An analysis of cytokine status in the serum and effusions of patients with tuberculous and lung cancer

The evolving landscape of IL-10, IL-22 and IL-26 in pleurisy especially in tuberculous pleurisy

Pleurisy can be categorized as primary or secondary, arising from immunological, tumorous, or microbial conditions. It often results in lung structure damage and the development of various respiratory issues. Among the different types, tuberculous pleurisy has emerged as a prominent focus for both clinical and scientific investigations. The IL-10 family, known for its anti-inflammatory properties in the human immune system, is increasingly being studied for its involvement in the pathogenesis of pleurisy. This review aims to present a detailed overview of the intricate role of IL-10 family members (specifically IL-10, IL-22, and IL-26) in human and animal pleuritic diseases or relevant animal models. These insights could serve as valuable guidance and references for further studies on pleurisy and potential therapeutic strategies.

Enhanced antitumor immune response in melanoma tumor model by anti-PD-1 small interference RNA encapsulated in nanoliposomes

Programmed cell death protein-1 (PD-1), as an immune checkpoint molecule, attenuates T-cell activity and induces T-cell exhaustion. Although siRNA has a great potential in cancer immunotherapy, its delivery to target cells is the main limitation of using siRNA. This study aimed to prepare a liposomal formulation as a siRNA carrier to silence PD-1 expression in T cells and investigate it's in vivo antitumor efficacy. The liposomal siRNA was prepared and characterized by size, zeta potential, and biodistribution. Following that, the uptake assay and mRNA silencing were evaluated in vitro at mRNA and protein levels. siRNA-PD-1 (siPD-1)-loaded liposome nanoparticles were injected into B16F0 tumor-bearing mice to evaluate tumor growth, tumor-infiltrating lymphocytes, and survival rate. Liposomal siPD-1 efficiently silenced PD-1 mRNA expression in T cells (P < 0.0001), and siPD-1-loaded liposomal nanoparticles enhanced the infiltration of T-helper 1 (Th 1) and cytotoxic T lymphocytes into the tumor tissue (P < 0.0001). Liposome-PD-1 siRNA monotherapy and PD-1 siRNA-Doxil (liposomal doxorubicin) combination therapy improved the survival significantly, compared to the control treatment (P < 0.001). Overall, these findings suggest that immunotherapy with siPD-1-loaded liposomes by enhancing T-cell-mediated antitumor immune responses could be considered as a promising strategy for the treatment of melanoma cancer.

Th17 cells and their related cytokines: vital players in progression of malignant pleural effusion

Malignant pleural effusion (MPE) is an exudative effusion caused by primary or metastatic pleural carcinosis. Th17 cells and their cytokines are critical components in various disease including MPE. In this review, we summarize current published articles regarding the multifunctional roles of Th17 cells and their related cytokines in MPE. Th17 cells are accumulated in MPE compared with paired serum via certain manners. The upregulation of Th17 cells and the interactions between Th17 cells and other immune cells, such as Th1 cells, Th9 cells, regulatory T cells and B cells, are reported to be involved in the formation and development of MPE. In addition, cytokines, which are elaborated by Th17 cells, including IL-17A, IL-17F, IL-21, IL-22, IL-26, GM-CSF, or associated with Th17 cells differentiation, including IL-1β, IL-6, IL-23, TGF-β, are linked to the pathogenesis of MPE through exerting pro- or anti-tumorigenic functions on their own as well as regulating the generation and differentiation of Th17 cells in MPE. Based on these findings, we proposed that Th17 cells and their cytokines might be diagnostic or prognostic tools and potential therapeutic targets for MPE.

A meta-analysis of Th1 and Th2 cytokine profiles differentiating tuberculous from malignant pleural effusion

To clarify the predominance of Th1 or Th2 immune responses in malignant and tuberculous pleural effusion (MPE and TPE, respectively), we performed a meta-analysis of previously published results of the levels of Th1/Th2 cytokines associated with these two types of pleural effusion to evaluate the use of Th1/Th2 cytokine profiles in distinguishing TPE from MPE. We searched the PubMed and EMBASE databases for studies indexed from 2000 to March 2021. We included studies that (a) diagnosed TPE and MPE based on culture or pleural tissue biopsy and that (b) compared levels of Th1/Th2 cytokines between TPE and MPE. Pooled data based on a random-effects model or fixed-effects model and standardized mean differences (SMDs) across studies were used to compare TPE and MPE. We also performed Egger’s test to assess publication bias. Of 917 identified studies, a total of 42 studies were selected for the meta-analysis. Compared with MPE subjects, TPE subjects had a significantly higher level of TNF-α [2.22, (1.60–2.84)], an elevated level of IFN-γ [3.30, (2.57–4.40)] in pleural effusion, a situation where the Th1 immune response dominated. Conversely, the levels of interleukin-4 (IL-4) and IL-10 (Th2 cytokines) were higher in the MPE subjects than in the TPE subjects, showing statistically nonsignificant tiny effects [−0.15, (−0.94 to 0.63) and −0.04, (−0.21 to 0.12), respectively]. We confirmed that TPE, a situation in which the Th1 cytokines are predominant. The slight preponderance of Th2 cytokines in MPE, which is not convincing enough to prove.

