Interleukin 12: Basic Biology and Potential Applications in Cancer Treatment

Mathematical modeling and analysis of cancer treatment with radiation and anti-PD-L1

In cancer treatment, radiation therapy (RT) induces direct tumor cell death due to DNA damage, but it also enhances the deaths of radiosensitive immune cells and is followed by local relapse and up-regulation of immune checkpoint ligand PD-L1. Since the binding between PD-1 and PD-L1 curtails anti-tumor immunities, combining RT and PD-L1 inhibitor, anti-PD-L1, is a potential method to improve the treatment efficacy by RT. Some experiments support this hypothesis by showing that the combination of ionizing irradiation (IR) and anti-PD-L1 improves tumor reduction comparing to the monotherapy of IR or anti-PD-L1. In this work, we create a simplified ODE model to study the order of tumor growths under treatments of IR and anti-PD-L1. Our synergy analysis indicates that both IR and anti-PD-L1 improve the tumor reduction of each other, when IR and anti-PD-L1 are given simultaneously. When giving IR and anti-PD-L1 separately, a high dosage of IR should be given first to efficiently reduce tumor load and then followed by anti-PD-L1 with strong efficacy to maintain the tumor reduction and slow down the relapse. Increasing the duration of anti-PD-L1 improves the tumor reduction, but it cannot prolong the duration that tumor relapses to the level of the control case. Under some simplification, we also prove that the model has an unstable tumor free equilibrium and a locally asymptotically stable tumor persistent equilibrium. Our bifurcation diagram reveals a transition from tumor elimination to tumor persistence, as the tumor growth rate increases. In the tumor persistent case, both anti-PD-L1 and IR can reduce tumor amount in the long term.

Different mechanisms of CD200-CD200R induce diverse outcomes in cancer treatment

The CD200 is a cell membrane protein expressed by tumor cells, and its receptor CD200 receptor (CD200R) is expressed by immune cells including macrophages and dendritic cells. The formation of CD200-CD200R inhibits the cellular functions of the targeted immune cells, so CD200 is one type of the immune checkpoint and blockade CD200-CD200R formation is a potential cancer treatment. However, the CD200 blockade has opposite treatment outcomes in different types of cancers. For instance, the CD200R deficient mice have a higher tumor load than the wild type (WT) mice in melanoma suggesting that CD200-CD200R inhibits melanoma. On the other hand, the antibody anti-CD200 treatment in pancreatic ductal adenocarcinoma (PDAC) and head and neck squamous cell carcinoma (HNSCC) significantly reduces the tumor load indicating that CD200-CD200R promotes PDAC and HNSCC. In this work, we hypothesize that different mechanisms of CD200-CD200R in tumor microenvironment could be one of the reasons for the diverse treatment outcomes of CD200 blockade in different types of cancers. We create one Ordinary Differential Equations (ODEs) model for melanoma including the inhibition of CCL8 and regulatory T cells and the switching from M2 to M1 macrophages by CD200-CD200R to capture the tumor inhibition by CD200-CD200R. We also create another ODEs model for PDAC and HNSCC including the promotion of the polarization and suppressive activities of M2 macrophages by CD200-CD200R to generate the tumor promotion by CD200-CD200R. Furthermore, we use these two models to investigate the treatment efficacy of the combination treatment between the CD200-CD200R blockade and the other immune checkpoint inhibitor, anti-PD-1. Our result shows that different mechanisms of CD200-CD200R can induce different treatment outcomes in combination treatments, namely, only the CD200-CD200R blockade reduces tumor load in melanoma and only the anti-PD-1 and CD200 knockout decrease tumor load in PDAC and HNSCC. Moreover, in melanoma, the CD200-CD200R mainly utilizes the inhibitions on M1 macrophages and dendritic cells to inhibit tumor growth, instead of M2 macrophages.

Layer-by-layer interleukin-12 nanoparticles drive a safe and effective response in ovarian tumors

Ovarian cancer is especially deadly, challenging to treat, and has proven refractory to known immunotherapies. Cytokine therapy is an attractive strategy to drive a proinflammatory immune response in immunologically cold tumors such as many high grade ovarian cancers; however, this strategy has been limited in the past due to severe toxicity. We previously demonstrated the use of a layer-by-layer (LbL) nanoparticle (NP) delivery vehicle in subcutaneous flank tumors to reduce the toxicity of interleukin-12 (IL-12) therapy upon intratumoral injection. However, ovarian cancer cannot be treated by local injection as it presents as dispersed metastases. Herein, we demonstrate the use of systemically delivered LbL NPs using a cancer cell membrane-binding outer layer to effectively target and engage the adaptive immune system as a treatment in multiple orthotopic ovarian tumor models, including immunologically cold tumors. IL-12 therapy from systemically delivered LbL NPs shows reduced severe toxicity and maintained anti-tumor efficacy compared to carrier-free IL-12 or layer-free liposomal NPs leading to a 30% complete survival rate.

Mathematical Modeling and Analysis of CD200-CD200R in Cancer Treatment

CD200 is a cell membrane protein that binds to its receptor, CD200 receptor (CD200R). The CD200 positive tumor cells inhibit the cellular functions of M1 and M2 macrophages and dendritic cells (DCs) through the CD200-CD200R complex, resulting in downregulation of Interleukin-10 and Interleukin-12 productions and affecting the activation of cytotoxic T lymphocytes. In this work, we provide two ordinary differential equation models, one complete model and one simplified model, to investigate how the binding affinities of CD200R and the populations of M1 and M2 macrophages affect the functions of the CD200-CD200R complex in tumor growth. Our simulations demonstrate that (i) the impact of the CD200-CD200R complex on tumor promotion or inhibition highly depends on the binding affinity of the CD200R on M2 macrophages and DCs to the CD200 on tumor cells, and (ii) a stronger binding affinity of the CD200R on M1 macrophages or DCs to the CD200 on tumor cells induces a higher tumor cell density in the CD200 positive tumor. Thus, the CD200 blockade would be an efficient treatment method in this case. Moreover, the simplified model shows that the binding affinity of CD200R on macrophages is the major factor to determine the treatment efficacy of CD200 blockade when the binding affinities of CD200R on M1 and M2 macrophages are significantly different to each other. On the other hand, both the binding affinity of CD200R and the population of macrophages are the major factors to determine the treatment efficacy of CD200 blockade when the binding affinities of CD200R on M1 and M2 macrophages are close to each other. We also analyze the simplified model to investigate the dynamics of the positive and trivial equilibria of the CD200 positive tumor case and the CD200 deficient tumor case. The bifurcation diagrams show that when M1 macrophages dominate the population, the tumor cell density of the CD200 positive tumor is higher than the one of CD200 deficient tumor. Moreover, the dynamics of tumor cell density change from tumor elimination to tumor persistence to oscillation, as the maximal proliferation rate of tumor cells increases.

CD40 monoclonal antibody and OK432 synergistically promote the activation of dendritic cells in immunotherapy

Background

Colorectal cancer (CRC) with pulmonary metastasis usually indicates a poor prognosis, whereas patients may benefit from adoptive cell therapy. Tumor-specific cytotoxic T lymphocytes (CTLs) have been reported as a promising treatment for CRC. However, the antitumor effect of CTLs remains limited partially due to insufficient production of effector cells via the activation by antigen-presenting dendritic cells (DCs).

Method

This study showed that a combination of CD40 mAb and Picibanil (OK-432) could significantly enhance the activation of CTLs by DCs, both in vitro and in vivo. Flow cytometry, colon cancer mouse model, and pathological staining were employed to demonstrate the specific functions.

Results

This approach promoted the maturation of DCs, augmented the production of stimulatory cytokines, and suppressed the secretion of inhibitory cytokines. Additionally, it facilitated the killing efficiency of CTLs via stimulating their proliferation while restraining the number of Tregs, concomitantly with the positive regulation of corresponding cytokines. Furthermore, the combined unit could hurdle the expansion of tumor cells on metastatic lungs in the colon cancer mouse model.

Conclusion

Collectively, the combination of CD40-mAb and OK-432 facilitated the maturation of DCs and enhanced the cytotoxicity of T cells, promising therapeutic approach against CRC.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02630-x.

