T cells take aim at cancer

IL-27 in combination with anti-PD-1 can be anti-cancer or pro-cancer

Interleukin-27 (IL-27) is known to play opposing roles in immunology. The present paper considers, specifically, the role IL-27 plays in cancer immunotherapy when combined with immune checkpoint inhibitor anti-PD-1. We first develop a mathematical model for this combination therapy, by a system of Partial Differential Equations, and show agreement with experimental results in mice injected with melanoma cells. We then proceed to simulate tumor volume with IL-27 injection at a variable dose F and anti-PD-1 at a variable dose g. We show that in some range of "small" values of g, as f increases tumor volume decreases as long as fFc(g), where Fc(g) is a monotone increasing function of g. This demonstrates that IL-27 can be both anti-cancer and pro-cancer, depending on the ranges of both anti-PD-1 and IL-27.

Interfacial Polymerization Produced Magnetic Particles with Nano-Filopodia for Highly Accurate Liquid Biopsy in the PSA Gray Zone

Magnetic particles are leading separation materials for biological purification and detection. Existing magnetic particles, which almost rely on molecule-level interactions, however, often encounter bottlenecks in highly efficient cell-level separation due to the underestimate of surface structure effects. Here, immune cell-inspired magnetic particles with nano-filopodia (NFMPs) produced by interfacial polymerization for highly efficient capture of circulating tumor cells (CTCs) and further accurate clinical diagnosis of prostate cancer are reported . The unprecedented construction of nano-filopodia on polymer-based magnetic particles is achieved by introducing electrostatic interactions in emulsion interfacial polymerization. Due to the unique nano-filopodia, the NFMPs allow remarkably enhanced CTCs capture efficiency (86.5% ± 2.8%) compared with smooth magnetic particles (SMPs, 35.7% ± 5.7%). Under the assistance of machine learning by combining with prostate-specific antigen (PSA) and free to total PSA (F/T-PSA), the NFMPs strategy demonstrates high sensitivity (100%), high specificity (93.3%), and a high area under the curve (AUC) value (98.1%) for clinical diagnosis of prostate cancer in the PSA gray zone. The NFMPs are anticipated as an efficient platform for CTCs-based liquid biopsy toward early cancer diagnosis and prognosis evaluation.

Improved Mesenchymal Stem Cell Proliferation, Differentiation, Epithelial Transition, and Restrained Senescence on Hierarchically Patterned Porous Honey Silk Fibroin Scaffolds

We report a significant improvement of adipose-derived mesenchymal stem cells' (ADMSCs) biocompatibility and proliferation on hierarchically patterned porous honey-incorporated silk fibroin scaffolds fabricated using a combination of soft lithography and freeze-drying techniques. Parametric variations show enhanced surface roughness, swelling, and degradation rate with good pore interconnectivity, porosity, and mechanical strength for soft-lithographically fabricated biomimetic microdome arrays on the 2% honey silk fibroin scaffold (PHSF2) as compared to its other variants, which eventually made PHSF2 more comparable to the native environment required for stem cell adhesion and proliferation. PHSF2 also exhibits sustained honey release with remarkable antibacterial efficacy against methicillin-resistant Staphylococcus aureus (MRSA). Honey incorporation (biochemical cue) influences microdome structural features, that is, biophysical cues (height, width, and periodicity), which further allows ADMSCs pseudopods (filopodia) to grasp the microdomes for efficient cell-cell communication and cell-matrix interaction and regulates ADMSCs behavior by altering their cytoskeletal rearrangement and thereby increases the cellular spreading area and cell sheet formation. The synergistic effect of biochemical (honey) and biophysical (patterns) cues on ADMSCs studied by the nitro blue tetrazolium assay and DCFDA fluorescence spectroscopy reveals limited free radical generation within cells. Molecular expression studies show a decrease in p53 and p21 expressions validating ADMSCs senescence inhibition, which is further correlated with a decrease in cellular senescence-associated β galactosidase activity. We also show that an increase in CDH1 and CK19 molecular expressions along with an increase in SOX9, RUNX2, and PPARγ molecular expressions supported by PHSF2 justify the substrate's efficacy of underpinning mesenchymal to epithelial transition and multilineage trans-differentiation. This work highlights the fabrication of a naturally healing nutraceutical (honey)-embedded patterned porous stand-alone tool with the potential to be used as smart stem cells delivering regenerative healing implant.

Parameter estimation and treatment optimization in a stochastic model for immunotherapy of cancer

Adoptive Cell Transfer therapy of cancer is currently in full development and mathematical modeling is playing a critical role in this area. We study a stochastic model developed by Baar et al. (2015) for modeling immunotherapy against melanoma skin cancer. First, we estimate the parameters of the deterministic limit of the model based on biological data of tumor growth in mice. A Nonlinear Mixed Effects Model is estimated by the Stochastic Approximation Expectation Maximization algorithm. With the estimated parameters, we return to the stochastic model and calculate the probability of complete T cells exhaustion. We show that for some relevant parameter values, an early relapse is due to stochastic fluctuations (complete T cells exhaustion) with a non negligible probability. Then, focusing on the relapse related to the T cell exhaustion, we propose to optimize the treatment plan (treatment doses and restimulation times) by minimizing the T cell exhaustion probability in the parameter estimation ranges.

