Th1/Th2 cytokine expression and its relationship with tumor growth in B cell non-Hodgkin's lymphoma (NHL)

Long-Term Suppression of Circulating Proinflammatory Cytokines in Multiple Sclerosis Patients Following Autologous Haematopoietic Stem Cell Transplantation

Autologous haematopoietic stem cell transplantation (AHSCT) is a therapeutic option for haematological malignancies, such as non-Hodgkin’s lymphoma (NHL), and more recently, for autoimmune diseases, such as treatment-refractory multiple sclerosis (MS). The immunological mechanisms underlying remission in MS patients following AHSCT likely involve an anti-inflammatory shift in the milieu of circulating cytokines. We hypothesised that immunological tolerance in MS patients post-AHSCT is reflected by an increase in anti-inflammatory cytokines and a suppression of proinflammatory cytokines in the patient blood. We investigated this hypothesis using a multiplex-ELISA assay to compare the concentrations of secreted cytokine in the peripheral blood of MS patients and NHL patients undergoing AHSCT. In MS patients, we detected significant reductions in proinflammatory T helper (Th)17 cytokines interleukin (IL)-17, IL-23, IL-1β, and IL-21, and Th1 cytokines interferon (IFN)γ and IL-12p70 in MS patients from day 8 to 24 months post-AHSCT. These changes were not observed in the NHL patients despite similar pre-conditioning treatment for AHSCT. Some proinflammatory cytokines show similar trends in both cohorts, such as IL-8 and tumour necrosis factor (TNF)-α, indicating a probable treatment-related AHSCT response. Anti-inflammatory cytokines (IL-10, IL-4, and IL-2) were only transiently reduced post-AHSCT, with only IL-10 exhibiting a significant surge at day 14 post-AHSCT. MS patients that relapsed post-AHSCT exhibited significantly elevated levels of IL-17 at 12 months post-AHSCT, unlike non-relapse patients which displayed sustained suppression of Th17 cytokines at all post-AHSCT timepoints up to 24 months. These findings suggest that suppression of Th17 cytokines is essential for the induction of long-term remission in MS patients following AHSCT.

Downregulation of CCL22 and mutated NOTCH1 in tongue and mouth floor squamous cell carcinoma results in decreased Th2 cell recruitment and expression, predicting poor clinical outcome

OBJECTIVE

Tongue and mouth floor squamous cell carcinoma (T/MF SCC) exhibits a high rate of local recurrence and cervical lymph node metastasis. The effect of the tumor microenvironment on T/MF SCC remains unclear.

MATERIALS AND METHODS

Transcriptome and somatic mutation data of patients with T/MF SCC were obtained from HNSC projects of the Cancer Genome Atlas. Immune infiltration quantification in early- (clinical stage I-II) and advanced-stage (clinical stage III-IV) T/MF SCC was performed using single sample Gene Set Enrichment Analysis and MCPcounter. Differentially expressed gene data were filtered, and their function was assessed through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. Kaplan-Meier survival curve analysis and Cox regression model were conducted to evaluate the survival of patients with the CCL22 signature. Maftools was used to present the overview of somatic mutations.

RESULTS

In T/MF SCC, T helper (Th)2 cell counts were significantly increased in patients with early-stage disease compared to those with advanced-stage disease. Expression of the Th2 cell-related chemokine, CCL22, was downregulated in patients with advanced-stage T/MF SCC. Univariate and multivariate Cox analyses revealed that CCL22 was a good prognostic factor in T/MF SCC. A nomogram based on the expression of CCL22 was constructed to serve as a prognostic indicator for T/MF SCC. NOTCH1 mutations were found at a higher rate in patients with advanced-stage T/MF SCC than in those with early-stage T/MF SCC, resulting in the inhibition of the activation of the NOTCH1-Th2 cell differentiation pathway. The expression levels of CCL22, GATA-3, and IL4 were higher in patients with early-stage T/MF SCC than in those with advanced-stage T/MF SCC.

CONCLUSION

In T/MF SCC, high expression of CCL22 may promote the recruitment of Th2 cells and help predict a better survival. Mutations in NOTCH1 inhibit the differentiation of Th2 cells, facilitating tumor progression through a decrease in Th2 cell recruitment and differentiation.

NLRP3-activated bone marrow dendritic cells play antileukemic roles via IL-1β/Th1/IFN-γ in acute myeloid leukemia

The bone marrow microenvironment of acute myeloid leukemia (AML) characterized by immunosuppressive features fosters leukemia immune escape. Elucidating the immunosuppressive mechanism and developing effective immunotherapeutic strategies are necessary. Here, we found that the Th1% and IFN-γ level were downregulated in bone marrow of AML and NLRP3-activated BMDCs promoted CD4⁺ T cell differentiation into Th1 cells via IL-1β secretion. However, IFN-γ-producing Th1 cells were not induced by NLRP3-activated BMDCs in the presence of the NLRP3 inflammasome inhibitor MCC950 or anti-IL-1β antibody in vitro unless exogenous IL-1β was replenished. This inhibitory effect on Th1 differentiation was also observed in Nlrp3^-/- mice or anti-IL-1β antibody-treated mice. Notably, elevated Th1 cell levels promoted apoptosis and inhibited proliferation in leukemia cells via IFN-γ secretion in vitro and in vivo. Thus, NLRP3-activated BMDCs promote the proliferation of IFN-γ-producing Th1 cells with antileukemic effects and may provide insight into the basis for leukemia immunotherapy in patients with AML.

Role of Microenvironment in Non-Hodgkin Lymphoma: Understanding the Composition and Biology

Lymphoma microenvironment is a dynamic and well-orchestrated network of various immune and stromal cells that is indispensable for tumor cell survival, growth, migration, immune escape, and drug resistance. Recent progress has enhanced our knowledge of the pivotal role of microenvironment in lymphomagenesis. Understanding the characteristics, functions, and contributions of various components of the tumor niche, along with its bidirectional interactions with tumor cells, is paramount. It offers the potential to identify new therapeutic targets with the ability to restore antitumor immune surveillance and eliminate the protumoral factors contributed by the tumor niche.

