CCR5 promoter polymorphism influences the interferon response of patients with chronic hepatitis C in Japan

Beyond HIV infection: Neglected and varied impacts of CCR5 and CCR5Δ32 on viral diseases

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CCR5 regulates multiple cell types (e.g., T regulatory and Natural Killer cells) and immune responses.

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The effects of CCR5, CCR5Δ32 (variant associated with reduced CCR5 expression) and CCR5 antagonists vary between infections.

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CCR5 affects the pathogenesis of flaviviruses, especially in the brain.

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The genetic variant CCR5Δ32 increases the risk of symptomatic West Nile virus infection.

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The triad “CCR5, extracellular vesicles and infections” is an emerging topic.

The interactions between chemokine receptors and their ligands may affect susceptibility to infectious diseases as well as their clinical manifestations. These interactions mediate both the traffic of inflammatory cells and virus-associated immune responses. In the context of viral infections, the human C-C chemokine receptor type 5 (CCR5) receives great attention from the scientific community due to its role as an HIV-1 co-receptor. The genetic variant CCR5Δ32 (32 base-pair deletion in CCR5 gene) impairs CCR5 expression on the cell surface and is associated with protection against HIV infection in homozygous individuals. Also, the genetic variant CCR5Δ32 modifies the CCR5-mediated inflammatory responses in various conditions, such as inflammatory and infectious diseases. CCR5 antagonists mimic, at least in part, the natural effects of the CCR5Δ32 in humans, which explains the growing interest in the potential benefits of using CCR5 modulators for the treatment of different diseases. Nevertheless, beyond HIV infection, understanding the effects of the CCR5Δ32 variant in multiple viral infections is essential to shed light on the potential effects of the CCR5 modulators from a broader perspective. In this context, this review discusses the involvement of CCR5 and the effects of the CCR5Δ32 in human infections caused by the following pathogens: West Nile virus, Influenza virus, Human papillomavirus, Hepatitis B virus, Hepatitis C virus, Poliovirus, Dengue virus, Human cytomegalovirus, Crimean-Congo hemorrhagic fever virus, Enterovirus, Japanese encephalitis virus, and Hantavirus. Subsequently, this review addresses the impacts of CCR5 gene editing and CCR5 modulation on health and viral diseases. Also, this article connects recent findings regarding extracellular vesicles (e.g., exosomes), viruses, and CCR5. Neglected and emerging topics in “CCR5 research” are briefly described, with focus on Rocio virus, Zika virus, Epstein-Barr virus, and Rhinovirus. Finally, the potential influence of CCR5 on the immune responses to coronaviruses is discussed.

CCR5 haplotypes influence HCV serostatus in Caucasian intravenous drug users

Background

Up to 90% HIV-1 positive intravenous drug users (IDUs) are co-infected with HCV. Although best recognized for its function as a major co-receptor for cell entry of HIV, CC chemokine receptor 5 (CCR5) has also been implicated in the pathogenesis of HCV infection. Here, we investigated whether CCR5 haplotypes influence HIV-1 and HCV seropositivity among 373 Caucasian IDUs from Estonia.

Methods

Of these IDUs, 56% and 44% were HIV and HCV seropositive, respectively, and 47% were coinfected. 500 blood donors seronegative for HIV and HCV were also evaluated. CCR5 haplotypes (HHA to HHG*2) were derived after genotyping nine CCR2–CCR5 polymorphisms. The association between CCR5 haplotypes with HIV and/or HCV seropositivity was determined using logistic regression analysis. Co-variates included in the models were length of intravenous drug use, HBV serostatus and copy number of CCL3L1, the gene encoding the most potent HIV-suppressive chemokine and ligand for CCR5.

Results

Compared to IDUs seronegative for both HCV and HIV (HCV−/HIV-), IDUs who were HCV+/HIV- and HCV+/HIV+were 92% and 82%, respectively, less likely to possess the CCR5-HHG*1 haplotype, after controlling for co-variates (P_adjusted = 1.89×10⁻⁴ and 0.003, respectively). This association was mostly due to subjects bearing the CCR5 HHE and HHG*1 haplotype pairs. Approximately 25% and<10% of HCV−/HIV- IDUs and HCV−/HIV- blood donors, respectively, possessed the HHE/HHG*1 genotype.