Heat-killed Mycobacterium tuberculosis prime-boost vaccination induces myeloid-derived suppressor cells with spleen dendritic cell-killing capability

Tuberculosis patients and mice infected with live Mycobacterium tuberculosis (Mtb) accumulate high numbers of myeloid-derived suppressor cells (MDSCs). Here, we hypothesized that also dead Mtb vaccines may induce MDSCs that could impair the efficacy of vaccination. We found that repeated injections of Mtb vaccines (heat-killed Mtb in Incomplete Freund's Adjuvant, like Montanide) but not single or control vaccines without Mtb strongly expanded CD11b+ myeloid cells in the spleen, that suppressed T cell proliferation and killing ex vivo. Dead Mtb vaccination induced the generation of CD11b+ Ly-6Chigh CD115+ iNOS/Nos2+ monocytic MDSCs (M-MDSCs) upon application of inflammatory or microbial activation signals. In vivo these M-MDSCs positioned strategically in the spleen by infiltrating the splenic bridging channels and white pulp areas. Notably, within 6 to 24 hours in a Nos2-dependent fashion they produced NO to rapidly kill conventional and plasmacytoid dendritic cells (cDCs, pDCs) while, surprisingly, sparing T cells in vivo. Thus, we demonstrate that Mtb vaccine induced M-MDSCs to not directly suppress T cell in vivo but, instead, M-MDSCs directly target DC subpopulations thereby indirectly suppressing effector T cell responses. Collectively, we demonstrate that Mtb booster vaccines induce M-MDSCs in the spleen that can be activated to kill DCs cautioning to thoroughly investigate MDSC formation in individuals after Mtb vaccination in clinical trials.

IL-10 promotes malignant pleural effusion in mice by regulating TH 1- and TH 17-cell differentiation and migration

The role of IL-10 in malignant pleural effusion (MPE) remains unknown. By using murine MPE models, we observed that an increase in pleural IL-10 was a significant predictor of increased risk of death. We noted that T_H 1- and T_H 17-cell content in MPE was higher in IL-10^-/- mice than in WT mice, and IL-10 deficiency promoted differentiation into T_H 1 but not into T_H 17 cells. A higher fraction of T_H 1 and T_H 17 cells in the MPE of IL-10^-/- mice expressed CXCR3 compared with WT mice. We also demonstrated that Lewis lung cancer and colon adenocarcinoma cells secreted large amounts of CXCL10, a ligand of CXCR3, which induced the migration of T_H 1 and T_H 17 cells into the MPE, and IFN-γ could promote this signaling cascade. Furthermore, intrapleural injection of mice with CXCL10-deficient tumor cells led to decreased T_H 1- and T_H 17-cell content in MPE, increased MPE volume, and reduced survival of MPE-bearing mice. Taken together, we demonstrated that IL-10 deficiency promoted T-cell differentiation into T_H 1 cells and upregulated the CXCR3-CXCL10 signaling pathway that recruits T_H 1 and T_H 17 cells into MPE, ultimately resulting in decreased MPE formation and longer survival time of mice-bearing MPE.

Diagnostic and Prognostic Significance of Inflammatory Markers in Lung Cancer-Associated Pleural Effusions

Besides massive expression in inflammatory pleural effusions, inflammatory markers are also present in cancer-induced pleural effusions. Recent advances in cancer biology point to a role of inflammatory signaling in cancer and encourage reconsidering the diagnostic and prognostic value of inflammatory markers. Here an attempt was made to relate protein levels of inflammatory markers to underlying malignant processes in the pleural space.

Pleural effusions from lung cancer patients (n=116) were subjected to a multifactorial analysis covering 13 inflammatory markers. The composition of tumor-associated effusions was compared with that of parainflammatory pleural effusions (n=30), transudates (n=18), and serum values, and evaluated in relation to cancer origin, histology, cytology, pleural involvement, treatment history, and survival time.

Inflammatory markers were significantly expressed in pleural effusions of paraneoplastic origin when compared to transudates and most serum levels. Values in pleura-invading and metastatic tumor-associated effusions were typically higher than those of other tumors. Many markers correlated negatively with survival, most prominently IL-8 (r=–0.36, p=0.001) and VEGF (r=–0.35, p=0.001).

It appears that most inflammatory markers are highly expressed in tumor-associated pleural effusions, reflecting to some extent tumor origin and localization. Despite the lower efficacy of inflammatory markers in the differentiation between exudative pleural effusions, some inflammatory markers may represent potential prognostic markers of malignant processes in the pleural space.

Vascular endothelial growth factor and protein level in pleural effusion for differentiating malignant from benign pleural effusion

Pleural effusion is associated with multiple benign and malignant conditions. Currently no biomarkers differentiate malignant pleural effusion (MPE) and benign pleural effusion (BPE) sensitively and specifically. The present study identified a novel combination of biomarkers in pleural effusion for differentiating MPE from BPE by enrolling 75 patients, 34 with BPE and 41 with MPE. The levels of lactate dehydrogenase, glucose, protein, and total cell, neutrophil, monocyte and lymphocyte counts in the pleural effusion were measured. The concentrations of interleukin (IL)-1β, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, tumor necrosis factor-α, interferon γ, transforming growth factor-β1, colony stimulating factor 2, monocyte chemoattractant protein-1 and vascular endothelial growth factor (VEGF) were detected using cytometric bead arrays. Protein and VEGF levels differed significantly between patients with BPE and those with MPE. The optimal cutoff value of VEGF and protein was 214 pg/ml and 3.35 g/dl respectively, according to the receiver operating characteristic curve. A combination of VEGF >214 pg/ml and protein >3.35 g/dl in pleural effusion presented a sensitivity of 92.6% and an accuracy of 78.6% for MPE, but was not associated with a decreased survival rate. These results suggested that this novel combination strategy may provide useful biomarkers for predicting MPE and facilitating early diagnosis.

Expression of Th1- Th2- and Th17-associated cytokines in laryngeal carcinoma

T-helper (Th) 0 cell differentiation into Th1 or Th2 cells is dependent on a number of transcription factors that act at specific time points to regulate gene expression. Th17 cells, a subset of interleukin (IL)-17-producing T cells distinct from Th1 or Th2 cells, are considered to exhibit a critical function in inflammation and autoimmune diseases, as well as cancer development. In the present study, the expression of Th1-, Th2- and Th17-associated cytokines in laryngeal cancer and pericarcinoma tissues obtained from 57 laryngeal carcinoma patients was investigated. The association between Th1, Th2 and Th17 infiltration and tumor development was also evaluated. Reverse transcription-polymerase chain reaction and western blotting results revealed that the mRNA and protein expression of Th2 cytokines was lower, while the expression of Th1 and Th17 cytokines was higher in tumor tissues than in pericarcinoma tissues. Furthermore, the early stage cancer patients exhibited a higher level of interferon-γ, IL-2 and IL-17 mRNA expression than those at advanced stages. Cancer tissues exhibited higher Th17 cytokine expression than pericarcinoma tissues. By contrast, Th1 cytokine expression was increased in pericarcinoma tissues compared with cancer tissues. These results indicate that high expression of Th1- and Th17-associated cytokines in laryngeal carcinoma may contribute to suppression of cancer development and a relatively good prognosis.

