Immunity to melanoma: unraveling the relation of tumor immunity and autoimmunity

A Yeast Cell Wall Derived Hybrid Hydrogel with Photothermal and Immune Combined Modality Therapy for Enhanced Anti-Melanoma Efficacy

Introduction

The effect of traditional treatment for melanoma is quite limited, especially for its recurrence. As the major components of yeast cell wall, chitin and β-glucan exhibit good immune activation effect and are promising candidates for adjuvant. Therefore, melanoma cell membrane (CM) and indocyanine green (ICG) was loaded in a chitin and β-glucan hybrid hydrogel to achieve an enhanced anti-melanoma therapy.

Methods

The novel hybrid hydrogel was prepared, and its physicochemical properties were examined. Its effect towards melanoma prevention and treatment was evaluated via a melanoma-bearing mice model.

Results

The CM-ICG-hybrid hydrogel was successfully prepared with excellent injectability, self-healing, drug loading, rheological, in vitro and in vivo photothermal stability, and retention properties. It also exhibited good cellular and in vivo safety profiles. In the primary melanoma mice model, it quickly ablated the in-situ melanoma, effectively inhibited the tumor growth, increased the survival rate of melanoma-bearing mice, and increased the level of IFN-γ and TNF-α. In the distal secondary melanoma model, it efficiently prevented the reoccurrence of melanoma and activated the memory T cells. In both models, a synergistic effect of photothermal therapy and immune therapy was found. The hydrogel effectively recruited CD3+ CD4+ T cells and CD3+ CD8+ T cells, inhibited the proliferation of melanoma cells, and induced the apoptosis of melanoma cells.

Conclusion

The hybrid hydrogel was successfully prepared, and it showed excellent efficacy towards melanoma prevention and treatment due to its efficient tumor ablation and immune activation capability.

Biology of cancer; from cellular and molecular mechanisms to developmental processes and adaptation

Cancer research has been largely focused on the cellular and molecular levels of investigation. Recent data show that not only the cell but also the extracellular matrix plays a major role in the progression of malignancy. In this way, the cells and the extracellular matrix create a specific local microenvironment that supports malignant development. At the same time, cancer implies a systemic evolution which is closely related to developmental processes and adaptation. Consequently, there is currently a real gap between the local investigation of cancer at the microenvironmental level, and the pathophysiological approach to cancer as a systemic disease. In fact, the cells and the matrix are not only complementary structures but also interdependent components that act synergistically. Such relationships lead to cell-matrix integration, a supracellular form of biological organization that supports tissue development. The emergence of this supracellular level of organization, as a structure, leads to the emergence of the supracellular control of proliferation, as a supracellular function. In humans, proliferation is generally involved in developmental processes and adaptation. These processes suppose a specific configuration at the systemic level, which generates high-order guidance for local supracellular control of proliferation. In conclusion, the supracellular control of proliferation act as an interface between the downstream level of cell division and differentiation, and upstream level of developmental processes and adaptation. Understanding these processes and their disorders is useful not only to complete the big picture of malignancy as a systemic disease, but also to open new treatment perspectives in the form of etiopathogenic (supracellular or informational) therapies.

Expression of Autoimmunity-Related Genes in Melanoma

Simple Summary

The present study selected four genes strongly related to autoimmunity. Their expression was found to be significantly altered in melanoma patients according to a multi-validation procedure carried out on 1948 patients. Such genes may represent suitable molecular targets to further investigate the role autoimmunity may play in melanoma setup and development. Our data suggest that autoimmunity may play a beneficial role in melanoma set up, at least to some extent.

Abstract

(1) Background. Immune response dysregulation plays a key role in melanoma, as suggested by the substantial prognosis improvement observed under immune-modulation therapy. Similarly, the role of autoimmunity is under large investigation in melanoma and other cancers. (2) Methods. Expression of 98 autoimmunity-related genes was investigated in 1948 individuals (1024 melanoma and 924 healthy controls). Data were derived from four independent databases, namely, GEO in the selection phase, and Ist Online, GEPIA2 and GENT2, in three sequential validation-steps. ROC analyses were performed to measure the ability to discriminate melanoma from controls. Principal Component Analysis (PCA) was used to combine expression data; survival analysis was carried out on the GEPIA2 platform. (3) Results. Expression levels of NOD2, BAX, IL-18 and ADRB2 were found to be significantly different in melanoma vs. controls and discriminate melanoma from controls in an extremely effective way, either as single molecules (AUC > 0.93 in all cases) or as a profile, according to the PCA analysis. Patients showing high-expression of NOD2 and of IL-18 also show a significant survival improvement as compared to low-expression patients. (4) Conclusions. Four genes strongly related to autoimmunity show a significant altered expression in melanoma samples, highlighting the role they may play in melanoma.

Histological regression in melanoma: impact on sentinel lymph node status and survival

Regression in melanoma is an immunological phenomenon that results in partial or complete replacement of the tumor with variably vascular fibrous tissue, often accompanied by pigment-laden macrophages and chronic inflammation. In some cases, tumor-infiltrating lymphocytes (TILs) may represent the earliest phase of this process. The prognostic significance of regression has long been a matter of debate, with inconsistent findings reported in the literature to date. This study sought to determine whether regression in primary cutaneous melanomas predicted sentinel lymph node (SLN) status and survival outcomes in a large cohort of patients managed at a single centre. Clinical and pathological parameters for 8,693 consecutive cases were retrieved. Associations between regression and SLN status, overall survival (OS), melanoma-specific survival (MSS) and recurrence-free survival (RFS) were investigated using logistic and Cox regression. Histological evidence of regression was present in 1958 cases (22.5%). Regression was significantly associated with lower Breslow thickness, lower mitotic rate, and absence of ulceration (p < 0.0001). Multivariable analysis showed that regression in combination with TILs independently predicted a negative SLN biopsy (OR 0.33; 95% C.I. 0.20-0.52; p < 0.0001). Patients whose tumors showed both regression and TILs had the highest 10-year OS (65%, 95% C.I. 59-71%), MSS (85%, 95% C.I. 81-89%), and RFS (60%, 95% C.I. 54-66%). On multivariable analyses, the concurrent presence of regression and TILs independently predicted the lowest risk of death from melanoma (HR 0.69; 95% C.I. 0.51-0.94; p = 0.0003) as well as the lowest rate of disease recurrence (HR 0.71; 95% C.I. 0.58-0.85; p < 0.0001). However, in contrast, in the subgroup analysis of Stage III patients, the presence of regression predicted the lowest OS and RFS, with MSS showing a similar trend. Overall, these findings indicate a prognostically favorable role of regression in primary cutaneous melanoma. However, in Stage III melanoma patients, regression may be a marker of more aggressive disease.