Understanding the Immune-Stroma Microenvironment in B Cell Malignancies for Effective Immunotherapy

Cancers, including lymphomas, develop in complex tissue environments where malignant cells actively promote the creation of a pro-tumoral niche that suppresses effective anti-tumor effector T cell responses. Research is revealing that the tumor microenvironment (TME) differs between different types of lymphoma, covering inflamed environments, as exemplified by Hodgkin lymphoma, to non-inflamed TMEs as seen in chronic lymphocytic leukemia (CLL) or diffuse-large B-cell lymphoma (DLBCL). In this review we consider how T cells and interferon-driven inflammatory signaling contribute to the regulation of anti-tumor immune responses, as well as sensitivity to anti-PD-1 immune checkpoint blockade immunotherapy. We discuss tumor intrinsic and extrinsic mechanisms critical to anti-tumor immune responses, as well as sensitivity to immunotherapies, before adding an additional layer of complexity within the TME: the immunoregulatory role of non-hematopoietic stromal cells that co-evolve with tumors. Studying the intricate interactions between the immune-stroma lymphoma TME should help to design next-generation immunotherapies and combination treatment strategies to overcome complex TME-driven immune suppression.

Higher Peripheral Blood IFN-γ-/IL-4+ Th2 Lymphocytes Are Associated with Lower Rate of Relapse in Patients with Lymphoma

BACKGROUND

The role of T-helper lymphocytes especially T helper 2 (Th2) subsets in lymphoid malignancies is debatable and unknown.

METHODS

Herein, we evaluated the polarization of the IFN-γ⁺/IL-4^- Th1 and IFN-γ^-/IL-4⁺ Th2 lymphocytes in 95 lymphoma patients including 47 classical Hodgkin's lymphoma (cHL) and 48 diffuse large B cell lymphoma patients (DLBCL) at different disease phases and its correlation with the clinical outcomes of patients using flow cytometry method.

RESULTS

The proportion of IFN-γ⁺/IL-4^- Th1 lymphocytes was significantly higher in cHL patients at remission compared to the newly diagnosed ones. Both cHL and DLBCL patients at remission phase had significantly more IFN-γ^-/IL-4⁺ Th2 lymphocytes than those patients at relapse/refractory phase as well as newly diagnosed ones. Despite having higher frequency of IFN-γ⁺/IL-4^- Th1 lymphocytes, the mean fluorescent intensity (MFI) of IFN-γ was lower in relapsed cHL patients, in those with high-risk IPI score, performance status (PS) ≥2 and B symptom-positive groups compared to their corresponding counterparts in newly diagnosed patients.

CONCLUSION

Taken together, higher peripheral blood IFN-γ^-/IL-4⁺ Th2 lymphocytes might be associated with a favorable prognosis like lower rate of relapse in lymphoma patients.

Canine multicentric lymphoma exhibits systemic and intratumoral cytokine dysregulation

Non-Hodgkin Lymphoma (NHL) is among the most common neoplasias in dogs and humans. Owing to remarkable similarities with its human counterpart, the canine lymphoma (cNHL) model has been proposed as a powerful framework for rapid and clinically relevant translation of novel immunotherapies. However, the establishment of cNHL as a predictive preclinical model has been hampered by the limited characterization of the canine immune system. Cytokines are key players of the interaction between tumor and its microenvironment. In human NHL, multiple cytokines have been linked to the development of lymphoma and are relevant biomarkers for treatment response and prognosis. In contrast, few studies have investigated cytokines in cNHL. Within this context, this study aimed to investigate cytokine regulation in cNHL. A multicentric cNHL biobank was successfully constructed. Cytokine mRNA profiles in tumor tissue and circulating PBMC were analyzed by qRT-PCR and compared to a healthy control group. Specific primers were used to evaluate Th1, Th2 and Th17 responses. Systemic cytokine concentrations were measured using a commercial canine multiplex assay which included IL-2, IL6, IL-10 and TNF-α, and compared to a healthy control group. Our results demonstrated a dysregulation of cytokine mRNA expression, representative of the tumor microenvironment and systemic response in cNHL. Intratumoral cytokine response revealed a significant downregulation of humoral and Th1 responses. The systemic response demonstrated a distinct mRNA pattern, however immunosuppression also prevailed. Cytokine serum quantification showed a significant increase of IL-10 concentration in cNHL. Significant differences in hematological parameters were described and a correlation between IL-6 protein serum levels and neutrophil count was shown. Finally, data analysis demonstrated that baseline pretreatment IFN-γ tissue mRNA levels were correlated to survival outcome, predicting a favorable response to chemotherapy. Altogether, these results revealed that cNHL presents a local and systemic dysregulation in cytokine response. By confirming and extending previous research, our work contributed for the evaluation of potential cytokine candidates for diagnostic, prognostic purposes and therapeutic intervention, therefore adding value to comparative oncology.

Activated Natural Killer Cells Mediate the Suppressive Effect of Interleukin-4 on Tumor Development via STAT6 Activation in an Atopic Condition Melanoma Model

A protective effect of allergy for cancer has been suggested, but the results are somewhat conflicting, and the mechanism remains elusive. Interleukin-4 (IL-4) signaling has been identified as a potentially important pathway in the development of allergies and the suppression of cancer development. To evaluate the allergy responses in IL-4–mediated tumor development, we compared the growth of B16F10 melanoma cells in 4% phthalic anhydride (PA)-treated IL-4/Luc/CNS-1 transgenic mice (IL-4 mice) and acetone-olive oil (AOO)–treated IL-4 mice as a control for 3 weeks. Much higher allergic responses and natural killer (NK) and STAT6 activation were found in PA-treated IL-4 mice compared with AOO-treated IL-4 control mice. Tumor volume and weight showed an inverse association with the higher allergic response and were significantly reduced in the PA-treated IL-4 mice when compared with those of AOO-treated IL-4 control mice. Significantly higher activation of STAT6, as well as IL-4 and NK cell activation, was found in the tumor tissues of PA-treated IL-4 mice. Infiltration of immune cells and cytokine levels were also higher in the tumor tissues of PA-treated IL-4 mice. We further found that IL-4–activated NK-92MI cells showed increased anticancer effects in human melanoma cells. Overall, these results showed that allergy responses further accelerated the IL-4–induced inhibition of tumor development through the activation of STAT6 pathways.

