Multiplex B cell characterization in blood, lymph nodes, and tumors from patients with malignancies

Differentially expressed circular RNA profiles and comprehensive analysis of circRNA-miRNA-mRNA regulatory network in microsatellite instability-high endometrial cancer

The clinical benefit of anti-programmed cell death protein 1 (PD-1)-based immunotherapy among patients with microsatellite instable (MSI) endometrial cancer (EC) precedes that of microsatellite stable (MSS) EC, the mechanisms of which have not been fully understood. Circular RNAs (circRNAs) were reported to modulate immune evasion in several types of malignancies, while their roles in the immune regulation in EC remain largely unknown. Here, we conducted circRNA array analysis and mRNA-Sequencing of 10 MSI EC samples and 10 MSS EC samples and identified 1083 differentially expressed circRNAs (DE-circRNAs) and 864 differentially expressed mRNAs, based on which we constructed a circRNA-miRNA-mRNA comprehensive network consisting of 35 DE-circRNAs, 56 predicted miRNAs and 24 differentially expressed mRNAs. Finally, we confirmed hsa_circ_0058230 being positively correlated with CD8+ T cells infiltration, suggesting that it might take a part in anti-tumor immunity in EC.

Exploring potential roles of long non-coding RNAs in cancer immunotherapy: a comprehensive review

Cancer treatment has long been fraught with challenges, including drug resistance, metastasis, and recurrence, making it one of the most difficult diseases to treat effectively. Traditional therapeutic approaches often fall short due to their inability to target cancer stem cells and the complex genetic and epigenetic landscape of tumors. In recent years, cancer immunotherapy has revolutionized the field, offering new hope and viable alternatives to conventional treatments. A particularly promising area of research focuses on non-coding RNAs (ncRNAs), especially long non-coding RNAs (lncRNAs), and their role in cancer resistance and the modulation of signaling pathways. To address these challenges, we performed a comprehensive review of recent studies on lncRNAs and their impact on cancer immunotherapy. Our review highlights the crucial roles that lncRNAs play in affecting both innate and adaptive immunity, thereby influencing the outcomes of cancer treatments. Key observations from our review indicate that lncRNAs can modify the tumor immune microenvironment, enhance immune cell infiltration, and regulate cytokine production, all of which contribute to tumor growth and resistance to therapies. These insights suggest that lncRNAs could serve as potential targets for precision medicine, opening up new avenues for developing more effective cancer immunotherapies. By compiling recent research on lncRNAs across various cancers, this review aims to shed light on their mechanisms within the tumor immune microenvironment.

Atypical memory B cells increase in the peripheral blood of patients with breast cancer regardless of lymph node involvement

BACKGROUND

Breast cancer is the most common cancer in females. The immune system has a crucial role in the fight against cancer. B and T cells, the two main components of the adaptive immunity, are critical players that specifically target tumor cells. However, B cells, in contrast to T cells, and their role in cancer inhibition or progression is less investigated. Accordingly, in this study, we assessed and compared the frequency of naïve and different subsets of memory B cells in the peripheral blood of patients with breast cancer and healthy women.

RESULTS

We found no significant differences in the frequencies of peripheral CD19+ B cells between the patients and controls. However, there was a significant decrease in the frequency of CD19+IgM+ B cells in patients compared to the control group (P=0.030). Moreover, the patients exhibited higher percentages of atypical memory B cells (CD19+CD27‒IgM‒, P=0.006) and a non-significant increasing trend in switched memory B cells (CD19+CD27+IgM‒, P=0.074). Further analysis revealed a higher frequency of atypical memory B cells (aMBCs) in the peripheral blood of patients without lymph node involvement as well as those with a tumor size greater than 2cm or with estrogen receptor (ER) negative/progesterone receptor (PR) negative tumors, compared with controls (P=0.030, P=0.040, P=0.031 and P=0.054, respectively).

CONCLUSION

Atypical memory B cells (CD19+CD27‒IgM‒) showed a significant increase in the peripheral blood of patients with breast cancer compared to the control group. This increase seems to be associated with tumor characteristics. Nevertheless, additional research is necessary to determine the precise role of these cells during breast cancer progression.

The Evolving Landscape of B Cells in Cancer Metastasis

Metastasis is the leading cause of cancer mortality. Functional and clinical studies have documented diverse B-cell and antibody responses in cancer metastasis. The presence of B cells in tumor microenvironments and metastatic sites has been associated with diverse effects that can promote or inhibit metastasis. Specifically, B cells can contribute to the spread of cancer cells by enhancing tumor cell motility, invasion, angiogenesis, lymphangiogenesis, and extracellular matrix remodeling. Moreover, they can promote metastatic colonization by triggering pathogenic immunoglobulin responses and recruiting immune suppressive cells. Contrastingly, B cells can also exhibit antimetastatic effects. For example, they aid in enhanced antigen presentation, which helps activate immune responses against cancer cells. In addition, B cells play a crucial role in preventing the dissemination of metastatic cells from the primary tumor and secrete antibodies that can aid in tumor recognition. Here, we review the complex roles of B cells in metastasis, delineating the heterogeneity of B-cell activity and subtypes by metastatic site, antibody class, antigen (if known), and molecular phenotype. These important attributes of B cells emphasize the need for a deeper understanding and characterization of B-cell phenotypes to define their effects in metastasis.

CD4, CD20 and PD-L1 as Markers of Recurrence in Non-Muscle-Invasive Bladder Cancer

INTRODUCTION

A tumor microenvironment plays an important role in bladder cancer development and in treatment response.

PURPOSE

The aim of the study was to assess how the components of the microenvironment affect tumor recurrence and to find the potential biomarkers for immunotherapy in NMIBC.

METHODS

The study group consisted of 55 patients with primary NMIBC. Immunohistochemistry was performed on sections of primary papillary urothelial carcinoma of the bladder. Cox proportional hazard multiple regression analysis was performed to characterize tumors with the highest probability of an unfavorable outcome.

RESULTS

Multivariate analysis confirmed that the CD4 (p = 0.001), CD20 (p = 0.008) and PD-L1 expressed on tumor cells (p = 0.01) were independently associated with the risk of recurrence of bladder cancer. Patients with weak CD4+ cell infiltration (<4.6%) and severe CD20+ infiltration (>10%) belong to the group with a lower risk of recurrence. The cancer in this group also frequently recurs after 12 months (p = 0.0005).

CONCLUSIONS

The evaluation of CD4+ and CD20+ cells in the tumor microenvironment, in addition to PD-L1 on tumor cells, facilitates the determination of a group of patients with a low risk of recurrence.

AC1Q3QWB inhibits colorectal cancer progression by modulating the immune response and balancing the structure of the intestinal microbiota

AC1Q3QWB enhances CD8 + T cell response and triggers accumulation of Tregs and B cells.

BACKGROUND

Colorectal cancer (CRC) is a common malignancy with high mortality and few effective therapeutic measures. Gut microbiota dysbiosis and chronic inflammation might contribute to the development of CRC. The present study aimed to explore the effect of AC1Q3QWB (AQB) on colon carcinogenesis in vivo.

