Interleukin-13 and interleukin-13 receptor in Hodgkin's disease: possible autocrine mechanism and involvement in fibrosis

The Tumor Microenvironment in Classic Hodgkin's Lymphoma in Responder and No-Responder Patients to First Line ABVD Therapy

Although classical Hodgkin lymphoma (CHL) is typically curable, 15-25% of individuals eventually experience a relapse and pass away from their disease. In CHL, the cellular microenvironment is constituted by few percent of H/RS (Hodgkin/Reed-Sternberg) tumor cells surrounded from a heterogeneous infiltration of inflammatory cells. The interplay of H/RS cells with other immune cells in the microenvironment may provide novel strategies for targeted immunotherapies. In this paper we analyzed the microenvironment content in CHL patients with responsive disease (RESP) and patients with relapsed/refractory disease to treatment (REL). Our results indicate the increase of CD68⁺ and CD163⁺ macrophages, the increase of PDL-1⁺ cells and of CD34⁺ microvessels in REL patients respective to RESP patients. In contrast we also found the decrease of CD3⁺ and of CD8⁺ lymphocytes in REL patients respective to RESP patients. Finally, in REL patients our results show the positive correlation between CD68⁺ macrophages and PDL-1⁺ cells as well as a negative correlation between CD163⁺ and CD3⁺.

The Medium Obtained from the Culture of Hodgkin Lymphoma Cells Affects the Biophysical Characteristics of a Fibroblast Cell Model

The neoplastic Hodgkin-Reed-Sternberg (HRS) cells in Hodgkin lymphoma (HL) represent only 1-10% of cells and are surrounded by an inflammatory microenvironment. The HL cytokine network is a key point for the proliferation of HRS cells and for the maintenance of an advantageous microenvironment for HRS survival. In the tumor microenvironment (TME), the fibroblasts are involved in crosstalk with HRS cells. The aim of this work was to study the effect of lymphoma cell conditioned medium on a fibroblast cell population and evaluate modifications of cell morphology and proliferation. Hodgkin lymphoma-derived medium was used to obtain a population of "conditioned" fibroblasts (WS-1 COND). Differences in biophysical parameters were detected by the innovative device Celector^®. Fibroblast-HL cells interactions were reproduced in 3D co-culture spheroids. WS-1 COND showed a different cellular morphology with an enlarged cytoplasm and enhanced metabolism. Area and diameter cell values obtained by Celector^® measurement were increased. Co-culture spheroids created with WS-1 COND showed a tighter aggregation than those with non-conditioned WS-1. The presence of soluble factors derived from HRS cells in the conditioned medium was adequate for the proliferation of fibroblasts and conditioned fibroblasts in a 3D HL model allowed to develop a representative model of the in vivo TME.

Inflammatory microenvironment in classical Hodgkin’s lymphoma with special stress on mast cells

Classical Hodgkin’s lymphoma (CHL) accounts for 10% of all lymphomas. Nodular sclerosis and mixed cellularity accounts for nearly 80% of all CHL cases. The number of mast cells in CHL correlates with poor prognosis, is significantly higher in nodular sclerosis than in other CHL subtypes, and an association between the degree of angiogenesis and the number of intratumoral mast cells has been demonstrated in CHL. Even with the best available treatment, a significant percentage of CHL patients progress or relapse after first-line therapy. 50% of patients with disease relapse achieve subsequent long-term disease control with salvage therapies. In this context, new potential therapeutic opportunities are required, and mast cells may be regarded as a new target for adjuvant treatment of CHL through the inhibition of angiogenesis and tissue remodeling and allowing the secretion of cytotoxic cytokines.

Immune-Proteome Profiling in Classical Hodgkin Lymphoma Tumor Diagnostic Tissue

In classical Hodgkin Lymphoma (cHL), immunoediting via protein signaling is key to evading tumor surveillance. We aimed to identify immune-related proteins that distinguish diagnostic cHL tissues (=diagnostic tumor lysates, n = 27) from control tissues (reactive lymph node lysates, n = 30). Further, we correlated our findings with the proteome plasma profile between cHL patients (n = 26) and healthy controls (n = 27). We used the proximity extension assay (PEA) with the OlinkTM multiplex Immuno-Oncology panel, consisting of 92 proteins. Univariate, multivariate-adjusted analysis and Benjamini–Hochberg’s false discovery testing (=Padj) were performed to detect significant discrepancies. Proteins distinguishing cHL cases from controls were more numerous in plasma (30 proteins) than tissue (17 proteins), all Padj < 0.05. Eight of the identified proteins in cHL tissue (PD-L1, IL-6, CCL17, CCL3, IL-13, MMP12, TNFRS4, and LAG3) were elevated in both cHL tissues and cHL plasma compared with control samples. Six proteins distinguishing cHL tissues from controls tissues were significantly correlated to PD-L1 expression in cHL tissue (IL-6, MCP-2, CCL3, CCL4, GZMB, and IFN-gamma, all p ≤0.05). In conclusion, this study introduces a distinguishing proteomic profile in cHL tissue and potential immune-related markers of pathophysiological relevance.

The circuitry of the tumor microenvironment in adult and pediatric Hodgkin lymphoma: cellular composition, cytokine profile, EBV, and exosomes

BACKGROUND

Classical Hodgkin lymphoma (cHL) is a unique lymphoid malignancy with a tumor microenvironment (TME) consisting of a small number of neoplastic-Hodgkin and Reed-Sternberg (H-RS) cells (<1%), surrounded by a large number of nonneoplastic infiltrating immune cells (>90%). The TME of cHL critically depends on immune cells to support tumor growth as H-RS cells cannot survive and proliferate in isolation.

RECENT FINDINGS

Programmed cell death protein 1 (PD-1) ligand expressed on H-RS cells inhibits the clearance of tumor by causing T-cell exhaustion. Nivolumab and pembrolizumab, PD-1 inhibitors, have been proven to be effective in treating adult and pediatric patients with R/R cHL. Tumor-associated macrophages (TAMs) are a central component of TME and are known to cause poor prognosis in adult HL. However, the prognostic impact of CD68+ TAMs in pediatric HL remains ambiguous. EBV modulates the tumor milieu of HL and plays a strategic role in immune escape by enrichment of the TME with T_reg cells and associated immunosuppressive cytokines in adult HL. In contrast, EBV+ pediatric patients have increased infiltration of CD8⁺ T-cells and show a better therapeutic response suggesting viral-related TME is distinct in childhood HL. The role of CASP3 in apoptosis of H-RS cells and its correlation with response prediction in adult and pediatric HL suggest it may serve as a potential biomarker. In cHL, CD30, EBV, and NF-κB signaling employ exosomes for cell-cell communication that triggers the migration capacity of fibroblasts, stimulate to produce proinflammatory cytokines, and help to create a tumor-supportive microenvironment.

CONCLUSION

The cHL microenvironment is distinct in adult and pediatric HL. Future studies are required to understand the role of interplay between H-RS cells and EBV-associated microenvironment and their clinical outcome. They may present novel therapeutic targets for the development of antilymphoma therapy.

[Microenvironment in classical Hodgkin lymphoma]

Classical Hodgkin lymphoma (cHL) is histologically characterized by a quantitatively dominating immune cell infiltrate. Its composition differs depending on the histological subtype and EBV (Epstein-Barr-Virus) status. Current pathogenic concepts postulate that the malignant cells, the so-called Hodgkin and Reed-Sternberg (HRS) cells, act as master recruiters, thereby actively shaping the microenvironment to support their proliferation and outgrowth. This view on the pathogenesis of cHL is further solidified by genetic studies, which have identified important mechanisms by which the HRS cells are enabled to escape immune surveillance. Besides an insufficient antigen presentation mediated by mutations and structural chromosomal changes in key components or regulators of major histocompatibility class I and II molecules, copy number gains of the 9p24.1 genomic locus encompassing JAK2 and the ligands of the programmed cell death protein 1 (PD-1), PD-L1 and PD-L2, play an important role in the pathogenesis of this disease as the engagement of those ligands with their cognate receptor leads to suppression of the immune response. Of importance, the reversibility of this inhibitory receptor-ligand interaction is key to the clinical success that checkpoint inhibitors had and continue to have in cHL patients, especially in the relapse setting. In addition, comprehensive assessment of microenvironment composition, integration with results from genetic studies, and correlation with clinical outcomes have led to the development of prognostic models, which may assist in an improved risk stratification, informed selection of treatment regimens, and therefore better outcomes.

