Single nucleotide polymorphisms of CXCL9-11 chemokines are associated with liver fibrosis in HIV/HCV-coinfected patients

Role of chemokine-like factor 1 as an inflammatory marker in diseases

Immunoinflammatory mechanisms have been incrementally found to be involved in the pathogenesis of multiple diseases, with chemokines being the main drivers of immune cell infiltration in the inflammatory response. Chemokine-like factor 1 (CKLF1), a novel chemokine, is highly expressed in the human peripheral blood leukocytes and exerts broad-spectrum chemotactic and pro-proliferative effects by activating multiple downstream signaling pathways upon binding to its functional receptors. Furthermore, the relationship between CKLF1 overexpression and various systemic diseases has been demonstrated in both in vivo and in vitro experiments. In this context, it is promising that clarifying the downstream mechanism of CKLF1 and identifying its upstream regulatory sites can yield new strategies for targeted therapeutics of immunoinflammatory diseases.

Regulation and functional roles of chemokines in liver diseases

Inflammation is a major contributor to the pathogenesis of almost all liver diseases. Low-molecular-weight proteins called chemokines are the main drivers of liver infiltration by immune cells such as macrophages, neutrophils and others during an inflammatory response. During the past 25 years, tremendous progress has been made in understanding the regulation and functions of chemokines in the liver. This Review summarizes three main aspects of the latest advances in the study of chemokine function in liver diseases. First, we provide an overview of chemokine biology, with a particular focus on the genetic and epigenetic regulation of chemokine transcription as well as on the cell type-specific production of chemokines by liver cells and liver-associated immune cells. Second, we highlight the functional roles of chemokines in liver homeostasis and their involvement in progression to disease in both human and animal models. Third, we discuss the therapeutic opportunities targeting chemokine production and signalling in the treatment of liver diseases, such as alcohol-associated liver disease and nonalcoholic steatohepatitis, including the relevant preclinical studies and ongoing clinical trials.

Study of CXCL9-11 gene polymorphisms in liver fibrosis among patients with chronic hepatitis C

Several factors are associated with the progression of chronic hepatitis C: comorbidities, lifestyle, and pathogenic factors, including immune response, apoptosis and heredity. Single nucleotide polymorphisms (SNPs) in the PNPLA3 and TM6SF2 genes are more widely studied genetic risk factors, while CXCL9-11 chemokines produced by hepatocytes in the process of infection are less well studied. Our aim was to evaluate the influence of CXCL9 rs10336, CXCL10 rs3921 and CXCL11 rs4619915 in liver fibrosis when analysed together with PNPLA3 rs738409 and TM6SF2 rs58542926. The study included 219 patients with chronic hepatitis C. SNP genotyping was performed by real-time PCR. Univariate and multivariate analyses were used to detect the association between SNPs and advanced fibrosis in a recessive genetic model. All SNPs had a minimum allele frequency >5%, and CXCL9 rs10336, CXCL10 rs3921 and CXCL11 rs4619915 were in high linkage disequilibrium (D' ≥ 0.84). In the multivariate analysis, we observed that male gender (P = 0.000), older age (P = 0.025), moderate to intense inflammatory activity (P = 0.002), moderate to accentuated hepatic steatosis (P = 0.026) and the CT genotype of the TM6SF2 rs58542926 SNP (P = 0.014) presented significant associations with advanced fibrosis. Overall, the CXCL9 rs10336, CXCL10 rs3921, CXCL11 rs4619915 and PNPLA3 rs738409 SNPs did not influence liver fibrosis among patients with chronic hepatitis C.

Association between CXCL9/10 polymorphisms and acute rejection of liver allograft

While increased serum concentrations of CXCL9/10 are associated with acute cellular rejection (ACR) occurrence, the association between CXCL9/10 single nucleotide polymorphisms (SNPs) and ACR after liver transplantation (LT) remains unknown.In the present case-control study, polymorphisms of CXCL9 (rs10336) and CXCL10 (rs3921) were determined by polymerase chain reaction in 215 liver transplant recipients. ACR was defined as biopsy proven within 6 months after LT. As selected SNPs were in 3'-UTR region, their possible association with protein synthesis was assessed by measuring the plasma concentration of CXCL9/10 in a cohort of 40 new transplant patients using ELISA.There was no association between CXCL9/10 genotypes and overall incidence of ACR. However, patients with CXCL9 genotype AA developed ACR earlier than patients with GG genotype (P = .003), with similar results for CXCL10 gene (CC vs GG; P = .005). There was no statistically significant difference in plasma concentrations of CXCL9/10 between the rejectors and the non-rejectors. Of note, patients with AA CXCL9 genotype had significantly higher CXCL9 plasma concentrations than patients with AG (P = .01) or GG genotype (P = .045).In conclusion, the SNPs of CXCL9 (rs10336) and CXCL10 (rs3921) are not associated with the incidence of ACR. However, patients with CXCL9 genotype AA developed ACR earlier and the same genotype was associated with greater plasma concentrations suggesting the involvement of CXCL9 mediated processes in ACR development.

