The efficacy and safety of selective RET inhibitors in RET fusion-positive non-small cell lung cancer: a meta-analysis.

BACKGROUND: Rearranged during transfection (RET) fusion-positive occurs in approximately 2% of non-small cell lung cancer (NSCLC). This mutation often predicts metastasis risk and poor prognosis, and current mainstream therapies provide limited patient benefit. Selective RET inhibitors Pralsetinib and Selpercatinib are targeted drugs approved by the US Food and Drug Administration for treating RET-mutated tumors. The phase I/II clinical trial results of their treatment of NSCLC have been published. However, the clinical effect of selective RET inhibitors on RET fusion-positive NSCLC remains controversial. Purpose Meta-analysis was performed to investigate the efficacy and safety of selective RET inhibitors in treating RET fusion-positive NSCLC. Methods Qualified literature was searched in Pubmed, Cochrane Library, Embase, and Web of Science. Outcomes included objective response rate (ORR), median progression-free survival (mPFS), disease control rate (DCR), intracranial ORR, and adverse events. Stata 15.1 software was used to analyze the data. Results A total of 8 studies were included in this meta-analysis. The combined results showed that the ORR of patients treated with selective RET inhibitors was 67% (95% confidence interval:0.64 to 0.70, P < 0.01), DCR was 92% (95%CI: 0.91-0.94, P < 0.01), the mPFS was 16.09 months (95%CI: 11.66-20.52, P < 0.01). In treated patients with RET mutation, the intracranial ORR was 86% (95%CI:0.74 ~ 0.96, P < 0.01). ORR in untreated patients was more effective than untreated patients [HR = 0.44 (95%CI: 0.35-0.56, P < 0.01)]. The major adverse events (grade 3-4) are neutropenia (13%) and anaemia (13%). Conclusions Selective RET inhibitors Pralsetinib and Selpercatinib have shown a good effect on RET fusion-positive NSCLC, with a low incidence of adverse events.

IL-27 mediates anti-inflammatory effect in cigarette smoke induced emphysema by negatively regulating IFN-γ producing cytotoxic CD8+ T cells in mice.

Chronic airway inflammation mediated by CD8+ T lymphocytes contributes to the pathogenesis of Chronic obstructive pulmonary disease (COPD). Deciphering the fingerprint of the chronic inflammation orchestrated by CD8+ T cells may allow the development of novel approaches to COPD management. Here, the expression of IL-27 and IFN-γ+ CD8+ Tc1 cells were evaluated in patients with COPD and in cigarette smoke-exposed mice. The production of IL-27 by marrow-derived dendritic cells (mDCs) in response to cigarette smoke extract (CSE) was assessed. The role of IL-27 in IFN-γ+ CD8+ Tc1 cells was explored. We demonstrated that elevated IL-27 was accompanied by an exaggerated IFN-γ+ CD8+ Tc1 response in a smoking mouse model of emphysema. We noted that lung dendritic cells were one of the main sources of IL-27 during chronic cigarette smoke exposure. Moreover, CSE directly induced the production of IL-27 by mDCs in vitro. IL-27 negatively regulated the differentiation of IFN-γ+ CD8+ Tc1 cells isolated from cigarette smoke-exposed mice in a STAT1- and STAT3-independent manner. Systemic administration of recombinant IL-27 attenuated IFN-γ+ CD8+ Tc1 response in the late phase of cigarette smoke exposure. Our results uncovered that IL-27 negatively regulates IFN-γ+ CD8+ Tc1 response in the late stage of chronic cigarette smoke exposure, which may provide a new strategy for the anti-inflammatory treatment of smoking-related COPD/emphysema.

Retrospective Analysis of 9 Cases of Primary Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma and Literature Review.