Ultraviolet Radiation and Basal Cell Carcinoma: An Environmental Perspective

Ultraviolet radiation (UVR) is a known carcinogen participated for the development of skin cancers. Solar UVR exposure, particularly ultraviolet B (UVB), is the mostly significant environmental risk factor for the occurrence and progress of basal cell carcinoma(BCC). Both cumulative and intermittent high-grade UVR exposure could promote the uncontrolled replication of skin cells. There are also exsiting other contributing environmental factors that combine with the UVR exposure to promote the development of BCC. DNA damage in formation of skin cancers is considered to be a result of UVR toxicity. It is UVR that could activate a series of oncogenes simultaneously inactivating tumor suppressor genes and aberrant proliferation and survival of keratinocytes that repair these damages. Furthermore, mounting evidence demonstrates that inflammatory responses of immune cells in the tumor microenvironment plays crucial role in the skin tumorigenesis as well. In this chapter, we will follow the function of UVR in the onset and development of BCC. We describe the factors that influence BCC induced by UVR, and also review the recent advances of pathogenesis of BCC induced by UVR from the genetic and inflammatory aspects.

Cancer Cell Coating Nanoparticles for Optimal Tumor-Specific Cytokine Delivery

Although cytokine therapy is an attractive strategy to build a more robust immune response in tumors, cytokines have faced clinical failures due to toxicity. In particular, interleukin-12 has shown great clinical promise but was limited in translation because of systemic toxicity. In this study, we demonstrate an enhanced ability to reduce toxicity without affecting the efficacy of IL-12 therapy. We engineer the material properties of a NP to meet the enhanced demands for optimal cytokine delivery by using the layer-by-layer (LbL) approach. Importantly, using LbL, we demonstrate cell-level trafficking of NPs to preferentially localize to the cell's outer surface and act as a drug depot, which is required for optimal payload activity on neighboring cytokine membrane receptors. LbL-NPs showed efficacy against a tumor challenge in both colorectal and ovarian tumors at doses that were not tolerated when administered carrier-free.

Temporal changes within the (bladder) tumor microenvironment that accompany the therapeutic effects of the immunocytokine NHS-IL12

BACKGROUND

While significant strides in the treatment of metastatic bladder cancer have been made with immune checkpoint inhibitors, the treatment of carcinoma in situ and non-muscle invasive, non-metastatic (superficial) human urothelial carcinoma, also termed non-muscle invasive bladder cancer (NMIBC), remains intractable with bacillus Calmette-Guerin (BCG) employed as the standard of care. In this study, an immunocytokine, NHS-muIL12, which consists of two molecules of murine IL-12 fused to NHS76, a tumor necrosis-targeting human IgG1, was examined as an immunotherapeutic in an orthotopic MB49^luc bladder tumor model.

METHODS

The antitumor activity of systemic administration of NHS-muIL12 was investigated on MB49^luc tumors, an aggressive, bioluminescent orthotopic bladder cancer model. Temporal studies were carried out on MB49^luc bladder tumors harvested during various time points during NHS-muIL12 treatment and cellular changes associated with the reduction in tumor burden following NHS-muIL12 were determined by flow cytometry. Effects of those changes on the proliferation/activation of lymphoid cells were also determined.

RESULTS

Studies revealed a significant reduction in MB49^luc bladder tumor burden occurring between days 3 and 6 after the third and final systemic administration of NHS-muIL12. Temporal analyses of the MB49^luc bladder tumor microenvironment (TME) initially revealed a large accumulation of myeloid-derived suppressor cells (MDSCs) and macrophages that elicited potent immunosuppression. Immunosuppression was characterized by the inability of CD4⁺ and CD8⁺ T cells to respond to broad-based immune stimulants. NHS-muIL12 administration resulted in temporal-dependent reductions in the number of MDSCs, macrophages and tumor-associated TGF-β, which culminated in a re-ignition of CD4⁺ and CD8⁺ T cells to elicit potent antitumor responses against MB49^luc bladder tumors.

CONCLUSIONS

These findings provide strong evidence that the systemic administration of an immunocytokine consisting of a tumor-targeting Ig through recognition of DNA and DNA-histone complexes coupled to muIL-12 can effectively target the bladder TME; this significantly reduces the myeloid cellular compartment and reverts an immunosuppressive to an immunopermissive TME, ultimately resulting in antitumor effects. These studies provide further rationale for the employment of NHS-IL12 as an immunomodulator and clinical immunotherapeutic for NMIBC.

GEN-1 immunotherapy for the treatment of ovarian cancer

GEN-1 is a gene-based immunotherapy, comprising a human IL-12 gene expression plasmid and a synthetic plasmid delivery system, delivered intraperitoneally (ip.) to produce local and persistent levels of a pleiotropic immunocytokine, IL-12, at the tumor site in patients with advanced ovarian cancer. The goal of local and persistent IL-12 delivery is to remodel the highly immunosuppressive tumor microenvironment to favor immune stimulation while avoiding serious systemic toxicities, a major limitation of recombinant IL-12 therapy. Safe and sustained local production of IL-12 and related immunocytokines at the tumor site could produce potentially more favorable immunological changes in the tumor microenvironment and antitumor responses than a bolus systemic delivery of recombinant IL-12. Treatment safety, clinical benefits and biological activity of GEN-1 ip. in patients with ovarian cancer and in representative animal models are described.

Dietary proanthocyanidins prevent ultraviolet radiation-induced non-melanoma skin cancer through enhanced repair of damaged DNA-dependent activation of immune sensitivity

Numerous plant products have been used to prevent and manage a wide variety of diseases for centuries. These products are now considered as promising options for the development of more effective and less toxic alternatives to the systems of medicine developed primarily in developed countries in the modern era. Grape seed proanthocyanidins (GSPs) are of great interest due to their anti-carcinogenic effects that have been demonstrated using various tumor models including ultraviolet (UV) radiation-induced non-melanoma skin cancer. In a pre-clinical mouse model supplementation of a control diet (AIN76A) with GSPs at concentrations of 0.2% and 0.5% (w/w) significantly inhibits the growth and multiplicity of UVB radiation-induced skin tumors. In this review, we summarize the evidence that this inhibition of UVB-induced skin tumor development by dietary GSPs is mediated by a multiplicity of coordinated effects including: (i) Promotion of the repair of damaged DNA by nuclear excision repair mechanisms, and (ii) DNA repair-dependent stimulation of the immune system following the functional activation of dendritic cells and effector T cells. Dietary GSPs hold promise for the development of an effective alternative strategy for the prevention of excessive solar UVB radiation exposure-induced skin diseases including the risk of non-melanoma skin cancer in humans.

Immunomodulatory Activity of VEGF in Cancer

The ability of tumor cells to escape tumor immunosurveillance contributes to cancer development. Factors produced in the tumor microenvironment create "tolerizing" conditions and thereby help the tumor to evade antitumoral immune responses. VEGF-A, already known for its major role in tumor vessel growth (neoangiogenesis), was recently identified as a key factor in tumor-induced immunosuppression. In particular, VEGF-A fosters the proliferation of immunosuppressive cells, limits T-cell recruitment into tumors, and promotes T-cell exhaustion. Antiangiogenic therapies have shown significant efficacy in patients with a variety of solid tumors, preventing tumor progression by limiting tumor-induced angiogenesis. VEGF-targeting therapies have also been shown to modulate the tumor-induced immunosuppressive microenvironment, enhancing Th1-type T-cell responses and increasing tumor infiltration by T cells. The immunomodulatory properties of VEGF-targeting therapies open up new perspectives for cancer treatment, especially through strategies combining antiangiogenic drugs with immunotherapy. Preclinical models and early clinical studies of these combined approaches have given promising results.

Adjuvants and myeloid-derived suppressor cells: enemies or allies in therapeutic cancer vaccination

Adjuvants are a critical but largely overlooked and poorly understood component included in vaccine formulations to stimulate and modulate the desired immune responses to an antigen. However, unlike in the protective infectious disease vaccines, adjuvants for cancer vaccines also need to overcome the effect of tumor-induced suppressive immune populations circulating in tumor-bearing individuals. Myeloid-derived suppressor cells (MDSC) are considered to be one of the key immunosuppressive populations that inhibit tumor-specific T cell responses in cancer patients. This review focuses on the different signals for the activation of the immune system induced by adjuvants, and the close relationship to the mechanisms of recruitment and activation of MDSC. This work explores the possibility that a cancer vaccine adjuvant may either strengthen or weaken the effect of tumor-induced MDSC, and the crucial need to address this in present and future cancer vaccines.