Association of CXCR2 genotype variations with HCV clearance in a Chinese population

Chemokines are known to play a vital role in guiding and regulating the immune response to viral infections. The chemokine CXC subfamily is a major subfamily in the chemokine family. Outcomes of hepatitis C virus (HCV) infection, as well as the response to treatment, depend on virus and host factors. Here we recruited chronic hepatitis C (CHC) patients to perform an association study between three single nucleotide polymorphisms (SNPs) (CXCR2 rs1126579, CXCL10 rs8878 and CXCL10 rs3921) and HCV infection outcomes and treatment responses among a Chinese population, using primarily a TaqMan assay. Multivariate logistic regression analysis was performed to identify the influencing factors on HCV infection outcome and treatment response. The results showed that subjects with the CXCR2 rs1126579 TT genotype had a significantly increased possibility of HCV spontaneous clearance (Dominant model: adjusted OR = 1.32, 95% CI = 1.06-1.64; P = 0.013). Additionally, CHC patients carrying the CXCR2 rs1126579 TT genotype were also more likely to achieve a sustained virological response (SVR) (Dominant model: adjusted OR = 0.49, 95% CI = 0.29-0.84; P = 0.010). We also established a predictive model for HCV treatment response including the CXCR2 rs1126579 SNP status, albumin (ALB) levels and baseline HCV RNA levels, which produced an area under the curve (AUC) of about 0.660. These findings highlight that variant CXCR2 rs1126579 genotypes are associated with HCV clearance within the Chinese population.

Genetic variants in chemokine CC subfamily genes influence hepatitis C virus viral clearance

Chemokine genes may influence both hepatitis C virus (HCV) spontaneous clearance in acute infection and treatment response in chronic infection. We conducted this study to evaluate whether the genetic variants in several CC family genes influence HCV spontaneous clearance and treatment response. The current research genotyped eight SNPs, including CCR1 rs3733096, rs13096371, CCR5 rs746492, rs1800874, CCL3 rs1130371, CCL5 rs3817656, CCL8 rs1133763, CCL14 rs854625, to explore their associations with HCV spontaneous clearance and response to treatment in two populations. We identified that the CCR1 rs3733096 (dominant model: adjusted OR = 2.29, 95% CI = 1.49-3.53, additive model: adjusted OR = 2.21, 95% CI = 1.50-3.25) and CCL5 rs3817656 (dominant model: OR = 1.37, 95% CI = 1.10-1.70, additive model: OR = 1.33, 95% CI = 1.12-1.58) were associated with HCV spontaneous clearance in Chinese Han population, while we found no association with treatment response. Moreover, the expression quantitative trait loci (eQTL) analysis showed that the risk alleles of rs3817656 were significantly associated with downregulated expression of CCL5 in whole blood (P < 0.001). The polymorphism of CCR1 rs3733096 and CCL5 rs3817656 are associated with spontaneous clearance of HCV in Chinese Han population.

Polymorphisms of chemokine receptor genes and clearance of hepatitis C virus infection in Chinese population

BACKGROUND

Chemokine genes play an essential role in both spontaneous clearance in acute infection and therapy of HCV. We investigated whether several CXC family-related genes associated with HCV spontaneous clearance and response to treatment.

METHODS

The current study genotyped four SNPs, respectively are CXCR6 rs2234358, CXCL12 rs1801157, CXCL9 rs10336, rs3733236 to assess their associations with HCV spontaneous clearance and response to treatment in a two stage study (668 chronic and 400 resolvers in discovery group, meanwhile 333 chronic and 199 resolver in replication group), and a treatment cohort of HCV with 282 patients.

RESULTS

We found that the CXCR6 rs2234358 was associated with HCV spontaneous clearance in Chinese Han population (dominant model: adjusted OR=1.62, 95%CI: 1.30-2.01; additive model: adjusted OR=1.43, 95%CI: 1.20-1.70). Patients carrying GT/TT genotypes had increased sustained virological response compared with patients carrying the GG genotype (dominant model: adjusted OR=2.23, 95%CI: 1.26-3.95).

CONCLUSION

These results suggest that CXCR6 rs2234358 is associated with spontaneous clearance of HCV and response to IFN-α/RBV therapy, which may be identified as a predictive marker in Chinese Han population of HCV.

CXCL9-11 polymorphisms are associated with liver fibrosis in patients with chronic hepatitis C: a cross-sectional study

Background and aims

CXCL9-11 polymorphisms are related to various infectious diseases, including hepatitis C virus (HCV) infection. In this study, we analyzed the association between CXCL9-11 polymorphisms and liver fibrosis in HCV-infected patients.

Methods

We performed a cross-sectional study in 389 patients who were genotyped for CXCL9-11 polymorphisms (CXCL9 rs10336, CXCL10 rs3921, and CXCL11 rs4619915) using the Sequenom’s MassARRAY platform. The primary outcome variable was the liver stiffness measurement (LSM). We established three cut-offs of LSM: LSM ≥ 7.1 kPa (F ≥ 2—significant fibrosis), LSM ≥ 9.5 kPa (F ≥ 3—advanced fibrosis), and LSM ≥ 12.5 kPa (F4—cirrhosis).