METHODS

A mouse colon cancer model was constructed by intraperitoneal injection of 10 mg/kg of Azoxymethane (AOM) and 2 % dextran sodium sulfate (DSS) in drinking water. Mice were randomly assigned to four groups: normal control (NC), AOM/DSS (model control, MC), DMSO + AOM/DSS (DMSO), and AQB + AOM/DSS (AQB). Mice in the AQB group were treated with an intraperitoneal injection of AQB (50 mg/kg) after successful modeling. Then, the disease activity index (DAI) of colitis was analyzed. Colon tissues were collected for hematoxylin-eosin, immunohistochemistry, and microscopic and histological evaluation. Stool samples were collected for microbiota analysis by 16S rRNA sequencing. Blood samples were analyzed by flow cytometry to investigate the inflammatory response.

RESULTS

In AOM/DSS-induced CRC mouse model, AQB treatment dramatically reduced the number and size of colon tumors. AQB treatment enhances CD8+⁺T cell response and triggers the accumulation of CD4+⁺CD25+⁺Foxp3+⁺Regulatory T cells (Tregs) and B cells. AQB regulated the structure and composition of the gut microbiota, which decreased the Firmicutes/Bacteroidetes ratio at the phylum level and increased the abundance of probiotics.

CONCLUSIONS

AQB has potent antitumor activity against colorectal cancer in vivo by a mechanism that might involve modulation of the immune system and alteration of the intestinal microbiota.

Immune-Activated B Cells Are Dominant in Prostate Cancer

B cells are multifaceted immune cells responding robustly during immune surveillance against tumor antigens by presentation to T cells and switched immunoglobulin production. However, B cells are unstudied in prostate cancer (PCa). We used flow cytometry to analyze B-cell subpopulations in peripheral blood and lymph nodes from intermediate-high risk PCa patients. B-cell subpopulations were related to clinicopathological factors. B-cell-receptor single-cell sequencing and VDJ analysis identified clonal B-cell expansion in blood and lymph nodes. Pathological staging was pT2 in 16%, pT3a in 48%, and pT3b in 36%. Lymph node metastases occurred in 5/25 patients (20%). Compared to healthy donors, the peripheral blood CD19⁺ B-cell compartment was significantly decreased in PCa patients and dominated by naïve B cells. The nodal B-cell compartment had significantly increased fractions of CD19⁺ B cells and switched memory B cells. Plasmablasts were observed in tumor-draining sentinel lymph nodes (SNs). VDJ analysis revealed clonal expansion in lymph nodes. Thus, activated B cells are increased in SNs from PCa patients. The increased fraction of switched memory cells and plasmablasts together with the presence of clonally expanded B cells indicate tumor-specific T-cell-dependent responses from B cells, supporting an important role for B cells in the protection against tumors.

Activation of B cells in Tertiary Lymphoid Structures in cancer: Anti-tumor or anti-self?

Whereas T cells in the tumor microenvironment have been the main focus as cancer controlling cells and targets of immunotherapies, B cells have recently gained strong attention. Being associated to Tertiary Lymphoid Structures (TLS) located at the vicinity of tumor nests, the fate of B cell depends on TLS maturity. In immature TLS they may evolve as regulatory B cells producing immunosuppressive cytokines and promote tumor growth. In mature TLS with a germinal center, B cells are selected, amplified, undergo affinity maturation and isotypic switching, resulting in plasma cell generation and production of anti-tumor antibodies. In that case, they are associated with longer patient's survival and therapeutic response to immunotherapy. Identification of tumor specific, or tumor overexpressed, antigens recognized by "in situ" produced antibodies and their discrimination from self-antigens induced by ICI treatments is a major challenge to develop novel antibody-based immunotherapies.

Impact of interaction networks of B cells with other cells on tumorigenesis, progression and response to immunotherapy of renal cell carcinoma: A review

Ample evidence indicates that the development and progression of renal cell carcinoma (RCC) are complex pathological processes involving interactions between tumor cells, immune cells and stromal components. Tumor infiltrated immune cells determine whether tumor advancement is promoted or inhibited. Among them, infiltrated B lymphocytes are present in all stages of RCC, playing a major role in determining tumor formation and advancement, as an essential part in the tumor microenvironment (TME). Although the advent of targeted and immune therapies has remarkably improved the survival of patients with advanced RCC, few cases can achieve complete response due to drug resistance. In this review article, we intend to summary the recent studies that outline the interaction networks of B cells with other cells, discuss the role of B cells in RCC development and progression, and assess their impact on RCC immunotherapy.

Reprogramming of sentinel lymph node microenvironment during tumor metastasis

Metastasis is a major cause of death in patients with cancer. The two main routes for cancer cell dissemination are the blood and lymphatic systems. The underlying mechanism of hematogenous metastasis has been well characterized in the past few decades. However, our understanding of the molecular basis of lymphatic metastasis remains at a premature stage. Conceptually, cancer cells invade into lymphatic capillary, passively move to collecting lymphatic vessels, migrate into sentinel lymph node (SLN;, the first lymph node to which cancer cells spread from the primary tumor), and enter the blood circulatory system via the subclavian vein. Before arriving, cancer cells release specific soluble factors to modulate the microenvironment in SLN to establish a beachhead for successful colonization. After colonization, cancer cells inhibit anti-tumor immunity by inducing the recruitment of regulatory T cell and myeloid-derived suppressor cells, suppressing the function of dendritic cell and CD8⁺ T cell, and promoting the release of immunosuppressive cytokines. The development of novel strategies to reverse cancer cell-triggered SLN remodeling may re-activate immunity to reduce beachhead buildup and distant metastasis. In addition to being a microanatomic location for metastasis, the SLN is also an important site for immune modulation. Nanotechnology-based approaches to deliver lymph node-tropic antibodies or drug-conjugated nanoparticles to kill cancer cells on site are a new direction for cancer treatment. Conversely, the induction of stronger immunity by promoting antigen presentation in lymph nodes provides an alternate way to enhance the efficacy of immune checkpoint therapy and cancer vaccine. In this review article, we summarize recent findings on the reprogramming of SLN during lymphatic invasion and discuss the possibility of inhibiting tumor metastasis and eliciting anti-tumor immunity by targeting SLN.

Deconstructing Immune Cell Infiltration in Human Colorectal Cancer: A Systematic Spatiotemporal Evaluation

Cancer-related immunity has been identified as playing a key role in the outcome of colorectal cancer (CRC); however, the exact mechanisms are only partially understood. In this study, we evaluated a total of 242 surgical specimen of CRC patients using tissue microarrays and immunohistochemistry to evaluate tumor infiltrating immune cells (CD3, CD4, CD8, CD20, CD23, CD45 and CD56) and immune checkpoint markers (CTLA-4, PD-L1, PD-1) in systematically selected tumor regions and their corresponding lymph nodes, as well as in liver metastases. Additionally, an immune panel gene expression assay was performed on 12 primary tumors and 12 consecutive liver metastases. A higher number of natural killer cells and more mature B cells along with PD-1⁺ expressing cells were observed in the main tumor area as compared to metastases. A higher number of metastatic lymph nodes were associated with significantly lower B cell counts. With more advanced lymph node metastatic status, higher leukocyte—particularly T cell numbers—were observed. Eleven differentially expressed immune-related genes were found between primary tumors and liver metastases. Also, alterations of the innate immune response and the tumor necrosis factor superfamily pathways had been identified.