Prediction of cancer neoepitopes needs new rules

Tumors are immunogenic and the non-synonymous point mutations harbored by tumors are a source of their immunogenicity. Immunologists have long been enamored by the idea of synthetic peptides corresponding to mutated epitopes (neoepitopes) as specific "vaccines" against tumors presenting those neoepitopes in context of MHC I. Tumors may harbor hundreds of point mutations and it would require effective prediction algorithms to identify candidate neoepitopes capable of eliciting potent tumor-specific CD8⁺ T cell responses. Our current understanding of MHC I-restricted epitopes come from the observance of CD8⁺ T cell responses against viral (vaccinia, lymphocytic choriomeningitis etc.) and model (chicken ovalbumin, hen egg lysozyme etc.) antigens. Measurable CD8⁺ T cell responses elicited by model or viral antigens are always directed against epitopes possessing strong binding affinity for the restricting MHC I alleles. Immense collective effort to develop methodologies combining genomic sequencing, bioinformatics and traditional immunological techniques to identify neoepitopes with strong binding affinity to MHC I has only yielded inaccurate prediction algorithms. Additionally, new evidence has emerged suggesting that neoepitopes, which unlike the epitopes of viral or model antigens have closely resembling wild-type counterparts, may not necessarily demonstrate strong affinity to MHC I. Our bearing need recalibration.

Harnessing T-cell activity against prostate cancer: A therapeutic microparticulate oral cancer vaccine

Prostate Cancer specific immunotherapy in combination with immune stimulating adjuvants may serve as a viable strategy for facilitating tumor regression and preventing recurrence. In this study, an oral microparticulate vaccine encapsulating tumor associated antigens (TAA) extracted from a murine prostate cancer cell line, TRAMP-C2, was formulated with the help of a spray dryer. Microparticles were characterized in vitro to determine their physicochemical properties and antigenicity. Formulated microparticles had an average size of 4.92 ± 0.5 μm with a zeta potential of 7.92 ± 1.2 mV. In order to test our formulation for its ability to demonstrate adequate antigen presentation and co-stimulation, microparticles were tested in vitro on murine dendritic cells. In vitro biological characterization demonstrated the activation of specific immune system markers such as CD80/86, CD40, MHC-I and MHC-II. Following in vitro characterization, in vivo anti-tumor efficacy of the oral microparticulate vaccine was evaluated in C57BL/6 male mice. Combination therapy of vaccine microparticles with cyclophosphamide and granulocyte macrophage-colony stimulating factor (GM-CSF) demonstrated a five-fold reduction in tumor volume as compared to non-vaccinated mice. At the cellular level, cyclophosphamide and GM-CSF augmented the vaccine response as indicated by the reduced tumor volume and significant elevation of cytotoxic T-cell (CTL) CD8+ and (T-helper) CD4+ T-cells compared to mice receiving vaccine microparticles alone. Furthermore, our studies indicate a significant reduction in T-regulatory cells (T-regs) in mice receiving vaccine along with GM-CSF and cyclophosphamide, one of the immune escape mechanisms linked to tumor growth and progression. Thus, oral microparticulate vaccines have the potential to trigger a robust anti-tumor cellular response, and in combination with clinically relevant agents, significantly resist tumor growth and progression.

Bioinspired Hierarchically Structured Surfaces for Efficient Capture and Release of Circulating Tumor Cells

The development of novel bioinspired surfaces with hierarchical micro- and nanoscale topographic structures for efficient capture and release of circulating tumor cells (CTCs) is reported. The capture of CTCs, facilitated by surface-immobilized epithelial cell adhesion molecule antibodies (anti-EpCAM), was shown to be significantly enhanced in novel three-dimensional hierarchically structured surfaces that were fabricated by replicating the natural micro- and nanostructures of rose petals. Under static conditions, these hierarchical capture substrates exhibited up to 6 times higher cell capture ability at concentrations of 100 cells mL^-1 in contrast to flat anti-EpCAM-functionalized polydimethylsiloxane (PDMS) surfaces. As indicated by scanning electron microscopy (SEM) and immunofluorescent images, this enhancement can be in large part attributed to the topographical interaction between nanoscale cell surface components and nanostructures on the substrate. Similarly, the increased surface area affords a higher nominal coverage of anti-EpCAM, which increases the number of available binding sites for cell capture. By treating the substrates with the biocompatible reductant glutathione (GSH), up to 85% of the captured cells were released, which displayed over 98% cell viability after culturing on tissue culture polystyrene (TCP) for 24 h. Therefore, these bioinspired hierarchically structured and functionalized substrates can be successfully applied to capture CTCs, as well as release CTCs for subsequent analysis. These findings provide new prospects for designing cell-material interfaces for advanced cell-based biomedical studies in the future.

Cell-inspired biointerfaces constructed from patterned smart hydrogels for immunoassays in whole blood

Inspired by stem-cell microstructure, hierarchical biointerfaces based on patterned smart hydrogels are generated for successful immunoassays in whole blood. And their sensitivity is controllable by temperature.

