Induction of immune response against NY-ESO-1 by CHP-NY-ESO-1 vaccination and immune regulation in a melanoma patient

A Vaccine against Cancer: Can There Be a Possible Strategy to Face the Challenge? Possible Targets and Paradoxical Effects

Is it possible to have an available vaccine that eradicates cancer? Starting from this question, this article tries to verify the state of the art, proposing a different approach to the issue. The variety of cancers and different and often unknown causes of cancer impede, except in some cited cases, the creation of a classical vaccine directed at the causative agent. The efforts of the scientific community are oriented toward stimulating the immune systems of patients, thereby preventing immune evasion, and heightening chemotherapeutic agents effects against cancer. However, the results are not decisive, because without any warning signs, metastasis often occurs. The purpose of this paper is to elaborate on a vaccine that must be administered to a patient in order to prevent metastasis; metastasis is an event that leads to death, and thus, preventing it could transform cancer into a chronic disease. We underline the fact that the field has not been studied in depth, and that the complexity of metastatic processes should not be underestimated. Then, with the aim of identifying the target of a cancer vaccine, we draw attention to the presence of the paradoxical actions of different mechanisms, pathways, molecules, and immune and non-immune cells characteristic of the tumor microenvironment at the primary site and pre-metastatic niche in order to exclude possible vaccine candidates that have opposite effects/behaviors; after a meticulous evaluation, we propose possible targets to develop a metastasis-targeting vaccine. We conclude that a change in the current concept of a cancer vaccine is needed, and the efforts of the scientific community should be redirected toward a metastasis-targeting vaccine, with the increasing hope of eradicating cancer.

Recent Trends in Biosensing and Diagnostic Methods for Novel Cancer Biomarkers

Cancer is one of the major public health issues in the world. It has become the second leading cause of death, with approximately 75% of cancer deaths transpiring in low- or middle-income countries. It causes a heavy global economic cost estimated at more than a trillion dollars per year. The most common cancers are breast, colon, rectum, prostate, and lung cancers. Many of these cancers can be treated effectively and cured if detected at the primary stage. Nowadays, around 50% of cancers are detected at late stages, leading to serious health complications and death. Early diagnosis of cancer diseases substantially increases the efficient treatment and high chances of survival. Biosensors are one of the potential screening methodologies useful in the early screening of cancer biomarkers. This review summarizes the recent findings about novel cancer biomarkers and their advantages over traditional biomarkers, and novel biosensing and diagnostic methods for them; thus, this review may be helpful in the early recognition and monitoring of treatment response of various human cancers.

Immunological response of polysaccharide nanogel-incorporating PEG hydrogels in an in vivo diabetic model

Cell-based therapies hold significant advantages in comparison with the traditional drug-based or injection-based treatments. However, for long-term functional cellular implants, immune acceptance must be established. To accomplish the acceptance of the implanted cells, various biomaterial systems have been studied. Nanogels have shown great potential for modulation of cellular microenvironments, acting as a physical barrier between the immune system and the implant. However, internalization of nano-scale materials by implanted cells is not desirable and is yet to be overcome. In this study, we incorporated acrylate modified cholesterol-bearing pullulan (CHPOA) nanogels into poly (ethylene glycol) diacrylate (PEGDA) hydrogels through covalent crosslinking, where we used visible light-induced photopolymerization. We characterized morphology and swelling properties of CHPOA incorporated PEG composite hydrogels using FE-SEM and gravimetric analysis. Also, we investigated the biocompatibility properties of composite hydrogels in vivo, where we used both healthy and diabetic mice. We induced diabetes in mice using a low dose streptozotocin (STZ) injections and implanted composite hydrogels in both diabetic and healthy mice through subcutaneous route. Immune cell infiltration of the retrieved tissue was examined through histological analysis, where we observed minimum immune response levels of 0-2 rareness, according to ISO standard of biological evaluation of medical devices. Our observation suggests that the composite hydrogel developed here can be used to introduce nanostructured domains into bulk hydrogels and that this system has potential to be used as immunologically acceptable composite material in cellular therapy without internalization of nanoparticles.