Fibroblasts in Nodular Sclerosing Classical Hodgkin Lymphoma Are Defined by a Specific Phenotype and Protect Tumor Cells from Brentuximab-Vedotin Induced Injury

Classical Hodgkin lymphoma (cHL) is one of the most common malignant lymphomas in Western Europe. The nodular sclerosing subtype of cHL (NS cHL) is characterized by a proliferation of fibroblasts in the tumor microenvironment, leading to fibrotic bands surrounding the lymphoma infiltrate. Several studies have described a crosstalk between the tumour cells of cHL, the Hodgkin- and Reed-Sternberg (HRS) cells, and cancer-associated fibroblasts. However, to date a deep molecular characterization of these fibroblasts is lacking. Thus, the aim of the present study is a comprehensive characterization of these fibroblasts. Gene expression profiling and methylation profiles of fibroblasts isolated from primary lymph node suspensions revealed persistent differences between fibroblasts obtained from NS cHL and lymphadenitis. NS cHL derived fibroblasts exhibit a myofibroblastic phenotype characterized by myocardin (MYOCD) expression. Moreover, TIMP3, an inhibitor of matrix metalloproteinases, was strongly upregulated in NS cHL fibroblasts, likely contributing to the accumulation of collagen in sclerotic bands of NS cHL. As previously shown for other types of cancer-associated fibroblasts, treatment by luteolin could reverse this fibroblast phenotype and decrease TIMP3 secretion. NS cHL fibroblasts showed enhanced proliferation when they were exposed to soluble factors released from HRS cells. For HRS cells, soluble factors from fibroblasts were not sufficient to protect them from Brentuximab-Vedotin induced cell death. However, HRS cells adherent to fibroblasts were protected from Brentuximab-Vedotin induced injury. In summary, we confirm the importance of fibroblasts for HRS cell survival and identify TIMP3 which probably contributes as a major factor to the typical fibrosis observed in NS cHL.

3D analysis of morphological alterations of the fibroblastic reticular cells in reactive and neoplastic human lymph nodes

Histopathological methods based on 2 μm thin sections are routinely used in pathological anatomical diagnosis. Many medical disciplines already rely on a 3D representation, regarding visualization and imaging techniques. Pathology in particular uses different tissue visualizations to make the final diagnosis. Thereby, a standard 2D histological section only represents a flat snapshot of a three-dimensional complex cell system. Despite that, 3D cell analysis is not yet standardly used in clinical routine. This work used 3D analysis systems to investigate the morphological alterations of the fibroblastic reticular cell network inside human lymph nodes during neoplastic transformation and evaluates the added value of 3D visualizations in tissue interpretation. We investigated the surface and volume quotient, cell cross-linking and percentage cell volume of the fibroblastic reticular cell (FRC) network inside Lymphadenopathy (follicular hyperplasia) (LAD), Follicular Lymphoma Grade 1 (FL1), Nodular Sclerosis classical Hodgkin Lymphoma (NScHL) and Angioimmunoblastic T-Cell Lymphoma (AITL). We found that the average quotient of LAD and FL1 differed from those of NScHL and AITL, indicating that the surface and volume quotient changes in the course of neoplastic transformation. This is probably due to an increased network convolution, while the total cell volume remains the same at about 2%. In conclusion, this paper describes the tumor-related morphological changes of the FRC network, which would have been difficult to achieve without the use of 3D analysis systems.

Paraneoplastic immunoglobulin A nephropathy and associated focal segmental glomerulosclerosis in asymptomatic low volume B-cell lymphoma - a case report

Background

Paraneoplastic glomerulonephritis is rare in haematological malignancies and tends to manifest as minimal change disease, membranous glomerulonephritis or membranoproliferative glomerulonephritis. We present the first report of immunoglobulin A nephropathy and associated focal segmental glomerulosclerosis in a patient with asymptomatic low grade B-cell lymphoma.

Case presentation

A 53 year old gentleman presented with nephrotic range proteinuria (urine protein creatinine ratio of 662 mg/mmol) on a background of type 2 diabetes mellitus (glycosylated haemoglobin: < 6%), hypertension, obesity (body mass index: 47.6 kg/m²) and degenerative spine disease. Bone marrow biopsy diagnosed a low grade B-cell lymphoma and renal biopsy was consistent with immunoglobulin A nephropathy. Lymphoma treatment with six cycles of cyclophosphamide/ rituximab/ prednisolone led to normalisation of urinary protein excretion (urine protein creatinine ratio: 14 mg/mmol at 26 months post-chemotherapy).

Conclusion

Paraneoplastic immunoglobulin A nephropathy can occur with a broad range of haematological malignancies regardless of stage. This case illustrates the importance of meticulous haematological system work-up for patients presenting with immunoglobulin A nephropathy. Recognition of paraneoplastic immunoglobulin A nephropathy and early diagnosis of associated malignancy can be life-saving.

Fibrosis in low-grade follicular lymphoma - a link to the TH2 immune reaction

There is evidence from studies on fibrotic diseases that a TH2 polarized immune response, characterized by the production of cytokines like IL-4, IL-5, and IL-13 is important for fibrosis development. Data concerning the role of TH2 polarized immune response for fibrogenesis in lymphomas are scarce. Using immunohistochemistry, we investigated paraffin embedded tissue specimens of 58 follicular lymphomas (FL) grade 1/2 with and without fibrosis. In FL with fibrosis, we detected more interfollicular GATA-3 positive lymphocytes and a shift towards a TH2 immune response. In areas of fibrosis, which were enriched with myofibroblasts, we observed a polarization of macrophages towards a M2 phenotype with expression of CD163. Our results hold some evidence that a polarization of the adaptive immune system towards a TH2 immune response in the tumor microenvironment is associated with increased fibrosis, which may indicate its functional relevance for either development or maintenance of fibrosis in FL.

Role of mast cells in fibrosis of classical Hodgkin lymphoma

The underlying mechanism of fibrosis in classical Hodgkin lymphoma (CHL) remains uncertain. This study aimed to investigate the association of fibrosis in the lymph nodes of patients with CHL through histological examination of the expression of cytokines associated with fibrosis and mast cell proliferation. Additionally, we sought to determine the degree of mast cell infiltration in a nodular sclerosis subtype of CHL (NSCHL) compared with that in non-NSCHL. We analyzed lymph nodes from 22 patients with CHL, of which eight were of the NSCHL and 14 of the non-NSCHL subtype, using immunohistochemical staining of forkhead box P3 (FOXP3), transforming growth factor (TGF)-β, interleukin (IL)-3, IL-13, and stem cell factor (SCF). Mast cells were positive for TGF-β and IL-13, and FOXP3-positive cells were negative for TGF-β. Only the expression of IL-13 in Hodgkin and Reed-Sternberg (HRS) cells was significantly more frequently observed in NSCHL than that in non-NSCHL (P = 0.0028) and was associated with a higher rate of fibrosis (P = 0.0097). The number of mast cells was significantly higher in NSCHL than that in non-NSCHL (P = 0.0001). A significantly positive correlation was observed between the rate of fibrosis and the number of mast cells (correlation coefficient, 0.8524; 95% CI, 0.6725-0.9372) (P <0.0001). The number of mast cells was significantly higher in the group with IL-13-positive HRS cells than that in the group with IL-13-negative HRS cells (P = 0.0157). Based on these findings, we hypothesize that IL-13 production by HRS cells may lead to fibrosis, and furthermore, promote mast cell proliferation and infiltration. This in turn might further produce the fibrotic cytokines IL-13 and TGF-β, resulting in fibrosis typical of NSCHL.

