Intrapleural nano-immunotherapy promotes innate and adaptive immune responses to enhance anti-PD-L1 therapy for malignant pleural effusion

Malignant pleural effusion (MPE) is indicative of terminal malignancy with a uniformly fatal prognosis. Often, two distinct compartments of tumour microenvironment, the effusion and disseminated pleural tumours, co-exist in the pleural cavity, presenting a major challenge for therapeutic interventions and drug delivery. Clinical evidence suggests that MPE comprises abundant tumour-associated myeloid cells with the tumour-promoting phenotype, impairing antitumour immunity. Here we developed a liposomal nanoparticle loaded with cyclic dinucleotide (LNP-CDN) for targeted activation of stimulators of interferon genes signalling in macrophages and dendritic cells and showed that, on intrapleural administration, they induce drastic changes in the transcriptional landscape in MPE, mitigating the immune cold MPE in both effusion and pleural tumours. Moreover, combination immunotherapy with blockade of programmed death ligand 1 potently reduced MPE volume and inhibited tumour growth not only in the pleural cavity but also in the lung parenchyma, conferring significantly prolonged survival of MPE-bearing mice. Furthermore, the LNP-CDN-induced immunological effects were also observed with clinical MPE samples, suggesting the potential of intrapleural LNP-CDN for clinical MPE immunotherapy.

Intrapleural Injection of Anti-PD1 Antibody: A Novel Management of Malignant Pleural Effusion

Background

Malignant tumors accompanied with malignant pleural effusion (MPE) often indicate poor prognosis. The therapeutic effect and mechanism of intrapleural injection of anti-programmed cell death protein 1 (PD1) on MPE need to be explored.

Methods

A preclinical MPE mouse model and a small clinical study were used to evaluate the effect of intrapleural injection of anti-PD1 antibody. The role of immune cells was observed via flow cytometry, RNA-sequencing, quantitative PCR, western blot, immunohistochemistry, and other experimental methods.

Results

Intrathoracic injection of anti-PD1 monoclonal antibody (mAb) has significantly prolonged the survival time of mice (P = 0.0098) and reduced the amount of effusion (P = 0.003) and the number of cancer nodules (P = 0.0043). Local CD8+ T cells participated in intrapleural administration of anti-PD1 mAb. The proportion of CD69+, IFN-γ+, and granzyme B+ CD8+ T cells in the pleural cavity was increased, and the expression of TNF-α and IL-1β in MPE also developed significantly after injection. Local injection promoted activation of the CCL20/CCR6 pathway in the tumor microenvironment and further elevated the expression of several molecules related to lymphocyte activation. Clinically, the control rate of intrathoracic injection of sintilimab (a human anti-PD1 mAb) for 10 weeks in NSCLC patients with MPE was 66.7%. Local injection improved the activity and function of patients' local cytotoxic T cells (CTLs).

Conclusions

Intrapleural injection of anti-PD1 mAb could control malignant pleural effusion and the growth of cancer, which may be achieved by enhancing local CTL activity and cytotoxicity.

Chinese medicine Xiaoshui decoction inhibits malignant pleural effusion in mice and mediates tumor-associated macrophage polarization by activating autophagy

ETHNOPHARMACOLOGICAL RELEVANCE

Xiaoshui decoction (XSD) is a traditional Chinese medicine compound prescription that has been shown to reinforce the spleen and remove the fluid retention, while being widely used in the treatment of malignant pleural effusion (MPE). We previously reported that XSD alleviates symptoms and improves the quality of life in patients with MPE; however, the mechanism employed by XSD on MPE has not yet been elucidated.

AIM OF THE STUDY

To investigate the role and mechanism of XSD in inhibiting the development of MPE, and in regulating macrophage polarization in vitro and in vivo.

MATERIALS AND METHODS

A murine MPE model was used to study the effect of XSD on MPE. Mice with MPE were randomly allocated to a control group and XSD-low-dose (1.144 g/mL), XSD-middle-dose (2.288 g/mL), XSD-high-dose (4.576 g/mL), or cisplatin groups. RAW264.7 cells were induced to form tumor-associated macrophages (TAMs) as well as M1 and M2 macrophages using different conditioned media in vitro.

RESULTS

XSD effectively inhibited MPE formation, reduced pleural permeability and angiogenesis, and prolonged mice survival. Particularly, XSD treatment induced the polarization of TAMs to the M1 phenotype in MPE. Moreover, in-vitro XSD remarkably promoted the expansion of M1 macrophages and reduced M2 macrophages by enhancing autophagy.

CONCLUSIONS

XSD inhibits MPE development and regulates macrophage polarization by activating autophagy, indicating that XSD may serve as a novel option for integrative MPE therapies.

High-throughput autoantibody analysis in malignant pleural effusion and tuberculosis pleural effusion

BACKGROUND

Malignant pleural effusion (MPE) and tuberculosis pleural effusion (TPE) are 2 kinds of common pleural diseases. Finding efficient and accurate biomarkers to distinguish the 2 is of benefit to basic and clinical research. In the present study, we carried out the first high-throughput autoantibody chip to screen the beneficial biomarker with samples of MPE and TPE and the corresponding serum.

METHODS

We collected pleural effusion and serum of patients with MPE (n = 10) and TPE (n = 10) who had been in Beijing Chao-Yang hospital from June 2013 to August 2014. Using RayBio Human Protein Array-G2 to measure the concentration of 487 defined autoantibodies.

RESULTS

Fold changes of Bcl-2-like protein 11 (BIM) autoantibody in MPE-serum/TPE-serum and MPE/TPE groups were 10 (P = .019) and 6 (P = .001); for decorin autoantibody, MPE-serum/TPE-serum ratio was 0.6 (P = .029), and MPE/TPE ratio was 0.3 (P < .001).

CONCLUSION

BIM autoantibody is a promising MPE biomarker by high-throughput autoantibody analysis in MPE and TPE.

CEA and CA 15-3 in Pleural Effusion of Advanced Breast Cancer Patients: Clinical Relevance and Diagnostic Value

Serum and pleural effusion fluid were tested for CEA concentration in 83 advanced breast cancer patients, in 43 of whom CA 15-3 was also determined.

All pleural effusions were clinically malignant. The sensitivity of the CEA test for the presence of pleural metastases was closer to that of the CA 15-3 test in effusion (0.59 and 0.79, respectively) than the sensitivity of CEA compared to CA 15-3 in serum (0.43 vs. 0.79). The use of two markers combined with cytology increased the diagnostic rate from 48% (cytologically positive) to 88% (cytologically positive and/or with one or both markers increased in effusion). A high diagnostic rate in cytologically negative effusions (65%), and in effusions presented as the sole metastatic involvement (100%), points to the clinical value of these two markers. Our results show that markers produced by pleural metastases may be secreted either into the effusion fluid or into serum, or both. This finding, as well as some other observations, are discussed in the present paper.

A Prospective Study to Evaluate a Diagnostic Algorithm for the Use of Fluid Lymphocyte Subset Analysis in Undiagnosed Unilateral Pleural Effusions

BACKGROUND

Haematological malignancy is an important cause of pleural effusion. Pleural effusions secondary to haematological malignancy are usually lymphocyte predominant. However, several other conditions such as carcinoma, tuberculosis, and chronic heart failure also cause lymphocytic effusions. Lymphocyte subset (LS) analysis may be a useful test to identify haematological malignancy in patients with lymphocytic effusions. However, research into their utility in pleural effusion diagnostic algorithms has not yet been published.

OBJECTIVES

We aimed to determine the clinical utility of pleural fluid LS analysis and whether it can be applied to a diagnostic algorithm to identify effusions secondary to haematological malignancy. The secondary aim was to evaluate the diagnostic value of pleural fluid differential cell count.

METHODS

Consecutive consenting patients presenting to our pleural service between 2008 and 2013 underwent thoracentesis and differential cell count analysis. We proposed an algorithm which selected patients with lymphocytic effusions (>50%) to have further fluid sent for LS analysis. Two independent consultants agreed on the cause of the original effusion after a 12-month follow-up period.

RESULTS

A total of 60 patients had samples sent for LS analysis. LS analysis had an 80% sensitivity (8/10) and a 100% specificity for the diagnosis of haematological malignancy. The positive and negative predictive values were 100 and 96.1%, respectively. Overall 344 differential cell counts were analysed; 16% of pleural effusions with a malignant aetiology were neutrophilic or eosinophilic at presentation. A higher neutrophil and eosinophil count was associated with benign diagnoses, whereas a higher lymphocyte count was associated with malignant diagnoses.

