Fighting cancers from within: augmenting tumor immunity with cytokine therapy

The immunomodulatory function and antitumor effect of disulfiram: paving the way for novel cancer therapeutics

More than 60 years ago, disulfiram (DSF) was employed for the management of alcohol addiction. This promising cancer therapeutic agent inhibits proliferation, migration, and invasion of malignant tumor cells. Furthermore, divalent copper ions can enhance the antitumor effects of DSF. Molecular structure, pharmacokinetics, signaling pathways, mechanisms of action and current clinical results of DSF are summarized here. Additionally, our attention is directed towards the immunomodulatory properties of DSF and we explore novel administration methods that may address the limitations associated with antitumor treatments based on DSF. Despite the promising potential of these various delivery methods for utilizing DSF as an effective anticancer agent, further investigation is essential in order to extensively evaluate the safety and efficacy of these delivery systems.

Transformation Mechanism of Rare Ginsenosides in American Ginseng by Different Processing Methods and Antitumour Effects

The mechanism by which ginsenosides from Panax quinquefolium L. transform into rare saponins by different processing methods and their antitumour effects have yet to be fully elucidated. Our study aimed to detect the effect of amino acids and processing methods on the conversion of ginsenosides in American ginseng to rare ginsenosides, using 8 monomeric ginsenosides as substrates to discuss the reaction pathway and mechanism. S180 tumour-bearing mice were established to study the antitumour effects of American ginseng total saponins (AGS-Q) or American ginseng total saponins after transformation (AGS-H) synergistic CTX. The results showed that aspartic acid was the best catalyst, and the thermal extraction method had the best effect. Under the optimal conditions, including a reaction temperature of 110°C, an aspartic acid concentration of 5%, a reaction time of 2.5 h and a liquid-solid ratio of 30 mL/g, the highest conversion of Rk₁ and Rg₅ was 6.58 ± 0.11 mg/g and 3.74 ± 0.05 mg/g, respectively. In the reaction pathway, the diol group saponins participated in the transformation process, and the triol group saponins basically did not participate in the transformation process. AGS-Q or AGS-H synergistic CTX, or AGS-H synergistic CTX/2 could significantly increase the tumour inhibition rate, spleen index and white blood cell count, had a significant upregulation effect on IL-2 and IL-10 immune cytokines; significantly restored the ratio of CD4⁺/CD8⁺; and significantly inhibited the level of CD4⁺CD25⁺. AGS-Q or AGS-H synergistic with CTX or CTX/2 can significantly upregulate the expression of Bax and cleaved-Caspase-3 and inhibit the expression of antiapoptotic protein Bcl-2. AGS synergistic CTX in the treatment of S180 tumour-bearing mice can improve the efficacy and reduce toxicity.

Opportunities in combinational chemo-immunotherapy for breast cancer using nanotechnology: an emerging landscape

INTRODUCTION

Breast carcinoma (BC) is one of the most frequent causes of cancer-related death among women, which is due to the poor response to conventional therapy. There are several complications associated with monotherapy for cancer, such as cytotoxicity to normal cells, multidrug resistance (MDR), side effects, and limited applications. To overcome these challenges, a combination of chemotherapy and immunotherapy (monoclonal antibodies, anticancer vaccines, checkpoint inhibitors, and cytokines) has been introduced. Drug delivery systems (DDSs) based on nanotechnology have more applications in BC treatment owing to their controlled and targeted drug release with lower toxicity and reduced adverse drug effects. Several nanocarriers, such as liposomes, nanoparticles, dendrimers, and micelles, have been used for the effective delivery of drugs.

AREAS COVERED

This article presents opportunities and challenges in BC treatment, the rationale for cancer immunotherapy, and several combinational approaches with their applications for BC treatment.

EXPERT OPINION

Nanotechnology can be used for the early prognosis and cure of BC. Several novel and targeted DDSs have been developed to enhance the efficacy of anticancer drugs. This article aims to understand new strategies for the treatment of BC and the appropriate design of nanocarriers used as a combinational DDS.