Nanogels as target drug delivery systems in cancer therapy: A review of the last decade

Cancer is an important cause of morbidity and mortality worldwide, irrespective of the level of human development. Globally, it was estimated that there were 19.3 million new cases of cancer and almost 10 million deaths from cancer in 2020. The importance of prevention, early detection as well as effective cancer therapies cannot be over-emphasized. One of the important strategies in cancer therapy is targeted drug delivery to the specific tumor sites. Nanogels are among the several drug delivery systems (DDS) being explored as potential candidates for targeted drug delivery in cancer therapy. Nanogels, which are new generation, versatile DDS with the possession of dual characteristics of hydrogels and nanoparticles have shown great potential as targeted DDS in cancer therapy. Nanogels are hydrogels with a three-dimensional (3D) tunable porous structure and a particle size in the nanometre range, from 20 to 200 nm. They have been visualized as ideal DDS with enormous drug loading capacity, and high stability. Nanogels can be modified to achieve active targeting and enhance drug accumulation in disease sites. They can be designed to be stimulus-responsive, and react to internal or external stimuli such as pH, temperature, light, redox, thus resulting in the controlled release of loaded drug. This prevents drug accumulation in non-target tissues and minimizes the side effects of the drug. Drugs with severe adverse effects, short circulation half-life, and easy degradability by enzymes, such as anti-cancer drugs, and proteins, are suitable for delivery by chemically cross-linked or physically assembled nanogel systems. This systematic review summarizes the evolution of nanogels for targeted drug delivery for cancer therapy over the last decade. On-going clinical trials and recent applications of nanogels as targeted DDS for cancer therapy will be discussed in detail. The review will be concluded with discussions on safety and regulatory considerations as well as future research prospects of nanogel-targeted drug delivery for cancer therapy.

Lymph node-targeted neoantigen nanovaccines potentiate anti-tumor immune responses of post-surgical melanoma

Background

Neoantigens are considered ideal targets for immunotherapy, especially tumor vaccine, because of their strong specificity and immunogenicity. Here, we developed a neoantigen nanovaccine used liposomes with lymph-node targeting characteristic.

Methods

Our nanovaccine was composed of neoantigens, an amphiphilic liposome and an adjuvant Montanide™ ISA 51. Small animal imaging system and immunofluorescence staining were used to identify the distribution of nanovaccines. A subcutaneous-tumor-resection mouse model of melanoma was established to evaluate the anti-tumor efficacy. Flow cytometry was performed to assay the immune responses initiated by nanovaccines.

Results

Nanovaccines could traffic to lymph nodes, be uptaken by CD11c⁺ DCs and promote DCs maturity. After the treatment of our neoantigen nanovaccines, the average recurrence time was extended from 11 to 16 days and the median survival time was even prolonged 7.5 days relative to the control group (NS group). Nanovaccines increased neoantigen-specific T cells to 10-fold of free vaccines, and upregulated Th1 cytokines, such as IFN-γ and TNF-α. The anti-tumor activity of spleen lymphocytes in the nanovaccine group was significantly stronger than that of other groups. However, some immune-inhibitory cells or molecules in tumor microenvironment have been detected upregulated under the immune pressure of neoantigen nanovaccines, such as Tregs and PD-L1. The efficacy of the neoantigen nanovaccine combined with anti-PD1 antibody or Treg inhibiting peptide P60 was better than that of the single treatment.

Conclusions

We developed a general vaccine strategy, triggering specific T cell responses, and provided feasible combination strategies for better anti-tumor efficacy.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01397-7.

Therapeutic cancer vaccines

Therapeutic cancer vaccines have undergone a resurgence in the past decade. A better understanding of the breadth of tumour-associated antigens, the native immune response and development of novel technologies for antigen delivery has facilitated improved vaccine design. The goal of therapeutic cancer vaccines is to induce tumour regression, eradicate minimal residual disease, establish lasting antitumour memory and avoid non-specific or adverse reactions. However, tumour-induced immunosuppression and immunoresistance pose significant challenges to achieving this goal. In this Review, we deliberate on how to improve and expand the antigen repertoire for vaccines, consider developments in vaccine platforms and explore antigen-agnostic in situ vaccines. Furthermore, we summarize the reasons for failure of cancer vaccines in the past and provide an overview of various mechanisms of resistance posed by the tumour. Finally, we propose strategies for combining suitable vaccine platforms with novel immunomodulatory approaches and standard-of-care treatments for overcoming tumour resistance and enhancing clinical efficacy.

First-in-human phase I clinical trial of the NY-ESO-1 protein cancer vaccine with NOD2 and TLR9 stimulants in patients with NY-ESO-1-expressing refractory solid tumors

