Role of interleukin-12 in determining differential kinetics of invariant natural killer T cells in response to differential burden of Listeria monocytogenes

Association of interleukin-12B gene polymorphisms and mRNA expression with preeclampsia

OBJECTIVE

To explore the effects of functional genetic polymorphisms of the interleukin-12B (IL-12B) gene on the susceptibility to preeclampsia in northern Chinese women.

STUDY DESIGN

Maternal peripheral blood from 306 preeclamptic women and 310 control women and the placentas from 52 preeclamptic and 55 control women were collected. Two polymorphisms (rs17860508 and rs3212227) of the IL-12B gene were genotyped by polymerase chain reaction (PCR) with a direct sequencing method. The mRNA expression of IL-12B in the placentas was measured by quantitative real-time PCR (qRT-PCR).

RESULTS

Significant differences were observed between preeclamptic women and the control group in the genotype frequencies of rs17860508 (P = 0.017). Compared with the TTAGAG/TTAGAG genotype of rs17860508, the GC/GC genotype were associated with a higher risk of preeclampsia (adjusted OR: 1.95; 95% CI = 1.18-3.22; P = 0.009), especially the early-onset preeclampsia (adjusted OR: 2.40; 95% CI = 1.23-4.68; P = 0.010). The qRT-PCR results showed that the mRNA levels of IL-12B were significantly higher in the placentas of preeclampsia patients than that in the placentas of controls (P = 0.001). Moreover, the expression of IL-12B mRNA was significantly higher in the placentas of patients carrying the GC/GC genotype than in those carrying the TTAGAG/GC (P = 0.007) and TTAGAG/TTAGAG (P = 0.005) genotypes.

CONCLUSION

The GC/GC genotype of rs17860508 polymorphism may be a risk factor for the early-onset preeclampsia by upregulating the expression of IL-12B in northern Chinese women.

A Functional Polymorphism in the Promoter Region of Interleukin-12B Increases the Risk of Colorectal Cancer

Objective

To investigate whether the polymorphisms of interleukin-12B (IL-12B) were associated with the risk of developing colorectal cancer (CRC). Patients and Methods. Genotypes of rs17860508 and rs3212227 were determined by polymerase chain reaction with a direct sequencing method in 329 CRC patients and 342 matched healthy control subjects. The expression of IL-12B) were associated with the risk of developing colorectal cancer (CRC).

Results

Compared with TTAGAG/TTAGAG genotype of rs17860508, the GC/GC and TTAGAG/GC genotypes may significantly increase the risk of CRC (OR = 1.81, 95% CI = 1.18-2.78; OR = 1.46, 95% CI = 1.01-2.12, respectively). Furthermore, the mRNA levels of IL-12B) were associated with the risk of developing colorectal cancer (CRC). P=0.009) and TTAGAG/TTAGAG (P=0.009) and TTAGAG/TTAGAG (.

Conclusion

These data suggested that the rs17860508 GC/GC genotype might upregulate IL-12B expression at the transcriptional level and thus increase the risk of CRC.IL-12B) were associated with the risk of developing colorectal cancer (CRC).

Association of Interleukin-12A rs568408 with Susceptibility to Asthma in Taiwan

Asthma is an inflammatory disease and interleukin 12 (IL-12) may play a regulatory role in allergen-induced inflammation. The aim of this study was to investigate the association of polymorphisms in IL-12A/IL-12B with asthma. The asthma group included 198 adult patients and the control group included 453 individuals without asthma that were frequency-matched by gender and age. The distribution of genotypic and allelic frequencies of IL-12A rs568408 demonstrated significant differences between case and control groups. Specifically, the percentages of AA genotype of IL-12A rs568408 was significantly higher among asthmatic patients in Taiwan than healthy controls, compared to GG genotype. No significant difference was observed among the IL-12A rs2243115 and IL-12B rs3212227 genotypes between case and control groups. In addition, the A allele at IL-12A rs568408 was associated with more severe symptoms (P = 0.0085) among asthmatic patients. These results suggest that IL-12A rs568408 may contribute to the etiology and symptoms severity of asthma, indicating its usefulness as a predictive and diagnostic biomarker of asthma.

