IL21 and IL21R polymorphisms and their interactive effects on serum IL-21 and IgE levels in patients with chronic hepatitis B virus infection

IL21 inhibits miR-361-5p to promote MAP3K9 and further aggravate the progression of shoulder arthritis

OBJECTIVE

This research aimed to explore IL-21/miR-361-5p/MAP3K9 expression in shoulder arthritis and identify its regulatory pathways.

METHODS

We established a rat shoulder arthritis model, then quantified IL21 and miR-361-5p in synovial fluid using ELISA and monitored the arthritis development. Additionally, IL21's effect on miR-361-5p levels in cultured human chondrocytes (HC-a) was assessed. Chondrocyte cell cycle status and apoptosis were measured via flow cytometry. Interactions between miR-361-5p and MAP3K9 were confirmed through dual-luciferase reporting and bioinformatic scrutiny. Protein levels of MAP3K9, p-ERK1/2, p-NF-κB, MMP1, and MMP9 were analyzed by Western blots.

RESULTS

IL21 levels were elevated, while miR-361-5p was reduced in the synovial fluid from arthritic rats compared to healthy rats. IL21 was shown to suppress miR-361-5p in chondrocytes leading to hindered cell proliferation and increased apoptosis. Western blots indicated that miR-361-5p curbed MAP3K9 expression, reducing MMP activity by attenuating the ERK1/2/NF-κB pathway in chondrocytes.

CONCLUSION

IL21 upregulation and miR-361-5p downregulation characterize shoulder arthritis, resulting in MAP3K9 overexpression. This chain of molecular events boosts MMP expression in chondrocytes and exacerbates the condition's progression.

Interleukin-21 receptor gene polymorphism (rs2285452 A/G) is associated with susceptibility to Behçet's disease

Behçet's disease (BD) is a chronic auto inflammatory disorder of unknown aetiology. Recently, the dysregulation of interleukin-21 receptor (IL-21R) has been incriminated in different autoimmune and auto-inflammatory diseases, such as systemic lupus erythematous, rheumatoid arthritis, and type 1 diabetes. Herein, we aimed to investigate the association of two Il-21R gene polymorphisms with BD. IL-21R rs2214537 and IL-21R rs2285452 genotypings were investigated in a cohort of 110 adult patients with BD and 116 age and gender unmatched healthy controls. Genotyping was performed by mutagenically separated polymerase chain reaction with newly designed primers. IL-21R rs2285452 genotypes and alleles distribution were statistically different between patients with BD and controls. GA and AA genotypes carrying the minor A allele were more frequent in patients with BD than in healthy controls (37.3% and 11.8% vs. 23.3% and 3.4%, respectively). The minor A allele was associated with an increased BD risk (odds ratios = 2.42, 95% confidence interval = 1.214.87, p = .005). IL-21R rs2214537 GG genotype was found to be associated with susceptibility to BD in the recessive model (GG vs. CC + CG; p = .046, OR =  1.91, 95% CI =  1.003.650. IL-21R rs2285452 and IL-21R rs2214537 were not in linkage disequilibrium (D' = 0.42). The AG haplotype was more frequently observed in patients with BD than in controls (0.247 vs. 0.056, p =  .0001). This study for the first time reports the association of IL-21R rs2285452 and IL-21R rs2214537 with BD. Functional studies are required to elucidate the exact role of these genetic variants.

A Meta-Analysis of the Association Between Genetic Polymorphisms in IL-12, IL-17, and IL-21 and Risk of Hepatitis B Virus Infection