Immunobiology of Melanoma

Despite the ability of immune-based interventions to dramatically increase the survival of patients with melanoma, a significant subset fail to benefit from this treatment, underscoring the need for accurate means to identify the patient population likely to respond to immunotherapy. Understanding how melanoma evades natural or manipulated immune responses could provide the information needed to identify such resistant individuals. Efforts to address this challenge are hampered by the vast immune diversity characterizing tumor microenvironments that remain largely understudied. It is thus important to more clearly elucidate the complex interactions that take place between the tumor microenvironment and host immune system.

Sex differences in the association between tumor growth and T cell response in a melanoma mouse model

Epidemiological evidence suggests that females have an advantage over males in cases of melanoma incidence, progression, and survival. However, the biological mechanisms underlying these sex differences remain unclear. With the knowledge that females generally have a more robust immune system than males, we investigated sex differences in melanoma progression in a B16-F10/BL6 syngeneic mouse model. We observed significantly less tumor volume and growth rate over 14 days in female mice compared to male mice. Furthermore, higher populations of CD4⁺ and CD8⁺ T cells, which indicate adaptive immune responses, were found in the circulating blood and tumors of females and corresponded with less tumor growth, and vice versa in males. Our results highlight a mouse model that represents melanoma progression in the human population and displays a higher immune response to melanoma in females compared to males. These findings suggest that the immune system may be one of the mechanisms responsible for sex differences in melanoma.

Spontaneous regression of pancreatic cancer with liver metastases

Spontaneous cancer regression is a rare event, scarcely reported among gastrointestinal malignancies. Pancreatic adenocarcinoma regression has been documented in five previous cases, none of which included liver metastases, and the mechanism by which this occurs is not known. A 56-year-old woman with history of discoid lupus, homocysteinemia and peripheral vascular disease was diagnosed with stage IV pancreatic ductal adenocarcinoma (PDA) metastatic to the liver. She received palliative chemotherapy with 5-fluorouracil, leucovorin, irinotecan and oxaliplatin (FOLFIRINOX) for 6 months, complicated by mucositis, diarrhoea, vomiting and two Clostridium difficile colitis episodes. Cancer initially responded to chemotherapy. However, due to substantial toxicities, she decided to discontinue cytotoxic chemotherapy and focus on palliation alone. Thereafter, CT and carbohydrate antigen (CA) 19-9 showed further response and ultimately complete cancer regression that has persisted for 33 months after cessation of chemotherapy. This is the first report in the English literature showing spontaneous regression of a PDA with liver metastases. Two possible mechanisms are proposed: antitumoral autoimmunity and tumour hypoxia related to vascular disease.

The circadian clock regulates cisplatin-induced toxicity and tumor regression in melanoma mouse and human models

Cisplatin is one of the most commonly used chemotherapeutic drugs; however, toxicity and tumor resistance limit its use. Studies using murine models and human subjects have shown that the time of day of cisplatin treatment influences renal and blood toxicities. We hypothesized that the mechanisms responsible for these outcomes are driven by the circadian clock. We conducted experiments using wild-type and circadian disrupted Per1/2^-/- mice treated with cisplatin at selected morning (AM) and evening (PM) times. Wild-type mice treated in the evening showed an enhanced rate of removal of cisplatin-DNA adducts and less toxicity than the morning-treated mice. This temporal variation in toxicity was lost in the Per1/2^-/- clock-disrupted mice, suggesting that the time-of-day effect is linked to the circadian clock. Observations in blood cells from humans subjected to simulated day and night shift schedules corroborated this view. Per1/2^-/- mice also exhibited a more robust immune response and slower tumor growth rate, indicating that the circadian clock also influences the immune response to melanoma tumors. Our findings indicate that cisplatin chronopharmacology involves the circadian clock control of DNA repair as well as immune responses, and thus affects both cisplatin toxicity and tumor growth. This has important implications for chronochemotherapy in cancer patients, and also suggests that influencing the circadian clock (e.g., through bright light treatment) may be explored as a tool to improve patient outcomes.

Recent Successes and Future Directions in Immunotherapy of Cutaneous Melanoma

The global health burden associated with melanoma continues to increase while treatment options for metastatic melanoma are limited. Nevertheless, in the past decade, the field of cancer immunotherapy has witnessed remarkable advances for the treatment of a number of malignancies including metastatic melanoma. Although the earliest observations of an immunological antitumor response were made nearly a century ago, it was only in the past 30 years, that immunotherapy emerged as a viable therapeutic option, in particular for cutaneous melanoma. As such, melanoma remains the focus of various preclinical and clinical studies to understand the immunobiology of cancer and to test various tumor immunotherapies. Here, we review key recent developments in the field of immune-mediated therapy of melanoma. Our primary focus is on therapies that have received regulatory approval. Thus, a brief overview of the pathophysiology of melanoma is provided. The purported functions of various tumor-infiltrating immune cell subsets are described, in particular the recently described roles of intratumoral dendritic cells. The section on immunotherapies focuses on strategies that have proved to be the most clinically successful such as immune checkpoint blockade. Prospects for novel therapeutics and the potential for combinatorial approaches are delineated. Finally, we briefly discuss nanotechnology-based platforms which can in theory, activate multiple arms of immune system to fight cancer. The promising advances in the field of immunotherapy signal the dawn of a new era in cancer treatment and warrant further investigation to understand the opportunities and barriers for future progress.

miRNAs, Melanoma and Microenvironment: An Intricate Network

miRNAs are central players in cancer biology and they play a pivotal role in mediating the network communication between tumor cells and their microenvironment. In melanoma, miRNAs can impair or facilitate a wide array of processes, and here we will focus on: the epithelial to mesenchymal transition (EMT), the immune milieu, and metabolism. Multiple miRNAs can affect the EMT process, even at a distance, for example through exosome-mediated mechanisms. miRNAs also strongly act on some components of the immune system, regulating the activity of key elements such as antigen presenting cells, and can facilitate an immune evasive/suppressive phenotype. miRNAs are also involved in the regulation of metabolic processes, specifically in response to hypoxic stimuli where they can mediate the metabolic switch from an oxidative to a glycolytic metabolism. Overall, this review discusses and summarizes recent findings on miRNA regulation in the melanoma tumor microenvironment, analyzing their potential diagnostic and therapeutic applications.

Uncarboxylated Osteocalcin Induces Antitumor Immunity against Mouse Melanoma Cell Growth

Because of the poor response to chemotherapy and radiation therapy, new treatment approaches by immune-based therapy involving activated T cells are required for melanoma. We previously reported that the uncarboxylated form of osteocalcin (GluOC), derived from osteoblasts, potentially suppresses human prostate cancer cell proliferation by direct suppression of cell growth. However, the mechanisms in vivo have not been elucidated. In this study, we found that GluOC suppressed tumor growth of B16 mouse melanoma transplants in C57Bl/6N wild-type mice. Our data demonstrated that GluOC suppressed cell growth by downregulating phosphorylation levels of receptor tyrosine kinases and inducing apoptosis in vitro. Additionally, stimulation of primary mouse splenocytes with concanavalin A, a polyclonal T-cell mitogen, in the presence of GluOC increased T cell proliferation and their interferon-γ production. Taken together, we demonstrate that GluOC exerts multiple antitumor effects not only in vitro, but also in vivo through cellular immunostimulatory effects against B16 mouse melanoma cells.