Conclusions

Our findings suggest that HHG*1-bearing CCR5 genotypes influence HCV seropositivity in a group of Caucasian IDUs.

A Study of CC-Chemokine Receptor 5 (CCR5) Polymorphism on the Outcome of HCV Therapy in Egyptian Patients

BACKGROUND

Chronic hepatitis C virus (HCV) infection is a globally serious public health issue.

OBJECTIVES

In this study, we investigated CC chemokine receptor 5 (CCR5-59029) polymorphism which is considered an important component of the immune system in determining the outcome of HCV infection. Its critical role as a marker in response to interferon therapy of HCV infection is also investigated besides its effect on other clinical patient factors.

PATIENTS AND METHODS

This study was conducted on 82 Egyptian patients with chronic Hepatitis C Virus (HCV) infection who received PEG-INF + Ribavirin treatment for 48 weeks. The study was also conducted on 50 healthy controls (with negative results for HCV antibody and RNA PCR). Full history of patients in this study was recorded. Clinical and histological examinations, qualitative HCV nested RT-PCR, quantitative real -time PCR, and genotyping of HCV RNA genome were performed. CCR5-59029 polymorphism with nucleotide substitution from G to A was amplified. The amplicons were digested with restriction endonuclease Bsp 1286I, and produced RFLPs of the CCR5 genotypes were determined.

RESULTS

The present study showed a significant association between the functional SNP of CCR5 gene and the viral response to interferon in chronic HCV Egyptian patients. It was shown that the higher fibrosis stages (F2-F4) had significant association with nonresponse to treatment compared to the lower fibrosis stages (F0-F1) (95% confidence: 5.497 - 55.074, P = 0.0001). In addition, worse liver activity grade (A2-A3) had a very highly significant association with non-responder HCV patients compared to those with better liver activity grade (A1) (95% confidence: 2.242 - 20.974, P = 0.0007). Most importantly HCV patients with G allele had a high significant association with nonresponse to treatment, higher fibrosis stages and worse liver activity grades, while the A allele had a high significant association with sustained response, low fibrosis stages and relatively better liver activity grade (95% confidence: 3.347 - 15.036, P = 0.0001).

CONCLUSIONS

SNPs within the CCR5 gene should be considered as an important factor used in combination with other host gene SNPs when developing a mathematical model for anticipating response to HCV therapy.

Pharmacogenetics of efficacy and safety of HCV treatment in HCV-HIV coinfected patients: significant associations with IL28B and SOCS3 gene variants

BACKGROUND AND AIMS

This was a safety and efficacy pharmacogenetic study of a previously performed randomized trial which compared the effectiveness of treatment of hepatitis C virus infection with pegylated interferon alpha (pegIFNα) 2a vs. 2b, both with ribavirin, for 48 weeks, in HCV-HIV coinfected patients.

METHODS

The study groups were made of 99 patients (efficacy pharmacogenetic substudy) and of 114 patients (safety pharmacogenetic substudy). Polymorphisms in the following candidate genes IL28B, IL6, IL10, TNFα, IFNγ, CCL5, MxA, OAS1, SOCS3, CTLA4 and ITPA were assessed. Genotyping was carried out using Sequenom iPLEX-Gold, a single-base extension polymerase chain reaction. Efficacy end-points assessed were: rapid, early and sustained virological response (RVR, EVR and SVR, respectively). Safety end-points assessed were: anemia, neutropenia, thrombocytopenia, flu-like syndrome, gastrointestinal disturbances and depression. Chi square test, Student's T test, Mann-Whitney U test and logistic regression were used for statistic analyses.