Cholesteryl pullulan (CHP) is a novel antigen delivery system. CHP and New York esophageal squamous cell carcinoma 1 (NY-ESO-1) antigen complexes (CHP-NY-ESO-1) present multiple epitope peptides to the MHC class I and II pathways. Adjuvants are essential for cancer vaccines. MIS416 is a non-toxic microparticle that activates immunity via the nucleotide-binding oligomerization domain 2 (NOD2) and TLR9 pathways. However, no reports have explored MIS416 as a cancer vaccine adjuvant. We conducted a first-in-human clinical trial of CHP-NY-ESO-1 with MIS416 in patients with NY-ESO-1-expressing refractory solid tumors. CHP-NY-ESO-1/MIS416 (μg/μg) was administered at 100/200, 200/200, 200/400 or 200/600 (cohorts 1, 2, 3 and 4, respectively) every 2 weeks for a total of 6 doses (treatment phase) followed by one vaccination every 4 weeks until disease progression or unacceptable toxicity (maintenance phase). The primary endpoints were safety and tolerability, and the secondary endpoint was the immune response. In total, 26 patients were enrolled. Seven patients (38%) continued vaccination in the maintenance phase. Grade 3 drug-related adverse events (AEs) were observed in six patients (23%): anorexia and hypertension were observed in one and five patients, respectively. No grade 4–5 drug-related AEs were observed. Eight patients (31%) had stable disease (SD). Neither augmentation of the NY-ESO-1-specific IFN-γ-secreting CD8⁺ T cell response nor an increase in the level of anti-NY-ESO-1 IgG1 was observed as the dose of MIS416 was increased. In a preclinical study, adding anti-PD-1 monoclonal antibody to CHP-NY-ESO-1 and MIS416 induced significant tumor suppression. This combination therapy is a promising next step.

Nanogelation and Thermal Stabilization of Enzyme by Vitamin B6-Bearing Polysaccharide as Biocrosslinker

Nanogels containing a protein (carbonic anhydrase, CA) were prepared by cross-linking CA and pyridoxal (vitamin B₆)-bearing pullulan (PLPP) as a biocrosslinker via Schiff base formation. UV titration and high-performance liquid chromatography confirmed that CA was quantitatively complexed with PLPP in the presence of zinc ions. Dynamic light scattering and transmission electron microscopy showed that the nanogel diameter was about 20 nm. CA retained 90% of its native activity after complexation with PLPP. Moreover, the residual enzymatic activity of CA after heating and its long-term storage stability at room temperature were improved by complexation with PLPP. Enzyme nanogelation with PLPP is an efficient method for enzyme stabilization.

Research progress of self-assembled nanogel and hybrid hydrogel systems based on pullulan derivatives

Polymer nano-sized hydrogels (nanogels) as drug delivery carriers have been investigated over the last few decades. Pullulan, a nontoxic and nonimmunogenic hydrophilic polysaccharide derived from fermentation of black yeast like Aureobasidium pullulans with great biocompatibility and biodegradability, is one of the most attractive carriers for drug delivery systems. In this review, we describe the preparation, characterization, and 'switch-on/off' mechanism of typical pullulan self-assembled nanogels (self-nanogels), and then introduce the development of hybrid hydrogels that are numerous resources applied for regenerative medicine. A major section is used for biomedical applications of different nanogel systems based on modified pullulan, which exert smart stimuli-responses at ambient conditions such as charge, pH, temperature, light, and redox. Pullulan self-nanogels have found increasingly extensive application in protein delivery, tissue engineering, vaccine development, cancer therapy, and biological imaging. Functional groups are incorporated into self-nanogels and contribute to expressing desirable results such as targeting and modified release. Various molecules, especially insoluble or unstable drugs and encapsulated proteins, present improved solubility and bioavailability as well as reduced side effects when incorporated into self-nanogels. Finally, the advantages and disadvantages of pullulan self-nanogels will be analyzed accordingly, and the development of pullulan nanogel systems will be reviewed.

Detection of autoantibodies against cancer-testis antigens in non-small cell lung cancer

OBJECTIVES

Cancer-testis antigens (CTAs) are defined as proteins that are specifically expressed in testis or placenta and their expression is frequently activated in cancer. Due to their ability to induce an immune response, CTAs may serve as suitable targets for immunotherapy. The aim of this study was to evaluate if there is reactivity against CTAs in the plasma of non-small cell lung cancer (NSCLC) patients through the detection of circulating antibodies.

MATERIALS AND METHODS

To comprehensively analyze autoantibodies against CTAs the multiplexing capacities of suspension bead array technology was used. Bead arrays were created with 120 protein fragments, representing 112 CTAs. Reactivity profiles were measured in plasma samples from 133 NSCLC patients and 57 cases with benign lung diseases.

RESULTS

Altogether reactivity against 69 antigens, representing 81 CTAs, was demonstrated in at least one of the analyzed samples. Twenty-nine of the antigens (45 CTAs) demonstrated exclusive reactivity in NSCLC samples. Reactivity against cancer-testis antigen family 47; member A (CT47A) genes, P antigen family member 3 (PAGE3), variable charge X-linked (VCX), melanoma antigen family B1 (MAGEB1), lin-28 homolog B (LIN28B) and chromosome 12 open reading frame 54 (C12orf54) were only found in NSCLC patients at a frequency of 1%-4%. The presence of autoantibodies towards these six antigens was confirmed in an independent group of 34 NSCLC patients.