Tumor-targeted delivery of sunitinib base enhances vaccine therapy for advanced melanoma by remodeling the tumor microenvironment

Development of an effective treatment against advanced tumors remains a major challenge for cancer immunotherapy. We have previously developed a potent mannose-modified lipid calcium phosphate (LCP) nanoparticle (NP)-based Trp2 vaccine for melanoma therapy, but because this vaccine can induce a potent anti-tumor immune response only during the early stages of melanoma, poor tumor growth inhibition has been observed in more advanced melanoma models, likely due to the development of an immune-suppressive tumor microenvironment (TME). To effectively treat this aggressive tumor, a multi-target receptor tyrosine kinase inhibitor, sunitinib base, was efficiently encapsulated into a targeted polymeric micelle nano-delivery system (SUNb-PM), working in a synergistic manner with vaccine therapy in an advanced mouse melanoma model. SUNb-PM not only increased cytotoxic T-cell infiltration and decreased the number and percentage of MDSCs and Tregs in the TME, but also induced a shift in cytokine expression from Th2 to Th1 type while remodeling the tumor-associated fibroblasts, collagen, and blood vessels in the tumor. Additionally, inhibition of the Stat3 and AKT signaling pathways by SUNb-PM may induce tumor cell apoptosis or decrease tumor immune evasion. Our findings indicated that targeted delivery of a tyrosine kinase inhibitor to tumors can be used in a novel synergistic way to enhance the therapeutic efficacy of existing immune-based therapies for advanced melanoma.

Infiltrating neutrophils increase bladder cancer cell invasion via modulation of androgen receptor (AR)/MMP13 signals

Early studies indicated that several inflammatory immune cells, including macrophages, mast cells, B and T cells in the tumor microenvironment, might influence cancer progression. Here we found that bladder cancer (BCa) cells could recruit more neutrophils than normal bladder cells. The consequences of recruiting more neutrophils might then increase BCa cell invasion via up-regulating androgen receptor (AR) signals. Mechanism dissection revealed infiltrating neutrophils could up-regulate AR signals via either increased AR mRNA/protein expression or increased AR transactivation. The increased AR signals might then enhance BCa cell invasion via increasing MMP13 expression. Together, these results might provide us a new potential therapeutic approach to better battle BCa metastasis via targeting the newly identified signaling from infiltrating neutrophils to BCa through AR to MMP13 signals.

Targeting immune checkpoints in lymphoma

PURPOSE OF REVIEW

The purpose of this article is to discuss the tumor microenvironment in lymphoma, and to review potential immune targets that are now becoming relevant because of clinical responses seen with the use of immune checkpoint inhibitors.

RECENT FINDINGS

Recent data have shown that cells within the immune microenvironment in lymphoma express programmed death ligand-1 (PD-L1) and many of the intratumoral T cells with an exhausted immune phenotype express programmed cell death-1 (PD-1). This provides a novel opportunity to inhibit the immune checkpoints and initial clinical trials utilizing antibodies that block the interaction between PD-1 and PD-L1 have demonstrated significant clinical responses in various lymphomas, including Hodgkin lymphoma.

SUMMARY

The use of immune checkpoint inhibitors, including nivolumab and pembrolizumab, in relapsed and refractory patients with lymphoma is proving highly successful. Patients with Hodgkin lymphoma, in particular, have a very high response rate to PD-1 blockade and responses in these patients appear durable.

Macrophage migration inhibitory factor (MIF) enzymatic activity and lung cancer

The cytokine macrophage migration inhibitory factor (MIF) possesses unique tautomerase enzymatic activity, which contributes to the biological functional activity of MIF. In this study, we investigated the effects of blocking the hydrophobic active site of the tautomerase activity of MIF in the pathogenesis of lung cancer. To address this, we initially established a Lewis lung carcinoma (LLC) murine model in Mif-KO and wild-type (WT) mice and compared tumor growth in a knock-in mouse model expressing a mutant MIF lacking enzymatic activity (Mif (P1G)). Primary tumor growth was significantly attenuated in both Mif-KO and Mif (P1G) mice compared with WT mice. We subsequently undertook a structure-based, virtual screen to identify putative small molecular weight inhibitors specific for the tautomerase enzymatic active site of MIF. From primary and secondary screens, the inhibitor SCD-19 was identified, which significantly attenuated the tautomerase enzymatic activity of MIF in vitro and in biological functional screens. In the LLC murine model, SCD-19, given intraperitoneally at the time of tumor inoculation, was found to significantly reduce primary tumor volume by 90% (p < 0.001) compared with the control treatment. To better replicate the human disease scenario, SCD-19 was given when the tumor was palpable (at d 7 after tumor inoculation) and, again, treatment was found to significantly reduce tumor volume by 81% (p < 0.001) compared with the control treatment. In this report, we identify a novel inhibitor that blocks the hydrophobic pocket of MIF, which houses its specific tautomerase enzymatic activity, and demonstrate that targeting this unique active site significantly attenuates lung cancer growth in in vitro and in vivo systems.

PD-1 expression defines two distinct T-cell sub-populations in follicular lymphoma that differentially impact patient survival

To determine the biological and clinical relevance of programmed death 1 (PD-1) in follicular lymphoma (FL), we characterized PD-1⁺ T-cell subsets and assessed their biological function as well as potential clinical impact. We found that PD-1 is expressed on intratumoral CD4⁺ T cells with both bright and dim intensity, representing two different sub-populations of cells. By immunohistochemistry, we found that CD4⁺PD-1^high T cells predominantly reside in the lymph node follicles, while PD-1^low T cells are mainly located in an interfollicular pattern. Intratumoral CD4⁺PD-1^high T cells have a T_FH cell phenotype, express CXCR5, secrete IL-21 and are BCL-6 positive with no TIM-3 expression. In contrast, CD4⁺PD-1^low T cells have an exhausted phenotype, express TIM-3 and do not express BCL-6 and CXCR5. Functionally, CD4⁺PD-1^high T cells actively supported B-cell growth, while CD4⁺PD-1^low T cells displayed a reduced cytokine production and cell-signal transduction. Clinically, we observed that the numbers of CD4⁺ or CD8⁺PD-1^low T cells significantly correlate with a reduced overall survival in FL patients (P=0.007 and 0.04 respectively; n=32). In contrast, the number of CD4⁺PD-1^high T cells was not associated with patient outcome. Taken together, these results indicated that PD-1 expression defines two sub-populations with distinct functions that differentially impact patient outcome in FL.