The immunocytokine NHS-IL12 as a potential cancer therapeutic

Targeted delivery of IL-12 might turn this cytokine into a safer, more effective cancer therapeutic. Here we describe a novel immunocytokine, NHS-IL12, consisting of two molecules of IL-12 fused to a tumor necrosis-targeting human IgG1 (NHS76). The addition of the human IgG1 moiety resulted in a longer plasma half-life of NHS-IL12 than recombinant IL-12, and a selective targeting to murine tumors in vivo. Data from both in vitro assays using human PBMCs and in vivo primate studies showed that IFN-gamma production by immune cells is attenuated following treatment with the immunocytokine, suggesting an improved toxicity profile than seen with recombinant IL-12 alone. NHS-IL12 was superior to recombinant IL-12 when evaluated as an anti-tumor agent in three murine tumor models. Mechanistic studies utilizing immune cell subset-depleting antibodies, flow cytometric methods, and in vitro cytotoxicity and ELISA assays all indicated that the anti-tumor effects of NHS-IL12 were primarily CD8+ T cell-dependent and likely IL-12-mediated. Combining NHS-IL12 treatment with a cancer vaccine, radiation, or chemotherapy resulted in greater anti-tumor effects than each individual therapy alone. These preclinical findings provide a rationale for the clinical testing of this immunocytokine, both as a single agent and in combination with vaccines, radiation and chemotherapy.

Ultraviolet radiation-induced non-melanoma skin cancer: Regulation of DNA damage repair and inflammation

Exposure to ultraviolet (UV) radiation is associated with approximately 65% of melanoma cases, and 90% of non-melanoma skin cancers (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). While the incidence of most other malignancies has either stabilized or declined, that of NMSC has increased and is developing even in younger age groups. NMSCs account for nearly 15,000 deaths, 3.5 million new cases, and more than 3 billion dollars a year in medical costs in the United States alone, representing a major public health concern. As sun protection efforts have not been proven effective, targeted chemoprevention strategies are much needed. Skin carcinogenesis by DNA damage is considered a predominant paradigm for UV toxicity. Exposure to UV radiation can activate various oncogenes while inactivating tumor suppressor genes, resulting in inappropriate survival and proliferation of keratinocytes that harbor these damages. Moreover, increasing evidence demonstrate that inflammatory responses by the immune cells within the tumor microenvironment also contribute significantly to skin tumorigenesis. Initiation and progression of skin carcinogenesis mediated by UV radiation involve complex pathways, including those of apoptosis, proliferation, autophagy, DNA repair, checkpoint signaling, metabolism, and inflammation. In this review, we highlight the recent advances in two of these key molecular processes that result in UV-mediated skin carcinogenesis. In particular, we discuss 1) pathways that regulate DNA damage repair and 2) the regulation of the inflammatory process its crosstalk with DNA repair potentially leading to non-melanoma skin carcinogenesis.

Mathematical modeling of Interleukin-35 promoting tumor growth and angiogenesis

Interleukin-35 (IL-35), a cytokine from the Interleukin-12 cytokine family, has been considered as an anti-inflammatory cytokine which promotes tumor progression and tumor immune evasion. It has also been demonstrated that IL-35 is secreted by regulatory T cells. Recent mouse experiments have shown that IL-35 produced by cancer cells promotes tumor growth via enhancing myeloid cell accumulation and angiogenesis, and reducing the infiltration of activated CD8[Formula: see text] T cells into tumor microenvironment. In the present paper we develop a mathematical model based on these experimental results. We include in the model an anti-IL-35 drug as treatment. The extended model (with drug) is used to design protocols of anti-IL-35 injections for treatment of cancer. We find that with a fixed total amount of drug, continuous injection has better efficacy than intermittent injections in reducing the tumor load while the treatment is ongoing. We also find that the percentage of tumor reduction under anti-IL-35 treatment improves when the production of IL-35 by cancer is increased.

Systematic Review of Interleukin-12, Interleukin-17, and Interleukin-23 Pathway Inhibitors for the Treatment of Moderate-to-Severe Chronic Plaque Psoriasis

Background:

Monoclonal antibodies known as biologic agents specifically targeted against interleukin-12 (IL-12), interleukin-17A (IL-17), and interleukin-23 (IL-23) have been the focus of research for moderate-to-severe chronic plaque psoriasis in recent years.

Objectives:

To discuss the immune-mediated model of psoriasis and to summarize current knowledge of the clinical efficacy and safety of new biologic agents for moderate-to-severe chronic plaque psoriasis.

Methods:

The PubMed database was searched for relevant articles on ustekinumab, briakinumab, tildrakizumab (MK-322), guselkumab, secukinumab, ixekizumab, and brodalumab published between January 2005 and July 2013.

Results:

Fifty-five articles were identified. These studies suggest that the biologic agents specifically targeting IL-12, IL-17, and IL-23 are efficacious and safe in the treatment of moderate-to-severe psoriasis in adults.

Conclusion:

Current data from clinical trials suggest that biologic agents targeting IL-12, IL-17, and IL-23 are safe and efficacious drugs for use in moderate-to-severe chronic plaque psoriasis. Long-term data still need to be established.

Current and potential immune therapies and vaccines in the management of psoriasis

Psoriasis is a chronic, immune skin disease associated with significant morbidity. Development of psoriasis is influenced by numerous genes, one allele is HLA-CW*0602. Other genes and single nucleotide polymorphisms affect immunologic pathways and antimicrobial peptide synthesis. Dendritic cells initiate psoriasis by activating T-cells toward a Th1 and Th17 response, with increased cytokines including TNF-α, IL-6, -12, -17, -22, and -23. IL-22 appears to promote keratinocyte dedifferentiation and increased antimicrobial peptide synthesis while TNF-α and IL-17 induce leukocyte localization within the psoriatic plaque. These recent insights identifying key cytokine pathways have led to the development of inhibitors with significant efficacy in the treatment of psoriasis. While a strategy for vaccine modulation of the immune response in psoriasis is in progress, with new technology they may provide a cost-effective long-term treatment that may induce tolerance or targeted self-inhibition for patients with autoimmune disorders, such as psoriasis.

Drug therapies in dermatology

This article explores the current and emerging therapies for skin disease, with a particular focus on chronic plaque psoriasis and metastatic malignant melanoma. We discuss the current biological therapies used for psoriasis and those on the horizon, including small molecules and biosimilars. We also summarise the recent advances in the use of novel therapeutic agents in other dermatological diseases and outline the promise of translational research and stratified medicine approaches in dermatology. Better matching of patients with therapies is anticipated to have a major effect on both clinical practice and the development of new drugs and diagnostics.

Depletion of myeloid-derived suppressor cells during interleukin-12 immunogene therapy does not confer a survival advantage in experimental malignant glioma

Myeloid-derived suppressor cells (MDSCs) accumulate in the glioma microenvironment during tumor progression and promote immunosuppression. Interleukin-12 (IL-12) immunogene therapy can alter MDSCs toward an antigen-presenting cell phenotype and these mature cells can have a central role in antigen presentation. It remains unclear, however, how MDSC depletion can affect glioma immunotherapy. In this study, we generated a replication-deficient adenoviral vector, Ad.5/3.cRGD-mIL12p70, that transduces the GL261-based murine glioma cell line, resulting in the induction of biologically active, murine IL12p70 expression. Ex vivo, IL-12 expressed by GL261 cells induced interferon-γ synthesis in CD8(+) T cells (P<0.001), CD4(+) T cells (P=0.009) and natural killer cells (P=0.036). When injected 1 week after tumor implantation, Ad.5/3.cRGD-mIL12p70 successfully prolonged the survival of glioma-bearing mice. Sixty percent of animals treated with IL-12 immunotherapy were long-term survivors over 175 days, whereas all the control group animals expired by 40 days after tumor implantation (P=0.026). Mice receiving Ad.5/3.cRGD-mIL12p70 also accumulated 50% less MDSCs in the brain than the control group (P=0.007). Moreover, in the IL-12 group, MDSCs significantly overexpressed CD80 and major histocompatibility complex class II molecules (P=0.041). Depletion of MDSCs with Gr1(+) antibody had no survival benefit induced by IL-12-mediated immunotherapy. Of note, IL-12 therapy increased the presence of myeloid dendritic cells (mDCs) in the glioma microenvironment (P=0.0069). Ultimately, the data show that in the context of IL-12 immunogene therapy, MDSCs are dispensable and mDCs may provide the majority of antigen presentation in the brain.