B cells in pancreatic cancer stroma

Pancreatic cancer is a disease with high unmet clinical need. Pancreatic cancer is also characterised by an intense fibrotic stroma, which harbours many immune cells. Studies in both human and animal models have demonstrated that the immune system plays a crucial role in modulating tumour onset and progression. In human pancreatic ductal adenocarcinoma, high B-cell infiltration correlates with better patient survival. Hence, B cells have received recent interest in pancreatic cancer as potential therapeutic targets. However, the data on the role of B cells in murine models is unclear as it is dependent on the pancreatic cancer model used to study. Nevertheless, it appears that B cells do organise along with other immune cells such as a network of follicular dendritic cells (DCs), surrounded by T cells and DCs to form tertiary lymphoid structures (TLS). TLS are increasingly recognised as sites for antigen presentation, T-cell activation, B-cell maturation and differentiation in plasma cells. In this review we dissect the role of B cells and provide directions for future studies to harness the role of B cells in treatment of human pancreatic cancer.

The Role of the Tumor Microenvironment and Treatment Strategies in Colorectal Cancer

Colorectal cancer (CRC) has the second highest mortality rate among all cancers worldwide. Surgery, chemotherapy, radiotherapy, molecular targeting and other treatment methods have significantly prolonged the survival of patients with CRC. Recently, the emergence of tumor immunotherapy represented by immune checkpoint inhibitors (ICIs) has brought new immunotherapy options for the treatment of advanced CRC. As the efficacy of ICIs is closely related to the tumor immune microenvironment (TME), it is necessary to clarify the relationship between the immune microenvironment of CRC and the efficacy of immunotherapy to ensure that the appropriate drugs are selected. We herein review the latest research progress in the immune microenvironment and strategies related to immunotherapy for CRC. We hope that this review helps in the selection of appropriate treatment strategies for CRC patients.

Long noncoding RNA: a dazzling dancer in tumor immune microenvironment

Long noncoding RNAs (lncRNAs) are a class of endogenous, non-protein coding RNAs that are highly linked to various cellular functions and pathological process. Emerging evidence indicates that lncRNAs participate in crosstalk between tumor and stroma, and reprogramming of tumor immune microenvironment (TIME). TIME possesses distinct populations of myeloid cells and lymphocytes to influence the immune escape of cancer, the response to immunotherapy, and the survival of patients. However, hitherto, a comprehensive review aiming at relationship between lncRNAs and TIME is missing. In this review, we focus on the functional roles and molecular mechanisms of lncRNAs within the TIME. Furthermore, we discussed the potential immunotherapeutic strategies based on lncRNAs and their limitations.

Cancer treatment in the lymphatic system: A prospective targeting employing nanostructured systems

Cancer related to lymphangiogenesis has gained a great deal of attention in recent decades ever since specific markers of this intriguing system were discovered. Unlike the blood system, the lymphatic system has unique features that can advance cancer in future metastasis, or, conversely, can provide an opportunity to prevent or treat this disease that affects people worldwide. The aim of this review is to show the recent research of cancer treatment associated with the lymphatic system, considered one of the main gateways for disseminating metastatic cells to distant organs. Nanostructured systems based on theranostics and immunotherapies can offer several options for this complex disease. Precision targeting and accumulation of nanomaterials into the tumor sites and their elimination, or targeting the specific immune defense cells to promote optimal regression of cancer cells are highlighted in this paper. Moreover, therapies based on nanostructured systems through lymphatic systems may reduce the side effects and toxicity, avoid first pass hepatic metabolism, and improve patient recovery. We emphasize the general understanding of the association between the immune and lymphatic systems, their interaction with tumor cells, the mechanisms involved and the recent developments in several nanotechnology treatments related to this disease.

Tumour-reactive B cells and antibody responses after allogeneic haematopoietic cell transplantation

For many high-risk haematologic malignancies, such as acute myeloid leukaemia, the success of therapy relies mainly on invoking a curative antitumour immune response. This can be achieved by inducing a graft-versus-leukaemia response following allogeneic haematopoietic cell transplantation. While the contribution of T cells and natural killer cells to graft-versus-leukaemia responses is established, the contribution of B cells and antibodies is relatively unexplored. This article reviews what is known about the contribution of B cells and tumour-specific antibody responses to a successful graft-versus-leukaemia response leading to eradication of the tumour.

Decreased of BAFF-R expression and B cells maturation in patients with hepatitis B virus-related hepatocellular carcinoma

BACKGROUND

Recent evidence has indicated the role of B cells and B cell-activating factor (BAFF) in the development of hepatocellular carcinoma (HCC).

AIM

To characterize circulating BAFF receptor expression and B cell subpopulations in patients with hepatitis B virus (HBV)-related HCC.

METHODS

Peripheral blood samples collected from 41 patients with chronic HBV infection (25 patients without HCC and 16 patients with HCC) and 9 healthy controls were assessed for BAFF receptors [BAFF-R(B cell-activating factor receptor), transmembrane activator and cyclophilin ligand interactor, B-cell maturation antigen] and B cell subpopulations by multicolor flow cytometry.

RESULTS

The frequency of BAFF-R expressing B cells to total B cells was significantly lower in patients with HCC (3.39% ± 2.12%) compared with the non-HCC group (5.37% ± 1.90%) and healthy controls (6.23% ± 2.32%), whereas there was no difference in transmembrane activator and cyclophilin ligand interactor and B-cell maturation antigen. The frequencies of CD27⁺IgD⁺ memory B cells, CD27⁺IgD^- class-switched memory B cells and plasmablasts were significantly lower in the patients with HCC compared to patients without HCC (1.23 ± 1.17 vs 3.09 ± 1.55, P = 0.001, 0.60 ± 0.44 vs 1.69 ± 0.86, P < 0.0001 and 0.16 ± 0.12 vs 0.37 ± 0.30, P = 0.014, respectively). However, the ratio of naïve and transitional B cell did not differ significantly between the three groups. In addition, decreased BAFF-R expression on B cells was significantly correlated with large tumor size and advanced tumor stage.

CONCLUSION

Our data demonstrated BAFF-R expression was reduced in B cells that involved with the frequencies of B cells maturation in patients with HCC. The depletion of BAFF-R might play an important role in the development of HCC in patients with chronic HBV infection.