RESULTS

As efficacy is concerned, IL28B and CTLA4 gene polymorphisms were associated with RVR (p<0.05 for both comparisons). Nevertheless, only polymorphism in the IL28B gene was associated with SVR (p = 0.004). In the multivariate analysis, the only gene independently associated with SVR was IL28B (OR 2.61, 95%CI 1.2-5.6, p = 0.01). With respect to safety, there were no significant associations between flu-like syndrome or depression and the genetic variants studied. Gastrointestinal disturbances were associated with ITPA gene polymorphism (p = 0.04). Anemia was associated with OAS1 and CTLA4 gene polymorphisms (p = 0.049 and p = 0.045, respectively), neutropenia and thromobocytopenia were associated with SOCS3 gene polymorphism (p = 0.02 and p = 0.002, respectively). In the multivariate analysis, the associations of the SOCS3 gene polymorphism with neutropenia (OR 0.26, 95%CI 0.09-0.75, p = 0.01) and thrombocytopenia (OR 0.07, 95%CI 0.008-0.57, p = 0.01) remained significant.

CONCLUSIONS

In HCV-HIV coinfected patients treated with PegIFNα and ribavirin, SVR is associated with IL28B rs8099917 polymorphism. HCV treatment-induced neutropenia and thrombocytopenia are associated with SOCS3 rs4969170 polymorphism.

Concordance of CCR5 genotypes that influence cell-mediated immunity and HIV-1 disease progression rates

We used cutaneous delayed-type hypersensitivity responses, a powerful in vivo measure of cell-mediated immunity, to evaluate the relationships among cell-mediated immunity, AIDS, and polymorphisms in CCR5, the HIV-1 coreceptor. There was high concordance between CCR5 polymorphisms and haplotype pairs that influenced delayed-type hypersensitivity responses in healthy persons and HIV disease progression. In the cohorts examined, CCR5 genotypes containing -2459G/G (HHA/HHA, HHA/HHC, HHC/HHC) or -2459A/A (HHE/HHE) associated with salutary or detrimental delayed-type hypersensitivity and AIDS phenotypes, respectively. Accordingly, the CCR5-Δ32 allele, when paired with non-Δ32-bearing haplotypes that correlate with low (HHA, HHC) versus high (HHE) CCR5 transcriptional activity, associates with disease retardation or acceleration, respectively. Thus, the associations of CCR5-Δ32 heterozygosity partly reflect the effect of the non-▵32 haplotype in a background of CCR5 haploinsufficiency. The correlations of increased delayed-type hypersensitivity with -2459G/G-containing CCR5 genotypes, reduced CCR5 expression, decreased viral replication, and disease retardation suggest that CCR5 may influence HIV infection and AIDS, at least in part, through effects on cell-mediated immunity.

Evolution of interferon-based therapy for chronic hepatitis C

Since 1986, interferon-alfa (IFN-α) monotherapy has been administered for patients with chronic hepatitis C (CHC). However, sustained response rate is only about 8% to 9%. Subsequent introduction of ribavirin in combination with IFN-α was a major breakthrough in the treatment of CHC. Sustained virological responses (SVRs) rate is about 30% in hepatitis C virus genotype 1 (HCV-1) patients, and is about 65% in HCV-2 or -3 patients. After 2000, pegylated interferon (PegIFN) much improved the rates of SVR. Presently, PegIFN-α-ribavirin combination therapy has been current standard of care for patients infected with HCV. In patients with HCV-1, treatment for 48 weeks is optimal, but 24 weeks of treatment is sufficient in HCV-2 or -3 infected patients. Clinical factors have been identified as predictors for the efficacy of the IFN-based therapy. The baseline factor most strongly predictive of an SVR is the presence of HCV-2 or -3 infections. Rapid virological response (RVR) is the single best predictor of an SVR to PegIFN-ribavirin therapy. If patients can't achieve a RVR but achieve a complete early virological response (cEVR), treatment with current standard of care can provide more than 90% SVR rate. HCV-1 patients who do not achieve an EVR should discontinue the therapy. Recent advances of protease inhibitor may contribute the development of a novel triple combination therapy.