Adenovirus-Based Vectors for the Development of Prophylactic and Therapeutic Vaccines

Emerging and reemerging infectious diseases as well as cancer pose great global health impacts on the society. Vaccines have emerged as effective treatments to prevent or reduce the burdens of already developed diseases. This is achieved by means of activating various components of the immune system to generate systemic inflammatory reactions targeting infectious agents or diseased cells for control/elimination. DNA virus-based genetic vaccines gained significant attention in the past decades owing to the development of DNA manipulation technologies, which allowed engineering of recombinant viral vectors encoding sequences for foreign antigens or their immunogenic epitopes as well as various immunomodulatory molecules. Despite tremendous progress in the past 50 years, many hurdles still remain for achieving the full clinical potential of viral-vectored vaccines. This chapter will present the evolution of vaccines from “live” or “attenuated” first-generation agents to recombinant DNA and viral-vectored vaccines. Particular emphasis will be given to human adenovirus (Ad) for the development of prophylactic and therapeutic vaccines. Ad biological properties related to vaccine development will be highlighted along with their advantages and potential hurdles to be overcome. In particular, we will discuss (1) genetic modifications in the Ad capsid protein to reduce the intrinsic viral immunogenicity, (2) antigen capsid incorporation for effective presentation of foreign antigens to the immune system, (3) modification of the hexon and fiber capsid proteins for Ad liver de-targeting and selective retargeting to cancer cells, (4) Ad-based vaccines carrying “arming” transgenes with immunostimulatory functions as immune adjuvants, and (5) oncolytic Ad vectors as a new therapeutic approach against cancer. Finally, the combination of adenoviral vectors with other non-adenoviral vector systems, the prime/boost strategy of immunization, clinical trials involving Ad-based vaccines, and the perspectives for the field development will be discussed.

Soypeptide lunasin in cytokine immunotherapy for lymphoma

Immunostimulatory cytokines can enhance anti-tumor immunity and are part of the therapeutic armamentarium for cancer treatment. We have previously reported that post-transplant lymphoma patients have an acquired deficiency of signal transducer and activator of transcription 4, which results in defective IFNγ production during clinical immunotherapy. With the goal of further improving cytokine-based immunotherapy, we examined the effects of a soybean peptide called lunasin that synergistically works with cytokines on natural killer (NK) cells. Peripheral blood mononuclear cells of healthy donors and post-transplant lymphoma patients were stimulated with or without lunasin in the presence of IL-12 or IL-2. NK activation was evaluated, and its tumoricidal activity was assessed using in vitro and in vivo tumor models. Chromatin immunoprecipitation assay was performed to evaluate the histone modification of gene loci that are regulated by lunasin and cytokine. Adding lunasin to IL-12- or IL-2-stimulated NK cells demonstrated synergistic effects in the induction of IFNG and GZMB involved in cytotoxicity. The combination of lunasin and cytokines (IL-12 plus IL-2) was capable of restoring IFNγ production by NK cells from post-transplant lymphoma patients. In addition, NK cells stimulated with lunasin plus cytokines displayed higher tumoricidal activity than those stimulated with cytokines alone using in vitro and in vivo tumor models. The underlying mechanism responsible for the effects of lunasin on NK cells is likely due to epigenetic modulation on target gene loci. Lunasin represents a different class of immune modulating agent that may augment the therapeutic responses mediated by cytokine-based immunotherapy.

Molecular mechanisms of mouse skin tumor promotion

Multiple molecular mechanisms are involved in the promotion of skin carcinogenesis. Induction of sustained proliferation and epidermal hyperplasia by direct activation of mitotic signaling pathways or indirectly in response to chronic wounding and/or inflammation, or due to a block in terminal differentiation or resistance to apoptosis is necessary to allow clonal expansion of initiated cells with DNA mutations to form skin tumors. The mitotic pathways include activation of epidermal growth factor receptor and Ras/Raf/mitogen-activated protein kinase signaling. Chronic inflammation results in inflammatory cell secretion of growth factors and cytokines such as tumor necrosis factor-α and interleukins, as well as production of reactive oxygen species, all of which can stimulate proliferation. Persistent activation of these pathways leads to tumor promotion.

Adenosine as an endogenous immunoregulator in cancer pathogenesis: where to go?

Cancer is a chronic disease and its pathogenesis is well correlated with infection and inflammation. Adenosine is a purine nucleoside, which is produced under metabolic stress like hypoxic conditions. Acute or chronic inflammatory conditions lead to the release of precursor adenine nucleotides (adenosine triphosphate (ATP), adenosien diphosphate (ADP) and adenosine monophosphate (AMP)) from cells, which are extracellularly catabolized into adenosine by extracellular ectonucleotidases, i.e., CD39 or nucleoside triphosphate dephosphorylase (NTPD) and CD73 or 5'-ectonucleotidase. It is now well-known that adenosine is secreted by cancer as well as immune cells during tumor pathogenesis under metabolic stress or hypoxia. Once adenosine is released into the extracellular environment, it exerts various immunomodulatory effects via adenosine receptors (A1, A2A, A2B, and A3) expressed on various immune cells (i.e., macrophages, myeloid-derived suppressor cells (MDSCs), natural killer (NK) cells, dendritic cells (DCs), T cells, regulatory T cell (Tregs), etc.), which play very important roles in the pathogenesis of cancer. This review is intended to summarize the role of inflammation and adenosine in the immunopathogenesis of tumor along with regulation of tumor-specific immune response and its modulation as an adjunct approach to tumor immunotherapy.

The effect of a year of highly active antiretroviral therapy on immune reconstruction and cytokines in HIV/AIDS patients

To investigate the effect of a year of highly active antiretroviral therapy (HAART) on immune reconstruction and cytokine production in HIV/AIDS patients, 35 AIDS patients were recruited for HAART treatment and 35 healthy volunteers were assigned as controls. The dynamic changes in HIV load, blood T cell subset counts, as well as interleukin (IL)-12, interferon (IFN)-γ, and interferon-inducible protein-10 (IP-10) levels in AIDS patients were evaluated before HAART and at 6 and 12 months after therapy. Our results revealed that HIV virus load in HIV/AIDS patients was reduced below the detectable limit after patients received 6 months of HAART. CD3(+)CD4(+), CD4(+)CD45RA(+)62L(+), and CD4(+)CD45RO(+) T cells were found to be significantly decreased in HIV/AIDS patients compared to the healthy controls, but increased after HAART. CD3(+)CD8(+) and CD8(+)CD38(+) cells were found to be increased in HIV/AIDS patients but decreased after HAART. Plasma IL-12 and IFN-γ levels were lower but IP-10 level was higher in AIDS patients compared to controls. HAART significantly improved IL-12 and IFN- γ levels but reduced IP-10 level in AIDS patients (p<0.01). CD4(+)CD45RA(+)62L(+) and CD4(+)CD45RO(+) T cells were positively correlated with plasma IL-12/IFN-γ levels (p<0.05), but negatively correlated with plasma IP-10 level. However, CD3(+)CD8(+) cells were negatively correlated with plasma IL-12 and IFN-γ levels, but positively correlated with IP-10 level (p<0.05). HAART benefits HIV/AIDS patients by not only inhibiting virus replication but also by contributing to immune reconstruction, such as restoring subsets of T cells and adjusting cytokine production in HIV/AIDS patients.