Colorectal Cancer Immune Infiltrates: Significance in Patient Prognosis and Immunotherapeutic Efficacy

Colorectal cancer occurrence and progression involve multiple aspects of host immune deficiencies. In these events, immune cells vary their phenotypes and functions over time, thus enabling the immune microenvironment to be “tumor-inhibiting” as well as “tumor-promoting” as a whole. Because of the association of tumoricidal T cell infiltration with favorable survival in cancer patients, the Immunoscore system was established. Critically, the tumoral Immunoscore serves as an indicator of CRC patient prognosis independent of patient TNM stage and suggests that patients with high Immunoscores in their tumors have prolonged survival in general. Accordingly, stratifications according to tumoral Immunoscores provide new insights into CRC in terms of comparing disease severity, forecasting disease progression, and making treatment decisions. An important application of this system will be to shed light on candidate selection in immunotherapy for CRC, because the T cells responsible for determining the Immunoscore serve as responders to immune checkpoint inhibitors. However, the Immunoscore system merely provides a standard procedure for identifying the tumoral infiltration of cytotoxic and memory T cells, while information concerning the survival and function of these cells is still absent. Moreover, other infiltrates, such as dendritic cells, macrophages, and B cells, can still influence CRC prognosis, implying that those might also influence the therapeutic efficacy of immune checkpoint inhibitors. On these bases, this review is designed to introduce the Immunoscore system by presenting its clinical significance and application in CRC.

Cytokine profiling of tumor-infiltrating T lymphocytes by flow cytometry

Intracellular cytokine staining (ICS) utilizing fluorescently labeled, cytokine-specific antibodies is a powerful technique utilized to evaluate cytokine expression that provides resolution at the single cell level. Combined with multi-parameter flow cytometry, ICS can provide detailed information on complex cytokine profiles and cellular phenotypes within the tumor microenvironment, particularly for the CD4⁺ T helper and CD8⁺ cytotoxic T cell compartments. This technique provides critical information concerning tumor-infiltrating T cell function that is essential for evaluating existing or therapeutically-induced tumor antigen-specific T cell responses in both preclinical models and cancer patients. In this chapter we will discuss in detail the critical steps necessary for a successful ICS assay and outline common protocols for the evaluation of cytokine production from T cell subsets present within the tumor microenvironment.

Tumour-associated B cells in urothelial urinary bladder cancer

Tumour infiltrating B cells and CD38⁺ plasma cells have been correlated with survival in different malignancies but their role in urinary bladder cancer is unclear. IL-10 is a multifunctional cytokine with both anti-inflammatory and immunostimulatory properties, that can be released by regulatory B cells (Bregs). We have stained paraffin-embedded tumour sections from 31 patients with invasive urothelial urinary bladder cancer with respect to CD20⁺ B cells, CD38⁺ cells, IL-10-expressing cells, IgG, C1q and C3a and analysed the impact of these markers on survival. Interestingly, we observe tumour-associated CD20⁺ B cells forming follicle-like structures in tumours of some patients. We demonstrate that follicle-like structures, tumour-associated CD38⁺ cells, IL-10 produced by non-B cells, tumour infiltrating IgG and activation of the complement system, may associate to longer survival of urinary bladder cancer patients. IL-10 expression by tumour-associated Bregs may instead negatively affect prognosis. More research is needed to fully understand the role of B cells and IL-10 in urinary bladder cancer.

Evaluation of the frequency of CD5+ B cells as natural immunoglobulin M producers and circulating soluble CD5 in patients with bladder cancer

Bladder cancer is the most common malignancy of the genitourinary tract. It is the fourth most common malignancy in men and the fifth most common malignancy in the general population, with a high recurrence rate. CD5⁺ B lymphocytes are a subset of B lymphocytes, which contribute to innate immune responses. These cells are involved in the spontaneous production of self-reactive natural antibodies. On the other hand, natural antibodies can recognize tumor-associated antigens, including proteins or carbohydrates, and eliminate these cells in a complement-dependent manner or via induction of apoptosis. Besides surface CD5, the soluble form of this molecule is involved in the regulation of immune system. Considering the role of CD5⁺ B cells in the production of natural immunoglobulin M (IgM) and role of these antibodies in antitumor responses, in this study, we aimed to investigate the frequency of CD5 in B cells and to evaluate the diagnostic potential of these cells and also soluble CD5 (sCD5) in patients with bladder cancer. Blood specimens were collected from 40 patients with bladder cancer, who were referred to Sina Hospital in Tehran, IRAN. The levels of CD5⁺ and CD5^- B lymphocytes were measured in the peripheral blood via flow cytometry, and the levels of sCD5 and total IgM were investigated in the serum by ELISA and nephlometry techniques, respectively. The frequency of CD5⁺ and CD5^- B cells was significantly lower in patients, compared with the healthy controls. Detectable levels of sCD5 were found in two patients (5%), while total IgM showed no significant difference between the patient and control groups. The present results suggest that B cell subsets may be affected by malignancy. Therefore, further research is needed to identify B cells and their soluble markers for diagnosis of patients with bladder cancer.

Immunological features of a lung cancer patient achieving an objective response with anti-programmed death-1 blockade therapy

The role of immune checkpoint inhibitors in metastatic lung cancer has been established in recent years and the pretherapeutic profiles of the tumor microenvironment in responders have been increasingly reported. The role of salvage surgery and the immune profiles of the posttherapeutic specimens in patients achieving an objective response have rarely been studied. We report a case of metastatic lung cancer treated by anti‐programmed death‐1 Ab followed by surgical resection. The immune status of the tumor was assessed, showing germinal center formation, memory B cell infiltration, and a high frequency of interferon gamma ‐secreting T cells.

Evaluation of the frequency of CD5+ B cells as natural immunoglobulin M producers and circulating soluble CD5 in patients with bladder cancer

Bladder cancer is the most common malignancy of the genitourinary tract. It is the fourth most common malignancy in men and the fifth most common malignancy in the general population, with a high recurrence rate. CD5⁺ B lymphocytes are a subset of B lymphocytes, which contribute to innate immune responses. These cells are involved in the spontaneous production of self-reactive natural antibodies. On the other hand, natural antibodies can recognize tumor-associated antigens, including proteins or carbohydrates, and eliminate these cells in a complement-dependent manner or via induction of apoptosis. Besides surface CD5, the soluble form of this molecule is involved in the regulation of immune system. Considering the role of CD5⁺ B cells in the production of natural immunoglobulin M (IgM) and role of these antibodies in antitumor responses, in this study, we aimed to investigate the frequency of CD5 in B cells and to evaluate the diagnostic potential of these cells and also soluble CD5 (sCD5) in patients with bladder cancer. Blood specimens were collected from 40 patients with bladder cancer, who were referred to Sina Hospital in Tehran, IRAN. The levels of CD5⁺ and CD5^- B lymphocytes were measured in the peripheral blood via flow cytometry, and the levels of sCD5 and total IgM were investigated in the serum by ELISA and nephlometry techniques, respectively. The frequency of CD5⁺ and CD5^- B cells was significantly lower in patients, compared with the healthy controls. Detectable levels of sCD5 were found in two patients (5%), while total IgM showed no significant difference between the patient and control groups. The present results suggest that B cell subsets may be affected by malignancy. Therefore, further research is needed to identify B cells and their soluble markers for diagnosis of patients with bladder cancer.