IL-10: Expanding the Immune Oncology Horizon

Recent advances in immunoncology have dramatically changed the treatment options available to cancer patients. However, the fundamental challenges with this therapeutic modality are not new and still persist with the current wave of immunoncology compounds. These challenges are centered on the activation and expansion, induction of intratumoral infiltration and persistence of highly activated, cytotoxic, tumor antigen specific CD8+ T cells. We have investigated the anti-tumor mechanism of action of pegylated recombinant interleukin-10, (PEG-rIL-10) both pre-clinically with murine (PEG-rMuIL-10) and now clinically (AM0010) with human pegylated interleukin-10. The preponderance of data suggest that IL-10's engagement of its receptor on CD8+ T cells enhances their activation status leading to antigen specific expansion. Quantitation of CD8+ T cell tumor infiltration reveals that treatment of both humans and mice with pegylated rIL-10 results in 3-4 fold increases of intratumoral, cytotoxic, CD8+ T cells. In addition, mice cured of their tumors with PEG-rMuIL-10 exhibit long term immunological protection from tumor re-challenge and long term treatment of cancer patients with AM0010 results in the persistence of highly activated CD8+ T cells. Cumulatively, these data suggest the IL-10 represents an emerging therapeutic that specifically addresses the fundamental challenges of the current wave of immunoncology assets.

RETRACTED: T cell metabolism. The protein LEM promotes CD8⁺ T cell immunity through effects on mitochondrial respiration

Protective CD8(+) T cell-mediated immunity requires a massive expansion in cell number and the development of long-lived memory cells. Using forward genetics in mice, we identified an orphan protein named lymphocyte expansion molecule (LEM) that promoted antigen-dependent CD8(+) T cell proliferation, effector function, and memory cell generation in response to infection with lymphocytic choriomeningitis virus. Generation of LEM-deficient mice confirmed these results. Through interaction with CR6 interacting factor (CRIF1), LEM controlled the levels of oxidative phosphorylation (OXPHOS) complexes and respiration, resulting in the production of pro-proliferative mitochondrial reactive oxygen species (mROS). LEM provides a link between immune activation and the expansion of protective CD8(+) T cells driven by OXPHOS and represents a pathway for the restoration of long-term protective immunity based on metabolically modified cytotoxic CD8(+) T cells.

Impact of the immune system and immunotherapy in colorectal cancer

The development of cancer is a multi-step process involving the gradual loss of regulation over the growth and functional capabilities of normal cells. Much research has been focused on the numerous cell intrinsic factors that govern this process; however, recent attention has turned to understanding the cell extrinsic factors in the tumor microenvironment that appear equally critical to the progression and treatment of cancer. One critical component of the tumor microenvironment is the immune system and it has become increasingly evident that the immune system plays an integral role in preventing and promoting the development of cancer. Understanding the immune cell types and pathways involved in this process has enabled the development of novel biomarkers for prognosis and accelerated the development of immune-based therapeutics, both of which have the potential to forever change the treatment paradigms for colorectal cancer (CRC). In this review, we discuss the impact of the immune system on the initiation, progression and treatment of cancer, specifically focusing on CRC.

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

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

Spontaneous remission of acute myeloid leukemia

Spontaneous remission (SR) of acute myeloid leukemia (AML) is rare. We collected all 46 reported cases of AML with SR. Fever occurred in 91.3% of cases before remission, which was largely due to pneumonia (54.5%) and bacteremia (24.2%). Pneumonia and bacteremia were significantly more common among those who achieved complete remission (CR) compared to those who achieved only a partial remission (p = 0.032). Although 88.6% of remissions were CR, the median duration of remission was only 5 months. Eight cases did not relapse during the follow-up period. The mechanism of SR in AML likely involves the stimulatory effect of systemic febrile infection on the immune system. Immediate treatment of infections and fever may contribute to the rarity of SR in AML. The results of this review improve our understanding of the important role of the immune system in countermanding AML and may provide new ideas for immunotherapy.

Pain palliative therapy in women with breast cancer osseous metastatic disease and the role of specific serum cytokines as prognostic factors

PURPOSE

To evaluate the efficacy of radionuclide palliative therapy (RPT) in women suffering from painful metastatic bone disease (MBD) due to breast cancer (BrCa), and to investigate the possible relationship between the RPT efficacy and cytokines levels.

METHODS

Sixty-three BrCa women patients with MBD enrolled in a prospective, nonrandomized study. Thirty were treated with Rhenium-186-hydroxyethylidenediphosphonic acid ((186)Re-HEDP), 21 with Strontium-89-Chloride ((89)Sr-Cl2), and 12 with Samarium-153-thylenediaminetetramethylenephosphonic acid ((153)Sm-EDTMP). Blood samples were collected pre- and post-therapy to assess the interleukin (IL)-2, IL-6 and tumor necrosis factor (TNF)-a titers. The palliative effect of the treatment was evaluated using a modified Wisconsin test.

RESULTS

All three radiopharmaceuticals were equally effective in pain relief. Pain palliation was complete in 52% of patients, partial in 31%, and absent in 16%. Responders to therapy had higher IL-2 and lower IL-6/TNF-a concentrations, compared with nonresponders, even though statistically significant difference in cytokines levels between responders and nonresponders before treatment was noted only for IL-6.

CONCLUSION

All used radiopharmaceuticals had the same therapeutic effect. Pretherapy low titers of IL-6 levels seems to have a favorable prognostic value for the therapeutic outcome, while IL-2 and TNF-a alterations pre- and post-therapy can only serve as markers of a better RPT response.

Three-dimensional nano-biointerface as a new platform for guiding cell fate

The recent explorations of three-dimensional nano-biointerfaces for cell-related fundamental biological studies and advanced biomedical applications are reviewed.