CONCLUSIONS

LS analysis may identify haematological malignancy in a specific cohort of patients with undiagnosed pleural effusions. A pleural fluid differential cell count provides useful additional information to streamline patient pathway decisions.

Antinuclear antibody testing in pleural fluid for the diagnosis of lupus pleuritis

We sought to determine whether measuring antinuclear antibodies (ANA) and their specificities [dsDNA, extractable nuclear antigens (ENA)] on pleural fluid may contribute to the differential diagnosis of pleural effusions. ANA were tested by indirect immunofluorescence on Hep-2 cells in the pleural fluid of 266 patients with effusions of different etiologies, including 15 lupus pleuritis. The cutoff value for diagnostic use was set at 1: 160. Pleural fluid analysis of specific autoantibodies, such as anti-dsDNA and anti-ENA, was also performed if a positive ANA test was obtained. All patients with lupus pleurisy and 16 of 251 (6.4%) patients with pleural effusions secondary to other causes were ANA positive. Fifty-six percent of the positive ANAs in non-lupus pleural fluids were due to neoplasms. The pleural fluid ANA titers were low (≤1: 80) or absent in two patients with systemic lupus erythematosus (SLE) and effusions due to other factors. Whereas ANA staining patterns in pleural fluid did not help to discriminate lupus pleuritis from non-lupus etiologies, the absence of pleural fluid anti-dsDNA or anti-ENA favored the latter. ANAs in pleural fluid provided no additional diagnostic information beyond that obtained by the measurement in serum and, therefore, these tests need not be routinely performed on pleural fluid samples. However, in patients with SLE and a pleural effusion of uncertain etiology, lack of ANAs or specific autoantibodies in pleural fluid argues against the diagnosis of lupus pleuritis.

Cytological Diagnosis of T Lymphoblastic Leukemia/Lymphoma in Patients with Pleural Effusion as an Initial Clinical Presentation: Two Case Reports of an Algorithmic Approach Using Complete Immunohistochemical Phenotyping

BACKGROUND

T cell lymphoblastic leukemia/lymphoma with the initial symptom of effusion is an uncommon condition. It may present a diagnostic challenge as lymphoblastic cells mimic normal lymphocytes under a low-power microscopic view.

CASES

Two cases are presented, both male, with the first aged 31 years and the second aged 54 years. Both initially presented with chest pain and shortness of breath, and CT scans found an anterior mediastinal mass and left pleural effusion in both subjects. Cytological smears of pleural fluid in each case showed monotonous small-to-medium-sized lymphoid cells with moderate chromatin condensation and round-to-convoluted nuclei. There were prominent apoptotic bodies and mitosis in both cases. Immunohistochemistry of cell blocks demonstrated their T cell lineage and lymphoblastic nature. Diagnosis of T cell lymphoblastic leukemia/lymphoma was determined by a 3-step algorithmic approach using complete panels of immunohistochemical markers (CD3, CD20, Ki-67, CD10, CD5, CD99, CD1a, CD34, CD4, CD8, TDT, CD7, CD2 and CD68).

CONCLUSION

An algorithmic approach based on cytological morphology and immunophenotyping is an effective way to diagnose T cell lymphoblastic leukemia/lymphoma in patients with an initial symptom of pleural effusion and insidious cytological morphology.

CD163+CD14+ macrophages, a potential immune biomarker for malignant pleural effusion

BACKGROUND

Malignant pleural effusion (MPE) is a common complication caused by malignant diseases. However, subjectivity, poor sensitivity, and substantial false-negative rates of cytology assay hamper accurate MPE diagnosis. The aim of this study was to assess whether CD163+CD14+ tumor-associated macrophages (TAMs) could be used as a biomarker for enabling sensitive and specific MPE diagnosis.

METHODS

Pleural effusion samples and peripheral blood samples were collected from 50 MPE patients and 50 non-malignant pleural effusion (NMPE) patients, respectively. Flow cytometry was performed to analyze cell phenotypes, and RT-qPCR was used to detect cytokine expression in these monocytes and macrophages. A blinded validation study (n = 40) was subsequently performed to confirm the significance of CD163+CD14+ TAMs in MPE diagnosis. Student's t test, rank sum test, and receiver operating characteristic curve analysis were used for statistical analysis.

RESULTS

Notably, CD163+CD14+ cell frequency in MPE was remarkably higher than that in NMPE (P < 0.001). In a blinded validation study, a sensitivity of 78.9 % and a specificity of 100 % were obtained with CD163+CD14+ TAMs as a MPE biomarker. In total (n = 140), by using a cutoff level of 3.65 %, CD163+CD14+ cells had a sensitivity of 81.2 % and a specificity of 100 % for MPE diagnosis. Notably, MPE diagnosis by estimating CD163+CD14+ cells in pleural effusion could be obtained one week earlier than that obtained by cytological examination.

CONCLUSIONS

CD163+CD14+ macrophages could be potentially used as an immune diagnostic marker for MPE and has better assay sensitivity than that of cytological analysis.

[Early secretory antigenic target protein-6/culture filtrate protein-10 fusion protein-specific Th1 and Th2 response and its diagnostic value in tuberculous pleural effusion]

OBJECTIVE

To detect the Th1 and Th2 cell percentage in pleural effusion mononuclear cells (PEMCs) stimulated by early secretory antigenic target protein-6 (ESAT-6)/culture filtrate protein-10 (CFP-10) fusion protein (E/C) with flow cytometry (FCM), and therefore to explore the local antigen specific Th1 and Th2 response and its diagnostic value in tuberculous pleuritis.

METHODS

Forty patients with tuberculous pleural effusion and 30 patients with malignant pleural effusion were included in this study from Sep.2008 to Mar.2009. PEMCs were isolated and cryopreserved. After resuscitation, the cells were cultured with E/C (simultaneously with positive control and negative control), and antigen-specific Th1 and Th2 cells were detected with intracellular cytokine staining of FCM. Normal distribution data using t test, abnormal distribution data using Wilcoxon test.

RESULTS

In the TB group,the medians (quartile range) of Th1 cells and Th1/Th2 ratio among PEMCs stimulated by ESAT-6/CFP-10 fusion protein were 3.06% (1.59%-6.92%) and 17 (7.38-35.53), significantly higher than those of the negative control [0.38% (0.02%-1.80%) and 3.59 (0.49-25.09)], the differences being statistically significant (Z = -5.345 and 3.314, P < 0.01). The percentage of Th2 cells [(0.22 ± 0.19)%] was also increased compared with that of the negative control [(0.10 ± 0.08)%], the difference being statistically significant (t = 4.108, P < 0.01). In the malignant effusion group, the medians (quartile range) of Th1 percentage and Th1/Th2 ratio were 0.12% (0.05%-0.39%) and 1.05 (0.25-2.52), which were significantly different as compared with those of the TB group (Z = -6.624 and -5.536, P < 0.01). The Th2 percentage in the 2 groups were (0.22 ± 0.19)% and (0.15 ± 0.02)%, respectively (t = 1.954, P > 0.05). The receiver operating characteristic curve indicated that the area under the curve (AUC), sensitivity, and specificity were 0.937, 85.4%, and 90.6% respectively for Th1 to diagnose tuberculous pleurisy. For Th1/Th2, the AUC, sensitivity, and specificity were 0.883, 81.5%, and 90.6% respectively.

CONCLUSIONS

The feature of ESAT-6/CFP-10 fusion protein-specific Th1 and Th2 response in tuberculous pleurisy was a mixed reaction of Th1 and Th2 with Th1 predominance. Th1 percentage and Th1/Th2 ratio could be diagnostic indexes for identifying tuberculous from malignant pleural effusions.

