated that ASM remodeling in asthma might have resulted from HB-EGF-mediated ASM cells and their progenitor cells migration, via p38 MAPK-dependent actin cytoskeleton remodeling.

Mannose prevents acute lung injury through mannose receptor pathway and contributes to regulate PPARγ and TGF-ß1 level.

Mannose has been reported to prevent acute lung injury (ALI), and mannose receptor (MR) has been demonstrated to have a role. The rationale for this study is to characterize the mechanism by which mannose and MR prevent lipopolysaccharide (LPS)-induced ALI. Male ICR mice were pretreated mannose by intravenous injection 5 min before and 3 h after intratracheal instillation of LPS. Pathological changes, proinflammatory mediator, peroxisome proliferator activated receptor gamma (PPARγ), MR, and transforming growth factor ß1 (TGF-ß1) levels were determined. The RAW264.7 cells were pretreated with mannose and stimulated with LPS for 3 h. Proinflammatory mediator and TGF-ß1 in the culture media, PPARγ, MR, and TGF-ß1 expression in RAW 264.7 cells were measured. Mannose markedly attenuated the LPS-induced histological alterations and inhibited the production of proinflammatory mediator in mice and in RAW 264.7 cells. Mannose increased PPARγ and MR expression, and inhibited TGF-ß1 stimulated by LPS. Interestingly, competitive inhibition of MR with mannan was associated with elimination of the anti-inflammatory effects of mannose, and reversed effects of mannose of regulation to PPARγ and TGF-ß1. MR is important in increasing PPARγ and decreasing TGF-ß1 expression and plays a critical role in mannose's protection against ALI.

IL-17A, but not IL-17F, is indispensable for airway vascular remodeling induced by exaggerated Th17 cell responses in prolonged ovalbumin-challenged mice.

We previously demonstrated an essential role of Th17 cells in excessive mucous secretion and airway smooth muscle proliferation in a prolonged OVA-challenged C57BL/6 mouse model. However, the impact of Th17 cells in vascular remodeling, another characteristic feature of airway remodeling in asthma, remains elusive. This issue was further investigated in this study. The time-course experiments showed that progressively increasing levels of Th17 cells and IL-17A (not IL-17F) in the lungs of prolonged allergen-challenged mice were positively correlated with microvessel density in peribronchial tissues. In addition, exaggerated airway vascular remodeling in this mouse model was exacerbated by airway administration of IL-17A or adoptive transfer of Th17 cells. This effect was dramatically alleviated by the administration of anti-IL-17A Ab, but not anti-IL-17F Ab. Boyden chamber assays indicated that IL-17A accelerates endothelial progenitor cell (EPC) migration. Furthermore, EPC accumulation in the airways of allergen-exposed mice after adoptive transfer of Th17 cells was eliminated by blockade of IL-17A. We found that IL-17A promoted tubule-like formation rather than proliferation of pulmonary microvascular endothelia cells (PMVECs) in vitro. In addition, IL-17A induced PMVEC tube formation via the PI3K/AKT1 pathway, and suppression of the PI3K pathway markedly reduced the formation of tubule-like structures. Collectively, our results indicate that Th17 cells contribute to the airway vascular remodeling in asthma by mediating EPC chemotaxis, as well as PMVEC tube formation, via IL-17A rather than IL-17F.

Treg/Th17 imbalance in malignant pleural effusion partially predicts poor prognosis.