Microenvironment-related biomarkers and novel targets in classical Hodgkin's lymphoma

Classical Hodgkin's lymphoma accounts for approximately 10% of all malignant lymphomas. Although most patients can be cured with modern treatment strategies, approximately 25% of them experience either primary or secondary chemorefractoriness or disease relapse, thus requiring novel treatments. Increasing preclinical and clinical evidences have demonstrated the role of microenvironment in the molecular pathogenesis of classical Hodgkin's lymphoma and elucidated the complex cross-talk between the malignant Hodgkin Reed–Sternberg cells and the nonmalignant, reactive cells of the microenvironment, strongly supporting novel therapeutic approaches aimed at targeting Hodgkin's Reed–Sternberg cells along with reactive cells in order to overcome chemorefractoriness. In the near future, these novel therapies will also be tested in chemosensitive patients to reduce long-term toxicities of chemo-radiotherapy.

Control of the inflammatory response mechanisms mediated by natural and induced regulatory T-cells in HCV-, HTLV-1-, and EBV-associated cancers

Virus infections are involved in chronic inflammation and, in some cases, cancer development. Although a viral infection activates the immune system's response that eradicates the pathogen mainly through inflammatory mechanisms, it is now recognized that this inflammatory condition is also favorable to the development of tumors. Indeed, it is well described that viruses, such as hepatitis C virus (HCV), Epstein Barr virus (EBV), human papillomavirus (HPV) or human T-cell lymphotropic virus type-1 (HTLV-1), are important risk factors for tumor malignancies. The inflammatory response is a fundamental immune mechanism which involves several molecular and cellular components consisting of cytokines and chemokines that are released by various proinflammatory cells. In parallel to this process, some endogenous recruited components release anti-inflammatory mediators to restore homeostasis. The development of tools and strategies using viruses to hijack the immune response is mostly linked to the presence of regulatory T-cells (Treg) that can inhibit inflammation and antiviral responses of other effector cells. In this review, we will focus on current understanding of the role of natural and induced Treg in the control and the resolution of inflammatory response in HCV-, HTLV-1-, and EBV-associated cancers.

Targeting and killing of glioblastoma with activated T cells armed with bispecific antibodies

Background

Since most glioblastomas express both wild-type EGFR and EGFRvIII as well as HER2/neu, they are excellent targets for activated T cells (ATC) armed with bispecific antibodies (BiAbs) that target EGFR and HER2.

Methods

ATC were generated from PBMC activated for 14 days with anti-CD3 monoclonal antibody in the presence of interleukin-2 and armed with chemically heteroconjugated anti-CD3×anti-HER2/neu (HER2Bi) and/or anti-CD3×anti-EGFR (EGFRBi). HER2Bi- and/or EGFRBi-armed ATC were examined for in vitro cytotoxicity using MTT and ⁵¹Cr-release assays against malignant glioma lines (U87MG, U118MG, and U251MG) and primary glioblastoma lines.

Results

EGFRBi-armed ATC killed up to 85% of U87, U118, and U251 targets at effector:target ratios (E:T) ranging from 1:1 to 25:1. Engagement of tumor by EGFRBi-armed ATC induced Th1 and Th2 cytokine secretion by armed ATC. HER2Bi-armed ATC exhibited comparable cytotoxicity against U118 and U251, but did not kill HER2-negative U87 cells. HER2Bi- or EGFRBi-armed ATC exhibited 50—80% cytotoxicity against four primary glioblastoma lines as well as a temozolomide (TMZ)-resistant variant of U251. Both CD133– and CD133+ subpopulations were killed by armed ATC. Targeting both HER2Bi and EGFRBi simultaneously showed enhanced efficacy than arming with a single BiAb. Armed ATC maintained effectiveness after irradiation and in the presence of TMZ at a therapeutic concentration and were capable of killing multiple targets.

Conclusion

High-grade gliomas are suitable for specific targeting by armed ATC. These data, together with additional animal studies, may provide the preclinical support for the use of armed ATC as a valuable addition to current treatment regimens.

Alterations of serum biomarkers associated with lung ventilation function impairment in coal workers: a cross-sectional study

BACKGROUND

Previous studies have demonstrated that alterations in certain circulating biomarkers may be correlated with Coal workers' pneumoconiosis (CWP). This study investigated the relationship between changes of serum biomarkers and pulmonary function during the development of CWP.

METHODS

Lung function parameters and specific serum indices were measured in 69 non-smoking coal workers, including 34 miners with CWP, 24 asymptomatic miners and 11 miners with minimal symptoms. The associations between changes in pulmonary function and serum indices were tested with Pearson's correlation coefficients. Multivariable analysis was used to estimate the predictive power of potential determinant variables for lung function.

RESULTS

Compared to healthy miners, lung function (FVC, FEV1, FEF50, FEF75, FEF25-75 % of predicted values) was decreased in miners with CWP (p < 0.05). Increased serum matrix metalloproteinase-9 (MMP-9) was associated with decreased FVC% of predicted values in the asymptomatic miners (r = -0.503, p = 0.014).

CONCLUSIONS

In coal mine workers, alterations of lung function parameters are associated with the development of CWP and with changes in circulating MMP-9, TIMP-9, IL-13 and IL-18R. These serum biomarkers may likely reflect the pathogenesis and progression of CWP in coal workers, and may provide for the importance of serum indicators in the early diagnosis of lung function injury in coal miners.

Serum levels of interleukins 6, 10, and 13 before and after treatment of classic Hodgkin lymphoma

CONTEXT

Interleukins (ILs) 6, 10, and 13 seem to be important in the pathogenesis of Hodgkin lymphoma (HL), but there is insufficient data on the serum levels of these cytokines in patients with HL.

OBJECTIVES

To evaluate serum levels of IL-6, IL-10, and IL-13 before and after HL treatment and to determine their potential association with clinical and laboratory parameters.

DESIGN

Serum IL-6, IL-10, and IL-13 levels were quantified in the serum of 27 patients with HL by enzyme-linked immunosorbent assay. Results were evaluated against clinical and laboratory parameters, response to treatment, and presence of infection by the Epstein-Barr virus. As a control group, serum samples from 26 healthy blood donors were evaluated the same way.

RESULTS

Pretreatment serum levels of IL-6 and IL-10 were significantly higher in patients with HL (P < .001), and a significant decrease was observed after treatment (P < .001). Serum IL-13 was undetectable in both patient and control groups. Serum IL-6 was higher in patients with abdominal involvement (P  =  .02), hepatomegaly (P  =  .03), B symptoms (P  =  .02), and anemia (P  =  .02). Serum IL-10 levels were higher in patients with hypoalbuminemia (P  =  .04). No association with EBV status was observed. Lymphocytopenia and B symptoms were accurate predictors of IL-6 serum levels before treatment, and higher pretreatment levels of IL-6 were observed in patients with treatment failure (P  =  .03).

CONCLUSIONS

Serum levels of IL-6 and IL-10 were frequently elevated in patients with HL and decreased substantially after conventional chemotherapy. The association of elevated IL-6 and IL-10 levels in serum with some clinical and laboratory features suggests those ILs may be useful biomarkers for monitoring the HL disease and its response to chemotherapy.

Molecular Pathogenesis of Hodgkin's Lymphoma: Increasing Evidence of the Importance of the Microenvironment

Hodgkin's lymphoma (HL) represents the most common subtype of malignant lymphoma in young people in the Western world. Most patients can be cured with modern treatment strategies, although approximately 20% will die after relapse or progressive disease. The histologic hallmark of the disease is the presence of the characteristic Hodgkin Reed-Sternberg (HRS) cells in classical HL and so-called lymphocyte-predominant (LP) cells in nodular lymphocyte-predominant HL. HL is unique among all cancers because malignant cells are greatly outnumbered by reactive cells in the tumor microenvironment and make up only approximately 1% of the tumor. Expression of a variety of cytokines and chemokines by the HRS and LP cells is believed to be the driving force for an abnormal immune response, perpetuated by additional factors secreted by reactive cells in the microenvironment that help maintain the inflammatory milieu. The malignant HRS and LP cells manipulate the microenvironment, permitting them to develop their malignant phenotype fully and evade host immune attack. Gene expression signatures derived from non-neoplastic cells correlate well with response to initial and subsequent therapies, reflecting their functional relevance. Recent biomarker studies have added texture to clinical outcome predictors, and their incorporation into prognostic models may improve our understanding of the biologic correlates of treatment failure. Moreover, recent preclinical and clinical studies have demonstrated that the tumor microenvironment represents a promising therapeutic target, raising hope that novel treatment strategies focused on the interface between malignant and reactive cells will soon emerge.