Th17/Treg imbalance in malignant pleural effusion

Both T helper IL-17-producing cells (Th17 cells) and regulatory T cells (Tregs) have been found to be increased in malignant pleural effusion (MPE). However, the possible imbalance between Th17 cells and Tregs, as well as the association of Th17/Treg and Th1/Th2 cells in MPE remains to be elucidated. The objective of the present study was to investigate the distribution of Th17 cells in relation to Tregs, as well as Th1/Th2 balance in MPE. The number of Th17, Tregs, Th1, and Th2 cells in MPE and peripheral blood was determined by using flow cytometry. The relationship among the number of Th17, Tregs, Th1, and Th2 cells was explored. It was found that the number of Th17, Tregs, Th1, and Th2 cells was all increased in MPE as compared with the corresponding peripheral blood. The number of Th17 cells was correlated negatively with Tregs in MPE, but not in blood. Th17 cells and Th17/Treg ratio were positively, and Tregs were negatively, correlated with Th1 cells, but not with either Th2 cells or Th1/Th2 ratio in MPE. This study supports earlier data that both Th17 cells and Treg are present at higher frequencies in MPE than in the autologous blood. For the first time, we show that Th17/Treg imbalance exists in MPE.

Th1 and Th2 cytokine profiles in malignant pleural effusion

BACKGROUND

The alteration of Th1 and Th2 cytokine levels is the subject of controversy in pleural effusions caused by malignancy, a situation that favors a Th2 immune response.

OBJECTIVE

To examine the different levels of IL-4 and IL-10 (Th2 cytokines), and IL-2 and interferon-γ (IFN-γ) (Th1 cytokines) in malignant and non-malignant pleural effusions.

METHOD

The cytokine levels in pleural fluid of 62 patients with malignant pleural effusion (44 with lung cancer and 18 with extrathoracic tumors), 8 with tuberculous and 8 with congestive heart failure pleural effusion were analyzed using enzyme-linked immunosorbent assays.

RESULTS

IL-2 was below the detectable concentration of the assay. A significant decrease in IFN-γ level was observed in malignant but not in congestive heart failure cases compared to tuberculous cases. IL-10 levels were higher in malignant and tuberculous pleural effusions than in congestive heart failure pleural effusions, however, this difference did not reach the significant level. IL-4 levels were also increased non-significantly in lung cancer pleural effusions compared to the other groups.

CONCLUSION

Our results show a wide variation in IL-4, IL-10, and IFN-γ levels in malignant pleural effusions, a pattern which was not convincing enough to differentiate the cause of effusion.

Evaluation of the phenotype pattern of macrophages isolated from malignant and non-malignant pleural effusions

Macrophages are among the infiltrate components of most malignant tumors. Tumor-associated macrophages (TAMs) may secrete a variety of humoral factors, which promote or inhibit tumor growth. In general, depending on their activation pathway, macrophages exhibit two different patterns of phenotype, M1 or M2. It is assumed that TAMs comprise pattern M2. In the malignant pleural effusion, macrophages are a frequent component of cytological evaluation. In this microenvironment, TAMs could be involved in the development of immunity. The phenotype of macrophages represented in malignant and non-malignant pleural effusions is unknown. In this study, macrophages were isolated from 38 pleural effusions (15 malignant and 23 non-malignant) and the expression of a variety of immune mediators and their receptors was assessed to determine the type of activation (M1 vs. M2). The expression of mRNA was analyzed for IL-1β, IL-4, IL-6, IL-10, IL-11, IL-18, TNFα, TGFβ1, IL1R1, IL1RAP, TLR2, TLR4, VLA4, CD62L, MMP2, MMP9, VEGFA, PDGFA, and PDGFB. In immunohistochemical evaluation, the expressions of CD68, mesothelin, MAC387, IL-1β, IL-6, IL-10, IL-12, TNFα, and CD105 were assessed. The cytoplasmic expression of IFNγ, TNFα, IL-6, and IL-10 and the surface expression of CD11a, CD14, CD15, CD16, CD23, CD25, CD45, CD54, CD62L, CD69, VLA2, VLA3, VLA4, VLA6, TLR2, TLR4, and CCR7 were tested using flow cytometry. In supernatants from macrophages cultures, TNFα, IL-1β, IL-6, IL-8, IL-10, IL-12, MCP1, and VEGF were investigated by cytometric beads array method (CBA flex sets) and TGFβ1 by ELISA. Our results indicate that macrophages from malignant and non-malignant pleural effusions differ from each other and suggest that macrophages isolated from non-malignant effusions show a pattern comparable to M1 while those isolated from malignant effusions express similarity to M2 phenotype, but they have not shown a classical M2 pattern.

CD39+ regulatory T cells suppress generation and differentiation of Th17 cells in human malignant pleural effusion via a LAP-dependent mechanism

BACKGROUND

Both regulatory T cells (Tregs) and T helper IL-17-producing cells (Th17 cells) have been found to be involved in human malignancies, however, the possible implication of Tregs in regulating generation and differentiation of Th17 cells in malignant pleural effusion remains to be elucidated.

METHODS

The numbers of both CD39(+)Tregs and Th17 cells in malignant pleural effusion and peripheral blood from patients with lung cancer were determined by flow cytometry. The regulation and mechanism of Tregs on generation and differentiation of Th17 cells were explored.

RESULTS

Both CD39(+)Tregs and Th17 cells were increased in malignant pleural effusion when compared with blood, and the numbers of CD39(+)Tregs were correlated negatively with those of Th17 cells. It was also noted that high levels of IL-1β, IL-6, and TGF-β1 could be observed in malignant pleural effusion when compared the corresponding serum, and that pleural CD39(+)Tregs could express latency-associated peptide on their surface. When naïve CD4(+) T cells were cocultured with CD39(+)Tregs, Th17 cell numbers decreased as CD39(+)Treg numbers increased, addition of the anti-latency-associated peptide mAb to the coculture reverted the inhibitory effect exerted by CD39(+)Tregs.

CONCLUSIONS

Therefore, the above results indicate that CD39(+)Tregs inhibit generation and differentiation of Th17 cells via a latency-associated peptide-dependent mechanism.

Surface-bound TGF-beta1 on effusion-derived exosomes participates in maintenance of number and suppressive function of regulatory T-cells in malignant effusions

BACKGROUND

This study analysed the contribution of malignant-effusion derived exosomes (Eff-Ex) to the number and function of regulatory T-cells (Treg) in malignant effusions.

PATIENTS AND METHODS

Eff-Ex were collected from the malignant effusions of 24 cancer patients. Peripheral blood mononuclear cells (PBMCs) were co-cultured with different concentrations of Eff-Ex. FOXP3(+) CD4(+) T-cells were defined as Treg. Expression of molecules on Eff-Ex was determined by flow cytometric analysis.

RESULTS

The number of Treg decreased daily in parallel with the FOXP3 expression level. Purified Eff-Ex prevented the decreases in both Treg number and FOXP3 expression levels in a dose-dependent manner. Pre-treatment of Eff-Ex with a neutralizing mAb against TGF-β1 significantly reduced these effects and the suppressive function of Treg.

CONCLUSION

Elimination of Eff-Ex or control of Eff-Ex expressing TGF-β1 may be new therapeutic strategies in immunotherapy for advanced cancer patients with malignant effusions.

HM1.24 (CD317) is a novel target against lung cancer for immunotherapy using anti-HM1.24 antibody

HM1.24 antigen (CD317) was originally identified as a cell surface protein that is preferentially overexpressed on multiple myeloma cells. Immunotherapy using anti-HM1.24 antibody has been performed in patients with multiple myeloma as a phase I study. We examined the expression of HM1.24 antigen in lung cancer cells and the possibility of immunotherapy with anti-HM1.24 antibody which can induce antibody-dependent cellular cytotoxicity (ADCC). The expression of HM1.24 antigen in lung cancer cells was examined by flow cytometry as well as immunohistochemistry using anti-HM1.24 antibody. ADCC was evaluated using a 6-h (51)Cr release assay. Effects of various cytokines on the expression of HM1.24 and the ADCC were examined. The antitumor activity of anti-HM1.24 antibody in vivo was examined in SCID mice. HM1.24 antigen was detected in 11 of 26 non-small cell lung cancer cell lines (42%) and four of seven (57%) of small cell lung cancer cells, and also expressed in the tissues of lung cancer. Anti-HM1.24 antibody effectively induced ADCC in HM1.24-positive lung cancer cells. Interferon-beta and -gamma increased the levels of HM1.24 antigen and the susceptibility of lung cancer cells to ADCC. Treatment with anti-HM1.24 antibody inhibited the growth of lung cancer cells expressing HM1.24 antigen in SCID mice. The combined therapy with IFN-beta and anti-HM1.24 antibody showed the enhanced antitumor effects even in the delayed treatment schedule. HM1.24 antigen is a novel immunological target for the treatment of lung cancer with anti-HM1.24 antibody.