Beyond immune checkpoint blockade: emerging immunological strategies

The success of checkpoint inhibitors has accelerated the clinical implementation of a vast mosaic of single agents and combination immunotherapies. However, the lack of clinical translation for a number of immunotherapies as monotherapies or in combination with checkpoint inhibitors has clarified that new strategies must be employed to advance the field. The next chapter of immunotherapy should examine the immuno-oncology therapeutic failures, and consider the complexity of immune cell-cancer cell interactions to better design more effective anticancer drugs. Herein, we briefly review the history of immunotherapy and checkpoint blockade, highlighting important clinical failures. We discuss the critical aspects - beyond T cell co-receptors - of immune processes within the tumour microenvironment (TME) that may serve as avenues along which new therapeutic strategies in immuno-oncology can be forged. Emerging insights into tumour biology suggest that successful future therapeutics will focus on two key factors: rescuing T cell homing and dysfunction in the TME, and reappropriating mononuclear phagocyte function for TME inflammatory remodelling. New drugs will need to consider the complex cell networks that exist within tumours and among cancer types.

Nano-Enhanced Cancer Immunotherapy: Immunology Encounters Nanotechnology

Cancer immunotherapy utilizes the immune system to fight cancer and has already moved from the laboratory to clinical application. However, and despite excellent therapeutic outcomes in some hematological and solid cancers, the regular clinical use of cancer immunotherapies reveals major limitations. These include the lack of effective immune therapy options for some cancer types, unresponsiveness to treatment by many patients, evolving therapy resistance, the inaccessible and immunosuppressive nature of the tumor microenvironment (TME), and the risk of potentially life-threatening immune toxicities. Given the potential of nanotechnology to deliver, enhance, and fine-tune cancer immunotherapeutic agents, the combination of cancer immunotherapy with nanotechnology can overcome some of these limitations. In this review, we summarize innovative reports and novel strategies that successfully combine nanotechnology and cancer immunotherapy. We also provide insight into how nanoparticular combination therapies can be used to improve therapy responsiveness, to reduce unwanted toxicity, and to overcome adverse effects of the TME.

Magnetic nanoparticles coated with polyphenols for spatio-temporally controlled cancer photothermal/immunotherapy

As the combination of photothermal therapy (PTT) with immunotherapy provides an effective strategy in cancer treatment, a magnetic nanoparticle delivery system was constructed to load indocyanine green (ICG) and immunostimulator R837 hydrochloride (R837) for spatio-temporally PTT/immunotherapy synergism in cancer. This delivery system is composed of Fe₃O₄ magnetic nanoparticles (MPs) as the core to load ICG and polyethylene glycol polyphenols (DPA-PEG) as the coating layer to load R837, which formed R837 loaded polyphenols coating ICG loaded magnetic nanoparticles (MIRDs). After intravenous injection, the formed MIRDs resulted in long circulation, magnetic resonance imaging (MRI) guides, and magnetic targeting. Once targeting to the tumor, the MIRDs with the near-infrared (NIR) irradiation caused tumor ablation and resulted in tumor-associated antigens releasing to induce the body's immunological response, which was markedly improved it to attack the tumors with the R837 releasing from the outer DPA-PEG. In this case, the synergism of the PTT and immunotherapy inhibited tumor growth, metastasis and recurrence, which resulted in potent anticancer therapeutic effects with few side effect.

A strategy for the selection of monovalent antibodies that span protein dimer interfaces

Ligand-induced dimerization is the predominant mechanism through which secreted proteins activate cell surface receptors to transmit essential biological signals. Cytokines are a large class of soluble proteins that dimerize transmembrane receptors into precise signaling topologies, but there is a need for alternative, engineerable ligand scaffolds that specifically recognize and stabilize these protein interactions. Recombinant antibodies can potentially serve as robust and versatile platforms for cytokine complex stabilization, and their specificity allows for tunable modulation of dimerization equilibrium. Here, we devised an evolutionary strategy to isolate monovalent antibody fragments that bridge together two different receptor subunits in a cytokine-receptor complex, precisely as the receptors are disposed in their natural signaling orientations. To do this, we screened a naive antibody library against a stabilized ligand-receptor ternary complex that acted as a "molecular cast" of the natural receptor dimer conformation. Our selections elicited "stapler" single-chain variable fragments (scFvs) of antibodies that specifically engage the interleukin-4 receptor heterodimer. The 3.1 Å resolution crystal structure of one such stapler revealed that, as intended, this scFv recognizes a composite epitope between the two receptors as they are positioned in the complex. Extending our approach, we evolved a stapler scFv that specifically binds to and stabilizes the interface between the interleukin-2 cytokine and one of its receptor subunits, leading to a 15-fold enhancement in interaction affinity. This demonstration that scFvs can be selected to recognize epitopes that span protein interfaces presents new opportunities to engineer structurally defined antibodies for a broad range of research and therapeutic applications.