Pathogenesis, diagnosis and management of paraneoplastic glomerulonephritis

Paraneoplastic glomerulonephritis is a rare complication of malignancy that is frequently mistaken for idiopathic glomerulonephritis. Failure to recognize paraneoplastic glomerulonephritis can subject patients to ineffective and potentially harmful therapy. The pathology of paraneoplastic glomerulonephritis varies between different types of malignancies. This Review discusses the association of glomerulonephritis with both solid tumors and hematological malignancies. The pathogenetic mechanisms of many glomerular lesions seem to relate to altered immune responses in the presence of a malignancy. Studies in the Buffalo/Mna rat model of spontaneous thymoma and nephrotic syndrome indicate that polarization of the immune response toward a T-helper-2 (T(H)2) profile has an important role in the development of thymoma-associated glomerular lesions. Furthermore, overexpression of the T(H)2 cytokine interleukin 13 in rats induces minimal change disease. Such findings from experimental studies might facilitate the identification of biomarkers that can distinguish paraneoplastic glomerulonephritis from idiopathic and other secondary glomerulonephritides. This Review describes potential pathogenetic mechanisms for paraneoplastic glomerulonephritides associated with different malignancies and highlights the need for a multidisciplinary approach to the management of patients with paraneoplastic glomerulonephritis.

Mechanisms of aberrant GATA3 expression in classical Hodgkin lymphoma and its consequences for the cytokine profile of Hodgkin and Reed/Sternberg cells

The transcription factor network in Hodgkin lymphoma (HL) represents a unique composition of proteins found in no other hematopoietic cell. Among these factors, an aberrant expression of the T-cell transcription factor GATA3 is observed in B cell–derived Hodgkin and Reed/Sternberg (HRS) tumor cells. Herein, we elucidate the regulation and function of this factor in HL. We demonstrate binding of NFκB and Notch-1, 2 factors with deregulated activity in HL to GATA3 promoter elements. Interference with NFκB and Notch-1 activity led to decreased GATA3 expression, indicating a dependency of deregulated GATA3 expression on these transcription factors. Down-regulation of GATA3 in HL cell lines demonstrated its role in the regulation of IL-5, IL-13, STAT4, and other genes. A correlation between GATA3 and IL-13 expression was confirmed for HRS cells in HL tissues. Thus, GATA3 shapes the cytokine expression and signaling that is typical of HL. Conclusively, aberrant GATA3 expression in HRS cells is stimulated by the deregulated constitutive activity of NFκB and Notch-1, indicating a complex network of deregulated transcription factors in these cells. GATA3 activity significantly contributes to the typical cytokine secretion of and signaling in HRS cells, which presumably plays an essential role in HL pathogenesis.

The cytokine/chemokine pattern in the bone marrow environment of multiple myeloma patients

OBJECTIVE

The interaction of multiple myeloma (MM) with its bone marrow (BM) microenvironment is important for the homing pattern, survival, and proliferation of malignant plasma cells. We aimed at answering the question which cytokines, chemokines, and growth factors are typically found in the BM of untreated MM patients as well as in MM patients after allogeneic stem cell transplantation (alloSCT).

MATERIALS AND METHODS

We determined the concentrations of 34 cytokines/chemokines in the supernatants of 10 myeloma cell lines, as well as in the plasma derived from BM and peripheral blood samples of 10 newly diagnosed MM patients, 20 MM patients who had received allogeneic stem cell transplantation (alloSCT), and 20 healthy donors.

RESULTS

Besides cytokines/chemokines known to be secreted by myeloma cell lines, such as interleukin-1 receptor antagonist (IL-1RA), IL-8, monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein (MIP)-1α, MIP-1β, and MIP-3α, we also detected significant levels of epidermal growth factor (EGF), hepatocyte growth factor (HGF), IL2R, IL-12p40/p70, IL-22, interferon-γ (IFN-γ)-inducible protein 10 (IP-10), monokine induced by IFN-γ (MIG), and regulated on activation normally T-cell expressed and secreted (RANTES) in culture supernatants. The BM environment in MM patients evidenced elevated concentrations of HGF, IL-2R, IL-16, EGF, IL-1RA, IP-10, MCP-1, and monokine induced by IFN-γ. Additionally, in the BM of MM patients post alloSCT, we found selectively elevated concentration of IL-4, IL-6, IL-8, IL-12p40/p70, and eotaxin. Eotaxin levels were particularly high in patients with chronic graft-vs-host disease.

CONCLUSIONS

Our study demonstrates characteristic cytokine/chemokine patterns in the BM environment of MM patients before and after alloSCT. Certain factors, such as MIP-1α, MCP-1, HGF, IL-16, IP-10, and eotaxin, might not only be developed into diagnostic instruments and/or predictive biomarkers, but are also potential targets for future myeloma- or graft-vs-host disease-specific therapies.

Elevated IL-13Ralpha2 in intestinal epithelial cells from ulcerative colitis or colorectal cancer initiates MAPK pathway

BACKGROUND

Chronic inflammation in ulcerative colitis (UC) is a sizeable risk factor for colorectal cancer (CRC). Interleukin-13 (IL-13) is elevated in the UC mucosa and may induce dysregulated signaling in neighboring intestinal epithelial cells (IECs) and thus function as a tumorogenic cytokine.

METHODS

Expression of IL-13 receptor chains on IECs obtained from control or chronically inflamed mucosa and colonic tumors was quantified by flow cytometry and immunoblot. IL-13Ralpha1 and IL-13Ralpha2 expression was significantly increased on IEC from UC and CRC patients compared to control and Crohn's disease (CD) subjects. Purified IEC from these subjects and cell lines expressing varying ratios of IL-13Ralpha1 and IL-13Ralpha2 chains were stimulated with IL-13 in vitro to investigate by immunoblot the activation of the signal transducer and activator of transcription 6 (STAT6) and mitogen activated protein kinase (MAPK) signaling pathways.

RESULTS

Despite similarly elevated receptor expression in UC and CRC, IL-13 does not activate the STAT6 or MAPK pathways in UC, while in colonic tumors only the STAT6 pathway is activated. Using neutralizing antibodies and cell lines expressing a range of surface densities for IL-13Ralpha1 and IL-3Ralpha2, we demonstrate that IL-13Ralpha2 serves a dual role, initiating MAPK signaling at low concentrations and as an inhibitory, decoy receptor at high IL-13Ralpha2 to IL-13Ralpha1 ratios.

CONCLUSIONS

IL-13Ralpha2 is both a decoy receptor and induces MAPK signal transduction, depending on its relative expression and the local concentration of IL-13, which together modulate the balance and intensity of the signaling pathways initiated in UC and CRC.

Hodgkin lymphoma: an update on its biology with new insights into classification

In the past few years, there has been a greater understanding of the spectrum and biology of Hodgkin lymphoma (HL). In standard texts, HL is classified as 2 distinct entities, namely nodular lymphocyte-predominant HL and classical HL (CHL). However, recent evidence suggests that CHL is not a single disease. Although the mixed cellularity and lymphocyte-depleted subtypes might be part of a biologic continuum, the nodular sclerosis subtype has a distinct epidemiology, clinical presentation, and histology. Nodular sclerosis HL might also be related to primary mediastinal B-cell lymphoma and mediastinal gray-zone lymphomas. We present an update on the pathobiology of HL and discuss these biologic and clinical differences in this review.

Interleukin-13 exerts autocrine growth-promoting effects on human pancreatic cancer, and its expression correlates with a propensity for lymph node metastases

BACKGROUND AND AIMS

Interleukin-13 (IL-13) is an anti-inflammatory cytokine produced in cells of hematopoetic origin. It is not known whether pancreatic cancer cells produce IL-13 or whether IL-13 can modulate pancreatic cancer cell growth and influence the frequency of lymph node metastases.

MATERIALS AND METHODS

Cell growth and signaling were analyzed by cell counting, colorimetric proliferation assays, fluorescent-activated cell sorting, and in vitro kinase activity assays. IL-13 expression and secretion were determined by Northern blot analysis and enzyme-linked immunosorbent assay, respectively. Localization of IL-13 and its transmembrane receptor (IL-4R) in primary pancreatic ductal adenocarcinoma (PDAC) was characterized by immunohistochemistry.