The contribution of vascular endothelial growth factor to the induction of regulatory T-cells in malignant effusions

It has been suggested that immunosuppressive cytokines such as transforming growth factor beta (TGF-beta) and interleukin 10 play an important role in the induction and/or maintenance of regulatory T-cells (Tregs) in patients with cancer. In the present study, whether or not vascular endothelial growth factor (VEGF) contributes to the induction and/or maintenance of Tregs was examined, because of experience with a patient in whom a positive correlation between VEGF concentration and the percentage of Tregs (% Tregs) among the total CD4(+) T-cells in the pleural effusion was found during dendritic cell activated lymphocyte therapy. CD4(+)CD25(high) T-cells were estimated as Tregs in the present study. In an in vitro experimental system, VEGF-containing malignant effusions increased the % Tregs in autologous peripheral blood mononuclear cells (PBMCs), which could be suppressed by the addition of a humanized monoclonal anti-VEGF antibody (bevacizumab [Avastin]). When VEGF-producing hepatic carcinoma cells were mix-cultured with PBMCs, the % Tregs increased and this increase was also suppressed by the addition of bevacizumab. Whether or not bevacizumab can affect the % Tregs of PBMCs in patients with colon cancer was also examined. Three out of four patients showed a significant decrease of the % Tregs after intravenous injection of bevacizumab. Interestingly, the expression of VEGF receptor-2 (VEGFR-2) was higher in Tregs than in other CD4(+) T-cells. Taken together, the data presented here indicate a contribution of VEGF to induction and/or maintenance of Tregs in patients with cancer.

Malignant and tuberculous pleural effusions: immunophenotypic cellular characterization

INTRODUCTION AND OBJECTIVES

Tuberculosis and cancer are the main causes of pleural effusion. Pleural involvement is associated with migration of immune cells to the pleural cavity. We sought to characterize the immunophenotype of leukocytes in the pleural effusion and peripheral blood of patients with tuberculosis or malignancy.

METHODS

Thirty patients with tuberculosis (14) or malignancy (16) were studied. A control group included 20 healthy blood donors.

RESULTS

Malignant phycoerythrin pleural effusions showed higher percentages of CD3, CD4, CD3CD45RO, and CD20CD25 lymphocytes and lower percentages of CD3CD25 and CD20HLA-DR when compared to PB lymphocytes. Compared to PB, tuberculous effusions had a higher percentage of lymphocytes that co-expressed CD3, CD4, CD3CD45RO, CD3TCRalphabeta, CD3CD28, and CD20 and a lower percentage of CD14, CD8 and CD3TCRgammadelta-positive lymphocytes. Malignant effusions presented higher expression of CD14 whereas tuberculous effusions had higher expression of CD3 and CD3CD95L. Peripheral blood cells from tuberculosis patients showed higher expression of CD14, CD20CD25 and CD3CD95L. Compared with the control cells, tuberculosis and cancer peripheral blood cells presented a lower percentage of CD3CD4 and CD3CD28-positive cells as well as a higher percentage of CD3CD8, CD3CD25 and CD3CD80-positive cells.

CONCLUSIONS

Tuberculous and malignant peripheral blood is enriched with lymphocytes with a helper/inducer T cell phenotype, which are mainly of memory cells. CD14-positive cells were more frequently found in malignant effusions, while CD3-positive cells expressing Fas ligand were more frequently found in tuberculous effusions.

Dose-finding study of anti-CD25 antibody for targeting regulatory T cells in locoregional immunotherapy of malignant effusion

Effects of low-dose anti-CD25 antibody on targeting regulatory T (Treg) cells in vitro and in vivo were investigated. Human-mouse chimeric anti-CD25 monoclonal antibody basiliximab was administered into the effusion cavity, followed by locoregional immunotherapy using OK-432 on day 7. Peripheral blood mononuclear cells and effusion lymphocytes (ELs) were collected before and after the basiliximab administration and subjected to further investigations. Surface phenotypes, IFN-gamma production, cytotoxic activity and foxp3 expression of ELs were assessed by flow cytometry, ELISA, 51Cr-releasing assay, and RT-PCR analysis, respectively. We observed that a low concentration of 0.01 microg/ml basiliximab effectively targeted CD4+CD25(bri) Treg cells while preserving CD4+CD25(dim) activated T cells in vitro. This concentration of basiliximab significantly augmented interferon (IFN)-gamma production of ELs when interleukin (IL)-2 was added on day 0 or on day 1 after basiliximab. In the clinical study, intracavitary administration of basiliximab on day 0 followed by OK-432 on day 7 was as safe, well-tolerated, and effective as using OK-432 alone, and a low-dose of 0.002-0.005 mg/kg basiliximab could target CD4+CD25(bri) cells for at least 3 days while relatively preserving CD4+CD25(dim) cells. Foxp3 expression of ELs was not changed definitely by the intracavitary basiliximab. These results suggest that low-dose basiliximab can target Treg cells in vitro and in vivo, and subsequently augment the activation of ELs. Locoregional immunotherapy of malignant effusion using the Treg cell-conditioning regimen with low-dose basiliximab followed by OK-432 administration on day 0 or on day 1 should be evaluated for clinical efficacy in the next phase II trial.

Detection of B cell lymphoma involvement in T cell-rich serous fluid by immunoglobulin gene rearrangement: a report of 2 cases

BACKGROUND

Cytology, flow cytometry and gene rearrangement studies are methods to detect lymphoma involvement of body fluid. The cytology of the effusion is equivocal for lymphoma involvement.

CASES

We report 2 cases of diffuse large B cell lymphoma with massive lymphocyte predominant serous fluid, ascites in one case and pleural effusion in the other. Immunophenotypic analysis by flow cytometry showed that lymphoid cells express only T cell markers. Lymphoma involvement of effusion was confirmed by immunoglobulin gene rearrangement detected by polymerase chain reaction.

CONCLUSION

Our case demonstrated the value of gene rearrangement study in establishing diagnosis of equivocal cases.

Diagnostic considerations in prolymphocytes in pleural fluid: a case report

BACKGROUND

Prolymphocytes are nucleolated cells that are the defining features of the 2 chronic lymphoproliferative disorders, prolymphocytic leukemia (PLL) and chronic lymphocytic leukemia (CLL) with increased prolymphocytes. Prolymphocytes appear relatively unfamiliar in cytopathology practice, and, particularly when present in body fluids, may resemble blasts or adult T-cell leukemia/ lymphoma (ATLL) cells.

CASE

A 32-year-old man, referred to us with a diagnosis of acute leukemia, presented with shortness of breath for 2 months and loss of appetite for 3 months. He had enlarged liver and spleen, 6 and 8 cm, respectively, below the costal margin and pleural effusion. The raised total leukocyte count chiefly comprised prolymphocytes that, especially in the pleural fluid, had prominent nucleoli and significant pleomorphism, raising the possibility of blasts or ATLL.

CONCLUSION

Prolymphocytes in body fluids can be misinterpreted as blasts or even ATLL cells. Better awareness among cytopathologists about prolymphocytes and the disease states in which they occur, as well as insistence, in a clinical setting of leukemia, on interpreting the pleural fluid in relation to the clinical and laboratory findings, especially those of the peripheral blood and bone marrow, can prevent misdiagnosis. Equally importantly, immunophenotyping must be done in such situations.

[Impact of intrapleural hyperthermic perfusion on immunologic reaction state of cytokines TH1/TH2 of lung carcinoma patients with malignant pleural effusion]

BACKGROUND & OBJECTIVE

Intrapleural hyperthermic perfusion is the distinctive therapy of malignant pleural effusion (MPE) caused by lung carcinoma. The expression pattern of T helper type 1 (Th1)/Th2 is an important index that reflects antitumor immunologic function. This study was to evaluate the therapeutic effect of intrapleural hyperthermic perfusion on MPE, and to investigate the impact of intrapleural hyperthermic perfusion on the immunologic reaction state of lung carcinoma patients with MPE by observing the expression pattern of cytokines Th1/Th2.