BACKGROUND Primary pulmonary mucosa-associated lymphoma tissue lymphoma is rare and is often misdiagnosed because of its diverse and nonspecific clinical features. The aim of this study was to raise awareness among clinicians and to share our experience of treating and managing such patients. MATERIAL AND METHODS This retrospective study was conducted between 1 January 2009 and 31 October 2017 at the First Affiliated Hospital of Guangxi Medical University. All cases were confirmed via pathology and immunohistochemistry. In addition, we reviewed all relevant literature. RESULTS Altogether, 21 patients (7 female, 14 male) with a median age of 54 (range, 19-84) years were diagnosed with primary pulmonary mucosa-associated lymphoma. Expiratory dyspnea, repeated cough and expectoration, and weight loss were the most common symptoms. Pulmonary lesions were found via physical examination in 10 patients who had no obvious symptoms. Chest computed tomography showed nodules, pulmonary consolidation, bronchial bronchogram, ground-glass opacity, and mediastinal lymph node enlargement. Some patients were misdiagnosed with tuberculosis and pneumonia, while others were initially diagnosed with cancer. Tumor pathology and immunocytochemistry indicated primary pulmonary mucosa-associated lymphoma tissue lymphoma. Six patients underwent chemotherapy, 5 underwent surgery, 4 underwent surgery and chemotherapy, 3 were only observed, and 3 refused treatment. CONCLUSIONS The development of primary pulmonary mucosa-associated lymphoid tissue lymphoma is slow and insidious. Having no specific clinical symptoms and imaging findings, it is easily misdiagnosed. Final diagnosis is made via pathologic evaluation and immunohistochemistry. Surgery and chemotherapy are the primary treatment modalities and yield a good prognosis.

Enhanced activation of circulating plasmacytoid dendritic cells in patients with Chronic Obstructive Pulmonary Disease and experimental smoking-induced emphysema.

Plasmacytoid dendritic cells (pDCs) are key cells bridging the innate with adaptive immunity. However, the phenotypic characteristics of circulating pDCs and its role in smoking related-Chronic Obstructive Pulmonary Disease (COPD) remain largely unknown. The aim of this study was analyzed the phenotype of circulating pDCs and the expression of IFN-γ producing CD8+T cells and IL-17-producing CD8+T cells in patients with COPD by using multi-colour flow cytometry. The cytokine profiles in peripheral blood from all subjects were measured by ELISA. The influence of cigarette smoke on pDCs was evaluated in an experimental mouse model of emphysema. Circulating pDCs in patients with COPD and in mice exposed to cigarette smoke expressed high levels of co-stimulatory molecules CD40 or CD86 accompanied by exaggerated IFN-γ producing CD8+T cells and IL-17-producing CD8+T cells. In vitro, cigarette smoke directly promoted pDCs maturation and release of IFN-α, IL-6 and IL-12, subsequently inducing differentiation of IFN-γ producing CD8+T cells and IL-17-producing CD8+T cells from mouse naïve CD8+T cells. These data suggested that circulating pDCs display an enhanced activation phenotype in patients with COPD and in experimental smoking mouse model of emphysema, which might contribute to exaggerated IFN-γ producing CD8+T and IL-17-producing CD8+T cell-mediated immune responses.

Cigarette Smoke Induction of Interleukin-27/WSX-1 Regulates the Differentiation of Th1 and Th17 Cells in a Smoking Mouse Model of Emphysema.

IFN-γ-producing CD4+ T (Th1) cells and IL-17-producing CD4+ T (Th17) cells play a critical role in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the immune regulation between Th1 and Th17 cells remains unclear. Previous studies have demonstrated that interleukin-27 (IL-27)/WSX-1 exerted pro- or anti-inflammatory effects in many acute inflammatory diseases by modulating T cell-mediated immune response, but little was known about its role in chronic inflammatory disease, especially in smoking-related lung diseases. Considering IL-27 is an important regulator in T lymphocytes immune responses and was found markedly increased in patients with COPD, we hypothesized that IL-27/WSX-1 may exert immuno-regulatory effects on the differentiation of Th1 and Th17 cells in smoking-related COPD. In this study, we aimed to evaluate the expression of IL-27 in patients with COPD and explore the role of IL-27/WSX-1 on Th1 and Th17 cells differentiation in a smoking mouse model of emphysema. We found that elevated expression of IL-27 was associated with increased proportion of Th1 cells and Th17 cells in patients with COPD and demonstrated parallel findings in cigarette smoke-exposed mice. In addition, cigarette smoke exposure upregulated the expression of IL-27R (WSX-1) by naive CD4+ T cells in mice. In vitro, IL-27 significantly augmented the secretion of IFN-γ by naive CD4+ T cells via a T-bet, p-STAT1, and p-STAT3-dependent manner, but inhibited the production of IL-17 by a ROR-γt and p-STAT1-dependent way. Furthermore, anti-IL27 treatment dramatically decreased the expression of IFN-γ-producing CD4+ T cells in cigarette smoke-exposed mice. These findings proposed that IL-27 has functions for promoting the expression of Th1 cells but inhibiting the expression of Th17 cells in vitro and IL-27 neutralization-attenuated Th1-mediated inflammation in vivo, suggesting targeting IL-27/WSX-1 may provide a new therapeutic approach for smoking-related COPD.