Cytokine imbalance is an important feature in the occurrence and outcome of hepatitis B virus (HBV). Single nucleotide polymorphisms (SNPs) within cytokine genes may affect the protein expression and eventually contribute to the susceptibility of HBV infection. The association between interleukin (IL)-12, IL-17, or IL-21 and the risk of HBV infection has been extensively studied, but yielding equivocal results. The aim of this meta-analysis was to determine the impact of SNPs in IL-12, IL-17, and IL-21 on the risk of HBV infection. We retrieved studies evaluating whether SNPs in IL-12, IL-17, and IL-21 influenced HBV infection from electronic databases, including PUBMED, Web of Science, EBOCO, OVID, and Embase. Summarized odds ratios (ORs) and confidence intervals (CIs) were calculated using STATA software. Under a homozygous comparison, the IL-12A rs568408 was associated with an increased risk of HBV infection in both overall analysis (OR = 1.68, 95% CI, 1.12-2.53) and Caucasians (OR = 1.80, 95% CI, 1.14-2.84). Under a dominant genetic model, the similarly higher risk was also observed in overall analysis (OR = 3.62, 95% CI, 3.08-4.24), Caucasians (OR = 3.29, 95% CI, 2.67-4.05), high-quality studies (OR = 3.29, 95% CI, 2.61-4.14), and low-quality studies (OR = 3.95, 95% CI, 3.17-4.93). Although no significant association was observed between IL-17A rs2275913 and the risk of HBV infection in overall comparison, subgroup analysis revealed that the IL-17A rs2275913 AA genotype was associated with a reduced risk in Asians (OR = 0.72, 95% CI, 0.57-0.91) and high-quality studies (OR = 0.71, 95% CI, 0.55-0.92). However, no significant association of IL12B rs3212227, IL-17A rs2275913, IL-21 rs2221903, and rs907715 with HBV infection was observed. In conclusion, we provide evidence that IL-12A rs568408 was associated with an increased risk of HBV infection and IL-17A rs2275913 AA genotype was a protective factor against HBV infection in Asians.

Multi-faceted regulation of IgE production and humoral memory formation

IgE antibodies play a protective role against parasites and environmental toxins by its strong effector functions. However, aberrant IgE production can contribute to the development of allergic disorders, and thus is tightly regulated. Beside its very short half-life, IgE is normally produced only transiently and its affinity maturation is limited under physiological immune responses. Although such distinct characteristics of IgE among Ig classes are well-known, the underlying molecular mechanisms have not been understood until recently. Somatic or genetic defects of such mechanisms can lead to pathogenesis of allergic diseases. In this review, we summarize recent advances in our understanding of the mechanisms that control the production of IgE and formation of IgE-type humoral memory, focusing on the B cell immune responses.

IL-21 is a broad negative regulator of IgE class switch recombination in mouse and human B cells

IgE antibodies may elicit potent allergic reactions, and their production is tightly controlled. The tendency to generate IgE has been thought to reflect the balance between type 1 and type 2 cytokines, with the latter promoting IgE. Here, we reevaluated this paradigm by a direct cellular analysis, demonstrating that IgE production was not limited to type 2 immune responses yet was generally constrained in vivo. IL-21 was a critical negative regulator of IgE responses, whereas IFN-γ, IL-6, and IL-10 were dispensable. Follicular helper T cells were the primary source of IL-21 that inhibited IgE responses by directly engaging the IL-21 receptor on B cells and triggering STAT3-dependent signaling. We reconciled previous discordant results between mouse and human B cells and revealed that the inhibition of IgE class switch recombination by IL-21 was attenuated by CD40 signaling, whereas IgG1 class switch recombination was potentiated by IL-21 in the context of limited IL-4. These findings establish key features of the extrinsic regulation of IgE production by cytokines.

Human genetic susceptibility to hepatitis B virus infection

Hepatitis B virus (HBV) infection is still a serious health threat worldwide. The outcomes of HBV infection consist of spontaneous HBV clearance and chronic HBV infection. Multiple factors contribute to the disparity of HBV infection outcomes, including host factors, viral factors and environmental factors. The present review comprehends the current researches mainly focusing on the relationships between genetic determinants, including single nucleotide polymorphisms (SNPs) and haplotypes, and susceptibility of HBV infection, namely chronic (persistent) HBV infection and HBV clearance. A number of determinants in the chromosomes, including mutations in human leukocyte antigens (HLAs), cytokines genes, toll-like receptors (TLRs), and other genes are related to the human susceptibility to HBV infection. Among the above variants, some of those in HLAs have been studied and replicated in multiple-ethnic populations and came to consistent conclusions, while some others are novel and need to be evaluated further.

IL-17 and IL-21 polymorphisms in relation to HBV related hepatocellular carcinoma in Chinese Han population

OBJECTIVE

Inflammatory cytokine gene polymorphisms may influence the hepatic and extrahepatic HBV-related disease. In this study, we aimed to investigate the relationship between polymorphisms of IL-17, IL-21 gene and HBV related hepatocellular carcinoma in Chinese Han population.

