Transfection of IL-2 and/or IL-12 genes into spleen in treatment of rat liver cancer

Interleukin-12 induces IFN-γ secretion and STAT signaling implying its potential regulation of Th1 cell response in Nile tilapia

As a pleiotropic cytokine consisting of IL-12p35 and IL-12p40, Interleukin-12 (IL-12) features in inflammation regulation and anti-bacterial immunity. While IL-12 homologs have been identified in non-mammalian species, the precise mechanisms by which IL-12 contributes to early adaptive immune responses in vertebrates remain incompletely understood. Herein, an evolutionary conserved Oreochromis niloticus IL-12 (defined as OnIL-12) was identified by synteny characterization, structural comparisons and phylogenetic pattern of IL-12p35b and IL-12p40a. IL-12p35b and IL-12p40a exhibited widespread expression in lymphoid-related tissues of tilapia, while their mRNA expression in head-kidney demonstrated a significant increase after Edwardsiella piscicida infection. Compared with other lymphocytes, recombinant OnIL-12 (rOnIL-12) displayed stronger affinity binding to T cells. Although stimulation of lymphocytes with the p35b or p40a subunit resulted in a significant induction of IFN-γ expression, rOnIL-12 showed stronger potential to promote IFN-γ expression than these subunits. rOnIL-12 not only elevated the mRNA expression level Th1 cell-associated transcription factor T-bet in lymphocytes, but also increased the proportion of CD4-1+IFN-γ+ lymphocytes. Moreover, the mRNA and phosphorylation levels of STAT1, STAT3, STAT4 and STAT5 were enhanced by rOnIL-12. These findings will offer previous evidence for further exploration into the regulatory mechanisms of Th1 cellular immunity in early vertebrates.

Dynamics of the spleen and its significance in a murine H22 orthotopic hepatoma model

The dynamics of the spleen during tumor progression remains incompletely understood. In this study, we established a murine H22 orthotopic hepatoma model and dynamically detected alterations in the percentages of immunocytes in the spleen. We observed a prominent myeloid-derived suppressor cell (MDSC) accumulation during the early response which persisted through all the stages of tumor growth. In addition, the percentage of regulatory T cells (Tregs) increased by week 2. Although the percentage of CD3(+)CD49b(+) natural killer T (NKT) cells increased by day 3, and that of CD3(+)CD4(+) T cells slightly increased by week 1, they decreased to either normal or lower levels compared with those of normal mice. The percentages of total CD3(+), CD3(+)CD4(+), and CD3(+)CD8(+) T cells decreased by week 2, and that of NK cells decreased by week 3. The activation of non-Treg CD4(+) T cells was scarce. Moreover, splenic MDSCs of tumor-bearing mice suppressed the activation of splenocytes. Therefore, a negative immune response gradually prevailed over a positive immune response during tumor growth. In addition, splenectomy was performed at the time of tumor inoculation, and we found that splenectomy could prolong the survival time, reduce the tumor weights, decrease the ascites volumes, and ameliorate the immune status of the tumor-bearing mice. Splenectomy also decreased the percentage of MDSCs and increased the percentages of CD8(+) T cells, NK, and NKT cells in tumor tissues. Additionally, splenectomy decreased the percentage of MDSCs and increased that of CD8(+) T cells in peripheral blood. Overall, our findings suggest that immune-negative cells are dominant in the spleen during tumor progression. Splenectomy could be helpful to improve the immune responses of tumor-bearing hosts.

Potential immunotherapeutic role of interleukin-2 and interleukin-12 combination in patients with hepatocellular carcinoma

Background

Many recent therapeutic interventions are necessary to improve the treatment of hepatocellular carcinoma (HCC), including immunotherapy, which seems to offer one of the new realistic therapeutic modalities. This study aims to investigate the optimization of immunotherapy for HCC patients by appraisal of both interferon (IFN)-γ levels and phenotyping of lymphocytes obtained from peripheral blood and fine-needle aspirates.

Methods

The isolated lymphocytes were cultured in the presence of interleukins (IL)-2, IL-4, and IL-12. Enzyme-linked immunosorbent assay and flow cytometric techniques were used for the assessment of human IFN-γ production and the studied T-cell subpopulations, respectively.

Results

Mixed cell populations of peripheral blood lymphocytes and tumor infiltrating lymphocytes treated with IL-2 plus IL-12 showed a marked and significant elevation in IFN-γ levels in their culture media, a significant decrease in the percentage of cluster of differentiation (CD)4⁺CD25⁺ regulatory T-cells, and a nonsignificant increase in the percentage of CD8⁺ cytotoxic T-cells. Meanwhile, IL-2 plus IL-4 treatment demonstrated nonsignificant effects.

Conclusion

Our data suggested that IL-12 together with IL-2 caused a suppression of CD4⁺CD25⁺ regulatory T-cells and an elevation of IFN-γ levels, which play a crucial immunotherapeutic role in the management of HCC patients.