Infiltration of IL-17-Producing T Cells and Treg Cells in a Mouse Model of Smoke-Induced Emphysema.

Chronic obstructive pulmonary disease (COPD) is a progressive and irreversible chronic inflammatory disease associated with the accumulation of activated T cells. To date, there is little information concerning the intrinsic association among Th17, Tc17, and regulatory T (Treg) cells in COPD. The objective of this study was to investigate the variation of lungs CD4(+)Foxp3(+) Treg cells and IL-17-producing CD4 and CD8 (Th17 and Tc17) lymphocytes in mice with cigarette-induced emphysema. Groups of mice were exposed to cigarette smoke or room air. At weeks 12 and 24, mice were sacrificed to observe histological changes by HE stain. The frequencies of Th17 (CD4(+)IL-17(+)T), Tc17 (CD8(+)IL-17(+)T), and Treg (CD4(+)Foxp3(+)T) cells in lungs from these mice were analyzed by flow cytometry. The mRNA levels of orphan nuclear receptor ROR γt and Foxp3 were performed by real-time quantitative polymerase chain reaction. The protein levels of interleukin-17 (IL-17), IL-6, IL-10, and transforming growth factor-beta (TGF-ß1) were measured by enzyme-linked immunosorbent assay. Cigarette smoke caused substantial enlargement of the air spaces accompanied by the destruction of the normal alveolar architecture and led to emphysema. The frequencies of Th17 and Tc17 cells, as well as the expressions of IL-6, IL-17, TGF-ß1, and ROR γt were greater in the lungs of cigarette smoke (CS)-exposed mice, particularly in the 24-week CS-exposed mice. The frequencies of Treg cells and the expressions of IL-10 and Foxp3 were lower in CS-exposed mice compared to control group. More important, the frequencies of Tregs were negatively correlated with Th17 cells and with Tc17 cells. Interestingly, a significant portion of the cells that infiltrate the lungs was skewed towards a Tc17 phenotype. Our findings suggest the contribution of Th17, Tc17, and Treg cells in the pathogenesis of COPD. Rebalance of these cells will be helpful for developing and refining the new immunological therapies for COPD.

Disturbed Th17/Treg Balance in Patients with Non-small Cell Lung Cancer.

The fine balance of T help-17 (Th17)/regulatory T(Treg) cells is crucial for maintenance of immune homeostasis. However, there is little information concerning the role played in non-small cell lung cancer (NSCLC) by Th17/Treg cells. The objective of this study was to investigate the variation of Th17 and Treg cells in the peripheral blood of patients with NSCLC. Blood samples were collected from 19 patients with NSCLC and 19 healthy donors. Samples were processed to detect CD4(+)IL-17(+) Th17 cells and CD4(+)CD25(+)Foxp3(+) Treg cells by flow cytometry, and related gene expressions were assessed by real-time quantitative polymerase chain reaction. The concentrations of interleukin (IL)-1ß, IL-6, IL-10, IL-17, IL-23, and transforming growth factor-beta (TGF-ß1) were also measured by enzyme-linked immunosorbent assay analysis (ELISA). The frequency of circulating Th17 cells and Treg cells was increased in samples derived from patients with NSCLC, accompanied by the upregulation of Foxp3 and RORγt. However, a negative correlation between Treg cells and Th17 cells was found in patients with NSCLC. Additionally, the Th17/Treg ratio and the related cytokines were also significantly higher in patients with NSCLC than in healthy controls. Furthermore, the frequency of Th17 cells was positively correlated with IL-1ß, IL-6, and IL-23 in patients with NSCLC, and the frequency of Treg cells was positively correlated with TGF-ß1 and IL-10. More importantly, the Th17/Treg ratio was positively correlated with the CEA concentrations in patients with NSCLC. Our data indicated that Th17 and Treg subset are involved in the immunopathology of NSCLC. Distinct cytokine environment might play a key role in the differentiation of the Th17 and Treg cells in NSCLC. Reconstituting an adequate balance between Th17 and Treg may be beneficial in the treatment of NSCLC.