The role of inflammation in prostate cancer

In the United States and in "Westernized" countries, the prevalence of both prostate cancer and prostate inflammation is very high, indicating that the two pathologies could be causally related. Indeed, chronic inflammation is now regarded as an "enabling" characteristic of human cancer. Prostate cancer incidence is thought to be mediated in part by genetics, but also by environmental exposures, including the same exposures that may contribute to the development of prostatic inflammation. As our understanding of the role of inflammation in cancer deepens, it is increasingly apparent that "inflammation" as a whole is a complex entity that does not always play a negative role in cancer etiology. In fact, inflammation can play potentially dichotomous (both pro and antitumorigenic) roles depending on the nature and the cellular makeup of the immune response. This chapter will focus on reviewing the current state of knowledge on the role of innate and adaptive immune cells within the prostate tumor microenvironment and their seemingly complex role in prostate cancer in preventing versus promoting initiation and progression of the disease.

Toxicological impact of inhaled electric mosquito-repellent liquid on the rat: a hematological, cytokine indications, oxidative stress and tumor markers

CONTEXT

High malaria burden has led to the increased use of insecticides in the tropics and subtropics. This study thus aimed at assessing the hematological effects alteration of pyrethroid insecticide exposure using the experimental animal model.

OBJECTIVE

A commonly available Electric Mosquito-Repellent Liquid pyrethroid insecticide containing prallethrin 1.6% w/w is widely used for mosquito control in Saudi Arabia. The immunotoxic effects after inhalation exposures to the preparation for a continuous period of 24, 48, and 72 h were investigated in rats.

METHODS AND MATERIALS

Rats were exposed to prallethrin 1.6% w/w by inhalation for 72 consecutive hours. Total blood count, blood indices of creatine kinase (CK), gamma-glutamyltranspeptidase (γ-GT), superoxide dismutase (SOD), nitric oxide (NO), malondialdehyde (MDA), interleukin (IL)-2, tumor necrosis factors (TNF)α, alpha-fetoprotein (AFP), carbohydrate antigen (CA) 19.9 and carcinoembrionic antigen (CEA) were assayed.

RESULTS

The administration of prallethrin 1.6% w/w created significant increased changes in the levels of total WBC, lymphocytes, RBC, hemoglobin, packed cell volume, platelets, mean corpuscular volume, and mean corpuscular hemoglobin in rats after 24, 48, and 72 h of continuous inhalation; however, there was a significant reduction in neutrophils at transient reduction in the monocytes after 24 and 48 h to return to normal after 72 h. Significant increases in the levels of CK, γ-GT, SOD, NO, MDA, AFP, IL-2, and TNFα were recorded. CA and CEA did not exhibit any change.

CONCLUSIONS

Continuous inhalation to prallethrin 1.6% insecticides poses toxicity on hematological variables. It is also concluded that pyrethroid group of insecticide may cause hematological, biochemical, cytokine disturbances and possible mutagenic damage to the tissues.

Low-affinity T cells are programmed to maintain normal primary responses but are impaired in their recall to low-affinity ligands

T cell responses to low-affinity T cell receptor (TCR) ligands occur in the context of infection, tumors, and autoimmunity despite diminished TCR signal strength. The processes that enable such responses remain unclear. We show that distinct mechanisms drive effector/memory development in high- and low-affinity T cells. Low-affinity cells preferentially differentiate into memory precursors of a central memory phenotype that are interleukin (IL)-12R(lo), IL-7R(hi), and Eomes(hi). Strikingly, in contrast to naive cells, low-affinity memory cells were impaired in the response to low- but not high-affinity ligands, indicating that low-affinity cells are programmed to generate diverse immune responses while avoiding autoreactivity. Affinity and antigen dose directly correlated with IL-12R signal input and T-bet but not with Eomes expression because low- affinity signals were more potent inducers of Eomes at a high antigen dose. Our studies explain how weak antigenic signals induce complete primary immune responses and provide a framework for therapeutic intervention.

Can immuno-oncology offer a truly pan-tumour approach to therapy?

Increased understanding of cellular and molecular tumour immunology over the past two decades has enabled the identification of new and innovative ways to manipulate the immune response to cancer, with recent phase III trials in patients with metastatic melanoma and hormone-resistant prostate cancer providing proof-of-principle that immunotherapies can improve survival. Based on these successes, many new immunotherapies are being developed, including vaccines and other agents that prime or boost the immune system, T-cell modulatory agents, agents that enhance innate immunity and agents designed to inhibit immunosuppression within the tumour microenvironment. Current experience suggests that immunotherapies are a promising foundation to build treatment regimens for a variety of tumour types. Because many approaches target the immune system and not the cancer, immunotherapies are being evaluated in almost every tumour type, including those that were not previously considered likely to respond to immune manipulation. Immunotherapies also have potential for durable and adaptable cancer control at different stages of disease, including those with early-stage disease and low tumour burdens. To maximise benefits, however, it is likely that combination regimens with conventional cancer treatments or other immunotherapies will be necessary. In addition, the identification of biomarkers will allow further optimisation from a mechanistic and a patient selection perspective. Further advances in research will necessitate multidisciplinary collaboration among physicians, basic and translational researchers and the pharmaceutical industry to ensure that immuno-oncology becomes a cornerstone element in the development of cancer therapy.