Accumulating evidence shows that an imbalance in regulatory T cells (Tregs)/T helper IL-17-producing cells (Th17) exists in malignant pleural effusion (MPE). However, the cause of this phenomenon in MPE and the underlying mechanism remain uncertain. The percentages of Tregs and Th17 cells in MPE and parapneumonic effusion (PPE) were determined by flow cytometry. Their specific transcription factors, forkhead box P3 (FoxP3) and retinoic acid-related orphan receptor γt (RORγt); related cytokines, interleukin-6 (IL-6), IL-17, IL-10, and transforming growth factor-ß1 (TGF­ß1); and chemokines, C-C motif ligand 17 (CCL17) and CCL20, were analyzed by real-time PCR and ELISA, respectively. Compared to patients with PPE, patients with MPE presented a higher percentage of Tregs but a lower frequency of Th17 cells. Foxp3 mRNA expression level in the cells in the pleural effusion was significantly increased in patients with MPE compared to the levels in patients with PPE (MPE vs. PPE: 3.05±0.62 vs. 0.52±0.11, p=0.0012). It was also noted that high levels of IL-10, TGF-ß1 and CCL17 were observed in MPE when compared to PPE (MPE vs. PPE: IL-10, 166.3±39.53 vs. 40.38±10.92 pg/ml, p=0.0307; TGF-ß1, 10,720±1,274 vs. 1,747±293.2 pg/ml, p<0.0001; CCL17, 341.1±88.22 vs. 119.2±19.80 pg/ml, p=0.0427). Furthermore, a high ratio of Tregs/Th17 cells in MPE was highly correlated to poor survival. An alteration in CCL17 and CCL20 might contribute to the Treg/Th17 imbalance in MPE, which partially predicts a poor prognosis in patients with lung cancer.

Relationship of redundant Th17 cells and IL-17A, but not IL-17 F, with the severity of obstructive sleep apnoea/hypopnoea syndrome (OSAHS).

BACKGROUND: The pathogenesis of obstructive sleep apnoea/hypopnoea syndrome (OSAHS), a highly prevalent disease, is not completely understood. The purpose of this study was to investigate the contributions of Th17 cells and the Th17-associated cytokines IL-17A and IL-17 F to OSAHS. METHODS: 46 male patients with a clinical suspicion of OSAHS were enrolled and divided into four groups based on their polysomnography results: controls and mild, moderate, and severe OSAHS. The serum levels of IL-17A and IL-17 F were determined by enzyme linked immunosorbent assay (ELISA), pulmonary arterial pressure (PAP) was determined by echocardiography, and Th17 cell frequencies in peripheral blood were measured by flow cytometry. RESULTS: Serum IL-17A levels in the severe group were elevated (median value: control group 0.89 pg/ml, mild OSAHS 1.02 pg/ml, moderate OSAHS 1.18 pg/ml, and severe OSAHS 1.62 pg/ml; p < 0.05) and positively correlated with AHI (r = 0.52, p < 0.05) but negatively related to the mean O2 saturation and lowest O2 saturation (r = -0.349, p < 0.05; and r = -0.336, p < 0.05, respectively). Although the frequencies of Th17 cells in the OSAHS groups were higher than that in the control group, these differences were not significant (p = 0.275). Pulmonary arterial hypertension was not present in our patients as the median PAP of the normal control and the mild, moderate, and severe OSAHS groups were 26, 27.5, 24.5, and 25.5 mmHg, respectively (p = 0.676). CONCLUSION: IL-17A may be involved in the pathogenesis of OSAHS and may represent a target for therapeutic intervention.

The transmembrane protein 16A Ca(2+)-activated Cl- channel in airway smooth muscle contributes to airway hyperresponsiveness.

RATIONALE: Asthma is a chronic inflammatory disorder with a characteristic of airway hyperresponsiveness (AHR). Ca(2+)-activated Cl(-) [Cl((Ca))] channels are inferred to be involved in AHR, yet their molecular nature and the cell type they act within to mediate this response remain unknown. OBJECTIVES: Transmembrane protein 16A (TMEM16A) and TMEM16B are Cl((Ca)) channels, and activation of Cl((Ca)) channels in airway smooth muscle (ASM) contributes to agonist-induced airway contraction. We hypothesized that Tmem16a and/or Tmem16b encode Cl((Ca)) channels in ASM and mediate AHR. METHODS: We assessed the expression of the TMEM16 family, and the effects of niflumic acid and benzbromarone on AHR and airway contraction, in an ovalbumin-sensitized mouse model of chronic asthma. We also cloned TMEM16A from ASM and examined the Cl(-) currents it produced in HEK293 cells. We further studied the impacts of TMEM16A deletion on Ca(2+) agonist-induced cell shortening, and on Cl((Ca)) currents activated by Ca(2+) sparks (localized, short-lived Ca(2+) transients due to the opening of ryanodine receptors) in mouse ASM cells. MEASUREMENTS AND MAIN RESULTS: TMEM16A, but not TMEM16B, is expressed in ASM cells and its expression in these cells is up-regulated in ovalbumin-sensitized mice. Niflumic acid and benzbromarone prevent AHR and contraction evoked by methacholine in ovalbumin-sensitized mice. TMEM16A produces Cl((Ca)) currents with kinetics similar to native Cl((Ca)) currents. TMEM16A deletion renders Ca(2+) sparks unable to activate Cl((Ca)) currents, and weakens caffeine- and methacholine-induced cell shortening. CONCLUSIONS: Tmem16a encodes Cl((Ca)) channels in ASM and contributes to Ca(2+) agonist-induced contraction. In addition, up-regulation of TMEM16A and its augmented activation contribute to AHR in an ovalbumin-sensitized mouse model of chronic asthma. TMEM16A may represent a potential therapeutic target for asthma.