Interleukin-12B+1188A/C polymorphism contributes to increased hepatocellular carcinoma susceptibility: evidence from a meta-analysis

BACKGROUND

Interleukin-12 (IL-12) is a multifunctional cytokine that induces interferon (IFN)-γ secretion and plays an important role in antitumor immunity. The IL-12B +1188A/C polymorphism was found to correlate with a decreased cytokine production and/or activity, which may lead to increased susceptibility to cancers including hepatocellular carcinoma (HCC). Previous epidemiological studies investigating the association between IL-12B +1188A/C polymorphism and HCC risk reported inconsistent results. We performed a meta-analysis to derive a precise estimation of the association.

METHODS

All studies published up to July 2014 on the association between IL-12B +1188A/C polymorphism and HCC risk were identified by searching electronic databases including PubMed, Embase, Cochrane library, and Chinese Biomedical Literature database (CBM). Data were extracted by two independent authors and the odds ratios (ORs) together with corresponding 95% confidence intervals (CIs) were used to assess the association between IL-12B +1188A/C polymorphism and HCC risk.

RESULTS

Five studies with 1864 cases and 2077 controls were included in the meta-analysis. We observed that the IL-12B +1188A/C polymorphism was significantly correlated with increased HCC risk when all studies were pooled into the meta-analysis (CC vs. AA: OR=1.306, 95% CI 1.063-1.606, P=0.011; AC vs. AA: OR=1.193, 95% CI 1.014-1.405, P=0.034; CC+AC vs. AA: OR=1.260, 95% CI 1.098-1.445, P=0.001). In subgroup analyses by ethnicity, source of control, and study quality, significant increased HCC risk was found in Asians, hospital-based studies, and high quality studies.

CONCLUSIONS

The present meta-analysis suggests that the IL-12B+1188A/C polymorphism is a low-penetrant risk factor for HCC development, especially among Asians. Further large and well-designed studies are needed to confirm this association.

Potential celiac children: 9-year follow-up on a gluten-containing diet

OBJECTIVES

Potential celiac disease (CD) is defined by the presence of serum anti-tissue-transglutaminase (anti-TG2) antibodies and normal duodenal mucosa. The major clinical problem is the management of asymptomatic patients and how to predict the development of villous atrophy. This prospective longitudinal cohort study describes the natural history of potential CD up to 9 years and explores risk factors associated with the development of mucosal damage.

METHODS

Two hundred and ten potential CD children were eligible for the study; 175/210 asymptomatic children were left on a gluten-containing diet. Antibodies and clinical symptoms were checked every 6 months, and a small bowel biopsy was taken every 2 years to evaluate histological, immunohistochemical, and anti-TG2 deposits. Patients were genotyped for HLA and a set of non-HLA CD-associated genes.

RESULTS

Forty-three percent of patients showed persistently elevated anti-TG2 level, 20% became negative during follow-up, and 37% showed a fluctuant anti-TG2 course with transiently negative values. At 3 years of follow-up, 86% of cases remained potential; 73 and 67% still had normal duodenal architecture at 6 and 9 years, respectively. Male sex, slight mucosal inflammation at time 0, and a peculiar genetic profile delineate a cohort of individuals who were prone to develop mucosal damage during time.

CONCLUSIONS

A sizeable proportion of asymptomatic potential celiac patients showed fluctuation or negativization of antibody production, and many of these, with persistently positive anti-TG2, did not develop mucosal damage after 9 years of follow-up. Celiac population is a multivariate aggregate of individuals with different genetic and phenotypic profiles. Caution is required before prescribing a gluten-free diet for life to asymptomatic individuals with potential CD.

CD1d and natural killer T cells in immunity to Mycobacterium tuberculosis

The critical role of peptide antigen-specific T cells in controlling mycobacterial infections is well documented in natural resistance and vaccine-induced immunity against Mycobacterium tuberculosis. However, many other populations of leukocytes contribute to innate and adaptive immunity against mycobacteria. Among these, non-conventional T cells recognizing lipid antigens presented by the CD1 antigen presentation system have attracted particular interest. In this chapter, we review the basic immunobiology and potential antimycobacterial properties of a subset of CD1-restricted T cells that have come to be known as Natural Killer T cells. This group of lipid reactive T cells is notable for its high level of conservation between humans and mice, thus enabling a wide range of highly informative studies in mouse models. As reviewed below, NKT cells appear to have subtle but potentially significant activities in the host response to mycobacteria. Importantly, they also provide a framework for investigations into other types of lipid antigen-specific T cells that may be more abundant in larger mammals such as humans.