The role of CD200-CD200R in tumor immune evasion

CD200 is a cell membrane protein that interacts with CD200 receptor (CD200R) of myeloid lineage cells. During tumor initiation and progression, CD200-positive tumor cells can interact with M1 and M2 macrophages through CD200-CD200R-compex, and downregulate IL-10 and IL-12 productions secreted primarily by M2 and M1 macrophages, respectively. In the tumor microenvironment, IL-10 inhibits the activation of cytotoxic T lymphocytes (CTL), while IL-12 enhances CTL activation. In this paper, we used a system approach to determine the combined effect of CD200-CD200R interaction on tumor proliferation by developing a mathematical model. We demonstrate that blocking CD200 on tumor cells may have opposite effects on tumor proliferation depending on the "affinity" of the macrophages to form the CD200-CD200R-complex with tumor cells. Our results help understanding the complexities of tumor microenvironment.

Micro-RNAs in inflammatory diseases and as a link between inflammation and cancer

OBJECTIVE

The objective of this review is to examine the role of miRNA in various inflammatory diseases and in inflammatory diseases progressing to cancer.

INTRODUCTION

MicroRNAs are small, conserved, non-coding RNA molecules which are present in most of the eukaryotes. miRNA have been reported to play a major role in the physiological control of gene expression and in the pathogenesis of various diseases. They regulate the gene expression mainly at the post-transcriptional level. miRNA expression profile is reported to be altered in various inflammatory diseases and subsequently affects the expression of genes, which is important in disease pathogenesis.

METHODS

A Pubmed database search was performed for studies related to miRNA studies in inflammatory disease, cancer and in inflammatory diseases progressing to cancer.

CONCLUSION

The evidence shows very important role of miRNA in inflammatory diseases. Few miRNAs involved in common inflammatory process and suggest miRNA as a link between inflammation and cancer. Future research should be directed to use miRNA therapeutically to target common inflammatory pathway and to develop miRNA as biomarker to detect development of cancer at early stages.

Silibinin inhibits ultraviolet B radiation-induced DNA-damage and apoptosis by enhancing interleukin-12 expression in JB6 cells and SKH-1 hairless mouse skin

Recent studies have demonstrated silibinin efficacy against ultraviolet B (UVB)-induced skin carcinogenesis via different mechanisms in cell lines and animal models; however, its role in regulating interleukin-12 (IL-12), an immunomodulatory cytokine that reduces UVB-induced DNA damage and apoptosis, is not known. Here, we report that UVB irradiation causes caspase 3 and PARP cleavage and apoptosis, and addition of recombinant IL-12 or silibinin immediately after UVB significantly protects UVB-induced apoptosis in JB6 cells. IL-12 antibody-mediated blocking of IL-12 activity compromised the protective effects of both IL-12 and silibinin. Both silibinin and IL-12 also accelerated the repair of UVB-caused cyclobutane-pyrimidine dimers (CPDs) in JB6 cells. Additional studies confirmed that indeed silibinin causes a significant increase in IL-12 levels in UVB-irradiated JB6 cells as well as in mouse skin epidermis, and that similar to cell-culture findings, silibinin topical application immediately after UVB exposure causes a strong protection against UVB-induced TUNEL positive cells in epidermis possibly through a significantly accelerated repair of UVB-caused CPDs. Together, these findings for the first time provide an important insight regarding the pharmacological mechanism wherein silibinin induces endogenous IL-12 in its efficacy against UVB-caused skin damages. In view of the fact that an enhanced endogenous IL-12 level could effectively remove UVB-caused DNA damage and associated skin cancer, our findings suggest that the use of silibinin in UVB-damaged human skin would also be a practical and translational strategy to manage solar radiation-caused skin damages as well as skin cancer.

Pharmacokinetics of combined gene therapy expressing constitutive human GM-CSF and hyperthermia-regulated human IL-12

Background

An adenovirus that expresses both interleukin (IL)-12 and granulocyte-macrophage colony-stimulating-factor (GM-CSF) has been proven to be very effective in treating several tumors, but causes serious normal tissue toxicities.

Methods

In this study, a novel adenoviral vector was constructed by placing the human GM-CSF gene under the control of the CMV-IE promoter and human IL-12 gene under the control of heat shock protein 70B gene promoter. Both hGM-CSF and hIL-12 expressions in virus-infected tumor cells were analyzed in vitro and in vivo when underlying single or multiple rounds of hyperthermia.

Results

We observed constitutive high expression of human GM-CSF and heat-induced expression of human IL-12 after a single round of hyperthermia post viral infection. The heat-induced hIL-12 expression exhibited a pulse-like pattern with a peak at 24 hrs followed by a decline 48 hrs post heat stress. Repeated heat treatment was more effective in inducing hIL-12 expression than a one-time heat treatment. Interestedly, we also observed that constitutive expression of hGM-CSF could be stimulated by heat stress in tested tumor cells.

Conclusion

Our study provided a novel strategy for combined gene therapy that allows constitutive expression of a non-toxic gene such as GM-CSF and heat-induced expression of a toxic gene such as IL-12. In addition, our study also showed that hyperthermia can be used to trigger gene expression in temporal and special manner.

Current and emerging systemic treatment strategies for psoriasis

Psoriasis is a common chronic inflammatory disease of the skin that has a significant impact on quality of life. A small number of systemic therapies are well established in psoriasis management. These have immunosuppressive and/or anti-proliferative effects on the skin and immune system. As understanding of the pathogenesis of psoriasis has advanced over the last 2 decades, there has been clearer appreciation of the genetic, cellular and immunological components of disease expression, which has provided new insight into potential therapeutic targets, including the development of biological therapies. Biologics offer a unique opportunity to block or inhibit specific key components of psoriasis pathogenesis. The introduction of tumour necrosis factor (TNF).α and interleukin (IL)-12/-23 inhibitors has resulted in remarkable clinical responses in patients with severe psoriasis and has led to the development of a range of other cytokine modulators currently undergoing investigation. More recently, research in keratinocyte biology and immune cell function, particularly intracellular signalling, has afforded additional opportunities to develop a range of small-molecule oral preparations that may prove effective in disease control. This paper reviews current and emerging systemic treatments in the management of psoriasis.

Using mice to unveil the genetics of cancer resistance

In the UK, four in ten people will develop some form of cancer during their lifetime, with an individual's relative risk depending on many factors, including age, lifestyle and genetic make-up. Much research has gone into identifying the genes that are mutated in tumorigenesis with the overwhelming majority of genetically-modified (GM) mice in cancer research showing accelerated tumorigenesis or recapitulating key aspects of the tumorigenic process. Yet if six out of ten people will not develop some form of cancer during their lifetime, together with the fact that some cancer patients experience spontaneous regression/remission, it suggests there are ways of 'resisting' cancer. Indeed, there are wildtype, spontaneously-arising mutants and GM mice that show some form of 'resistance' to cancer. Identification of mice with increased resistance to cancer is a novel aspect of cancer research that is important in terms of providing both chemopreventative and therapeutic options. In this review we describe the different mouse lines that display a 'cancer resistance' phenotype and discuss the molecular basis of their resistance.

Briakinumab for the treatment of plaque psoriasis

Psoriasis is a chronic inflammatory skin disorder affecting approximately 2% of individuals worldwide. An improved understanding of the pathogenesis of psoriasis has led to the development of targeted biologic therapies. Briakinumab (ABT-874) is a recombinant human antibody that blocks the biological activity of the cytokines interleukin (IL)-12 and IL-23 through their shared subunit p40. IL-12 and IL-23 are key mediators in T-cell differentiation and have been shown to play a significant role in maintaining inflammation and abnormal keratinocyte function in psoriasis patients through development and stimulation of Th1 and Th17 subsets, respectively. In one phase II and four phase III studies (including two 52-week trials), the Psoriasis Area and Severity Index (PASI)-75 score at weeks 12 and 52 was achieved by at least 80.6% and 66.2% (p < 0.001) of patients receiving more than one dose of briakinumab every 4 weeks, respectively, with high proportions of patients achieving PASI-90 and PASI-100 scores (at least 55.4% and 28.8%, respectively; p < 0.001). These studies indicate safety and tolerance of briakinumab therapy for patients with moderate-to-severe chronic plaque psoriasis. In one clinical trial, therapy was associated with increased incidence of major cardiac events. Available results from two briakinumab trials show its positive impact on health-related quality of life. However, the manufacturer has now withdrawn the application in the EU and US.