Imbalance of Th17/Treg cells in mice with chronic cigarette smoke exposure.

BACKGROUND: Recent studies have revealed that autoimmune responses mediated by CD4(+) T cells may contribute to the development of chronic obstructive pulmonary disease (COPD). Meanwhile, imbalance of Th17/Treg has been reported to play a key role in the pathogenesis of autoimmune diseases. However, information on Th17/Treg balance in COPD is relatively limited. METHOD: We established a mouse model of COPD induced by chronic cigarette smoke (CS) exposure. Th17 and Treg in lung tissue and peripheral blood were quantified by flow cytometry. The level of the specific transcription factors of both T cell subsets in lung tissue was determined by real-time PCR. The expressions of Th17- and Treg-related cytokines in serum and bronchoalveolar lavage fluid (BALF) were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: We found that mice with chronic CS exposure showed significant increase in lung Th17 prevalence, retinoic acid orphan receptor (ROR)-γt mRNA and Th17-related cytokines (IL-17A, IL-6 and IL-23). Meanwhile, there was obvious decrease in Treg cell prevalence, Forkhead box (Fox) p3 mRNA and Treg-related cytokine IL-10, as compared to mice underwent sub-acute CS exposure and air-exposure. Similar tendency was also found for the Th17/Treg ratio in peripheral blood. CONCLUSIONS: Our study thus reveals that the Th17/Treg imbalance exists in mice with chronic CS exposure, suggesting its potential role in the breakdown of immune self-tolerance in COPD. Further research on regulation of Th17/Treg balance may provide insights into the development of new therapeutic targets for this disease.

Low doses of exogenous interferon-γ attenuated airway inflammation through enhancing Fas/FasL-induced CD4+ T cell apoptosis in a mouse asthma model.

To investigate whether low doses of exogenous interferon (IFN)-γ attenuate airway inflammation, and the underlying mechanisms, in asthma. C57BL/6 mice (n=42), after intraperitoneal ovalbumin (OVA) sensitization on day 0 and day 12, were challenged with OVA aerosol for 6 consecutive days. Different doses of IFN-γ were then administered intraperitoneally 5 min before each inhalation during OVA challenge. Airway hyperresponsiveness, airway inflammatory cells, cytokine profiles, and Fas/FasL expression on CD4(+) T cells were evaluated in an asthma model. The effect of various IFN-γ doses on Fas/FasL expression and CD4(+) T cell apoptosis were assessed in vitro. We demonstrated that low doses of IFN-γ reduced pulmonary infiltration of inflammatory cells, Th2 cytokine production, and goblet cells hyperplasia (P<0.05), while high doses of endogenous IFN-γ had almost no effect. We also found that low doses of IFN-γ relocated Fas/FasL to the CD4(+) T cell surface in the asthma model (P<0.05) and increased FasL-induced apoptosis in vitro (P<0.05). Furthermore, treatment with MFL-3, an anti-FasL antibody, partially abolished the anti- inflammatory properties of IFN-γ in the airway rather than affecting the Th1/Th2 balance. This research has revealed an alternative mechanism in asthma that involves low doses of IFN-γ, which attenuate airway inflammation through enhancing Fas/FasL-induced CD4(+) T cell apoptosis.

[Preventive effect of IL-18 gene modified mature dendritic cells vaccine on airway inflammation in mouse asthma model].

