B-cell depletion using an anti-CD20 antibody augments antitumor immune responses and immunotherapy in nonhematopoetic murine tumor models

A Rare Presentation of Collision Diffuse Large B-Cell Lymphoma and Hodgkin Lymphoma Treated with R-CHOP and Adjuvant Radiation Therapy

Collision tumors are rare neoplasms displaying two distinct cell populations developing in juxtaposition to one another without areas of intermingling. There are currently no guidelines for the recommended treatment for such rare collision cases. We herein report a unique case of a 45-year-old female who presented with a left-sided palpable inguinal lymph node. A subsequent excisional biopsy yielded a diagnosis of collision lymphoma (CL) of nodular sclerosing Hodgkin lymphoma (HL) and germinal center diffuse large B-cell lymphoma (DLBCL). This case report highlights the challenges in managing CL and the potential efficacy of cyclophosphamide, doxorubicin, vincristine, prednisone, and rituximab regimen (R-CHOP) and adjuvant radiation therapy (RT) in treating this rare condition. Our goal is to enrich the literature with our case on CL in an attempt to progress to a path of ultimately establishing a definitive treatment approach to CL of DLBCL and HL.

Immune microenvironment of cervical cancer and the role of IL-2 in tumor promotion

The tumor microenvironment (TME) is a heterogeneous mixture of resident and tumor cells that maintain close communication through their secretion products. The composition of the TME is dynamic and complex among the different types of cancer, where the immune cells play a relevant role in the elimination of tumor cells, however, under certain circumstances they contribute to tumor development. In cervical cancer (CC) the human papilloma virus (HPV) shapes the microenvironment in order to mediate persistent infections that favors transformation and tumor development. Interleukin-2 (IL-2) is an important TME cytokine that induces CD8+ effector T cells and NKs to eliminate tumor cells, however, IL-2 can also suppress the immune response through Treg cells. Recent studies have shown that CC cells express the IL-2 receptor (IL-2R), that are induced to proliferate at low concentrations of exogenous IL-2 through alterations in the JAK/STAT pathway. This review provides an overview of the main immune cells that make up the TME in CC, as well as the participation of IL-2 in the tumor promotion. Finally, it is proposed that the low density of IL-2 produced by immunocompetent cells is used by tumor cells through its IL-2R as a mechanism to proliferate simultaneously depleting this molecule in order to evade immune response.

Classical Hodgkin Lymphoma: From Past to Future-A Comprehensive Review of Pathophysiology and Therapeutic Advances

Hodgkin lymphoma, a hematological malignancy of lymphoid origin that typically arises from germinal-center B cells, has an excellent overall prognosis. However, the treatment of patients who relapse or develop resistant disease still poses a substantial clinical and research challenge, even though current risk-adapted and response-based treatment techniques produce overall survival rates of over 95%. The appearance of late malignancies after the successful cure of primary or relapsed disease continues to be a major concern, mostly because of high survival rates. Particularly in pediatric HL patients, the chance of developing secondary leukemia is manifold compared to that in the general pediatric population, and the prognosis for patients with secondary leukemia is much worse than that for patients with other hematological malignancies. Therefore, it is crucial to develop clinically useful biomarkers to stratify patients according to their risk of late malignancies and determine which require intense treatment regimens to maintain the ideal balance between maximizing survival rates and avoiding late consequences. In this article, we review HL's epidemiology, risk factors, staging, molecular and genetic biomarkers, and treatments for children and adults, as well as treatment-related adverse events and the late development of secondary malignancies in patients with the disease.

Role of lymphocytes, macrophages and immune receptors in suppression of tumor immunity

Cancer is now the leading cause of mortality across the world. Inflammatory immune cells are functionally important in the genesis and progression of tumors, as demonstrated by their presence in human tumors. Numerous research has recently been conducted to determine if the innate and adaptive immune systems' cytotoxic cells can inhibit tumor growth and spread. Majority of cancers, when growing into identifiable tumors use multiple strategies to elude immune monitoring by lowering tumor immunity. Immunological suppression in the tumor microenvironment is achieved through interfering with antigen-presenting cells and effector T cells. Treatment of cancer requires managing both the tumor as well as tumor microenvironment (TME). Most patients will not be able to gain benefits from immunotherapy because of the immunosuppressive tumor microenvironment. The actions of many stromal myeloid and lymphoid cells are regulated to suppress tumor-specific T lymphocytes. These frequently exhibit inducible suppressive processes brought on by the same anti-tumor inflammatory response the immunotherapy aims to produce. Therefore, a deeper comprehensive understanding of how the immunosuppressive environment arises and endures is essential. Here in this chapter, we will talk about how immune cells, particularly macrophages and lymphocytes, and their receptors affect the ability of tumors to mount an immune response.

Clinical relevance and therapeutic aspects of professional antigen-presenting cells in lung cancer

Lung cancer stays the preeminent cause of death worldwide. Despite recent advancements in chemotherapy, radiotherapy, and immunotherapy, the survival rate for people with advanced stages of the disease is still appalling. Moreover, there is a severe lack of reliable prognoses and indicators for classification in newly developed immunotherapies. A better understanding of immune cells is necessary to harness immune response mechanisms for therapeutic effects. Professional antigen-presenting cells are responsible for determining the fate of the immune response through the antigen processing and presentation pathway (APP). The most professional antigen-presenting cells (APC) include the dendritic cells (DC), macrophages, and B cells, which present antigens to the T-helper cells. Dendritic cells are significantly explored as a tool for immunotherapy owing to their precise ability to provoke and alter T-cell responses. Moreover, the role of tumor-associated macrophages (TAMs), an abundant leukocyte in lung cancer, is also a potential target for adjuvant anti-cancer therapies. In this review, we summarize the recent advances in our understanding of the various types of immunotherapy mapped out via professional antigen-presenting cells in lung cancer.