METHODS

A total of 24 lung carcinoma patients with MPE underwent intrapleural hyperthermic perfusion with 43 celsius warmed normal saline for 60 min under video-assisted thoracoscopic surgery (VATS). The responses of pleural effusion, adverse events, life quality and survival time were observed. The concentrations of Th1/Th2-related cytokines interferon-gamma (IFN-gamma), interleukin-2 (IL-2)/IL-4, and IL-10 in peripheral blood and pleural effusion were detected by ELISA, and their mRNA expression was detected by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Neither operation-related death nor postoperative complication occurred. The total response rate of pleural effusion control was 100%, including 23 cases of complete remission (CR) and 1 case of partial remission (PR). No recurrence of MPE occurred. The quality of life of all patients had been improved. The median survival time was 18.3 months. The 1-and 2-year survival rates were 91.7% and 16.7%. The concentrations and positive rates of IL-2 and IFN-gamma were significantly lower and those of IL-4 and IL-10 were significantly higher in peripheral blood and pleural effusion before hyperthermia than in those after hyperthermia (P<0.05).

CONCLUSIONS

Intrapleural hyperthermic perfusion under VATS is a safe and effective treatment for MPE caused by lung carcinoma. It can convert the predominant state of Th2 cytokines in lung carcinoma patients with MPE to that of Th1 cytokines.

A phase I clinical trial of single-dose intrapleural IFN-beta gene transfer for malignant pleural mesothelioma and metastatic pleural effusions: high rate of antitumor immune responses

PURPOSE

This phase 1 dose escalation study evaluated the safety and feasibility of single-dose intrapleural IFN-beta gene transfer using an adenoviral vector (Ad.IFN-beta) in patients with malignant pleural mesothelioma (MPM) and metastatic pleural effusions (MPE).

EXPERIMENTAL DESIGN

Ad.IFN-beta was administered through an indwelling pleural catheter in doses ranging from 9 x 10(11) to 3 x 10(12) viral particles (vp) in two cohorts of patients with MPM (7 patients) and MPE (3 patients). Subjects were evaluated for (a) toxicity, (b) gene transfer, (c) humoral, cellular, and cytokine-mediated immune responses, and (d) tumor responses via 18-fluorodeoxyglucose-positron emission tomography scans and chest computed tomography scans.

RESULTS

Intrapleural Ad.IFN-beta was generally well tolerated with transient lymphopenia as the most common side effect. The maximally tolerated dose achieved was 9 x 10(11) vp secondary to idiosyncratic dose-limiting toxicities (hypoxia and liver function abnormalities) in two patients treated at 3 x 10(12) vp. The presence of the vector did not elicit a marked cellular infiltrate in the pleural space. Intrapleural levels of cytokines were highly variable at baseline and after response to gene transfer. Gene transfer was documented in 7 of the 10 patients by demonstration of IFN-beta message or protein. Antitumor immune responses were elicited in 7 of the 10 patients and included the detection of cytotoxic T cells (1 patient), activation of circulating natural killer cells (2 patients), and humoral responses to known (Simian virus 40 large T antigen and mesothelin) and unknown tumor antigens (7 patients). Four of 10 patients showed meaningful clinical responses defined as disease stability and/or regression on 18-fluorodeoxyglucose-positron emission tomography and computed tomography scans at day 60 after vector infusion.

CONCLUSIONS

Intrapleural instillation of Ad.IFN-beta is a potentially useful approach for the generation of antitumor immune responses in MPM and MPE patients and should be investigated further for overall clinical efficacy.

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.

[The disappearance of CD20 positive lymphocytes in the pleural effusion after intrapleural application of rituximab]

A 63 year old woman with non-Hodgkin lymphoma presented with unilateral pleural effusion, which when aspirated revealed CD19 and CD20 positive malignant cells. Prior to this, the patient had received several lines of chemotherapy (CHOP, VAD, FED) with no effect on pleural effusion. Repeated percutaneous drainage procedures were unable to control the effusion either. Rituximab was therefore instilled in a dose escalating manner via repeated pleurocenteses. Fifty days after the application of rituximab, pleural effusion was still present but reduced in size. Flow cytometry and immunocytochemistry performed on the same day showed CD19 positive cells which were lacking CD20 epitope, which could be explained by either engagement or destruction of the CD20 epitope upon interaction with rituximab making the detection of the CD20 molecule impossible by routine flow cytometry. What is especially interesting is the fact that even 50 days after the application of rituximab intrapleurally no new CD20 positive cells could be found in the pleural effusion by immunochemistry or flow cytometry, opening an interesting issue concerning the length of rituximab's activity when applied locally. Although our patient had no adverse effects, further analysis of rituximab's activity and safety when applied intrapleurally is warranted.

Flow cytometric immunphenotyping of epithelial cancer cells in effusions—Technical considerations and pitfalls

BACKGROUND

Data regarding the role of flow cytometry (FCM) in the characterization of malignant effusions are limited to date. In the present study, we optimized the conditions for FCM immunphenotyping of effusions using a four-color analysis and investigated aspects related to the advantages and limitations of this method in this setting.

METHODS

FCM analysis optimization for the study of epithelial cells was undertaken using five carcinoma cell lines, and subsequently applied to malignant pleural and peritoneal effusions using antibodies against epithelial and mesothelial markers (Ber-EP4 and EMA), CD138, and integrin subunits. FCM of frozen versus fresh specimens and the performance of FCM compared to immunhistochemistry were evaluated.

RESULTS

FCM optimization was achieved and applied to clinical specimens, with resulting detection of epithelial markers and adhesion molecules on cancer cells. Frozen clinical specimens and cell lines showed reduced CD138 expression compared to fresh specimens, with conservation of the remaining epitopes. FCM generally showed comparable performance to immunhistochemistry.

CONCLUSIONS

FCM is an effective method for characterization of cancer cells in clinical effusion specimens in both the diagnostic and research setting, and is comparable to immunhistochemistry in terms of sensitivity and specificity, with the additional advantage of providing quantitative data. The majority of epitopes are conserved in frozen cells, but a minority may be lost, suggesting that the thorough testing of each antibody in both conditions is mandatory.

Potential role of natural killer cells in controlling growth and infiltration of AIDS-associated primary effusion lymphoma cells

Natural killer (NK) cells are an important component of the innate immune response against microbial infections and tumors. Direct involvement of NK cells in tumor growth and infiltration has not yet been demonstrated clearly. Primary effusion lymphoma (PEL) cells were able to produce tumors and ascites very efficiently with infiltration of cells in various organs of T-, B- and NK-cell knock-out NOD/SCID/gammac(null) (NOG) mice within 3 weeks. In contrast, PEL cells formed small tumors at inoculated sites in T- and B-cell knock-out NOD/SCID mice with NK-cells while completely failing to infiltrate into various organs. Immunosupression of NOD/SCID by treatment with an antimurine TM-beta1 antibody, which transiently abrogates NK cell activity in vivo, resulted in enhanced tumorigenicity and organ infiltration in comparison with non-treated NOD/SCID mice. Activated human NK cells inhibited tumor growth and infiltration in NOG mice. Our results suggest that NK cells play an important role in growth and infiltration of PEL cells, and activated NK cells could be a promising immunotherapeutic tool against tumor or virus-infected cells either alone or in combination with conventional therapy. The rapid and efficient engraftment of PEL cells in NOG mice also suggests that this new animal model could provide a unique opportunity to understand and investigate the mechanism of pathogenesis and malignant cell growth.

Elevated pleural fluid RCAS1 is a diagnostic marker and outcome predictor in lung cancer patients

RCAS1, a type II membrane protein also secreted in soluble form, may be important in tumor cell evasion of immune surveillance and contribute to the aggressiveness of human tumors. We examined the implications of elevated pleural fluid RCAS1 at the onset of effusion in lung cancer patients. Of 102 patients presenting with pleural effusion, 59 proved to have a malignant effusion and 43, nonmalignant. Malignant effusions exhibited higher RCAS1 concentrations than nonmalignant effusions (mean +/- SD; 36.3 +/- 114 vs. 2.7 +/- 1.8 U/ml; p=0.014). Lung cancer patients with pleural fluid RCAS1 concentrations below 15 U/ml had a longer mean survival than those with higher concentrations (4.7 vs. 1.7 months; p<0.05). By multivariate analysis, pleural fluid RCAS1 was an independent prognostic factor in lung cancer patients with effusion. In conclusion, RCAS1 determination at onset of pleural effusion is informative for both diagnosis and outcome prediction in lung cancer patients.

