Tumors promote altered maturation and early apoptosis of monocyte-derived dendritic cells

Effectiveness and safety of COVID-19 vaccines in patients with oncological diseases: State-of-the-art

Although the coronavirus disease 2019 (COVID-19) pandemic was declared to be no longer “a public health emergency of international concern” with its wide range of clinical manifestations and late complications, severe acute respiratory syndrome coronavirus 2 infection proved to be a serious threat, especially to the elderly and patients with comorbidities. Patients with oncologic diseases are vulnerable to severe infection and death. Indeed, patients with oncohematological diseases have a higher risk of severe COVID-19 and impaired post-vaccination immunity. Unfortunately, cancer patients are usually excluded from vaccine trials and investigations of post-vaccinal immune responses and the effectiveness of the vaccines. We aimed to elucidate to what extent patients with cancer are at increased risk of developing severe COVID-19 and what is their overall case fatality rate. We also present the current concept and evidence on the effectiveness and safety of COVID-19 vaccines, including boosters, in oncology patients. In conclusion, despite the considerably higher mortality in the cancer patient group than the general population, countries with high vaccination rates have demonstrated trends toward improved survival of cancer patients early and late in the pandemic.

Immunotherapy in Elderly Patients Affected by Non-Small Cell Lung Cancer: A Narrative Review

Lung cancer is the leading cause of cancer-related deaths worldwide. Non-small cell lung cancer (NSCLC) accounts for approximately 80% of all lung cancers, and most NSCLC is diagnosed in the advanced stage. The advent of immune check point inhibitors (ICIs) changed the therapeutic scenario both in metastatic disease (in first and subsequent lines) and earlier settings. Comorbidities, reduced organ function, cognitive deterioration, and social impairment give reasons for a greater probability of adverse events, making the treatment of elderly patients challenging. The reduced toxicity of ICIs compared to standard chemotherapy makes this approach attractive in this population. The effectiveness of ICIs varies according to age, and patients older than 75 years may benefit less than younger patients. This may be related to the so-called immunosenescence, a phenomenon that refers to the reduced activity of immunity with older age. Elders are often under-represented in clinical trials, even if they are a large part of the patients in a clinical practice. In this review, we aim to explore the biological aspects of immunosenescence and to report and analyze the most relevant and recent literature findings on the role of immunotherapy in elderly patients with NSCLC.

Correlation between hypoxia and HGF/c-MET expression in the management of pancreatic cancer

Pancreatic cancer (PC) is very deadly and difficult to treat. The presence of hypoxia has been shown to increase the probability of cancer developing and spreading. Pancreatic ductal adenocarcinoma (PDAC/PC) has traditionally viewed a highly lethal form of cancer due to its high occurrence of early metastases. Desmoplasia/stroma is often thick and collagenous, with pancreatic stellate cells as the primary source (PSCs). Cancer cells and other stromal cells interact with PSCs, promoting disease development. The hepatocyte growth factor (HGF)/c-MET pathway have been proposed as a growth factor mechanism mediating this interaction. Human growth factor (HGF) is secreted by pancreatic stellate cells (PSCs), and its receptor, c-MET, is generated by pancreatic cancer cells and endothelial cells. Hypoxia is frequent in malignant tumors, particularly pancreatic (PC). Hypoxia results from limitless tumor development and promotes survival, progression, and invasion. Hypoxic is becoming a critical driver and therapeutic target of pancreatic cancer as its hypoxia microenvironment is defined. Recent breakthroughs in cancer biology show that hypoxia promotes tumor proliferation, aggressiveness, and therapeutic resistance. Hypoxia-inducible factors (HIFs) stabilize hypoxia signaling. Hypoxia cMet is a key component of pancreatic tumor microenvironments, which also have a fibrotic response, that hypoxia, promotes and modulates. c-Met is a tyrosine-protein kinase. As describe it simply, the MET gene in humans' codes for a protein called hepatocyte growth factor receptor (HGFR). Most cancerous tumors and pancreatic cancer in particular, suffer from a lack of oxygen (PC). Due to unrestrained tumor development, hypoxia develops, actively contributing to tumor survival, progression, and invasion. As the processes by which hypoxia signaling promotes invasion and metastasis become clear, c-MET has emerged as an important determinant of pancreatic cancer malignancy and a potential pharmacological target. This manuscript provides the most current findings on the role of hypoxia and HGF/c-MET expression in the treatment of pancreatic cancer.

Dendritic Cells: The Long and Evolving Road towards Successful Targetability in Cancer

Dendritic cells (DCs) are a unique myeloid cell lineage that play a central role in the priming of the adaptive immune response. As such, they are an attractive target for immune oncology based therapeutic approaches. However, targeting these cells has proven challenging with many studies proving inconclusive or of no benefit in a clinical trial setting. In this review, we highlight the known and unknown about this rare but powerful immune cell. As technologies have expanded our understanding of the complexity of DC development, subsets and response features, we are now left to apply this knowledge to the design of new therapeutic strategies in cancer. We propose that utilization of these technologies through a multiomics approach will allow for an improved directed targeting of DCs in a clinical trial setting. In addition, the DC research community should consider a consensus on subset nomenclature to distinguish new subsets from functional or phenotypic changes in response to their environment.

The Therapeutic Potential of Tackling Tumor-Induced Dendritic Cell Dysfunction in Colorectal Cancer

Colorectal cancer (CRC) is the third most diagnosed malignancy and the second leading cause of cancer-related deaths worldwide. Locally advanced and metastatic disease exhibit resistance to therapy and are prone to recurrence. Despite significant advances in standard of care and targeted (immuno)therapies, the treatment effects in metastatic CRC patients have been modest. Untreatable cancer metastasis accounts for poor prognosis and most CRC deaths. The generation of a strong immunosuppressive tumor microenvironment (TME) by CRC constitutes a major hurdle for tumor clearance by the immune system. Dendritic cells (DCs), often impaired in the TME, play a critical role in the initiation and amplification of anti-tumor immune responses. Evidence suggests that tumor-mediated DC dysfunction is decisive for tumor growth and metastasis initiation, as well as for the success of immunotherapies. Unravelling and understanding the complex crosstalk between CRC and DCs holds promise for identifying key mechanisms involved in tumor progression and spread that can be exploited for therapy. The main goal of this review is to provide an overview of the current knowledge on the impact of CRC-driven immunosuppression on DCs phenotype and functionality, and its significance for disease progression, patient prognosis, and treatment response. Moreover, present knowledge gaps will be highlighted as promising opportunities to further understand and therapeutically target DC dysfunction in CRC. Given the complexity and heterogeneity of CRC, future research will benefit from the use of patient-derived material and the development of in vitro organoid-based co-culture systems to model and study DCs within the CRC TME.

Involvement of Alarmins in the Pathogenesis and Progression of Multiple Myeloma

OBJECTIVE

Multiple Myeloma (MM) is a haematological disease resulting from the neoplastic transformation of plasma cells. The uncontrolled growth of plasma cells in the bone marrow and the delivery of several cytokines causes bone erosion that often does not regress, even in the event of disease remission. MM is characterised by a multi-step evolutionary path, which starts with an early asymptomatic stage defined as monoclonal gammopathy of undetermined significance (MGUS) evolving to overt disease.