Selenium-Binding Protein 1 (SBP1) autoantibodies in ovarian disorders and ovarian cancer

Infertility is a risk factor for ovarian cancer (OvCa). The goal was to determine if antibodies to selenium-binding protein 1 (SBP1), an autoantibody we identified in patients with premature ovarian failure (POF), occurs in both infertility and OvCa patients, and thus could be associated with preneoplasia. Anti-SBP1 was measured by immunoassay against recombinant SBP1, in sera from OvCa (n = 41), infertility (n = 92) and control (n = 87) patients. Infertility causes were POF, unexplained, irregular ovulation or endometriosis. The percent of anti-SBP1-positive sera was higher in POF (P = 0.02), irregular ovulation (P = 0.001), unexplained causes (P = 0.02), late (III-IV)-stage OvCa (P = 0.02) but was not significant in endometriosis, benign ovarian tumors/cysts, early stage (I-II) OvCa or uterine cancer compared to healthy controls. Anti-SBP1 was significantly higher in women with serous (P = 0.04) but not non-serous (P = 0.33) OvCa compared to controls. Also, we determined if anti-SBP1 was associated with CA125 or anti-TP53, markers often studied in OvCa. Anti-TP53 and CA125 were measured by established immunoassays. The ability of anti-SBP1 alone to discriminate infertility or OvCa from controls or when combined with anti-TP53 and CA125, to identify OvCa was evaluated by comparing the area under the curve (AUC) in ROC analysis. Anti-SBP1 alone discriminated infertility (AUC = 0.7; P = 0.001) or OvCa (AUC = 0.67; P = 0.03) from controls. The sensitivity and specificity of OvCa identification was increased by combining CA125, anti-TP53 and anti-SBP1 (AUC = 0.96). Therefore, anti-SBP1 occurs in infertile women with POF, ovulatory disturbances or unexplained infertility and in serous OvCa. This suggests an autoimmune process is associated with the development of serous OvCa.

High Interleukin 27 Production is Associated with Early Clinical Stage and Localized Disease in Patients with Melanoma

BACKGROUND

The immune response in patients with melanoma is an important focus of research due to the tumor's resistance and immunotherapy possibilities. IL-27 is one of the cytokines with antitumor properties. The role of IL-27 in the pathogenesis of melanoma is still unclear. The aim of this study was to examine the association between serum IL-27 levels and the clinical parameters of melanoma patients.

METHODS

The IL-27 concentration was determined by com mercial ELISA in serum samples from melanoma patients (n=72) and healthy control subjects (n=44). Patients were classified according to AJCC clinical stage, TNM stage, the length of progression-free interval (PFI) and the extent of the disease (localized or widespread).

RESULTS

Average IL-27 values were increased in patients with early stages of melanoma compared to patients with terminal stages and control values. The highest IL-27 concentration was found in stage IIa. Patients in stages III and IV had significantly lower values of IL-27 compared to control. Patients with localized melanoma and shorter PFI had insignificantly increased IL-27 levels compared to patients with widespread disease and longer PFI. Patients with metastatic disease and stage TNM4 had significantly lower average IL-27 values compared to control. Patients with high production of IL-27 (>1000 pg/mL) were most numerous in IIa AJCC stage, with initial tumor size TNM2 and in the group of patients with localized disease.

CONCLUSIONS

High levels of IL-27 in patients with melanoma are associated with the initial stages and lo calized disease.

Early Tumor-Infiltrating Dendritic Cells Change their Characteristics Drastically in Association with Murine Melanoma Progression

Dendritic cells (DCs) have a critical effect on the outcome of adaptive immune responses against growing tumors. Tumor-infiltrating dendritic cells (TIDCs) play diverse roles in the regulation of tumor regression or growth, but the characteristics that distinguish those effects are obscure. In this study, we investigated the frequency, phenotype, and function of TIDCs over time from early stages of melanoma growth in mice. Flow cytometric analysis revealed that the tumors were infiltrated by a significant population of CD11c(+) major histocompatibility complex II(+) DCs, especially at an early stage of tumor growth. The allogeneic stimulatory capacity of TIDCs increased with tumor growth, whereas this capacity of DCs in lymph nodes decreased. TIDCs harvested at an early stage of melanoma (early TIDCs) accelerated tumor growth, but those harvested at a late stage (late TIDCs) delayed tumor progression when they were coinjected with melanoma cells. Furthermore, coinjection of early TIDCs failed to induce full immunocompetent maturation of CD8(+) T cells, with much lower expression of IFN-γ, granzyme B, and perforin within the tumor microenvironment. In conclusion, TIDCs change their characteristics from an immunoinhibitory to an immunostimulatory phenotype over time in association with tumor progression.

mRNA-based dendritic cell immunization improves survival in ret transgenic mouse melanoma model

Malignant melanoma is characterized by a rapid progression, metastasis to distant organs and resistance to chemo and radiotherapy. Although melanoma is capable of eliciting an immune response, the disease progresses and the overall results of immunotherapeutic clinical studies are not satisfactory. Recently, we have developed a novel genetic platform for improving an induction of peptide-specific CD8(+) T cells by dendritic cell (DC) based on membrane-anchored β2-microglobulin (β2m) linked to a selected antigenic peptide at the N-terminus and to the cytosolic domain of TLR4 at the C-terminus. In vitro transcribed mRNA transfection of antigen-presenting cells (APCs) resulted in an efficient coupling of peptide presentation and cell activation. In this research, we utilize the chimeric platform to induce an immune response in ret transgenic mice that spontaneously develop malignant skin melanoma and to examine its effect on the overall survival of tumor-bearing mice. Following immunization with chimeric construct system, we observe a significantly prolonged survival of tumor-bearing mice as compared to the control group. Moreover, we see elevations in the frequency of CD62L(hi)CD44(hi) central and CD62L(lo)CD44(hi) effector memory CD8(+) T-cell subsets. Importantly, we do not observe any changes in frequencies of regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) in the vaccinated groups. Our data suggest that this novel vaccination approach could be efficiently applied for the immunotherapy of malignant melanoma.

Id1 suppresses anti-tumour immune responses and promotes tumour progression by impairing myeloid cell maturation

A central mechanism of tumour progression and metastasis involves the generation of an immunosuppressive ‘macroenvironment' mediated in part through tumour-secreted factors. Here we demonstrate that upregulation of the Inhibitor of Differentiation 1 (Id1), in response to tumour-derived factors, such as TGFβ, is responsible for the switch from dendritic cell (DC) differentiation to myeloid-derived suppressor cell expansion during tumour progression. Genetic inactivation of Id1 largely corrects the myeloid imbalance, whereas Id1 overexpression in the absence of tumour-derived factors re-creates it. Id1 overexpression leads to systemic immunosuppression by downregulation of key molecules involved in DC differentiation and suppression of CD8 T-cell proliferation, thus promoting primary tumour growth and metastatic progression. Furthermore, advanced melanoma patients have increased plasma TGFβ levels and express higher levels of ID1 in myeloid peripheral blood cells. This study reveals a critical role for Id1 in suppressing the anti-tumour immune response during tumour progression and metastasis.