METHODS

We performed a multi-center study comprised 866 HBV-related hepatocellular carcinoma (HCC) patients and 1086 unrelated patients with a diagnosis of chronic hepatitis B (CHB) as control to evaluate the effects of IL-17 (rs4711998), IL-21 SNPs (rs12508721, rs13143866 and rs2221903) and the susceptibility of HCC. MassARRAY technology was utilized to genotype. Enzyme-linked immunosorbent assay (ELISA) was used to detect the serum IL-17 and IL-21 level. Quantitative real time polymerase chain reaction (qRT-PCR) was used to analyze the serum viral loads.

RESULTS

In logistic regression analysis, our results showed the frequency of rs4711998 allele G in CHB group was significantly higher than that in HCC group (P = 0.042, 0.859(0.743-0.994)), and it is present only among females. Compared to HCC group, rs13143866 A allele was more likely to appear in HCC group (P = 0.015, 1.268 (1.049-1.532)). The frequency of AA also showed different between HCC group and CHB groups (P = 0.011, 3.135 (1.292-7.603)), which showed strong sex-specific relationships. ELISA showed a higher serum IL-17 and IL-21 expression in HCC patients compared to CHB patients (P all <0.05). Haplotype rs12508721C/rs13143866A/rs2221903T in male HCC group was statistically higher than in male CHB group(P = 0.013) but not in females (P > 0.05).

CONCLUSION

We suggested rs4711998 allele A as risk factors for women to develop HBV related-HCC in Chinese Han population. rs13143866 allele A as risk factors to develop HBV related-HCC in Chinese male population. Male patients with haplotype rs12508721C/rs13143866A/rs2221903T may with 1.3-fold risk for HBV-related HCC.

Characterization and bioactivity of grass carp (Ctenopharyngodon idella) interleukin-21: Inducible production and involvement in inflammatory regulation

In mammals, interleukin 21 (IL-21) is a broad pleiotropic cytokine that plays critical roles in the development of several inflammatory and autoimmune diseases. In fish, functional information of Il-21 is limited, and its role in immune response is largely unknown. In the present study, we cloned a coding sequence of grass carp (Ctenopharyngodon idella) il21 gene (gcil21). To characterize the release patterns and biological activity of gcIl-21, we prepared recombinant gcIl-21 (rgcIl-21) and obtained the polyclonal antibody with gcIl-21 specificity. Western blotting analysis showed that in grass carp head kidney leukocytes (HKLs), gcIl-21 was undetected in culture supernatant of untreated cells but drastically induced by heat-killed Aeromonas hydrophila (A. hydrophila), uncovering the release features of gcIl-21 and its possible involvement in immune response. Subsequent functional experiments revealed that rgcIl-21 did not affect the mRNA expression of grass carp il1b and tgfb, but induced a strong expression of grass carp il10, and to a lesser extent of grass carp tnfa in HKLs, suggesting a dominant effect of gcIl-21 in modulating Il-10 signaling as seen in rainbow trout and mammals. Furthermore, in vivo studies showed that intraperitoneal injection of rgcIl-21 was able to increase the survival rate of grass carp infected with live A. hydrophila, and reduce the pathological responses caused by the same pathogenic bacteria in head kidney and intestine. Taken together, these results for the first time revealed the close relationship of fish Il-21 production and function with inflammatory responses, and highlighted its anti-bacterial and anti-inflammatory ability, thereby providing a new insight into host defense mechanisms in fish.

Host Genetic Determinants of Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection is still a major health problem worldwide. Recently, a great number of genetic studies based on single nucleotide polymorphisms (SNPs) and genome-wide association studies have been performed to search for host determinants of the development of chronic HBV infection, clinical outcomes, therapeutic efficacy, and responses to hepatitis B vaccines, with a focus on human leukocyte antigens (HLA), cytokine genes, and toll-like receptors. In addition to SNPs, gene insertions/deletions and copy number variants are associated with infection. However, conflicting results have been obtained. In the present review, we summarize the current state of research on host genetic factors and chronic HBV infection, its clinical type, therapies, and hepatitis B vaccine responses and classify published results according to their reliability. The potential roles of host genetic determinants of chronic HBV infection identified in these studies and their clinical significance are discussed. In particular, HLAs were relevant for HBV infection and pathogenesis. Finally, we highlight the need for additional studies with large sample sizes, well-matched study designs, appropriate statistical methods, and validation in multiple populations to improve the treatment of HBV infection.