Expression Profiles of Cytokine mRNAs in the Pleural Fluid Reveal Differences Among Tuberculosis, Malignancies, and Pneumonia-Exudative Pleural Effusions

INTRODUCTION

Tuberculosis (TB) and malignant diseases are the most common causes of lymphocytic pleural effusion in adults. Serum and pleural fluid cytokine levels have been analyzed to help in the differential diagnosis, but with limited results.

PURPOSE

This study investigates transcription levels of selected cytokine genes in pleural effusion of patients under investigation for TB.

METHODS

This was a prospective study that included adult patients under investigation for pleural effusion in Brazil. The expression of 19 cytokine genes was analyzed by RT-qPCR.

RESULTS

The majority of cytokine-related genes expressed in pleural fluid of TB patients were similar in non-TB patients, except for RORA and RORC genes, which showed a statistically higher level in TB. All cytokines in the Th17 pattern were induced in TB patients' pleural fluid. Patients with malignant pleural effusion expressed higher levels of IFN-α1, IFN-β1, TNF-α, IL-4 and IL-6, and suppression of TGFβ-1.

CONCLUSION

There is still a lot to understand about the cytokine roles in the pro- and anti-inflammatory environment of exudative pleural effusions. The data presented here showed an increased expression of Th17 pattern cytokines genes in TB patients that could be used as markers to differentiate tuberculous pleuritis from other common causes of exudative pleural effusion.

High IL-35 pleural expression in patients with tuberculous pleural effusion

Background

IL-35 is a novel anti-inflammatory and immunosuppressive cytokine primarily produced by Treg cells, and is involved in inflammatory diseases and autoimmune diseases. However, its roles in tuberculous pleural effusion (TPE) remain unknown. We aimed to investigate the potential involvement of IL-35 in TPE.

Material/Methods

Thirty TPE patients and 20 lung cancer patients with malignant pleural effusion (MPE) were recruited. Samples of pleural effusion (100 mL) were collected after traditional pleurocentesis. Blood was sampled from TPE patients. Mononuclear cells were isolated by Ficoll-Hypaque gradient. Proportions of Th1, Th17, and IL-35-producing cells were analyzed by flow cytometry. IL-35 was assessed by real-time RT-PCR, ELISA, and immunofluorescence. An ELISPOT assay was used to assess the effect of IL-35 on pleural effusion mononuclear cells (PEMCs).

Results

Proportions of IL-35-producing cells were higher in TPE compared with MPE (49.4±6.0 vs. 15.8±5.4%, P<0.001) and blood from TPE patients (49.4±6.0% vs. 16.6±3.1, P<0.001). IL-35, IL-17 and IFN-γ were elevated in TPE compared with MPE (all P<0.01). ELISPOT assay showed that IL-35 reduced the proportion of IFN-γ-producing CD4⁺ T cells in TPE. IL-35 mRNA expression was higher in TPE compared with MPE (P<0.001). Immunofluorescence showed that IL-35-positive cells were present in pleural tissues from TPE patients.

Conclusions

Results suggest that there is an imbalance in IL-35 metabolism in TPE. However, further studies are required to assess the exact relationship with the immune system response to tuberculosis. IL-35 might play a role in TPE and might be targeted as a treatment for TPE.

Diagnostic utility of serum and pleural levels of adenosine deaminase 1-2, and interferon-γ in the diagnosis of pleural tuberculosis

Background

To evaluate and compare the diagnostic efficiency of serum (s) and pleural (p) levels of adenosine deaminase (ADA)-1, ADA-2, total ADA, and interferon-gamma (IFN-γ) for the differential diagnosis of pleural tuberculosis (TB).

Methods

Clinical and analytic data of 93 consecutive patients with pleural effusions from May 2012 to February 2013 were prospectively evaluated. The study population included 43 pleural TB, 23 malignancies, and 27 other exudates. The median and interquartile range of ADA-1, ADA-2, total ADA, and IFN-γ were evaluated according to their underlying diseases.

Results

There were no significant differences in sADA-1 and sIFN-γ values among each group. pADA-1, pADA-2, total pADA, and pIFN-γ levels were significantly higher in patients with pleural TB than in other patients (p < 0.0001). As for pleural TB receiving operating characteristic (ROC) curves identified the following results. The best cut-off value for pADA-2 was 20.37 U/L and it yielded a sensitivity and specificity of 95.35% and 86%, respectively. Taking a cut-off value of 40.68 U/L for total pADA, the sensitivity and the specificity were found to be 88.37% and 88%, respectively. ROC curve identified 110 U/L as the best cut-off value for pμg/ml, while the sensitivity and the specificity were 74.42% and 68%, respectively. Finally, the best cut-off value for pADA-1 was 16.8 U/L and yielded a sensitivity and specificity of 69.77% and 68%, respectively.

Conclusions

To distinguish pleural TB, pleural levels of ADA-2 have the highest sensitivity among the different diagnostic parameters and may find a place as routine investigation for early detection of TB in the future.

Diagnostic value of ex vivo pleural fluid interferon-gamma versus adapted whole-blood quantiferon-TB gold in tube assays in tuberculous pleural effusion

BACKGROUND:

Noninvasive diagnosis of pleural tuberculosis (TB) remains a challenge due to the paucibacillary nature of the disease. As Mycobacterium tuberculosis (MTB)-specific T cells are recruited into pleural space in TB effusion; their indirect detection may provide useful clinical information.