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.

Dissociated expression of natural killer 1.1 and T-cell receptor by invariant natural killer T cells after interleukin-12 receptor and T-cell receptor signalling

Invariant (i) natural killer T (NKT) cells become undetectable after stimulation with alpha-galactosylceramide (alpha-GalCer) or interleukin (IL)-12. Although down-modulation of surface T-cell receptor (TCR)/NKR-P1C (NK1.1) expression has been shown convincingly after stimulation with alpha-GalCer, it is unclear whether this also holds true for IL-12 stimulation. To determine whether failure to detect iNKT cells after IL-12 stimulation is caused by dissociation/internalization of TCR and/or NKR-P1C, or by block of de novo synthesis of these molecules, and to examine the role of IL-12 in the disappearance of iNKT cells after stimulation with alpha-GalCer, surface (s)/cytoplasmic (c) protein expression, as well as messenger RNA (mRNA) expression of TCR/NKR-P1C by iNKT cells after stimulation with alpha-GalCer or IL-12, and the influence of IL-12 neutralization on the down-modulation of sTCR/sNKR-P1C expression by iNKT cells after stimulation with alpha-GalCer were examined. The s/cTCR(+ )s/cNKR-P1C(+) iNKT cells became undetectable after in vivo administration of alpha-GalCer, which was partially prevented by IL-12 neutralization. Whereas s/cNKR-P1C(+) iNKT cells became undetectable after in vivo administration of IL-12, s/cTCR(+) iNKT cells were only marginally affected. mRNA expression of TCR/NKR-P1C remained unaffected by alpha-GalCer or IL-12 treatment, despite the down-modulation of cTCR and/or cNKR-P1C protein expression. By contrast, cTCR(+ )cNKR-P1C(+) sTCR(-) sNKR-P1C(-) iNKT cells and cNKR-P1C(+) sNKR-P1C(-) iNKT cells were detectable after in vitro stimulation with alpha-GalCer and IL-12, respectively. Our results indicate that TCR and NKR-P1C expression by iNKT cells is differentially regulated by signalling through TCR and IL-12R. They also suggest that IL-12 participates, in part, in the disappearance of iNKT cells after stimulation with alpha-GalCer by down-modulating not only sNKR-P1C, but also sTCR.

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.

Intracellular bacterial infection and invariant NKT cells

The invariant (i) natural killer (NK)T cells represent a unique subset of T lymphocytes which express the V alpha 14 chain of the T cell receptor (TCR), that recognizes glycolipid antigens presented by the nonpolymorphic major histocompatibility complex (MHC) class I-like antigen presentation molecule CD1d, and they participate in protection against some microbial pathogens. Although iNKT cells have originally been regarded as T cells co-expressing NKR-P1B/C (NK1.1: CD 161), they do not seem to consistently express this marker, since NK1.1 surface expression on iNKT cells undergoes dramatic changes following facultative intracellular bacterial infection, which is correlated with functional changes of this cell population. Accumulating evidence suggests that NK1.1 allows recognition of "missing-self", thus controlling activation/inhibition of NK1.1-expressing cells. Therefore, it is tempting to suggest that iNKT cells participate in the regulation of host immune responses during facultative intracellular bacterial infection by controlling NK1.1 surface expression. These findings shed light not only on the unique role of iNKT cells in microbial infection, but also provide evidence for new aspects of the NK1.1 as a regulatory molecule on these cells.

Liver invariant NKT cells and listeriosis

The invariant (i) NKT cells represent unique T lymphocytes expressing TCRValpha14. Although iNKT cells have been regarded as T lymphocytes expressing NK1.1, they do not consistently express this marker. NK1.1 allows recognition of "missing-self" and thus controls inhibition/activation of iNKT cells. It is thus tempting to assume that iNKT cells participate in the regulation of host immune responses during microbial infection by controlling NK1.1 expression. These findings shed light on the unique role of iNKT cells in microbial infection and provide an evidence for unique aspects of the NK1.1 on these cells as a regulatory molecule.