Results

Recessive, overdominant and codominant models of inheritance showed significant values, but the overdominant model was the best fitting our data. In this case, CXCL9 rs10336 AG, CXCL10 rs3921 CG and CXCL11 rs4619915 AG were mainly associated with lower values of LSM [(adjusted GMR (aGMR) = 0.85 (p = 0.005), aGMR = 0.84 (p = 0.003), and aGMR = 0.84 (p = 0.003), respectively]. Patients with CXCL9 rs10336 AG genotype had lower odds of significant fibrosis (LSM ≥ 7.1 kPa) [adjusted OR (aOR) = 0.59 (p = 0.016)], advanced fibrosis (LSM ≥ 9.5 kPa) [aOR = 0.54 (p = 0.010)], and cirrhosis (LSM ≥ 12.5 kPa) [aOR = 0.56 (p = 0.043)]. Patients with CXCL10 rs3921 CG or CXCL11 rs4619915 AG genotypes had lower odds of significant fibrosis (LSM ≥ 7.1 kPa) [adjusted OR (aOR) = 0.56 (p = 0.008)], advanced fibrosis (LSM ≥ 9.5 kPa) [aOR = 0.55 (p = 0.013)], and cirrhosis (LSM ≥ 12.5 kPa) [aOR = 0.57 (p = 0.051)]. Additionally, CXCL9-11 polymorphisms were related to lower liver stiffness under a codominant model of inheritance, being the heterozygous genotypes also protective against hepatic fibrosis. In the recessive inheritance model, the CXCL9 rs10336 AA, CXCL10 rs3921 CC and CXCL11 rs4619915 AA were associated with higher LSM values [(adjusted GMR (aGMR) = 1.19 (p = 0.030), aGMR = 1.21 (p = 0.023), and aGMR = 1.21 (p = 0.023), respectively]. Moreover, patients with CXCL9 rs10336 AA genotype had higher odds of significant fibrosis (LSM ≥ 7.1 kPa) [adjusted OR (aOR) = 1.83 (p = 0.044)] and advanced fibrosis (LSM ≥ 9.5 kPa) [aOR = 1.85 (p = 0.045)]. Furthermore, patients with CXCL10 rs3921 CC or CXCL11 rs4619915 AA genotypes had higher odds of advanced fibrosis (LSM ≥ 9.5 kPa) [aOR = 1.89 (p = 0.038)].

Conclusions

CXCL9-11 polymorphisms were related to likelihood of having liver fibrosis in HCV-infected patients. Our data suggest that CXCL9-11 polymorphisms may play a significant role against the progression of CHC and could help prioritize antiviral therapy.

Coding and non-coding gene regulatory networks underlie the immune response in liver cirrhosis

Liver cirrhosis is recognized as being the consequence of immune-mediated hepatocyte damage and repair processes. However, the regulation of these immune responses underlying liver cirrhosis has not been elucidated. In this study, we used GEO datasets and bioinformatics methods to established coding and non-coding gene regulatory networks including transcription factor-/lncRNA-microRNA-mRNA, and competing endogenous RNA interaction networks. Our results identified 2224 mRNAs, 70 lncRNAs and 46 microRNAs were differentially expressed in liver cirrhosis. The transcription factor -/lncRNA- microRNA-mRNA network we uncovered that results in immune-mediated liver cirrhosis is comprised of 5 core microRNAs (e.g., miR-203; miR-219-5p), 3 transcription factors (i.e., FOXP3, ETS1 and FOS) and 7 lncRNAs (e.g., ENTS00000671336, ENST00000575137). The competing endogenous RNA interaction network we identified includes a complex immune response regulatory subnetwork that controls the entire liver cirrhosis network. Additionally, we found 10 overlapping GO terms shared by both liver cirrhosis and hepatocellular carcinoma including “immune response” as well. Interestingly, the overlapping differentially expressed genes in liver cirrhosis and hepatocellular carcinoma were enriched in immune response-related functional terms. In summary, a complex gene regulatory network underlying immune response processes may play an important role in the development and progression of liver cirrhosis, and its development into hepatocellular carcinoma.

Short Communication: Few Liver-Infiltrating Cells Express CXCR3 in HIV/HCV Patients Commencing Antiretroviral Therapy

Coinfections with Hepatitis C virus and human immunodeficiency virus accelerate the progression of both conditions and hamper effective treatment. Here we describe expression of CXCR3 on liver-infiltrating cells and peripheral T cells from coinfected patients commencing antiretroviral therapy (ART) in Indonesia. CXCR3 was expressed by small number of intrahepatic inflammatory cells, mostly in the portal areas. The number of cells did not change on ART and was markedly lower than the number of CD4⁺ and CD8⁺ cells in the liver. Data suggest that CXCR3 may contribute to liver infiltration but demonstrate a dynamic situation, changing as the immune system recovers on ART.