OBJECTIVE: To investigate the preventive effect of interleukin-18 (IL-18) gene modified mature dendritic cells (mDC) vaccine on airway inflammation in mouse asthma model. METHODS: The asthma model was induced by injection of ovalbumin (OVA) in BALB/c mice. IL-18 gene modified mouse mature dendritic cells (mDC) were detected by flow cytometry and its capacity of inducing allogeneic T cell responses was examined by mixed lymphocyte reaction (MLR). The OVA-induced asthmatic mice were randomly divided into 6 groups: PBS group, DXM group, mDC group, Ad-LacZ-mDC group, Ad-IL-18-mDC group and control group. The pathological changes in lung tissues were assayed by HE and AB-PAS staining. The numbers of inflammatory cells and percentage of eosinophils (EOS) in bronchoalveolar lavage fluid (BALF) were counted. The levels of IFN-γ IL-4 and IL-13 in culture supernatant of splenocytes were measured by ELISA method. The percentage of CD4(+)CD25(+)Foxp3(+) Treg was assessed by flow cytometry analysis. RESULT: The vaccine was effective in decreasing the infiltration of EOS and accumulation of airway goblet cells in lung tissues, the numbers of inflammatory cells and percentage of EOS in BALF, and the levels of IL-4 and IL-13 in culture supernatant of splenocytes, and in increasing the levels of IFN-γ in culture supernatant of splenocytes and the percentage of CD4(+)CD25(+)foxP3(+) reg. CONCLUSION: IL-18 gene modified mDC vaccine has a preventive effect on airway inflammation in OVA-induced asthmatic mice.

The overexpression of heparin-binding epidermal growth factor is responsible for Th17-induced airway remodeling in an experimental asthma model.

Th17 cells that produce IL-17 have been found to participate in the development of allergy-triggered asthma. However, whether they play a causative role in the pathogenesis of airway remodeling in chronic asthma remains unclear. In this study, we investigated the role of Th17 cells in airway remodeling and the possible involvement of epidermal growth factor (EGF) receptor signals downstream of Th17. We established a C57BL/6 mouse model of prolonged allergen challenge that exhibits many characteristics of airway remodeling. Prolonged allergen challenge induced a progressive increase in the number of airway-infiltrating Th17 cells, and Th17 counts positively correlated with the severity of airway remodeling. Increases in mucus production, airway smooth muscle (ASM) mass, peribronchial collagen deposition, and airway heparin-binding EGF (HB-EGF) expression have been observed in sensitized mice following prolonged allergen exposure or adoptive Th17 transfer; remarkably, these effects can be abrogated by treatment with anti-IL-17 mAb. Both the EFGR inhibitor AG1478 and an anti-HB-EGF mAb ameliorated all of these effects, except for peribronchial collagen deposition in the presence of high levels of IL-17. In vitro, Th17 cells enhanced the airway epithelial expression of HB-EGF in a coculture of the two cells. The conditioned medium obtained from this coculture system effectively promoted ASM proliferation; this response was dramatically abolished by anti-HB-EGF mAb but not Abs against other EGF receptor ligands or IL-17. These observations demonstrated that overexpression of airway HB-EGF induced by IL-17 secreted from redundant expanding Th17 cells might contribute to excessive mucus expression and ASM proliferation in chronic asthma.

Prolonged ovalbumin challenge facilitates Th17 polarization in sensitized mice.

OBJECTIVE AND DESIGN: In this study, we explored whether prolonged ovalbumin (OVA) exposure in sensitized mice created an environment suitable for Th17 differentiation. MATERIALS AND METHODS: BALB/c and C57BL/6 mice (n = 36), after intraperitoneal OVA sensitization on days 0 and 12, received prolonged OVA aerosol challenges up to day 55. Airway inflammatory cell levels, cytokine profiles, and Th17 cell infiltration were evaluated after sacrifice. RESULTS: Prolonged OVA challenge caused inflammation that was characterized by raised influxes of airway macrophages and neutrophils. Following long-term exposure, Th17 cytokines and Th17 cell numbers progressively increased in the lung (P < 0.05) along with increased production of Th17 polarization-related factors, including TGF-beta, IL-6, and IL-23. The lineage-specific transcription factor for Th17 subsets, RORgammat, displayed similar upregulation throughout the OVA challenge (P < 0.05). CONCLUSIONS: Prolonged OVA challenge induces an environment that facilitates Th17 polarization.

Cancer-expanded myeloid-derived suppressor cells induce anergy of NK cells through membrane-bound TGF-beta 1.