Associations between polymorphisms in IL-12A, IL-12B, IL-12Rβ1, IL-27 gene and serum levels of IL-12p40, IL-27p28 with esophageal cancer

PURPOSE

The aim of this study was to investigate whether IL-12A, IL-12B, IL-12Rβ1, and IL-27 gene polymorphisms and serum levels of IL-12, IL-27 are associated with esophageal cancer.

METHODS

We genotyped IL-12A gene rs568408, IL-12B gene rs3212227, IL-12Rβ1 gene 378 C/G, IL-27 gene rs153109, rs17855750, and rs181206 polymorphisms in a case-control study of 426 esophageal cancer patients and 432 health controls, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and serum IL-12p40 and IL-27p28 levels were measured by enzyme-linked immunosorbent assay.

RESULTS

Both serum IL-12p40 and IL-27p28 levels were significantly higher in controls than those in patients (P < 0.01). Rs568408 AG/AA, rs3212227 CC/AC, and IL-12Rβ1 378 GG/GC genotypes were associated with significantly increased risk of esophageal cancer (rs568408: χ(2) = 5.704, P = 0.017; rs3212227: χ(2) = 7.689, P = 0.006; IL-12Rβ1 378C/G: χ(2) = 5.206, P = 0.023). Moreover, rs3212227 CC/AC and 378 GG/GC genotypes were observed significantly associated with decreased serum IL-12p40 level in patients compare to other genotypes (rs3212227: t = 2.129, P = 0.034; IL-12Rβ1 378 C/G: t = 2.178, P = 0.030). Furthermore, frequency of rs3212227 CC/AC genotypes was significantly higher in patients with poor differentiation than those with AA genotype (χ(2) = 4.314, P = 0.035).

CONCLUSION

Our data suggest that the impaired production of IL-12p40 and IL-27p28 behaves as risk factors for esophageal cancer occurrence. IL-12B gene rs3212227 CC/AC and IL-12Rβ1 gene 378 GG/GC genotypes, which associated with decreased IL-12p40 level, may contribute to esophageal cancer susceptibility.

Association of single nucleotide polymorphisms in IL-12 and IL-27 genes with colorectal cancer risk

OBJECTIVES

Interleukin-12 (IL-12) plays an important role in antitumor immunity. Interleukin-27 (IL-27) is a novel IL-12 family member. The present studies demonstrate that IL-27 mediates potent antitumor activity. However, No studies have examined the association of these polymorphism with colorectal cancer (CRC). Therefore, we investigated the relationship of IL-12 and IL-27 gene polymorphisms and CRC.

DESIGN AND METHODS

We analyzed polymorphisms of IL-12 gene 16974 A/C and IL-27 gene -964 A/G, 2905 T/G, 4730 T/C in 410 patients with CRC and 450 controls, using PCR-RFLP method.

RESULTS

There were no significant differences in the genotype and allele frequencies of IL-12 and IL-27 gene polymorphisms between the group of patients with CRC and the controls. Furthermore, no association was found between IL-12 family gene polymorphisms and different clinical stages in patients with CRC.

CONCLUSION

These findings suggest that IL-12 and IL-27 gene polymorphisms may not be involved in susceptibility to CRC.

Evaluating vaccinia virus cytokine co-expression in TLR GKO mice

Using Toll-like receptor (TLR) and MyD88 gene knock-out (GKO) mice the effect of TLRs and MyD88 on virus replication, interferon (IFN)-β production, natural killer (NK) cell and CD8T cell responses were assessed following ectromelia virus (ECTV) and recombinant vaccinia virus (rVV) infection. The capacity for rVVs encoding cytokines to restore immune function in MyD88(-/-) mice was clearly demonstrated. Results showed that TLR2(-/-), TLR4(-/-)and TLR7(-/-) mice survived ECTV infection whereas MyD88(-/-) and TLR9(-/-)mice, in contrast, were highly susceptible. Next, following infection with rVV, MyD88(-/-) mice elicited reduced serum IFN-β, NK cell and CD8T cell responses compared with wild-type mice, whereas TLR9(-/-) mice showed elevated CD8T cell responses. When MyD88(-/-)mice were infected with rVV co-expressing IFN-β these mice were able to restore IFN-β levels and CD8T cell responses but not NK cell activation. Interestingly, even though rVV co-expressing interleukin (IL)-2 enhanced NK cell activation in MyD88(-/-) mice, this was not associated with an antiviral effect, as observed in normal mice. Surprisingly, co-infection with rVV IL-2/rVV IL-12, but not rVV IL-2/rVV IFN-β, restored the attenuated phenotype of rVV IL-2 in MyD88(-/-) mice indicating that the IL-2/IL-12 combination promotes antiviral responses. Our results clearly show that the CD8T cell defect observed in MyD88(-/-) mice to vaccinia virus infection can be restored by rVV-encoding IFN-β demonstrating the critical role of this cytokine in T cell mediated immunity and illustrates that the model can provide an effective platform for the elucidation of cytokine immunobiology.