DATA SOURCES AND STUDY SELECTION

We have selected scientific publications on the specific topics "alarmis, MGUS, and MM", drawing from PubMed. The keywords we used were alarmines, MGUS, MM, and immune system.

RESULTS

The analysis confirms the pivotal role of molecules such as high-mobility group box-1, heat shock proteins, and S100 proteins in the induction of neoangiogenesis, which represents a milestone in the negative evolution of MM as well as other haematological and non-haematological tumours.

CONCLUSIONS

Modulation of the host immune system and the inhibition of neoangiogenesis may represent the therapeutic target for the treatment of MM that is capable of promoting better survival and reducing the risk of RRMM.

Metabolic reprogramming due to hypoxia in pancreatic cancer: Implications for tumor formation, immunity, and more

Hypoxia is a common phenomenon in most malignant tumors, especially in pancreatic cancer (PC). Hypoxia is the result of unlimited tumor growth and plays an active role in promoting tumor survival, progression, and invasion. As the part of the hypoxia microenvironment in PC is gradually clarified, hypoxia is becoming a key determinant and an important therapeutic target of pancreatic cancer. To adapt to the severe hypoxia environment, cells have changed their metabolic phenotypes to maintain their survival and proliferation. Enhanced glycolysis is the most prominent feature of cancer cells' metabolic reprogramming in response to hypoxia. It provides the energy source for hypoxic cancer cells (although it provides less than oxidative phosphorylation) and produces metabolites that can be absorbed and utilized by normoxic cancer cells. In addition, the uptake of glutamine and fatty acids by hypoxic cancer cells is also increased, which is also conducive to tumor progression. Their metabolites are pooled in the hexosamine biosynthesis pathway (HBP). As a nutrition sensor, HBP, in turn, can coordinate glucose and glutamine metabolism. Its end product, UDP-GlcNAc, is the substrate of protein post-translational modification (PTM) involved in various signaling pathways supporting tumor progression. Adaptive metabolic changes of cancer cells promote their survival and affect tumor immune cells in the tumor microenvironment (TME), which contributes to tumor immunosuppressive microenvironment and induces tumor immunotherapy resistance. Here, we summarize the hypoxic microenvironment, its effect on metabolic reprogramming, and its contribution to immunotherapy resistance in pancreatic cancer.

Understanding the Role of Innate Immune Cells and Identifying Genes in Breast Cancer Microenvironment

The innate immune system is the first line of defense against invading pathogens and has a major role in clearing transformed cells, besides its essential role in activating the adaptive immune system. Macrophages, dendritic cells, NK cells, and granulocytes are part of the innate immune system that accumulate in the tumor microenvironment such as breast cancer. These cells induce inflammation in situ by secreting cytokines and chemokines that promote tumor growth and progression, in addition to orchestrating the activities of other immune cells. In breast cancer microenvironment, innate immune cells are skewed towards immunosuppression that may lead to tumor evasion. However, the mechanisms by which immune cells could interact with breast cancer cells are complex and not fully understood. Therefore, the importance of the mammary tumor microenvironment in the development, growth, and progression of cancer is widely recognized. With the advances of using bioinformatics and analyzing data from gene banks, several genes involved in NK cells of breast cancer individuals have been identified. In this review, we discuss the activities of certain genes involved in the cross-talk among NK cells and breast cancer. Consequently, altering tumor immune microenvironment can make breast tumors more responsive to immunotherapy.

Tumor-derived extracellular vesicles: Regulators of tumor microenvironment and the enlightenment in tumor therapy

In recent decades, extracellular vesicles (EVs) have been proven to establish an important bridge of communication between cells or cells and their microenvironment. It is well known that EVs play crucial roles in many human diseases, especially in tumors. Tumor-derived EVs (TEVs) are not only involved in epithelial-mesenchymal transition and extracellular matrix remodeling to promote the invasion and metastasis, but also contribute to the suppression of antitumor immune responses by carrying different inhibitory molecules. In this review, we mainly discuss the effects of TEVs on the remodeling of tumor microenvironment through immune and non-immune associated mechanisms. We summarize the latest studies about utilizing EVs in clinical diagnosis and therapeutic drug delivery as well. In addition, the perspective of tumor therapy by targeting EVs is discussed in this review.

Suggested Case of Langerhans Cell Histiocytosis in a Cretaceous dinosaur

Susceptibility to diseases is common to humans and dinosaurs. Since much of the biological history of every living creature is shaped by its diseases, recognizing them in fossilized bone can furnish us with important information on dinosaurs' physiology and anatomy, as well as on their daily activities and surrounding environment. In the present study, we examined the vertebrae of two humans from skeletal collections with Langerhans Cell Histiocytosis (LCH), a benign osteolytic tumor-like disorder involving mainly the skeleton; they were diagnosed in life, along with two hadrosaur vertebrae with an apparent lesion. Macroscopic and microscopic analyses of the hadrosaur vertebrae were compared to human LCH and to other pathologies observed via an extensive pathological survey of a human skeletal collection, as well as a three-dimensional reconstruction of the lesion and its associated blood vessels from a µCT scan. The hadrosaur pathology findings were indistinguishable from those of humans with LCH, supporting that diagnosis. This report suggests that hadrosaurids had suffered from larger variety of pathologies than previously reported. Furthermore, it seems that LCH may be independent of phylogeny.

Combined effect of silver nanoparticles and aluminium chloride, butylparaben or diethylphthalate on the malignancy of MDA-MB-231 breast cancer cells and tumor-specific immune responses of human macrophages and monocyte-derived dendritic cells

The aim of this study was to assess whether silver nanoparticles (AgNP) or selected cosmetic ingredients may modify functions of various immunocompetent cell populations. To this end, the effect of two AgNP (size of 15 nm or 45 nm), alone and in combination with aluminium chloride, butyl paraben, di-n-butyl phthalate or diethyl phthalate was assessed on: (1) migration and invasion of MDA-MB-231 human breast cancer cells; (2) M1/M2 polarization of phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 macrophages (M0) and (3) activation/maturation of monocyte-derived dendritic cells (DCs). The results of this study showed that neither any of the test chemicals alone nor the mixtures significantly changed the migration or invasion ability of MDA-MB-231 cells following, both 72-h and 21-day exposure. Analysis of the expression of marker genes for both M1 (IL-1B, CXCL9, TNF) and M2 (DCSIGN, MRC1) polarization revealed that the chemicals/mixtures did not activate M1/M2 differentiation of the M0 macrophages. In addition, no significant changes were observed in the expression of CD86, HLA-DR and CD54 surface markers and phagocytic activity of DCs following 48-h exposure to AgNP alone or in combination with test compounds. Our study suggests that AgNP alone or in combination with tested cosmetic ingredients do not alter function of immunocompetent cells studied.

mTOR Inhibitors Can Enhance the Anti-Tumor Effects of DNA Vaccines through Modulating Dendritic Cell Function in the Tumor Microenvironment