Indolent lymphoma: follicular lymphoma and the microenvironment-insights from gene expression profiling

As shown with gene expression profiling (GEP), the development and progression of follicular lymphoma (FL) involves complex interactions between neoplastic B cells and the surrounding microenvironment. GEP further reveals that the tumor microenvironment may predict survival in patients with FL and influence the response to therapy and the risk of transformation. Here, we briefly review GEP technology and summarize the role of the tumor microenvironment in FL diagnosis, prognosis, and transformation. Genes expressed by infiltrating T cells and macrophages appear to be the most important predictors of survival, clinical behavior, and outcome. These findings provide a basis for future studies into the pathogenesis and pathophysiology of FL and may ultimately provide guidance in the choice of therapy and the identification of potential therapeutic targets.

Skin barrier dysfunction and low antimicrobial peptide expression in cutaneous T-cell lymphoma

PURPOSE

Atopic dermatitis is characterized by decreased expression of filaggrin and loricrin. Patients with atopic dermatitis often suffer from skin infections, which are also frequently seen in patients with cutaneous T-cell lymphoma (CTCL). In this study, we aimed to investigate the skin barrier in CTCL.

EXPERIMENTAL DESIGN

We assessed skin moisture and transepidermal water loss (TEWL) in patients with CTCL. We next examined mRNA expression levels of filaggrin, loricrin, and antimicrobial peptides (AMP) in skin samples of CTCL, using skin from healthy volunteers and patients with atopic dermatitis or psoriasis as controls. Immunostainings for filaggrin, loricrin, and S100 proteins were also performed.

RESULTS

Lower levels of skin moisture accompanied by higher levels of TEWL were seen in lesional skin of CTCL than in normal skin. CTCL lesional skin contained lower levels of filaggrin and loricrin mRNA than normal skin, which was also true with atopic dermatitis and psoriatic skin. mRNA expression levels of filaggrin in CTCL skin negatively correlated with disease severity markers. Expression levels of AMPs in lesional skin of CTCL and atopic dermatitis were significantly lower than in psoriatic skin. Immunohistochemistry confirmed decreased expression of filaggrin and loricrin in CTCL, atopic dermatitis, and psoriatic skin and enhanced expression of S100 proteins in psoriatic skin.

CONCLUSIONS

Our results show that there is barrier dysfunction in CTCL skin, similar to what is seen with atopic dermatitis skin. In addition, low AMP expression in CTCL skin was documented when compared with psoriatic skin, which may explain frequent infections that can occur in patients with CTCL.

Cellular composition of the tumor microenvironment

In addition to malignant cells, the tumor microenvironment also includes nonmalignant cells, secreted proteins, and blood vessels that surround and support the growth of the tumor. Interactions between the various components of the tumor microenvironment are significant; tumor cells can change the nature of the microenvironment, and conversely, the microenvironment can affect how a tumor grows and spreads. The structure and composition of the tumor microenvironment varies among different types of cancers and between patients. This paper focuses on the composition and function of the tumor microenvironment in hematologic malignancies with a specific focus on B-cell lymphomas.

Immune function in newly diagnosed children with malignancy

BACKGROUND

Tumor genesis of many pediatric malignancies remains unclear. Data of immune function are lacking at diagnosis. We prospectively analyzed 109 pediatric patients with malignancy at diagnosis.

METHODS

Lymphocyte subpopulations were characterized by FACS, TREC-assay, and Immunoscope, cytokines by FACS and ELISA.

OBSERVATIONS

We detected higher values of CD4(+) T cells and consecutively shifted CD4(+)/CD8(+) ratio in all patients compared with the control group. In patients with lymphoma, interleukin-2 was upregulated in all subpopulations.

CONCLUSIONS

On the basis of these findings an altered immune function could be found in children with different malignancies at diagnosis. Further investigations are necessary to identify tumor-related immune deficiency for novel therapeutic approaches.

Interleukin-12: clinical usage and molecular markers of cancer susceptibility

The last decade has seen the emergence of immunomodulators as therapeutic agents in cancer treatment. Interleukins (ILs) are a category of small cell-signaling molecules that organize communication and interaction between immune cells and therefore they could be used as perfect immunomodulators. IL-12 is a promising candidate for cancer immunotherapy since it plays a major role in development of antitumor immune response. Numerous studies report that IL-12 promotes an effective destruction of cancer cells both in vivo and in vitro. In addition, IL-12 has anti-angiogenic activity and it is able to dramatically decrease tumor-supportive activities of tumor-associated macrophages. The first part of the review is devoted to immunobiology of IL-12. Signaling pathways of IL-12 as well as clinical trials of this cytokine are discussed. The second part of the review is concerned on the inherited variations in IL-12A and IL-12B genes that could modulate cancer susceptibility, and as a consequence, possess predictive, therapeutic, or prognostic significance. It is known that functional single nucleotide polymorphisms (SNPs) in IL-12A and IL-12B genes may dramatically affect on protein expression level, or alter its functions, which may lead to immune disorders, autoimmune diseases, and eventually contribute to cancer occurrence. The list of genetic polymorphisms for further investigations might include the following: IL-12B_+1188A/C (rs3212227), IL-12A_+277G/A (rs568408), IL-12A_-798T/A (rs582054), IL-12A_-504T/G (rs190533), IL-12A_-1148T/C (rs2243123), and IL-12B_+16974 A/C. Perhaps, some of these SNPs may become an attractive target for oncogenomics and possibly could be used in programs of early cancer diagnosis as well as cancer prevention in the nearest future.