CCR2-64I allele is associated with the progression of AIDS in a Han Chinese population

It has been reported that the CCR5-Delta32, CCR2-64I and SDF1-3'A polymorphisms have protective effects against HIV-1 infection and can delay the progression of AIDS in European populations. The aim of this study was to investigate the associations of the three loci with HIV-1 infection and the progression of AIDS in the Han population of northern China. We recruited 78 HIV-1-seropositive individuals and 70 population-matched healthy controls from north China. PCR-RFLP was used to genotype these three polymorphisms in all samples. There were no significant differences in the frequencies of any allele between HIV-1-seropositive individuals and healthy controls. In cases, the associations between the three loci and CD4(+) T-lymphocyte counts were not significant; however, there was a significant association between the genotype frequency of CCR2-64I and clinical category (P < 0.05). We have identified a potentially important role of CCR2-64I allele in AIDS progression in the northern Chinese population. Further studies are necessary to clarify the contribution of the CCR2-64I allele to the progression of AIDS for the relatively small sample size.

Chemokine system polymorphisms, survival and hepatocellular carcinoma occurrence in patients with hepatitis C virus-related cirrhosis

AIM: To explore the influence of polymorphisms in genes encoding for the chemokines Stromal cell-Derived Factor-1 (SDF-1)/CXCL12 and Monocyte Chemotactic Protein-1 (MCP-1)/CCL2, or for the chemokine receptor CCR5 on the risks of liver-related death and hepatocellular carcinoma (HCC) occurrence in hepatitis C virus (HCV)-infected patients.

METHODS: SDF-1 3’A, MCP-1 (-2518) and CCR5-Δ32 polymorphisms, SDF-1α, Regulated upon Activation Normal T cells Expressed and Secreted (RANTES)/CCL5 and MCP-1 serum levels were determined in 120 HCV-infected patients, included at time of cirrhosis diagnosis and prospectively followed-up.

RESULTS: During follow-up, 23/120 (19.1%) patients died and 47/120 (39.1%) developed HCC. Carriers and noncarriers of each genetic marker had similar baseline characteristics estimating the severity of liver disease. The occurrence of death or HCC during follow-up was similar among carriers and noncarriers of each polymorphism. There was no association between the carriage of mutated alleles and chemokine serum levels and the latter were not associated with the risks of death or HCC.

CONCLUSION: This study suggests the lack of association of SDF-1 3’A, MCP-1 (-2518), CCR5-Δ32 polymorphisms with death and HCC occurrence in cirrhotic HCV-infected patients.

Diabetes mellitus reduces the therapeutic effectiveness of interferon-alpha2b plus ribavirin therapy in patients with chronic hepatitis C

AIM

Patients with chronic hepatitis C (CHC) often have diabetes mellitus (DM). However, it is unknown whether DM affects patient response to interferon (IFN) plus ribavirin therapy. Therefore, the aim of this study was to examine the influence of DM on the outcome of IFN-alpha2b plus ribavirin therapy.

METHODS

In a cohort of 110 patients with CHC, the outcome of 6 months of IFN-alpha2b plus ribavirin therapy was evaluated by comparing the patients with and without DM.

RESULTS

There were 46 sustained-responders; 64 patients did not become sustained responders. Higher age (P = 0.015), lower platelet counts (P = 0.036), hepatitis C virus (HCV) serotype 1 (P = 0.001), advanced liver fibrosis (P = 0.004), and the presence of DM (P = 0.007) were significantly associated with not becoming a sustained-responder. Seventeen CHC (15%) patients had DM. Sex ratio, age, body mass index, alanine aminotransferase levels, HCV-RNA titer, and HCV serotypes did not significantly differ between the patients with and without DM, while fasting plasma glucose, hemoglobin A1c and liver histological staging were significantly different. On multiple logistic regression analysis, HCV serotype 1 (odds ratio 8.743, 95% confidence interval 2.215-34.517; P = 0.002) and the presence of DM (odds ratio 8.657, 95% confidence interval 1.462-51.276; P = 0.014) were independently associated with not becoming a sustained-responder.

CONCLUSIONS

The findings indicate that DM reduces the response to IFN-alpha2b plus ribavirin therapy in CHC patients.

CCL2-2518 A/G and CCR2 190 A/G do not influence the outcome of hepatitis C virus infection in the Spanish population

AIM: To assess whether CCL2 or interactions between this chemokine and its receptor (CCR2) are associated with outcomes of chronic hepatitis C and with responses to antiviral therapy.

