The antitumor effects of adenoviral-mediated, intratumoral delivery of interleukin 23 require endogenous IL-12

Localized Interleukin-12 for Cancer Immunotherapy

Interleukin-12 (IL-12) is a potent, pro-inflammatory type 1 cytokine that has long been studied as a potential immunotherapy for cancer. Unfortunately, IL-12's remarkable antitumor efficacy in preclinical models has yet to be replicated in humans. Early clinical trials in the mid-1990's showed that systemic delivery of IL-12 incurred dose-limiting toxicities. Nevertheless, IL-12's pleiotropic activity, i.e., its ability to engage multiple effector mechanisms and reverse tumor-induced immunosuppression, continues to entice cancer researchers. The development of strategies which maximize IL-12 delivery to the tumor microenvironment while minimizing systemic exposure are of increasing interest. Diverse IL-12 delivery systems, from immunocytokine fusions to polymeric nanoparticles, have demonstrated robust antitumor immunity with reduced adverse events in preclinical studies. Several localized IL-12 delivery approaches have recently reached the clinical stage with several more at the precipice of translation. Taken together, localized delivery systems are supporting an IL-12 renaissance which may finally allow this potent cytokine to fulfill its considerable clinical potential. This review begins with a brief historical account of cytokine monotherapies and describes how IL-12 went from promising new cure to ostracized black sheep following multiple on-study deaths. The bulk of this comprehensive review focuses on developments in diverse localized delivery strategies for IL-12-based cancer immunotherapies. Advantages and limitations of different delivery technologies are highlighted. Finally, perspectives on how IL-12-based immunotherapies may be utilized for widespread clinical application in the very near future are offered.

Adenoviral gene transfer of a single-chain IL-23 induces psoriatic arthritis-like symptoms in NOD mice

Previously, we demonstrated that intratumoral delivery of adenoviral vector encoding single-chain (sc)IL-23 (Ad.scIL-23) was able to induce systemic antitumor immunity. Here, we examined the role of IL-23 in diabetes in nonobese diabetic mice. Intravenous delivery of Ad.scIL-23 did not accelerate the onset of hyperglycemia but instead resulted in the development of psoriatic arthritis. Ad.scIL-23-treated mice developed erythema, scales, and thickening of the skin, as well as intervertebral disc degeneration and extensive synovial hypertrophy and loss of articular cartilage in the knees. Immunological analysis revealed activation of conventional T helper type 17 cells and IL-17-producing γδ T cells along with a significant depletion and suppression of T cells in the pancreatic lymph nodes. Furthermore, treatment with anti-IL-17 antibody reduced joint and skin psoriatic arthritis pathologies. Thus, these Ad.scIL-23-treated mice represent a physiologically relevant model of psoriatic arthritis for understanding disease progression and for testing therapeutic approaches.-Flores, R. R., Carbo, L., Kim, E., Van Meter, M., De Padilla, C. M. L., Zhao, J., Colangelo, D., Yousefzadeh, M. J., Angelini, L. A., Zhang, L., Pola, E., Vo, N., Evans, C. H., Gambotto, A., Niedernhofer, L. J., Robbins, P. D. Adenoviral gene transfer of a single-chain IL-23 induces psoriatic arthritis-like symptoms in NOD mice.

Interleukin (IL)-12 and IL-23 and Their Conflicting Roles in Cancer

The balance of proinflammatory cytokines interleukin (IL)-12 and IL-23 plays a key role in shaping the development of antitumor or protumor immunity. In this review, we discuss the role IL-12 and IL-23 plays in tumor biology from preclinical and clinical data. In particular, we discuss the mechanism by which IL-23 promotes tumor growth and metastases and how the IL-12/IL-23 axis of inflammation can be targeted for cancer therapy.

Gene therapy based on interleukin-12 loaded chitosan nanoparticles in a mouse model of fibrosarcoma

OBJECTIVES

Interleukin-12 (IL-12) as a cytokine has been proved to have a critical role in stimulating the immune system and has been used as immunotherapeutic agents in cancer gene therapy. Chitosan as a polymer, with high ability of binding to nucleic acids is a good candidate for gene delivery since it is biodegradable, biocompatible and non-allergenic polysaccharide. The objective of the present study was to investigate the effects of cells transfected with IL-12 loaded chitosan nanoparticles on the regression of fibrosarcoma tumor cells (WEHI-164) in vivo.