IL-12 upregulates TIM-3 expression and induces T cell exhaustion in patients with follicular B cell non-Hodgkin lymphoma

The cytokine IL-12 induces IFN-γ production by T and NK cells. In preclinical models, it contributes to antitumor immunity. However, in clinical testing, it has shown limited benefit in patients with any one of a variety of malignancies. Moreover, in a clinical trial testing a combination of IL-12 and rituximab in patients with follicular B cell non-Hodgkin lymphoma (FL), those treated with IL-12 showed a lower response rate, suggesting that IL-12 actually plays a detrimental role. Here, we investigated whether the failure of IL-12 treatment for FL was due to T cell exhaustion, a condition characterized by reduced T cell differentiation, proliferation, and function, which has been observed in chronic viral infection. We found that extended exposure to IL-12 induced T cell exhaustion and contributed to the poor prognosis in FL patients. Long-term exposure of freshly isolated human CD4+ T cells to IL-12 in vitro caused T cell dysfunction and induced expression of TIM-3, a T cell immunoglobulin and mucin domain protein with a known role in T cell exhaustion, via an IFN-γ-independent mechanism. TIM-3 was required for the negative effect of IL-12 on T cell function. Importantly, TIM-3 also was highly expressed on intratumoral T cells that displayed marked functional impairment. Our findings identify IL-12- and TIM-3-mediated exhaustion of T cells as a mechanism for poor clinical outcome when IL-12 is administered to FL patients.

Soluble IL-2Rα facilitates IL-2-mediated immune responses and predicts reduced survival in follicular B-cell non-Hodgkin lymphoma

Elevated serum levels of the soluble form of IL-2 receptor α (sIL-2Rα) have been correlated with a poor prognosis in a variety of different types of cancers. However, its biologic relevance remains unclear and controversial. In patients with follicular B-cell non-Hodgkin lymphoma (FL), we observed that serum sIL-2Rα levels were elevated compared with controls and that elevated sIL-2Rα levels before treatment were associated with a poor outcome. To explore the mechanism by which sIL-2Rα may contribute to a poor prognosis in FL, we determined the effects of sIL-2Rα on IL-2 signaling and found that the sIL-2Rα-IL-2 complex promoted T-cell differentiation toward to inhibitory T(reg) cells rather than T(H)1 or T(H)17 cells. Shed by activated T cells that express membrane-bound IL-2Rα, sIL-2Rα further enhanced IL-2-mediated phosphorylation of Stat5 thereby significantly up-regulating Foxp3 expression in CD4(+) T cells. We found that CD4(+) T cells treated with either IL-2 or sIL-2Rα-IL-2 complex, but not with sIL-2Rα alone, inhibited the function of CD8(+) T cells. Taken together, these results indicate that sIL-2Rα actually plays an active biologic role in FL by binding IL-2 and promoting IL-2 signaling rather than depleting IL-2 and blocking its function.

Household contact with pets and birds and risk of lymphoma

BACKGROUND

Contact with household pets has been suggested to be inversely associated with lymphoma risk.

METHODS

We tested the hypothesis in a case-control study of lymphoma in the Sardinia region of Italy. Cases were 326 patients, first diagnosed with lymphoma in 1999-2003. Controls were 464 population controls, frequency matched to cases by age, gender, and area of residence. In person interviews included self-reported household contact with pets and birds, type of pet(s), and age at starting contact.

RESULTS

Frequent contact with birds was inversely associated with lymphoma, and particularly B-cell non-Hodgkin lymphoma (odds ratio [OR] = 0.6, 95% confidence interval [95% CI]: 0.4, 0.9). Contact with chickens accounted for this inverse association, which was strongest for first contact occurring at age ≤8 years (OR = 0.4, 95% CI: 0.2, 1.0). No association was observed when first contact occurred at age 9 or older. Contact with any pets was inversely associated with risk of diffuse large B-cell lymphoma (OR = 0.4, 95% CI: 0.2, 1.0), but not other lymphoma subtypes.

CONCLUSION

Our results support the hypothesis that early-life exposure to pets, birds and particularly with chickens might be associated with a reduced risk of lymphoma.

Interleukin-4 distinctively modifies responses of germinal centre-like and activated B-cell-like diffuse large B-cell lymphomas to immuno-chemotherapy

Diffuse large B-cell lymphomas (DLBCLs) can be classified into two subtypes: germinal-centre B-cell (GCB)-like and Activated B-cell (ABC)-like tumours, which are associated with longer or shorter patient overall survival, respectively. In our previous studies, we have shown that, although DLBCL tumours of GCB-like and ABC-like subtypes express similar levels of IL4 mRNA, they exhibit distinct patterns of IL-4-induced intracellular signalling and different expression of IL-4 target genes. We hypothesized that these differences may contribute to the different clinical behaviour and outcome of DLBCL subtypes. Herein, we demonstrated that IL-4 increased the sensitivity of GCB-like DLBCL to doxorubicin-induced apoptosis and complement-dependent rituximab cell killing. In contrast, IL-4 protected ABC-like DLBCL from the cytotoxic effects of doxorubicin and rituximab. The distinct effects of IL-4 on doxorubicin sensitivity in GCB-like and ABC-like DLBCL cells may be partially attributed to the contrasting effects of the cytokine on Bcl-2 and Bad protein levels in the DLBCL subtypes. These findings suggest that the different effects of IL-4 on chemotherapy and immunotherapy-induced cytotoxicity of GCB- and ABC-like DLBCL could contribute to the different clinical outcomes exhibited by patients with these two subtypes of DLBCL.