The Treg/Th17 paradigm in lung cancer.

Pathogenic mechanisms underlying the development of lung cancer are very complex and not yet entirely clarified. T lymphocytes and their immune-regulatory cytokines play a pivotal role in controlling tumor growth and metastasis. Following activation by unique cytokines, CD4+ T helper cells differentiate into Th1, Th2, Th17, and regulatory T cells (Tregs). Traditionally, research in lung cancer immunity has focused almost exclusively on Th1/Th2 cell balance. Recently, Th17 cells and Tregs represent an intriguing issue to be addressed in lung cancer pathogenesis. Tregs play an important role in the preservation of self-tolerance and modulation of overall immune responses against tumor cells. Th17 cells directly or via other proinflammatory cytokines modulate antitumor immune responses. Notably, there is a close relation between Tregs and Th17 cells. However, the possible interaction between these subsets in lung cancer remains to be elucidated. In this setting, targeting Treg/Th17 balance for therapeutic purposes may represent a useful tool for lung cancer treatment in the future. The purpose of this review is to discuss recent findings of the role of these novel populations in lung cancer immunity and to highlight the pleiotropic effects of these subsets on the development and regulation of lung cancer.

Persistence of Th17/Tc17 cell expression upon smoking cessation in mice with cigarette smoke-induced emphysema.

Th17 and Tc17 cells may be involved in the pathogenesis of chronic obstructive pulmonary disease (COPD), a disease caused predominantly by cigarette smoking. Smoking cessation is the only intervention in the management of COPD. However, even after cessation, the airway inflammation may be present. In the current study, mice were exposed to room air or cigarette smoke for 24 weeks or 24 weeks followed by 12 weeks of cessation. Morphological changes were evaluated by mean linear intercepts (Lm) and destructive index (DI). The frequencies of CD8(+)IL-17(+)(Tc17) and CD4(+)IL-17(+)(Th17) cells, the mRNA levels of ROR gamma and IL-17, and the levels of IL-8, TNF-alpha, and IFN-gamma in lungs or bronchoalveolar lavage fluid of mice were assayed. Here we demonstrated that alveolar enlargement and destruction induced by cigarette smoke exposure were irreversible and that cigarette smokeenhanced these T-cell subsets, and related cytokines were not significantly reduced after smoking cessation. In addition, the frequencies of Th17 and Tc17 cells in lungs of smoke-exposed mice and cessation mice were positively correlated with emphysematous lesions. More important, the frequencies of Tc17 cells were much higher than Th17 cells, and there was a significantly positive correlation between Th17 and Tc17. These results suggested that Th17/Tc17 infiltration in lungs may play a critical role in sustaining lung inflammation in emphysema. Blocking the abnormally increased numbers of Tc17 and Th17 cells may be a reasonable therapeutic strategy for emphysema.

[Expression of interleukin-21 in the lungs of mice with emphysema and its effects on the differentiation of CD4+ T cell].

OBJECTIVE: To evaluate the expression of interleukin (IL)-21 in a cigarette smoke-induced mice model of emphysema and explore its effects on the differentiation of CD4(+)T cell. METHODS: Twenty male Balb/c mice were randomly divided into two groups: control group and smoke-exposed group. Morphological changes were evaluated by mean linear intercepts and alveolar destructive index. The proportion of CD4(+)IL-21R(+)T cells in lungs of mice was determined by flow cytometry. And the levels of IL-21 in lungs of mice were analyzed by enzyme-linked immunosorbent assay (ELISA). Fresh lung mononuclear cells were isolated from the smoke-exposed group and divided further into two sub-groups: blank sub-group and co-culture sub-group. Two sub-groups were cultured in medium with or without IL-21 for 24 h and 48 h. The proportions of Th1 and Th17 cells in cell culture medium were determined by flow cytometry. RESULTS: Mean linear intercepts and alveolar destructive index in the smoke-exposed group ((48.6 ± 4.8) µm and 44.9 ± 2.8) were significantly higher than the control group ((32.4 ± 4.0) µm and 28.1 ± 2.1, both P < 0.05). In lungs, the percentage of CD4(+)IL-21R(+)T cells in the smoke-exposed group (4.1% ± 1.5%) significantly increased than that in the control group (1.4% ± 0.4%) (P < 0.05). The levels of IL-21 in lung of the smoke-exposed group ((851 ± 28) ng/L) were higher than those in the control group ((415 ± 39) ng/L, P < 0.05). In lungs, the levels of IL-21 had positive correlations with mean linear intercepts and alveolar destructive index (r = 0.892 and 0.955, both P < 0.05). The percentages of Th1 and Th17 cells in cell culture medium of the co-culture sub-group for 24 h and 48 h significantly increased versus those in the blank group (all P < 0.05). CONCLUSION: IL-21 may participate in the occurrence and development of emphysema through the induced differentiation of CD4(+)T cells and the promotion of Th1 and Th17-cell responses in lungs.