The association between interleukin-21 (rs2055979G/T) gene polymorphism and the risk of hepatocellular carcinoma and metastasis in patients with hepatitis C virus

Cancer prevalence is critically increasing worldwide; accordingly, improved prediction and therapeutic tools are necessary. Interleukin (IL)-21 is a potent antitumor cytokine, and the relationship between its gene variations and cancer risk is well established. Nevertheless, so far no study has investigated its role in hepatocellular carcinoma (HCC) progression and metastasis in hepatitis C virus (HCV)-infected people. Therefore, the present investigation was led on 267 Egyptian participants, involving 177 patients with HCV of which 90 patients had HCC (HCC group), 87 patients without HCC (non-HCC group), and 90 unrelated healthy controls. The association between rs2221903A/G and rs2055979G/T of the IL-21 gene and the risk of HCC and metastasis, as well as the clinico-pathological features, were analyzed. While rs2221903A/G polymorphism was not polymorphic in our cohort, patients carrying the genotype TT and allele T of the rs2055979G/T polymorphism had a significantly lower risk of HCC when comparing with HCC group and healthy controls. Also, participants carrying the aforementioned genotype and allele had a significantly lower risk of metastasis when comparing metastatic group with both nonmetastatic group and control group. The rs2055979G/T polymorphism was not significantly associated with clinico-pathological features of HCC. This is the first study to report a relationship between an intronic polymorphism in IL-21 gene and HCC and metastasis risk in the Egyptian people, in addition to identifying a potential new marker for the early detection and treatment of HCC.

Interleukin-21 receptor gene polymorphism is associated with hepatitis B virus-related hepatocellular carcinoma in Chinese patients

Background

We investigated the relationship between hepatitis B virus (HBV)‐related pathogenesis and single nucleotide polymorphisms (SNPs) in interleukin‐21 (IL‐21)‐JAK‐STAT signaling pathway genes.

Methods

We used the high‐resolution melting (HRM) method to genotype five SNPs (IL‐21 rs2221903, IL‐21 rs4833837, IL‐21 receptor (IL‐21R) rs2285452, JAK3 rs3008, and STAT3 rs1053023) in 546 HBV‐infected patients and 353 healthy Chinese subjects. The HBV‐infected patients were further divided into subgroups based on the HBV‐related pathologies: chronic hepatitis B (CHB), HBV‐related liver cirrhosis (LC), and HBV‐related hepatocellular carcinoma (HCC).

Results

There were no significant differences in the genotype and allele distributions of the five SNPs between the HBV‐infected patients and healthy subjects. The genotype and allele frequencies were similar in the two groups for IL‐21 rs2221903 (A>G, P = 0.83 and 0.67), rs4833837 (A>G, P = 0.80 and 0.49), IL‐21R rs2285452 (G>A, P = 0.25 and 0.68), STAT3 rs1053023 (A>G, P = 1.00 and 0.96), and JAK3 rs3008 (C>T, P = 0.32 and 0.54). However, patients with the IL‐21R rs2285452 AA genotype were more susceptible to HBV‐related HCC than those with the IL‐21R rs2285452 GA/GG genotype (P = 0.03, OR = 3.27, 95% CI = 1.16‐9.20). The serological marker model of “HBsAg+, HBeAg+, HBcAb+” was predominant among patients with HBV infection. However, there was no association between the genotype's distribution of the five SNPs and the serological marker models (P > 0.05).

Conclusions

These findings demonstrate that the IL‐21R rs2285452 AA genotype increases the risk of HBV‐related HCC in Chinese patients.

Association between Interleukin-21 and Interleukin-21 receptor gene polymorphisms with susceptibility to chronic hepatitis B virus infection and HBV spontaneous clearance in Iranian population

Hepatitis B virus (HBV) infection is a major public health concern due to the infection often leads to chronic infection, liver cirrhosis and also liver cancer. The host immune response to HBV infection and also genetic background play significant role in outcome of infection. Single nucleotide polymorphisms (SNPs) are the most important kind of variation in genetic sequences that caused by point mutations. As cytokines have major roles in viral infections, it seems that cytokine gene polymorphisms are independently associated with response to viral infections. Interleukin 21 (IL-21) plays an influential role in both innate and adaptive immune responses. Its specific receptor, IL-21R, produced and located on the surface of T, B and natural killer (NK) cells and is critical for the proliferation and differentiation of these immune effector cells. Many studies confirmed that the IL-21 involved in response to viral infections. We aimed to investigate the association of G/T IL-21 (rs2055979) and C/T IL-21R (rs3093390) gene polymorphisms with chronic hepatitis B virus infection and HBV spontaneous clearance in Iranian population.