Recent advances in nanomaterial-based synergistic combination cancer immunotherapy

This review aims to summarize various synergistic combination cancer immunotherapy strategies based on nanomaterials.

Structural Basis for Signaling Through Shared Common γ Chain Cytokines

The common γ chain (γ_c) family of hematopoietic cytokines consists of six distinct four α-helix bundle soluble ligands that signal through receptors which include the shared γ_c subunit to coordinate a wide range of physiological processes, in particular, those related to innate and adaptive immune function. Since the first crystallographic structure of a γ_c family cytokine/receptor signaling complex (the active Interleukin-2 [IL-2] quaternary complex) was determined in 2005 [1], tremendous progress has been made in the structural characterization of this protein family, transforming our understanding of the molecular mechanisms underlying immune activity. Although many conserved features of γ_c family cytokine complex architecture have emerged, distinguishing details have been observed for individual cytokine complexes that rationalize their unique functional properties. Much work remains to be done in the molecular characterization of γ_c family signaling, particularly with regard to intracellular activation events, and looking forward, new technologies in structural biophysics will offer further insight into the biology of cytokine signaling to inform the design of targeted therapeutics for treatment of immune-linked diseases such as cancer, infection, and autoimmune disorders.

Rational combination immunotherapeutic approaches for effective cancer treatment

Immunotherapy is an important mode of cancer treatment. Over the past decades, immunotherapy has improved the clinical outcome for cancer patients. However, in many cases, mutations in cancer cells, lack of selectivity, insufficiency of tumor-reactive T cells, and host immunosuppression limit the clinical benefit of immunotherapy. Combination approaches in immunotherapy may overcome these obstacles. Accumulating evidence demonstrates that combination immunotherapy is the future of cancer treatment. However, designing safe and rational combinations of immunotherapy with other treatment modalities is critical. This review will discuss the optimal immunotherapy-based combinations mainly with respect to the mechanisms of action of individual therapeutic agents that target multiple steps in evasion and progression of tumor.

Mapping Determinants of Cytokine Signaling via Protein Engineering

Cytokines comprise a large family of secreted ligands that are critical for the regulation of immune homeostasis. Cytokines initiate signaling via dimerization or oligomerization of the cognate receptor subunits, triggering the activation of the Janus Kinases (JAKs)/ signal transducer and activator of transcription (STATs) pathway and the induction of specific gene expression programs and bioactivities. Deregulation of cytokines or their downstream signaling pathways are at the root of many human disorders including autoimmunity and cancer. Identifying and understanding the mechanistic principles that govern cytokine signaling will, therefore, be highly important in order to harness the therapeutic potential of cytokines. In this review, we will analyze how biophysical (ligand-receptor binding geometry and affinity) and cellular (receptor trafficking and intracellular abundance of signaling molecules) parameters shape the cytokine signalosome and cytokine functional pleiotropy; from the initial cytokine binding to its receptor to the degradation of the cytokine receptor complex in the proteasome and/or lysosome. We will also discuss how combining advanced protein engineering with detailed signaling and functional studies has opened promising avenues to tackle complex questions in the cytokine signaling field.

Effects of intratumoral injection of immunoactivator after microwave ablation on antitumor immunity in a mouse model of hepatocellular carcinoma

This study investigated the effects of intratumoral injection of immunoactivator after microwave ablation on antitumor immunity in a mouse model of hepatocellular carcinoma. Hepatocellular carcinoma cell line Hepa1-6 was subcutaneously injected into C57/B6 mice to establish a mouse model of hepatocellular carcinoma. When tumor diameter reached 8 mm, microwave ablation was performed for 3 min with temperature controlled at 55°C. Cytokine sustained-release microspheres (CytoMPS) containing human interleukin-2 (hIL-2) and mouse granulocyte macrophage colony-stimulating factor (mGM-CSF) were injected into the tumor of mice in the experimental group (n=5) at 3, 7 and 14 days after ablation, while sustained-release microspheres containing no cytokine were used in the control group (n=5). Mice were sacrificed on the 17th day after ablation, and CD4⁺ and CD8⁺ T cells in peripheral blood were counted by flow cytometry. Spleen was collected from the mice to isolate lymphocytes. Lactate dehydrogenase (LDH) release assay was used to determine the cytotoxicity of spleen cells to Hepal-6 cells. Injection of CytoMPS after ablation increased the percentage of CD4⁺ and CD8⁺ T cells in peripheral blood. Cytotoxicity of CD8⁺ CTL to Hepal-6 is significantly higher in experimental group than in control group (P<0.01). The results showed that intratumoral injection of CytoMPS containing hIL-2 and mGM-CSF can significantly increase the proportion of CD4⁺ and CD8⁺ T cells in blood and increase the cytotoxicity of CTL cells to tumor cells in mice with hepatocellular carcinoma.