Mesothelioma environment comprises cytokines and T-regulatory cells that suppress immune responses

Malignant mesothelioma is a cancer with dismal prognosis. The objective of the present study was to address the role of the immune system, tumour micro-environment and potential immunosuppression in mesothelioma. Expression profiles of 80 cytokines were determined in the supernatant of mesothelioma cell lines and the original patient's pleural effusion. Influx of immune effector cells was detected by immunohistochemistry. Angiogenin, vascular endothelial growth factor, transforming growth factor-beta, epithelial neutrophil-activating protein-78 and several other proteins involved in immune suppression, angiogenesis and plasma extravasation could be detected in both supernatant and pleural effusion. Surrounding stroma and/or infiltrating cells were the most likely source of hepatocyte growth factor, macrophage inflammatory protein (MIP)-1delta, MIP-3alpha, neutrophil-activating peptide-2, and pulmonary and activation-regulated chemokine that can cause leukocyte infiltration and activation. There was a massive influx of CD4+ and CD8+ T-lymphocytes and macrophages, but not of dendritic cells, in human mesothelioma biopsies. It was further demonstrated that human mesothelioma tissue contained significant amounts of Foxp3+CD4+CD25+ regulatory T-cells. When these CD25+ regulatory T-cells were depleted in an in vivo mouse model, survival increased. Mesothelioma is infiltrated by immune effector cells but also contains cytokines and regulatory T-cells that suppress an efficient immune response. Immunotherapy of mesothelioma might be more effective when combined with drugs that eliminate or control regulatory T-cells.

Expression of HLA-G in malignant mesothelioma and clinically aggressive breast carcinoma

The aim of the present study was to evaluate HLA-G expression in breast carcinoma and malignant mesothelioma (MM). Malignant breast carcinoma effusions (46) and corresponding solid tumors (39) and 104 MM (26 effusions, 78 solid tumors) were analyzed using immunohistochemistry (IHC). HLA-G protein and mRNA expression were further studied using immunoblotting (IB) and RT-PCR. HLA-ABC expression was analyzed using flow cytometry (FCM). IHC showed predominantly focal HLA-G expression in 12 of 46 (26%) breast carcinoma effusions and 16 of 39 (41%) solid lesions. In MM, 20 of 78 (26%) solid lesions and 14 of 26 (54%) effusions were focally HLA-G positive. Expression in MM was higher in effusions (p=0.008). IB showed more frequent HLA-G expression in MM compared with breast carcinoma effusions, while RT-PCR showed HLA-G mRNA expression in both tumors. FCM showed conserved HLA-ABC expression in 15 of 15 effusions. Breast cancer patients with HLA-G-positive tumor cells had shorter disease-free survival (mean 37 vs 85, median 25 vs 31 months), though not significantly (p=0.14). In conclusion, HLA-G is focally expressed in MM and breast carcinoma, while HLA-ABC expression is conserved. However, the up-regulated expression of HLA-G in MM effusions and its possible association with shorter disease-free survival in advanced stage of breast carcinoma suggest a possible role in immune response evasion in some tumors.

[Determination and significance of interleukin-16 in tuberculous and malignant pleural effusion]

OBJECTIVE

Interleukin-16 (IL-16) is a chemoattractant of CD4+ lymphocytes, and it has been implicated in the pathogenesis of various inflammatory diseases. The aim of the present study was to measure IL-16 in pleural effusions caused by tuberculosis and malignancy and its relationship with cell and differential counts as well as lymphocyte subsets.

METHODS

Pleural effusion and venous blood samples were collected from 32 patients with tuberculous pleuritis and 30 lung cancer patients with malignant effusion. Analysis of pleural effusion for total leukocytes and cell differentials of leukocytes was performed. Three-color flow cytometry was performed to determine T lymphocyte subsets in cell pellets of pleural effusion. The concentration of IL-16 in cell-free supernatants of pleural effusion and sera was measured by a sandwich enzyme-linked immunosorbent assay.

RESULTS

In all the studied patients, the level of IL-16 was significantly higher in pleural effusion than in serum. The levels of IL-16 were significantly higher in tuberculous than in malignant effusions. In pleural effusion, positive correlations were found between the IL-16 levels and total cell counts, lymphocytes, CD3+ T cells, as well as CD4+ T cells.

CONCLUSIONS

Compared to malignant pleural effusion, IL-16 appeared to be increased in tuberculous pleural effusion. The pleural effusion IL-16 levels were positively related to the numbers of CD4+ T cells, suggesting that IL-16 might be capable of inducing CD4+ T cell infiltration into pleural space.

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.

CD4+CD25+ regulatory T lymphocytes in malignant pleural effusion

BACKGROUND

Active suppression by CD4(+)CD25(+) regulatory T lymphocytes plays an important role in the downregulation of T-cell responses to foreign and self-antigens.

OBJECTIVE

To analyze whether the CD4(+)CD25(+) regulatory T lymphocytes exist and function normally in malignant pleural effusion.

METHODS

The percentages of CD4(+)CD25(+) T lymphocytes in pleural effusion and peripheral blood from patients with lung cancer with malignant effusion, pleural lavage and peripheral blood from patients with lung cancer without effusion, and peripheral blood from healthy control subjects were determined by flow cytometry. The expressions of forkhead transcription factor Foxp3 and cytotoxic lymphocyte-associated antigen-4 were also examined. CD4(+)CD25(+) and CD4(+)CD25(-) T cells from pleural effusion and peripheral blood were isolated, and were cultured to observe the effects of CD4(+)CD25(+) cells on proliferation response of CD4(+)CD25(-) T cells in vitro.

MAIN RESULTS

There were increased numbers of CD4(+)CD25(+) T cells in malignant pleural effusion from patients with lung cancer compared with pleural lavage from patients with lung cancer without pleural effusion, and that these cells have constitutive high-level expression of Foxp3 and cytotoxic lymphocyte-associated antigen-4. Furthermore, CD4(+)CD25(+) T cells mediate potent inhibition of proliferation response of CD4(+)CD25(-) T cells, and anticytotoxic lymphocyte-associated antigen-4 monoclonal antibody could reduce the inhibitory activity of CD4(+)CD25(+) T cells.

CONCLUSIONS

The increased CD4(+)CD25(+) T cells found in malignant pleural effusion express high levels of Foxp3 transcription factor and potently suppress the proliferation of CD4(+)CD25(-) T cells, and cytotoxic lymphocyte-associated antigen-4 is involved in the suppressive activity of pleural CD4(+)CD25(+) T cells.

Regulatory T cells and cytokines in malignant pleural effusions secondary to mesothelioma and carcinoma

Immunotherapy against a variety of malignancies, including pleural-based malignancies, has shown promise in animal models and early human clinical trials, but successful efforts will need to address immunosuppressive factors of the tumor and host, particularly certain cytokines and CD4(+) CD25(+) regulatory T cells (Treg). Here, we evaluated the cellular and cytokine components of malignant pleural effusions from 44 patients with previously diagnosed mesothelioma, non-small cell lung cancer (NSCLC), or breast cancer and found significant differences in the immune profile of pleural effusions secondary to mesothelioma vs. carcinoma. Although a high prevalence of functionally suppressive CD4(+) CD25(+) T cells was found in carcinomatous pleural effusions, mesothelioma pleural effusions contained significantly fewer CD4(+) CD25(+) T cells. Activated CD8(+) T cells in pleural fluid were significantly more prevalent in mesothelioma than carcinoma. However, there is clear patient-to-patient variability and occasional mesothelioma patients with high percentages of CD4(+) CD25(+) pleural effusion T cells and low percentages of CD8(+) CD25(+) pleural effusion T cells can be identified. Mesothelioma pleural effusions contained the highest concentrations of the immunosuppressive cytokine transforming growth factor (TGF)-beta. Thus, the contribution of cellular and cytokine components of immunosuppression associated with malignant pleural effusions varies by tumor histology and by the individual patient. These results have implications for the development of immunotherapy directed to the malignant pleural space, and suggest the need to tailor immunotherapy to overcome immunosuppressive mechanisms in tumor environments.