METHODS

In this study, blood samples were gathered from 320 patients with chronic HBV and 310 healthy controls and also 120 HBV spontaneous clearance individuals. Following genomic DNA extraction, genotypes of the selected SNPs determined by PCR and restriction fragment length polymorphism (RFLP) method. The results were analyzed by SPSS software using Chi-square, Logistic Regression, ANOVA and Independent Samples t-Test.

RESULTS

According to our results, in IL-21R (rs3093390 C/T) gene polymorphism, allele frequency of T is statistically different in the HBV spontaneous clearance group compared to chronic HBV cases. But there is no significant difference between G/T IL-21 (rs2055979) and C/T IL-21R (rs3093390) genotypes distribution in three groups. Also we found that higher serum aspartate transaminase (AST) level in HBV spontaneous clearance group is significantly associated with TT genotype of IL-21 (rs2055979) compared to GG genotype (P value = 0.006).

DISCUSSION

Our results showed that T allele frequency in IL-21R (rs3093390 C/T) gene polymorphism could consider as a host genetic factor for HBV spontaneous clearance. Probably we can serve it as a potential prognostic genetic marker for spontaneous clearance of HBV infection.

Role of interleukin-21 and interleukin-21 receptor polymorphisms in the treatment of HBeAg-positive chronic hepatitis B patients with peginterferon

The aim of this study was to evaluate the relationship between interleukin-21 (IL-21) and interleukin-21 receptor (IL-21R) polymorphisms and the response to peginterferon alfa (PEG-IFN α) therapy in HBeAg-positive chronic hepatitis B (CHB) patients.A total of 143 HBeAg-positive CHB patients treated for 48 weeks with PEG-IFN α and followed up for 24 weeks post-treatment were retrospectively evaluated. Genotypes analysis was performed for IL-21 polymorphisms rs907715, rs2221903, and IL-21R polymorphisms rs3093301 and rs2285452. Serum IL-21 levels were measured by enzyme-linked immunosorbent assay.The end of virological response (EVR) rate was 46.9% (67/143) at the end of treatment, the sustained virological response (SVR) rate was 43.4% (62/143) and the complete response (CR) rate was 32.1% (46/143) at 24 weeks post-treatment. Patients who carried IL-21 rs 2221903 genotype AA had a rather higher rate of EVR (response rate: 52.4%, odds ratio [OR] 0.42, 95% confidence interval [CI]: 0.19-0.91, P = .021), SVR (response rate: 47.6%, OR 0.43, 95% CI: 0.19-0.95, P = .028), and CR (response rate: 38.1%, OR 0.31, 95% CI: 0.12-0.79, P = .014) when compared to those had AG genotype. Meanwhile, IL-21rs 2221903 genotype AA was also independently associated with markedly reduced HBsAg levels (>1og10 IU/mL) after 24 weeks treatment and low HBsAg levels (<100 IU/mL) at the end of treatment. IL-21 rs907715 AG/GG genotype was independently associated with SVR (OR: 2.92, 95% CI: 0.98-8.6, P = .039; OR: 3.23, 95% CI: 1.0-10.4, P = .039). Patients with IL-21 rs907715 AG/GG genotype had higher serum IL-21 levels than those with rs907715 AA genotype (P = .021).IL-21 rs2221903 and rs907715 polymorphisms were significantly associated with the treatment response to PEG-IFN α among Chinese HBeAg-positive CHB patients.

Interleukin-21 gene polymorphism rs2221903 is associated with disease activity in patients with rheumatoid arthritis

INTRODUCTION

Interleukin-21 (IL-21) is a cytokine which plays a significant role in the pathogenesis and disease activity of rheumatoid arthritis (RA). Genetic polymorphisms in the IL-21 gene may alter the synthesis of IL-21. The aim of this study was to examine IL-21 and IL-21R polymorphisms in patients with RA.