Immunoengineering with biomaterials for enhanced cancer immunotherapy

Cancer immunotherapy has recently shown dramatic clinical success inducing durable response in patients of a wide variety of malignancies. Further improvement of the clinical outcome with immune related cancer treatment requests more exquisite manipulation of a patient's immune system with increased immunity against diseases while mitigating the toxicities. To meet this challenge, biomaterials applied to immunoengineering are being developed to achieve tissue- and/or cell-specific immunomodulation and thus could potentially enhance both the efficacy and safety of current cancer immunotherapies. Here, we review the recent advancement in the field of immunoengineering using biomaterials and their applications in promoting different modalities of cancer immunotherapies, with focus on cell-, antibody-, immunomodulator-, and gene-based immune related treatments and their combinations with conventional therapies. Challenges and opportunities are discussed in applying biomaterials engineering strategies in the development of future cancer immunotherapies. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies Implantable Materials and Surgical Technologies > Nanomaterials and Implants.

Beyond the Oncogene Revolution: Four New Ways to Combat Cancer

It has become clear that tumorigenesis results from much more than just the activation of an oncogene and/or the inactivation of a tumor-suppressor gene, and that the cancer cell genome contains many more alterations than can be specifically targeted at once. This observation has led our group to a search for alternative ways to kill cancer cells (while sparing normal cells) by focusing on properties unique to the former. We have identified four approaches with the potential to generate new anticancer therapies: combatting the tactics by which cancers evade antitumor immune responses, targeting metabolic adaptations that tumor cells use to survive conditions that would kill normal cells, manipulating a cancer cell's response to excessive oxidative stress, and exploiting aneuploidy. This review describes our progress to date on these fronts.

Proteomic-Based Approaches for the Study of Cytokines in Lung Cancer

Proteomic techniques are currently used to understand the biology of different human diseases, including studies of the cell signaling pathways implicated in cancer progression, which is important in knowing the roles of different proteins in tumor development. Due to its poor prognosis, proteomic approaches are focused on the identification of new biomarkers for the early diagnosis, prognosis, and targeted treatment of lung cancer. Cytokines are proteins involved in inflammatory processes and have been proposed as lung cancer biomarkers and therapeutic targets because it has been reported that some cytokines play important roles in tumor development, invasion, and metastasis. In this review, we aim to summarize the different proteomic techniques used to discover new lung cancer biomarkers and therapeutic targets. Several cytokines have been identified as important players in lung cancer using these techniques. We underline the most important cytokines that are useful as biomarkers and therapeutic targets. We also summarize some of the therapeutic strategies targeted for these cytokines in lung cancer.

Pain in an era of armed conflicts: Prevention and treatment for warfighters and civilian casualties

Chronic pain is a common squealae of military- and terror-related injuries. While its pathophysiology has not yet been fully elucidated, it may be potentially related to premorbid neuropsychobiological status, as well as to the type of injury and to the neural alterations that it may evoke. Accordingly, optimized approaches for wounded individuals should integrate primary, secondary and tertiary prevention in the form of thorough evaluation of risk factors along with specific interventions to contravene and mitigate the ensuing chronicity. Thus, Premorbid Events phase may encompass assessments of psychological and neurobiological vulnerability factors in conjunction with fostering preparedness and resilience in both military and civilian populations at risk. Injuries per se phase calls for immediate treatment of acute pain in the field by pharmacological agents that spare and even enhance coping and adaptive capabilities. The key objective of the Post Injury Events is to prevent and/or reverse maladaptive peripheral- and central neural system's processes that mediate transformation of acute to chronic pain and to incorporate timely interventions for concomitant mental health problems including post-traumatic stress disorder and addiction We suggest that the proposed continuum of care may avert more disability and suffering than the currently employed less integrated strategies. While the requirements of the armed forces present a pressing need for this integrated continuum and a framework in which it can be most readily implemented, this approach may be also instrumental for the care of civilian casualties.

