Monocytes expression of IL-12 related and IL-10 genes in association with development of colorectal cancer

Signaling pathways underlying TGF-β mediated suppression of IL-12A gene expression in monocytes

Transforming growth factor-β (TGF-β) is a pleiotropic cytokine essential for multiple biological processes, including the regulation of inflammatory and immune responses. One of the important functions of TGF-β is the suppression of the proinflammatory cytokine interleukin-12 (IL-12), which is crucial for mounting an anti-tumorigenic response. Although the regulation of the IL-12p40 subunit (encoded by the IL-12B gene) of IL-12 has been extensively investigated, the knowledge of IL-12p35 (encoded by IL-12A gene) subunit regulation is relatively limited. This study investigates the molecular regulation of IL-12A by TGF-β-activated signaling pathways in THP-1 monocytes. Our study identifies a complex regulation of IL-12A gene expression by TGF-β, which involves multiple cellular signaling pathways, such as Smad2/3, NF-κB, p38 and JNK1/2. Pharmacological inhibition of NF-κB signaling decreased IL-12A expression, while blocking the Smad2/3 signaling pathway by overexpression of Smad7 and inhibiting JNK1/2 signaling with a pharmacological inhibitor, SP600125, increased its expression. The elucidated signaling pathways that regulate IL-12A gene expression potentially provide new therapeutic targets to increase IL-12 levels in the tumor microenvironment.

A role of eosinophils in mediating the anti-tumour effect of cryo-thermal treatment

Previous, we established a novel therapeutic approach to tumour of cryo-thermal therapy, which can induce durable anti-tumour memory immunity mediated by CD4⁺ T cell, and contribute to prolonged survival in B16F10 murine melanoma model and 4T1 murine mammary carcinoma. It has become apparent that innate immune cells are involved in the regulation of adaptive T cell immunity. Our previous studies revealed that cryo-thermal therapy induced M1 macrophage polarization and DCs maturation were required for the shaping of systemic long-lived T cell mediated anti-tumour memory immunity. Eosinophils are multifunctional innate effector cells and there is lack of knowledge on the role of eosinophils in cryo-thermal-induced anti-tumour immunity. This study revealed that cryo-thermal therapy activated eosinophils in spleen at early stage following the treatment. Furthermore, cryo-thermal-activated eosinophils exerted versatile immunologic regulation from innate immunity to anti-tumour adaptive immunity, such as M1 macrophage polarization, DCs maturation, differentiation of CD4-CTL subtypes and enhanced cytotoxicity of CD8⁺ T cells. Our study indicated that the cryo-thermal-activated eosinophils was essential for the shaping of durable anti-tumour memory immunity. Thus, our results present a new concept for eosinophils mediated anti-tumour immunity after cryo-thermal therapy.

Increased transforming growth factor β and interleukin 10 transcripts in peripheral blood mononuclear cells of colorectal cancer patients

Aim of the study

The ability of immune cells in peripheral blood to produce certain cytokines affects tumour-elicited inflammation. The aim of this study was to investigate the gene expression of interleukin 12A (IL-12A), IL-12B, IL-23A, IL-10, IL-6, transforming growth factor β (TGF-β), HDAC3, and iNOS in peripheral blood mononuclear cells (PBMC) from colorectal cancer (CRC) patients.

Material and methods

The venous blood for PBMC isolation was collected preoperatively and 10 days after surgery, from CRC patients. After isolation of total RNA and synthesis of cDNA, quantitative real-time PCR assays were performed.

Results

Our results demonstrated that among investigated cytokine genes IL-10 and TGF-β were significantly upregulated in patients with CRC compared to the control group, while the expression of IL-23 mRNA was significantly decreased in CRC patients. We observed significantly increased mRNA levels in CRC patients’ PBMC before surgery for IL-10 and TGF-β compared to both postoperative and control groups. We also found a significant upregulation of iNOS in early compared to advanced CRC.

Conclusions

Based on the results we can assume that PBMC gene expression programming in CRC patients drives local differentiation of Th cells towards Treg instead of the Th1 anti-tumour subpopulation.

HIV-Infected Spleens Present Altered Follicular Helper T Cell (Tfh) Subsets and Skewed B Cell Maturation

Follicular helper T (Tfh) cells within secondary lymphoid organs control multiple steps of B cell maturation and antibody (Ab) production. HIV-1 infection is associated with an altered B cell differentiation and Tfh isolated from lymph nodes of HIV-infected (HIV⁺) individuals provide inadequate B cell help in vitro. However, the mechanisms underlying this impairment of Tfh function are not fully defined. Using a unique collection of splenocytes, we compared the frequency, phenotype and transcriptome of Tfh subsets in spleens from HIV negative (HIV^-) and HIV⁺ subjects. We observed an increase of CXCR5⁺PD-1^highCD57^-Tfh and germinal center (GC) CD57+ Tfh in HIV⁺ spleens. Both subsets showed a reduced mRNA expression of the transcription factor STAT-3, co-stimulatory, regulatory and signal transduction molecules as compared to HIV^- spleens. Similarly, Foxp3 expressing follicular regulatory T (Tfr) cells were increased, suggesting sustained GC reactions in chronically HIV⁺ spleens. As a consequence, GC B cell populations were expanded, however, complete maturation into memory B cells was reduced in HIV⁺ spleens where we evidenced a compromised production of B cell-activating cytokines such as IL-4 and IL-10. Collectively our data indicate that, although Tfh proliferation and GC reactions seem to be ongoing in HIV-infected spleens, Tfh “differentiation” and expression of costimulatory molecules is skewed with a profound effect on B cell maturation.