A novel functional polymorphism, 16974 A/C, in the interleukin-12-3' untranslated region is associated with risk of glioma

Genetic factors are important in the development of glioma. Interleukin-12 (IL-12) is a multifunctional cytokine that induces Interferon (IFN)-gamma secretion and plays an important role in antitumor immunity. Interleukin-27 (IL-27) is a novel IL-12 family member, and the present studies demonstrate that IL-27 mediates a potent antitumor activity. The aim of this study was to investigate whether IL-12 and IL-27 gene polymorphisms and their serum levels are associated with glioma. We analyzed IL-12 gene 16974 A/C and IL-27 gene -964 A/G, 2905 T/G, and 4730 T/C polymorphisms in 210 patients with glioma and 220 matched controls, using polymerase chain reaction-restriction fragment length polymorphism method and DNA sequencing methods, while serum IL-12p40 and IL-27p28 levels were measured by enzyme-linked immunosorbent assay. Serum IL-12p40 and IL-27p28 levels were decreased in patients with glioma compared with controls (p < 0.01). There were significant differences in the genotype and allele frequencies of the IL-12 gene 16974 A/C polymorphism between the group of patients with glioma and the control group (p < 0.05). Moreover, genotypes carrying the IL-12 16974 C variant allele were associated with decreased serum IL-12p40 and IL-27p28 levels compared to the homozygous wild-type genotype in patients with glioma. The IL-12 gene 16974 A/C polymorphism may regulate expression of the serum IL-12p40 and IL-27p28, and associate with increased risk of glioma. Thus, genotypes carrying the IL-12 16974 C variant allele had a decreased ability to produce IL-12 and IL-27, which may contribute to glioma susceptibility.

The regulatory, inflammatory, and T cell programming roles of interleukin-2 (IL-2)

Signaling through IL-2 induces the activation of pathways that lead to the proliferation, survival and cytokine production of effector T cells. However, through negative feedback mechanisms, internalization of the IL-2 receptor, induction of activation-induced cell death, and the generation of regulatory T cells, IL-2 also promotes the suppression of inflammatory responses. In regulatory T cells, IL-2 signaling upregulates the expression of FoxP3. Regulatory T cell induction by TGF-beta also requires IL-2. Additionally, pro-inflammatory and pro-survival pathways involving PI3K upon IL-2 stimulation is inhibited by PTEN in regulatory T cells. Importantly, IL-2 signaling is key for the development, expansion and maintenance of regulatory T cells. However, gamma(c) cytokines can replace requirements for IL-2 in regulatory T cells, although not with the same efficacy. The dual roles of IL-2 in inflammation are demonstrated in that mice deficient in both FoxP3 and IL-2 display less severe symptoms compared to FoxP3 deficient mice. Finally, IL-2 not only plays a key role in the induction of effector T cells and regulatory T cells, it also inhibits IL-17 producing T cells. By understanding complex dynamics of IL-2 interactions in the inflammatory response, therapies may be developed or modified for regulating immune related diseases.

Immunotherapy of cancer by IL-12-based cytokine combinations

Cancer is a multi-faceted disease comprising complex interactions between neoplastic and normal cells. Over the past decade, there has been considerable progress in defining the molecular, cellular and environmental contributions to the pathophysiology of tumor development. Despite these advances, the conventional treatment of patients still generally involves surgery, radiotherapy and/or chemotherapy, and the clinical outcome for many of these efforts remains unsatisfactory. Recent studies have highlighted the feasibility of using immunotherapeutic approaches that seek to enhance host immune responses to developing tumors. These strategies include immunomodulatory cytokines, with TNF-alpha, type I or type II IFNs, IL-2, IL-12, IL-15 and IL-18 being among the most potent inducers of anti-tumor activity in a variety of preclinical studies. More recently, some exciting new cytokines have been characterized, such as IL-21, IL-23, IL-27 and their immunomodulatory and antitumor effects in vitro and in vivo suggest that they may have considerable promise for future immunotherapy protocols. The promise of cytokine therapy does indeed derive from the identification of these novel cytokines but even more fundamentally, the field is greatly benefiting from the ever-expanding amount of preclinical data that convincingly demonstrate synergistic and/or novel biologic effects, which may be achieved through the use of several combinations of cytokines with complementary immune-stimulating capabilities. One cytokine in particular, IL-12, holds considerable promise by virtue of the fact that it plays a central role in regulating both innate and adaptive immune responses, can by itself induce potent anticancer effects, and synergizes with several other cytokines for increased immunoregulatory and antitumor activities. This review discusses the antitumor activity of IL-12, with a special emphasis on its ability to synergize with other cytokines for enhancement of immune effector cell populations and regulation of host-tumor cell interactions and the overall tumor microenvironment.

Gene therapy of liver cancer

The application of gene transfer technologies to the treatment of cancer has led to the development of new experimental approaches like gene directed enzyme/pro-drug therapy (GDEPT), inhibition of oncogenes and restoration of tumor-suppressor genes. In addition, gene therapy has a big impact on other fields like cancer immunotherapy, anti-angiogenic therapy and virotherapy. These strategies are being evaluated for the treatment of primary and metastatic liver cancer and some of them have reached clinical phases. We present a review on the basis and the actual status of gene therapy approaches applied to liver cancer.