CONCLUSION

We identified autoantibodies against CTAs in the plasma of lung cancer patients. The reactivity pattern of autoantibodies was higher in cancer patients compared to the benign group, stable over time, but low in frequency of occurrence. The findings suggest that some CTAs are immunogenic and that these properties can be utilized as immune targets.

Sequential Coating of Insulin Secreting Beta Cells within Multilayers of Polysaccharide Nanogels

Pancreatic islet transplantation has emerged as a promising treatment for type-1 diabetes (T1D); however, its clinical application is still limited by the life-long use of immunosuppressive drugs, insufficient number of islets to achieve normoglycemia, and large transplantation volume. This paper reports a unique approach for nanothin coating of insulin secreting beta cell aggregates. The coating is based on hydrophobic and covalent interactions between natural acrylate modified cholesterol bearing pullulan (CHPOA) nanogels and MIN6 beta cell aggregates. Beta cell aggregates are prepared as spheroids through hanging drop method, which is optimized with respect to hanging drop volume and initial number of beta cells. These aggregates, defined as pseudoislets, are coated with sequential layers of nanogels and are evaluated as viable and functional for insulin secretion. Coating experiments are carried out using physiologically compatible medium, where pseudoislets are not brought in contact with toxic prepolymer solutions used in existing approaches. This study offers new opportunities through coating of islets with advanced functional materials under completely physiological conditions for clinical translation of cell transplantation technology. The technique developed here will establish a new paradigm for creating tolerable grafts for other chronic diseases such as anemia, cancer, central nervous system (CNS) diseases.

NY-ESO-1 Protein Cancer Vaccine With Poly-ICLC and OK-432: Rapid and Strong Induction of NY-ESO-1-specific Immune Responses by Poly-ICLC

We conducted a clinical trial of a cancer vaccine using NY-ESO-1 protein with polyinosinic-polycytidylic acid-poly-L-lysine carboxymethylcellulose (poly-ICLC) and/or OK-432 against solid tumors. A total of 15 patients were sequentially enrolled in 4 cohorts. Patients in cohort 1 received NY-ESO-1 protein; cohort 2a received NY-ESO-1 protein+OK-432; cohort 2b received NY-ESO-1 protein+poly-ICLC; cohort 3 received NY-ESO-1 protein+OK-432+poly-ICLC with Montanide ISA-51. The endpoints of this trial were safety, NY-ESO-1 immune responses, and clinical response. Vaccine-related adverse events observed were fever and injection-site reaction (grade 1). Two patients showed stable disease after vaccination. NY-ESO-1 antibodies were observed in 4 patients at the baseline (sero-positive) and augmented in all patients after vaccination. Eleven patients showed a conversion of negative antibody responses at baseline to positive after vaccination (seroconversion). The seroconversions were observed in all 11 sero-negative patients by the fourth immunization; in particular, it was observed by the second immunization in patients with poly-ICLC, and these induced antibody responses were stronger than those in patients immunized without poly-ICLC. The number of NY-ESO-1-specific interferon (IFN)γ-producing T cells was increased in patients immunized with poly-ICLC and/or OK-432, and furthermore, the increase of IFNγ-producing CD8 T cells in patients immunized with poly-ICLC was significantly higher than that in patients without poly-ICLC. Nonspecific activations of T-cell or antigen presenting cells were not observed. Our present study showed that poly-ICLC is a promising adjuvant for cancer vaccines.

Translational nanoparticle engineering for cancer vaccines

Conventional cancer treatments remain insufficient to treat many therapy-resistant tumors.¹ Cancer vaccines attempt to overcome this resistance by activating the patient's immune system to eliminate tumor cells without the toxicity of systemic chemotherapy and radiation. Nanoparticles (NPs) are promising as customizable, immunostimulatory carriers to protect and deliver antigen. Although many NP vaccines have been investigated in preclinical settings, a few have advanced into clinical application, and still fewer have demonstrated clinical benefit. This review incorporates observations from NP vaccines that have been evaluated in early phase clinical trials to make recommendations for the next generation of NP-based cancer vaccines.

Selection of epitopes from self-antigens for eliciting Th2 or Th1 activity in the treatment of autoimmune disease or cancer

Vaccines have been valuable tools in the prevention of infectious diseases, and the rapid development of new vectors against constantly mutating foreign antigens in viruses such as influenza has become a regular, seasonal exercise. Harnessing the immune response against self-antigens is not necessarily analogous or as achievable by iterative processes, and since the desired outcome includes leaving the targeted organism intact, requires some precision engineering. In vaccine-based treatment of autoimmunity and cancer, the proper selection of antigens and generation of the desired antigen-specific therapeutic immunity has been challenging. Both cases involve a threshold of existing, undesired immunity that must be overcome, and despite considerable academic and industry efforts, this challenge has proven to be largely refractory to vaccine approaches leveraging enhanced vectors, adjuvants, and administration strategies. There are in silico approaches in development for predicting the immunogenicity of self-antigen epitopes, which are being validated slowly. One simple approach showing promise is the functional screening of self-antigen epitopes for selective Th1 antitumor immunogenicity, or inversely, selective Th2 immunogenicity for treatment of autoimmune inflammation. The approach reveals the importance of confirming both Th1 and Th2 components of a vaccine immunogen; the two can confound one another if not parsed but may be used individually to modulate antigen-specific inflammation in autoimmune disease or cancer.