OBJECTIVES:

Evaluation of pleural fluid interferon (INF)-γ levels vs Quantiferon–TB Gold In tube assay (QFT- IT) in blood and its adapted variants, using pleural fluid or isolated pleural fluid cells in the diagnosis of pleural TB.

METHODS:

Thirty-eight patients with pleural effusion of unknown etiology presented at Assiut University Hospital, Egypt, were recruited. Blood and pleural fluid were collected at presentation for INF-γ assays. Ex vivo pleural fluid INF-γ levels, QFT-IT in blood and its adapted variants were compared with final diagnosis as confirmed by other tools including blind and/or thoracoscopic pleural biopsy.

RESULTS:

The final clinical diagnosis was TB in 20 (53%), malignancy in 10 (26%), and effusion due to other causes in eight patients (21%). Ex vivo pleural fluid INF-γ levels accurately identified TB in all patients and were superior to the QFT-IT assays using blood or pleural fluid (70 and 78% sensitivity, with 60 and 83% specificity, respectively). QFT-IT assay applied to isolated pleural fluid cells had 100% sensitivity and 72% specificity. The optimal cut-off obtained with ROC analysis was 0.73 for TB Gold assay in blood assay, 0.82 IU/ml for the cultured pleural fluid assay, and 0.94 for isolated pleural cells assay.

CONCLUSION:

The ex vivo pleural fluid INF-γ level is an accurate marker for the diagnosis of pleural TB. QFT- IT assay in peripheral blood or its adapted versions of the assay using pleural fluid and/or washed pleural fluid cells had no diagnostic advantage over pleural fluid INF-γ in the diagnosis of pleural TB.

Interleukin-10-819C>T polymorphism contributed to cancer risk: evidence from 29 studies

Cytokines are important modulators in the interactions between the host immune system and malignant tumor. Of these, Interleukin-10 (IL-10) is an important immunoregulatory cytokine mainly produced by macrophages and T lymphocytes. To date, a number of studies investigated the role of the IL-10-819C>T polymorphism in the aetiology of cancers of various organs. However, the results of these studies remain inconclusive. So, we carried out a meta-analysis on all eligible case-control studies to estimate the overall cancer risk of IL-10-819C>T polymorphism as well as to quantify the between-study heterogeneity and potential bias. This meta-analysis, including 8157 cases and 10473 controls from 29 published case-control studies, explored the association between a potentially functional polymorphism, -819C>T within the IL-10 promoter region and cancer risk. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. The results provided evidence that the IL-10-819C>T polymorphism was associated with a significant decrease in overall cancer risk. In the stratified analyses, the risk remained for studies of "other cancer", smoking-related cancer, Asian populations and hospital-based studies. This meta-analysis identified an evidence of the association between the IL-10-819C>T and cancer risk, especially in "other cancer", smoking-related cancers, Asians and hospital-based studies. Further large case-control studies, especially studies in African population were needed to validate our results.

Interleukin-10 gene promoter polymorphisms and their protein production in pleural fluid in patients with tuberculosis

Associations of interleukin-10 (IL-10) gene promoter polymorphisms and pleural tuberculosis risk remain unclear. The objective of this study was to determine IL-10 gene promoter polymorphisms at -1082, -819 and -592 sites and their protein production in pleural fluid (PF) in patients with and without pleural tuberculosis. IL-10 gene promoter polymorphisms at the -1082, -819 and -592 sites were genotyped using a SNaPshot assay. Protein levels of IL-10 in PF were measured using an enzyme-linked immunosorbent assay. There were no significant differences in the genotype and allele frequencies of IL-10 gene promoter polymorphisms at position -1082 between the pleural tuberculosis and the control groups. However, the frequency of -819 T or -592 A alleles was significantly more common in patients with pleural tuberculosis than controls. The protein levels of IL-10 in PF were statistically higher in the pleural tuberculosis group than in the control group. Moreover, the polymorphisms at the -1082, -819 and -592 sites were associated with protein levels of IL-10 in PF in the pleural tuberculosis group, while in the control group, only the polymorphism at position -1082 correlated with the protein levels. These findings support the association between IL-10 promoter polymorphisms at -819 and -592 sites and their protein production with pleural tuberculosis risk.

Serum concentrations of cytokines and lung cancer survival in African Americans and Caucasians

Accumulating evidence suggests a role for inflammation in the development and progression of cancer. Our group recently identified a cytokine gene signature in lung tissue associated with lung cancer prognosis. Therefore, we hypothesized that concentrations of circulating cytokines in serum may be associated with lung cancer survival. Ten serum cytokines, namely, interleukin (IL)-1beta, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, granulocyte macrophage colony-stimulating factor, interferon (IFN)-gamma, and tumor necrosis factor-alpha, were assessed in 353 non-small cell lung cancer cases from a case-control study of lung cancer in the greater Baltimore, Maryland area. Cytokines were measured using an ultrasensitive electrochemiluminescence immunoassay. IL-6 serum concentrations (>or=4.0 pg/mL) were associated with significantly poorer survival in both African Americans [hazard ratio (HR), 2.71; 95% confidence interval (CI), 1.26-5.80] and Caucasians (HR, 1.71; 95% CI, 1.22-2.40). IL-10 (HR, 2.62; 95% CI, 1.33-5.15) and IL-12 (HR, 1.98; 95% CI, 1.14-3.44) were associated with lung cancer survival only in African Americans. Some evidence for an association of tumor necrosis factor-alpha levels with survival in Caucasians was observed, although these results were not significant. These hypothesis-generating findings indicate that selected serum cytokine concentrations are associated with lung cancer survival, and indicate that further research is warranted to better understand the mechanistic underpinnings of these associations.