RESULTS

IL-13 enhanced the growth of ASPC-1, CAPAN-1, and COLO-357 cells. This was associated with enhanced p44/42 mitogen-activated protein kinase (MAPK) phoshorylation. In contrast to p44/42 MAPK, phosphatidylinositol 3-kinase activity was also induced in IL-13-unresponsive MIA PaCa-2, PANC-1, and T3M4 cells. All cells expressed and secreted IL-13. Neutralizing IL-13 antibodies inhibited the growth of ASPC-1 and CAPAN-1 cells. Immunohistochemical analysis of resected primary ductal adenocarcinoma specimens revealed high levels of IL-13 in 30 of 70 cases and its transmembrane receptor (IL-4R) in 28 of 70 cases, respectively. Fifteen of 16 specimens (94%) exhibiting high IL-13 and IL-4R coexpression had lymph node metastases, while only 30 of the remaining 54 samples (56%) had positive lymph nodes (p = 0.0134).

CONCLUSION

IL-13 can act as an autocrine growth factor in PDAC. Endogenous expression of IL-13 in conjunction with IL-4R in the cancer cells seems to facilitate lymph node metastasis.

Primary mediastinal B-cell lymphoma: treatment and therapeutic targets

Primary mediastinal B-cell lymphoma (PMBCL) is a recognised subtype of diffuse large B-cell lymphoma according to the WHO classification that represents approximately 5% of aggressive lymphomas, and 2% of all cases of lymphomas. It presents with unique clinical, morphologic and immunophenotypic characteristics that define the disease. Retrospective studies have found that PMBCL patients have excellent survival rates with a distinct plateau and a trend to better outcome if treated with dose-intensified chemotherapy with MACOPB or VACOPB. In spite of the multiple molecular data known, generated on the pathogenesis of this tumour, treatment is still essentially based on a combination of chemo and immunotherapy. We take this opportunity for reviewing the recent biologic data provided by gene expression profiling of the tumour, for discussing new potential therapeutic targets.

Regulatory T cells as therapeutic target in Hodgkin's lymphoma

BACKGROUND

The clinical and pathological features of Hodgkin's lymphoma (HL) reflect an abnormal immune response that results from cytokines and chemokines secreted by Hodgkin/Reed-Sternberg (H/R-S) cells and/or the surrounding tissue.

OBJECTIVE

Increasing evidence indicates that H/R-S cells recruit and/or induce regulatory T (Treg) cells that contribute to an ineffective immune clearance of the malignant cell types and may also impair effects of adaptive cellular immunotherapy applied in HL.

METHODS

In this review we highlight advances in the understanding of immune regulation in HL, and discuss implications for immunotherapy in this disease by targeting Treg cells. However, the origin, development, migration and functional mechanism of these Treg cells are under discussion.

RESULTS/CONCLUSION

As studies demonstrate that the depletion and/or manipulation of Treg cells enhance antitumor immunity, these novel treatment approaches may improve the therapy especially for patients with refractory or relapsed HL.

Endogenous IL-11 signaling is essential in Th2- and IL-13-induced inflammation and mucus production

IL-11 and IL-11 receptor (R)alpha are induced by Th2 cytokines. However, the role(s) of endogenous IL-11 in antigen-induced Th2 inflammation has not been fully defined. We hypothesized that IL-11, signaling via IL-11Ralpha, plays an important role in aeroallergen-induced Th2 inflammation and mucus metaplasia. To test this hypothesis, we compared the responses induced by the aeroallergen ovalbumin (OVA) in wild-type (WT) and IL-11Ralpha-null mutant mice. We also generated and defined the effects of an antagonistic IL-11 mutein on pulmonary Th2 responses. Increased levels of IgE, eosinophilic tissue and bronchoalveolar lavage (BAL) inflammation, IL-13 production, and increased mucus production and secretion were noted in OVA-sensitized and -challenged WT mice. These responses were at least partially IL-11 dependent because each was decreased in mice with null mutations of IL-11Ralpha. Importantly, the administration of the IL-11 mutein to OVA-sensitized mice before aerosol antigen challenge also caused a significant decrease in OVA-induced inflammation, mucus responses, and IL-13 production. Intraperitoneal administration of the mutein to lung-specific IL-13-overexpressing transgenic mice also reduced BAL inflammation and airway mucus elaboration. These studies demonstrate that endogenous IL-11R signaling plays an important role in antigen-induced sensitization, eosinophilic inflammation, and airway mucus production. They also demonstrate that Th2 and IL-13 responses can be regulated by interventions that manipulate IL-11 signaling in the murine lung.

IL-13 receptor alpha2 selectively inhibits IL-13-induced responses in the murine lung

IL-13 is a critical cytokine at sites of Th2 inflammation. In these locations it mediates its effects via a receptor complex, which contains IL-4Ralpha and IL-13Ralpha1. A third, high-affinity IL-13 receptor, IL-13Ralpha2, also exists. Although it was initially felt to be a decoy receptor, this has not been formally demonstrated and the role(s) of this receptor has recently become controversial. To define the role(s) of IL-13Ralpha2 in IL-13-induced pulmonary inflammation and remodeling, we compared the effects of lung-targeted transgenic IL-13 in mice with wild-type and null IL-13Ralpha2 loci. We also investigated the effect of IL-13Ralpha2 deficiency on the OVA-induced inflammatory response. In this study, we show that in the absence of IL-13Ralpha2, IL-13-induced pulmonary inflammation, mucus metaplasia, subepithelial fibrosis, and airway remodeling are significantly augmented. These changes were accompanied by increased expression and production of chemokines, proteases, mucin genes, and TGF-beta1. Similarly, an enhanced inflammatory response was observed in an OVA-induced phenotype. In contrast, disruption of IL-13Ralpha2 had no effect on the tissue effects of lung-targeted transgenic IL-4. Thus, IL-13Ralpha2 is a selective and powerful inhibitor of IL-13-induced inflammatory, remodeling, and physiologic responses in the murine lung.

Low-dose paclitaxel prior to intratumoral dendritic cell vaccine modulates intratumoral cytokine network and lung cancer growth

PURPOSE

The main goal of this study was to provide the "proof-of-principle" that low-dose paclitaxel is able to change the tumor microenvironment and improve the outcome of intratumoral dendritic cell vaccine in a murine lung cancer model.

EXPERIMENTAL DESIGN

We evaluated the antitumor potential and changes in the intratumoral milieu of a combination of low-dose chemotherapy and dendritic cell vaccine in the Lewis lung carcinoma model in vivo.

RESULTS

The low-dose paclitaxel, which induced apoptosis in approximately 10% of tumor cells, was not toxic to bone marrow cells and dendritic cells and stimulated dendritic cell maturation and function in vitro. Although tumor cells inhibited dendritic cell differentiation in vitro, this immunosuppressive effect was abrogated by the pretreatment of tumor cells with low-dose paclitaxel. Based on these data, we next tested whether pretreatment of tumor-bearing mice with low-dose paclitaxel in vivo would improve the antitumor potential of dendritic cell vaccine administered intratumorally. Significant inhibition of tumor growth in mice treated with low-dose paclitaxel plus intratumoral dendritic cell vaccine, associated with increased tumor infiltration by CD4(+) and CD8(+) T cells and elevated tumor-specific IFN-gamma production by draining lymph node cells, was revealed. Using a novel intratumoral microdialysis technique and Luminex technology for collecting and characterizing soluble factors released within the tumor bed for several days in live freely moving animals, we showed that low-dose paclitaxel altered the cytokine network at the tumor site.

CONCLUSIONS

Our data indicate that low-dose chemotherapy before intratumoral delivery of dendritic cells might be associated with beneficial alterations of the intratumoral microenvironment and thus support antitumor immunity.