Neutrophils: Musketeers against immunotherapy

Neutrophils, the most copious leukocytes in human blood, play a critical role in tumorigenesis, cancer progression, and immune suppression. Recently, neutrophils have attracted the attention of researchers, immunologists, and oncologists because of their potential role in orchestrating immune evasion in human diseases including cancer, which has led to a hot debate redefining the contribution of neutrophils in tumor progression and immunity. To make this debate fruitful, this review seeks to provide a recent update about the contribution of neutrophils in immune suppression and tumor progression. Here, we first described the molecular pathways through which neutrophils aid in cancer progression and orchestrate immune suppression/evasion. Later, we summarized the underlying molecular mechanisms of neutrophil-mediated therapy resistance and highlighted various approaches through which neutrophil antagonism may heighten the efficacy of the immune checkpoint blockade therapy. Finally, we have highlighted several unsolved questions and hope that answering these questions will provide a new avenue toward immunotherapy revolution.

Combination of Atezolizumab and Obinutuzumab in Patients with Relapsed/Refractory Follicular Lymphoma and Diffuse Large B-Cell Lymphoma: Results from a Phase 1b Study

BACKGROUND

This was an open-label, phase 1b study assessing the safety, tolerability, preliminary efficacy and pharmacokinetics of the combination of atezolizumab and obinutuzumab in patients with relapsed/refractory follicular lymphoma (FL) or diffuse large B-cell lymphoma (DLBCL). There is a mechanistic rationale suggesting that this combination may enhance recruitment of both innate and adaptive immunity and be effective against CD20+ B-cell malignancies.

MATERIALS AND METHODS

The study consisted of a safety evaluation stage and an expansion stage. Patients received obinutuzumab 1000 mg intravenously (IV) in cycle (C) 1, obinutuzumab plus atezolizumab 1200 mg IV for C2-8, and atezolizumab only from C9. Primary endpoints were to identify a recommended phase 2 dose (RP2D) for atezolizumab, and safety and tolerability in the safety and expansion stages.

RESULTS

A total of 49 patients were enrolled (FL, n = 26; DLBCL, n = 23), with a median of 2 prior lines of treatment. The RP2D for atezolizumab was 1200 mg IV every 3 weeks. Adverse events reported in ≥ 20% of patients were fatigue (15 patients [31%]), nausea (13 patients [27%]), cough, and diarrhea (10 patients [20%] each). Objective response rate was 54% in the FL cohort (complete response [CR] rate: 23%) and 17% in the DLBCL cohort (CR: 4%). Median progression-free survival was 9 months for FL and 3 months for DLBCL. Median overall survival was not estimable for FL and 9 months for DLBCL.

CONCLUSION

The combination of obinutuzumab and atezolizumab was determined to be safe and tolerable, with no new toxicities observed.

B-Lymphocytes in the Pathophysiology of Pancreatic Adenocarcinoma

Pancreatic adenocarcinoma is highly infiltrated by B lymphocytes but the relevance of these immune cells in tumor development has been surprisingly overlooked until recently. Based on available evidence from other solid tumors, interaction between B lymphocytes and neoplastic cells is probably not uniformly stimulatory or inhibitory. Although presentation of tumor antigens to T cells and production of antitumor immunoglobulins might intuitively suggest a prominent tumor suppressive activity, specific subsets of B lymphocytes can secrete growth factors for neoplastic cells and immunosuppressive cytokines thus promoting escape from immunosurveillance and cancer progression. Because many of these mechanisms might also be implicated in the development of PDAC, and immune-modulation of B-cell activity is nowadays possible at different levels, determining the role of B-lymphocytes in this lethal cancer becomes of utmost importance to design novel therapeutic strategies. This review aims to discuss the emerging role of B cells in PDAC tumorigenesis, progression, and associated stromal reaction.

Mathematical modeling of tumor-immune system interactions: the effect of rituximab on breast cancer immune response

tBregs are a newly discovered subcategory of B regulatory cells, which are generated by breast cancer, resulting in the increase of Tregs and therefore in the death of NK cells. In this study, we use a mathematical and computational approach to investigate the complex interactions between the aforementioned cells as well as CD8⁺ T cells, CD4⁺ T cells and B cells. Furthermore, we use data fitting to prove that the functional response regarding the lysis of breast cancer cells by NK cells has a ratio-dependent form. Additionally, we include in our model the concentration of rituximab - a monoclonal antibody that has been suggested as a potential breast cancer therapy - and test its effect, when the standard, as well as experimental dosages, are administered.

The dual role of neutrophils in cancer

For the past decade, the role and importance of neutrophils in cancer is being increasingly appreciated. Research has focused on the ability of cancer-related neutrophils to either support tumor growth or interfere with it, showing diverse mechanisms through which the effects of neutrophils take place. In contrast to the historic view of neutrophils as terminally differentiated cells, mounting evidence has demonstrated that neutrophils are a plastic and diverse population of cells. These dynamic and plastic abilities allow them to perform varied and sometimes opposite functions simultaneously. In this review, we summarize and detail clinical and experimental evidence for, and underlying mechanisms of, the dual impact of neutrophils' functions, both supporting and inhibiting cancer development. We first discuss the effects of various basic functions of neutrophils, namely direct cytotoxicity, secretion of reactive oxygen species (ROS), nitric oxide (NO) and proteases, NETosis, autophagy and modulation of other immune cells, on tumor growth and metastatic progression. We then describe the clinical evidence for pro- vs anti-tumor functions of neutrophils in human cancer. We believe and show that the "net" impact of neutrophils in cancer is the sum of a complex balance between contradicting effects which occur simultaneously.

Immunosuppressive Mechanisms of Regulatory B Cells

Regulatory B cells (Bregs) is a term that encompasses all B cells that act to suppress immune responses. Bregs contribute to the maintenance of tolerance, limiting ongoing immune responses and reestablishing immune homeostasis. The important role of Bregs in restraining the pathology associated with exacerbated inflammatory responses in autoimmunity and graft rejection has been consistently demonstrated, while more recent studies have suggested a role for this population in other immune-related conditions, such as infections, allergy, cancer, and chronic metabolic diseases. Initial studies identified IL-10 as the hallmark of Breg function; nevertheless, the past decade has seen the discovery of other molecules utilized by human and murine B cells to regulate immune responses. This new arsenal includes other anti-inflammatory cytokines such IL-35 and TGF-β, as well as cell surface proteins like CD1d and PD-L1. In this review, we examine the main suppressive mechanisms employed by these novel Breg populations. We also discuss recent evidence that helps to unravel previously unknown aspects of the phenotype, development, activation, and function of IL-10-producing Bregs, incorporating an overview on those questions that remain obscure.