MATERIALS AND METHODS

WEHI-164 tumor cells were transfected with IL-12 loaded chitosan nanoparticles and then were injected subcutaneously to inoculate tumor in BALB/c mice. Tumor volumes were determined and subsequently extracted after mice sacrifice. The immunohistochemistry staining was performed for analysis of Ki-67 expression (a tumor proliferation marker) in tumor masses. The expression of IL-12 and IFN-γ were studied using real-time polymerase chain reaction and immunoblotting.

RESULTS

The group treated with IL-12 loaded chitosan nanoparticles indicated decreasing of tumor mass[r1] volume (P<0.001). The results of western blotting and real-time PCR showed that the IL-12 expression was increased in the group. Immunohistochemistry staining indicated that the Ki-67expression was reduced in the group treated with IL-12 loaded chitosan nanoparticles.

CONCLUSION

IL-12 gene therapy using chitosan nanoparticles has therapeutic effects on the regression of tumor masses in fibrosarcoma mouse model.

IL-Y, a synthetic member of the IL-12 cytokine family, suppresses the development of type 1 diabetes in NOD mice

The IL-12 family of heterodimeric cytokines, consisting of IL-12, IL-23, IL-27, and IL-35, has important roles in regulating the immune response. IL-12 family members are comprised of a heterodimer consisting of α and β chains: IL-12 (p40 and p35), IL-23 (p40 and p19), IL-27 (Ebi3 and p28), and IL-35 (Ebi3 and p35). Given the combinatorial nature of the IL-12 family, we generated adenoviral vectors expressing two putative IL-12 family members not yet found naturally, termed IL-X (Ebi3 and p19) and IL-Y (p40 and p28), as single-chain molecules. Single chain IL-Y (scIL-Y), but not scIL-X, was able to stimulate significantly a unique cytokine/chemokine expression profile as well as activate STAT3 in mice, in part, through a pathway involving IL-27Rα in splenocytes. Adenoviral-mediated, intratumoral delivery of scIL-Y increased tumor growth in contrast to the anti-tumor effects of scIL-12 and scIL-23. Similarly, treatment of prediabetic NOD mice by intravenous injection of Ad.scIL-Y prevented the onset of hyperglycemia. Analysis of cells from Ad.scIL-Y-treated NOD mice demonstrated that scIL-Y reduced expression of inflammatory mediators such as IFN-γ. Our data demonstrate that a novel, synthetic member of the IL-12 family, termed IL-Y, confers unique immunosuppressive effects in two different disease models and thus could have therapeutic applications.

New insights into IL-12-mediated tumor suppression

During the past two decades, interleukin-12 (IL-12) has emerged as one of the most potent cytokines in mediating antitumor activity in a variety of preclinical models. Through pleiotropic effects on different immune cells that form the tumor microenvironment, IL-12 establishes a link between innate and adaptive immunity that involves different immune effector cells and cytokines depending on the type of tumor or the affected tissue. The robust antitumor response exerted by IL-12, however, has not yet been successfully translated into the clinics. The majority of clinical trials involving treatment with IL-12 failed to show sustained antitumor responses and were associated to toxic side effects. Here we discuss the therapeutic effects of IL-12 from preclinical to clinical studies, and will highlight promising strategies to take advantage of the antitumor activity of IL-12 while limiting adverse effects.

A balance of interleukin-12 and -23 in cancer

Interleukin (IL)-12 and IL-23 share the IL-12p40 molecule. IL-12 promotes T helper (Th)1 immunity and IL-23 promotes Th17 immunity, and it has recently become apparent that the balance between IL-12 and IL-23 is important in carcinogenesis. A series of studies demonstrated that, where tumor initiation, growth, and metastasis are concerned, IL-12 may act independently of interferon (IFN)-γ, and IL-23 independently of IL-17A. This review explores the activity of IL-23 in carcinogenesis. In the context of the tumor-inhibitory effects of IL-12, and tumor-promoting effects of IL-23, we discuss the use of anti-IL-12p/23 monoclonal antibodies (mAbs) in autoimmune inflammatory disorders and the alternative specific neutralization of IL-23.