Tumour progression is promoted by the generation of an immunosuppressive macroenvironment. Here, the authors demonstrate that the Inhibitor of Differentiation 1 promotes the switch from dendritic cell differentiation towards myeloid-derived suppressor cell expansion during tumour progression.

Genetic engineering of hematopoietic stem cells to generate invariant natural killer T cells

Invariant natural killer T (iNKT) cells comprise a small population of αβ T lymphocytes. They bridge the innate and adaptive immune systems and mediate strong and rapid responses to many diseases, including cancer, infections, allergies, and autoimmunity. However, the study of iNKT cell biology and the therapeutic applications of these cells are greatly limited by their small numbers in vivo (∼0.01-1% in mouse and human blood). Here, we report a new method to generate large numbers of iNKT cells in mice through T-cell receptor (TCR) gene engineering of hematopoietic stem cells (HSCs). We showed that iNKT TCR-engineered HSCs could generate a clonal population of iNKT cells. These HSC-engineered iNKT cells displayed the typical iNKT cell phenotype and functionality. They followed a two-stage developmental path, first in thymus and then in the periphery, resembling that of endogenous iNKT cells. When tested in a mouse melanoma lung metastasis model, the HSC-engineered iNKT cells effectively protected mice from tumor metastasis. This method provides a powerful and high-throughput tool to investigate the in vivo development and functionality of clonal iNKT cells in mice. More importantly, this method takes advantage of the self-renewal and longevity of HSCs to generate a long-term supply of engineered iNKT cells, thus opening up a new avenue for iNKT cell-based immunotherapy.

Autoimmunity and tumor immunology: two facets of a probabilistic immune system

Background

The immune system of vertebrates has evolved the ability to mount highly elaborate responses to a broad range of pathogen-driven threats. Accordingly, it is quite a challenge to understand how a primitive adaptive immune system that probably lacked much of its present complexity could provide its bearers with significant evolutionary advantage, and therefore, continue to be selected for.

Results

We have developed a very simple model of the immune system that captures the probabilistic communication between its innate and adaptive components. Probabilistic communication arises specifically from the fact that antigen presenting cells collect and present a range of antigens from which the adaptive immune system must (probabilistically) identify its target. Our results show that although some degree of self-reactivity in the immune repertoire is unavoidable, the system is generally able to correctly target pathogens rather than self-antigens. Particular circumstances that impair correct targeting and that may lead to infection-induced autoimmunity can be predicted within this framework. Notably, the probabilistic immune system exhibits the remarkable ability to detect sudden increases in the abundance of rare self-antigens, which represents a first step towards developing anti-tumoral responses.

Conclusion

A simple probabilistic model of the communication between the innate and adaptive immune system provides a robust immune response, including targeting tumors, but at the price of being at risk of developing autoimmunity.

Ret transgenic mouse model of spontaneous skin melanoma: focus on regulatory T cells

Ret transgenic mouse model of skin malignant melanoma is characterized by the overexpression of the human ret transgene in melanin-containing cells. Transgenic mice spontaneously develop skin tumors with metastases in lymph nodes, lungs, liver, brain, and the bone marrow. Tumor lesions show typical melanoma morphology and express melanoma-associated antigens. Although transgenic mice demonstrate an accumulation of melanoma antigen-specific memory and effector T cells, their anti-tumor effects could be blocked by highly immunosuppressive leukocytes enriched in the tumor microenvironment and in the periphery. Here, we discuss the role of one of the most potent immunosuppressive subset, regulatory T cells, in the melanoma progression in this model.

Anti-HE4 antibodies in infertile women and women with ovarian cancer

OBJECTIVES

To develop an assay for anti-HE4 antibodies and assess such antibodies in sera from women with increased epidemiologic risk for ovarian cancer (infertility) and patients with ovarian cancer in comparison to controls.

METHODS

An ELISA was developed to measure antibodies to recombinant full length HE4 and cut-off values were determined for different levels of specificity (up to 99%).

RESULTS

Infertile women more frequently had anti-HE4 antibodies than controls (23% at 98% specificity, p < 0.001) with antibodies most frequent in women with POF (31%) and ovulatory dysfunction (47%). There was also an increased frequency of anti-HE4 antibodies in patients with ovarian cancer (14% at 97% specificity, p < 0.01), but more women with certain types of infertility have anti-HE4 antibodies than women with ovarian cancer. Most patients with ovarian cancer have circulating HE4 antigen, which may interfere with detection of antibodies, while the level of HE4 antigen in sera from infertile women was not higher than in normal controls. There was a statistically significant correlation between antibodies to HE4 and antibodies to mesothelin in the same patients.

CONCLUSIONS

Women with certain types of infertility, which have increased risk to develop ovarian cancer, and women with ovarian cancer more frequently than controls have antibodies to HE4, a biomarker for ovarian cancer. The antibodies may reflect a tumor-promoting Th2 type of inflammation.

Tumor microenvironment and myeloid-derived suppressor cells

Tumor progression has been demonstrated to be supported by chronic inflammatory conditions developed in the tumor microenvironment and characterized by the long-term secretion of various inflammatory soluble factors (including cytokines, chemokines, growth factors, reactive oxygen and nitrogen species, prostaglandins etc.) and strong leukocyte infiltration. Among leukocytes infiltrating tumors, myeloid-derived suppressor cells (MDSCs) represent one of the most important players mediating immunosuppression. These cells may not only strongly inhibit an anti-tumor immune reactions mediated by T cells but also directly stimulate tumorigenesis, tumor growth and metastasis by enhancing neoangiogenesis and creating a suitable environment for the metastatic formation. This review provides an overview of interactions between MDSCs and tumor cells leading to MDSC generation, activation and migration to the tumor site, where they can strongly enhance tumor progression. Better understanding of the MDSC-tumor interplay is critical for the development of new strategies of tumor immunotherapy.

Immunological basis of melanoma-associated vitiligo-like depigmentation

Vitiligo is a skin condition characterized by white, hypopigmented macules. Melanocyte loss is a feature of the disease, and it has been hypothesized that an autoimmune mechanism could be responsible for the depigmentation. Melanoma is a malignancy that develops in melanocytes; if not detected and treated early, it is often deadly. Leukoderma, a condition characterized by depigmentation of the skin, is sometimes associated with malignant melanoma. An immune response against melanocyte antigens leading to destruction of either melanoma cells or melanocytes has been observed in both vitiligo and melanoma. Studies in animal models and humans have shown that humoral and cell-mediated immune responses are involved in modulating cytotoxic activity against tumor cells and normal melanocytes. The study of factors associated with anti-tumor immunopathogenic mechanisms -autoimmunity for example- may provide us with tools for the diagnosis and treatment of diseases such as vitiligo and malignant melanoma.