HLA class I, NKG2D, and natural cytotoxicity receptors regulate multiple myeloma cell recognition by natural killer cells

The role of natural killer (NK) cells in multiple myeloma is not fully understood. Here, NK susceptibility of myeloma cells derived from distinct disease stages was evaluated in relation to major histocompatibility complex (MHC) class I, MHC class I chain-related protein A (MICA), MHC class I chain-related protein B (MICB), and UL16 binding protein (ULBP) expression. MHC class I molecules were hardly detectable on bone marrow cells of early-stage myeloma, while late-stage pleural effusion-derived cell lines showed a strong MHC class I expression. Conversely, a high MICA level was found on bone marrow myeloma cells, while it was low or not measurable on pleural effusion myeloma cells. The reciprocal surface expression of these molecules on bone marrow- and pleural effusion-derived cell was confirmed at mRNA levels. While bone marrow-derived myeloma cells were readily recognized by NK cells, pleural effusion-derived lines were resistant. NK protection of pleural effusion cells was MHC class I dependent. Receptor blocking experiments demonstrated that natural cytotoxicity receptor (NCR) and NK receptor member D of the lectin-like receptor family (NKG2D) were the key NK activating receptors for bone marrow-derived myeloma cell recognition. In ex vivo experiments patient's autologous fresh NK cells recognized bone marrow-derived myeloma cells. Our data support the hypothesis that NK cell cytotoxicity could sculpture myeloma and represents an important immune effector mechanism in controlling its intramedullary stages.

Simultaneous measurement of T-helper 1 cytokines in tuberculous pleural effusion

OBJECTIVE

Tuberculosis, the leading cause of death among infectious diseases worldwide, is a major cause of lymphocytic exudative pleural effusion. T-helper 1 cytokines, including interferon-gamma (IFN-gamma), interleukin (IL)-12p40 and IL-18 are predominantly associated with cell-mediated immune responses, and play an important role in immunity to Mycobacterium tuberculosis.

DESIGN

We studied 55 patients presenting with pleural effusion at the National Sanyo Hospital between April 2000 and September 2001 (42 men and 13 women; mean age 67 years). Twenty patients (36%) had tuberculous pleurisy, while 18 (33%) had malignant effusions and 17 (31%) had an effusion with another aetiology. Pleural fluid concentrations of IL-12p40 and IL-18 as well as IFN-gamma measured by enzyme-immunoassays.

RESULTS

Concentrations of all three cytokines were significantly higher in tuberculous than other pleural effusions. Significant correlations were evident between IFN-gamma and IL-12. We found particularly high concentrations of IL-12p40 and IFN-gamma in tuberculous patients with high fever.

CONCLUSION

The results indicate that T-helper 1 cytokines are involved in intrapulmonary cellular immune responses to M. tuberculosis, and suggest that the interactions between them may play an important role in the pathogenesis and severity of the pleural effusion. Understanding the development of this response may enhance our understanding of the pathogenesis of tuberculous pleural effusion and suggest new therapies.

Combined immunotherapy with intracavital injection of activated lymphocytes, monocyte-derived dendritic cells and low-dose OK-432 in patients with malignant effusion

We have conducted a pilot study with combined immunotherapy using autologous lymphocytes activated ex vivo and monocyte-derived dendritic cells in combination with low-dose OK-432, a streptococcal preparation, in five patients with peritoneal or pleural carcinomatosis who were resistant to standard chemotherapy. All patients were given 3 to 10 courses of the combined immunotherapy. No severe adverse reactions occurred. Effusion production was decreased in all of the patients. Significant decreases in tumor markers of both effusions and sera as well as effusion volume occurred in all of the patients. Cytological examinations revealed a marked decrease or disappearance of cancer cells in those effusions. Three patients showed increase in IFN-gamma levels in the effusions. The overall prognosis of the patients was acceptable and the mean survival time was more than 9 months. The locoregional immunotherapy seems to be encouraging in view of therapeutic modality in patients who are resistant to standard chemotherapy. Our study provides a new protocol for immunotherapy and warrants further phase I/II clinical study for chemo-resistant patients with malignant effusion.

Matrix metalloproteinases production in malignant pleural effusions after talc pleurodesis

In this study we have evaluated the modifications of matrix metalloproteinases (MMPs) in malignant pleural fluids taken from patients suffering from lung cancer and treated with intrapleural talc instillation to induce pleurodesis. Furthermore, we have analysed the variations of some inflammatory mediators (C-reactive protein, alpha-1 antitrypsin) and of a protein (plasminogen) involved in MMP activation. In all patients the clinical improvement after talc pleurodesis was followed by a reduction in MMP-1, TIMP-1, C-reactive protein, alpha-1 antitrypsin and plasminogen activity. Furthermore, MMP-9 levels were variable; in fact, in some patients they were high at the beginning of treatment, in others they increased a few days after pleurodesis induction. These inhibitory effects of talc on MMP-1 and inflammatory mediators associated with the reduction of pleural effusion could constitute an effective means to evaluate the evolution of the treatment.

Analysis of the immunological microenvironment at the tumor site in patients with non-small cell lung cancer

BACKGROUND AND AIMS

Inactivation of tumor-infiltrating lymphocytes by immunomodulating cytokines shed by tumor cells into the tumor local microenvironment might be a potential escape strategy of various tumors from immune-immediate killing. Here, we provide an analysis of the cytokine profile at the tumor site in patients with non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

Using in situ hybridization (ISH), we determined the mRNA expression in lymphocytes and tumor cells for IL-2, INF-gamma, IL-12 (p40), IL-18, IL-4, IL-10, TGF-beta1, IL-1, IL-3, IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF), TNF-alpha, and TGF-alpha in five fresh pleural effusion samples and 18 tumor tissue samples of patients with NSCLC.

RESULTS

In pleural effusion as well as in tumor tissue of NSCLC patients, the mRNA expression of IL-4, IL-10, TGF-alpha, and TGF-beta1 was significantly higher than that of IL-2, IL-12, IL-18 and INF-gamma. In contrast, the analysis of tuberculosis pleural effusion samples revealed lower mRNA levels for all cytokines and did not show any significant difference among them.

CONCLUSION

The predominant mRNA expression of type II and immunosuppressive cytokines in pleural effusion and tumor tissue of NSCLC patients mirrors an immunosuppressive state in the immunological microenvironment. The present study may, therefore, help to elucidate mechanisms of tumor escape and contribute to the development of an effective immunomodulatory treatment of NSCLC.

Elevated serum cytokine levels in mesothelioma patients who have undergone pleurectomy or extrapleural pneumonectomy and adjuvant intraoperative photodynamic therapy

Patients treated on a Phase-I clinical trial of photodynamic therapy (PDT) developed a systemic capillary leak syndrome that constituted the dose-limiting toxicity. We examined serum samples from patients treated at the maximally tolerated dose level for evidence of a systemic, cytokine-mediated inflammatory response. Patients underwent pleurectomy or extrapleural pneumonectomy (EPP) followed by intraoperative PDT of the thorax using Foscan at a dose of 0.1 mg/kg 6 days before surgery and 652 nm red light at a dose of 10 J/cm2. Levels of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-6, IL-8, IL-10 and IL-12 were assayed before Foscan administration; after anesthetic induction, surgical resection and light delivery; in postoperative recovery and the day after the surgery. Of the analyzed patients, eight underwent a pleurectomy and one an EPP followed by PDT. IFN-gamma, TNF-alpha and IL-12 showed no elevation, but IL-1beta, IL-6, IL-8 and IL-10 levels were elevated after surgery and PDT. IL-1beta showed a statistically significant variation from baseline after surgery and IL-6, after PDT. The results suggest a systemically mediated inflammatory response resulting from thoracic surgery followed by PDT. Further investigation of specific mechanisms is warranted.

Expression of TCR-zeta chain and apoptosis in subpopulations of tumor-associated lymphocytes (TALs) from malignant pleural effusions

Malignant effusions in serous cavities represent suspension of tumors and inflammatory cells and therefore present an attractive model for studying tumor-host interactions. T cell functional ability is linked to proper signal transduction via T cell receptor (TCR-CD3 complex), especially its zeta chain. The latter has been found to be often depressed in malignancy. Aim of this study was to assess alterations of zeta chain expression and its relation to apoptosis of T lymphocytes. T lymphocytes obtained from pleural effusions of 20 cancer patients and 9 patients with nonmalignant effusions serving as a control were studied. The analysis was performed using flow cytometry combining CD3, CD 4, CD8, CD 16/56, TCR-zeta and TUNEL reaction. In the control group, T lymphocytes obtained from pure lymphocyte effusions had constantly high level of zeta chain while those from malignant pleural effusions had a decreased zeta chain expression. Lymphocytes with low zeta chain expression were the main subpopulation of T cells undergoing apoptosis.