Interaction analysis of IL-12A and IL-12B polymorphisms with the risk of colorectal cancer

IL-12 is an antitumor cytokine with functions of inhibiting tumor growth, invasion, and metastasis, indicating that IL-12 is a promising candidate for cancer treatment. The aim of this study was to investigate the association of IL-12A rs568408, IL-12A rs2243115, and IL-12B rs3212227 with the susceptibility to colorectal cancer (CRC). Two hundred and fifty-seven histopathologically confirmed CRC patients and 236 age- and gender-matched controls were enrolled. The three polymorphisms were genotyped using a polymerase chain reaction-restriction fragment length polymorphism assay. We found that the IL-12A rs568408 AG/AA genotypes were associated with an increased risk of CRC with an adjusted odds ratio (OR) of 1.66 (95 % confidence interval (CI), 1.11-2.48). Stratified analyses showed that patients carrying the IL-12B rs3212227AC/CC genotypes had a 1.97-fold increased risk of tumor metastasis (OR = 1.97; 95 % CI, 1.04-3.70). Gene-gene interaction analysis showed that subjects carrying the IL-12A rs568408AG/AA and IL-12B rs3212227AA genotypes had a 2.40-fold increased risk of CRC (OR = 2.40; 95 % CI, 1.14-5.07) and individuals carrying the IL-12A rs568408AG/AA and IL-12B rs3212227AC/CC genotypes had a 1.93-fold increased risk of CRC (OR = 1.93; 95 % CI, 1.10-3.41). These findings indicate that IL-12A rs568408 and IL-12B rs3212227 may be related to the development of CRC.

Tumour microenvironment of both early- and late-stage colorectal cancer is equally immunosuppressive

BACKGROUND

Tumour microenvironment (TME) of advanced colorectal cancer (CRC) suppresses dendritic cell (DC) maturation. Here, our aim was to determine how the microenvironment of early-stage tumours influences DCs.

METHODS

Tumour-conditioned media (TCM) was generated by culturing explant tumour tissue in vitro (n=50). Monocyte-derived DCs (MDDCs) of healthy donors or cancer patients were pretreated with TCM and stimulated with lipopolysaccharide (LPS). DC maturation was assessed by flow cytometry and cytokine production measured by ELISA.

RESULTS

TCM from both early- and late-staged tumours abrogated LPS-induction of IL-12p70 secretion, while increasing IL-10. The profile of inflammatory mediators in TCM was similar across stages, and all increased pSTAT3 expression by DCs.CRC patient DCs (n=31) secreted low levels of IL-12p70 and failed to upregulate expression of maturation markers in response to LPS. Furthermore, in vitro culture of autologous DCs with TCM did not change the hypo-responsiveness of patient DCs.

CONCLUSION

Our data demonstrates that the TME of all stages of CRC contains inflammatory mediators capable of suppressing local DCs. MDDCs obtained from CRC patients are hyporesponsive to stimuli such as LPS. Measures to reverse the negative influence of the TME on DCs will optimise cancer vaccines in both early- and late-stage CRC.

Association of interleukin-12 polymorphisms and serum IL-12p40 levels with osteosarcoma risk

No previous studies reported the association of IL-12 polymorphisms with osteosarcoma. We aimed to investigate the association in a Chinese population. IL-12A rs568408, rs2243115, and IL-12B rs3212227 polymorphisms were evaluated in a case-control study of 106 osteosarcoma patients and 210 health controls by using polymerase chain reaction-restriction fragment length polymorphism. Serum IL-12p40 levels were measured by enzyme-linked immunosorbent assay. The serum IL-12p40 levels were significantly higher in controls than those in osteosarcoma patients (p<0.01). Genotypes of rs568408 GA and GA/AA, and rs3212227 CC and AC/CC were associated with the risk of osteosarcoma (rs568408 GA: odds ratios [OR]=1.86, 95% confidence intervals [CI]=1.11-3.12; GA/AA: OR=1.75, 95% CI=1.06-2.89, and rs3212227 CC: OR=2.70, 95% CI=1.38-5.28; CC/AC: OR=1.73, 95% CI=1.03-2.90). Moreover, rs3212227 CC/AC genotypes were significantly associated with decreased serum IL-12p40 levels in osteosarcoma patients compared to AA genotypes (p=0.035). Stratification analysis showed no associations between rs3212227 variant and the patients' gender, tumor location, and metastasis. Our data suggest that the serum IL-12p40 levels associate with the risk of osteosarcoma and are regulated by IL-12B rs3212227 polymorphism. The IL-12A rs568408 and IL-12B rs3212227 may confer the susceptibility to osteosarcoma risk.