MATERIAL AND METHODS

We examined 422 patients with RA and 338 healthy controls. Single nucleotide polymorphisms (SNPs) within the IL-21 (rs6822844 G>T, rs6840978 C>T, rs2221903 T>C) and IL-21R (rs2285452 G>A) genes were genotyped using TaqMan genotyping assays.

RESULTS

There were no statistically significant differences in the distribution of studied genotypes and alleles between RA patients and the control group. To examine whether IL-21 polymorphisms affect disease activity in RA patients, we compared the distribution of IL-21 genotypes between patients with DAS28 ≤ 2.5 (patients with remission of disease symptoms) and patients with DAS28 > 2.5 (patients with active RA). Among patients with DAS28 > 2.5, increased prevalence of rs2221903 CT and CC genotypes was observed (OR = 1.54; 95% CI: 1.04-2.28; p = 0.035).

CONCLUSIONS

The results of this study suggest that IL-21 and IL-21R gene polymorphisms are not risk loci for RA susceptibility, whereas the IL-21 rs2221903 polymorphism is associated with disease activity.

Association between interleukin-21 gene polymorphisms (rs12508721) and HBV-related hepatocellular carcinoma

Interleukin-21 (IL-21), as a multifunctional cytokine, plays an important role in many diseases, such as cancer, inflammatory and autoimmune diseases. We aimed to investigate the relationship between polymorphisms of IL-21 gene and susceptibility of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) in a Chinese population. Studied subjects were divided into three groups: 100 patients with HBV-related HCC, 115 patients with chronic HBV infection and 127 healthy controls. Genomic DNA was isolated from peripheral blood, and the polymerase chain reaction-ligase detection reaction (PCR-LDR) method was used to genotype the SNPs (rs2221903, rs907715 and rs12508721) within IL-21 gene. Our results showed that IL-21 polymorphisms were associated with the risk of HCC and chronic HBV infection when compared with healthy controls. The rs2221903A/G AG genotype was associated with a higher risk of chronic HBV infection when compared with healthy controls [AG versus AA + GG, P = 0.036, OR = 1.898, 95%CI = 1.038-3.471]. The rs12508721C/T TT genotype was related with a lower risk of chronic HBV infection and HBV-related HCC than in healthy controls [TT versus CT + CC, P = 0.026, OR = 0.451, 95%CI = 0.221-0.920; P = 0.049, OR = 0.482, 95%CI = 0.231-1.005]. No significant difference in the genotype and allele distrubutions of rs907715G/A SNP was observed in the HBV-related HCC group, chronic HBV-infected group and the healthy control group when compared to each other. Our findings suggest that the rs12508721T/C and rs2221903A/G polymorphisms of IL-21 gene are associated with the susceptibility of HBV-related HCC and chronic HBV infection. The genetic variant may in fact cause protection against the HBV-related HCC. However, the function in these SNPs of IL-21 gene needs to clarify the mechanisms involved in the pathogenesis of HBV-related HCC further.

CD4+CXCR5+ T cells activate CD27+IgG+ B cells via IL-21 in patients with hepatitis C virus infection

BACKGROUND

Chronic hepatitis C virus (HCV) infection causes the skewing and activation of B cell subsets, but the characteristics of IgG+ B cells in patients with chronic hepatitis C (CHC) infection have not been thoroughly elucidated. CD4+CXCR5+ follicular helper T (Tfh) cells, via interleukin (IL)-21 secretion, activate B cells. However, the role of CD4+CXCR5+ T cells in the activation of IgG+ B cells in CHC patients is not clear.

METHODS

The frequency of IgG+ B cells, including CD27-IgG+ B and CD27+IgG+ B cells, the expression of the activation markers (CD86 and CD95) in IgG+ B cells, and the percentage of circulating CD4+CXCR5+ T cells were detected by flow cytometry in CHC patients (n=70) and healthy controls (n=25). The concentrations of serum IL-21 were analyzed using ELISA. The role of CD4+CXCR5+ T cells in the activation of IgG+ B cells was investigated using a co-culture system.

RESULTS

A significantly lower proportion of CD27+IgG+ B cells with increased expression of CD86 and CD95 was observed in CHC patients. The expression of CD95 was negatively correlated with the percentage of CD27+IgG+ B cells, and it contributed to CD27+IgG+ B cell apoptosis. Circulating CD4+CXCR5+ T cells and serum IL-21 were significantly increased in CHC patients. Moreover, circulating CD4+CXCR5+ T cells from CHC patients induced higher expressions of CD86 and CD95 in CD27+IgG+ B cells in a co-culture system; the blockade of the IL-21 decreased the expression levels of CD86 and CD95 in CD27+IgG+ B cells.