The life span of dendritic cells (DCs) can become short following induced activation, which is associated with metabolic transition due to the regulation of mechanistic target of rapamycin (mTOR). The purpose of this study was to investigate the potential of inhibiting mTOR to modulate DC functions for elevating the anti-tumor effects of DNA vaccines. Therefore, the influences of various inhibitors of mTOR (mTORi) on the expressions of DC maturation markers, the abilities of antigen presenting and processing of BMM-derived DCs and the tumor killing effects of E7-specific CD8⁺ T lymphocytes activated by BMM-derived DCs were in vitro examined. The anti-tumor effects of connective tissue growth factor (CTGF)/E7 DNA vaccine and/or mTORi were also in vivo analyzed. In our study, suppressive effects of mTORi on the DC maturation markers expressed on BMMCs could be reversed. The mTORi-treated mature BMM-derived DCs tended to be non-apoptotic. These mTORi-treated BMM-derived DCs could have better antigen presenting and processing abilities. The E7-specific cytotoxic CD8+ T lymphocytes could have more potent tumoricidal activity following activation of mTORi-treated BMM-derived DCs. For tumor-bearing mice, those treated with CTGF/E7 DNA vaccine and mTORi indeed can have higher percentages of mature DCs in the TME, better disease control and longer survivals. Consequently, application of mTORi can be a pharmacological approach for temporally increasing life span, antigen presenting and antigen processing of DCs to strengthen the therapeutic outcome of cancer immunotherapy.

Multiple Myeloma: What Do We Do About Immunodeficiency?

Multiple myeloma (MM) is an incurable hematological malignancy. Immunodeficiency results in the incapability of immunity to eradicate both tumor cells and pathogens. Immunotherapies along with antibiotics and other anti-infectious agents are applied as substitutes for immunity in MM. Immunotherapies including monoclonal antibodies, immune checkpoints inhibitors, affinity- enhanced T cells, chimeric antigen receptor T cells and dendritic cell vaccines are revolutionizing MM treatment. By suppressing the pro-inflammatory milieu and pathogens, prophylactic and therapeutic antibiotics represent anti-tumor and anti-infection properties. It is expected that deeper understanding of infection, immunity and tumor physio-pathologies in MM will accelerate the optimization of combined therapies, thus improving prognosis in MM.

Human Dendritic Cells: Their Heterogeneity and Clinical Application Potential in Cancer Immunotherapy

Dendritic cells (DC) are professional antigen presenting cells, uniquely able to induce naïve T cell activation and effector differentiation. They are, likewise, involved in the induction and maintenance of immune tolerance in homeostatic conditions. Their phenotypic and functional heterogeneity points to their great plasticity and ability to modulate, according to their microenvironment, the acquired immune response and, at the same time, makes their precise classification complex and frequently subject to reviews and improvement. This review will present general aspects of the DC physiology and classification and will address their potential and actual uses in the management of human disease, more specifically cancer, as therapeutic and monitoring tools. New combination treatments with the participation of DC will be also discussed.

Stromal cells in breast cancer as a potential therapeutic target

Breast cancer in the United States is the second most commonly diagnosed cancer in women. About 1 in 8 women will develop invasive breast cancer over the course of her lifetime and breast cancer remains the second leading cause of cancer-related death. In pursuit of novel therapeutic strategies, researchers have examined the tumor microenvironment as a potential anti-cancer target. In addition to neoplastic cells, the tumor microenvironment is composed of several critical normal cell types, including fibroblasts, vascular and lymph endothelial cells, osteoclasts, adipocytes, and immune cells. These cells have important roles in healthy tissue stasis, which frequently are altered in tumors. Indeed, tumor-associated stromal cells often contribute to tumorigenesis, tumor progression, and metastasis. Consequently, these host cells may serve as a possible target in anti-tumor and anti-metastatic therapeutic strategies. Targeting the tumor associated host cells offers the benefit that such cells do not mutate and develop resistance in response to treatment, a major cause of failure in cancer therapeutics targeting neoplastic cells. This review discusses the role of host cells in the tumor microenvironment during tumorigenesis, progression, and metastasis, and provides an overview of recent developments in targeting these cell populations to enhance cancer therapy efficacy.

Immunosuppressive effect of bladder cancer on function of dendritic cells involving of Jak2/STAT3 pathway

Function of dendritic cells (DCs) is impaired by some cancer cells. However, the effect of bladder cancer cell (BCC) on phenotype and function of DCs remains unclear. In this study, healthy human peripheral blood mononuclear cells (PBMCs) derived DCs were co-cultured with BCC pumc-91 and adriamycin-resistant pumc-91/ADM. The expression of DC markers and costimulatory molecules decreased after co-culture. Co-cultured DCs rapidly underwent apoptosis, and had a declined capability to produce IL-8 and RANTES. Furthermore, co-cultured DCs showed impaired allogeneic T cell proliferation and T cell-derived cytokine secretion. Finally, AG490, a Jak2/STAT3 inhibitor, restored the expression of DC markers and costimulatory molecules. Of note, compared with control DCs, DCs co-cultured with pumc-91 produced more IP-10; DCs co-cultured with pumc-91/ADM secreted more MIG. Taken together, these results suggest BCC may inhibit maturation and function of DCs involving of Jak2/STAT3 pathway, and there may be different mechanisms by which adriamycin-resistant BCC restrains DC function in antitumor immune response.

STING, DCs and the link between innate and adaptive tumor immunity

Cancer and the immune system are intimately related. Much of the bulk of tumors is comprised of stromal leukocytes with immune functions, which serve to both promote and inhibit tumor growth, invasion and metastasis. The T lymphocytes of the adaptive immune system are essential for tumor immunity, and these T cells are generated by cross-priming against tumor associated antigens. Dendritic cells (DCs) are essential in this process, serving as the cellular link between innate and adaptive immunity. As a prerequisite for priming of adaptive immune responses, DCs must take up tumor antigens, process them and present them in the context of the major histocompatibility complex (MHC). DCs also serve as sensors of innate activation signals from cancer that are necessary for their activation and effective priming of cancer specific T cells. Here we discuss the role of DCs in the sensing of cancer and in priming the adaptive response against tumors. Furthermore, we present the essential role of the Stimulator of Interferon Genes (STING) signaling pathway in producing type I interferons (IFNs) that are essential in this process.

Tyrosine kinase inhibitors reprogramming immunity in renal cell carcinoma: rethinking cancer immunotherapy

The immune system regulates angiogenesis in cancer by way of both pro- and antiangiogenic activities. A bidirectional link between angiogenesis and the immune system has been clearly demonstrated. Most antiangiogenic molecules do not inhibit only VEGF signaling pathways but also other pathways which may affect immune system. Understanding of the role of these pathways in the regulation of immunosuppressive mechanisms by way of specific inhibitors is growing. Renal cell carcinoma (RCC) is an immunogenic tumor in which angiogenesis and immunosuppression work hand in hand, and its growth is associated with impaired antitumor immunity. Given the antitumor activity of selected TKIs in metastatic RCC (mRCC), it seems relevant to assess their effect on the immune system. The confirmation that TKIs improve cell cytokine response in mRCC provides a basis for the rational combination and sequential treatment of TKIs and immunotherapy.