Th17 cell enhances CD8 T-cell cytotoxicity via IL-21 production in emphysema mice.

Emphysema is a T-cell mediated autoimmune disease caused predominantly by cigarette smoking. Th17 cells and related cytokines may contribute to this disorder. However, the possible implication of Th17 cells in regulating inflammatory response in emphysema remains to be elucidated. In the current study, we tested the protein levels of IL-17 and IL-21 in peripheral blood and lung tissues from cigarette-smoke- (CS-) exposed mice and air-exposed mice, analyzed the frequencies of CD4(+)IL-17(+)(Th17) cells, IL-21(+)Th17 cells, and CD8(+)IL-21R(+) T cells in peripheral blood and lung tissues of mice, and their relationship with emphysematous lesions, and explored the impact of IL-21 on cytotoxic CD8(+) T cells function in vitro. It was found that the frequencies of Th17, IL-21(+)Th17, and CD8(+)IL-21R(+) T cells and the levels of IL-17 and IL-21 of CS-exposed mice were much higher than those of the air-exposed mice and correlated with emphysematous lesions. Additionally, the number of IL-21(+)Th17 cells positively correlated with the number of CD8(+)IL-21R(+) T cells. The in vitro experiments showed that IL-21 significantly augmented the secretion of perforin and granzyme B in CD8(+) T cells from CS-exposed mice. These data indirectly provide evidence that Th17 cells could be involved in the control of the local and system inflammatory response in emphysema by regulating CD8(+) cytotoxic T-cell function.

[The expression and mechanisms of interleukin-17 in CD(8)(+) T cells of mice with cigarette smoke-induced emphysema].

OBJECTIVE: To evaluate the expression of Tc17 in a cigarette smoke-induced mice model of emphysema. To explore the probable mechanisms about how Tc17 cells to elevate in lungs of mice. METHODS: Forty male Balb/c mice were randomly divided into four groups, including control group (12 weeks, C12), control group (24 weeks, C24), smoke-exposure group (12 weeks, S12) and smoke-exposure group (24 weeks, S24), 10 mice each group, Emphysema of mice was observed by HE pigmentation. Morphological changes were evaluated by mean linear intercepts (Lm) and destructive index (DI). The proportion of CD(8)(+)IL-17(+)Tc17, CD(8)(+)IL-17(+) CC chemokine receptor type 6 (CCR6)(+) and 6CCR6(+)Tc17 cells in lungs of mice was determined by flow cytometry. The mRNA expressions of retinoid-related orphan nuclear receptor (RORγt) and IL-17 were evaluated by real-time PCR. The levels of IL-1ß, IL-6, IL-23, transforming growth factor ß (TGFß) and CC chemokine ligand 20(CCL20) were tested by ELISA. Correlations among these indexes were analyzed. RESULTS: Lm and DI were significantly higher in S12 and S24 than in C12 and C24, S24 in particular (t value 4.378 - 15.188, all P < 0.05). The percentages of Tc17 in S12 and S24 [(9.28 ± 1.12)%, (13.13 ± 3.56)%] was significantly increased as compared with that in C12 and C24 [(2.40 ± 0.60)%, (2.64 ± 0.96)%], S24 in particular. The mRNA levels of RORγt and IL-17 in S12 and S24 were higher than in C12 and C24, S12 and S24 in particular. There was significant difference (all P < 0.05). The frequency of Tc17 cells had a positive correlation with Lm and DI (r value were 0.734 and 0.884 respectively, P < 0.01). The percentages of CD(8)(+)IL-17(+)CCR6(+)T cells and CCR6(+)Tc17 were significantly elevated in S12 and S24 compared to C12 and C24, S24 in particular (all P < 0.05). There was positive correlation between Tc17 cell ratio and CCL20 levels (r = 0.899, P < 0.01). The levels of IL-1ß, IL-6, IL-23 and TGFß in S12 and S24 were significantly increased as compared with that in C12 and C24. There was significant difference (all P < 0.05). Meanwhile, the frequency of Tc17 cells had a positive correlation with IL-1ß, IL-6, IL-23, and TGFß. CONCLUSIONS: An up-regulation of proportions Tc17 in lungs of cigarette smoke-induced emphysema mice were detected. The CCR6/CCL20 axis and the increased IL-1ß, IL-6, IL-23 and TGFß probably contributed to this up-regulation.