Fibrosis in Hodgkin and non-Hodgkin lymphomas

There is little quantitative information about the amount of fibrosis in lymphomas. The aim of the present study was to investigate the amount of fibrosis in lymphomas and to highlight the relationship between fibrosis and mast cells, the key players of fibrosis. Tissue sections of 60 patients with diagnosis of lymphoma were reevaluated for classification. The mean fibrotic-stained area percentage (F-SAP) was determined in van Gieson-stained digital images using image analysis (Mediscope, Dokuz Eylul University, Clinical Engineering, Turkey). Mast cells were visualized using streptavidin peroxidase immunohistochemistry with anti-tryptase staining. Twenty-seven (44%) cases were Hodgkin's lymphoma (HL). F-SAP was 11.09+/-8.96 and 1.72+/-1.76 for HL and non-HL cases (Mann-Whitney U, p<0.000), and the mean mast cell count (MMCC) was 24.63+/-13.58 and 8.03+/-8.07, respectively (Mann-Whitney U test, p<0.000). There was a significant difference between F-SAP and MMCC concerning different types of lymphomas (Kruskal-Wallis test, p>0.000). F-SAP was highest in nodular sclerosis HL, and MMCC was highest in mixed cellular HL. There was a strong positive correlation between MMCC and F-SAP (Pearson Correlation test, p<0.000, r=0.51). These results suggest that the amount of fibrosis demonstrates differences in subtypes of lymphomas, and mast cells are increased in fibrosing lymphomas. However, it seems likely that more than one cell type is involved.

Implication de l'interleukine 13 et de son récepteur dans la sclérodermie systémique

PURPOSE

Interleukin 13 is an immunoregulatory cytokine predominantly secreted by activated Th2 cells. It has similar functions with interleukin 4 and they share a common receptor. However, unlike interleukin 4, l'interleukin 13 does not appear to be important in the initial differentiation of CD4 T into Th2-type cells, but rather appears to be necessary in the effector phase of inflammation and fibrosis. This cytokine has been involved in recent works in allergic inflammation and in some fibrotic diseases leading to a scientific interest to analysis the role of interleukin 13 in systemic sclerosis (scleroderma).

MAIN POINTS

Systemic sclerosis is an autoimmune disease characterized by vascular alteration and skin and visceral fibrosis. A genetic background associated with susceptibility is supposed. Knowing the profibrogenic properties of interleukin 13, we asked if polymorphisms located in interleukin 13 and interleukin 13 receptor genes could be associated with systemic sclerosis. We observed significant associations between IL13 and IL13RA2 gene polymorphisms and the disease, particularly the cutaneous diffuse form of the disease.

PERSPECTIVES AND PROJECTS

Results concerning the involvement of interleukin 13 pathway in systemic sclerosis need to be confirmed on another larger population. Functional studies will be done to explain the effect of these associations. We feel that IL13/IL13R pathway is interesting as immunomodulation with the interleukin 13 receptor inhibitor is possible in therapy.

Evaluation of interleukin 13 polymorphisms in systemic sclerosis

Systemic sclerosis (SSc) is a multisystem disease of unknown etiology. It is characterized by excessive cutaneous and visceral fibrosis, damage to small blood vessels, and production of autoantibodies. Interleukin-13 (IL-13) has been shown to be involved in abnormal fibrosis in other diseases. Therefore, we have evaluated its possible involvement in SSc. We analyzed four IL13 gene polymorphisms, rs1800925 (IL13-1055), rs20541 (Arg130Gln), rs847, and rs2243204 in 107 unrelated SSc patients (40 patients having diffuse cutaneous form and 67 patients having limited cutaneous form) and in 170 controls. All subjects were Caucasians. In the total patient population and in the diffuse cutaneous subset, we observed an association between two IL13 polymorphisms, IL13 rs1800925 (IL13-1055), and IL13 rs2243204, and disease (p=0.03-0.04). The IL13 rs2243204T allele was more common in SSc patients (p=0.01, OR=2.3 CI 1.21-4.38) and in the diffuse cutaneous form (p=0.01, OR=2.95, CI 1.35-6.49) than in control subjects. Our result supports the suggestion that polymorphisms in IL13 are associated to SSc and skin fibrosis process. However, further studies on larger and independent population and functional analyses are needed to confirm these findings.

Bioregulators as prototypic nontraditional threat agents

Bioregulators are naturally occurring organic compounds that regulate a multitude of biologic processes. Under natural circumstances, bioregulators are synthesized in minute quantities in a variety of living organisms and are essential for physiologic homeostasis. In the wrong hands, these compounds have the capability to be used as nontraditional threat agents that are covered by the prohibitions of the Chemical Weapons Convention and the Biological and Toxin Weapons Convention. Unlike traditional biowarfare/bioterrorism agents that have a latency period of hours to days,the onset of action of bioregulators may occur within minutes after host exposure. Concerns regarding the potential misuse of bioregulators for nefarious purposes relate to the ability of these nontraditional agents to induce profound physiologic effects.

Minimal change nephrotic syndrome and classical Hodgkin's lymphoma: Report of 21 cases and review of the literature

Minimal change nephrotic syndrome (MCNS) is described as a paraneoplastic manifestation of classical Hodgkin's lymphoma (cHL). We reassessed the pathophysiological and clinical significance of this association. A retrospective study was performed to evaluate a cohort of adult patients who developed MCNS and cHL. Twenty-one patients recruited in 15 French centers were analyzed. cHL was associated with inflammatory and general symptoms in most cases. The morphological subtype was predominantly nodular sclerosis (71.4%). MCNS appeared before the diagnosis of lymphoma in eight patients (38.1%) and in this case, it was characterized by a nephrotic syndrome (NS) frequently resistant (50%) or dependent (12.5%) to steroid treatment. Interestingly, diagnosis (3-120 months after MCNS) and effective treatment of the hemopathy were associated with the disappearance of the MCNS. cHL was diagnosed before MCNS in nine patients (42.9%), and in this case, glomerulopathy was associated with cHL relapse in 55.5% of cases. In four patients (19%), the two diseases occurred simultaneously. Extensive immunohistochemical study of lymph nodes was performed in eight patients and did not reveal particular features. In conclusion, MCNS associated with cHL is frequently dependent or resistant to steroid regimen, but remission of NS is obtained with the cure of lymphoma.

Genomic Alterations in Hodgkin's Lymphoma

Cytogenetic analysis of Hodgkin's lymphoma (HL) is hampered by the scarcity of neoplastic cells within a sea of reactive cells. There is accumulating evidence that HL represents 2 disease entities, classic HL (cHL) with its morphologic variants and nodular lymphocyte predominant HL (NLPHL). This subdivision, initially worked out in morphologic and immunohistochemical studies, has been further substantiated by molecular cytogenetic investigations. Two recurrent chromosomal aberrations, namely gains of 2p13-p16 and 9p24, have been found by comparative genomic hybridization analysis in microdissected cells from cHL patients as well as in cHL cell lines, but not in NLPHL cells. The available cHL cell lines are remarkably heterogeneous in their karyotypes, suggesting profound genomic instability leading to numeric chromosomal aberration and multiple chromosomal breaks and translocations. In this article, we review genomic aberrations that may contribute to the development and maintenance of the morphologic and clinical presentation of these beta-cell lymphoma entities. Furthermore, we delineate current data on the genomic changes observed in the neoplastic cells of HL that are created by epigenetic mechanisms, which are alternative mechanisms that regulate the expression of relevant genes.

Epstein-Barr virus, cytokines, and inflammation: a cocktail for the pathogenesis of Hodgkin's lymphoma?

The association between chronic inflammation and cancer has been known for well over a century. However, direct evidence detailing the role of inflammation in carcinogenesis has been slow in forthcoming. A number of recent studies suggest that the gaps in our understanding of the molecular pathways bridging the link between inflammation and cancer are slowly beginning to close and that this relationship is more deep-rooted than had been previously believed. This review addresses the link between inflammation and Hodgkin's lymphoma (HL), a malignancy which has many features reminiscent of chronic inflammation. The role of Epstein-Barr virus (EBV) in the pathogenesis of HL is discussed, along with an outline of our current understanding of the cellular nature and development of Reed-Sternberg cells, the malignant cells of HL. The involvement of cytokines and chemokines as orchestrators of inflammation and vehicles for chemical cross-talk between the malignant cells and the reactive inflammatory infiltrate forms a major part of the review. It is suggested that chronic inflammation, triggered by factors such as EBV, is likely to contribute to tumor cell proliferation, progression, and inhibition of apoptosis. Furthermore, it is proposed that the pro-inflammatory transcription factor NF-kappaB plays a central role in many of these processes.