Examining Peripheral and Tumor Cellular Immunome in Patients With Cancer

Immunotherapies are rapidly being integrated into standard of care (SOC) therapy in conjunction with surgery, chemotherapy, and radiotherapy for many cancers and a large number of clinical studies continue to explore immunotherapy alone and as part of combination therapies in patients with cancer. It is evident that clinical effectiveness of immunotherapy is limited to a subset of patients and improving immunotherapy related outcomes remains a major scientific and clinical effort. Understanding the immune cell subset phenotype and activation/functional status (cellular immunome) prior to and post therapy is therefore critical to develop biomarkers that (1) will predict if a patient will respond to immunotherapy and (2) are a result of immunotherapy. In this study, we investigated local (tumor) and peripheral (blood) cellular immunome of patients with melanoma, breast cancer, and brain cancer using a rapid and reliable standardized, multiparameter flow cytometry assay. We used this approach to monitor changes in the peripheral cellular immunome in women with breast cancer undergoing SOC therapy. Our analysis is unique because it is conducted using matched fresh tumor tissue and blood from patients in real-time, within 2–3 h of sample acquisition, and provides insight into the innate and adaptive immune cell profile in blood and tumor. Specific to blood, this approach involves no manipulation and evaluates all immune subsets such as T cells, B cells, natural killer (NK) cells, monocytes, dendritic cells (DCs), neutrophils, eosinophils, and basophils using 0.5 ml of blood. Analysis of the corresponding tumor provides much needed insight into the phenotype and activation status of immune cells, especially T and B cells, in the tumor microenvironment vs. the periphery. This analysis will be used to assess baseline and therapy-mediated changes in local and peripheral cellular immunome in patients with glioblastoma, breast cancer, and melanoma in planned immunotherapy clinical studies.

B cells in esophago-gastric adenocarcinoma are highly differentiated, organize in tertiary lymphoid structures and produce tumor-specific antibodies

Tumor-infiltrating lymphocytes (TILs) are correlated to prognosis of several kinds of cancer. Most studies focused on T cells, while the role of tumor-associated B cells (TABs) has only recently gained more attention. TABs contain subpopulations with distinct functions, potentially promoting or inhibiting immune responses. This study provides a detailed analysis of TABs in gastro-esophageal adenocarcinoma (EAC). Flow cytometric analyses of single cell suspensions of tumor samples, mucosa, lymph nodes and peripheral blood mononuclear cells (PBMC) of EAC patients and healthy controls revealed a distinct B cell compartment in cancer patients. B cells were increased in tumor samples and subset-analyses of TILs showed increased proportions of differentiated and activated B cells and an enrichment for follicular T helper cells. Confocal microscopy demonstrated that TABs were mainly organized in tertiary lymphoid structures (TLS), which resemble lymphoid follicles in secondary lymphoid organs. A panel of 34 tumor-associated antigens (TAAs) expressed in EAC was identified based on public databases and TCGA data to analyze tumor-specific B cell responses using a LUMINEXTM bead assay and flow cytometry. Structural analyses of TLS and the detection of tumor-specific antibodies against one or more TAAs in 48.1% of analyzed serum samples underline presence of anti-tumor B cell responses in EAC. Interestingly, B cells were decreased in tumors with expression of Programmed Death Ligand 1 or impaired HLA-I expression. These data demonstrate that anti-tumor B cell responses are an additional and underestimated aspect of EAC. Our results are of immediate translational relevance to emerging immunotherapies.

Activated naïve B cells promote development of malignant pleural effusion by differential regulation of TH1 and TH17 response

Inflammatory signaling networks between tumor cells and immune cells contribute to the development of malignant pleural effusion (MPE). B cells have been found in MPE; however, little is known about their roles there. In the present study, by using mouse MPE models, we noted that although the total B cells in MPE were decreased as compared with the corresponding blood and spleen, the percentage of activated naïve B cells expressing higher levels of CD80, CD86, myosin heavy chain-II, CD44, CD69, and programmed cell death-ligand 1 (PD-L1) molecules were increased in wild-type mouse MPE. Compared with wild-type mice, decreased T helper (T_H)1 cells and increased T_H17 cells were present in B cell-deficient mouse MPE, which paralleled to the reduced MPE volume and longer survival time. Adoptive transfer of activated naïve B cells into B cell-deficient mice was able to increase T_H1 cells and decrease T_H17 cells in MPE and shorten the survival of mice bearing MPE. Furthermore, we demonstrated that activated naïve B cells inhibited T_H17-cell expansion via the PD-1/PD-L1 pathway and promoted naïve CD4⁺ T-cell differentiation into T_H1/T_H17 cells through secreting IL-27/IL-6 independent of the PD-1/PD-L1 pathway. Collectively, our data uncovered a mechanism by which naïve B cells promote MPE formation by regulating T_H1/T_H17 cell responses, making these B cells an attractive target for therapeutic intervention in the fight against cancer.

MicroRNAs 15A and 16-1 Activate Signaling Pathways That Mediate Chemotaxis of Immune Regulatory B cells to Colorectal Tumors

BACKGROUND & AIMS

B cells infiltrate tumors, but little is known about how they affect tumor growth and progression. microRNA15A (MIR15A or miRNA15A) and microRNA16-1 (MIR16-1 or miRNA16-1) regulate cell proliferation, apoptosis, and drug resistance. We investigated their involvement in B-cell-mediated immune suppression by colorectal tumors.

METHODS

Mice with disruptions of the gene cluster that encodes MIR15A and MIR16-1 (knockout mice), and control (C57BL/B6) mice were given azoxymethane with dextran sodium sulfate (AD) to induce formation of colorectal tumors. Mice were given anti-CD20 to delete B cells, or injections of agomir to increase MIR15A and MIR16-1. Proliferation of CD8⁺T cells was measured by carboxyfluorescein-succinimidyl-ester analysis. Colon tissues were collected from mice and analyzed by flow cytometry, microRNA (miRNA) sequencing, and for cytokine production. Intestinal epithelial cells (IECs) were isolated and transfected with miRNA mimics, to identify their targets. We analyzed miRNA expression patterns and quantified B cells in colorectal cancer tissue microarrays derived from 90 patients who underwent surgical resection, from July 2006 through April 2008, in Shanghai, China; expression data were compared with clinical outcomes.

RESULTS

Tumors that developed in knockout mice following administration of AD were larger and contained greater numbers of B cells than tumors that grew in control mice. Most of the B cells in the tumors were positive for immunoglobulin A (IgA⁺). IgA⁺ B cells expressed high levels of immune regulatory molecules (programmed death ligand 1, interleukin 10, and transforming growth factor beta), and repressed the proliferation and activation of CD8⁺ T cells. Levels of MIR15A and MIR16-1 were reduced in colon tumors from mice, compared with nontumor colon tissue. Incubation of IECs with IL17A reduced expression of MIR15A and MIR16-1. Transgenic expression of MIR15A and MIR16-1 in IECs decreased activation of NF-κB and STAT1 by reducing expression of I-kappaB kinases; this resulted in reduced production of chemokine (C-X-C motif) ligands 9 and 10 and decreased chemotaxis of IgA⁺ B cells. Tumors in mice injected with AD and agomir grew more slowly than tumors in mice not given in agomir and contained fewer IgA⁺ B cells. We found a negative correlation between levels of MIR15A and MIR16-1 and numbers of IgA⁺B cells in human colorectal tumor tissues; high levels of MIR15A and MIR16-1 and low numbers of IgA⁺B cells were associated with longer survival times of patients.