Identification of allele-specific alternative mRNA processing via transcriptome sequencing

Establishing the functional roles of genetic variants remains a significant challenge in the post-genomic era. Here, we present a method, allele-specific alternative mRNA processing (ASARP), to identify genetically influenced mRNA processing events using transcriptome sequencing (RNA-Seq) data. The method examines RNA-Seq data at both single-nucleotide and whole-gene/isoform levels to identify allele-specific expression (ASE) and existence of allele-specific regulation of mRNA processing. We applied the methods to data obtained from the human glioblastoma cell line U87MG and primary breast cancer tissues and found that 26–45% of all genes with sufficient read coverage demonstrated ASE, with significant overlap between the two cell types. Our methods predicted potential mechanisms underlying ASE due to regulations affecting either whole-gene-level expression or alternative mRNA processing, including alternative splicing, alternative polyadenylation and alternative transcriptional initiation. Allele-specific alternative splicing and alternative polyadenylation may explain ASE in hundreds of genes in each cell type. Reporter studies following these predictions identified the causal single nucleotide variants (SNVs) for several allele-specific alternative splicing events. Finally, many genes identified in our study were also reported as disease/phenotype-associated genes in genome-wide association studies. Future applications of our approach may provide ample insights for a better understanding of the genetic basis of gene regulation underlying phenotypic diversity and disease mechanisms.

The position of the AUG start codon in MFG-based γ-retroviral vectors has a dramatic effect on translation-dependent protein expression

BACKGROUND

In the past three decades, much advancement has been made in γ-retroviral vector mediated gene transfer. One widely used vector design is based on the MFG vector, which uses the Moloney murine leukemia virus (MoMLV) transcriptional unit with extended packaging signals and insertion of the native MoMLV envelope splice acceptor region immediate 5' to the gene of interest inserted at an NcoI restriction site, which contains a translation start codon. Little is known about the impact of variations in start codon location within MFG-based vectors on protein expression.

METHODS

To evaluate variation in start condo placement, a gene encoding a T-cell receptor (TCR) was cloned into an MFG-based vector and site-directed mutagenesis was used to move the gene away from the splice acceptor, as well as alter the frame with respect to the upstream start codon. Kozak consensus sequences were also added to the gene in an attempt to improve translation.

RESULTS

Protein expression as measured by TCR surface expression and biological activity was substantially reduced when the gene was placed downstream and out-of-frame with the NcoI start codon. Expression was reestablished by mutation of the upstream start site, although at a reduced level. These findings were repeated with two other genes, a dominant negative TGFβRII and the reporter protein dEGFP.

CONCLUSIONS

These finding emphasize the scanning rule for translation initiation and stress the importance of cloning genes of interest into or near the native NcoI start site of MFG-based retroviral vectors.

Acquired STAT4 deficiency as a consequence of cancer chemotherapy

Signal Transducer and Activator of Transcription 4 (STAT4) is a transcription factor that is activated by IL-12 signaling and promotes Th1-cell differentiation and IFN-γ production. Defective IFN-γ production because of STAT4 mRNA and protein deficiency occurs after autologous stem cell transplantation for lymphoma. In the present study, we investigated the mechanisms of STAT4 deficiency in lymphoma patients. The tumor-bearing state is not responsible, because STAT4 levels were not significantly different in PBMCs obtained from healthy control subjects compared with those from lymphoma patients before treatment. STAT4 protein levels were significantly decreased in PBMCs and T cells obtained from lymphoma patients after standard-dose chemotherapy. Furthermore, treatment of control PBMC cultures or a natural killer cell line with chemotherapy drugs in vitro also resulted in reduced STAT4 protein and diminished, IL-12-induced IFN-γ production. Translation of STAT4 protein was not impaired in chemotherapy-treated cells, whereas the STAT4 protein half-life was significantly reduced. Chemotherapy drugs promoted the ubiquitination and proteasomal degradation of STAT4. Treatment with the proteasome inhibitor bortezomib reversed chemotherapy-induced STAT4 deficiency and defective IFN-γ production. We conclude that acquired STAT4 deficiency in lymphoma patients is a consequence of treatment with chemotherapy, results that have important implications for the design of optimal immunotherapy for lymphoma.

Green tea prevents non-melanoma skin cancer by enhancing DNA repair

Excessive exposure of the skin to solar ultraviolet (UV) radiation is one of the major factors for the development of skin cancers, including non-melanoma. For the last several centuries the consumption of dietary phytochemicals has been linked to numerous health benefits including the photoprotection of the skin. Green tea has been consumed as a popular beverage world-wide and skin photoprotection by green tea polyphenols (GTPs) has been widely investigated. In this article, we have discussed the recent investigations and mechanistic studies which define the potential efficacy of GTPs on the prevention of non-melanoma skin cancer. UV-induced DNA damage, particularly the formation of cyclobutane pyrimidine dimers, has been implicated in immunosuppression and initiation of skin cancer. Topical application or oral administration of green tea through drinking water of mice prevents UVB-induced skin tumor development, and this prevention is mediated, at least in part, through rapid repair of DNA. The DNA repair by GTPs is mediated through the induction of interleukin (IL)-12 which has been shown to have DNA repair ability. The new mechanistic investigations support and explain the anti-photocarcinogenic activity, in particular anti-non-melanoma skin cancer, of green tea and explain the benefits of green tea for human health.

New interleukin-23 pathway inhibitors in dermatology: ustekinumab, briakinumab, and secukinumab

Interleukin (IL)-23 is an important regulator of T helper-17 lymphocytes, which influence the cutaneous immune system by production of IL-17 and several other proinflammatory cytokines. This pathway has been recently linked to the pathogenesis of psoriasis and numerous other skin diseases. A newly developed biologic drug, ustekinumab (CNTO-1275), which targets the p40 subunit of IL-12 and IL-23, was approved by the US FDA and the European Medicines Agency in 2009 for the treatment of moderate to severe psoriasis. Administered as subcutaneous injections of 45 mg at weeks 0 and 4, and then every 12 weeks, ustekinumab produces a 75% improvement in the Psoriasis Area and Severity Index (PASI) in 66.4-75.7% of patients and a Dermatology Life Quality Index (DLQI) score of 0 or 1 in 55-56% of patients after 12 weeks of therapy. A recent clinical trial also indicates the possible efficacy of ustekinumab in psoriatic arthritis. The proportion of patients who had at least one adverse event through 12 weeks in clinical studies was 51.6-57.6% in the ustekinumab group and 50.4% in the placebo group. Serious adverse events were observed in 1.4-1.6% of patients treated with ustekinumab and in 1.4% of patients receiving placebo. Injection-site reactions occurred in 1-2% of patients and 5% of patients developed anti-ustekinumab antibodies. Further studies are needed to evaluate the long-term efficacy and safety of ustekinumab. Another biologic drug that targets the same molecules, briakinumab (ABT-874), has recently had its approval application withdrawn in the US and Europe to conduct further analysis and clinical trials. The company plans resubmission at a later date. Other IL-23 pathway inhibitors in the pipeline include anti-p19 monoclonal antibody and apilimod (STA-5326), which interfere with IL-23 activity, as well as secukinumab (AIN-457), LY-2439821, and AMG-827, which exhibit their activity at other targets of the IL-23 pathway.