Nanogel containing electrospun nanofibers as a platform for stable loading of proteins

We designed polysaccharide nanogel-containing nanofibers by electrospinning. This system have a great potential for protein delivery systems.

Current advances in self-assembled nanogel delivery systems for immunotherapy

Since nanogels (nanometer-sized gels) were developed two decades ago, they were utilized as carriers of innovative drug delivery systems. In particular, immunological drug delivery via self-assembled nanogels (self-nanogels) owing to their nanometer size and molecular chaperon-like ability to encapsulate large biomolecules is one of the most well studied and successful applications of nanogels. In the present review, we focus on self-nanogel applications as immunological drug delivery systems for cancer vaccines, cytokine delivery, nasal vaccines, and nucleic acid delivery, including several clinical trials. Cancer vaccines were the first practical application of self-nanogels as vehicles for drug delivery. After successful pre-clinical studies, phase I clinical trials were conducted, and it was found that vaccines consisting of self-nanogels could be administered repeatedly to humans without serious adverse effects, and self-nanogel vaccines induced antigen-specific cellular and humoral immunity. Cytokine delivery via self-nanogels led to the sustained release of IL-12, suppressed tumor growth, and increased Th1-type immune responses. Cationic self-nanogels were effective in penetrating the nasal mucosa and resulted in successful nasal vaccines in mice and nonhuman primates. Cationic self-nanogels were also used for the intracellular delivery of proteins and nucleic acids, and were successfully used to knockdown tumor growth factor expression using short interfering RNA with the immunological effect. These studies suggest that self-nanogels are currently one of the most unique and attractive immunological drug delivery systems and are edging closer to practical use.

High expression of MAGE-A4 and MHC class I antigens in tumor cells and induction of MAGE-A4 immune responses are prognostic markers of CHP-MAGE-A4 cancer vaccine

PURPOSE

We conducted a cancer vaccine clinical trial with MAGE-A4 protein. Safety, clinical response, and antigen-specific immune responses were analyzed and the prognostic factors by vaccination were investigated.

EXPERIMENTAL DESIGN

Twenty patients with advanced esophageal, stomach or lung cancer were administered MAGE-A4 vaccine containing 300μg protein subcutaneously once every 2 weeks in six doses. Primary endpoints of this study were safety and MAGE-A4 immune responses.

RESULTS

The vaccine was well tolerated. Fifteen of 20 patients completed one cycle of vaccination and two patients showed SD. A MAGE-A4-specific humoral immune response was observed in four patients who had high expression of MAGE-A4 and MHC class I on tumor cells. These four patients showed significantly longer overall survival than patients without an antibody response after vaccination (p=0.009). Patients with tumor cells expressing high MAGE-A4 or MHC class I antigen showed significantly longer overall survival than those with low expression. Induction of CD4 and CD8T cell responses was observed in three and six patients, respectively, and patients with induction of MAGE-A4-specific IFNγ-producing CD8T cells, but not CD4T cells, lived longer than those without induction.

CONCLUSIONS

The CHP-MAGE-A4 vaccine was safe. Expression of MAGE-A4 and MHC class I in tumor tissue and the induction of a MAGE-A4-specific immune response after vaccination would be feasible prognostic markers for patients vaccinated with MAGE-A4.

Evolving role of tumor antigens for future melanoma therapies

ABSTRACT: 

Human tumor rejection antigens recognized by T lymphocytes were first defined in the early 1990s and the identification of shared tumor-restricted antigens sparked hopes for the development of a therapeutic vaccination to treat cancer, including melanoma. Despite decades of intense preclinical and clinical research, the success of anticancer vaccines based on these antigens has been limited. While melanoma is a highly immunogenic tumor, the ability to prime immunity with vaccines has not generally translated into objective disease regression. However, with the development of small molecules targeting oncogenic proteins, such as V600-mutated BRAF, and immune checkpoint inhibitors with demonstrable long-lasting clinical benefit, new opportunities for antigen-targeted directed therapies are emerging.