A periodic table for cancer

ABSTRACT 

Cancers exhibit differences in metastatic behavior and drug sensitivity that correlate with certain tumor-specific variables such as differentiation grade, growth rate/extent and molecular regulatory aberrations. In practice, patient management is based on the past results of clinical trials adjusted for these biomarkers. Here, it is proposed that treatment strategies could be fine-tuned upfront simply by quantifying tumorigenic spatial (cell growth) and temporal (genetic stability) control losses, as predicted by genetic defects of cell-cycle-regulatory gatekeeper and genome-stabilizing caretaker tumor suppressor genes, respectively. These differential quantifications of tumor dysfunction may in turn be used to create a tumor-specific ‘periodic table’ that guides rational formulation of survival-enhancing anticancer treatment strategies.

Insights into cytokine-receptor interactions from cytokine engineering

Cytokines exert a vast array of immunoregulatory actions critical to human biology and disease. However, the desired immunotherapeutic effects of native cytokines are often mitigated by toxicity or lack of efficacy, either of which results from cytokine receptor pleiotropy and/or undesired activation of off-target cells. As our understanding of the structural principles of cytokine-receptor interactions has advanced, mechanism-based manipulation of cytokine signaling through protein engineering has become an increasingly feasible and powerful approach. Modified cytokines, both agonists and antagonists, have been engineered with narrowed target cell specificities, and they have also yielded important mechanistic insights into cytokine biology and signaling. Here we review the theory and practice of cytokine engineering and rationalize the mechanisms of several engineered cytokines in the context of structure. We discuss specific examples of how structure-based cytokine engineering has opened new opportunities for cytokines as drugs, with a focus on the immunotherapeutic cytokines interferon, interleukin-2, and interleukin-4.

Complex pattern of interleukin-11-induced inflammation revealed by mathematically modeling the dynamics of C-reactive protein

Inflammation underlies many diseases and is an undesired effect of several therapy modalities. Biomathematical modeling can help unravel the complex inflammatory processes and the mechanisms triggering their emergence. We developed a model for induction of C-reactive protein (CRP), a clinically reliable marker of inflammation, by interleukin (IL)-11, an approved cytokine for treatment of chemotherapy-induced thrombocytopenia. Due to paucity of information on the mechanisms underlying inflammation-induced CRP dynamics, our model was developed by systematically evaluating several models for their ability to retrieve variable CRP profiles observed in IL-11-treated breast cancer patients. The preliminary semi-mechanistic models were designed by non-linear mixed-effects modeling, and were evaluated by various performance criteria, which test goodness-of-fit, parsimony and uniqueness. The best-performing model, a robust population model with minimal inter-individual variability, uncovers new aspects of inflammation dynamics. It shows that CRP clearance is a nonlinear self-controlled process, indicating an adaptive anti-inflammatory reaction in humans. The model also reveals a dual IL-11 effect on CRP elevation, whereby the drug has not only a potent immediate influence on CRP incline, but also a long-term influence inducing elevated CRP levels for several months. Consistent with this, model simulations suggest that periodic IL-11 therapy may result in prolonged low-grade (chronic) inflammation post treatment. Future application of the model can therefore help design improved IL-11 regimens with minimized long-term CRP toxicity. Our study illuminates the dynamics of inflammation and its control, and provides a prototype for progressive modeling of complex biological processes in the medical realm and beyond.

Activation of cellular immunity and marked inhibition of liver cancer in a mouse model following gene therapy and tumor expression of GM-SCF, IL-21, and Rae-1

Background

Cancer is both a systemic and a genetic disease. The pathogenesis of cancer might be related to dampened immunity. Host immunity recognizes nascent malignant cells – a process referred to as immune surveillance. Augmenting immune surveillance and suppressing immune escape are crucial in tumor immunotherapy.

Methods

A recombinant plasmid capable of co-expressing granulocyte-macrophage colony- stimulating factor (GM-SCF), interleukin-21 (IL-21), and retinoic acid early transcription factor-1 (Rae-1) was constructed, and its effects determined in a mouse model of subcutaneous liver cancer. Serum specimens were assayed for IL-2 and INF-γ by ELISA. Liver cancer specimens were isolated for Rae-1 expression by RT-PCR and Western blot, and splenocytes were analyzed by flow cytometry.