Proanthocyanidins inhibit UV-induced immunosuppression through IL-12-dependent stimulation of CD8+ effector T cells and inactivation of CD4+ T cells

The inhibition of UVB-induced immunosuppression by dietary grape seed proanthocyanidins (GSP) has been associated with the induction of interleukin (IL)-12 in mice, and we now confirm that GSPs do not inhibit UVB-induced immunosuppression in IL-12p40 knockout (IL-12 KO) mice and that treatment of these mice with recombinant IL-12 restores the inhibitory effect. To characterize the cell population responsible for the GSP-mediated inhibition of UVB-induced immunosuppression and the role of IL-12 in this process, we used an adoptive transfer approach. Splenocytes and draining lymph nodes were harvested from mice that had been administered dietary GSPs (0.5%-1.0%, w/w), exposed to UVB, and sensitized by the application of 2,4-dinitrofluorobenzene (DNFB) onto the UVB-exposed skin. CD8(+) and CD4(+) T cells were positively selected and transferred into naive mice that were subsequently challenged by application of DNFB on the ear skin. Naive recipients that received CD8(+) T cells from GSP-treated, UVB-irradiated donors exhibited full contact hypersensitivity (CHS) response. Naive mice that received CD4(+) suppressor T cells from GSP-treated, UVB-exposed mice could mount a CHS response after sensitization and subsequent challenge with DNFB. On culture, the CD8(+) T cells from GSP-treated, UVB-exposed mice secreted higher levels (5- to 8-fold) of Th1 cytokines than CD8(+) T cells from UVB-irradiated mice not treated with GSPs. CD4(+) T cells from GSP-treated, UVB-exposed mice secreted significantly lower levels (80%-100%) of Th2 cytokines than CD4(+) T cells from UVB-exposed mice not treated with GSPs. These data suggest that GSPs inhibit UVB-induced immunosuppression by stimulating CD8(+) effector T cells and diminishing regulatory CD4(+) T cells.

Phase-I clinical trial of IL-12 plasmid/lipopolymer complexes for the treatment of recurrent ovarian cancer

A phase-I trial to assess the safety and tolerability of human interleukin-12 (IL-12) plasmid (phIL-12) formulated with a synthetic lipopolymer, polyethyleneglycol-polyethyleneimine-cholesterol (PPC), was conducted on women with chemotherapy-resistant recurrent ovarian cancer. A total of 13 patients were enrolled in four dose-escalating cohorts and treated with 0.6, 3, 12 or 24 mg m(-2) of the formulated plasmid once every week for 4 weeks. Administration of phIL-12/PPC was generally safe and well-tolerated. Common side effects included low-grade fever and abdominal pain. Stable disease and reduction in serum CA-125 levels were clinically observed in some patients. Measurable levels of IL-12 plasmid were detectable in PF samples collected throughout the course of phIL-12/PPC treatment. In comparison, serum samples either did not contain detectable amounts of plasmid DNA or contained <1% of the amount found in the corresponding PF samples. Treatment-related increases in IFN-gamma levels were observed in PF but not in serum. These data demonstrate that IL-12 gene delivery with a synthetic delivery system is feasible for ovarian cancer patients.

Treatment of disseminated ovarian cancer using nonviral interleukin-12 gene therapy delivered intraperitoneally

BACKGROUND

The poor prognosis associated with ovarian cancer is primarily the result of delayed diagnosis and the lack of an effective treatment for advanced disease. Use of novel immunotherapy strategies are being evaluated that work to enhance local and systemic immune responses against cancer cells and can possibly work together with traditional cytotoxic chemotherapy regimens to produce more effective treatment options.

METHODS

In the present study, we describe a gene-based therapy whereby the anticancer cytokine interleukin-12 gene (pmIL-12) is formulated with a synthetic polymeric delivery vehicle (PPC) and administered intraperitoneally into a mouse model of disseminated ovarian cancer.

RESULTS

The administration of pmIL-12/PPC in tumor-bearing mice was associated with a shift towards a Th1 immune state, including significant increases in murine IL-12 (mIL-12) and interferon (IFN)-gamma (mIFN-gamma) in ascites fluid, with little change in systemic levels of these proteins. The mIL-12 protein was detectable for several days and could be reintroduced with subsequent injections. We show that treatment delayed the onset of ascites formation and improved survival in a dose-dependent manner. A significant decrease in vascular endothelial growth factor was associated with pmIL-12/PPC delivery and believed to play a predominant role in inhibiting ascites accumulation. Administration of pmIL-12/PPC was associated with minimal toxicity and, when combined with standard chemotherapies, resulted in additive improvement in survival.

CONCLUSIONS

Taken together, these results suggest that pmIL-12/PPC may be an effective strategy for inhibiting progression of disseminated ovarian cancer and may offer a new option for treatment of advanced disease that can be used to complement standard therapies.

IL-12 deficiency suppresses 12-O-tetradecanoylphorbol-13-acetate-induced skin tumor development in 7,12-dimethylbenz(a)anthracene-initiated mouse skin through inhibition of inflammation

Interleukin (IL)-12 deficiency exacerbates tumorigenesis in ultraviolet (UV) radiation-induced skin. Here, we assessed the effects of IL-12 deficiency on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced tumor promotion in 7,12-dimethylbenz(a)anthracene (DMBA)-initiated mouse skin. Using this two-stage chemical carcinogenesis protocol, we found that the development of DMBA/TPA-induced skin tumors was diminished in IL-12p40-knockout mice than in their wild-type counterparts. At the termination of the experiment (at 24 weeks), the skin tumor incidence and tumor multiplicity were significantly lower (P < 0.005) in interleukin-12-knockout (IL-12 KO) mice than in their wild-type counterparts, as was the malignant transformation of DMBA/TPA-induced papillomas to carcinomas (P < 0.01). Analysis of samples collected at the termination of the experiments for biomarkers of inflammation by immunohistochemical analysis, western blotting, enzyme-linked immunosorbent assay and real-time polymerase chain reaction revealed significantly lower levels of cyclooxygenase-2 (COX-2), prostaglandin (PG) E(2), proliferating cell nuclear antigen, cyclin D1 and the proinflammatory cytokines (tumor necrosis factor-alpha, IL-1beta and IL-6) in the DMBA/TPA-treated tumors and tumor-uninvolved skin of IL-12 KO mice than the skin and tumors of DMBA/TPA-treated wild-type mice. Analysis of the skin 6 h after TPA treatment showed that the TPA-induced promotion of skin edema, inflammatory leukocyte infiltration, COX-2 expression and PGE(2) production was significantly lower in the skin of the IL-12-KO mice than their wild-type counterparts. These results indicate that DMBA/TPA-induced skin tumor development differs from UVB-induced skin tumor development in that endogenous IL-12 acts to inhibit UVB-induced skin tumor development and malignant progression of the skin tumors to carcinoma. In the case of DMBA/TPA-induced skin tumor development, the endogenous IL-12 modulates the tumor promoter stimulation of inflammatory responses.

Post-Chemotherapeutic Administration of Interleukin-12 Retards Tumor Growth and Enhances Immune Cell Function: Combination Therapy Using Paclitaxel and IL-12

The antineoplastic agent paclitaxel (TAXOL) is a potent inhibitor of tumor cell division that also suppresses lymphocyte proliferative responses. Because chemotherapy-induced immunosuppression may limit the patient's antitumor responses, we investigated the possibility that the T cell stimulatory cytokine interleukin-12 (IL-12) could be used to reverse paclitaxel-mediated lymphocyte suppression. Recognizing that IL-12 treatment following paclitaxel exposure promotes T cell responses in vitro, we evaluated the antitumor efficacy of IL-12 administration concurrent and subsequent to paclitaxel treatment. Simultaneous administration of IL-12 and paclitaxel failed to limit tumor outgrowth or extend survival beyond chemotherapy alone, although IL-12 did not manifest negative effects. In contrast, post-chemotherapeutic IL-12 significantly delayed tumor outgrowth and extended survival in tumor-burdened BALB/c mice. Correlative enhancements in ex vivo immune cell effector function were also observed following paclitaxel and temporally delayed IL-12 therapy. Collectively, these data demonstrate an immunotherapeutic efficacy of IL-12 that augments the chemotherapeutic activities of paclitaxel when delivered in the appropriate temporal sequence.

Polysaccharide-protein complex from Lycium barbarum L. is a novel stimulus of dendritic cell immunogenicity

Dendritic cell (DC) immunogenicity correlates with its maturation, which can be induced by toxic microbial products such as LPS. In this study, we report that a nontoxic polysaccharide-protein complex isolated from a Chinese medicinal herb, Lycium barbarum (LBP), induces phenotypic and functional maturation of DCs with strong immunogenicity. LBP up-regulated DC expression of CD40, CD80, CD86, and MHC class II molecules; down-regulated DC uptake of Ag; enhanced DC allostimulatory activity; and induced IL-12p40 and p70 production. All of its five fractions were active. LBP developed enhanced Th1 response, and LBP-treated DCs enhanced Th1 and Th2 responses in vitro and in vivo. Our study provides evidence and rationale on using LBP in various clinical conditions to enhance host immunity and suggests LBP as a potent adjuvant for the design of DC-based vaccines.