Atlas of breast cancer infiltrated B-lymphocytes revealed by paired single-cell RNA-sequencing and antigen receptor profiling

To gain mechanistic insights into the functions and developmental dynamics of tumor-infiltrated immune cells, especially B-lymphocytes, here we combine single-cell RNA-sequencing and antigen receptor lineage analysis to characterize a large number of triple-negative breast cancer infiltrated immune cells and report a comprehensive atlas of tumor-infiltrated B-lymphocytes. The single-cell transcriptional profiles reveal significant heterogeneity in tumor-infiltrated B-cell subgroups. The single-cell antigen receptor analyses demonstrate that compared with those in peripheral blood, tumor-infiltrated B-cells have more mature and memory B-cell characteristics, higher clonality, more class switching recombination and somatic hypermutations. Combined analyses suggest local differentiation of infiltrated memory B-cells within breast tumors. The B-cell signatures based on the single-cell RNA-sequencing results are significantly associated with improved survival in breast tumor patients. Functional analyses of tumor-infiltrated B-cell populations suggest that mechanistically, B-cell subgroups may contribute to immunosurveillance through various pathways. Further dissection of tumor-infiltrated B-cell populations will provide valuable clues for tumor immunotherapy.

Immune cells infiltrating the tumour microenvironment play critical roles in disease pathogenesis and the immune response. Here the authors present the characterisation of infiltrating B cells in breast tumours by the formation of an atlas created from paired RNA sequence and antigen receptor profiling.

Identification of an immune-related six-long noncoding RNA signature as a novel prognosis biomarker for adenocarcinoma of lung

BACKGROUND

Lung adenocarcinoma (LUAD) is a heterogeneous disease with high mortality. Close attention has been paid to immunotherapy in LUAD treatment. However, immunotherapy has produced different therapeutic effects because of immune heterogeneity. Long noncoding RNAs (lncRNAs) are survival prognostic indicators with functions in the immune process. The present study was designed to examine the predictive power of immune-related lncRNAs in LUAD prognosis and investigated potential molecular mechanisms.

METHODS

Transcriptome profiling and LUAD sample clinical information were retrieved from online database. The immune-related lncRNAs signature was identified by Cox regression. Survival analysis was used to verify the validity of the prognosis model. Then, possible biological functions were predicted and the abundance of infiltrating immune cells in LUAD samples were further analyzed.

RESULTS

An immune-associated lncRNAs signature was established by combining six lncRNAs. Patients with LUAD were stratified into high- and low-risk groups using the six lncRNAs signature. Patients in different risk levels had significantly different prognoses (P<0.001), and the immune-associated lncRNAs signature was identified as an independent prognostic factor for LUAD. The functions of the lncRNA signature were confirmed as ubiquitin mediated proteolysis and signal sequence binding. The lncRNA signature negatively correlates with B-cell immune infiltration.

CONCLUSION

A reliable immune-related lncRNAs prognosis model for LUAD was identified. lncRNAs played a vital role in the tumor immune process and were associated with the LUAD prognosis. Research of lncRNAs in B-cell immune infiltration could provide new insight into the immunotherapy of LUAD.

Double-edge Role of B Cells in Tumor Immunity: Potential Molecular Mechanism

B cells are a heterogeneous population, which have distinct functions of antigen presentation, activating T cells, and secreting antibodies, cytokines as well as protease. It is supposed that the balance among these B cells subpopulation (resting B cells, activated B cells, Bregs, and other differentiated B cells) will determine the ultimate role of B cells in tumor immunity. There has been increasing evidence supporting opposite roles of B cells in tumor immunity, though there are no general acceptable phenotypes for them. Recent years, a new designated subset of B cells identified as Bregs has emerged from immunosuppressive and/or regulatory functions in tumor immune responses. Therefore, transferring activated B cells would be possible to become a promising strategy against tumor via conquering the immunosuppressive status of B cells in future. Understanding the potential mechanism of double-edge role of B cells will help researchers utilize activated B cells to improve their anti-tumor response. Moreover, the molecular pathways related to B cell differentiation are involved in its tumor-promoting effect, such as NF-κB, STAT3, BTK. So, we review the molecular and signaling pathway mechanisms of B cells involved in both tumor-promoting and tumor-suppressive immunity, in order to help researchers optimize B cells to fight cancer better.

The Role of Tumor-Infiltrating B Cells in Tumor Immunity

Earlier studies on elucidating the role of lymphocytes in tumor immunity predominantly focused on T cells. However, the role of B cells in tumor immunity has increasingly received better attention in recent studies. The B cells that infiltrate tumor tissues are called tumor-infiltrating B cells (TIBs). It is found that TIBs play a multifaceted dual role in regulating tumor immunity rather than just tumor inhibition or promotion. In this article, latest research advances focusing on the relationship between TIBs and tumor complexity are reviewed, and light is shed on some novel ideas for exploiting TIBs as a possible tumor biomarker and potential therapeutic target against tumors.

B lymphocytes can be activated to act as antigen presenting cells to promote anti-tumor responses

Immune evasion by tumors includes several different mechanisms, including the inefficiency of antigen presenting cells (APCs) to trigger anti-tumor T cell responses. B lymphocytes may display a pro-tumoral role but can also be modulated to function as antigen presenting cells to T lymphocytes, capable of triggering anti-cancer immune responses. While dendritic cells, DCs, are the best APC population to activate naive T cells, DCs or their precursors, monocytes, are frequently modulated by tumors, displaying a tolerogenic phenotype in cancer patients. In patients with cervical cancer, we observed that monocyte derived DCs are tolerogenic, inhibiting allogeneic T cell activation compared to the same population obtained from patients with precursor lesions or cervicitis. In this work, we show that B lymphocytes from cervical cancer patients respond to treatment with sCD40L and IL-4 by increasing the CD80+CD86+ population, therefore potentially increasing their ability to activate T cells. To test if B lymphocytes could actually trigger anti-tumor T cell responses, we designed an experimental model where we harvested T and B lymphocytes, or dendritic cells, from tumor bearing donors, and after APC stimulation, transplanted them, together with T cells into RAG1-/- recipients, previously injected with tumor cells. We were able to show that anti-CD40 activated B lymphocytes could trigger secondary T cell responses, dependent on MHC-II expression. Moreover, we showed that dendritic cells were resistant to the anti-CD40 treatment and unable to stimulate anti-tumor responses. In summary, our results suggest that B lymphocytes may be used as a tool for immunotherapy against cancer.