Combination immunotherapy approaches

Combination immunotherapy approaches involving radiation, chemotherapy, androgen manipulation and T-cell modulation have been studied extensively in animal models, setting the stage for clinical trials. Radiation therapy, in particular, is an interesting modality in this regard, leading to synergistic efficacy when used in combination with immunotherapies in several models. Chemotherapy, the foundation of treatment of metastatic disease, may also augment the immune response to cancer; however, the potential immunosuppressive effects of chemotherapy render issues of dosing and timing critical. Perhaps, the most exciting combinatorial approach may be the co-administration of multiple immunological treatments. For example, in preclinical investigations, combined blockade of programmed death-1 (PD1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), which have key roles in the negative regulation of T-cell activation, has been shown to enhance antitumour immune responses compared with either agent alone. Taken together, the available data provide a strong rationale for initiating combination clinical trials, but lend a note of caution in that issues of dosing and timing likely require careful exploration in a phase II setting.

Mathematical modeling of the immune system recognition to mammary carcinoma antigen

The definition of artificial immunity, realized through vaccinations, is nowadays a practice widely developed in order to eliminate cancer disease. The present paper deals with an improved version of a mathematical model recently analyzed and related to the competition between immune system cells and mammary carcinoma cells under the action of a vaccine (Triplex). The model describes in detail both the humoral and cellular response of the immune system to the tumor associate antigen and the recognition process between B cells, T cells and antigen presenting cells. The control of the tumor cells growth occurs through the definition of different vaccine protocols. The performed numerical simulations of the model are in agreement with in vivo experiments on transgenic mice.

A mathematical model of immune-system-melanoma competition

We present a mathematical model developed to reproduce the immune response entitled with the combined administration of activated OT1 cytotoxic T lymphocytes (CTLs) and Anti-CD137 monoclonal antibodies. The treatment is directed against melanoma in B16 OVA mouse models exposed to a specific immunotherapy strategy. We model two compartments: the injection point compartment where the treatment is administered and the skin compartment where melanoma tumor cells proliferate. To model the migration of OT1 CTLs and antibodies from the injection to the skin compartment, we use delay differential equations (DDEs). The outcomes of the mathematical model are in good agreement with the in vivo results. Moreover, sensitivity analysis of the mathematical model underlines the key role of OT1 CTLs and suggests that a possible reduction of the number of injected antibodies should not affect substantially the treatment efficacy.

Anticancer and immunostimulatory activity by conjugate of paclitaxel and non-toxic derivative of LPS for combined chemo-immunotherapy

PURPOSE

Cancer is a multifactorial syndrome; hence, multidimensional therapy with a chemo-immunotherapeutic conjugate could be more effective in curing the disease.

METHODS

We used SP-LPS, a bio-polymer having potent immunostimulatory activity, for conjugation with paclitaxel to make a chemo-immunotherapeutic conjugate. Its physicochemical characterization was done by HPLC, NMR and IR spectra. Stability was measured at different pH, temperature and in tissue homogenates. Chemotherapeutic and immunostimulatory activity was evaluated in vitro and also in tumor microenvironment.

RESULTS

The conjugate self assembled into nanoparticulate structure, probably due to micelle formation. Stability was pH and temperature dependent. The conjugate exhibited chemotherapeutic and immunotherapeutic activity in vitro. In vivo antitumor activity was significantly higher and a higher percentage of activated immune cells were found in the tumor microenvironment of the conjugate-treated mice as compared to Taxol®-treated group.

CONCLUSIONS

This conjugate is a potential chemo-immunotherapeutic compound for the treatment of cancer with advantages over present day chemotherapy with Taxol in terms of higher anticancer activity, less toxicity and ease of delivery.

Tumor-associated-antigens or osteosarcoma cell line lysates: two efficient methods for in vitro generation of CTLs with special regard to MHC-I restriction

The expression of tumor associated antigens (TAA) in osteosarcoma cell lines allowed us to design an in vitro model for the generation of TAA-specific CTLs. Since the MHC-I-restriction of these peptides represents the major obstacle to clinical applications, we studied a second method for the generation of CTLs starting from osteosarcoma cell line lysates and PBMCs of HLA-I compatible healthy donors. TAA-specific CTLs showed high and homogeneous cytotoxic response against each peptide; high levels of IFN-γ were released by osteosarcoma cell line lysate specific-CTLs in response to the osteosarcoma cell line they were activated for. The MHC-I dependent osteosarcoma cell line lysate-specific CTLs activity was proved by the indifference against the HLA-I-negative erytroleukaemia cell line K562 and by the absence of IFN-γ production with the addition of HLA-class I blocking antibodies. These two methods may be considered the model for the autologous setting in the context of immunotherapeutic approaches for osteosarcoma patients.

Trends in cancer immunotherapy

Modulation of the immune system for therapeutic ends has a long history, stretching back to Edward Jenner's use of cowpox to induce immunity to smallpox in 1796. Since then, immunotherapy, in the form of prophylactic and therapeutic vaccines, has enabled doctors to treat and prevent a variety of infectious diseases, including cholera, poliomyelitis, diphtheria, measles and mumps. Immunotherapy is now increasingly being applied to oncology. Cancer immunotherapy attempts to harness the power and specificity of the immune system for the treatment of malignancy. Although cancer cells are less immunogenic than pathogens, the immune system is capable of recognizing and eliminating tumor cells. However, tumors frequently interfere with the development and function of immune responses. Thus, the challenge for cancer immunotherapy is to apply advances in cellular and molecular immunology and develop strategies that effectively and safely augment antitumor responses.