Engineering synthetic vaccines using cues from natural immunity

Vaccines aim to protect against or treat diseases through manipulation of the immune response, promoting either immunity or tolerance. In the former case, vaccines generate antibodies and T cells poised to protect against future pathogen encounter or attack diseased cells such as tumours; in the latter case, which is far less developed, vaccines block pathogenic autoreactive T cells and autoantibodies that target self tissue. Enormous challenges remain, however, as a consequence of our incomplete understanding of human immunity. A rapidly growing field of research is the design of vaccines based on synthetic materials to target organs, tissues, cells or intracellular compartments; to co-deliver immunomodulatory signals that control the quality of the immune response; or to act directly as immune regulators. There exists great potential for well-defined materials to further our understanding of immunity. Here we describe recent advances in the design of synthetic materials to direct immune responses, highlighting successes and challenges in prophylactic, therapeutic and tolerance-inducing vaccines.

Cohesin complexes with a potential to link mammalian meiosis to cancer

Among multiple genes aberrantly activated in cancers, invariably, there is a group related to the capacity of cell to self-renewal. Some of these genes are related to the normal process of development, including the establishment of a germline. This group, a part of growing family of Cancer/Testis (CT) genes, now includes the meiosis specific subunits of cohesin complex. The first reports characterizing the SMC1 and RAD21 genes, encoding subunits of cohesin, were published 20 years ago; however the exact molecular mechanics of cohesin molecular machine in vivo remains rather obscure notwithstanding ample elegant experiments. The matters are complicated by the fact that the evolution of cohesin function, which is served by just two basic types of protein complexes in budding yeast, took an explosive turn in Metazoa. The recent characterization of a new set of genes encoding cohesin subunits specific for meiosis in vertebrates adds several levels of complexity to the task of structure-function analysis of specific cohesin pathways, even more so in relation to their aberrant functionality in cancers. These three proteins, SMC1β, RAD21L and STAG3 are likely involved in a specific function in the first meiotic prophase, genetic recombination, and segregation of homologues. However, at present, it is rather challenging to pinpoint the molecular role of these proteins, particularly in synaptonemal complex or centromere function, due to the multiplicity of different cohesins in meiosis. The roles of these proteins in cancer cell physiology, upon their aberrant activation in tumors, also remain to be elucidated. Nevertheless, as the existence of Cancer/Testis cohesin complexes in tumor cells appears to be all but certain, this brings a promise of a new target for cancer therapy and/or diagnostics.

A hybrid hydrogel biomaterial by nanogel engineering: bottom-up design with nanogel and liposome building blocks to develop a multidrug delivery system

New hybrid poly(ethylene glycol) (PEG) hydrogels crosslinked with both nanogels and nanogel-coated liposome complexes are obtained by Michael addition of the acryloyl group of a cholesterol-bearing pullulan (CHP) nanogel to the thiol group of pentaerythritol tetra(mercaptoethyl) polyoxyethylene. The nanogel-coated liposome complex is stably retained after gelation and the complexes are well dispersed in the hybrid gel. Microrheological measurements show that the strength and gelation time of the hybrid hydrogel can be controlled by changing the liposome:nanogel ratio. The hydrogel is gradually degraded by hydrolysis under physiological conditions. In this process, the nanogel is released first, followed by the nanogel-coated liposomes. Hybrid hydrogels that can incorporate various molecules into the nanogel and liposomes, and release them in a two-step controllable manner, represent a new functional scaffold capable of delivering multiple drugs, proteins or DNA.

Lessons from cancer immunoediting in cutaneous melanoma

We will revisit the dual role of the immune system in controlling and enabling tumor progression, known as cancer immunoediting. We will go through the different phases of this phenomenon, exposing the most relevant evidences obtained from experimental models and human clinical data, with special focus on Cutaneous Melanoma, an immunogenic tumor per excellence. We will describe the different immunotherapeutic strategies employed and consider current models accounting for tumor heterogeneity. And finally, we will propose a rational discussion of the progress made and the future challenges in the therapeutics of Cutaneous Melanoma, taking into consideration that tumor evolution is the resulting from a continuous feedback between tumor cells and their environment, and that different combinatorial therapeutic approaches can be implemented according to the tumor stage.