IL-4 protects the B-cell lymphoma cell line CH31 from anti-IgM-induced growth arrest and apoptosis: contribution of the PI-3 kinase/AKT pathway

Interleukin-4 (IL-4) promotes lymphocyte survival and protects primary lymphomas from apoptosis. Previous studies reported differential requirements for the signal transducer and activator of transcription 6 (STAT6) and IRS2/phosphatidylinositol 3 kinase (PI-3K) signaling pathways in mediating the IL-4-induced protection from Fas-mediated apoptosis. In this study, we characterized IL-4-activated signals that suppress anti-IgM-mediated apoptosis and growth arrest of CH31, a model B-cell lymphoma line. In CH31, anti-IgM treatment leads to the loss of mitochondrial membrane potential, phospho-Akt, phospho-CDK2, and c-myc protein. These losses are followed by massive induction of p27(Kip1) protein expression, cell cycle arrest, and apoptosis. Strikingly, IL-4 treatment prevented or reversed these changes. Furthermore, IL-4 suppressed the activation of caspases 9 and 3, and, in contrast to previous reports, induced the phosphorylation (deactivation) of BAD. IL-4 treatment also induced expression of BclxL, a STAT6-dependent gene. Pharmacologic inhibitors and dominant inhibitory forms of PI-3K and Akt abrogated the anti-apoptotic function of IL-4. These results suggest that the IL-4 receptor activates several signaling pathways, with the Akt pathway playing a major role in suppression of the apoptotic program activated by anti-IgM.

Role of tumor-derived proinflammatory cytokines GM-CSF, TNF-alpha, and IL-12 in the migration and differentiation of antigen-presenting cells in cervical carcinoma

BACKGROUND

Proinflammatory cytokines are important in modifying the activity, differentiation, and migration of antigen-presenting cells and may influence the survival of cancer patients. The study assessed whether GM-CSF, TNF-alpha, and IL-12, produced by cervical cancer cells, are important for the activity, differentiation, and migration of antigen-presenting cells.

METHODS

In 90 patients with cervical carcinoma the number of monocytes/tumor-associated macrophages (TAM), mature dendritic cells (DC), and Langerhans cells (LHC) was determined using immunohistochemistry. An RNA in situ hybridization technique was used to measure the expression level of GM-CSF, TNF-alpha, IL-12p35, and IL-12p40.

RESULTS

TAM were detected intraepithelial as well as in the stroma of the tumor. LHC were only detected intraepithelial and mature DC only in the tumor stroma. The number of TAM correlated positively with the number of mature DC. The expression levels of GM-CSF and TNF-alpha correlated positively with the number of TAM and DC. TNF-alpha showed a negative correlation with the number of LHC. A significant correlation between the expression of functional IL-12 (IL-12p40) and stromal TAM was found. The expression of GM-CSF, TNF-alpha, and IL-12p40 did not correlate significantly with disease-free survival. However, high IL-12p40 expression was associated with a favorable cumulative overall survival.

CONCLUSIONS

The results suggest that GM-CSF as well as TNF-alpha, produced by cervical carcinoma cells, may play a role in the differentiation of monocytes into mature DC. Furthermore, TNF-alpha may influence the migration of LHC from the tumor.

Expansion of Vdelta1 T lymphocytes producing IL-4 in low-grade non-Hodgkin lymphomas expressing UL-16-binding proteins

Data on 23 patients with low-grade non-Hodgkin lymphomas (NHLs), 4 mantle (MT), 4 marginal zone (MZ), and 15 follicular (FL), were analyzed and compared with 10 high-risk (HR) B-cell chronic lymphocytic leukemias (B-CLLs) with lymph node involvement and 4 diffuse large-cell lymphomas (DLCLs). A significant increase in circulating Vdelta1 T lymphocytes producing interleukin-4 (IL-4) was found in patients with FL, MT, and MZ NHL, at variance with DLCL and HR B-CLL. IL-4 was also detectable in the sera and lymph nodes of the same patients. In 19 of the 23 patients with NHL with increased circulating Vdelta1 T lymphocytes, B cells expressing the UL-16-binding proteins (ULBPs) ULBP2 or ULBP3 or both were found in peripheral blood, bone marrow, or lymph nodes. Of note, in HR B-CLL or in DLCL, where leukemic cells were negative for ULBPs, no Vdelta1 T-cell increase was found. Moreover, Vdelta1 T lymphocytes from patients with FL NHL proliferate in response to ULBP2+ and ULBP3+ lymphoma cells. Finally, patients with high expression of ULBPs, increased circulating Vdelta1 T lymphocytes, and high levels of serum IL-4 showed stable disease in a 1-year follow-up in contrast to patients with low circulating Vdelta1 T cells and undetectable IL-4 or ULBPs.

Effect of granulocyte colony-stimulating factor on IL-12 p40 production during chemotherapy for B-cell lineage non-Hodgkin's lymphoma patients

Interleukin (IL)-12 is a 70-kDa cytokine comprised of two disulfide-linked proteins (p35 and p40) and is essential for the initiation of effective immune response. Granulocyte-colony stimulating factor (G-CSF) affects the balance in the production of anti-inflammatory cytokines. We investigated the serum IL-12 p40 and IL-12 Mix (p40 and p70) production in 28 patients with B-cell lineage non-Hodgkin's lymphoma (NHL) treated with chemotherapy (e.g., CHOP regimen) with or without G-CSF administration and eight healthy volunteers. We found that serum levels of IL-12 p40 (191.2 +/- 150.0 pg/mL) and IL-12 Mix (277.4 +/- 274.5 pg/mL) in the patients before chemotherapy were higher than those in the healthy volunteers (IL-12 p40: 76.4 +/- 25.3 pg/mL, IL-12 Mix: 48.5 +/- 33.4 pg/mL) (P = 0.04 and 0.02, respectively). Next, we examined the serum IL-12 p40 and IL-12 Mix levels in nine patients receiving chemotherapy with administration of G-CSF (CG group, n = 9) and without G-CSF (C group, n = 9). Serum IL-12 p40 and IL-12 Mix levels were decreased on 10 d after chemotherapy in both groups, and those in CG groups were significantly lower than those in C group. These results indicated that administration of G-CSF decreased serum IL-12 p40 and IL-12 Mix levels. Overall survival (OS) at 24 months was not significantly different in the two groups (58.3% in group C vs. 80.0% in group CG, P = 0.67). However, the survival rate of patients at clinical stages III and IV in CG group (n = 6, 66.0%) was significantly better than that of patients in C group (n = 4, 25.0%) (P = 0.02). Long-term administration of G-CSF appears to influence the survival rate by reducing immunosuppressive IL-12 p40 production.