Tumor-infiltrating B cells: their role and application in anti-tumor immunity in lung cancer

Evidence indicates that lung cancer development is a complex process that involves interactions between tumor cells, stromal fibroblasts, and immune cells. Tumor-infiltrating immune cells play a significant role in the promotion or inhibition of tumor growth. As an integral component of the tumor microenvironment, tumor-infiltrating B lymphocytes (TIBs) exist in all stages of cancer and play important roles in shaping tumor development. Here, we review recent clinical and preclinical studies that outline the role of TIBs in lung cancer development, assess their prognostic significance, and explore the potential benefit of B cell-based immunotherapy for lung cancer treatment.

B cells inhibit the antitumor immunity against an established murine fibrosarcoma

Despite the classic role of B cells in favoring the immune response, an inhibitory action of B lymphocytes in tumor immunity has emerged in certain studies. In methylcolanthrene-induced murine fibrosarcoma (MCC), the loss of immunogenicity and the establishment of tolerance are paralleled by systemic immune suppression and the appearance of B⁺IL-10⁺ cells in tumor-draining lymph nodes. The present study aimed to assess the role of the B⁺IL-10⁺ cell population in the immune evasion and tolerance induced by MCC through the depletion of B cells in mice at various times of tumor progression: Prior to or subsequent to tumor implantation. Tumor growth and immunological parameters were evaluated. B cell depletion prior to tumor inoculum enhanced tumor growth, initiating the onset of the tumor-induced systemic immune response; however, an increase in the T regulatory cells (Tregs) at the tumor-draining lymph node could account for tumor exacerbation. B cell depletion once the tumor was established resulted in decreased tumor growth and a delayed onset of tolerance. Additionally, B cell absence exacerbated T cell dependent-tumor rejection, reduced Tregs and increased cytotoxic CD8⁺ T cells. In vitro analysis showed a direct effect of B cells upon T cell proliferation. In conclusion, B cell depletion exerts opposite effects when performed prior to or subsequent to tumor implantation. In this initially immunogenic tumor, B cell absence would delay the establishment of immunological tolerance probably by unmasking a pre-existing antitumor response. The present findings elucidate the convenience of modulating B cells in the development of future and more effective immunotherapies against cancer.

CpG-based immunotherapy impairs antitumor activity of BRAF inhibitors in a B-cell-dependent manner

Combining immunotherapy with targeted therapy has increasingly become an appealing therapeutic paradigm for cancer treatment due to its great potential for generating durable and synergistic antitumor response. In this study, however, we unexpectedly found that two types of CpG-based tumor peptide vaccine treatments consistently negated the antitumor activity of a selective BRAF inhibitor in tumors with BRAF mutation rather than showing a synergistic antitumor effect. Our further studies demonstrated that CpG alone was sufficient to dampen BRAF inhibitor-induced antitumor responses, suggesting that the impaired antitumor activity of the BRAF inhibitor observed in mice receiving CpG-based peptide vaccine is mainly dependent upon the use of CpG. Mechanistically, CpG increased the number of circulating B cells, which produced elevated amounts of tumor necrosis factor-α (TNFα) that contributed to the increased tumor resistance to BRAF inhibitors. More importantly, B-cell depletion or TNFα neutralization can restore the antitumor effect of BRAF inhibition in mice receiving CpG treatment, indicating that TNFα-secreting B cells play an indispensable role in BRAF inhibitor resistance induced by CpG. Taken together, our results strongly suggest that precautions must be implemented when designing combinatorial approaches for cancer treatment, because distinct regimens, despite their respective therapeutic benefit as monotherapy, may together provide antagonistic clinical outcomes.

PD-L1 is a critical mediator of regulatory B cells and T cells in invasive breast cancer

Regulatory T cells (Tregs), a key mediator in regulating anti-tumor immune suppression, tumor immune escape, metastasis and relapse, are considered an important therapeutic target in immunotherapy of human cancers. In the present investigation, elevated CD19⁺ CD24⁺ CD38⁺ regulatory B cells (Bregs) were observed in PBMCs of invasive carcinoma of breast (IBCa) patients compared with that in patients with fibroadenoma (FIBma) or healthy individuals, and the positive correlation existed between Bregs and CD4⁺ CD25⁺ CD127⁻ Tregs (r = 0.316, P = 0.001). We found that PD-L1 expression was higher on Bregs in IBCa patients compared with patients with FIBma or healthy individuals (P < 0.05, respectively), and that a tight correlation exists between CD19⁺ CD24⁺ CD38⁺ PD-L1⁺ Bregs and CD19⁺ CD24⁺ CD38⁺ Bregs (r = 0.267, P = 0.007), poor TNM phases and up-regulated expression of PD-L1 on Bregs. The pattern of PD-1 expression on CD4⁺ T cells indicated that high level of PD-1^hi expressed on CD4⁺ CD25⁺ CD127⁺ effector T cells (P < 0.001). More importantly, the presence of PD-L1 on Bregs was positively correlated with Tregs (r = 0.299, P = 0.003), but negatively correlated with PD-1^hi effector T cells (r = −0.22, P = 0.031). Together, results of the present study indicated that PD-L1 is an important molecule on Bregs, mediated the generation of Tregs in IBCa.

Hypoxia-inducible factors: a central link between inflammation and cancer

The tumor immune response is in a dynamic balance between antitumor mechanisms, which serve to decrease cancer growth, and the protumor inflammatory response, which increases immune tolerance, cell survival, and proliferation. Hypoxia and expression of HIF-1α and HIF-2α are characteristic features of all solid tumors. HIF signaling serves as a major adaptive mechanism in tumor growth in a hypoxic microenvironment. HIFs represent a critical signaling node in the switch to protumorigenic inflammatory responses through recruitment of protumor immune cells and altered immune cell effector functions to suppress antitumor immune responses and promote tumor growth through direct growth-promoting cytokine production, angiogenesis, and ROS production. Modulating HIF function will be an important mechanism to dampen the tumor-promoting inflammatory response and inhibit cancer growth.