[Mechanisms and dynamics of Th17 cells in mice with cigarette smoke-induced emphysema].

OBJECTIVE: To evaluate the expression of Th17 cell in a cigarette smoke-induced mice model of emphysema and explore the probable mechanisms of its elevation. METHODS: Forty male Balb/c mice were randomly divided into 4 groups: control group for 12 weeks (C12), control group for 24 weeks (C24), smoke-exposure group for 12 weeks (S12) and smoke-exposure group for 24 weeks (S24)(n = 10 each). Morphological changes were evaluated by mean linear intercepts (Lm) and destructive index (DI). The percentages of Th17, Th1, Th17/Th1, CD4(+)IL-17(+)CCR6(+)T and CCR6(+)Th17 cells were determined by tetra-color flow cytometry while the levels of interleukin (IL)-1ß, IL-6, IL-23, transforming growth factor (TGF)-ß, interferon (IFN)-γ and CC chemokine ligand (CCL)-20 assayed by enzyme-linked immunosorbent assay (ELISA). RESULTS: The values of Lm [(39 ± 4) µm, (47 ± 7) µm] and DI [(39.1 ± 1.6), (45.2 ± 3.1)] were significantly higher in S12 and S24 than those in C12 [(33 ± 3) µm, (28.2 ± 1.6)] and C24 [(32 ± 4) µm, (28.9 ± 2.1)], particularly in C24 (all P < 0.05). The percentages of Th17 cell [(3.27 ± 1.12), (7.19 ± 2.24)], Th17/Th1 cell [(0.61 ± 0.30), (1.82 ± 0.52)] and Th1 cell [(10.02 ± 3.68), (26.21 ± 6.04)] in the lungs of S12 and S24 significantly increased than those in C12 [(1.80 ± 0.75), (0.27 ± 0.12), (3.75 ± 1.72)] and C24 [(1.99 ± 0.59), (0.28 ± 0.11), (4.16 ± 1.32)], particularly in C24 (all P < 0.01). The percentages of Th17, Th17/Th1 and Th1 cells in the lungs of S12 and S24 had a positive correlation with Lm and DI (all P < 0.01). The percentages of CD4(+)IL-17(+)CCR-6(+)T cell [(0.69 ± 0.34), (1.11 ± 0.48)] and CCR6(+)Th17 cell [(12.23 ± 2.13), (18.65 ± 1.17)] were significantly elevated in S12 and S24 compared to those in C12 [(0.22 ± 0.18), (6.55 ± 2.13)] and C24 [(0.25 ± 0.17), (7.29 ± 1.57)], particularly in C24 (all P < 0.05). Furthermore, a positive correlation between CCR6(+)Th17 cell and emphysematous lesions was also found (all P < 0.05). The levels of IL-1ß, IL-6, IL-23, TGF-ß, IFN-γ and CCL20 significantly increased in S12 and S24 as compared with those of C12 and C24 (all P < 0.05). Meanwhile, the percentage of Th17 cell had a positive correlation with IL-1ß, IL-6, IL-23, TGF-ß, IFN-γ and CCL20. CONCLUSION: There is an up-regulated expression of Th17 in lungs of cigarette smoke-induced emphysema mice. The CCR6/CCL20 axis and the elevated levels of IL-1ß, IL-6, IL-23, TGF-ß and IFN-γ may be related with the above effect.