Tumor-infiltrating cells as a prognostic factor in Hodgkin's lymphoma: a quantitative tissue microarray study in a large retrospective cohort of 267 patients

The present study aimed to describe the general tissular composition of the immune infiltrate observed in Hodgkin's lymphoma (HL) and its possible relationship with clinical and survival prognostic factors. In this retrospective study of 267 HL patients, the relative proportions of infiltrating T lymphocytes (CD4+, CD8+), natural killer cells (CD 56+, CD 57+), cytotoxic cells (Granzyme B+, TIA-1+) and dendritic cells (CD 21+, S-100+) were quantified immunohistochemically with tissue microarray technology. Our results confirm the predominance of CD4 + T lymphocytes in the background of tumoral cells, in addition to a high number of cytotoxic lymphocytes (CD8, CD 57 and TIA-1). Patients with low numbers of infiltrating CD8, CD 56, CD 57+cells and high numbers of Granzyme B and TIA-1+cells presented a significantly unfavourable clinical course (presence of leukocytosis, B symptoms, advanced clinical stage (III/IV), non-responding patients). A reduced infiltration of CD4+T lymphocytes was related with the presence of Epstein - Barr virus. Significantly longer survival times were observed in patients with a high level of infiltrating CD 57, as well as a low level of Granzyme B and TIA-1+cells (log-rank test). When evaluated in a multivariate model, high levels of infiltrating TIA-1 and Granzyme B+cells were shown to be independent prognostic factors that negatively influenced overall survival. The presence of TIA-1+cells was found to be the only unfavorable prognostic factor of event-free survival and disease-free survival. The overall detection of tumor-infiltrating cells in HL confirms the importance of cytotoxic T lymphocyte infiltration (Granzyme B and TIA-1+cells) in these patients. Independently of the classical clinical and pathological features, these cells appear to be an unfavourable prognostic factor in HL and, more particularly, the presence of cytotoxic TIA-1+cells.

Peripheral T cells of patients with B cell non-Hodgkin's lymphoma show a shift in their memory status

BACKGROUND

Tumor-infiltrating T cells have a positive influence on the clinical course of B cell non-Hodgkin's lymphoma (NHL). T cells in the peripheral blood of patients with B cell NHL, however, have so far rarely been examined.

METHODS

Using flow cytometry we examined lymphocyte subpopulations and numbers of naïve/memory T cell subtypes among peripheral T cells of patients with B cell NHL (N=22), patients with metastasized solid tumors (N=27), and healthy controls (N=20). In addition, we analyzed the intracellular content of effector molecules granzyme B and perforin and expression of the T cell receptor zeta chain.

RESULTS

We observed increased percentages of potentially highly cytotoxic CD8+CD56+ T cells in the peripheral blood of patients with NHL. Both, patients with NHL and patients with solid tumors showed a much higher expression of the chemokine receptors CCR4 and CCR5 on their T cells than healthy controls, suggesting a polarization of their T cells following stimulation with antigen and/or cytokines in vivo. Furthermore, patients with B cell NHL and patients with solid tumors had far lower percentages of naïve CD45RA+CCR7+ T cells than healthy controls and, in the case of CD4+ T cells, patients with solid tumors. In contrast, patients with B cell NHL showed markedly increased levels of memory effector CD45RA-CCR7- CD4(+) T cells when compared to healthy controls and patients with metastasized solid tumors. Patients with NHL also showed elevated levels granzyme B within CD8(+) T cells, indicating that the increase in memory effector cells was of functional relevance.

CONCLUSIONS

These findings indicate a marked shift in the composition of peripheral T cells of patients with B cell NHL from naïve to memory effector-type cells.

Distinct IL-4-induced gene expression, proliferation, and intracellular signaling in germinal center B-cell-like and activated B-cell-like diffuse large-cell lymphomas

Diffuse large B-cell lymphomas (DLBCLs) can be subclassified into germinal center B-cell (GCB)-like and activated B-cell (ABC)-like tumors characterized by long and short survival, respectively. In contrast to ABC-like DLBCL, GCB-like tumors exhibit high expression of components of the interleukin 4 (IL-4) signaling pathway and of IL-4 target genes such as BCL6 and HGAL, whose high expression independently predicts better survival. These observations suggest distinct activity of the IL-4 signaling pathway in DLBCL subtypes. Herein, we demonstrate similar IL-4 expression but qualitatively different IL-4 effects on GCB-like and ABC-like DLBCL. In GCB-like DLBCL, IL-4 induces expression of its target genes, activates signal transducers and activators of transcription 6 (STAT6) signaling, and increases cell proliferation. In contrast, in the ABC-like DLBCL, IL-4 activates AKT, decreases cell proliferation by cell cycle arrest, and does not induce gene expression due to aberrant Janus kinase (JAK)-STAT6 signaling attributed to STAT6 dephosphorylation. We found distinct expression profiles of tyrosine phosphatases in DLBCL subtypes and identified putative STAT6 tyrosine phosphatases-protein tyrosine phosphatase nonreceptor type 1 (PTPN1) and PTPN2, whose expression is significantly higher in ABC-like DLBCL. These differences in tyrosine phosphatase expression might underlie distinct expression profiles of some of the IL-4 target genes and could contribute to a different clinical outcome of patients with GCB-like and ABC-like DLBCLs.

Functional analysis of -571 IL-10 promoter polymorphism reveals a repressor element controlled by sp1

Transcriptional dysregulation of the IL-10 gene may contribute to the development and severity of autoimmune, infectious, neoplastic, and allergic diseases. A C to A base substitution has been identified at -571 bp in the IL-10 promoter and has been linked to immune diseases. The role of this polymorphism in IL-10 promoter function was assessed using luciferase reporter constructs. The presence of an A at -571 (A allele) increases promoter activity compared with that of a promoter with a C at this position (C allele). Binding of nuclear extract proteins from IL-10-producing human cell lines to DNA sequences including this base exchange and flanking sequences was demonstrated using EMSAs. Specific binding of the transcription factors Sp1 and Sp3 was demonstrated to a region immediately upstream of the polymorphism. No differences in the binding affinity of recombinant Sp1 were observed between the two forms of the promoter. Reconstitution of Sp1 expression decreased IL-10 promoter function in an Sp1-deficient cell line, demonstrating that this element functions as a repressor. The C to A base exchange relieves the repression mediated by Sp1. Individuals carrying the A allele of the IL-10 promoter may display increased synthesis of IL-10, resulting in suppressed immune responses and a modulation of their susceptibility to autoimmune, infectious, neoplastic, or atopic disease.