Poor prognosis osteosarcoma: new therapeutic approach

Over the past 30 years, a significant improvement in the prognosis of localized osteosarcoma of the extremities has been observed. Despite these results, approximately 30-40% of patients will relapse, mostly within the first 3 years from diagnosis. The prognosis of patients with recurrent disease or metastases at diagnosis is poor. To improve the survival in this patient population, several attempts have been made. An increased dose intensity of chemotherapy induces short lasting remission but does not increase the survival. In the era of targeted therapy, few drugs have been tested with dismal results. The use of biological agents endowed with immunomodulant activity (that is IL-2) or reduced-intensity allogeneic hemopoietic SCT has produced intriguing results that need further confirmation. In this context, an ongoing study explores the antitumor activity of specific T-cytotoxic lymphocytes.

Combination of Transient Lymphodepletion With Busulfan and Fludarabine and Peptide Vaccination in a Phase I Clinical Trial for Patients With Advanced Melanoma

Taking advantage of homeostatic mechanisms to boost tumor-specific cellular immunity is raising increasing interest in the development of therapeutic strategies in the treatment of melanoma. Here, we have explored the potential of combining homeostatic proliferation, after transient immunosuppression, and antigenic stimulation of Melan-A/Mart-1 specific CD8 T-cells. In an effort to develop protocols that could be readily applicable to the clinic, we have designed a phase I clinical trial, involving lymphodepleting chemotherapy with Busulfan and Fludarabine, reinfusion of Melan-A specific CD8 T-cell containing peripheral blood mononuclear cells (exempt of growth factors), and Melan-A peptide vaccination. Six patients with advanced melanoma were enrolled in this outpatient regimen that demonstrated good feasibility combined with low toxicity. Consistent depletion of lymphocytes with persistent increased CD4/CD8 ratios was induced, although the proportion of circulating CD4 regulatory T-cells remained mostly unchanged. The study of the immune reconstitution period showed a steady recovery of whole T-cell numbers overtime. However, expansion of Melan-A specific CD8 T-cells, as measured in peripheral blood, was mostly inconsistent, accompanied with marginal phenotypic changes, despite vaccination with Melan-A/Mart-1 peptide. On the clinical level, 1 patient presented a partial but objective antitumor response following the beginning of the protocol, even though a direct effect of Busulfan/Fludarabine cannot be completely ruled out. Overall, these data provide further ground for the development of immunotherapeutic approaches to be both effective against melanoma and applicable in clinic.

A2A adenosine receptor protects tumors from antitumor T cells

The A2A adenosine receptor (A2AR) has been shown to be a critical and nonredundant negative regulator of immune cells in protecting normal tissues from inflammatory damage. We hypothesized that A2AR also protects cancerous tissues by inhibiting incoming antitumor T lymphocytes. Here we confirm this hypothesis by showing that genetic deletion of A2AR in the host resulted in rejection of established immunogenic tumors in approximately 60% of A2AR-deficient mice with no rejection observed in control WT mice. The use of antagonists, including caffeine, or targeting the A2 receptors by siRNA pretreatment of T cells improved the inhibition of tumor growth, destruction of metastases, and prevention of neovascularization by antitumor T cells. The data suggest that effects of A2AR are T cell autonomous. The inhibition of antitumor T cells via their A2AR in the adenosine-rich tumor microenvironment may explain the paradoxical coexistence of tumors and antitumor immune cells in some cancer patients (the "Hellstrom paradox"). We propose to target the hypoxia-->adenosine-->A2AR pathway as a cancer immunotherapy strategy to prevent the inhibition of antitumor T cells in the tumor microenvironment. The same strategy may prevent the premature termination of immune response and improve the vaccine-induced development of antitumor and antiviral T cells. The observations of autoimmunity during melanoma rejection in A2AR-deficient mice suggest that A2AR in T cells is also important in preventing autoimmunity. Thus, although using the hypoxia-->adenosine-->A2AR pathway inhibitors may improve antitumor immunity, the recruitment of this pathway by selective drugs is expected to attenuate the autoimmune tissue damage.

The effects of gp100 and tyrosinase peptide vaccinations on nevi in melanoma patients

BACKGROUND

A new approach to prevent disease recurrence in high-risk melanoma patients involves immunization with gp100 and tyrosinase peptides. This is the first study to examine the effects of such treatments on nevi.

DESIGN

We studied biopsies of 'clinically atypical' nevi from 10 patients before and after peptide vaccination. All had a cutaneous melanoma measuring at least 1.5 mm in depth, satellite metastases, or at least one positive lymph node. We performed immunohistochemical stains for CD3, CD4, CD8, MHC-I, MHC-II, CD1a, HMB-45, MART-1, tyrosinase, bcl-2, p53, and Ki-67 (mib-1).

RESULTS

Immunohistochemistry showed no differences in staining due to vaccination in either the immunologic or melanocytic markers. However, there was a significant increase in both p53 and bcl-2 staining, and a trend toward decreased Ki-67 staining, in the nevi post-treatment.

DISCUSSION

The primary goal of peptide vaccinations with gp100 and tyrosinase is to activate melanoma-specific T cells in order to prevent melanoma recurrence. Nevi were studied in order to assess the effects on benign melanocytes. No significant changes in lymphocytes, langerhans cells, expression of MHC antigens, or melanocytic markers were found. The increase in p53 and bcl-2 raises the possibility that vaccination with melanocytic antigens stimulates a response in benign melanocytes.