Serum anti-p53 autoantibodies in pleural malignant mesothelioma, lung cancer and non-neoplastic lung diseases

Alterations of the p53 gene may lead to the production of detectable autoantibodies (p53-Abs) in cancer patients. In order to evaluate the association of p53-Abs with pleuropulmonary diseases, four groups of subjects were analyzed by ELISA for serum p53-Abs, in the framework of a molecular epidemiologic study. Two of 30 pleural malignant mesothelioma patients (MM; 6.7%) and 8/48 lung cancer patients (LC; 16.7%) were seropositive, while all 51 healthy controls (HC) were negative. Two of 55 (3.6%) at-risk controls (RC) with non-malignant respiratory diseases were positive and were not subsequently diagnosed any cancer. The difference was statistically significant between LC and RC or HC (P = 0.01), but not between MM and any other group. No correlation was found with age, sex, cancer stage or histology, cigarette smoking or occupational exposure. A longer survival (not significant) was shown in seropositive LC but not in MM. p53 expression in tumor tissue was also evaluated in a subgroup of MM. In conclusion, the presence of detectable p53-Abs in serum was associated in a statistically significant proportion of cases with LC but only occasionally with MM. The longer survival among positive LC patients and the presence of two seropositive among patients with non-neoplastic respiratory diseases should be further investigated.

Injection of human primary effusion lymphoma cells or associated macrophages into severe combined immunodeficient mice causes murine lymphomas

The pathogenesis of immunodeficiency-associated lymphoma is poorly understood. During the past several years, numerous lines of evidence implicating a multistep process of malignant transformation, also known as sequential pathogenesis, have emerged. Tumor-associated macrophage production of specific lymphostimulatory products has been demonstrated and hypothesized to be central to this process. While attempting to establish primary effusion lymphoma in severe combined immunodeficient (SCID) mice, we discovered a potential model of murine lymphomagenesis consistent with the sequential pathogenesis model. This pathogenesis-based model of lymphoma could significantly impact the current thinking about posttransplantation and other immunodeficiency-related lymphoproliferative disorders. Human primary effusion lymphoma-derived CD14+ cell-injected SCID mice developed aggressive murine large cell lymphomas. Tumor cell preparations containing CD14 cells or isolated CD14 cells induced lymphoma/lymphoproliferative diseases in 74% (20 of 27) of injected SCID mice. No tumors were induced by tumor-associated CD3 cells (0 of 4), normal human macrophages (0 of 13), or a murine macrophage cell line (0 of 10). Human macrophages were detected in tumor-bearing animals up to 6 months postinjection in association with the murine T-cell tumors but were not detected in controls or unaffected animals. These observations are consistent with the macrophage-initiated sequential pathogenesis model of disease (M. S. McGrath et al., Acquir. Immune Defic. Syndr., 8: 379-385, 1995; M. S. McGrath et al., Infectious Causes of Cancer: Targets for Intervention, pp. 231-242, Totowa, NJ: Humana Press, 2000).

Soluble HLA class I molecules in malignant pleural and peritoneal effusions and its possible role on NK and LAK cytotoxicity

PURPOSE

To examine the amount of sHLA-I in malignant pleural and peritoneal effusions and its possible role in natural immune defense.

METHODS

Three groups of patients (75 patients with malignancy, 21 with infection, and 27 with other diseases) were studied for sHLA-I value using an ELISA method. Cytolytic activity of freshly isolated pleural and peritoneal effusion-associated lymphoid (EAL) cells from 14 of cases with malignancy were examined and compared to that of ten non-cancerous patients. EAL cells were co-cultured with the autologous cell-free effusions immediately after collection and 3 days after incubation with IL-2.

RESULTS

The mean value of sHLA-I in effusions was 1.01+/-1.36 micro g/ml, 0.97+/-1.20 micro g/ml, and 0.49+/-0.45 micro g/ml, respectively. Despite higher mean sHLA-I levels in malignant and infected patients, no significant difference between these groups was observed ( P >0.05). Generally, the amount of sHLA-I in peritoneal effusions was higher than that for pleural effusions, but the difference was not significant. There were also no statistical differences in the sHLA-I levels between sub-groups of patients with malignancy. EAL cells' killing activity in malignant and infected effusions was 68.15+/-11.73 and 78.28+/-14.41, respectively ( P=0.08). No correlation between sHLA-I level and NK activity of EAL cells from the patients was found. Almost all malignant cases after exposure to cell-free effusions displayed an increase in NK activity (from 68.66+/-11.13 to 74.2+/-12.39, P=0.042) and a decrease in LAK activity (74.5+/-18.30 vs 67.72+/-16.46, P=0.040). Whereas, the same experiment performed for non-malignant effusions showed a decrease in both NK activity and LAK activity. Changes in NK and LAK activity were not correlated with the amount of sHLA-I in the effusions.

CONCLUSION

The presence of sHLA-I, particularly in malignant effusions, suggests a role for these molecules in tumor immunity in the peritoneal or plural environment; however, at least with these group of patients, sHLA-I appears not to be a unique determining factor on EAL cells' killing activity.

Additive effect of Interleukin-12 and Interleukin-18 on the T-helper cell pathway of malignant pleural effusion

Interleukin-18 (IL-18) is a novel cytokine with interferon-gamma (IFN-gamma)-inducing activity, thus favoring the T-helper type 1 (Th-1) pathway. The present study attempts to define the role of IL-18 on the functions of lymphocytes isolated from malignant pleural effusions (EAL, effusion-associated lymphocytes). EAL from 10 patients with malignant pleural effusion were incubated with IL-2, IL-12, or IL-18 with/without a alpha CD3 antibody. ELISA, proliferation, and cytotoxicity assays were performed. IL-18 alone was found to have no significant effect on EAL in terms of cytokine production, lymphocyte proliferation, or cytotoxicity against tumor targets. IL-18 also had no significant additive or synergistic effect on IL-2, IL-12, or alpha CD3 co-cultured EAL. However, when IL-18 was used with IL-12, the highest IFN-gamma/IL-10 ratio was derived, suggesting that these two cytokines had an additive effect in leading EAL from the Th-2 to the Th-1 pathway. Furthermore, 1 of 5 patients' EAL had its strongest cytolytic activity against an autologous tumor when the EAL was cultured with IL-2 plus IL-18, as compared with the other 4 patients whose EAL cytolytic activity against autologous tumor was highest when using IL-2 plus alpha CD3. These findings suggest that IL-18 alone did not have a significant effect on EAL, and that IL-18 did not enhance alpha CD3's activity on EAL. However, its additive effect with IL-12 in the Th-1 pathway and with IL-2 in its cytolytic activity against an autologous tumor deserve further studies.

Malignant effusions and immunogenic tumour-derived exosomes

BACKGROUND

Exosomes derived from tumours are small vesicles released in vitro by tumour cell lines in culture supernatants. To assess the role of these exosomes in vivo, we examined malignant effusions for their presence. We also investigated whether these exosomes could induce production of tumour-specific T cells when pulsed with dendritic cells.

METHODS

We isolated exosomes by ultracentrifugation on sucrose and D(2)O gradients of 11 malignant effusions. We characterised exosomes with Western blot analyses, immunoelectron microscopy, and in-vitro stimulations of autologous T lymphocytes.

FINDINGS

Malignant effusions accumulate high numbers of membrane vesicles that have a mean diameter of 80 nm (SD 30). These vesicles have antigen-presenting molecules (MHC class-I heat-shock proteins), tetraspanins (CD81), and tumour antigens (Her2/Neu, Mart1, TRP, gp100). These criteria, including their morphological characteristics, indicate the similarities between these vesicles and exosomes. Exosomes from patients with melanoma deliver Mart1 tumour antigens to dendritic cells derived from monocytes (MD-DCs) for cross presentation to clones of cytotoxic T lymphocytes specific to Mart1. In seven of nine patients with cancer, lymphocytes specific to the tumour could be efficiently expanded from peripheral blood cells by pulsing autologous MD-DCs with autologous ascitis exosomes. In one patient tested, we successfully expanded a restricted T-cell repertoire, which could not be recovered carcinomatosis nodules.

INTERPRETATION

Exosomes derived from tumours accumulate in ascites from patients with cancer. Ascitis exosomes are a natural and new source of tumour-rejection antigens, opening up new avenues for immunisation against cancers.