Cellular and cytokine-dependent immunosuppressive mechanisms of grm1-transgenic murine melanoma

Grm1-transgenic mice spontaneously develop cutaneous melanoma. This model allowed us to scrutinize the generic immune responses over the course of melanoma development. To this end, lymphocytes obtained from spleens, unrelated lymph nodes and tumor-draining lymph nodes of mice with no evidence of disease, and low or high tumor burden were analyzed ex vivo and in vitro. Thereby, we could demonstrate an increase in the number of activated CD4⁺ and CD8⁺ lymphocytes in the respective organs with increasing tumor burden. However, mainly CD4⁺ T cells, which could constitute both T helper as well as immunosuppressive regulatory T cells, but not CD8⁺ T cells, expressed activation markers upon in vitro stimulation when obtained from tumor-bearing mice. Interestingly, these cells from tumor-burdened animals were also functionally hampered in their proliferative response even when subjected to strong in vitro stimulation. Further analyses revealed that the increased frequency of regulatory T cells in tumor-bearing mice is an early event present in all lymphoid organs. Additionally, expression of the immunosuppressive cytokines TGF-β1 and IL-10 became more evident with increased tumor burden. Notably, TGF-β1 is strongly expressed in both the tumor and the tumor-draining lymph node, whereas IL-10 expression is more pronounced in the lymph node, suggesting a more complex regulation of IL-10. Thus, similar to the situation in melanoma patients, both cytokines as well as cellular immune escape mechanisms seem to contribute to the observed immunosuppressed state of tumor-bearing grm1-transgenic mice, suggesting that this model is suitable for preclinical testing of immunomodulatory therapeutics.

T-Cell Mediated Immune Responses Induced in ret Transgenic Mouse Model of Malignant Melanoma

Poor response of human malignant melanoma to currently available treatments requires a development of innovative therapeutic strategies. Their evaluation should be based on animal models that resemble human melanoma with respect to genetics, histopathology and clinical features. Here we used a transgenic mouse model of spontaneous skin melanoma, in which the ret transgene is expressed in melanocytes under the control of metallothionein-I promoter. After a short latency, around 25% mice develop macroscopic skin melanoma metastasizing to lymph nodes, bone marrow, lungs and brain, whereas other transgenic mice showed only metastatic lesions without visible skin tumors. We found that tumor lesions expressed melanoma associated antigens (MAA) tyrosinase, tyrosinase related protein (TRP)-1, TRP-2 and gp100, which could be applied as targets for the immunotherapy. Upon peptide vaccination, ret transgenic mice without macroscopic melanomas were able to generate T cell responses not only against a strong model antigen ovalbumin but also against typical MAA TRP-2. Although mice bearing macroscopic primary tumors could also display an antigen-specific T cell reactivity, it was significantly down-regulated as compared to tumor-free transgenic mice or non-transgenic littermates. We suggest that ret transgenic mice could be used as a pre-clinical model for the evaluation of novel strategies of melanoma immunotherapy.

Melanoma-induced immunosuppression and its neutralization

Malignant melanoma is characterized by a rapid progression, metastasis to distant organs, and resistance to chemo- and radiotherapy. Well-defined immunogenic capacities of melanoma cells should allow a successful application of different immunotherapeutic strategies. However, the overall results of immunotherapeutic clinical studies are not satisfactory. These paradoxical observations are supposed to be due to the profound immunosuppression mediated by different mechanisms dealing with alterations in tumor and surrounding stroma cells. Melanoma microenvironment has been characterized by a remarkable accumulation of highly immunosuppressive regulatory leucocytes, in particular, myeloid-derived suppressor cells (MDSCs). Their migration, retention and high activity in the tumor lesions have been demonstrated to be induced by chronic inflammatory conditions developing in the tumor microenvironment and characterized by the long-term secretion of various inflammatory mediators (cytokines, chemokines, growth factors, reactive oxygen and nitrogen species, prostaglandins etc.) leading to further cancer progression. Here, we discuss the role of chronic inflammation in the recruitment and activation of MDSCs in melanoma lesions as well as therapeutic approaches of MDSC targeting to overcome tumor immunosuppressive microenvironment induced by chronic inflammation and enhance the efficiency of melanoma immunotherapies.

Clinical utility of serum autoantibodies detected by protein microarray in melanoma

Better prognostic and predictive markers in melanoma are needed to select patients for therapy. We utilized a dual-lectin affinity chromatography and a natural protein microarray-based analysis to select a subproteome of target glycoproteins to profile serum antibodies against melanoma associated antigens that may predict nodal positivity. We identified 5 melanoma-associated antigens using this microarray coupled to mass spectrometry; GRP75, GRP94, ASAH1, CTSD and LDHB. We evaluated their predictive value for nodal status adjusting for age, gender, Breslow thickness, mitotic rate and ulceration using standard logistic regression. After adjustment, ASAH1, CTSD and LDHB were significantly negatively associated with nodal status (P = 0.0008) and GRP94 was significantly positively associated (P = 0.014). Our best multivariate model for nodal positivity included Breslow thickness, presence of serum anti-ASAH1, anti-LDHB or anti-CTSD, and presence of serum anti-GRP94, with an area under the ROC curve of 0.869. If validated, these results show promise for selecting clinically node negative patients for SLN biopsy. In addition, there is strong potential for glycoprotein microarray to screen serum autoantibodies that may identify patients at high risk of distant metastases or those likely or unlikely to respond to treatment, and these proteins may serve as targets for intervention.

Proteomics in melanoma biomarker discovery: great potential, many obstacles

The present clinical staging of melanoma stratifies patients into heterogeneous groups, resulting in the application of aggressive therapies to large populations, diluting impact and increasing toxicity. To move to a new era of therapeutic decisions based on highly specific tumor profiling, the discovery and validation of new prognostic and predictive biomarkers in melanoma is critical. Genomic profiling, which is showing promise in other solid tumors, requires fresh tissue from a large number of primary tumors, and thus faces a unique challenge in melanoma. For this and other reasons, proteomics appears to be an ideal choice for the discovery of new melanoma biomarkers. Several approaches to proteomics have been utilized in the search for clinically relevant biomarkers, but to date the results have been relatively limited. This article will review the present work using both tissue and serum proteomics in the search for melanoma biomarkers, highlighting both the relative advantages and disadvantages of each approach. In addition, we review several of the major obstacles that need to be overcome in order to advance the field.

Autoantibodies to mesothelin in infertility

BACKGROUND

According to extensive epidemiologic data, infertility is associated with increased ovarian cancer risk. Previous studies showed that both women with infertility and those with ovarian cancer have autoantibodies to ovarian antigens. The objective was to determine if women with infertility have antibodies to mesothelin, a well-characterized ovarian cancer antigen.