T cell-mediated immunotherapy of metastases: state of the art in 2005

Advances in cellular and molecular immunology have led to the development of strategies for effective augmentation of antitumour immune responses in cancer patients. This review focuses on the manipulation of T cell immunity either by active specific immunotherapy (ASI) using tumour vaccines, or by adoptive immunotherapy (ADI) with immune T cells. Such therapies offer exquisite specificity of tumour recognition based on the ability of the T cell to distinguish single amino acid differences in any protein from any compartment of the tumour cell. Examples are presented of clinical survival benefits for cancer patients by postoperative ASI with a modified autologous tumour vaccine of high quality. Furthermore, clinical studies employing ADI with T cells activated and expanded ex vivo have demonstrated 'proof of principle' that tumour-specific T cells are capable of mediating anticancer activity in vivo, as measured by regression of metastatic tumours. Translation of these findings into a standardised immunotherapy is, however, not easy and will require coordination and cooperation among academic, private and federal sectors.

Impact of comorbid anxiety and depression on quality of life and cellular immunity changes in patients with digestive tract cancers

AIM: A study was performed to investigate the impact of comorbid anxiety and depression (CAD) on quality of life (QOL) and cellular immunity changes in patients with digestive tract cancers.

METHODS: One hundred and fifty-six cases of both sexes with cancers of the digestive tract admitted between March 2001 and February 2004 in the Department of Medical Oncology, First Affiliated Hospital of Xi’an Jiaotong University were randomly enrolled in the study. Depressive and anxiety disorder diagnoses were assessed by using the Structured Clinical Interview for DSM-IV. All adult patients were evaluated with the Hamilton depressive scale (HAMD, the 24-item version), the Hamilton anxiety scale (HAMA, a modified 14-item version), quality of life questionnaire-core 30 (QLQ-C30), social support rating scale (SSRS), simple coping style questionnaire (SCSQ), and other questionnaires, respectively. In terms of HAMD ≥ 20 and HAMA ≥ 14, the patients were categorized, including CAD (n = 31) in group A, anxiety disorder (n = 23) in group B, depressive disorder (n = 37) in group C, and non-disorder (n = 65) in group D. Immunological parameters such as T-lymphocyte subsets and natural killer (NK) cell activities in peripheral blood were determined and compared among the four groups.

RESULTS: The incidence of CAD was 21.15% in patients with digestive tract cancers. The average scores of social support was 43.67±7.05 for 156 cases, active coping 20.34±7.33, and passive coping 9.55±5.51. Compared with group D, subjective support was enhanced slightly in group A, but social support, objective support, and utilization of support reduced, especially utilization of support with significance (6.16 vs 7.80, P<0.05); total scores of active coping decreased, while passive coping reversed; granulocytes proliferated, monocytes declined, and lymphocytes declined significantly (32.87 vs 34.00, P<0.05); moreover, the percentage of CD3, CD4, CD8 and CD56 in T lymphocyte subsets was in lower level, respectively, and CD56 showed a significant decline in group A (26.02 vs 32.20, P<0.05), however, CD4/CD8 ratio increased. Physical function, role function, fatigue, sleeplessness and constipation had significant changes among different groups by one-way ANOVA, and group A was in poor QOL. It revealed that global health-related quality of life (QL) were positively correlated with active coping and CD56; CAD was negatively correlated with QL, active coping and CD56. Furthermore, the step-wise regression analysis suggested that utilization of support, CD56, active coping, fatigue, sleeplessness and depression were significant factors contributing to QOL.

CONCLUSION: CAD, which can impair QOL and cellular immunity, occurs with a higher incidence in patients with digestive tract cancers. Hence, it is essential to improve mental health for them with specifically tailored interventions.

Fever therapy revisited

The phenomenon of spontaneous regression and remission from cancer has been observed by many physicians and was described in hundreds of publications. However, suggestive clues on cause or trigger are sparse and not substantiated by much experimental evidence. In this review, literature is surveyed and summarised and possible causes are discussed. At least in a larger fraction of cases a hefty feverish infection is linked with spontaneous regression in time and is investigated as putative trigger. Epidemiological and immunological evidence is put into perspective. An online forum to discuss the possible application of fever therapy in the future can be accessed at http://bioinfo.tg.fh-giessen.d e/fever-and-cancer.

Fate and function of anti-CD3/CD28-activated T cells following adoptive transfer: IL-2 promotes development of anti-tumor memory T cells in vivo

BACKGROUND

Adoptive immunotherapy with T cells activated through CD3 alone requires exogenous IL-2 for T-cell function and survival after transfer, but the in vivo cytokine requirement of T cells activated through CD3 and CD28 is unknown. We hypothesized that CD3/CD28-activated T cells, unlike those activated through CD3 alone, might develop into long-lived memory T cells, either with or without systemic IL-2.

METHODS

We used MHC class I-restricted TCR transgenic T cells from the OT-1 mouse, specific for the surrogate tumor Ag ovalbumin (OVA), to assess the trafficking kinetics, antigenic responsiveness and anti-tumor efficacy of dual-activated T cells in vivo as a function of IL-2 administration. At days 7, 14, and 28 after transfer, lymph node cells and splenocytes were examined for donor cell persistence and antigenic responsiveness by FACS and ELISA, respectively.

RESULTS

In IL-2-treated mice, donor CD8+ T cells persisted and developed a memory phenotype, based on CD44 and Ly6c expression at day 28, while mice given no IL-2 had fewer donor cells at all time points. OVA-specific release of IFN-gamma was higher from lymphocytes of IL-2-treated mice compared with no-IL-2 mice (P<0.02 at all time points). In mice challenged with an OVA-bearing subline of the AML leukemia model C1498, IL-2 did not confer added protection from tumor challenge at 1 or 2 weeks after adoptive transfer, but gave improved survival at 4 weeks post-transfer.