METHODS: Two hundred and eighty-four patients with chronic hepatitis C and 193 non-infected matched controls were included in this study. Patients were categorized according to their Scheuer score of hepatic fibrosis as F0-F2 (n = 202) or F3-F4 (n = 82) and according to their response to anti-Hepatitis C virus (HCV) therapy as sustained response (SR, n = 101) or non-sustained response (NSR, n = 98). Genotyping of the -2518 (A/G) CCL2 was performed using PCR-RFLP, genotyping of the 190 (A/G) CCR2 using a PCR-ARMS system, and genotyping of the rs3138042 (G/A) CCR2 using Taqman probes.

RESULTS: Univariate analyses identified 4 parameters (infection duration time, viral genotype, gender and AST levels) that tended to influence fibrosis and 7 parameters (CCL2G, CCL2ACCR2A, viremia levels, fibrosis stage, viral genotype, infection duration time and AST levels) that significantly influenced or tended to influence response to treatment. Multivariate analysis identified gender and AST levels as parameters that independently influenced fibrosis stage and viral genotype and infection duration time were the two parameters that independently influenced response to treatment.

CONCLUSION: Our results indicate that the mutations studied in the gene pair CCL2/CCR2 do not play a major role in the outcome and response to treatment for HCV infection in the Spanish population.

Assessing Theoretical Risk and Benefit suggested by Genetic Association Studies of CCR5: Experience in a Drug Development Programme for Maraviroc

The proliferation of published gene association studies of the CCR5A32 mutation is of relevance to drug development of a CCR5 antagonist for HIV, in highlighting potential safety concerns. We conducted an initial review of all non-HIV gene association studies of CCR5-Δ32, followed by detailed meta-analyses in the three disease areas most commonly reported. Our review indicated no consistent evidence of increased risk of susceptibility to hepatitis C virus infection or multiple sclerosis among individuals with CCR5-Δ32 mutation, and suggested treatment with a CCR5 inhibitor is unlikely to have related adverse effects. There was, however, evidence to suggest rheumatoid arthritis as a potential therapeutic target for a CCR5 antagonist. Clinical evidence would be required to confirm these findings.

CCR5Δ32 mutation does not influence the susceptibility to HCV infection, severity of liver disease and response to therapy in patients with chronic hepatitis C

AIM: To study whether CCR5Δ32 mutation was associated with viral infection and severity of liver disease.

METHODS: Two hundred and fifty two histologically proven, chronic HCV patients (mean age: 41 ± 14 years; M/F: 164/88) were genotyped. PCR based genotyping of 32 bp deletion at the CCR5 locus was done. Four-hundred and eight matched healthy controls were studied to assess susceptibility to HCV infection. To assess correlation of immune gene polymorphism with severity of HCV related liver disease, patients with chronic HCV infection were divided into those with a fibrosis score of ≤ 2 (mild) or > 2 (severe) and histological activity index (HAI) of ≤ 5 or > 5. For correlation between CCR5Δ32 mutations and response to therapy, 129 patients who completed therapy were evaluated.

RESULTS: The majority (89.4%) of the patients were infected with genotype 3. The frequency of homozygous CCR5Δ32 mutants was comparable to HCV patients as compared to the healthy controls (0.7% vs 0%, P = 0.1). Further more, the frequency of CCR5∆32 mutation was comparable in patients with mild or severe liver disease. (P = NS). There was also no association observed with response to therapy and CCR5Δ32 mutation.

CONCLUSION: CCR5Δ32 mutation does not have a role in disease susceptibility, severity or response to therapy in patients with chronic hepatitis C infection.

Protein therapeutics: new applications for pharmacogenetics

Pharmacogenetic studies have traditionally focused on genes involved in processes that affect the pharmacokinetics of small-molecule drugs, such as drug metabolism. However, attention is shifting to the effects of genetic variations in drug targets and associated pathway components on drug responses. We describe how these variations are important for understanding differences in responses to the growing number of protein therapeutics that are entering clinical practice. Pharmacogenetic studies of these drugs are surveyed, and issues important to the success of such endeavours are discussed. As novel protein therapeutics are introduced, we anticipate that the use of pharmacogenetics will assume a key role in their development and clinical application.