Self-assembling CpG DNA nanoparticles for efficient antigen delivery and immunostimulation

DNA containing unmethylated deoxycytidylyl-deoxyguanosine (CpG) dinucleotides (CpG DNA) is a potent stimulator of immune responses through triggering of Toll-like receptor 9 (TLR9). In the present study, we synthesized cholesterol-modified CpG oligodeoxynucleotide (Chol-CpG ODN) and investigated its ability to form nanoparticles by self-assembling, then examined their immunostimulatory activity and potency to deliver antigens to antigen presenting cells (APCs). Chol-CpG ODN spontaneously formed particles in aqueous solutions. Cholesterol modification increased the stability of ODN in serum. Chol-CpG ODN was efficiently taken up by mouse macrophage-like RAW264.7 cells and induced a large amount of tumor necrosis factor-α compared with unmodified CpG ODN. Then, ovalbumin (OVA), a model antigen, was incorporated into Chol-CpG ODN nanoparticles. Cholesterol-modified GpC ODN (Chol-GpC ODN) was used to assess the importance of CpG motif on the antigen-specific immune response. Vaccination of mice with OVA/Chol-CpG ODN induced high level interferon-γ production from splenocytes. Furthermore, a high serum level of OVA-specific immunoglobulin G2a was observed in mice receiving OVA/Chol-CpG ODN. Neither CpG ODN nor Chol-GpC ODN was effective at all. These results indicate that self-assembling nanoparticles of Chol-CpG ODN are effective for inducing antigen-specific immune responses because of the high immunostimulatory activity, ability to incorporate antigens and tropism to APCs.

Expression profile of cancer-testis genes in transitional cell carcinoma of the bladder

OBJECTIVES

To explore the expression profile of multiple cancer testis (CT) genes in transitional cell carcinoma of bladder (TCC), and investigate its possible correlation with clinicopathologic characteristics.

METHODS

The mRNA expression of 6 CT genes was detected using reverse transcription polymerase chain reaction (RT-PCR) for 102 TCC samples (59 Ta-T1, 43 T2-T4, 44 G1, 32 G2, and 26 G3 samples) as well as the matching adjacent normal bladder mucosa for each sample. The MAGE-A3 protein expression was also determined by immunoblotting. Immunohistochemistry was performed in selected samples to confirm the MAGE-A3 protein expression.

RESULTS

The mRNA expression of all 6 CT genes was detected with relatively high frequencies in TCC tissues. The percent of samples positive for each gene in the TCC samples are: MAGE-A3, 58.8%; MAGE-A1, 56.9%; cTAGE-1, 52.9%; MAGE-A12, 51%; cTAGE-2, 49%; and NY-ESO-1, 45.1%. Furthermore, MAGE-A3 protein expression was positive in 52.9% of TCC tissues by immunoblotting. Immunohistochemistry showed an exclusively cytoplasmic staining pattern of MAGE-A3 protein. Neither CT gene mRNA expression nor MAGE-A3 protein expression was found in the adjacent normal tissue. There was no significant correlation between CT gene expression and clinicopathologic characteristics (P > 0.05).

CONCLUSIONS

All six CT genes are highly expressed in TCC, and may serve as therapeutic targets of specific immunotherapy for TCC, especially in multi-antigen vaccine preparations.

Vaccines targeting the neovasculature of tumors

Angiogenesis has a critical role in physiologic and disease processes. For the growth of tumors, angiogenesis must occur to carry sufficient nutrients to the tumor. In addition to growth, development of new blood vessels is necessary for invasion and metastases of the tumor. A number of strategies have been developed to inhibit tumor angiogenesis and further understanding of the interplay between tumors and angiogenesis should allow new approaches and advances in angiogenic therapy. One such promising angiogenic approach is to target and inhibit angiogenesis with vaccines. This review will discuss recent advances and future prospects in vaccines targeting aberrant angiogenesis of tumors. The strategies utilized by investigators have included whole endothelial cell vaccines as well as vaccines with defined targets on endothelial cells and pericytes of the developing tumor endothelium. To date, several promising anti-angiogenic vaccine strategies have demonstrated marked inhibition of tumor growth in pre-clinical trials with some showing no observed interference with physiologic angiogenic processes such as wound healing and fertility.

Amphiphilic polysaccharide nanoballs: a new building block for nanogel biomedical engineering and artificial chaperones

Enzymatically synthesized glycogen (ESG), a highly branched (1→4)(1→6)-linked α-glucan, is a new monodisperse spherical hyperbranched nanoparticle (molecular weight, 10(6)-10(7); diameter, 20-30 nm), polysaccharide nanoball. Amphiphilic ESG nanoballs were synthesized by introducing a cholesterol group to enzymatically synthesized glycogen (CHESG). CHESG assembled into a structure containing a few molecules to form cluster nanogels (approximately 35 nm in diameter) in water. The cluster nanogels were dissociated by the addition of cyclodextrin (CD) to form a supramolecular CHESG-CD nanocomplex due to complexation with the cholesterol group and CD. The CHESG nanogel showed high capacity for complexation with proteins, and the CHESG-CD nanocomplex showed high chaperone-like activity for thermal stabilization of enzymes. CHESG has great potential to become a new building block for nanogel biomedical engineering and to act as an artificial chaperone for protein engineering.