Groth B. Pro- and anti-tumour effects of B cells and antibodies in cancer: a comparison of clinical studies and preclinical models

The primary immune role of B cells is to produce antibodies, but they can also influence T cell function via antigen presentation and, in some contexts, immune regulation. Whether their roles in tumour immunity are similar to those in other chronic immune responses such as autoimmunity and chronic infection, where both pro- and anti-inflammatory roles have been described, remains controversial. Many studies have aimed to define the role of B cells in antitumor immune responses, but despite this considerable body of work, it is not yet possible to predict how they will affect immunity to any given tumour. In many human cancers, the presence of tumour-infiltrating B cells and tumour-reactive antibodies correlates with extended patient survival, and this clinical observation is supported by data from some animal models. On the other hand, T cell responses can be adversely affected by B cell production of immunoregulatory cytokines, a phenomenon that has been demonstrated in humans and in animal models. The isotype and concentration of tumour-reactive antibodies may also influence tumour progression. Recruitment of B cells into tumours may directly reflect the subtype and strength of the anti-tumour T cell response. As the response becomes chronic, B cells may attenuate T cell responses in an attempt to decrease host damage, similar to their described role in chronic infection and autoimmunity. Understanding how B cell responses in cancer are related to the effectiveness of the overall anti-tumour response is likely to aid in the development of new therapeutic interventions against cancer.

The double-edge role of B cells in mediating antitumor T-cell immunity: Pharmacological strategies for cancer immunotherapy

Emerging evidence reveals the controversial role of B cells in antitumor immunity, but the underlying mechanisms have to be explored. Three latest articles published in the issue 521 of Nature in 2015 reconfirmed the puzzling topic and put forward some explanations of how B cells regulate antitumor T-cell responses both positively and negatively. This paper attempts to demonstrate that different B-cell subpopulations have distinct immunological properties and that they are involved in either antitumor responses or immunosuppression. Recent studies supporting the positive and negative roles of B cells in tumor development were summarized comprehensively. Several specific B-cell subpopulations, such as IgG(+), IgA(+), IL-10(+), and regulatory B cells, were described in detail. The mechanisms underlying the controversial B-cell effects were mainly attributed to different B-cell subpopulations, different B-cell-derived cytokines, direct B cell-T cell interaction, different cancer categories, and different malignant stages, and the immunological interaction between B cells and T cells is mediated by dendritic cells. Promising B-cell-based antitumor strategies were proposed and novel B-cell regulators were summarized to present interesting therapeutic targets. Future investigations are needed to make sure that B-cell-based pharmacological strategies benefit cancer immunotherapy substantially.

Regulatory B cell: New member of immunosuppressive cell club

Historically, the pivotal role of B cells or B lymphocytes in immunity has been attributed to the production of antibodies. They were also demonstrated to present antigens to T cells and to secrete cytokines, thereby acting as positive regulators in immune responses. A series of studies on autoimmune diseases, however, led researchers to find a unique subset of B cells, later described as "regulatory B cells" (Bregs), that has the ability to suppress immune responses. Bregs occur not only in autoimmune diseases, but also in inflammation and transplantation. Furthermore, recently published literatures suggested that Bregs contributed to the growth and metastasis of certain cancers. In this review, we will discuss these unique subsets of B cells in different kinds of disorders, with particular emphasis on the mechanisms of their immunoregulatory role that were collected from mice and humans.

[Rituximab combined with second line regimens for treatment of seven relapsed and refractory Hodgkin lymphoma patients]

目的

探讨利妥昔单抗联合二线方案治疗复发难治性霍奇金淋巴瘤（HL）患者的疗效及安全性。

方法

7例复发难治性HL患者中2例接受R-GDP(E) [利妥昔单抗、吉西他滨、顺铂、地塞米松、（依托泊苷）]方案治疗，2例接受R-IGVP（利妥昔单抗、异环磷酰胺、吉西他滨、长春瑞滨、泼尼松）方案治疗，3例接受R-BEACOPP（利妥昔单抗、博来霉素、依托泊苷、多柔比星、环磷酰胺、长春新碱、甲基苄肼、泼尼松）方案治疗。观察患者治疗过程中及其后的不良反应和疗效。

结果

7例患者中男3例，女4例，发病时中位年龄21(12~36)岁；结节性淋巴细胞为主型HL(NLPHL) 1例，经典型HL 6例（包括4例结节硬化型，1例淋巴细胞为主型和1例混合细胞型)。中位疗程数为4(1~4)个，中位随访时间为29(24~58)个月。7例患者中4例达完全缓解，2例达疾病稳定，1例死亡。2年总生存率为85.7%。不良反应均可耐受，以骨髓抑制为主。5例患者化疗后行外周血自体造血干细胞移植治疗。

结论

利妥昔单抗联合二线方案治疗复发难治性HL患者安全、有效。

Lipid mediator lipoxin A4 inhibits tumor growth by targeting IL-10-producing regulatory B (Breg) cells

Lipoxin A4 (LXA4), an arachidonic acid-derived anti-inflammatory lipid mediator, shows anti-tumor potential by regulating tumor immune microenvironments. However, the underlying molecular and cellular basis of this function remains unclear. IL-10-producing B (Breg) cells display tumor-promoting effects by negatively regulating anti-tumor immunity. Here we show that LXA4 inhibits tumor growth by suppressing the generation of Breg cells in tumor-bearing mice. The administration of LXA4 inhibited the induction of Breg cells. Breg cell deficiency, in turn, resulted in LXA4 losing its anti-tumor properties. Intriguingly, regulatory T (Treg) cells also had a role in this process. Targeting Breg cells by LXA4 decreased the number of Treg cells in draining lymph nodes and tumor tissues as well as enhanced cytotoxic T cell activities. In addition, we further demonstrated that LXA4 inhibited Breg cells through its dephosphorylating STAT3 and ERK. These findings unveil a new anti-tumor mechanism underlying LXA4 targeting Breg cells with potential clinical applications.