METHODS

Sera were obtained from women with infertility (n = 109), ovarian cancer (n = 28), benign ovarian tumors or cysts (n = 24), and from healthy women (n = 152). Infertility included those with a risk for ovarian cancer; endometriosis (n = 23), ovulatory dysfunction (n = 17), premature ovarian failure (POF; n = 25) and unexplained infertility (n = 44). Sera were assayed for mesothelin antibodies and for circulating mesothelin antigen by immunoassay and compared with assay control sera (n = 16) to determine a positive result.

RESULTS

Mesothelin antibodies were significantly more frequent in women with prematurely reduced ovarian function including ovulatory dysfunction (59%), ovarian failure (44%) and unexplained infertility (25%) compared with controls. In contrast, women with endometriosis, who also have a high risk for ovarian cancer, did not have mesothelin antibodies. Serum levels of mesothelin were rarely elevated in women with infertility but were high in most patients with ovarian cancer.

CONCLUSIONS AND IMPACT

We show for the first time that antibodies to mesothelin, a well-characterized ovarian cancer antigen, occur in some women with epidemiologic risk for ovarian cancer. The results suggest it may be possible to identify which women with infertility have ovarian cancer risk.

Loss of CD4 T-cell-dependent tolerance to proteins with modified amino acids

The site-specific incorporation of the unnatural amino acid p-nitrophenylalanine (pNO(2)Phe) into autologous proteins overcomes self-tolerance and induces a long-lasting polyclonal IgG antibody response. To determine the molecular mechanism by which such simple modifications to amino acids are able to induce autoantibodies, we incorporated pNO(2)Phe, sulfotyrosine (SO(3)Tyr), and 3-nitrotyrosine (3NO(2)Tyr) at specific sites in murine TNF-α and EGF. A subset of TNF-α and EGF mutants with these nitrated or sulfated residues is highly immunogenic and induces antibodies against the unaltered native protein. Analysis of the immune response to the TNF-α mutants in different strains of mice that are congenic for the H-2 locus indicates that CD4 T-cell recognition is necessary for autoantibody production. IFN-γ ELISPOT analysis of CD4 T cells isolated from vaccinated mice demonstrates that peptides with mutated residues, but not the wild-type residues, are recognized. Immunization of these peptides revealed that a CD4 repertoire exists for the mutated peptides but is lacking for the wild-type peptides and that the mutated residues are processed, loaded, and presented on the I-A(b) molecule. Overall, our results illustrate that, although autoantibodies are generated against the endogenous protein, CD4 cells are activated through a neo-epitope recognition mechanism. Therefore, tolerance is maintained at a CD4 level but is broken at the level of antibody production. Finally, these results suggest that naturally occurring posttranslational modifications such as nitration may play a role in antibody-mediated autoimmune disorders.

Outcome after therapeutic lymph node dissection in patients with unknown primary melanoma site

PURPOSE

The aim of this study was to evaluate the incidence and outcome of melanoma of unknown primary site (MUP) after therapeutic lymph node dissection (TLND) of palpable nodal melanoma metastases. Disease-free (DFS) and overall survival (OS) time of MUP patients were analyzed and compared to patients undergoing a TLND for known primary melanomas (MKP).

METHODS

This single institution retrospective study analyzed 342 consecutive patients who were treated with 415 TLNDs for palpable nodal disease from 1982 to 2009. Univariate and multivariate analyses included: MUP versus MKP, gender, Breslow thickness, ulceration of primary tumor, site of primary tumor, site of dissection, extracapsular extension, number of collected nodes, number of positive nodes and the node positive ratio.

RESULTS

A total of 47 MUP were identified in 342 patients (13.7%). In univariate analysis, a trend was seen toward better survival for MUP patients compared to MKP patients having 5-year OS rates of 40% and 27%, respectively (P = 0.06). Multivariate analysis for OS showed two highly significant factors associated with worse prognosis: extracapsular extension and N3 status (both P < 0.001). Two factors were associated with a significant better prognosis: MUP (P = 0.03) and a neck dissection (P = 0.04).

CONCLUSIONS

Patients with MUP showed a statistically significant better OS compared to patients with melanoma metastases from known primary tumors. Presence of extracapsular extension and an increased number of positive nodes are statistically significantly negative prognostic factors for OS. The absence of a primary melanoma in stage III melanoma patients does not preclude surgery.

Polymorphisms in the CD28/CTLA4/ICOS genes: role in malignant melanoma susceptibility and prognosis?

The appearance of vitiligo and spontaneous regression of the primary lesion in melanoma patients illustrate a relationship between tumor immunity and autoimmunity. T lymphocytes play a major role both in tumor immunity and autoimmunity. CD28, Cytotoxic T lymphocyte antigen 4 (CTLA4) and inducible costimulator (ICOS) molecules are important secondary signal molecules in the T lymphocyte activation. Single nucleotide polymorphisms (SNPs) in the CD28/CTLA4/ICOS gene region were reported to be associated with several autoimmune diseases including, type-1 diabetes, SLE, autoimmune thyroid diseases and celiac disease. In this study, we investigated the association of SNPs in the CD28, CTLA4 and ICOS genes with the risk of melanoma. We also assessed the prognostic effect of the different polymorphisms in melanoma patients. Twenty-four tagging SNPs across the three genes and four additional SNPs were genotyped in a cohort of 763 German melanoma patients and 734 healthy German controls. Influence on prognosis was determined in 587 melanoma cases belonging to stage I or II of the disease. In general, no differences in genotype or allele frequencies were detected between melanoma patients and controls. However, the variant alleles for two polymorphisms in the CD28 gene were differentially distributed in cases and controls. Similarly no association of any polymorphism with prognosis, except for the rs3181098 polymorphism in the CD28 gene, was observed. In addition, individuals with AA genotype for rs11571323 polymorphism in the ICOS gene showed reduced overall survival. However, keeping in view the correction for multiple hypothesis testing our results suggest that the polymorphisms in the CD28, CTLA4 and ICOS genes at least do not modulate risk of melanoma and nor do those influence the disease prognosis in the investigated population.

Autoimmunity and treatment outcome in melanoma

PURPOSE OF REVIEW

Only a subset of melanoma patients with advanced disease seems to benefit from immunotherapy. Predictive markers identifying these patients are unfortunately not available. Whether immune-related side effects could serve as predictors for treatment response or just resemble unwanted side effects from immunotherapy will be outlined in this review.

RECENT FINDINGS

Early studies suggested an association of immune-related side effects such as vitiligo and autoimmune thyroiditis with response in patients receiving IL-2 or IFNα. However, conflicting data have been reported as well, mentioning the effect of a higher rate of immune-related toxicities during prolonged administration of the drug in responders/survivors. This type of bias is also known as guarantee-time bias. Recently, a clearly significant and clinically relevant prolongation of survival was demonstrated in patients with metastatic melanoma treated with ipilimumab. Immune-related adverse events were associated with response to ipilimumab, however, at the cost of considerable toxicity.