New biologics for psoriasis and psoriatic arthritis

The prevalence of psoriasis is estimated to be 2.2% in the United States, and 6-39% of patients with psoriasis also develop psoriatic arthritis. New advances have been made in developing treatment options. A new human tumor necrosis factor (TNF)-alpha antibody, golimumab, has been shown to significantly improve symptoms of psoriatic arthritis. In addition, clinical trials of certolizumab pegol, a PEGylated Fab' fragment of an anti-TNF-alpha monoclonal antibody, show promising results for treating rheumatoid arthritis and suggest that it may be applicable for treating psoriasis and psoriatic arthritis in the future. New biologic therapies also include antibodies to interleukin-12 and interleukin-23. Phase II studies suggest that ustekinumab is effective in alleviating symptoms of psoriasis and psoriatic arthritis. However, longer studies with radiographic evaluation will be required before their impact on joint destruction can be assessed.

Inhibition of UVB-induced skin tumor development by drinking green tea polyphenols is mediated through DNA repair and subsequent inhibition of inflammation

Consumption of green tea polyphenols (GTPs) in drinking water prevents photocarcinogenesis in mice; however, the molecular mechanisms underlying this effect have not been fully elucidated. Using IL-12p40 knockout (KO) mice and their wild-type counterparts and an established photocarcinogenesis protocol, we found that although administration of GTPs (0.2%, w/v) in drinking water significantly reduced UVB-induced tumor development in wild-type mice, this treatment had a nonsignificant effect in IL-12-KO mice. GTPs resulted in reduction in the levels of markers of inflammation (cyclooxygenase-2, prostaglandin E(2), proliferating cell nuclear antigen, and cyclin D1) and proinflammatory cytokines (tumor necrosis factor-alpha, IL-6, and IL-1beta) in chronically UVB-exposed skin and skin tumors of wild-type mice but less effective in IL-12p40-KO mice. UVB-induced DNA damage (cyclobutane pyrimidine dimers) was resolved rapidly in GTPs-treated wild-type mice than untreated wild-type mice and this resolution followed the same time course as the GTPs-induced reduction in the levels of inflammatory responses. This effect of GTPs was less pronounced in IL-12-KO mice. The above results were confirmed by treatment of IL-12-KO mice with murine recombinant IL-12 and treatment of wild-type mice with neutralizing anti-IL-12 antibody. To our knowledge, it is previously unreported that prevention of photocarcinogenesis by GTPs is mediated through IL-12-dependent DNA repair and a subsequent reduction in skin inflammation.

IL-12 deficiency exacerbates inflammatory responses in UV-irradiated skin and skin tumors

IL-12 deficiency has been shown to promote photocarcinogenesis in mice. As UVB-induced inflammation is an important tumor-promoting event in the development of skin tumors, we determined the effects of IL-12-deficiency on UVB-induced inflammatory responses in mice. For this purpose, IL-12-knockout (IL-12 KO) and their wild-type counterparts were subjected to a photocarcinogenesis protocol; skin and tumor samples were collected at the termination of the experiment, and analyzed for biomarkers of inflammation and their mediators. We found that the levels of infiltrating leukocytes, myeloperoxidase, proliferating cell-nuclear antigen (PCNA), COX-2, PGE2, and the proinflammatory cytokines IL-1beta, TNF-alpha, and IL-6 were higher in the UVB-exposed skin of IL-12 KO than in that of wild-type mice. In a short-term experiment, pretreatment of IL-12 KO mice with rIL-12 (50 ng per mouse) before each exposure to UVB increased the repair rate of UVB-induced cyclobutane pyrimidine dimers, while inhibiting UVB-induced increases in myeloperoxidase, COX-2, PGE2, PCNA, TNF-alpha, and IL-1beta in the skin as compared with non-rIL-12-treated IL-12 KO mice. Similarly, tumors of IL-12 KO mice expressed higher levels of inflammatory responses than those of wild-type mice. Together, our data suggest that IL-12 KO mice are more susceptible to both UVB-induced inflammation and photocarcinogenesis because of the deficiency in the repair of UVB-induced DNA damage.

Update on the natural history and systemic treatment of psoriasis

The onset of psoriatic disease and its associated comorbidities involves the interplay among a myriad of genetic and environmental risk factors. As we gain further insight into the immunopathogenesis of psoriasis, we hope it will provide the basis for the development of safer, more efficacious, and more durable therapeutics in the future. Given its enormous toll on patient health and quality of life, steps should be taken to prevent or decrease the risk for psoriasis-associated comorbidities through behavior modification and use of preventative health screenings and treatments. Future studies will need to be performed to determine if successful treatment of psoriasis will lead to a decreased risk for developing psoriasis-associated comorbidities over time.

Interleukin-12, interleukin-23, and psoriasis: Current prospects

The clinical phenotype of psoriasis results from infiltration of T cells in the skin and elaboration of inflammatory cytokines. Interleukin (IL)-12 and, more recently, IL-23 have been implicated in the pathogenesis of psoriatic lesions. New therapies, including a monoclonal antibody against a subunit shared by IL-12 and IL-23, have been developed to treat psoriasis. Our purpose was to review the literature on IL-12 and IL-23 as a basis for understanding the use of anti-IL-12/IL-23 therapy for psoriasis. A review of English-language articles was performed using PubMed to identify articles pertaining to IL-12, IL-23, and psoriasis. IL-12 and IL-23 share a common subunit (p40) and have a distinct subunit (p35 and p19, respectively). Transgenic mice that overexpress IL-12 p40 develop inflammatory skin lesions. Both IL-12 knockout mice, which are deficient in IL-12, and human beings with a genetic IL-12 deficiency show increased susceptibility to intracellular pathogens and defective delayed-type hypersensitivity responses. These genetic deficiency states suggest the potential for adverse side effects from clinical administration of anti IL-12 p40 therapy. IL-12 p40 antibody was well tolerated in a phase I clinical trial with few adverse events and substantial improvements in psoriasis in most individuals. There was dose-dependent efficacy and substantial improvement in a larger cohort of patients in a phase II clinical trial. Larger and longer trials of anti IL-12/IL-23 therapies are needed to assess their clinical use and potential for infection and other adverse events.

Interleukin-12 deficiency is permissive for angiogenesis in UV radiation-induced skin tumors

We have shown previously that endogenous deficiency of interleukin (IL)-12 promotes photocarcinogenesis in mice. To characterize the role of IL-12 deficiency in tumor angiogenesis, we developed IL-12p35 knockout (IL-12 KO) mice on a C3H/HeN background. IL-12 KO mice and their wild-type (WT) counterparts were subjected to a photocarcinogenesis protocol. When tumor yield was stabilized, samples of tumor and tumor-uninvolved UVB-exposed skin were collected and subjected to immunohistochemistry, gelatinolytic zymography, real-time PCR, and Western blot analysis of angiogenic factors. We found that the protein, mRNA expression and/or activity of the matrix metalloproteinases (MMP)-2, MMP-3, MMP-7, and MMP-9, and basic fibroblast growth factor, which play crucial roles in tumor growth, were significantly higher in UVB-exposed skin and tumors of IL-12 KO mice compared with WT mice. With respect to the tumor vasculature, the expression of CD31-positive cells and the expression of vascular endothelial growth factor were higher in the tumors of IL-12 KO mice than WTs. The proliferative capacity of tumor cells of the IL-12 KO mice was significantly higher than their WT counterparts when determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and by analyzing the expression of cyclin D1. The level of the proinflammatory cytokine IL-6 and the expression of IL-23 in tumors of IL-12 KO mice were markedly higher than in the tumors of WT mice. IL-23 has been shown to promote tumor growth. Together, these data indicate for the first time that IL-12 deficiency promotes proangiogenic stimuli in UVB-induced skin tumors and suggest that endogenous enhancement of IL-12 levels may be effective in the prevention and treatment of UV-induced skin cancers.