CONCLUSIONS

HCV infection increased the frequency of CD4+CXCR5+ T cells and decreased the frequency of CD27+IgG+ B cells. CD4+CXCR5+ T cells activated CD27+IgG+ B cells via the secretion of IL-21.

IL17A gene polymorphism, serum IL17 and total IgE in Egyptian population with chronic HCV and hepatocellular carcinoma

BACKGROUND

Chronic infections with HCV (CHC) induce a chronic inflammation which can lead to liver fibrosis and subsequently cirrhosis. A recent study suggests a role of IL-17 polymorphism and serum IL17 in hepatitis B related HCC. These data indicate that the IL-17 G-197A polymorphism may be a good indicator for susceptibility to cancer development.

AIM

To investigate the role of the IL17A gene polymorphism, serum IL17 and total IgE in Egyptian population with chronic infections with HCV and HCC.

SUBJECTS AND METHODS

This study was carried out on 40 patients with chronic HCV, 35 patients with hepatocellular carcinoma and 20 healthy persons as control. All subjects were submitted to History taking, clinical examination, abdominal ultrasound, laboratory tests including CBC, liver function tests, alpha fetoprotien, determination of IL17gene polymorphisms by PCR-RFLP, IL17 by ELISA and IgE by immunonephelometric assay.

RESULTS

In reference to AA genotype, the frequencies of GG, GA+GG genotypes in the cases with HCC were significantly different from that of the controls (p=0.012, 0.011) and carry 6.12,4.9 respectively fold increase for HCC risk and that of chronic HCV without HCC (p=0.005, 0.004) respectively. However, there was no significant difference in allele frequency in the studied groups (p=0.095). Cases with HCC significantly have higher levels of serum IL17 and IgE than both healthy control and chronic HCV. In conclusion, the present study showed the GG, GG+GA genotypes of IL17A gene is a risk factor for HCC development may be through increased IL17 and IgE and further studies with larger sample size and different populations are recommended.

Interleukin-21 gene polymorphisms and chronic hepatitis B infection in a Chinese population

AIM: To investigate the relationship between interleukin-21 (IL21) gene polymorphisms and chronic hepatitis B virus (HBV) infection in a Chinese population.

METHODS: In this case-control study, 366 Chinese HBV-infected patients were recruited and divided into hepatocellular carcinoma (HCC; n = 94) and non-HCC (n = 272) groups at The First Affiliated Hospital of Sun Yat-Sen University, from April 2009 to December 2012. In the non-HCC group, the patients were classified into three clinical subsets, 76 patients had chronic hepatitis B, 101 were HBV carriers and 95 patients had HBV-related cirrhosis. Two hundred eight unrelated healthy controls were also included. Genomic DNA was extracted from peripheral blood. Single nucleotide polymorphisms (SNPs) rs13143866, rs2221903, and rs907715 were subsequently genotyped using the SNaPshot SNP technique.

RESULTS: There were no significant differences in allele and genotype frequencies of SNPs rs13143866, rs2221903, and rs907715 between chronic HBV-infected patients and control subjects. Furthermore, no significant differences were found in the frequencies of all alleles and genotypes between the HCC group and the non-HCC group. However, in the subgroup analysis, IL21 rs13143866 genotype AA frequency in the HBV carrier group was higher than in controls (OR = 6.280, 95%CI: 1.238-31.854; P = 0.019), and the effect of the recessive model (AA vs GG + GA, OR = 6.505, 95%CI: 1.289-32.828) was observed in the HBV carrier group. IL21 rs2221903 genotype TC frequency in the HBV carrier group was higher than in controls (OR = 1.809, 95%CI: 1.043-3.139; P = 0.035). In the haplotype analysis, the ATA haplotype (rs13143866, rs2221903, and rs907715) of IL21 was more frequent in the HCC group than in the non-HCC group (0.165 vs 0.104, P = 0.044; OR = 1.700, 95%CI: 1.010-2.863).

CONCLUSION: Genotypes rs13143866 AA and rs2221903 TC are risk factors for carrying HBV; ATA haplotype increases the risk of HBV-related HCC onset in a Chinese population.