Adenoviral-based immunotherapy provides local disease control in an orthotopic murine model of esophageal cancer

Despite recent advances in the development of novel therapies, esophageal carcinoma remains an aggressive cancer associated with a poor prognosis. The lack of a high throughput, reproducible syngeneic animal model that replicates human disease is partly responsible for the paucity of novel therapeutic approaches. In this report, we present the first successful syngeneic, orthotopic model for esophageal cancer. This model was used to test an established adenoviral-based tumor vaccine. We utilized a murine esophageal cancer cell line established from the ED-L2-cyclin D1;p53 mouse that was transduced to express a viral tumor antigen, the Human Papilloma Virus (HPV) E7 protein. The tumor was established in its natural microenvironment at the gastroesophageal junction. Tumor growth was consistent and reproducible. An adenoviral vaccine to E7 (Ad.E7) induced an E7-specific population of functionally active CD8 T cells that trafficked into the tumors and retained cytotoxicity. Ad.E7 vaccination reduced local tumor growth and prolonged overall survival. These findings suggest that orthotopic tumor growth is a reasonable preclinical model to validate novel therapies.

Current approaches in the management of low risk Hodgkin lymphoma in children and adolescents

The outcome for children and adolescents with low risk Hodgkin lymphoma (HL) is excellent, with event-free survival >85% and overall survival >95%. Historically, however, treatment has come at the cost of significant long-term toxicity from chemotherapy, radiation or a combination of these. Recent treatment strategies have focused on maintaining high event-free and overall survival while minimizing the use of therapy associated with late effects. The strategies used to achieve this vary greatly among paediatric cooperative groups and there is no one standard treatment for children with low risk HL. This review summaries recent clinical trials in paediatric low risk HL and addresses some of the important considerations when comparing trials, including differences in the definition of low risk HL, differences in outcome among histological subtypes and varying approaches to reduce or eliminate radiation therapy. Recommendations are provided for the treatment of children with low risk HL outside the setting of a clinical trial.

Splenectomy inhibits non-small cell lung cancer growth by modulating anti-tumor adaptive and innate immune response

It has been shown that inhibitors of the immune system reside in the spleen and inhibit the endogenous antitumor effects of the immune system. We hypothesized that splenectomy would inhibit the growth of relatively large non-small lung cancer (NSCLC) tumors by modulating the systemic inhibition of the immune system, and in particular Myeloid Derived Suppressor Cells (MDSC). The effect of splenectomy was evaluated in several murine lung cancer models. We found that splenectomy reduces tumor growth and the development of lung metastases, but only in advanced tumors. In immune-deficient NOD-SCID mice the effect of splenectomy on tumor growth and metastatic spread disappeared. Splenectomy significantly reduced the presence of MDSC, and especially monocytic-MDSC in the circulation and inside the tumor. Specific reduction of the CCR2+ subset of monocytic MDSC was demonstrated, and the importance of the CCL2-CCR2 axis was further shown by a marked reduction in CCL2 following splenectomy. These changes were followed by changes in the macrophages contents of the tumors to become more antitumorigenic, and by increased activation of CD8⁺ Cytotoxic T-cells (CTL). By MDSC depletion, and adoptive transfer of MDSCs, we demonstrated that the effect of splenectomy on tumor growth was substantially mediated by MDSC cells. We conclude that the spleen is an important contributor to tumor growth and metastases, and that splenectomy can blunt this effect by depletion of MDSC, changing the amount and characteristics of myeloid cells and enhancing activation of CTL.

Engineered fusokine GIFT4 licenses the ability of B cells to trigger a tumoricidal T-cell response

Engineered chimeric cytokines can generate gain-of-function activity in immune cells. Here, we report potent antitumor activity for a novel fusion cytokine generated by N-terminal coupling of GM-CSF to IL4, generating a fusokine termed GIFT4. B cells treated with GIFT4 clustered GM-CSF and IL4 receptors on the cell surface and displayed a pan-STAT hyperphosphorylation associated with acquisition of a distinct phenotype and function described to date. In C57BL/6J mice, administration of GIFT4 expanded endogenous B cells and suppressed the growth of B16F0 melanoma cells. Furthermore, B16F0 melanoma cells engineered to secrete GIFT4 were rejected immunologically in a B-cell-dependent manner. This effect was abolished when GIFT4-expressing B16F0 cells were implanted in B-cell-deficient mice, confirming a B-cell-dependent antitumor effect. Human GIFT4-licensed B cells primed cytotoxic T cells and specifically killed melanoma cells in vitro and in vivo. Taken together, our results demonstrated that GIFT4 could mediate expansion of B cells with potent antigen-specific effector function. GIFT4 may offer a novel immunotherapeutic tool and define a previously unrecognized potential for B cells in melanoma immunotherapy.

Long-lasting complete regression of established mouse tumors by counteracting Th2 inflammation

Mice with intraperitoneal ID8 ovarian carcinoma or subcutaneous SW1 melanoma were injected with monoclonal antibodies (mAbs) to CD137PD-1CTLA4 7-15 days after tumor initiation. Survival of mice with ID8 tumors tripled and >40% of mice with SW1 tumors remained healthy >150 days after last treatment and are probably cured. Therapeutic efficacy was associated with a systemic immune response with memory and antigen specificity, required CD4 cells and involved CD8 cells and NK cells to a less extent. The 3 mAb combination significantly decreased CD19 cells at tumor sites, increased IFN-γ and TNF-α producing CD4 and CD8 T cells and mature CD86 dendritic cells (DC), and it increased the ratios of effector CD4 and CD8 T cells to CD4Foxp3 regulatory T (Treg) cells and to CD11bGr-1 myeloid suppressor cells (MDSC). This is consistent with shifting the tumor microenvironment from an immunosuppressive Th2 to an immunostimulatory Th1 type and is further supported by PCR data. Adding an anti-CD19 mAb to the 3 mAb combination in the SW1 model further increased therapeutic efficacy. Data from ongoing experiments show that intratumoral injection of a combination of mAbs to CD137PD-1CTLA4CD19 can induce complete regression and dramatically prolong survival also in the TC1 carcinoma and B16 melanoma models, suggesting that the approach has general validity.

Margin-infiltrating CD20(+) B cells display an atypical memory phenotype and correlate with favorable prognosis in hepatocellular carcinoma

PURPOSE

The role of infiltrating B cells in hepatocellular carcinoma has been overlooked for many years. This study is aimed to delineate the distribution, prognostic value, and functional status of B cells in human hepatocellular carcinoma.