Sensitivity of Dendritic Cells to Microenvironment Signals

Dendritic cells are antigen-presenting cells capable of either activating the immune response or inducing and maintaining immune tolerance. They do this by integrating stimuli from the environment and changing their functional status as a result of plasticity. The modifications suffered by these cells have consequences in the way the organism may respond. In the present work two opposing situations known to affect dendritic cells are analyzed: tumor growth, leading to a microenvironment that favors the induction of a tolerogenic profile, and organ transplantation, which leads to a proinflammatory profile. Lessons learned from these situations may help to understand the mechanisms of modulation resulting not only from the above circumstances, but also from other pathologies.

Dendritic Cells in Oncolytic Virus-Based Anti-Cancer Therapy

Dendritic cells (DCs) are specialized antigen-presenting cells that have a notable role in the initiation and regulation of innate and adaptive immune responses. In the context of cancer, appropriately activated DCs can induce anti-tumor immunity by activating innate immune cells and tumor-specific lymphocytes that target cancer cells. However, the tumor microenvironment (TME) imposes different mechanisms that facilitate the impairment of DC functions, such as inefficient antigen presentation or polarization into immunosuppressive DCs. These tumor-associated DCs thus fail to initiate tumor-specific immunity, and indirectly support tumor progression. Hence, there is increasing interest in identifying interventions that can overturn DC impairment within the TME. Many reports thus far have studied oncolytic viruses (OVs), viruses that preferentially target and kill cancer cells, for their capacity to enhance DC-mediated anti-tumor effects. Herein, we describe the general characteristics of DCs, focusing on their role in innate and adaptive immunity in the context of the TME. We also examine how DC-OV interaction affects DC recruitment, OV delivery, and anti-tumor immunity activation. Understanding these roles of DCs in the TME and OV infection is critical in devising strategies to further harness the anti-tumor effects of both DCs and OVs, ultimately enhancing the efficacy of OV-based oncotherapy.

Cancer vaccines

Cancer vaccines are designed to promote tumor specific immune responses, particularly cytotoxic CD8 positive T cells that are specific to tumor antigens. The earliest vaccines, which were developed in 1994-95, tested non-mutated, shared tumor associated antigens that had been shown to be immunogenic and capable of inducing clinical responses in a minority of people with late stage cancer. Technological developments in the past few years have enabled the investigation of vaccines that target mutated antigens that are patient specific. Several platforms for cancer vaccination are being tested, including peptides, proteins, antigen presenting cells, tumor cells, and viral vectors. Standard of care treatments, such as surgery and ablation, chemotherapy, and radiotherapy, can also induce antitumor immunity, thereby having cancer vaccine effects. The monitoring of patients' immune responses at baseline and after standard of care treatment is shedding light on immune biomarkers. Combination therapies are being tested in clinical trials and are likely to be the best approach to improving patient outcomes.

Mesothelioma tumor cells modulate dendritic cell lipid content, phenotype and function

Dendritic cells (DCs) play an important role in the generation of anti-cancer immune responses, however there is evidence that DCs in cancer patients are dysfunctional. Lipid accumulation driven by tumor-derived factors has recently been shown to contribute to DC dysfunction in several human cancers, but has not yet been examined in mesothelioma. This study investigated if mesothelioma tumor cells and/or their secreted factors promote increases in DC lipid content and modulate DC function. Human monocyte-derived DCs (MoDCs) were exposed to human mesothelioma tumor cells and tumor-derived factors in the presence or absence of lipoproteins. The data showed that immature MoDCs exposed to mesothelioma cells or factors contained increased lipid levels relative to control DCs. Lipid accumulation was associated with reduced antigen processing ability (measured using a DQ OVA assay), upregulation of the co-stimulatory molecule, CD86, and production of the tolerogenic cytokine, IL-10. Increases in DC lipid content were further enhanced by co-exposure to mesothelioma-derived factors and triglyceride-rich lipoproteins, but not low-density lipoproteins. In vivo studies using a murine mesothelioma model showed that the lipid content of tumor-infiltrating CD4+ CD8α- DCs, CD4- CD8α- DCs DCs and plasmacytoid DCs increased with tumor progression. Moreover, increasing tumor burden was associated with reduced proliferation of tumor-antigen-specific CD8+ T cells in tumor-draining lymph nodes. This study shows that mesothelioma promotes DC lipid acquisition, which is associated with altered activation status and reduced capacity to process and present antigens, which may impair the ability of DCs to generate effective anti mesothelioma T cell responses.

Complex role for the immune system in initiation and progression of pancreatic cancer

The immune system plays a complex role in the development and progression of pancreatic cancer. Inflammation can promote the formation of premalignant lesions and accelerate pancreatic cancer development. Conversely, pancreatic cancer is characterized by an immunosuppressive environment, which is thought to promote tumor progression and invasion. Here we review the current literature describing the role of the immune response in the progressive development of pancreatic cancer, with a focus on the mechanisms that drive recruitment and activation of immune cells at the tumor site, and our current understanding of the function of the immune cell types at the tumor. Recent clinical and preclinical data are reviewed, detailing the involvement of the immune response in pancreatitis and pancreatic cancer, including the role of specific cytokines and implications for disease outcome. Acute pancreatitis is characterized by a predominantly innate immune response, while chronic pancreatitis elicits an immune response that involves both innate and adaptive immune cells, and often results in profound systemic immune-suppression. Pancreatic adenocarcinoma is characterized by marked immune dysfunction driven by immunosuppressive cell types, tumor-promoting immune cells, and defective or absent inflammatory cells. Recent studies reveal that immune cells interact with cancer stem cells and tumor stromal cells, and these interactions have an impact on development and progression of pancreatic ductal adenocarcinoma (PDAC). Finally, current PDAC therapies are reviewed and the potential for harnessing the actions of the immune response to assist in targeting pancreatic cancer using immunotherapy is discussed.

Induction of suppressive phenotype in monocyte-derived dendritic cells by leukemic cell products and IL-1β

Professional antigen-presenting cells, dendritic cells (DCs) play an important role in controlling tumors. It is known that solid tumor cell products inhibit DC differentiation. Recently a similar effect produced by leukemic cell products has been demonstrated. In this case, leukemic cell products induced the secretion of IL-1β by monocytes undergoing differentiation. The aim of the present work was to characterize and to compare the development of monocyte-derived DCs under the influence of leukemic cell products (K562 supernatant) or exogenous IL-1β. It became clear that leukemic cell products and IL-1β differentially modulate some of the parameters studied on monocytes stimulated to differentiate into DCs. In the presence of K562 supernatant, the expression of the macrophage markers CD16 and CD68 were higher than in immature DCs control. Contrasting with IL-1β, leukemic cell products possibly favor the development of cells with macrophage markers. In addition, CD80 and CD83 expressions were also higher in the presence of tumor supernatant whereas HLA-DR was lower. In the presence of IL-1β, only CD80 was increased. Furthermore, it was observed that when monocytes were induced to differentiate into DCs in the presence of tumor supernatant and then activated, they expressed less CD80 and CD83 than activated DCs control. A reduced expression of CD83 following activation was also seen in cells differentiated with IL-1β. TGF-β and VEGF were found in the tumor supernatants. Moreover, the exposure to tumor supernatant or IL-1β stimulated IL-10 production while decreased IL-12 production by activated DCs. Finally, these results suggest that the addition of products released by leukemic cells or, more discreetly, the addition of IL-1β affects DC differentiation, inducing a suppressive phenotype.