CONCLUSIONS

We found increased levels of MIR15A and MIR16-1 to reduce numbers of IgA⁺ B cells in colorectal tumor tissues and correlate with increased survival time of patients. In mice that lack MIR15A and MIR16-1, colon tumors grow more rapidly and contain increased numbers of IgA⁺ B cells. MIR15A and MIR16-1 appear to activate signaling pathways required for B-cell-mediated immune suppression.

A specific immune and lymphatic profile characterizes the pre-metastatic state of the sentinel lymph node in patients with early cervical cancer

The lymph node (LN) pre-metastatic niche is faintly characterized in lymphophilic human neoplasia, although LN metastasis is considered as the strongest prognostic marker of patient survival. Due to its specific dissemination through a complex bilateral pelvic lymphatic system, early cervical cancer is a relevant candidate for investigating the early nodal metastatic process. In the present study, we analyzed in-depth both the lymphatic vasculature and the immune climate of pre-metastatic sentinel LN (SLN), in 48 cases of FIGO stage IB1 cervical neoplasms. An original digital image analysis methodology was used to objectively determine whole slide densities and spatial distributions of immunostained structures. We observed a marked increase in lymphatic vessel density (LVD) and a specific capsular and subcapsular distribution in pre-metastatic SLN when compared with non-sentinel counterparts. Such features persisted in the presence of nodal metastatic colonization. The inflammatory profile attested by CD8⁺, Foxp3, CD20 and PD-1expression was also significantly increased in pre-metastatic SLN. Remarkably, the densities of CD20⁺ B cells and PD-1 expressing germinal centers were positively correlated with LVD. All together, these data strongly support the existence of a pre-metastatic dialog between the primary tumor and the first nodal relay. Both lymphatic and immune responses contribute to the elaboration of a specific pre-metastatic microenvironment in human SLN. Moreover, this work provides evidence that, in the context of early cervical cancer, a pre-metastatic lymphangiogenesis occurs within the SLN (pre-metastatic niche) and is associated with a specific humoral immune response.

Herpesviruses dUTPases: A New Family of Pathogen-Associated Molecular Pattern (PAMP) Proteins with Implications for Human Disease

The human herpesviruses are ubiquitous viruses and have a prevalence of over 90% in the adult population. Following a primary infection they establish latency and can be reactivated over a person's lifetime. While it is well accepted that human herpesviruses are implicated in numerous diseases ranging from dermatological and autoimmune disease to cancer, the role of lytic proteins in the pathophysiology of herpesvirus-associated diseases remains largely understudies. Only recently have we begun to appreciate the importance of lytic proteins produced during reactivation of the virus, in particular the deoxyuridine triphosphate nucleotidohydrolases (dUTPase), as key modulators of the host innate and adaptive immune responses. In this review, we provide evidence from animal and human studies of the Epstein-Barr virus as a prototype, supporting the notion that herpesviruses dUTPases are a family of proteins with unique immunoregulatory functions that can alter the inflammatory microenvironment and thus exacerbate the immune pathology of herpesvirus-related diseases including myalgic encephalomyelitis/chronic fatigue syndrome, autoimmune diseases, and cancer.

Doxorubicin enhances the capacity of B cells to activate T cells in urothelial urinary bladder cancer

Cancer is currently treated by a combination of therapies, including chemotherapy which is believed to suppress the immune system. Combination of immunotherapy and chemotherapy correlates with improved survival but needs careful planning in order to achieve a synergistic effect. In this study, we have demonstrated that doxorubicin treatment of B cells resulted in increased expression of CD86 and concordantly increased CD4⁺ T cell activation in the presence of superantigen, an effect that was inhibited by the addition of a CD86 blocking antibody. Furthermore, doxorubicin resulted in decreased expression of the anti-inflammatory cytokines IL-10 and TNF-α. Finally, B cells from urinary bladder cancer patients, treated with a neoadjuvant regiment containing doxorubicin, displayed increased CD86-expression. We conclude that doxorubicin induces CD86 expression on B cells and hence enhances their antigen-presenting ability in vitro, a finding verified in patients. Development of tailored time and dose schedules may increase the effectiveness of combining chemotherapy and immunotherapy.

Immune cell recruitment in teratomas is impaired by increased Wnt secretion

Wnt signaling plays a central role in tumor initiation and tumor progression. Mutations in Wnt pathway components, such as the tumor suppressor APC, lead to malignant transformation. While previous studies focused on Wnt-related changes in cancer cells, the impact of aberrant Wnt signaling on the tumor microenvironment is only beginning to emerge. In order to investigate the role of increased Wnt secretion on tumor growth and the microenvironment, we generated a novel germ cell tumor model by overexpressing the Wnt secretion factor Evi/Wls in mouse embryonic stem cells. Evi-overexpressing teratoma were characterized by enhanced tumor growth in supporting a tumor-promoting role of Wnt secretion. Interestingly, enhanced Evi expression correlated with impaired immune cell recruitment. Specifically, T- and B-cell infiltration was reduced in Evi-overexpressing teratomas, which was independent of teratoma size and differentiation. Our study suggests that Wnt secretion impairs immunosurveillance. Since immune cell infiltration has been shown to have prognostic value, the levels of secreted Wnt activity might impact the efficiency of cancer immunotherapy.

Tumor-secreted products repress B-cell lymphopoiesis in a murine model of breast cancer

Growing cancers are known to modify immune responses through suppressive mechanisms manifested within the local tumor microenvironment. Accumulating evidence indicates that secreted tumor products can also influence on distant immunological compartments, including myelopoiesis in the bone marrow. However, it is unknown if a similar effect can occur to regulate B-cell lymphopoiesis in breast cancer. Examining the MMTV-PyMT murine model of breast cancer, we show a complete block in bone marrow B-cell lymphopoiesis, which is dependent on tumor burden. We also observed an increase in the total number of splenic B cells and an elevated frequency of marginal zone B cells. By using in vitro assays of B-cell lymphopoiesis, we show that tumor-secreted molecules directly inhibit B-cell progenitor proliferation and favor maturation. These data demonstrate a profound sensitivity of B-cell lymphopoiesis to the accumulation of ectopically produced molecules during tumor growth in PyMT.

Tumor microenvironment B cells increase bladder cancer metastasis via modulation of the IL-8/androgen receptor (AR)/MMPs signals

While B cells in the tumor microenvironment may play important roles in cancer progression, their impacts on the bladder cancer (BCa) metastasis remain unclear. Here we found from human clinical BCa samples that BCa tissues could recruit more B cells than the surrounding normal bladder tissues and the in vitro co-culture assay also demonstrated that B cells could be recruited more easily towards BCa cells compared to normal bladder cells. Chamber invasion and 3D invasion assays showed the recruited B cells could then significantly increase the BCa cell invasion. Mechanism dissection found that recruited B cells could increase IL-8/androgen receptor (AR) signals in BCa cells that could then promote the expression of metastasis genes including MMP1 and MMP13. Blocking the IL-8/AR/MMPs signals either by anti-IL-8 neutralizing antibody, AR-siRNA, or MMPs inhibitors all partially reversed the infiltrating B cells capacity to increase the BCa cell invasion. The in vivo data from orthotopically xenografted BCa mouse model also confirmed that infiltrating B cells could increase BCa cell invasion via increasing AR signals. Together, these results demonstrate the key roles of B cells within the bladder tumor microenvironment that increase the BCa metastasis and may help us to develop the potential therapies via targeting these newly identified IL-8/AR/MMPs signals to better battle the BCa progression.