Results

The recombinant plasmid inhibited the growth of liver cancer and prolonged survival of tumor-loaded mice. Activation of host immunity might have contributed to this effect by promoting increased numbers and cytotoxicity of natural killer (NK) cells and cytotoxic T lymphocytes (CTL) following expression of GM-SCF, IL-21, and Rae-1. By contrast, the frequency of regulatory T cells was decreased, Consequently, activated CTL and NK cells enhanced their secretion of INF-γ, which promoted cytotoxicity of NK cells and CTL. Moreover, active CTL showed dramatic secretion of IL-2, which stimulates CTL. The recombinant expression plasmid also augmented Rae-1 expression by liver cancer cells. Rae-1 receptor expressing CTL and NK cells removed liver cancer.

Conclusions

The recombinant expression plasmid inhibited liver cancer by a mechanism that involved activation of cell-mediated immunity and Rae-1 in liver cancer.

Mobilizing and evaluating anticancer T cells: pitfalls and solutions

Immunotherapy is a promising means to fight cancer, prompting a steady increase in clinical trials and correlative laboratory studies in this field. As antitumor T cells play central roles in immunity against malignant diseases, most immunotherapeutic protocols aim to induce and/or strengthen their function. Various treatment strategies have elicited encouraging clinical responses; however, major challenges have been uncovered that should be addressed in order to fully exploit the potential of immunotherapy. Here, we outline pitfalls for the mobilization of antitumor T cells and offer solutions to improve their therapeutic efficacy. We provide a critical perspective on the main methodologies used to characterize T-cell responses to cancer therapies, with a focus on discrepancies between T-cell attributes measured in vitro and protective responses in vivo. This review altogether provides recommendations to optimize the design of future clinical trials and highlights important considerations for the proficient analysis of clinical specimens available for research.

Cetuximab-mediated tumor regression depends on innate and adaptive immune responses

Epidermal growth factor receptor (EGFR) over-signaling leads to more aggressive tumor growth. The antitumor effect of Cetuximab, an anti-EGFR antibody, depends on oncogenic-signal blockade leading to tumor cell apoptosis and antibody dependent cell-mediated cytotoxicity (ADCC). However, whether adaptive immunity plays a role in Cetuximab-mediated tumor inhibition is unclear, as current xenograft models lack adaptive immunity and human-EGFR-dependent mouse tumor cell lines are unavailable. Using a newly developed xenograft model with reconstituted immune cells, we demonstrate that the Cetuximab effect becomes more pronounced and reduces the EGFR(+) human tumor burden when adaptive immunity is present. To further study this in a mouse tumor model, we created a novel EGFR(+) mouse tumor cell line and demonstrated that Cetuximab-induced tumor regression depends on both innate and adaptive immunity components, including CD8(+) T cells, MyD88, and FcγR. To test whether strong innate signals inside tumor tissues amplifies the Cetuximab-mediated therapeutic effect, Cetuximab was conjugated to CpG. This conjugate is more potent than Cetuximab alone for complete tumor regression and resistance to tumor rechallenge. Furthermore, Cetuximab-CpG conjugates can activate tumor-reactive T cells for tumor regression by increasing dendritic cell (DC) cross-presentation. Therefore, this study establishes new models to evaluate immune responses induced by antibody-based treatment, defines molecular mechanisms, and provides new tumor-regression strategies.

Ex vivo expansion of human CD8+ T cells using autologous CD4+ T cell help

Background

Using in vivo mouse models, the mechanisms of CD4⁺ T cell help have been intensively investigated. However, a mechanistic analysis of human CD4⁺ T cell help is largely lacking. Our goal was to elucidate the mechanisms of human CD4⁺ T cell help of CD8⁺ T cell proliferation using a novel in vitro model.