CD4+ CXCR5+ T cells in chronic HCV infection produce less IL-21, yet are efficient at supporting B cell responses

BACKGROUND & AIMS

During chronic HCV infection, T cell dependent virus-specific antibodies are produced. However, the role of B-T cell interaction in chronic HCV is largely unknown. CD4(+)CXCR5(+) T follicular helper (TFH)-cells activate B cells and are important for clearance of various chronic viral infections. We investigated the function of TFH cells and B cells in liver and in peripheral blood of chronic HCV patients.

METHODS

T cells from chronic HCV patients and healthy individuals were analysed for expression of CXCR5, PD-1, ICOS, and IL-21 and IFN-γ production by flow cytometry. CD19(+) B cell subpopulations were identified on the basis of CD27 and IgD expression. In order to assess the frequency and function of T cells and B cells in liver follicles, immunohistochemistry was performed for CD3, CXCR5, Bcl6, IL-21, CD20, IgD, IgM, and IgG.

RESULTS

The frequency of IL-21-producing CXCR5(+)CD4(+) T cells in blood was lower in HCV patients compared to healthy individuals (p=0.002), which was reflected by lower serum IL-21 levels (p<0.001). Nonetheless, CXCR5(+)CD4(+) T cells from HCV patients and healthy individuals were equally capable to stimulate CD19(+)CD27(+) memory B cells into IgG and IgM-producing plasmablasts. Importantly, human intrahepatic TFH cells and their related function were identified by immunohistochemistry on liver biopsies for CD3, Bcl6, and CD20 within portal areas and follicles.

CONCLUSIONS

The specific localization of TFH cells and IgG and IgD/IgM-producing B cells suggests a functional B-T cell environment in liver follicles during HCV infection. The decreased frequency of IL-21-producing CXCR5(+)CD4(+) T cells and lower serum IL-21 levels in chronic HCV patients did not lead to an altered TFH-B cell interaction.

Interleukin-21 and T follicular helper cells in HIV infection: research focus and future perspectives

Interleukin (IL)-21 is a member of the γ chain-receptor cytokine family along with IL-2, IL-4, IL-7, IL-9, and IL-15. The effects of IL-21 are pleiotropic, owing to the broad cellular distribution of the IL-21 receptor. IL-21 is secreted by activated CD4 T cells and natural killer T cells. Within CD4 T cells, its secretion is restricted mainly to T follicular helper (Tfh) cells and Th17 cells to a lesser extent. Our research focus has been on the role of IL-21 and more recently of Tfh in immunopathogenesis of HIV infection. This review focuses on first the influence of IL-21 in regulation of T cell, B cell, and NK cell responses and its immunotherapeutic potential in viral infections and as a vaccine adjuvant. Second, we discuss the pivotal role of Tfh in generation of antibody responses in HIV-infected persons in studies using influenza vaccines as a probe. Lastly, we review data supporting ability of HIV to infect Tfh and the role of these cells as reservoirs for HIV and their contribution to viral persistence.

A promoter polymorphism (rs3806798) of interleukin-15 gene is associated with chronic hepatitis B virus infection in the Chinese Han population

This study aimed to investigate the association between the polymorphisms of IL-15 gene and susceptibility to chronic hepatitis B virus (HBV) infection in the Chinese Han population. A total of 234 patients with chronic HBV infection and 150 age- and sex-matched healthy controls in the Chinese population were enrolled in this case-control study. Genotyping of ten single nucleotide polymorphisms (SNPs) in the IL-15 gene was carried out via Sequenom MassARRAY system. The association analysis demonstrated that SNP rs3806798 (A/T) had a significant difference in the distribution between patients and healthy controls (P = 0.033). Moreover, a significantly increased risk of HBV infection was found to be associated with IL-15 rs3806798 A allele among male patients and HBeAg-negative patients, compared with IL-15 rs3806798 T allele (P = 0.003; P = 0.046, respectively). Furthermore, haplotype analysis revealed that haplotype ATAGG (rs3806798, rs12508866, rs1519551, rs6819823 and rs2857261, respectively) in block 1 was significantly associated with HBV infection (P = 0.022). In conclusion, we found an association between IL-15 rs3806798 and the risk of chronic HBV infection in a sample of Chinese Han population.