Induction of dendritic cell maturation in the skin microenvironment by soluble factors derived from colon carcinoma

Autologous tumor cell-based vaccines provide a wide range of tumor antigens and personalized neo-epitopes based on individual tumors' unique antigenic mutanome signatures. However, tumor-derived factors may hamper in situ maturation of dendritic cells (DC) and thus interfere with the generation of effective anti-tumor immunity. As the skin is a preferred site for tumor vaccine delivery, we investigated the influence of primary colon carcinoma-derived soluble factors on the maturation state of migrating DC in a human skin explant model. Primary tumor-derived supernatants (TDSN) enhanced the phenotypic maturation state of skin-emigrated DC, resulting in an increased T-cell stimulatory ability in an allogeneic mixed leukocyte response. In case of monocyte-derived DC a similar TDSN-induced maturation induction was found to entirely depend on cyclooxygenase (COX)-regulated prostaglandins. In contrast, the increase in skin-emigrated DC maturation was completely prostaglandin-independent, as evidenced by the inability of the COX inhibitor indomethacin to abrogate this TDSN-induced effect. Although TDSN conditioning affected a drop in IL-12p70 release by the skin-emigrated DC and induced a predominant Th17/Th22 transcriptional profile in subsequently stimulated T-cells, Th cell subset differentiation, as assessed by intracellular cytokine expression upon polyclonal priming and re-stimulation, was not affected. Comparative analysis of phenotypic and transcriptional profiles suggests that the observed maturational effects in skin-derived DC may have been induced by tumor-derived GM-CSF. In conclusion, soluble factors derived from whole-cell colon tumor vaccines will not negatively impact DC migration and maturation in human skin, but rather induce DC maturation that will facilitate the priming of a poly-functional Th cell response.

The immunostimulatory effects of retinoblastoma cell supernatant on dendritic cells

Dendritic cells (DCs) are crucial for the induction and maintenance of tumor-specific immune responses. Studies have shown that tumor-associated DCs are immunosuppressed in some human tumors. However, phenotype and function of DCs in retinoblastoma (RB) remain unclear. RB cell supernatant (RBcs) was used to treat DCs in vitro to explore the effect of RB cells on DCs. DCs were generated from peripheral blood mononuclear cells of healthy donors. On day 5 of culture, DCs were treated with RBcs for 24 h, and then purified using magnetic beads. The maturation of DCs was induced by TNF-α or LPS. After treatment with RBcs, expression of co-stimulatory molecules CD80 and CD86 was elevated in DCs, accompanied by increased production of IL-12p70, TNF-α, IL-6, IL-1β, and IL-8 but decreased production of IL-10. RBcs neither inhibited DC maturation nor promoted DC apoptosis. Moreover, RBcs-exposed DCs stimulated allogenetic T cell proliferation and T cell-derived cytokine production. These results indicate that RBcs can improve DCs’ antigen presenting function and capability to activate T cells, suggesting that RB cells may have an immunostimulatory effect on DCs, and DC-based immunotherapy may be adopted in the treatment of RB.

Blood dendritic cells: "canary in the coal mine" to predict chronic inflammatory disease?

The majority of risk factors for chronic inflammatory diseases are unknown. This makes personalized medicine for assessment, prognosis, and choice of therapy very difficult. It is becoming increasingly clear, however, that low-grade subclinical infections may be an underlying cause of many chronic inflammatory diseases and thus may contribute to secondary outcomes (e.g., cancer). Many diseases are now categorized as inflammatory-mediated diseases that stem from a dysregulation in host immunity. There is a growing need to study the links between low-grade infections, the immune responses they elicit, and how this impacts overall health. One such link explored in detail here is the extreme sensitivity of myeloid dendritic cells (mDCs) in peripheral blood to chronic low-grade infections and the role that these mDCs play in arbitrating the resulting immune responses. We find that emerging evidence supports a role for pathogen-induced mDCs in chronic inflammation leading to increased risk of secondary clinical disease. The mDCs that are elevated in the blood as a result of low-grade bacteremia often do not trigger a productive immune response, but can disseminate the pathogen throughout the host. This aberrant trafficking of mDCs can accelerate systemic inflammatory disease progression. Conversely, restoration of dendritic cell homeostasis may aid in pathogen elimination and minimize dissemination. Thus it would seem prudent when assessing chronic inflammatory disease risk to consider blood mDC numbers, and the microbial content (microbiome) and activation state of these mDCs. These may provide important clues (“the canary in the coal mine”) of high inflammatory disease risk. This will facilitate development of novel immunotherapies to eliminate such smoldering infections in atherosclerosis, cancer, rheumatoid arthritis, and pre-eclampsia.

Cellular and molecular mechanisms in cancer immune escape: a comprehensive review

Immune escape is the final phase of cancer immunoediting process wherein cancer modulates our immune system to escape from being destroyed by it. Many cellular and molecular events govern the cancer's evasion of host immune response. The tumor undergoes continuous remodeling at the genetic, epigenetic and metabolic level to acquire resistance to apoptosis. At the same time, it effectively modifies all the components of the host's immunome so as to escape from its antitumor effects. Moreover, it induces accumulation of suppressive cells like Treg and myeloid derived suppressor cells and factors which also enable it to elude the immune system. Recent research in this area helps in defining the role of newer players like miRNAs and exosomes in immune escape. The immunotherapeutic approaches developed to target the escape phase appear quite promising; however, the quest for a perfect therapeutic agent that can achieve maximum cure with minimal toxicity continues.

Immune response in cervical lymph nodes from patients with primary oral squamous cell carcinoma

BACKGROUND

Deficient immune response in the cervical lymph nodes of patients with head and neck squamous cell carcinoma may contribute to dissemination of metastatic neoplastic cells. This study evaluates the immune response in cervical lymph nodes from patients with primary oral cavity squamous cell carcinoma (OCSCC).

METHODS

The density of immature (CD1a(+)) and mature (CD83(+)) dendritic cells (DCs), cytotoxic T lymphocytes CD8(+) /perforin(+) (CTLs), and Foxp3(+) regulatory T (Tregs) cells in the lymph nodes of patients with OCSCC without cervical lymph node metastases (LN1) (negative) (n = 10) were identified through immunohistochemistry. From patients with cervical lymph node metastases, samples were obtained of lymph nodes both with (LM2) (positive) (n = 10) and without (LN2) (negative) (n = 10) metastases.