NK cells, the important effector of innate immunity, play critical roles in the antitumor immunity. Myeloid-derived suppressor cells (MDSC), a population of CD11b(+)Gr-1(+) myeloid cells expanded dramatically during tumor progression, can inhibit T cells and dendritic cells, contributing to tumor immune escape. However, regulation of NK cell innate function by MDSC in tumor-bearing host needs to be investigated. In this study, we found that the function of NK cells from liver and spleen was impaired significantly in all tumor-bearing models, indicating the impairment of hepatic NK cell function by tumor is a universal phenomenon. Then we prepared the orthotopic liver cancer-bearing mice as tumor model to investigate how hepatic NK cells are impaired. We show that down-regulation of NK cell function is inversely correlated with the marked increase of MDSC in liver and spleen. MDSC inhibit cytotoxicity, NKG2D expression, and IFN-gamma production of NK cells both in vitro and in vivo. After incubation with MDSC, NK cells could not be activated to produce IFN-gamma. Furthermore, membrane-bound TGF-beta1 on MDSC is responsible for MDSC-mediated suppression of NK cells. The impaired function of hepatic NK cells in orthotopic liver cancer-bearing mice could be restored by depletion of MDSC, but not regulatory T cells. Therefore, cancer-expanded MDSC can induce anergy of NK cells via membrane-bound TGF-beta1. MDSC, but not regulatory T cells, are main negative regulator of hepatic NK cell function in tumor-bearing host. Our study provides new mechanistic explanations for tumor immune escape.

Gastric mucosal injury due to hemorrhagic reperfusion and efficacy of Salvia miltiorrhizae extract F and cimetidine.

AIM: To observe the gastric mucosal injury caused by hemorrhagic shock and reperfusion and to compare the effect between Salvia miltiorrhizae extract F (SEF) and cimetidine (CI) on it. METHODS: A model of hemorrhage/reperfusion injury was produced by Itoh method. Wistar rats were randomly divided into three groups: 0.9% sodium chloride treatment group (NS group), SEF treatment group (SEF group), and CI treatment group (CI group). Saline, SEF and CI were injected respectively. The index of gastric mucosal lesions (IGML) was expressed as the percentage of lesion area in the gastric mucosa. The degree of gastric mucosal lesions was categorized into grades 0, 1, 2, 3. Atom absorption method was used to measure the intracellular calcium content. Radioimmunoassay was used to measure the concentrations of prostaglandins. RESULTS: IGML (%) and grade 3 (%) were 23.18+/-6.82, 58.44+/-9.07 in NS group, 4.42+/-1.39, 20.32+/-6.95 in SEF group and 3.74+/-1.56, 23.12+/-5.09 in CI group, and the above parameters in SEF group and CI group decreased significantly (IGML: SEF vs NS, t = 6.712, P = 0.000<0.01; CI vs NS, t = 6.943, P = 0.000<0.01; grade 3: SEF vs NS, t = 8.386, P = 0.000; CI vs NS, t = 8.411, P = 0.000), but the grade 0 and grade 1 damage in SEF group (22.05+/-5.96, 34.12+/-8.12) and CI group (18.54+/-4.82, 30.15+/-7.12) were markedly higher than those in NS group (3.01+/-1.01, 8.35+/-1.95; grade 0: SEF vs NS, t = 8.434, P = 0.000<0.01; CI vs NS, t = 7.950, P = 0.000<0.01; grade 1: SEF vs NS, t = 8.422, P = 0.000<0.01; CI vs NS, t = 8.448, P = 0.000<0.01). The intracellular calcium content (microg/mg) in SEF group (0.104+/-0.015) and CI group (0.102+/-0.010) was markedly lower than that in NS group (0.131+/-0.019, SEF vs NS, t = 2.463, P = 0.038<0.05; CI vs NS, t = 3.056, P = 0.017<0.05). The levels (pg/mg) of PGE(2), 6-keto-PGF(1alpha) and 6-keto-PGF(1alpha)/TXB(2) were 540+/-183, 714+/-124, 17.38+/-5.93 in NS group and 581+/-168, 737+/-102, 19.04+/-8.03 in CI group, 760+/-192, 1 248+/-158, 33.42+/-9.24 in SEF group, and the above parameters in SEF group markedly raised (PGE(2): SEF vs NS, t = 2.282, P = 0.046<0.05; SEF vs CI, t = 2.265, P = 0.047<0.05; 6-keto-PGF(1alpha): SEF vs NS, t = 6.583, P = 0.000<0.000; SEF vs CI, t = 6.708, P = 0.000<0.01; 6-keto-PGF(1alpha)/TXB(2): SEF vs NS, t = 3.963, P = 0.003<0.001; SEF vs CI, t = 3.243, P = 0.009<0.01), whereas TXB(2) level in SEF group (45.37+/-7.54) was obviously lower than that in NS group (58.28+/-6.74, t = 3.086, P = 0.014<0.05) and CI group (54.32+/-6.89, t = 2.265, P = 0.047<0.05). No significant difference was shown between NS group and CI group (PGE(2): t = 0.414, P = 0.688>0.05; 6-keto-PGF(1alpha): t = 0.310, P = 0.763>0.05; TXB(2): t = 1.099, P = 0.298>0.05; 6-keto-PGF(1alpha)/TXB(2): t = 0.372, P = 0.718>0.05). CONCLUSION: Both SEF and CI could inhibit reperfusion-induced injury in gastric mucosa, but with different mechanisms. SEF could not only enhance the protective effect of gastric mucosa, but also abate the injury factors, while CI can only abate the injury factors.