Methods/Principal Findings

We developed a genetically engineered novel human cell-based artificial APC, aAPC/mOKT3, which expresses a membranous form of the anti-CD3 monoclonal antibody OKT3 as well as other immune accessory molecules. Without requiring the addition of allogeneic feeder cells, aAPC/mOKT3 enabled the expansion of both peripheral and tumor-infiltrating T cells, regardless of HLA-restriction. Stimulation with aAPC/mOKT3 did not expand Foxp3⁺ regulatory T cells, and expanded tumor infiltrating lymphocytes predominantly secreted Th1-type cytokines, interferon-γ and IL-2. In this aAPC-based system, the presence of autologous CD4⁺ T cells was associated with significantly improved CD8⁺ T cell expansion in vitro. The CD4⁺ T cell derived cytokines IL-2 and IL-21 were necessary but not sufficient for this effect. However, CD4⁺ T cell help of CD8⁺ T cell proliferation was partially recapitulated by both adding IL-2/IL-21 and by upregulation of IL-21 receptor on CD8⁺ T cells.

Conclusions

We have developed an in vitro model that advances our understanding of the immunobiology of human CD4⁺ T cell help of CD8⁺ T cells. Our data suggests that human CD4⁺ T cell help can be leveraged to expand CD8⁺ T cells in vitro.

Daedalus: a robust, turnkey platform for rapid production of decigram quantities of active recombinant proteins in human cell lines using novel lentiviral vectors

A key challenge for the academic and biopharmaceutical communities is the rapid and scalable production of recombinant proteins for supporting downstream applications ranging from therapeutic trials to structural genomics efforts. Here, we describe a novel system for the production of recombinant mammalian proteins, including immune receptors, cytokines and antibodies, in a human cell line culture system, often requiring <3 weeks to achieve stable, high-level expression: Daedalus. The inclusion of minimized ubiquitous chromatin opening elements in the transduction vectors is key for preventing genomic silencing and maintaining the stability of decigram levels of expression. This system can bypass the tedious and time-consuming steps of conventional protein production methods by employing the secretion pathway of serum-free adapted human suspension cell lines, such as 293 Freestyle. Using optimized lentiviral vectors, yields of 20–100 mg/l of correctly folded and post-translationally modified, endotoxin-free protein of up to ~70 kDa in size, can be achieved in conventional, small-scale (100 ml) culture. At these yields, most proteins can be purified using a single size-exclusion chromatography step, immediately appropriate for use in structural, biophysical or therapeutic applications.

Interleukin-17-educated monocytes suppress cytotoxic T-cell function through B7-H1 in hepatocellular carcinoma patients

Substantial evidence indicates that inflammation is a critical component of tumor progression. The proinflammatory IL-17-producing cells have recently been detected in tumors, but the effect of IL-17 on antigen-presenting cells in tumors is presently unknown. We recently found that B7-H1(+) macrophages (Mφs) were enriched predominantly in the peritumoral stroma of hepatocellular carcinomas (HCCs). Here, we found a positive correlation between IL-17-producing cells and B7-H1-expressing Mφs in the same area. The B7-H1(+) monocytes/Mφs from HCC tissues expressed significantly more HLA-DR, CD80, and CD86 than B7-H1(-) cells. Accordingly, IL-17 could activate monocytes to express B7-H1 in a dose-dependent manner. Although culture supernatants derived from hepatoma cells also induced B7-H1 expression on monocytes, IL-17 additionally increased hepatoma-mediated B7-H1 expression. Autocrine inflammatory cytokines released from IL-17-activated monocytes stimulated B7-H1 expression. Moreover, these IL-17-exposed monocytes effectively suppressed cytotoxic T-cell immunity in vitro; the effect could be reversed by blocking B7-H1 on those monocytes. Consistent with this, cytotoxic T cells from HCC tissues expressed significant B7-H1 receptor programmed death 1 (PD-1) and exhibited an exhausted phenotype. These data reveal a fine-tuned collaborative action between different stromal cells to counteract T-cell responses in tumors. Such IL-17-mediated immune tolerance should be considered for the rational design of effective immune-based anti-cancer therapies.

Materials from peptide assembly: towards the treatment of cancer and transmittable disease

As the prevalence of cancer and transmittable disease persists, the development of new and more advanced therapies remains a priority in medical research. An emerging platform for the treatment of these illnesses is the use of materials formed via peptide assembly where the bulk material itself acts as the therapeutic. Higher ordered peptide structures with defined chemistry are capable of cellular targeting, recognition, and internalization. Recent design efforts are being made to exploit the nanoscale definition of the materials formed by assembling peptides to target cancer and microbial cells and to function as vaccines. This review focuses on assembled peptide materials that actively participate in the biological processes important to cancer and transmittable diseases to exert an anticipated functional outcome.