EXPERIMENTAL DESIGN

Immunohistochemistry was used to investigate the distribution and clinical significance of infiltrating CD20(+) B cells in a series of 120 patients with hepatocellular carcinoma. The results were further tested in an independent series of 200 patients with hepatocellular carcinoma. The functional status of CD20(+) B cells was determined by flow cytometry, immunofluorescence, and in vitro coculture assay.

RESULTS

Infiltrating CD20(+) B cells were predominantly concentrated in the tumor invasive margin, compared with the peri- and intratumor areas. High density of margin-infiltrating B lymphocytes (MIL-B) positively correlated with small tumor size, absence of vascular invasion, and increased density of CD8(+) T cells (P < 0.05). Survival analyses revealed that increased number of MIL-Bs and their penetration through the tumor capsule were significantly associated with improved overall and recurrence-free survival, and were identified as independent prognosticators for patients with hepatocellular carcinoma (P < 0.05). Importantly, the results were further validated in another independent hepatocellular carcinoma cohort. Moreover, we found that MIL-Bs featured an atypical memory phenotype (IgD(-)IgG(+)CD27(-)CD38(-)), expressed surface markers characteristic of antigen-presenting cells, possessed tumor-killing potential by producing IFN-γ, interleukin 12p40 (IL-12p40), granzyme B, and TRAIL, and acted in cooperation with CD8(+) T cells.

CONCLUSIONS

The profile of CD20(+) B cells in situ is a new predictor of prognosis for patients with hepatocellular carcinoma and provides a novel target for an optimal immunotherapy against this fatal malignancy.

Enhanced therapeutic effect of B cell-depleting anti-CD20 antibodies upon combination with in-situ dendritic cell vaccination in advanced lymphoma

The present standard of care for B cell non-Hodgkin's lymphoma includes the anti-CD20 monoclonal antibody rituximab. Although combination treatments with chemotherapy and rituximab improved the duration of remissions and overall survival in indolent B cell lymphoma, the disease is essentially incurable. Thus, new therapeutic approaches are needed. One such approach is active immunization. Given that rituximab depletes both malignant and normal B cells, it is expected to impair humoral immune responses in vaccinated patients. Hence, optimal vaccination strategies for rituximab-treated patients require induction of effector T cells, which can be achieved by dendritic cell (DC) vaccines. We have demonstrated in a mouse model that chemotherapy combined with DC vaccines was therapeutically effective. However, efficacy was related to tumour size at the onset of treatment, decreasing in correlation with increasing tumour burdens. We therefore examined whether, in spite of its low efficacy in advanced disease, DC vaccination may synergize with anti-CD20 antibodies to enhance therapy. Lymphoma-bearing mice were treated with cyclophosphamide, anti-CD20 antibodies and an intratumoral DC vaccine. Results clearly demonstrated the enhanced therapeutic effect of this combination treatment. Thus, under conditions of disseminated disease, when either anti-CD20 antibody treatment or vaccination showed insufficient efficacy, their combination resulted in synergism that mediated long-term survival. We demonstrated further that the combination of antibody and vaccine induced T cell-mediated anti-tumour immune responses with long-term memory. Combination treatments including tumour cell-loaded DC vaccines may therefore provide a strategy for enhancing therapy in rituximab-treated patients.

The immune microenvironment of human tumors: general significance and clinical impact

Human cancers grow in a microenvironment of stromal, inflammatory and immunocompetent cells which is variable from tumor to tumor. The characterization of the immune contexture, i.e. the type, density and functional orientation of immunocompetent cells, the presence or absence of tertiary lymphoid structures is a major prognostic factor for patients survival and represent a guide and a target for innovative cancer therapies.

Immunoglobulin kappa C predicts overall survival in node-negative breast cancer

Background

Biomarkers of the immune system are currently not used as prognostic factors in breast cancer. We analyzed the association of the B cell/plasma cell marker immunoglobulin kappa C (IGKC) and survival of untreated node-negative breast cancer patients.

Material and Methods

IGKC expression was evaluated by immunostaining in a cohort of 335 node-negative breast cancer patients with a median follow-up of 152 months. The prognostic significance of IGKC for disease-free survival (DFS) and breast cancer-specific overall survival (OS) was evaluated with Kaplan-Meier survival analysis as well as univariate and multivariate Cox analysis adjusted for age at diagnosis, pT stage, histological grade, estrogen receptor (ER) status, progesterone receptor (PR) status, Ki-67 and human epidermal growth factor receptor 2 (HER-2) status.

Results

160 patients (47.7%) showed strong expression of IGKC. Univariate analysis showed that IGKC was significantly associated with DFS (P = 0.017, hazard ratio [HR] = 0.570, 95% confidence interval [CI] = 0.360–0.903) and OS (P = 0.011, HR = 0.438, 95% CI = 0.233–0.822) in the entire cohort. The significance of IGKC was especially strong in ER negative and in luminal B carcinomas. In multivariate analysis IGKC retained its significance independent of established clinical factors for DFS (P = 0.004, HR = 0.504, 95% CI = 0.315–0.804) as well as for OS (P = 0.002, HR = 0.371, 95% CI = 0.196–0.705).

Conclusion

Expression of IGKC has an independent protective impact on DFS and OS in node-negative breast cancer.

Inhibition of CD73 improves B cell-mediated anti-tumor immunity in a mouse model of melanoma

CD73 is a cell surface enzyme that suppresses T cell-mediated immune responses by producing extracellular adenosine. Growing evidence suggests that targeting CD73 in cancer may be useful for an effective therapeutic outcome. In this study, we demonstrate that administration of a specific CD73 inhibitor, adenosine 5'-(α,β-methylene)diphosphate (APCP), to melanoma-bearing mice induced a significant tumor regression by promoting the release of Th1- and Th17-associated cytokines in the tumor microenvironment. CD8+ T cells were increased in melanoma tissue of APCP-treated mice. Accordingly, in nude mice APCP failed to reduce tumor growth. Importantly, we observed that after APCP administration, the presence of B cells in the melanoma tissue was greater than that observed in control mice. This was associated with production of IgG2b within the melanoma. Depletion of CD20+ B cells partially blocked the anti-tumor effect of APCP and significantly reduced the production of IgG2b induced by APCP, implying a critical role for B cells in the anti-tumor activity of APCP. Our results also suggest that APCP could influence B cell activity to produce IgG through IL-17A, which significantly increased in the tumor tissue of APCP-treated mice. In support of this, we found that in melanoma-bearing mice receiving anti-IL-17A mAb, the anti-tumor effect of APCP was ablated. This correlated with a reduced capacity of APCP-treated mice to mount an effective immune response against melanoma, as neutralization of this cytokine significantly affected both the CD8+ T cell- and B cell-mediated responses. In conclusion, we demonstrate that both T cells and B cells play a pivotal role in the APCP-induced anti-tumor immune response.