Cytokine levels in pleural effusions of patients under intensive care

BACKGROUND

Pleural effusions develop for various reasons in patients admitted to intensive care units (ICUs). To understand why this occurs is important, yet cytokine levels in pleural effusions have rarely been measured from a cardiovascular viewpoint.

OBJECTIVE

To understand the characteristics of pleural cytokines in patients admitted to the ICU.

METHODS

The subjects were 43 patients with pleural effusion who were admitted to the ICU from June 2001 through March 2006. We divided the patients into transudate (n=23) and exudate (n=20) groups. We measured levels of interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-alpha in pleural effusions and peripheral blood and evaluated their relationships with body temperature, C-reactive protein (CRP) level, and the peripheral white blood cell (WBC) count.

RESULTS

Levels of pleural IL-6 were significantly higher and levels of TNF-alpha tended to be higher in pleural effusions from the exudate than in those from the transudate group (3,350+/-3,627 vs. 1,677+/-1,086 pg/m and 6.6+/-3.4 vs. 4.8+/-2.6 pg/mL, respectively). However, in both groups levels of IL-10 in pleural effusions were similar to those in serum and levels of IL-6 were significantly higher in pleural effusion than in serum. Serum IL-6 levels correlated with inflammatory markers (CRP and body temperature), whereas cytokines in pleural effusion did not correlate with any of these markers (body temperature, CRP, and WBC).

CONCLUSION

Pleural levels of IL-6 were significantly higher in the exudate group than in the transudate group but did not correlate with serum levels of IL-6 or with systemic inflammatory markers. These findings suggest that pleural IL-6 levels correlate with local lung or pleural inflammation in patients admitted to the ICU.

IFN-gamma impairs release of IL-8 by IL-1beta-stimulated A549 lung carcinoma cells

BACKGROUND

Production of interferon (IFN)-gamma is key to efficient anti-tumor immunity. The present study was set out to investigate effects of IFNgamma on the release of the potent pro-angiogenic mediator IL-8 by human A549 lung carcinoma cells.

METHODS

A549 cells were cultured and stimulated with interleukin (IL)-1beta alone or in combination with IFNgamma. IL-8 production by these cells was analyzed with enzyme linked immuno sorbent assay (ELISA). mRNA-expression was analyzed by real-time PCR and RNase protection assay (RPA), respectively. Expression of inhibitor-kappa Balpha, cellular IL-8, and cyclooxygenase-2 was analyzed by Western blot analysis.

RESULTS

Here we demonstrate that IFNgamma efficiently reduced IL-8 secretion under the influence of IL-1beta. Surprisingly, real-time PCR analysis and RPA revealed that the inhibitory effect of IFNgamma on IL-8 was not associated with significant changes in mRNA levels. These observations concurred with lack of a modulatory activity of IFNgamma on IL-1beta-induced NF-kappaB activation as assessed by cellular IkappaB levels. Moreover, analysis of intracellular IL-8 suggests that IFNgamma modulated IL-8 secretion by action on the posttranslational level. In contrast to IL-8, IL-1beta-induced cyclooxygenase-2 expression and release of IL-6 were not affected by IFNgamma indicating that modulation of IL-1beta action by this cytokine displays specificity.

CONCLUSION

Data presented herein agree with an angiostatic role of IFNgamma as seen in rodent models of solid tumors and suggest that increasing T helper type 1 (Th1)-like functions in lung cancer patients e.g. by local delivery of IFNgamma may mediate therapeutic benefit via mechanisms that potentially include modulation of pro-angiogenic IL-8.

Differential cytokine levels and immunoreactivities against Mycobacterium tuberculosis antigens between tuberculous and malignant effusions

Much effort has been devoted to the identification of immunologically important factors in tuberculous pleurisy (TBP) and malignant pleurisy (MP) to improve the differential diagnosis of the two major causes of lymphocyte-dominant pleurisy. This study evaluated the immunoreactivity and potential diagnostic utility of both host (cytokines and chemokines) and pathogen (mycobacterial proteins) factors in pleural effusions. Effusion samples were collected from 41 patients with MP caused by lung cancer and from 81 patients with TBP. The concentrations of nine cytokines and chemokines (interleukin (IL)-12 p40, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, IL-6, IL-10, CXCL8/IL-8, CXCL10/IP-10, CCL3/MIP-1alpha, and CCL4/MIP-1beta) and antibody responses (IgG, IgM, and IgA) against five Mycobacterium tuberculosis antigens (early secreted antigenic target (ESAT)-6, 30-kDa, MTB12, 38-kDa, and a heparin-binding hemagglutinin (HBHA)) were determined in pleural fluids using enzyme-linked immunosorbent assays (ELISA). In the logistic regression, IFN-gamma (odds ratio, 7.178; 95% confidence interval (CI), 2.258-22.817; p=0.001), IL-12 p40 (odds ratio, 11.037; 95% CI, 3.38-36.037; p<0.001), and IL-6 (odds ratio, 3.295; 95% CI, 1.147-9.463; p=0.027) were found to be statistically significant cytokines predicting tuberculous from malignant effusions. Although IgG responses to all of the M. tuberculosis antigens tested were significantly higher in effusions from TBP (p<0.001) compared with those from MP, the logistic regression showed IgG levels for ESAT-6 and MTB12 to be statistically significant for differentiation of TBP from MP. HBHA showed the highest sensitivity of IgM antibody responses in TBP in comparison with other antigens. These data indicate that selected mycobacterial antigens (ESAT-6 and MTB12) and cytokine markers (IFN-gamma, IL-12p40, and IL-6) provide useful information for differentiating tuberculous and malignant effusions in clinical practice.

Macrophage-derived chemokine in malignant and tuberculous pleural effusions

BACKGROUND AND OBJECTIVES

Macrophage-derived chemokine (MDC/CCL22) is recognized as a T-helper (Th) 2-type chemokine. Both malignant and tuberculous pleural effusions are typically lymphocytic pleural effusions. Tuberculous pleural effusions have a more polarized Th1 reaction than malignant effusions, which are predominantly Th2 in nature. The aim of this study was to compare the levels of MDC in malignant pleural effusions with those in tuberculous pleural effusions to help delineate the role of MDC in Th2 versus Th1 effusions.