Role of CCR5 in the Pathogenesis of IL-13-Induced Inflammation and Remodeling

IL-13 is a major effector at sites of Th2 inflammation and tissue remodeling. In these locations, it frequently coexists with the CCR5 chemokine receptor and its ligands MIP-1alpha/CCL3 and MIP-1beta/CCL4. We hypothesized that CCR5 induction and activation play important roles in the pathogenesis of IL-13-induced tissue responses. To test this hypothesis, we evaluated the effects of IL-13 on the expression of CCR5 in the murine lung. We also compared the effects of lung-targeted transgenic IL-13 in mice treated with anti-CCR5 or an Ab control and mice with wild-type or null CCR5 loci. These studies demonstrate that IL-13 is a potent stimulator of epithelial cell CCR5 expression. They also demonstrate that CCR5 neutralization or a deficiency of CCR5 significantly decreases IL-13-induced inflammation, alveolar remodeling, structural and inflammatory cell apoptosis, and respiratory failure and death. Lastly, these studies provide mechanistic insights by demonstrating that CCR5 is required for optimal IL-13 stimulation of select chemokines (MIP-1alpha/CCL3, MIP-1beta/CCL4, MCP-1/CCL-2), matrix metalloproteinase-9 and cell death regulators (Fas, TNF, TNFR1, TNFR2, Bid), optimal IL-13 inhibition of alpha1-antitrypsin, and IL-13-induction of and activation of caspases-3, -8, and-9. Collectively, these studies demonstrate that CCR5 plays a critical role in the pathogenesis of IL-13-induced inflammation and tissue remodeling.

Role of early growth response-1 (Egr-1) in interleukin-13-induced inflammation and remodeling

IL-13 is an important stimulator of inflammation and tissue remodeling at sites of Th2 inflammation, which plays a key role in the pathogenesis of a variety of human disorders. We hypothesized that the ubiquitous transcription factor, early growth response-1 (Egr-1), plays a key role in IL-13-induced tissue responses. To test this hypothesis we compared the expression of Egr-1 and related moieties in lungs from wild type mice and transgenic mice in which IL-13 was overexpressed in a lung-specific fashion. We simultaneously characterized the effects of a null mutation of Egr-1 on the tissue effects of transgenic IL-13. These studies demonstrate that IL-13 stimulates Egr-1 via an Erk1/2-independent Stat6-dependent pathway(s). They also demonstrate that IL-13 is a potent stimulator of eosinophil- and mononuclear cell-rich inflammation, alveolar remodeling, and tissue fibrosis in mice with wild type Egr-1 loci and that these alterations are ameliorated in the absence of Egr-1. Lastly, they provide insights into the mechanisms of these processes by demonstrating that IL-13 stimulates select CC and CXC chemokines (MIP-1alpha/CCL-3, MIP-1beta/CCL-4, MIP-2/CXCL2/3, MCP-1/CCL-2, MCP-2/CCL-8, MCP-3/CCL-7, MCP-5/CCL-12, KC/CXCL-1, and Lix/CXCL-5), matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1, and apoptosis regulators (caspase-3, -6, -8, and -9 and Bax) and activates transforming growth factor-beta1 and pulmonary caspases via Egr-1-dependent pathways. These studies demonstrate that Egr-1 plays a key role in the pathogenesis of IL-13-induced inflammatory and remodeling responses.

Regulation of Fibrosis by the Immune System

Inflammation and fibrosis are two inter-related conditions with many overlapping mechanisms. Three specific cell types, macrophages, T helper cells, and myofibroblasts, each play important roles in regulating both processes. Following tissue injury, an inflammatory stimulus is often necessary to initiate tissue repair, where cytokines released from resident and infiltrating leukocytes stimulate proliferation and activation of myofibroblasts. However, in many cases this drive stimulates an inappropriate pro-fibrotic response. In addition, activated myofibroblasts can take on the role of traditional APCs, secrete pro-inflammatory cytokines, and recruit inflammatory cells to fibrotic foci, amplifying the fibrotic response in a vicious cycle. Moreover, inflammatory cells have been shown to play contradictory roles in initiation, amplification, and resolution of fibrotic disease processes. The central role of the macrophage in contributing to the fibrotic response and fibrotic resolution is only beginning to be fully appreciated. In the following review, we discuss the fibrotic disease process from the context of the immune response to injury. We review the major cellular and soluble factors controlling these responses and suggest ways in which more specific and, hopefully, more effective therapies may be derived.

Cytokine gene expression profile distinguishes CD4+/CD57+ T cells of the nodular lymphocyte predominance type of Hodgkin's lymphoma from their tonsillar counterparts

Little is known about the cytokine profile of nodular lymphocyte predominance Hodgkin's lymphoma (NLPHL) and the significance of the characteristic rosetting CD4(+)/CD57(+) T cells. We analysed the T lymphocyte populations isolated from lymph node suspensions from five patients with NLPHL, two with follicular hyperplasia and progressive transformation of germinal centres (PTGC), three with classical Hodgkin's lymphoma (CHL) and five with hyperplasia of the tonsil. We sorted the T cells based on expression of CD3, CD4 and CD57 by flow cytometry and evaluated the cytokine mRNA profiles of the T cells with quantitative RT-PCR. NLPHL cases were as rich in T cells as the CHL cases, but all NLPHL cases had a much higher frequency of CD4(+)/CD57(+) T cells. In contrast to the CD4(+)/CD57(+) T cells from tonsils, IL2 and IL4 mRNAs were consistently absent from the CD4(+)/CD57(+) T cells of NLPHL. Even after stimulation, no IL4 transcripts could be detected in the CD4(+)/CD57(+) T cells of NLPHL. On the other hand, IFNgamma transcripts were elevated in NLPHL and PTGC T cell subsets as compared to tonsillar T cell subsets. IL13 mRNA was exclusively produced by the T cells of CHL cases, indicating that IL13 may be a key cytokine in CHL. In conclusion, elevated levels of CD4(+)/CD57(+) T cells are characteristic of NLPHL and these T cells display a distinct cytokine mRNA profile.

ERK1/2 mitogen-activated protein kinase selectively mediates IL-13-induced lung inflammation and remodeling in vivo

IL-13 dysregulation plays a critical role in the pathogenesis of a variety of inflammatory and remodeling diseases. In these settings, STAT6 is believed to be the canonical signaling molecule mediating the tissue effects of IL-13. Signaling cascades involving MAPKs have been linked to inflammation and remodeling. We hypothesized that MAPKs play critical roles in effector responses induced by IL-13 in the lung. We found that Tg IL-13 expression in the lung led to potent activation of ERK1/2 but not JNK1/2 or p38. ERK1/2 activation also occurred in mice with null mutations of STAT6. Systemic administration of the MAPK/ERK kinase 1 (MEK1) inhibitor PD98059 or use of Tg mice in which a dominant-negative MEK1 construct was expressed inhibited IL-13-induced inflammation and alveolar remodeling. There were associated decreases in IL-13-induced chemokines (MIP-1alpha/CCL-3, MIP-1beta/CCL-4, MIP-2/CXCL-1, RANTES/CCL-5), MMP-2, -9, -12, and -14, and cathepsin B and increased levels of alpha1-antitrypsin. IL-13-induced tissue and molecular responses were noted that were equally and differentially dependent on ERK1/2 and STAT6 signaling. Thus, ERK1/2 is activated by IL-13 in the lung in a STAT6-independent manner where it contributes to IL-13-induced inflammation and remodeling and is required for optimal IL-13 stimulation of specific chemokines and proteases as well as the inhibition of specific antiproteases. ERK1/2 regulators may be useful in the treatment of IL-13-induced diseases and disorders.

Molecular pathogenesis of Hodgkin's lymphoma

According to the WHO classification, Hodgkin's lymphoma (HL) is subdivided into a classical variant and a nodular lymphocyte predominant variant which are characterized by the presence of Hodgkin's and Reed-Sternberg (H-RS) cells or lymphocytic and histiocytic (L&H) cells, respectively. This article reviews genetic characteristics and transcriptional changes of H-RS and L&H cells, including recent knowledge about transforming mechanisms and signaling pathways that contribute to the antiapoptotic phenotype displayed by H-RS and L&H cells. We also discuss major cellular and molecular mediators contributing to the establishment and maintenance of a reactive background in HL-affected tissues. We believe that an in-depth understanding of the pathogenesis of HL will eventually lead to the development of novel biologically based therapeutic strategies in the near future.