SUMMARY

Evidence for an association of immune-related toxicities and response in patients receiving IL-2 or IFNα is weak, considering guarantee-time bias. On the contrary, this association for patients receiving anti-cytotoxic T-lymphocyte antigen-4 therapy (ipilimumab) appears much stronger. Importantly, can we uncouple tumor immunity from autoimmunity in order to optimize immunotherapy in melanoma?

Immunologic functions as prognostic indicators in melanoma

Outcome in melanoma patients with advanced disease is poor and systemic treatment seems to benefit only a subset of patients. Predictive markers identifying these patients are currently not available. Early studies showed an association of immune-related side effects such as vitiligo and autoimmune thyroiditis with response to IL-2 or IFNα treatment. However, conflicting data have been reported as well, mentioning the effect of a higher rate of immune-related toxicities during prolonged administration of the drug in responders. The review discusses the prognostic significance of autoimmunity during various forms of immunotherapy and stresses the importance of correcting for guarantee-time bias. In addition, other immune-related factors which have been associated with melanoma prognosis such as, CRP, white blood cell count, absolute lymphocyte count and human leukocyte antigen will be reviewed as well. A better understanding of the immune system and the host-tumor interactions should ultimately lead to more effective treatment. A major challenge expected to be addressed in future is proving ways to uncouple tumor immunity from autoimmunity.

Skin melanoma development in ret transgenic mice despite the depletion of CD25+Foxp3+ regulatory T cells in lymphoid organs

CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg) known to mediate self-tolerance were also shown to contribute to tumor progression. In mouse melanoma transplantation models, Treg depletion resulted in the stimulation of antitumor immune responses and tumor eradication. To study Treg in conditions close to the clinical situation, we used a ret transgenic mouse spontaneous melanoma model, which, in contrast to transplantation models, resembles human melanoma regarding clinical development. Significantly higher numbers of Treg were found in skin tumors and metastatic lymph nodes at early stages of melanoma progression compared with more advanced stages accompanied by the elevated CCR4 expression on Treg and higher production of its ligand CCL2 in tumor lesions. Numbers of tumor infiltrating Treg inversely correlated with Treg amounts in the bone marrow, suggesting their possible recruitment to melanoma lesions from this organ. The immunosuppressive function of Treg from transgenic tumor-bearing mice was similar to that from transgenic tumor-free mice or nontransgenic littermates. Although anti-CD25 mAb injections resulted in the efficient Treg depletion from lymphoid organs of transgenic mice, melanoma development was not significantly delayed. Furthermore, the treatment of mice with macroscopical tumors also failed to inhibit tumor progression, which correlated with the inability to deplete intratumoral Treg. We suggest that in the autochthonous melanoma genesis, other immunosuppressive cells could play an important role and replace immunosuppressive, tumor-promoting functions of Treg. Therefore, effective melanoma immunotherapy should include the inhibition of Treg migration into the tumor combined with neutralization of other immunosuppressive cells and factors in the tumor microenvironment.

A common repertoire of autoantibodies is shared by cancer and autoimmune disease patients: Inflammation in their induction and impact on tumor growth

The repertoire of autoantibodies found in cancer patients partly overlaps with that typical of patients with autoimmune diseases. Beside the biochemical and immunological properties of the target antigens and their altered expression in tumor tissues, the intratumoral inflammatory context can play a key role in the induction of autoimmune disease-associated autoantibodies in cancer patients. Furthermore, the impact of such antibodies on cancer growth and progression can be deeply influenced by the interplay with inflammation. The characterization of the spontaneous humoral responses occurring in cancer patients, of the mechanisms that trigger and sustain the autoantibody response and of the biological effects of such autoantibodies may help the rational design of anti-cancer immunotherapeutic protocols.

Leukocyte infiltration and tumor cell plasticity are parameters of aggressiveness in primary cutaneous melanoma

Various clinical and experimental observations detected an immunological host defense in cutaneous melanoma. In order to investigate the prognostic value of leukocyte effector mechanisms, we examined the presence of different subsets of leukocytes in tumor samples of 58 patients diagnosed with primary cutaneous melanoma. The presence of T lymphocytes, cytotoxic T lymphocytes, B lymphocytes, CD16+ cells and macrophages was correlated to Breslow depth. A significantly higher amount of several subsets of leukocytes was found in samples with a more progressed tumor stage and survival analysis demonstrated that a higher amount of T lymphocytes and CD16+ cells was associated with a short survival. The amount of FOXP3+ regulatory T lymphocytes did not correlate with survival, nevertheless, it correlated with the amount of total infiltrate. In contrast, analysis of the expression of CD69, a marker for activated lymphocytes, demonstrated that patients with a higher amount of CD69+ lymphocytes had a better survival. In addition, a new parameter for aggressiveness of melanoma, tumor cell plasticity [i.e., the presence of periodic acid Schiff's (PAS) reagent positive loops], also predicted short survival and a trend of a higher amount of tumor infiltrating leukocytes in tumors with PAS positive loops was observed. These findings demonstrate that leukocyte infiltration and the presence of PAS loops is a sign of tumor aggressiveness and may have prognostic value.

Anti-tumor and Anti-ovarian Autoantibodies in Women with Ovarian Cancer

PROBLEM

There is a lack of validated marker(s) for the diagnosis of early-stage ovarian cancer (OVCA). The objective was to determine if women with OVCA had antibodies, to assess their potential as markers of ovarian cancer. The secondary objective was to compare the prevalence of antibodies to proteins from normal ovary and ovarian tumors to determine if antibodies primarily recognize tumor antigens, as many antigens are common to tumor and normal ovary.

METHOD OF STUDY

Serum samples from patients with OVCA, borderline or benign ovarian tumors, endometrial cancer and healthy women were examined for anti-ovarian and anti-tumor antibodies by immunoassay. Immunoreactive proteins were characterized by one- and two-dimensional Western blot.

RESULTS

Ovarian (81%, P < or = 0.001) and anti-tumor (69%, P < or = 0.001) autoantibodies in OVCA were significantly different from those of control sera. A majority of OVCA serum samples reacted with proteins at about 50 kDa from normal ovary or ovarian tumors in one-dimensional Western blot. While there were similar reactions in two-dimensional Western blots, there are differences between reactions to normal and tumor antigens and between reactions to autologous and allogeneic tumors.

CONCLUSION

Serum autoantibodies are significantly associated with OVCA. Anti-tumor antibodies may provide a useful marker for the detection of ovarian cancer.

Lymphocyte activation in response to melanoma: interaction of NK-associated receptors and their ligands

In recent years, studies on the molecular and cellular mechanisms of immune responses against melanoma have contributed to a better understanding of how these tumours can be recognised by cytotoxic cells and the mechanisms they have developed to escape from innate and adaptive immunity. Lysis of melanoma cells by natural killer (NK) cells and cytolytic T cells is the result of a fine balance between signals transmitted by activating and inhibitory receptors. In addition to the T cell receptor, these were initially described as NK cell-associated receptors (NKRs) and were later also found on subsets of T lymphocytes, particularly effector-memory and terminally differentiated CD8 T cells. An increase of NKR(+)CD8(+) T cells has been found in melanoma patients, correlating with the expansion of differentiated effector CD8(+)CD28(null) CD27(null) T cells. NKRs can regulate the lysis of target cells expressing appropriate ligands. Activating receptors recognise ligands on tumours whereas inhibitory receptors are specific for MHC class I antigens and sense missing self. Altered expression of MHC class I antigens is frequently found on melanoma cells, preventing recognition by specific cytolytic T cells but favouring NK cell recognition. Changes in the expression of NKR-ligands in melanoma contribute in explaining the differences in the capacity of cytotoxic immune cells to control melanoma growth and dissemination.