Autologous lymphoma vaccines induce human T cell responses against multiple, unique epitopes

The clonotypic surface Ig receptor expressed by malignant B cells, idiotype, is a tumor-specific antigen and an attractive target for active immunotherapy. While Ab's specific for tumor idiotype have been well described in patients with B cell malignancies, the precise antigenic epitopes in human idiotype recognized by autologous T cells remain largely unknown. We report here that T cell lines generated from lymphoma patients actively immunized with idiotype protein specifically recognized multiple, unique immunodominant epitopes in autologous tumor idiotype. Synthetic peptides corresponding to hypervariable, but not framework, regions of Ig heavy chain specifically stimulated CD4(+) and CD8(+) T cells to proliferate and secrete proinflammatory cytokines in an MHC-associated manner. Detailed analysis revealed a minimal determinant of an immunodominant epitope, comprising critical residues at the amino terminus that may be a product of somatic hypermutation. Association of idiotype-specific T cell responses with previously documented molecular remissions in idiotype-vaccinated patients suggests that the newly identified T cell epitopes may be clinically relevant. Such antigenic epitopes may serve as candidates for novel peptide-vaccine strategies, and as tools to selectively expand tumor antigen-specific T cells for adoptive immunotherapy and for monitoring T cell immunity in vaccinated patients.

Intracellular IL-4/IFN-gamma producing peripheral T lymphocyte subsets in B cell non-Hodgkin's lymphoma patients

AIM

The availability of several biological therapy options is rapidly growing in the field of malignant lymphomas. This emphasizes the need to understand the precise interaction of the host immune system with the malignant disease. We measured the intracellular cytokine responses in lymphoma patients' lymphocytes, to characterize the polarization changes in their immune system.

METHODS

Patients with B cell non-Hodgkin's lymphoma were involved in the study. Peripheral lymphocytes were labeled with anti-CD4 or anti-CD8 antibodies and intracellular accumulation of IL-4 or IFN-gamma was detected after in vitro incubation the cells with activating cocktail. The frequency of different T-cell subsets were measured within the lymphocyte population.

RESULTS

Significantly increased CD4+, IFN-gamma producing (Th1) cell percentage were found in untreated lymphoma cases (28.8% vs. 21.8%). CD8+ IL-4 and IFN-gamma producing (Tc0) T cell frequency is significantly higher in untreated lymphoma patients compared with normal controls (1.3% vs. 0.47%). The frequency of CD4+ IL-4 producing (Th2) cells is significantly lower in untreated patients (0.96% vs. 1.19%). Patients in long-term remission have lower frequency of CD4+, IL4 producing (Th2) cell ratio (0.31% vs. 1.19%) and increased CD4+ IFN-gamma producing (Th1) cell frequency (30.1% vs. 21.8%), compared with healthy normal controls.

CONCLUSION

Our results demonstrate that there is a sustained increase in the CD4+ IFN-gamma producing cell frequency in lymphoma patients. The frequency of CD4+ IL-4 producing cells is decreasing by treatment. These may contribute to strong polarization toward Th1 type response, needed for lymphoma clearance and remission.

Tyrosine phosphorylation in human lymphomas

In a previous study, we showed that the high level of protein tyrosine phosphorylation present in lymphomas containing an anaplastic lymphoma kinase (ALK) can be demonstrated in routinely processed paraffin tissue sections using immunolabelling techniques. In the present study we investigated whether oncogenic tyrosine kinase activation also occurs in other categories of lymphoma by staining 145 cases of lymphoma covering those tumours with a range of different subtypes including those with morphological similarity to ALK-positive anaplastic large cell lymphoma (ALCL). Twelve cases of the borderline malignant disorder lymphomatoid papulosis were also studied. Twenty seven of the 28 cases of ALK-positive ALCL showed the extensive cytoplasmic labelling for phosphotyrosine in the neoplastic cells. The remaining case containing moesin-ALK exhibited membrane-associated phosphotyrosine expression. There was no nuclear phosphotyrosine labelling in any of the ALK-positive ALCL, even though ALK was present within the cell nuclei in 23 of the tumours. Variable degrees of phosphotyrosine labelling, usually membrane-restricted, were observed in 7/40 cases of ALK-negative ALCL, 9/29 cases of diffuse large B-cell lymphoma, 3/6 cases of mediastinal B-cell lymphoma, 2/7 cases of Hodgkin's lymphoma, 3/6 cases of peripheral T-cell lymphomas unspecified, 4/6 cases of B-cell chronic lymphocytic leukaemia, 2/6 cases of follicular lymphomas and 2/12 cases of lymphomatoid papulosis studied. However none of these phosphotyrosine-positive cases showed the strong cytoplasmic labelling comparable to that seen in ALK-positive lymphoma. We conclude that activation of a tyrosine kinase is probably not a major oncogenic event in lymphomas other than ALK-positive ALCL.

HGAL is a novel interleukin-4-inducible gene that strongly predicts survival in diffuse large B-cell lymphoma

We have cloned and characterized a novel human gene, HGAL (human germinal center-associated lymphoma), which predicts outcome in patients with diffuse large B-cell lymphoma (DLBCL). The HGAL gene comprises 6 exons and encodes a cytoplasmic protein of 178 amino acids that contains an immunoreceptor tyrosine-based activation motif (ITAM). It is highly expressed in germinal center (GC) lymphocytes and GC-derived lymphomas and is homologous to the mouse GC-specific gene M17. Expression of the HGAL gene is specifically induced in B cells by interleukin-4 (IL-4). Patients with DLBCL expressing high levels of HGAL mRNA demonstrate significantly longer overall survival than do patients with low HGAL expression. This association was independent of the clinical international prognostic index. High HGAL mRNA expression should be used as a prognostic factor in DLBCL.