IL-11 receptor alpha in the pathogenesis of IL-13-induced inflammation and remodeling

IL-13 is a major stimulator of inflammation and tissue remodeling at sites of Th2 inflammation. In Th2-dominant inflammatory disorders such as asthma, IL-11 is simultaneously induced. However, the relationship(s) between IL-11 and IL-13 in these responses has not been defined, and the role(s) of IL-11 in the genesis of the tissue effects of IL-13 has not been evaluated. We hypothesized that IL-11, signaling via the IL-11Ralpha-gp130 receptor complex, plays a key role in IL-13-induced tissue responses. To test this hypothesis we compared the expression of IL-11, IL-11Ralpha, and gp130 in lungs from wild-type mice and transgenic mice in which IL-13 was overexpressed in a lung-specific fashion. We simultaneously characterized the effects of a null mutation of IL-11Ralpha on the tissue effects of transgenic IL-13. These studies demonstrate that IL-13 is a potent stimulator of IL-11 and IL-11Ralpha. They also demonstrate that IL-13 is a potent stimulator of inflammation, fibrosis, hyaluronic acid accumulation, myofibroblast accumulation, alveolar remodeling, mucus metaplasia, and respiratory failure and death in mice with wild-type IL-11Ralpha loci and that these alterations are ameliorated in the absence of IL-11Ralpha. Lastly, they provide insight into the mechanisms of these processes by demonstrating that IL-13 stimulates CC chemokines, matrix metalloproteinases, mucin genes, and gob-5 and stimulates and activates TGF-beta1 via IL-11Ralpha-dependent pathways. When viewed in combination, these studies demonstrate that IL-11Ralpha plays a key role in the pathogenesis of IL-13-induced inflammation and remodeling.

Interactions between tissue fibroblasts in lymph nodes and Hodgkin/Reed-Sternberg cells

Classic Hodgkin's Disease (cHD) is a lymphoid neoplasia characterized by a few malignant Hodgkin and Reed-Sternberg (H-RS) cells embedded in an abundant background of non-tumor cells. In this context, fibrosis is a common morphologic feature of HD lesions, being found more frequently in cHD subtypes. The clinical and histopathologic features of cHD are thought to be largely due to the effects of a wide variety of cytokines and chemokines primarily produced by H-RS cells, as well as by the surrounding reactive component. In the present review, first we propose three mechanisms putatively explaining fibroblast activation and fibrosis in HD: (1) unbalanced production of the pro-fibrogenic Th2 over Th1 cytokines; (2) production of TGF-beta, b-FGF and IL-13 by H-RS cells; (3) activation of fibroblasts by CD40L-expressing cells of the HD microenvironment. Second, we suggest some molecular pathways involving cytokines produced by HD-derived fibroblasts (SCF, IL-7, IL-6) supposedly responsible for H-RS proliferation and rescue from apoptosis. Finally, we describe the role of specific molecules produced by H-RS cells in the regulation of HD-derived fibroblast production of chemokines, in turn involved in T-lymphocytes and recruitment of eosinophils.

[Classical Hodgkin's lymphoma: biology and grey zones]

Advances in the biology of Hodgkin's lymphoma have lead to the distinction between two entities, "classical" Hodgkin's lymphoma and nodular lymphocyte predominance Hodgkin's lymphoma, previously called nodular paragranuloma, which share distinct clinical aspects. The definition of diagnostic criteria has also been helpful to separate Hodgkin's lymphoma from other lymphomas which can mimick Hodgkin's disease such as anaplastic large cell lymphomas, T-cell/histiocyte rich diffuse large B-cell lymphoma, and some peripheral T-cell lymphomas, mainly angioimmunoblastic-type. Reed-Sternberg cell, the neoplastic cell of "classical" Hodgkin's lymphoma, still retains some secrets. Despite some controversies, there is more and more evidence for a lymphoid B cell origin. The involvement of Epstein-Barr virus, cytokines and/or oncogenes expression in the pathogeny can be suggested, although the precise mechanisms leading to transformation and/or accounting for tumour progression are still elusive. Recently, the roles of the pathway implicating the activation of NFkappaB as well as the autocrine secretion of interleukin-13 have been demonstrated.

The C10/CCL6 chemokine and CCR1 play critical roles in the pathogenesis of IL-13-induced inflammation and remodeling

IL-13 is a potent stimulator of inflammation and tissue remodeling that plays a key role in the pathogenesis of a wide variety of human disorders. To further understand these responses, studies were undertaken to define the role(s) of the chemokine C10/CCL6 in the pathogenesis of IL-13-induced alterations in the murine lung. IL-13 was a very potent stimulator of C10/CCL6 mRNA and protein, and IL-13-induced inflammation, alveolar remodeling, and compliance alterations were markedly ameliorated after C10/CCL6 neutralization. Treatment with anti-C10/CCL6 decreased the levels of mRNA encoding matrix metalloproteinase-2 (MMP-2), MMP-9, and tissue inhibitor of metalloproteinase-4 (TIMP-4) in lungs from wild-type mice. C10/CCL6 neutralization also decreased the ability of IL-13 to stimulate the production of monocyte chemoattractant protein-1, macrophage inflammatory protein-1alpha, MMP-2, MMP-9, and cathepsins-K, -L, and -S and the ability of IL-13 to inhibit alpha1-antitrypsin. In accord with these findings, a targeted null mutation of CCR1, a putative C10/CCL6 receptor, also decreased IL-13-induced inflammation and alveolar remodeling and caused alterations in chemokines, proteases, and antiproteases comparable to those seen after C10/CCL6 neutralization. These C10/CCL6 and CCR1 manipulations did not alter the production of transgenic IL-13. These studies demonstrate that IL-13 is a potent stimulator of C10/CCL6 and highlight the importance of C10/CCL6 and signaling via CCR1 in the pathogenesis of the IL-13-induced pulmonary phenotype. They also describe a C10/CCL6 target gene cascade in which C10/CCL6 induction is required for optimal IL-13 stimulation of selected chemokines (monocyte chemoattractant protein-1 and MIP-1alpha) and proteases (MMP-2, MMP-9, and cathepsins-K, -L, and -S) and the inhibition of alpha1-antitrypsin.

Hodgkin and non-Hodgkin lymphoma involving bone marrow

The role of bone marrow examination in diagnosis and staging of patients with Hodgkin lymphoma, B-non-Hodgkin lymphoma, and T-non-Hodgkin lymphoma is reviewed. Optimal routine and specialized bone marrow examination techniques are discussed. The salient morphologic, immunophenotypic, and genetic features of mature and immature B, T neoplasms and classic Hodgkin lymphoma in bone marrow are delineated, along with recommendations to distinguish these overt neoplasms from non-neoplastic processes.

Soluble Interleukin-13Rα2 Decoy Receptor Inhibits Hodgkin’s Lymphoma Growth in Vitro and in Vivo

Recent studies have demonstrated that the malignant Reed-Sternberg cells of Hodgkin's lymphoma (HL) secrete and are responsive to interleukin (IL)-13. We hypothesized that overexpression of a soluble IL-13 decoy receptor (sIL-13Ralpha2) via adenoviral-mediated gene transfer would inhibit IL-13-induced Reed-Sternberg cell proliferation. Western blot and ELISA analysis verified expression of sIL-13Ralpha2 in cell lysates and supernatants of AdsIL-13Ralpha2-transduced COS-7 cells. Treatment of two IL-13-responsive HL-derived cell lines, HDLM-2 and L-1236, with AdsIL-13Ralpha2-conditioned medium, resulted in the inhibition of cell proliferation, and down-regulated the phosphorylation of signal transducer and activator of transcription 6 (STAT6), an important mediator of IL-13 signaling. i.v. delivery of AdsIL-13Ralpha2 in NOD/SCID mice with s.c. implanted HDLM-2 cells delayed tumor onset and growth while enhancing survival compared with control mice. Intratumoral administration of AdsIL-13Ralpha2 led to the regression or stabilization of established tumors and was associated with diminished STAT6 phosphorylation. Our data demonstrate that AdsIL-13Ralpha2 can suppress HL growth in vitro and in vivo.