An adaptive immune response driven by mature, antigen-experienced T and B cells within the microenvironment of oral squamous cell carcinoma

Lymphocyte infiltrates have been observed in the microenvironment of oral cancer; however, little is known about whether the immune response of the lymphocyte infiltrate affects tumor biology. For a deeper understanding of the role of the infiltrating-lymphocytes in oral squamous cell carcinoma (OSCC), we characterized the lymphocyte infiltrate repertoires and defined their features. Immunohistochemistry revealed considerable T and B cell infiltrates and lymphoid follicles with germinal center-like structures within the tumor microenvironment. Flow cytometry demonstrated that populations of antigen-experienced CD4+ and CD8+ cells were present, as well as an enrichment of regulatory T cells; and T cells expressing programmed death-1 (PD-1) and T cell Ig and mucin protein-3 (Tim-3), indicative of exhaustion, within the tumor microenvironment. Characterization of tumor-infiltrating B cells revealed clear evidence of antigen exposure, in that the cardinal features of an antigen-driven B cell response were present, including somatic mutation, clonal expansion, intraclonal variation and isotype switching. Collectively, our results point to an adaptive immune response occurring within the OSCC microenvironment, which may be sustained by the expression of specific antigens in the tumor.

The Lymphatic System in Disease Processes and Cancer Progression

Advances in our understanding of the structure and function of the lymphatic system have made it possible to identify its role in a variety of disease processes. Because it is involved not only in fluid homeostasis but also in immune cell trafficking, the lymphatic system can mediate and ultimately alter immune responses. Our rapidly increasing knowledge of the molecular control of the lymphatic system will inevitably lead to new and effective therapies for patients with lymphatic dysfunction. In this review, we discuss the molecular and physiological control of lymphatic vessel function and explore how the lymphatic system contributes to many disease processes, including cancer and lymphedema.

Interrogation of individual intratumoral B lymphocytes from lung cancer patients for molecular target discovery

Intratumoral B lymphocytes are an integral part of the lung tumor microenvironment. Interrogation of the antibodies they express may improve our understanding of the host response to cancer and could be useful in elucidating novel molecular targets. We used two strategies to explore the repertoire of intratumoral B cell antibodies. First, we cloned VH and VL genes from single intratumoral B lymphocytes isolated from one lung tumor, expressed the genes as recombinant mAbs, and used the mAbs to identify the cognate tumor antigens. The Igs derived from intratumoral B cells demonstrated class switching, with a mean VH mutation frequency of 4%. Although there was no evidence for clonal expansion, these data are consistent with antigen-driven somatic hypermutation. Individual recombinant antibodies were polyreactive, although one clone demonstrated preferential immunoreactivity with tropomyosin 4 (TPM4). We found that higher levels of TPM4 antibodies were more common in cancer patients, but measurement of TPM4 antibody levels was not a sensitive test for detecting cancer. Second, in an effort to focus our recombinant antibody expression efforts on those B cells that displayed evidence of clonal expansion driven by antigen stimulation, we performed deep sequencing of the Ig genes of B cells collected from seven different tumors. Deep sequencing demonstrated somatic hypermutation but no dominant clones. These strategies may be useful for the study of B cell antibody expression, although identification of a dominant clone and unique therapeutic targets may require extensive investigation.

Vaccination with Melanoma Helper Peptides Induces Antibody Responses Associated with Improved Overall Survival

PURPOSE

A melanoma vaccine incorporating six peptides designed to induce helper T-cell responses to melanoma antigens has induced Th1-dominant CD4(+) T-cell responses in most patients, and induced durable clinical responses or stable disease in 24% of evaluable patients. The present study tested whether this vaccine also induced antibody (Ab) responses to each peptide, and whether Ab responses were associated with T-cell responses and with clinical outcome.

EXPERIMENTAL DESIGN

Serum samples were studied from 35 patients with stage III-IV melanomas vaccinated with 6 melanoma helper peptides (6MHP). IgG Ab responses were measured by ELISA. Associations with immune response and overall survival were assessed by log-rank test and χ(2) analysis of Kaplan-Meier data.

RESULTS

Ab responses to 6MHP were detected by week 7 in 77% of patients, and increased to peak 6 weeks after the last vaccine and persisted to 6 months. Ab responses were induced most frequently to longer peptides. Of those with T-cell responses, 82% had early Ab responses. Survival was improved for patients with early Ab response (P = 0.0011) or with early T-cell response (P < 0.006), and was best for those with both Ab and T-cell responses (P = 0.0002).

CONCLUSIONS

Vaccination with helper peptides induced both Ab responses and T-cell responses, associated with favorable clinical outcome. Such immune responses may predict favorable clinical outcome to guide combination immunotherapy. Further studies are warranted to understand mechanisms of interaction of these Abs, T-cell responses, and tumor control.

Overcoming tumor-mediated immunosuppression

Mechanisms of tumor-mediated immunosuppression have been described for several solid and hematological tumors. Tumors inhibit immune responses by attraction of immunosuppressive lymphocytic populations, secretion of immunosuppressive cytokines or expression of surface molecules, which inhibit immune responses by induction of anergy or apoptosis in tumor-infiltrating lymphocytes. This tumor-mediated immunosuppression represents a major obstacle to many immunotherapeutic or conventional therapeutic approaches. In this review we discuss how tumor-mediated immunosuppression interferes with different immunotherapeutic approaches and then give an overview of strategies to overcome it. Particular emphasis is placed on agents or approaches already transferred into clinical settings. Finally the success of immune checkpoint inhibitors targeting CTLA-4 or the PD-1 pathway highlights the enormous therapeutic potential of an effective overcoming of tumor-mediated immunosuppression.

Characterization of tumor-associated B-cell subsets in patients with colorectal cancer

Purpose:

A precise understanding of the mechanisms by which human immune cell subsets affect tumor biology will be critical for successful treatment of cancer using immunotherapeutic approaches. Recent evidence suggests that B cells can both promote and inhibit the development and progression of tumors. The aim of this study was to characterize the composition of the B-cell infiltrates in colorectal cancers (CRC) in order to gain further insight into the role of B cells in CRC.

Experimental Design:

In this study we characterized B-cell subsets in primary tumors (n=38), metastases (n=6) and blood (n=46) of 51 patients with a diagnosis of CRC and blood of 10 healthy controls. B-cell subsets were analyzed by flow cytometry or immunohistochemistry.

Results:

Peripheral blood of CRC patients contained a higher percentage of memory B cells than that of age-matched healthy controls. Furthermore, the percentage of B cells within tumors was higher than that in the peripheral blood of CRC patients while metastases were typically devoid of tumor-infiltrating B cells. Tumor-associated B cells were enriched for activated and terminally differentiated B cells. Relevant proportions of regulatory B cells could only be detected in advanced cancer and metastases.