Concordance of preclinical and clinical pharmacology and toxicology of therapeutic monoclonal antibodies and fusion proteins: cell surface targets

Monoclonal antibodies (mAbs) and fusion proteins directed towards cell surface targets make an important contribution to the treatment of disease. The purpose of this review was to correlate the clinical and preclinical data on the 15 currently approved mAbs and fusion proteins targeted to the cell surface. The principal sources used to gather data were: the peer reviewed Literature; European Medicines Agency 'Scientific Discussions'; and the US Food and Drug Administration 'Pharmacology/Toxicology Reviews' and package inserts (United States Prescribing Information). Data on the 15 approved biopharmaceuticals were included: abatacept; abciximab; alefacept; alemtuzumab; basiliximab; cetuximab; daclizumab; efalizumab; ipilimumab; muromonab; natalizumab; panitumumab; rituximab; tocilizumab; and trastuzumab. For statistical analysis of concordance, data from these 15 were combined with data on the approved mAbs and fusion proteins directed towards soluble targets. Good concordance with human pharmacodynamics was found for mice receiving surrogates or non-human primates (NHPs) receiving the human pharmaceutical. In contrast, there was poor concordance for human pharmacodynamics in genetically deficient mice and for human adverse effects in all three test systems. No evidence that NHPs have superior predictive value was found.

B cells are critical to T-cell-mediated antitumor immunity induced by a combined immune-stimulatory/conditionally cytotoxic therapy for glioblastoma

We have demonstrated that modifying the tumor microenvironment through intratumoral administration of adenoviral vectors (Ad) encoding the conditional cytotoxic molecule, i.e., HSV1-TK and the immune-stimulatory cytokine, i.e., fms-like tyrosine kinase 3 ligand (Flt3L) leads to T-cell-dependent tumor regression in rodent models of glioblastoma. We investigated the role of B cells during immune-mediated glioblastoma multiforme regression. Although treatment with Ad-TK+Ad-Flt3L induced tumor regression in 60% of wild-type (WT) mice, it completely failed in B-cell-deficient Igh6(-/-) mice. Tumor-specific T-cell precursors were detected in Ad-TK+Ad-Flt3L-treated WT mice but not in Igh6(-/-) mice. The treatment also failed in WT mice depleted of total B cells or marginal zone B cells. Because we could not detect circulating antibodies against tumor cells and the treatment was equally efficient in WT mice and in mice with B-cell-specific deletion of Prdm 1 (encoding Blimp-1), in which B cells are present but unable to fully differentiate into antibody-secreting plasma cells, tumor regression in this model is not dependent on B cells' production of tumor antigen-specific immunoglobulins. Instead, B cells seem to play a role as antigen-presenting cells (APCs). Treatment with Ad-TK+Ad-Flt3L led to an increase in the number of B cells in the cervical lymph nodes, which stimulated the proliferation of syngeneic T cells and induced clonal expansion of antitumor T cells. Our data show that B cells act as APCs, playing a critical role in clonal expansion of tumor antigen-specific T cells and brain tumor regression.

Phase 2 study of rituximab plus ABVD in patients with newly diagnosed classical Hodgkin lymphoma

In the present study, we evaluated the efficacy and safety of rituximab in combination with standard doxorubicin, bleomycin, vinblastine, and dacarbazine (RABVD) in patients with classical Hodgkin lymphoma (cHL). In this phase 2 study, patients with chemotherapy-naive, advanced-stage cHL were treated with rituximab 375 mg/m(2) weekly for 6 weeks and standard ABVD for 6 cycles. The primary outcome was event-free survival (EFS) at 5 years. Eighty-five patients were enrolled, of whom 78 were eligible. With a median follow-up duration of 68 months (range, 26-110), and based on an intent-to-treat analysis, the 5-year EFS and overall survival rates were 83% and 96%, respectively. The 5-year EFS for patients with stage III/IV cHL was 82%. Furthermore, the 5-year EFS for patients with an International Prognostic Score of 0-2 was 88% and for those with a score of > 2, it was 73%. The most frequent treatment-related grade 3 or 4 adverse events were neutropenia (23%), fatigue (9%), and nausea (8%). Our results demonstrate that the addition of rituximab to ABVD is safe and has a promising clinical activity in patients with advanced-stage cHL. These data are currently being confirmed in a multicenter randomized trial.

The absence of B lymphocytes reduces the number and function of T-regulatory cells and enhances the anti-tumor response in a murine tumor model

Increasing evidence suggests that B lymphocytes play a central role in inhibiting the immune response against certain tumors, but the underlying mechanisms by which B cells facilitate tumor growth are still poorly understood. In this study, we investigated how the presence or absence of B cells affects expansion and function of T-regulatory cells ('T-regs') in a murine breast tumor model (EMT-6). We compared tumor growth, and the number and function of T-reg cells in wild-type immune-competent mice (ICM) and B-cell-deficient mice (BCDM). Mice were either tumor-naive or implanted with EMT-6 mammary adenocarcinoma cells. Tumor growth was markedly inhibited in BCDM, compared to wild-type mice (ICM). Increased T-reg expansion as defined by CD4+/CD25+/FOXP3+ cells was evident following EMT-6 inoculation in ICM in comparison with non-tumor-bearing mice or compared to BCDM in which tumor had been implanted. The percentage and absolute number of T-regs in the spleen, tumor draining lymph nodes, and tumor bed were significantly reduced in BCDM compared to ICM. T-reg function, measured by suppression and proliferation assays, was also reduced in tumor inoculated BCDM compared to ICM. Our studies indicate that absence of B cells may play a role in augmenting the T-cell anti-tumor response, in part due to effects on T-regulatory cell expansion and function.