New technologies used in the study of human melanoma

The amount of information on tumor biology has expanded enormously, essentially due to the completion of the human genome sequencing and to the application of new technologies that represent an exciting breakthrough in molecular analysis. Often these data spring from experimental procedures, such as a serial analysis of gene expression (SAGE) and DNA microarrays, which cannot be defined as hypothesis-driven: it may appear to be a "brute force" approach through which no information can be directly generated concerning the specific functions of selected genes in a definite context. However, interesting results are fruitfully generated, and thus it is important to consider the enormous potential these new technologies possess and to learn how to apply this novel form of knowledge in the emerging field of molecular medicine. This review, after a limited outline regarding several classic aspects of human cutaneous melanoma biology, genetics, and clinical approaches, will focus on the proficient use of up-to-date technologies in the study of the neoplastic disease and on their capability to provide effective support to conventional approaches in melanoma diagnosis, prognosis, and treatment.

Tumour immunity and T cell memory are induced by low dose inoculation with a non-replicating adenovirus encoding TAP1

Despite continued progress in understanding the pathophysiology of tumours, curative therapeutic options are still lacking for the metastatic form of the disease. One approach that has gathered considerable interest is the creation of therapeutic vaccines using genetically engineered non-replicating viruses as vehicles to revive immunosurveillance mechanisms that may eradicate residual tumour cells. A perceived problem with this approach is that the number of non-replicating viruses used as a vaccine inoculum does not remotely approximate the total number of cells in the body, nor even the number of tumour cells in the case of large tumour burden or metastasis. Here, we addressed the hypothesis that a limited amount of inoculum (1x10(8) PFU) of recombinant non-replicating adenovirus encoding human TAP1 (AdhTAP1) can induce protective immunity against 1.5x10(5) TAP-deficient, metastatic melanoma cells transplanted into a normal mouse (total of approximately 1x10(11) body cells). We show that efficacious anti-tumour cytolytic T cell responses are indeed induced by injecting melanoma-bearing animals with small numbers of recombinant viruses, resulting in increases in tumour-infiltrating dendritic cells, enhanced memory T cell subpopulations and, most importantly, in increased animal survival. This novel approach uses a limited input inoculum relative to the tumour cell mass, and thus achieves an efficacious outcome that has so far eluded other vaccine, immunotherapeutic or gene therapeutic strategies where there is a requisite for the majority of tumour cells to be transduced for beneficial outcome to be achieved.

Identification of alpha-enolase as an autoantigen in lung cancer: its overexpression is associated with clinical outcomes

PURPOSE

Although existence of humoral immunity has been previously shown in malignant pleural effusions, only a limited number of immunogenic tumor-associated antigens (TAA) have been identified and associated with lung cancer. In this study, we intended to identify more TAAs in pleural effusion-derived tumor cells.

EXPERIMENTAL DESIGN

Using morphologically normal lung tissues as a control lysate in Western blotting analyses, 54 tumor samples were screened with autologous effusion antibodies. Biochemical purification and mass spectrometric identification of TAAs were done using established effusion tumor cell lines as antigen sources. We identified a p48 antigen as alpha-enolase (ENO1). Semiquantitative immunohistochemistry was used to evaluate expression status of ENO1 in the tissue samples of 80 patients with non-small cell lung cancer (NSCLC) and then correlated with clinical variables.

RESULTS

Using ENO1-specifc antiserum, up-regulation of ENO1 expression in effusion tumor cells from 11 of 17 patients was clearly observed compared with human normal lung primary epithelial and non-cancer-associated effusion cells. Immunohistochemical studies consistently showed high level of ENO1 expression in all the tumors we have examined thus far. Log-rank and Cox's analyses of ENO1 expression status revealed that its expression level in primary tumors was a key factor contributing to overall- and progression-free survivals of patients (P < 0.05). The same result was also obtained in the early stage of NSCLC patients, showing that tumors expressing relatively higher ENO1 level were tightly correlated with poorer survival outcomes.

CONCLUSIONS

Our data strongly support a prognostic role of ENO1 in determining tumor malignancy of patients with NSCLC.

Combination therapy with anti-CTL antigen-4 and anti-4-1BB antibodies enhances cancer immunity and reduces autoimmunity

The majority of cancer antigens identified thus far have limited expression in normal tissues. It has been suggested that autoimmune disease is a necessary price for cancer immunity. This notion is supported by a recent clinical trial involving an anti-CTL antigen-4 (CTLA-4) antibody that showed significant clinical responses but severe autoimmune diseases in melanoma patients. To selectively modulate cancer immunity and autoimmunity, we used anti-CTLA-4 and anti-4-1BB antibodies to treat mice with a preexisting cancer, MC38. The combination of the two antibodies led to CD8 T-cell-mediated rejection of large established MC38 tumors and long-lasting immunity to the same tumor cells, although the same regimen was not effective for B16 melanoma. More importantly, whereas individual antibodies induced inflammation and autoimmune manifestations, combination therapy increased cancer immunity while reducing autoimmunity. The reduction of autoimmune effects correlates with an increased function of regulatory T cells. Our results suggest a novel approach to simultaneously enhance cancer immunity and reduce autoimmunity.

CD4 T Cell-Dependent Autoimmunity against a Melanocyte Neoantigen Induces Spontaneous Vitiligo and Depends upon Fas-Fas Ligand Interactions

Better understanding of tolerance and autoimmunity toward melanocyte-specific Ags is needed to develop effective treatment for vitiligo and malignant melanoma; yet, a systematic assessment of these mechanisms has been hampered by the difficulty in tracking autoreactive T cells. To address this issue, we have generated transgenic mice that express hen egg lysozyme as a melanocyte-specific neoantigen. By crossing these animals to a hen egg lysozyme-specific CD4 TCR transgenic line we have been able to track autoreactive CD4+ T cells from their development in the thymus to their involvement in spontaneous autoimmune disease with striking similarity to human vitiligo vulgaris and Vogt-Koyanagi-Harada syndrome. Our findings show that CD4-dependent destruction of melanocytes is partially inhibited by blocking Fas-Fas ligand interactions and also highlights the importance of local control of autoimmunity, as vitiligo remains patchy and never proceeds to confluence even when Ag and autoreactive CD4+ T cells are abundant. Immune therapy to enhance or suppress melanocyte-specific T cells can be directed at a series of semiredundant pathways involving tolerance and cell death.