Three novel NY-ESO-1 epitopes bound to DRB1*0803, DQB1*0401 and DRB1*0901 recognized by CD4 T cells from CHP-NY-ESO-1-vaccinated patients

Three novel NY-ESO-1 CD4 T cell epitopes were identified using PBMC obtained from patients who were vaccinated with a complex of cholesterol-bearing hydrophobized pullulan (CHP) and NY-ESO-1 protein (CHP-NY-ESO-1). The restriction molecules were determined by antibody blocking and using various EBV-B cells with different HLA alleles as APC to present peptides to CD4 T cells. The minimal epitope peptides were determined using various N- and C-termini truncated peptides deduced from 18-mer overlapping peptides originally identified for recognition. Those epitopes were DRB1*0901-restricted NY-ESO-1 87-100, DQB1*0401-restricted NY-ESO-1 95-107 and DRB1*0803-restricted NY-ESO-1 124-134. CD4 T cells used to determine those epitope peptides recognized EBV-B cells or DC that were treated with recombinant NY-ESO-1 protein or NY-ESO-1-expressing tumor cell lysate, suggesting that the epitope peptides are naturally processed. These CD4 T cells showed a cytokine profile with Th1 characteristics. Furthermore, NY-ESO-1 87-100 peptide/HLA-DRB1*0901 tetramer staining was observed. Multiple Th1-type CD4 T cell responses are beneficial for inducing effective anti-tumor responses after NY-ESO-1 protein vaccination.

CTLA-4 blockade enhances polyfunctional NY-ESO-1 specific T cell responses in metastatic melanoma patients with clinical benefit

Blockade of inhibitory signals mediated by cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) has been shown to enhance T cell responses and induce durable clinical responses in patients with metastatic melanoma. The functional impact of anti-CTLA-4 therapy on human immune responses is still unclear. To explore this, we analyzed immune-related adverse events and immune responses in metastatic melanoma patients treated with ipilimumab, a fully human anti-CTLA-4 monoclonal antibody. Fifteen patients were selected on the basis of availability of suitable specimens for immunologic monitoring, and eight of these showed evidence of clinical benefit. Five of the eight patients with evidence of clinical benefit had NY-ESO-1 antibody, whereas none of seven clinical non-responders was seropositive for NY-ESO-1. All five NY-ESO-1 seropositive patients had clearly detectable CD4(+) and CD8(+) T cells against NY-ESO-1 following treatment with ipilimumab. One NY-ESO-1 seronegative clinical responder also had a NY-ESO-1 CD4(+) and CD8(+) T cell response, possibly related to prior vaccination with NY-ESO-1. Among five clinical non-responders analyzed, only one had a NY-ESO-1 CD4(+) T cell response and this patient did not have detectable anti-NY-ESO-1 antibody. Overall, NY-ESO-1-specific T cell responses increased in frequency and functionality during anti-CTLA-4 treatment, revealing a polyfunctional response pattern of IFN-gamma, MIP-1beta and TNF-alpha. We therefore suggest that CTLA-4 blockade enhanced NY-ESO-1 antigen-specific B cell and T cell immune responses in patients with durable objective clinical responses and stable disease. These data provide an immunologic rationale for the efficacy of anti-CTLA-4 therapy and call for immunotherapeutic designs that combine NY-ESO-1 vaccination with CTLA-4 blockade.

Analysis of peripheral and local anti-tumor immune response in esophageal cancer patients after NY-ESO-1 protein vaccination

NY-ESO-1 antigen is a prototype of a class of cancer/testis antigens. We carried out a clinical trial using NY-ESO-1 whole protein as a cancer vaccine for 13 advanced cancer patients. We have recently reported that vaccine elicited humoral and cellular immune responses in 9 cancer patients including 4 esophageal cancer patients, and clinical responses were also observed in 4 of 5 evaluable patients. In this study, we analyzed the responses in 8 esophageal cancer patients including 4 newly enrolled patients. Patients were injected subcutaneously at biweekly intervals with NY-ESO-1 recombinant protein formulated with cholesterol-bearing hydrophobized pullulan. Induction of antibody, and CD4 and CD8 T-cell responses were observed in 7, 7 and 6 patients, respectively, out of 8 patients. 1 PR, 2 SD and 2 mixed clinical responses were observed in 6 evaluable patients. No significant adverse events were observed. Furthermore, we analyzed NY-ESO-1 and MHC class I expression and the infiltration of immune cells into tumor samples obtained before and after vaccination from 4 patients by immunohistochemistry. The results showed 2 patients with disappearance of CD4 and CD8 T-cell infiltration, 1 patient with increase in the number of CD68(+) macrophages and 1 patient with tumor antigen loss in the progressive tumors following vaccinations. The induction of NY-ESO-1 immunity and some preferable clinical outcomes were observed in esophageal cancer patients by vaccination with NY-ESO-1. However, the tumors grew eventually by various mechanisms after vaccination.