METHODS

Forty-three patients with pleural effusions (32 malignant, 11 tuberculous) were studied. The concentration of MDC in the pleural effusion was measured by ELISA.

RESULTS

The median concentration of MDC was lower in malignant pleural effusions than in tuberculous pleural effusions (P < 0.005).

CONCLUSIONS

MDC has been reported to both promote and suppress antitumour immunity. The low concentration of MDC in malignant effusions is likely to minimise its antitumour activity but the precise role of MDC in malignant and tuberculous effusions needs to be investigated further.

Diagnostic Value of Interferon-γ in Tuberculous Pleurisy

BACKGROUND

Conventional tests are not always helpful in making a diagnosis of tuberculous pleurisy. Many studies have investigated the usefulness of interferon (IFN)-gamma measurements in pleural fluid for the early diagnosis of tuberculous pleurisy. We conducted a metaanalysis to determine the accuracy of IFN-gamma measurements in the diagnosis of tuberculous pleurisy.

METHODS

After a systematic review of English-language studies, sensitivity, specificity, and other measures of accuracy of IFN-gamma concentrations in the diagnosis of pleural effusion were pooled using random-effects models. Summary receiver operating characteristic curves were used to summarize overall test performance.

RESULTS

Twenty-two studies met our inclusion criteria. The summary estimates for IFN-gamma in the diagnosis of tuberculous pleurisy in the studies included were as follows: sensitivity, 0.89 (95% confidence interval [CI], 0.87 to 0.91); specificity, 0.97 (95% CI, 0.96 to 0.98); positive likelihood ratio, 23.45 (95% CI, 17.31 to 31.78); negative likelihood ratio, 0.11 (95% CI, 0.07 to 0.16); and diagnostic odds ratio, 272.7 (95% CI, 147.5 to 504.2).

CONCLUSIONS

IFN-gamma determination is a sensitive and specific test for the diagnosis of tuberculous pleurisy. The measurement of IFN-gamma levels in pleural effusions is thus likely to be a useful tool for diagnosing tuberculous pleurisy. The results of IFN-gamma assays should be interpreted in parallel with clinical findings and the results of conventional tests.

Lung carcinomas decrease the number of monocytes/macrophages (CD14+ cells) that produce TNF-alpha

The role that inflammation plays in cancer is puzzling. In peripheral blood, TNF-alpha-producing monocytes (CD14+ cells) were compared among patients with lung cancer, patients with tuberculosis and healthy donors; also, in pleural effusion TNF-alpha-producing CD14+ cells were compared between tuberculous patients and lung cancer patients. To analyze the level of the cellular alteration in TNF-alpha production, an experimental model was set up. TNF-alpha-producing CD14+ cells in peripheral blood from lung cancer patients were significantly lower than those from healthy donors. In pleural effusion, TNF-alpha-producing CD14+ cells were significantly lower in lung cancer patients than in tuberculous patients. Based on the results obtained from an experimental model, we suggest that this phenomenon was attributed to a reduced expression of TNF-alpha transcript. These findings provide evidence that lung carcinomas reduce TNF-alpha production by macrophages, possibly by inducing in these cells an M2 phenotype, which favor tumor progression.

T-helper type 1/T-helper type 2 balance in malignant pleural effusions compared to tuberculous pleural effusions

STUDY OBJECTIVES

Malignant and tuberculous pleurisies are two major causes of lymphocyte-dominant pleurisy. Several studies have already reported that tuberculous pleurisy is a T-helper type 1(Th1)-dominant disease. In this study, we sought to examine the Th1/T-helper type 2 (Th2) balance, especially focusing on the polarizing status of T-cells to Th1/Th2 in malignant pleural effusions by measuring cytokines in pleural effusions and by evaluating the polarizing status of T-cells on the point of stimulation with interleukin (IL)-12 and/or IL-18. Furthermore, we evaluated inhibitors of interferon (IFN)-gamma production in effusions to rule out the possibility of direct inhibition of T-cell polarization.

PATIENTS

Effusion samples were collected from 19 patients with malignant pleurisy caused by lung cancer and from 7 patients with tuberculous pleurisy.

MEASUREMENTS

Concentrations of pleural fluid IFN-gamma, IL-12, and IL-4 were measured. IFN-gamma production of T-cells enriched from malignant pleural effusions in the presence of IL-12 and/or IL-18 was also examined. We further compared the inhibitory activity of malignant pleural effusions against IFN-gamma production and analyzed the expression of T-cell immunoglobulin mucin, mucin domain (Tim-3), a Th1-specific molecule in pleural fluid T-cells.

RESULTS

Although malignant pleural effusions showed low levels of Th1 and Th2 cytokines and ratios of IFN-gamma and IL-12 to IL-4 were low, isolated T-cells produced a significant level of IFN-gamma in the presence of IL-12 and IL-18. Soluble factors were not found to inhibit IFN-gamma production in malignant pleural effusions. In tuberculous pleural effusion, ratios of IFN-gamma and IL-12 to IL-4 were significantly higher, and T-cells showed the expression of Tim-3 messenger RNA.

CONCLUSIONS

We confirmed that T-cells in the malignant pleural effusions are mainly naïve or not definitely polarized to Th1. Moreover, malignant tumor does not actively distort the cytokine condition through production of soluble inhibitors within effusions. The present study indicates that antitumor immunity may be enhanced by restored IFN-gamma activity through combination of IL-12 and IL-18, and that it will lead to new therapies for malignant effusion.