RESULTS

The results demonstrated that the number of CD1a(+) and Foxp3(+) cells was significantly higher in the LM2 group than in either the LN1 or the LN2 group. In addition, the number of CD8(+) /perforin(+) and CD83(+) cells was significantly lower in the LM2 group than in the other groups.

CONCLUSION

The results of this study demonstrate a higher density of immature DCs and Tregs cells and a lower density of mature DCs and activated CTLs in metastatic than in non-metastatic lymph nodes. These findings might indicate an immunosuppressive microenvironment, which could be involved in the spread of neoplastic cells to cervical lymph nodes.

Neem leaf glycoprotein overcomes indoleamine 2,3 dioxygenase mediated tolerance in dendritic cells by attenuating hyperactive regulatory T cells in cervical cancer stage IIIB patients

Tolerogenic dendritic cells (DCs) are a subset of DCs characterized by abundant indoleamine 2,3 dioxygenase (IDO) expressions. IDO may be co-operatively induced in DCs by regulatory T (Tregs) cells and various DC maturation agents. Tregs are markedly amplified in the physiological system of cancer patients, inducing over tolerance in DCs that leads to the hyper accumulation of immunosuppressive IDO in tumor microenvironment, thereby, hampering anti-tumor immunity. Consequently, a major focus of current immunotherapeutic strategies in cancer is to minimize IDO, which is possible by reducing Tregs and using various IDO inhibitors. Neem leaf glycoprotein (NLGP), a natural and nontoxic immunomodulator, demonstrated several unique immunoregulatory activities. Noteworthy activities of NLGP are to mature DCs and to inhibit Tregs. As Tregs are inducer of IDO in DCs and hyperactive Tregs is a hallmark of cancer, we anticipated that NLGP might abrogate IDO induction in DCs by inhibiting Tregs. Evidences are presented here that in a co-culture of DCs and Tregs isolated from cervical cancer stage IIIB (CaCx-IIIB) patients, NLGP does inhibit IDO induction in DCs by curtailing the over expression of Cytotoxic T-Lymphocyte Antigen 4 (CTLA4) on Tregs and concomitantly induces optimal DC maturation. In contrast, in the presence of LPS as maturation agent the DCs displays a tolerogenic profile. This finding suggests the reduction of tolerogenecity of DCs in CaCx-IIIB patients by reducing the IDO pool using NLGP. Accordingly, this study sheds more light on the diverse immunomodulatory repertoire of NLGP.

Alterations of dendritic cell subsets and TH1/TH2 cytokines in the peripheral circulation of patients with superficial transitional cell carcinoma of the bladder

BACKGROUND

Dendritic cells (DCs) and cytokines play an important role in the tumor growth and recurrence.

METHODS

Sixty-six patients with superficial transitional cell carcinoma of the bladder (STCCB) and 38 healthy controls were studied to investigate the percentages of DC subsets, monocyte-derived DC (MoDC) function, and alterations of Th1 and Th2 cytokines. MoDCs were generated and three-color flow cytometry was used for determining the phenotype of MoDCs and DC subsets. The ability to stimulate autologous T cells was tested in mixed leukocyte reaction (MLR). The levels of various cytokines were measured using commercially available sandwich enzyme linked immunosorbent assay (ELISA) kit.

RESULTS

The myeloid DC (mDC) counts, MoDC surface molecular expression, and stimulatory capacity to T cells were impaired in STCCB patients than in controls. The percentage of mDC and the expression of CD80, CD83, and CD86 were lower in patients showing recurrence. The serum levels of IL-2 and IFN-γ were found to be significantly lower while IL-4, IL-6, and IL-10 were significantly higher in STCCB patients than in controls. IL-6 was found to be significantly higher in recurrent patients.

CONCLUSION

The impairment of mDC counts and MoDC function with imbalance of Th1/Th2 cytokines was closely associated with proliferation and recurrence of STCCB.

Dendritic cells in the cancer microenvironment

The complexity of the tumor immunoenvironment is underscored by the emergence and discovery of different subsets of immune effectors and regulatory cells. Tumor-induced polarization of immune cell differentiation and function makes this unique environment even more intricate and variable. Dendritic cells (DCs) represent a special group of cells that display different phenotype and activity at the tumor site and exhibit differential pro-tumorigenic and anti-tumorigenic functions. DCs play a key role in inducing and maintaining the antitumor immunity, but in the tumor environment their antigen-presenting function may be lost or inefficient. DCs might be also polarized into immunosuppressive/tolerogenic regulatory DCs, which limit activity of effector T cells and support tumor growth and progression. Although various factors and signaling pathways have been described to be responsible for abnormal functioning of DCs in cancer, there are still no feasible therapeutic modalities available for preventing or reversing DC malfunction in tumor-bearing hosts. Thus, better understanding of DC immunobiology in cancer is pivotal for designing novel or improved therapeutic approaches that will allow proper functioning of DCs in patients with cancer.

Effects of Gekko sulfated polysaccharide-protein complex on the defective biorheological characters of dendritic cells under tumor microenvironment

We previously isolated a sulfated polysaccharide-protein complex from Gekko swinhonis Guenther, a traditional Chinese medicine, and have demonstrated its direct anti-cancer effect on human hepatocellular carcinoma cell line SMMC-7721. Here we investigated the effects of Gekko sulfated polysaccharide-protein complex (GSPP) on the defective biorheological characters of dendritic cells (DCs) under SMMC-7721 microenvironment. Our findings have shown that the biorheological properties of DCs were severely impaired by SMMC-7721 microenvironment, including decreased cell deformability, migration, and electrophoresis mobility, increased osmotic fragilities, and changed organizations of cytoskeletal proteins. We also found decreased secretion of interleukin (IL)-12 and increased secretion of IL-10 in DCs. However, supernatant collected from nonmalignant liver cells had no effect on these parameters. SMMC-7721 cells were treated with GSPP and the supernatant was used to culture DCs. We found that the defective biorheological parameters of DCs, except for osmotic fragility, were partially or completely improved. The secretion of IL-12 did not change as compared with that of DCs in SMMC-7721 microenvironment, but the secretion of IL-10 was resumed to the control level. Our results indicate that GSPP could partially restore the defective biorheological characteristics of DCs via modifying the tumor microenvironment and decreasing the secretion of IL-10 of DCs.

Suppression of natural killer-cell and dendritic-cell apoptotic tumoricidal activity in patients with head and neck cancer

BACKGROUND

Natural killer (NK) cells and dendritic cells (DCs) mediate tumor cell apoptosis using tumor necrosis factor superfamily ligands (TNFSFLs). This cytotoxicity is an important anticancer immune defense mechanism.

METHODS

We examined TNFSFL expression and apoptotic tumoricidal activity (ATA) of purified NK cells and DCs, and peripheral blood mononuclear leukocytes (PBMLs) of healthy individuals and patients with head and neck cancer (HNC) before and after cancer ablation.