[Effect of interleukin-17-producing CD4+ T helper lymphocytes on cigarette smoke-induced lung inflammation and emphysema in mice].

OBJECTIVE: To evaluate the expression and the role of Th17 in cigarette smoke-induced lung inflammation and emphysema in mice. METHODS: Forty male BALB/c mice were randomly divided into 4 groups, including a control group C12, a control group C24, a smoke-exposure 12 week group (S12) and a smoke-exposure 24 week group S24 (n = 10 each). Morphological changes were evaluated by mean linear intercepts and destructive index (DI). The proportion of CD(4)(+)IL-17(+)Th17, CD(4)(+)IFN-γ(+)Th1, CD(4)(+)IL-17(+)IFN-γ(+)T(Th17/Th1), CD(8)(+)IFN-γ(+)Tc1, CD(8)(+)IL-21R(+) and CD(4)(+)IL-17(+)IL-21(+) T cells in lungs of mice was determined by flow cytometry. The mRNA expressions of RORγt and IL-17 were evaluated by real-time PCR. RESULTS: Mean linear intercepts and DI were significantly higher in S12 and S24 groups [(39 ± 4) µm, (47 ± 7) µm], (39.1 ± 1.6, 45.2 ± 3.1) as compared to C12 [(32 ± 4) µm, 28.2 ± 1.6] and C24 groups [(33 ± 3) µm, 28.9 ± 2.1], all P < 0.05. The percentage of Th17 of S12 and S24 groups [(3.3 ± 1.1)%, (7.2 ± 2.2)%] was significantly increased as compared with that of C12 and C24 groups [(1.8 ± 0.8)%, (2.0 ± 0.6)%], all P < 0.05. The mRNA levels of RORγt [(25 ± 4), (35 ± 3)] and IL-17 [(26 ± 3), (36 ± 3)] in S12 and S24 groups were higher than in C12 [(10 ± 5), (13 ± 5)] and C24 groups [(11 ± 7), (8 ± 6)], all P < 0.05. The percentage of Th1, Th17/Th1 and Tc1 cells of S12 and S24 groups [(10.0 ± 3.7)%, (26.2 ± 6.0)%], [(0.61 ± 0.30)%, (1.82 ± 0.52)%], [(17.0 ± 4.5)%, (26.8 ± 8.5)%] was significantly increased as compared with that of C12 [(3.8 ± 1.7)%, (0.27 ± 0.17)%, (4.8 ± 1.9)%] and C24 groups [(4.2 ± 1.3)%, (0.28 ± 0.11)%, (5.2 ± 1.0)%], all P < 0.05. Moreover, the frequency of Th17 cells had a positive correlation with Th1, Tc1 cells and emphysematous lesions (r = 0.519 - 0.797, all P < 0.01). In addition, a positive correlation between Th17/Th1 cells and emphysematous lesions was also found (r = 0.742, 0.802, all P < 0.01). The percentage of CD(4)(+)IL-17(+)IL-21(+) T cells was significantly increased in S12 and S24 groups [(0.19 ± 0.04)%, (0.55 ± 0.24)%] compared to controls [(0.07 ± 0.03)%, (0.08 ± 0.03)%], all P < 0.05. Meanwhile, as compared with that of the controls [(1.22 ± 0.31), (1.34 ± 0.18)], the percentage of CD(8)(+)IL-21R(+) T cells was also increased in S12 and S24 groups [(2.94 ± 1.26), (4.12 ± 2.26)], but there were no differences among smoke-exposure groups (P > 0.05). The frequency of CD(4)(+)IL-17(+)IL-21(+) T cells had a positive correlation with Th1, Tc1 cells and emphysematous lesions (r = 0.694 - 0.754, all P < 0.05). And the frequency of CD(8)(+)IL-21R(+) T cells also had a positive correlation with emphysematous lesions (r = 0.516, 0.725, all P < 0.05). CONCLUSIONS: Cigarette smoke increased the expression and the activity of Th17 in mice. Th17 may play a potential (active) role in the development of lung inflammation through IL-21/IL-21R pathway.