[The effect of a mouse IL-12 plasmid on airway inflammation and cytokine production in a mouse asthmatic model].

OBJECTIVE: To investigate the effect of a mouse IL-12 gene expressive plasmid (mIL-12 plasmid) on the airway inflammation and the cytokine production in asthmatic mice and to study the possible mechanisms. METHODS: A mouse model of asthma was established by sensitization with ovalbumin (OVA). Forty-one BALB/c mice were divided into six groups including an asthmatic model group (group A, eight mice, sensitized with OVA plus challenging with OVA by aerosol), a model control group (group B, six mice, sensitized with OVA plus aerosolizing with normal saline), a mIL-12 plasmid prevention group (group C, eight mice, receiving intramuscularly mIL-12 plasmid 100 micro g on day 1, day 3, and day 5), a mIL-12 plasmid treatment group (group D, eight mice, receiving intramuscularly mIL-12 plasmid 100 micro g on day 14, day 16, and day 18), an empty plasmid prevention group (group E, five mice, receiving intramuscularly empty plasmid 100 micro g on day 1, day 3, and day 5), and an empty plasmid treatment group (group F, six mice, receiving intramuscularly empty plasmid 100 micro g on day 14, day 16 and day 18). The number of EOS and the concentration of IL-4, IL-5 and IFN-gamma in the mouse bronchoalveolar lavage fluids (BALF) were detected. RESULTS: The number of EOS and the concentration of IL-4, IL-5 and IFN-gamma from group B were (0.01 +/- 0.03) x 10(8)/L, (24 +/- 4) pg/ml, (33 +/- 6) pg/ml, (725 +/- 59) pg/ml,respectively; those from group C were (0.06 +/- 0.04) x 10(8)/L, (43 +/- 13) pg/ml, (63 +/- 10) pg/ml, (626 +/- 60) pg/ml, respectively, and those from group D were (0.11 +/- 0.12) x 10(8)/L, (38 +/- 14) pg/ml, (66 +/- 14) pg/ml, (661 +/- 40) pg/ml, respectively; the difference was significant as compared with those from group A [(2.97 +/- 1.20) x 10(8)/L, (122 +/- 45) pg/ml, (126 +/- 34) pg/ml, and (435 +/- 49) pg/ml] (P < 0.001). The number of EOS and the concentration of IL-4, IL-5 and IFN-gamma from group C and group D also showed significant difference in comparison with those from group E [(1.96 +/- 0.93) x 10(8)/L, (110 +/- 24) pg/ml, (112 +/- 11) pg/ml and (464 +/- 51) pg/ml], and group F [(2.11 +/- 0.90) x 10(8)/L, (88 +/- 17) pg/ml, (107 +/- 6) pg/ml and (481 +/- 64) pg/ml] (P < 0.01). CONCLUSION: The mIL-12 plasmid can significantly inhibit airway inflammation. Its regulatory effect on the balancing of Th1/Th2 cytokines may be a possible mechanism.