Conclusion:

B cells constitute a significant proportion of the immune infiltrate in CRC. The B-cell infiltrate of primary CRC is characterized by an accumulation of terminally differentiated memory B cells or plasma cells suggestive of a specific immune response against the tumor. However advanced tumors and metastases are also infiltrated by a considerable number of regulatory B cells.

The lymph node microenvironment and its role in the progression of metastatic cancer

Lymph nodes are initial sites for cancer metastasis in many solid tumors. However, their role in cancer progression is still not completely understood. Emerging evidence suggests that the lymph node microenvironment provides hospitable soil for the seeding and proliferation of cancer cells. Resident immune and stromal cells in the lymph node express and secrete molecules that may facilitate the survival of cancer cells in this organ. More comprehensive studies are warranted to fully understand the importance of the lymph node in tumor progression. Here, we will review the current knowledge of the role of the lymph node microenvironment in metastatic progression.

Identification of tumor-binding scFv derived from clonally related B cells in tumor and lymph node of a patient with breast cancer

The purpose of this study was to determine the clonal relationship between B cells within a breast cancer and the B cells in the tumor-draining lymph node (TDLN). We also determined the binding capacity of antibodies derived from these sources to autologous cancer and autologous noncancer breast tissue. Antibody clonality of B cells derived from tumor and lymph node was determined by analyzing heavy and light chain immunoglobulin sequences. The number of shared clonal groups observed between tumor and lymph node antibodies was significant for both heavy (p = 0.004) and light chain (p = 0.012) populations. Panning with phage-displayed single-chain variable fragment libraries derived from the tumor and lymph node B cells resulted in multiple antibodies that bound autologous tumor. Sequence analysis of enriched antibodies recovered after the third round of panning the tumor and TDLN libraries against autologous tumor lysates had a genetic relationship. These results indicate that B cells infiltrating a patient's breast cancer and B cells present in the tumor-draining lymph node are clonally and functionally related.

A simple and rapid protocol to non-enzymatically dissociate fresh human tissues for the analysis of infiltrating lymphocytes

The ability of malignant cells to evade the immune system, characterized by tumor escape from both innate and adaptive immune responses, is now accepted as an important hallmark of cancer. Our research on breast cancer focuses on the active role that tumor infiltrating lymphocytes play in tumor progression and patient outcome. Toward this goal, we developed a methodology for the rapid isolation of intact lymphoid cells from normal and abnormal tissues in an effort to evaluate them proximate to their native state. Homogenates prepared using a mechanical dissociator show both increased viability and cell recovery while preserving surface receptor expression compared to enzyme-digested tissues. Furthermore, enzymatic digestion of the remaining insoluble material did not recover additional CD45(+) cells indicating that quantitative and qualitative measurements in the primary homogenate likely genuinely reflect infiltrating subpopulations in the tissue fragment. The lymphoid cells in these homogenates can be easily characterized using immunological (phenotype, proliferation, etc.) or molecular (DNA, RNA and/or protein) approaches. CD45(+) cells can also be used for subpopulation purification, in vitro expansion or cryopreservation. An additional benefit of this approach is that the primary tissue supernatant from the homogenates can be used to characterize and compare cytokines, chemokines, immunoglobulins and antigens present in normal and malignant tissues. This protocol functions extremely well for human breast tissues and should be applicable to a wide variety of normal and abnormal tissues.

Microenvironment of tumor-draining lymph nodes: opportunities for liposome-based targeted therapy

The World Health Organization (WHO) recently reported that the total number of global cancer cases in 2013 reached 14 million, a 10% rise since 2008, while the total number of cancer deaths reached 8.2 million, a 5.2% increase since 2008. Metastasis is the major cause of death from cancer, accounting for 90% of all cancer related deaths. Tumor-draining lymph nodes (TDLN), the sentinel nodes, are the first organs of metastasis in several types of cancers. The extent of metastasis in the TDLN is often used in disease staging and prognosis evaluation in cancer patients. Here, we describe the microenvironment of the TDLN and review the recent literature on liposome-based therapies directed to immune cells within the TDLN with the intent to target cancer cells.

B cell-regulated immune responses in tumor models and cancer patients

The essential role played by T cells in anticancer immunity is widely accepted. The immunosuppressive functions of regulatory T cells are central for tumor progression and have been endowed with a robust predictive value. Increasing evidence indicates that also B cells have a crucial part in the regulation of T-cell responses against tumors. Although experiments reporting the production of natural antitumor antibodies and the induction of cytotoxic immune responses have revealed a tumor-protective function for B cells, other findings suggest that B cells may also exert tumor-promoting functions, resulting in a controversial picture. Here, we review recent evidence on the interactions between B and T cells in murine models and cancer patients and their implications for cancer immunology.

Manipulation of tumour-infiltrating B cells and tertiary lymphoid structures: a novel anti-cancer treatment avenue?

Combining different standard therapies with immunotherapy for the treatment of solid tumours has proven to yield a greater clinical benefit than when each is applied separately; however, the percentage of complete responses is still far from optimal, and there is an urgent need for improved treatment modalities. The latest literature data suggest that tertiary lymphoid structures (TLS), previously shown to correlate with the severity of autoimmune diseases or transplant rejection, are also formed in tumours, have a significant beneficial effect on survival and might reflect the generation of an effective immune response in close proximity to the tumour. Thus, the facilitation of TLS formation in tumour stroma could provide novel means to improve the efficiency of immunotherapy and other standard therapies. However, little is known about the mechanisms regulating the formation of tumour-associated TLS. Studies of chronic inflammatory diseases and transplant rejection have demonstrated that TLS formation and/or function requires the presence of B cells. Additionally, the infiltration of B cells into the tumour stroma has been demonstrated to be a significant prognostic factor for improved survival in different human tumours. This suggests that B cells could play a beneficial role in anti-tumour immune response not only in the context of antibody production, antigen presentation and Th1-promoting cytokine production, but also TLS formation. This review focuses on the latest discoveries in tumour-infiltrating B cell functions, their role in TLS formation and relevance in human tumour control, revealing novel opportunities to improve cancer therapies.

Signaling between tumor cells and the host bone marrow microenvironment

Tumor cells with high skeletal homing affinity express numerous cell surface receptors that bind ligands produced in bone. Upon arrival, these cells survive in the host environment, encompassed in close proximity to bone marrow cells. Interactions between tumor cells and cells of the host microenvironment are essential to not only tumor cell survival but also their activation and proliferation into environment-modifying tumors. Through the production of RANKL, PTHrP, cytokines, and integrins, activated tumor cells stimulate osteoclastogenesis, enhance bone resorption, and subsequently release matrix-bound proteins that further promote tumor growth and bone resorption. In addition, alterations in the TGF-β/BMP and Wnt signaling pathways via tumor cell growth can either stimulate or suppress osteoblastic bone formation and function, leading to sclerotic or lytic bone disease, respectively. Hence, the presence of tumor cells in bone dysregulates bone remodeling, dramatically impairing skeletal integrity. Furthermore, through complex mechanisms, cells of the immune system interact with tumor cells to further impact bone remodeling. Lastly, with alterations in bone cell activity, the environment is permissive to promoting tumor growth further, suggesting an interdependence between tumor cells and bone cells in metastatic bone disease and multiple myeloma.