DISCUSSION

We conclude that exogenous IL-2 is not required for anti-tumor activity of CD3/CD28-activated CD8+ cells early after adoptive transfer, but promotes T-cell persistence that confers disease protection at more remote times.

Immunoprevention of Mammary Carcinoma in HER-2/neu Transgenic Mice Is IFN-γ and B Cell Dependent

A vaccine combining IL-12 and allogeneic mammary carcinoma cells expressing p185(neu) completely prevents tumor onset in HER-2/neu transgenic BALB/c mice (NeuT mice). The immune protection elicited was independent from CTL activity. We now formally prove that tumor prevention is mainly based on the production of anti-p185(neu) Abs. In the present studies, NeuT mice were crossed with knockout mice lacking IFN-gamma production (IFN-gamma(-/-)) or with B cell-deficient mice (microMT). Vaccination did not protect NeuT-IFN-gamma(-/-) mice, thus confirming a central role of IFN-gamma. The block of Ab production in NeuT-microMT mice was incomplete. About one third of NeuT-microMT mice failed to produce Abs and displayed a rapid tumor onset. By contrast, those NeuT-microMT mice that responded to the vaccine with a robust production of anti-p185(neu) Ab displayed a markedly delayed tumor onset. In these NeuT-microMT mice, the vaccine induced a lower level of IgG2a and IgG3 and a higher level of IgG2b than in NeuT mice. Moreover, NeuT-microMT mice failed to produce anti-MHC class I Abs in response to allogeneic H-2(q) molecules present in the cell vaccine. These findings show that inhibition of HER-2/neu carcinogenesis depends on cytokines and specific Abs, and that a highly effective vaccine can rescue Ab production even in B cell-deficient mice.

On the role of APC-activation for in vitro versus in vivo T cell priming

Professional antigen-presenting cells take up antigens for processing and presentation in association with MHC class I and II molecules. When APCs receive the right stimuli, they undergo a maturation process and migrate to secondary lymphoid organs to trigger T cell activation. In this study, we compared side-by-side in vivo and in vitro activation of T cells. Transgenic CD8(+) T cells specific for the p33 epitope, derived from the lymphocytic choriomeningitis virus glycoprotein, were labeled with CFSE and injected into syngeneic mice or alternatively, co-cultured in vitro with APCs. The p33 epitope was delivered as free peptide or genetically fused to virus-like particles. Whereas proliferation of specific T cells was comparable in both systems, the production of IFN-gamma and the expression of CD25 showed important differences. Induction of effector function and expression of activation markers were strongly enhanced in vitro by both the free peptide and VLPs. Surprisingly, addition of CpG-containing immune-stimulating DNA for activation of APCs dramatically increased effector T cell differentiation in vitro, whereas no enhancement could be observed in vitro. Thus, activation of professional APCs was mandatory for induction of effector CD8(+) T cell responses in vivo, while this step was largely dispensable in vitro.

Effects of depression on parameters of cell-mediated immunity in patients with digestive tract cancers

AIM: To evaluate the effects of depression on parameters of cell-mediated immunity in patients with cancers of the digestive tract.

METHODS: One hundred and eight adult patients of both sexes with cancers of the digestive tract admitted between March 2001 and February 2002 in the Department of Medical Oncology, First Affiliated Hospital of Xi’an Jiaotong University were randomly enrolled in the study. The Zung self-rating depression scale (SDS), Zung self-rating anxiety scale (SAS), numeric rating scale (NRS) and social support rating scale (SSRS) were employed to evaluate the degree of depression and their contributing factors. In terms of their SDS index scores, the patients were categorized into depression group (SDS ≥ 50) and non-depression group (SDS < 50). Immunological parameters such as T-lymphocyte subsets and natural killer (NK) cell activities in peripheral blood were determined and compared between the two groups of patients.

RESULTS: The SDS index was from 33.8 to 66.2 in the 108 cases, 50% of these patients had a SDS index more than 50. Similarly, the SAS index of all the patients ranged from 35.0 to 62.0 and 46.3% of the cases had a SAS index above 50. Cubic curve estimation showed that the depression was positively correlated with anxiety and negatively with social support. Furthermore, the depression correlated with the tumor type, which manifested in a descending order as stomach, gallbladder, pancreas, intestine, esophagus, duodenum and rectum, according to their correlativity. Step-wise regression analysis suggested that hyposexuality, dispiritment, agitation, palpitation, low CD₅₆ and anxiety were the significant factors contributing to depression. More severe anxiety (49.7 ± 7.5 vs 45.3 ± 6.9, P < 0.05), pain (6.5 ± 2.8 vs 4.6 ± 3.2, P < 0.05), poor social support (6.8 ± 2.0 vs 7.6 ± 2.1, P < 0.05), as well as decline of lymphocyte count (0.33 ± 0.09 vs 0.39 ± 0.87, P < 0.05) and CD₅₆ (0.26 ± 0.11 vs 0.29 ± 0.11, P < 0.05) were noted in the depression group compared with those of the non-depression patients. However, fewer obvious changes in CD₄/CD₈ ratio and other immunological parameters were found between the two groups.

CONCLUSION: Depression occurs with a high incidence in patients with cancers of the digestive tract, which probably is not the sole factor leading to the impairment of immunological functions in these cases. However, comprehensive measures including psychological support should be taken in order to improve the immunological function, quality of life and clinical prognosis of these patients.