RESULTS

PBMLs, NK cells and DCs, but not NK-cell/DC-depleted PBMLs, expressed multiple TNFSFLs and mediated ATA. Both TNFSFL expression and ATA were suppressed in tumor-bearing, and restored in tumor-ablated patients with (HNC) Soluble TNF superfamily receptors (solTNFSFRs) were increasingly bound by PBNLs of tumor-bearing HNC patients. Dissociation of solTNFSFR led to more pronounced increases in TNFSFL expression and ATA of PBMLs of patients with HNC than healthy individuals.

CONCLUSION

NK-cell and DC TNFSFL expression and ATA are suppressed in patients with HNC. This suppression is tumor-dependent and possibly mediated by solTNFSFRs.

Prostate carcinoma cells LNCaP and glucan cooperate in induction of cytokine synthesis by dendritic cells: effect on natural killer cells and CD4+ lymphocytes activation

BACKGROUND

Glucan is an immunomodulating agent used for cancer therapy. We investigated the effects of glucan on immune cell response to prostate carcinoma.

METHODS

Dendritic cells (DC) were co-cultured with prostate carcinoma cells LNCaP and/or glucan, and maturation markers expression, cytokine release, and superoxide anion production were evaluated. Conditioned media from glucan-treated or untreated DC and/or LNCaP cultures were used to stimulate T lymphocytes and natural killer (NK) cells.

RESULTS

LNCaP promoted partial DC maturation and scarce IL-12 secretion. Glucan induced DC maturation but no IL-12 production by DC. However, glucan increased IL-12 release by DC co-cultured with LNCaP. Moreover, LNCaP enhanced IL-1β, IL-23, IL-6, and TNF-α secretion, but decreased superoxide anion production in glucan-stimulated DC. The NADPH oxidase inhibitor diphenyliodonium chloride (DPI) and the superoxide anion scavenger superoxide dismutase (SOD) reproduced this effect, but did not affect IL-12 secretion. Conditioned media of glucan-treated DC/LNCaP co-cultures activated IFN-γ production by NK cells and Th1/Th17 generation by CD4(+) lymphocytes, whereas media from DC/LNCaP co-cultured without glucan produced scarce NK and CD4(+) cells responses. Experiments performed with an IL-12-blocking antibody demonstrated that these effects arise from glucan-dependent regulation of IL-12 production by DC.

CONCLUSIONS

Glucan and LNCaP cooperate in induction of cytokine synthesis by DC. LNCaP enhance IL-1β, IL-23, IL-6, and TNF-α secretion by decreasing glucan-dependent NADPH oxidase activity, whereas glucan increases IL-12 production through NADPH oxidase-unrelated mechanisms. This cooperation is essential to elicit a substantial NK cells and CD4(+) lymphocytes activity, pointing out a potential relevance of glucan in prostate cancer therapy.

Tumor associated regulatory dendritic cells

Immune effector and regulatory cells in the tumor microenvironment are key factors in tumor development and progression as the pathogenesis of cancer vitally depends on the multifaceted interactions between various microenvironmental stimuli provided by tumor-associated immune cells. Immune regulatory cells participate in all stages of cancer development from the induction of genomic instability to the maintenance of intratumoral angiogenesis, proliferation and spreading of malignant cells, and formation of premetastatic niches in distal tissues. Dendritic cells in the tumor microenvironment serve as a double-edged sword and, in addition to initiating potent anti-tumor immune responses, may mediate genomic damage, support neovascularization, block anti-tumor immunity and stimulate cancerous cell growth and spreading. Regulatory dendritic cells in cancer may directly and indirectly maintain antigen-specific and non-specific T cell unresponsiveness by controlling T cell polarization, MDSC and Treg differentiation and activity, and affecting specific microenvironmental conditions in premalignant niches. Understanding the mechanisms involved in regulatory dendritic cell polarization and operation and revealing pharmacological means for harnessing these pathways will provide additional opportunities for modifying the tumor microenvironment and improving the efficacy of different therapeutic approaches to cancer.

Interdisciplinary critique of sipuleucel-T as immunotherapy in castration-resistant prostate cancer

Sipuleucel-T was approved by the US Food and Drug Administration on April 29, 2010, as an immunotherapy for late-stage prostate cancer. To manufacture sipuleucel-T, mononuclear cells harvested from the patient are incubated with a recombinant prostatic acid phosphatase (PAP) antigen and reinfused. The manufacturer proposes that antigen-presenting cells exogenously activated by PAP induce endogenous T-cells to attack PAP-bearing prostate cancer cells. However, the lack of demonstrable tumor responses has prompted calls for scrutiny of the design of the trials in which sipuleucel-T demonstrated a 4-month survival benefit. Previously unpublished data from the sipuleucel-T trials show worse overall survival in older vs younger patients in the placebo groups, which have not been shown previously to be prognostic for survival in castration-resistant prostate cancer patients receiving chemotherapy. Because two-thirds of the cells harvested from placebo patients, but not from the sipuleucel-T arm, were frozen and not reinfused, a detrimental effect of this large repeated cell loss provides a potential alternative explanation for the survival "benefit." Patient safety depends on adequately addressing this alternative explanation for the trial results.

Cancer patients treated with sunitinib or sorafenib have sufficient antibody and cellular immune responses to warrant influenza vaccination

PURPOSE

The tyrosine kinase inhibitors sorafenib and sunitinib have efficacy in several types of cancer. Recent studies indicate that these agents affect the immune system. The way it affects the immune response to influenza vaccination is unknown. The aim of this study was to elucidate the specific immune response to seasonal flu vaccination in cancer patients treated with sunitinib or sorafenib.

PATIENTS AND METHODS

Sunitinib- or sorafenib-treated cancer patients were vaccinated against seasonal influenza with an inactivated vaccine. Healthy controls and patients with metastatic renal cell cancer (mRCC) without systemic treatment (nontreated mRCC controls) were included for comparison. Antibody responses were measured at baseline, day 8, and day 22 by a standard hemagglutination inhibition assay and cellular T-cell responses at baseline and day 8 by proliferation assay and secretion of cytokines.

RESULTS

Forty subjects were enrolled: 16 patients treated with sunitinib, 6 patients with sorafenib, 7 nontreated mRCC controls, and 11 healthy controls. All patients treated with sunitinib and sorafenib developed seroprotection rates comparable with controls. Functional T-cell reactivity was observed in all groups, except for patients treated with sorafenib who showed a decreased proliferation rate and IFN-γ/IL-2 production and increased IL-10 compared with healthy controls.

CONCLUSION

We conclude that influenza vaccination should be recommended to cancer patients treated with sunitinib or sorafenib.