Immunosuppressive mechanisms in the microenvironment of malignant pleural effusions

Malignant effusions in serous cavities constitute a unique milieu for direct contact of tumor cells with host lymphoid cells in a fluid phase. The aim of this study was to depict agents responsible for suppression of lymphoid cells with putative anti-tumor potential. Pleural effusions drawn from 44 (18 non-malignant and 26 malignant) patients were tested for selected cytokines--interleukin-10 (IL-10), transforming growth factor beta (TGF-beta1) and soluble Fas ligand (sFasL) and nuclear membrane proteins (NMPs) content by ELISA. TCR-zeta expression of T cells and TUNEL reaction for apoptosis were evaluated by three color flow cytometry. Both cytokine concentrations were found to be significantly elevated in malignant pleural effusions (MPE) as compared to non-malignant ones. It was also true for sFasL content. Moreover, NMPs corresponding to decoy cell fragments, were also heightened in MPE. Concentrations of NMPs correlated with the percent of apoptotic (TUNEL+) T CD3+ lymphocytes and inversely correlated with the percent of T cells. The low expression of TCR-zeta chain on T cells corresponded to high concentration of sFasL in MPE. In conclusion, the above data suggest that out of three suppression agents tested, only sFasL appears to show correlation with the downregulation of T cells in MPE.

Tumor microenvironment: What can effusions teach us?

Malignant effusions, which are composed of malignant pleural and peritoneal fluid, are an unusual manifestation of cancer and frequently portend a poor prognosis. Neoplastic cells that disseminate into cavities containing effusions are highly metastatic and possess a strong autonomous proliferative drive while concurrently being stimulatory of exudative effusions. Most effusions will respond to transient therapeutic intervention, including the obliteration of potential space via pleurodesis. Cure, however, is rare, thus making effusions a biologically, biochemically, and clinically important topic of study. The local microenvironment that supports malignant growth, invasion, and dissemination of the solid primary tumor into the vasculature is composed of activated stroma that includes scaffolding consisting of materials that promote the tumor function, and vascular structures to provide conduits for travel and nutrient delivery. Less is understood about the tumor-cell microenvironment in malignant effusions. The fluid nature of such a microenvironment when compared with the solid primary tumor may have significant implications for disease dissemination and progression. Dissecting the signaling activity and components of such microenvironments will improve our understanding and ultimately our ability to provide better patient care.

Characterization of effusion-infiltrating T cells: benign versus malignant effusions

PURPOSE

While naïve T cells circulate between peripheral blood and lymph nodes, memory effector T cells acquire certain surface molecules that enable them to travel to peripheral tissues and exert their effector function. We analyzed whether deficient numbers of effector-type T cells within the malignant effusion might contribute to tumor escape from immunosurveillance.

EXPERIMENTAL DESIGN

We analyzed the expression of a broad range of adhesion molecules and chemokine receptors (CD62L, CD56, CCR4, CCR5, CCR7, CXCR3, CLA, and integrin alpha 4 beta 7) on tumor-associated lymphocytes in effusions and peripheral blood lymphocytes of patients with malignant ascites (n = 11) or malignant pleural effusion (n = 16). A tumor-associated lymphocyte:peripheral blood lymphocyte ratio was calculated as an indicator for homing of lymphocytes into the effusions and was compared with patients with nonmalignant ascites (n = 17).

RESULTS

Patients with malignancies show an increased enrichment of T cells expressing the phenotype of "naïve" (CD62L+ and CD45RA+CCR7+), "central memory" (CD45RA-CCR7+), and type 2-polarized (CCR4+) T cells within their effusions. In contrast, enrichment of "effector"-type (CD45RA-CCR7- or CD45RA+CCR7-) and presumably type 1-polarized T cells (CCR5+) at the tumor site is deficient. The same is true for natural killer cells and potentially cytotoxic CD56+ T cells.

CONCLUSIONS

Here we show for the first time that patients with malignant effusions show a deficient enrichment of T cells expressing the phenotype of type-1-polarized effector T cells at the tumor site. This mechanism is likely to contribute to the escape of tumor cells from immunosurveillance.

Assay of pleural fluid interleukin-6, tumour necrosis factor-alpha and interferon-gamma in the diagnosis and outcome correlation of tuberculous effusion

OBJECTIVE

To assess the usefulness of interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in the diagnosis and prediction of outcome of pleural tuberculosis.

PATIENTS AND METHODS

Pleural fluid from 32 TB and 34 non-TB patients was sent for assay of IL-6, TNF-alpha and IFN-gamma. Clinical parameters at presentation and residual pleural scarring at completion of treatment were assessed for pleural TB cases.

RESULTS

The pleural fluid Levels of IL-6, TNF-alpha and IFN-gamma in TB patients were significantly higher than those with non-TB effusions (P values of <0.001, 0.018 and <0.001, respectively by independent t-test). Utility of these cytokines for diagnosis of pleural TB was evaluated using receiver operating characteristic (ROC) curve analysis. The cut-off values for IL-6, TNF-alpha and IFN-gamma determined in this analysis were 4000, 4 and 60 pg/ml respectively, and their sensitivity and specificity were 90.6% and 76.5%, 90.6% and 79.4%, 100% and 100%, respectively. The pretreatment pleural fluid IL-6 levels had a positive correlation with the number of febrile days after treatment (Pearson correlation test: r=0.60, P=0.009). A negative correlation was found between the percentage reduction in pleural fluid cytokines after 2 weeks treatment and the extent of residual pleural scarring (IL-6: r=-0.62, P=0.041; TNF-alpha: r=-0.65, P=0.030; IFN-gamma: r=0.83, P=0.002).

CONCLUSION

Pleural fluid IL-6, TNF-alpha and IFN-gamma assays are useful in the diagnosis of pleural TB. The initial IL-6 level correlates with the number of febrile days. The percentage change of cytokines after 2 weeks of treatment also helps to predict residual pleural scarring.