Dendritic cell-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) recognizes a novel ligand, Mac-2-binding protein, characteristically expressed on human colorectal carcinomas

Dendritic cell (DC)-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) is a type II transmembrane C-type lectin expressed on DCs such as myeloid DCs and monocyte-derived DCs (MoDCs). Recently, we have reported that DC-SIGN interacts with carcinoembryonic antigen (CEA) expressed on colorectal carcinoma cells. CEA is one of the most widely used tumor markers for gastrointestinal cancers such as colorectal cancer. On the other hand, other groups have reported that the level of Mac-2-binding protein (Mac-2BP) increases in patients with pancreatic, breast, and lung cancers, virus infections such as human immunodeficiency virus and hepatitis C virus, and autoimmune diseases. Here, we first identified Mac-2BP expressed on several colorectal carcinoma cell lines as a novel DC-SIGN ligand through affinity chromatography and mass spectrometry. Interestingly, we found that DC-SIGN selectively recognizes Mac-2BP derived from some colorectal carcinomas but not from the other ones. Furthermore, we found that the α1-3,4-fucose moieties of Le glycans expressed on DC-SIGN-binding Mac-2BP were important for recognition. DC-SIGN-dependent cellular interactions between immature MoDCs and colorectal carcinoma cells significantly inhibited MoDC functional maturation, suggesting that Mac-2BP may provide a tolerogenic microenvironment for colorectal carcinoma cells through DC-SIGN-dependent recognition. Importantly, Mac-2BP was detected as a predominant DC-SIGN ligand expressed on some primary colorectal cancer tissues from certain parts of patients in comparison with CEA from other parts, suggesting that DC-SIGN-binding Mac-2BP bearing tumor-associated Le glycans may become a novel potential colorectal cancer biomarker for some patients instead of CEA.

Clinical and immunomodulatory effects of celecoxib plus interferon-alpha in metastatic renal cell carcinoma patients with COX-2 tumor immunostaining

INTRODUCTION

Cycloxygenase-2 (COX-2) is an enzyme involved in prostaglandin E2 (PGE(2)) synthesis associated with higher renal cell carcinoma stage. COX-2 inhibition enhances interferon (IFN-α) anti-tumor immune effects in pre-clinical models. A phase II trial of celecoxib and IFN-α in a targeted population of metastatic renal cell carcinoma patients with maximal COX-2 expression was conducted.

METHODS

Cytokine-naive metastatic renal cell carcinoma patients with tumors expressing ≥10% maximal COX-2 staining by immunohistochemistry received IFN-α 5 million units daily and celecoxib 400 mg orally twice daily in an open-label, single-arm phase II trial.

RESULTS

There were 3 partial responses among 17 patients (objective response rate 18%; 95% confidence interval, 4-43%). Time to progression was 5.6 months. Increased tumor staining 3+ for COX-2 was associated with increased baseline peripheral blood PGE(2) levels, and these patients demonstrated less PGE(2) decrease with therapy. Patients with more 3+ COX-2 staining had significantly more CD3(+) (p = 0.004) and CD4(+) (p = 0.002) IFN-γ T cells at baseline and a significantly greater decrease in these cells with therapy.

DISCUSSION

Celecoxib plus IFN-α in renal cell carcinoma (RCC) patients with maximally staining COX-2 tumors does not significantly enhance overall response rates over IFN monotherapy.

CONCLUSION

COX-2-expressing RCC demonstrates inherent immunosuppression. COX-2 inhibition with IFN results in minimal immunomodulation and no augmented clinical activity in RCC.

Leukemic cell products down-regulate human dendritic cell differentiation

The microenvironment produced by solid tumors is inhibitory to the immune system, inducing dendritic cell (DC) alterations, but there is a paucity of information regarding haematological malignances. The aim of this study was to investigate DC differentiation under the influence of leukemic cell products. Monocytes from healthy volunteers were cultured in the presence of IL-4 and GM-CSF for the generation of immature DCs. Supernatants from leukemic cultures were added to monocyte cultures during differentiation. The lineages used were K562, a chronic myeloid leukemia, HL-60, a promyelocytic leukemia and DAUDI, originated from Burkitt lymphoma. It was observed that the expression of CD14 remained high and the CD1a was low in the presence of tumor supernatants, while non-malignant supernatants did not affect these parameters. Furthermore, IL-1beta and TNF-alpha production by monocytes during differentiation was increased by the presence of tumor supernatants. The modifications on CD14 and CD1a expressions could be mimicked by the addition of exogenous IL-1beta and partially inhibited by the neutralization of IL-1beta. These results suggest that soluble products from leukemic cells interfere with DC differentiation and, in the present work, this effect could be mediated by monocyte-derived IL-1beta in response to tumor supernatants.

Update on vaccine development for renal cell cancer

Renal cell carcinoma (RCC) remains a significant health concern that frequently presents as metastatic disease at the time of initial diagnosis. Current first-line therapeutics for the advanced-stage RCC include antiangiogenic drugs that have yielded high rates of objective clinical response; however, these tend to be transient in nature, with many patients becoming refractory to chronic treatment with these agents. Adjuvant immunotherapies remain viable candidates to sustain disease-free and overall patient survival. In particular, vaccines designed to optimize the activation, maintenance, and recruitment of specific immunity within or into the tumor site continue to evolve. Based on the integration of increasingly refined immunomonitoring systems in both translational models and clinical trials, allowing for the improved understanding of treatment mechanism(s) of action, further refined (combinational) vaccine protocols are currently being developed and evaluated. This review provides a brief history of RCC vaccine development, discusses the successes and limitations in such approaches, and provides a rationale for developing combinational vaccine approaches that may provide improved clinical benefits to patients with RCC.

Histiocytosis disorders in Northeast Egypt: epidemiology and survival studies (a 5-year study)

Histiocytosis disorders include a wide group of disorders characterized by monocytes, macrophages and dendritic cell infiltration of different tissues. There are few clinico-epidemiologic studies of such disease. Our study was designed to look at the clinico-epidemiological features and outcome of patients with histiocytosis disorders in Northeast Egypt. Twenty-seven cases with histiocytosis disorders accrued over a 5-year period were analyzed and classified as having unifocal, multifocal, or multisystem disease. They were 14 males and 13 females. Twenty-two patients representing 81.5% of cases were more than two years of age while 5 patients (18.5%) were less than 2 years. Lymphadenopathy was the commonest presentation (55.55%) followed by bone lesions (44.44%). Involvement was unifocal in 12, multifocal in 10, and multisystem in 5 cases. The histological features were relatively uniform regardless of the clinical severity, and consisted of Langerhans cells, eosinophils, histiocytes, plasma cells, giant cells and fibrosis. The treatment consisted of a combination of surgery, chemotherapy, and/or radiotherapy. Lymphadenopathy was the most common clinical presentation in our locality. Response to treatment was poor in patients with multisystem disease. Patients with age less than 2 years were more likely to have increased risk of morbidity and mortality, due to widespread disease.

The role of immunity in elderly cancer

The increased incidence of malignancies in elderly patients living in industrialized countries has led to both identify the causes that alter the normal homeostatic balance in elderly and designate the specific treatments. The progressive decline of the immune system (immunosenescence) involving cellular and molecular alterations impact both innate and adaptive immunity. The immunosenescence leads to increased incidence of infectious diseases morbidity and mortality as well as heightened rates of other immune disorders such as autoimmunity, cancer, and inflammatory conditions. Here, we summarize the knowledge on the major changes in the immune system associated with aging in primary lymphoid organs as well as a description of molecular mechanisms, and the impact on cancer development.