The Potential Contributions of Chronic Inflammation to Lung Carcinogenesis

A number of lines of evidence suggests that chronic inflammation contributes to the process of carcinogenesis. In this article, this theme is explored with particular emphasis on the involvement of inflammation in the development of lung cancer. A number of molecular pathways activated in chronic inflammation may contribute to lung carcinogenesis. The challenge is to conceptualize a cohesive picture of this complex biology that allows for effective pharmaceutical intervention. Initial therapeutic efforts involve strategies to block single pathways, such as with cyclooxygenase (COX) activity. However, the more that is learned about the consequences of COX activity, the more evident are the relationships of this enzyme to other classes of regulatory molecules such as the potent nuclear factor-kB. In light of this emerging picture, more global intervention strategies, such as with drug combinations, may be essential for success. Further basic study is essential to sort out possible molecular relationships and to permit elucidation of the most critical regulatory circuits. Given the complexity of these molecular interactions, well-designed clinical trials that specifically evaluate the precise effects of particular antiinflammatory drugs on lung carcinogenesis will also be critical to sort out the complexity and to validate successful approaches to arresting lung carcinogenesis.

Diagnostic significance of interferon-gamma in tuberculous pleural effusions

STUDY OBJECTIVES

Tuberculosis (TB), the single most frequent infectious cause of death worldwide, also is a major cause of pleural effusion, which in TB usually has lymphocytic and exudative characteristics. Differential diagnosis between TB and nontuberculous pleural effusion can be sometimes difficult, representing a critically important clinical problem.

METHODS

We studied 46 patients presenting with pleural effusion to the National Sanyo Hospital between April 2000 and January 2001 (34 men and 12 women; mean age, 64 years). Ten patients (22%) had tuberculous pleurisy, 19 patients (41%) had malignant pleuritis, and 17 patients (37%) had pleural effusion due to an etiology other than tuberculosis or cancer. Pleural fluid concentrations of four suggested markers were measured using commercially available kits.

RESULTS

The pleural fluid levels (mean +/- SE) of adenosine deaminase (83.3 +/- 18.2 U/L vs 25.8 +/- 20.4 U/L, p < 0.0001), interferon-gamma (137 +/- 230 IU/mL vs 0.41 +/- 0.05 IU/mL, p < 0.0001), immunosuppressive acidic protein (741 +/- 213 micro g/mL vs 445 +/- 180 micro g/mL, p < 0.001) and soluble interleukin 2 receptor (7,618 +/- 3,662 U/mL vs 2,222 +/- 1,027 U/mL, p < 0.0001) were significantly higher for tuberculous pleuritis than for other causes of effusion. Receiver operating characteristic analysis demonstrated that pleural fluid content INF-gamma was the best indicator of tuberculous pleurisy among four relevant biological markers.

CONCLUSIONS

INF-gamma in pleural fluid is the most sensitive and specific among four biological markers for tuberculous pleuritis. Thus, our results suggest that determination of INF-gamma at the onset of pleural effusion is informative for the diagnosis of tuberculous pleuritis. Further studies including larger numbers of patients are needed to verify this result.

Expression of ST2 in helper T lymphocytes of malignant pleural effusions

The objective of this study was to test the hypothesis that accumulated helper T lymphocytes in malignant pleural effusions may shift to T-helper type 2 (Th2) and produce soluble ST2 protein. We took samples of serum and pleural effusions (p-) from patients with carcinomatous pleurisy (CA, n = 17), tuberculous pleurisy (TB, n = 8), and congestive heart failure (HF, n = 5) and compared the concentration of cytokines or ST2. Ex vivo production of interleukin (IL)-4 and IL-10, though not that of interferon (IFN)-gamma or IL-12, from CD4+ T cells isolated from pleural effusions was higher in the CA group than in the TB or HF group. The p-ST2 concentrations were significantly higher in the CA group than in the TB or HF group, positively correlated with the percentage of pleural effusion CD4+ T cells (r = 0.432, p = 0.016) and inversely correlated with p-IFN-gamma concentrations (r = -0.423, p = 0.019). Furthermore, mRNA expression of ST2 in CD4+ T cells isolated from group CA was upregulated, compared with that in those isolated from the TB group. These results suggest that CD4+ T cells in CA shift to Th2, which can produce soluble ST2 protein, resulting in increased concentrations of p-ST2 in malignant pleural effusion.

Interleukin-7 and interleukin-12 have different effects in rescue of depressed cellular immunity: comparison of malignant and tuberculous pleural effusions

The present study attempts to determine the role of interleukin-7 (IL-7) and IL-12 in recovering the functions of the lymphocytes of malignant effusion, in terms of cytokine production, proliferation, and cytolytic activity, compared with lymphocytes from tuberculous pleural effusion. Effusion-associated lymphocytes (EAL) were isolated from tuberculous (tEAL) and malignant (mEAL) pleural effusions. The EAL proliferate response was measured after 3 days in culture. Interferon-gamma (IFN-gamma) production and cytotoxicity against K-562 cells or autologous tumor cells were assessed after 6 days in culture. It was found that the mEAL had depressed proliferation, IFN-gamma production, and cytolytic activity, as compared with tEAL. Stimulation with IL-12 plus IL-2, but not with IL-7 plus IL-2, fully restored the IFN-gamma production of mEAL to that of tEAL levels. In contrast, the proliferate response of mEAL was enhanced significantly more with IL-7 plus IL-2 than with IL-12 plus IL-2. Both the IL-7 plus IL-2 and IL-12 plus IL-2 stimulation of mEAL showed a significant increase in cytolytic activity against autologous tumor cells, although the cytolytic activity against K-562 cells did not increase. These results suggest that tEAL had a higher cellular activity than mEAL. This depressed cellular function of mEAL could be reversed with cytokines. However, different cytokines had different effects on mEAL; for example, IL-7 had a better effect in the stimulation of lymphocyte proliferation compared with IL-12, which had a better effect in driving the lymphocytes to the T helper 1 (TH1) pathway and a higher IFN-gamma production. Both IL-7 and IL-12, in the presence of IL-2, can restore the immunosuppressed cytolytic activity of the lymphocytes of malignant pleural effusion against autologous tumor.