Association of colonic regulatory T cells with hepatitis C virus pathogenesis and liver pathology

Gut virome: New key players in the pathogenesis of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory illness of the intestine. While the mechanism underlying the pathogenesis of IBD is not fully understood, it is believed that a complex combination of host immunological response, environmental exposure, particularly the gut microbiota, and genetic susceptibility represents the major determinants. The gut virome is a group of viruses found in great frequency in the gastrointestinal tract of humans. The gut virome varies greatly among individuals and is influenced by factors including lifestyle, diet, health and disease conditions, geography, and urbanization. The majority of research has focused on the significance of gut bacteria in the progression of IBD, although viral populations represent an important component of the microbiome. We conducted this review to highlight the viral communities in the gut and their expected roles in the etiopathogenesis of IBD regarding published research to date.

Association of TNF-Alpha, MBL2, NOS2, and G6PD with Malaria Outcomes in People in Southern Ghana

Background

One major issue that has set back the gains of the numerous malaria control interventions that national malaria control programs have implemented is asymptomatic malaria. Certain host genetic factors are known to influence symptomatic malaria; however, not much is known about how host genetics influences the acquisition of asymptomatic malaria.

Methods

Genomic DNA was extracted from whole blood collected from 60 symptomatic and 149 nonfebrile (asymptomatic, N = 109, and uninfected, N = 40) volunteers aged between 2 and 69 years from a high (Obom) and a low (Asutsuare) malaria transmission setting in Southern Ghana. Restriction fragment length polymorphism (RFLP) was used to determine polymorphisms at the MBL2 54, TNF-α 308, NOS2 954, and G6PD 202/376 gene loci.

Results

Polymorphisms at the MBL2 54 and TNF-α 308 loci were significantly different amongst the three categories of volunteers in both Asutsuare (p = 0.006) and Obom (p=0.05). In Asutsuare, a low malaria transmission area, the allele G has significantly higher odds (3.15) of supporting asymptomatic malaria as against symptomatic malaria. There were significantly higher odds of TNF-α genotype GA being associated with symptomatic malaria as against asymptomatic malaria in both sites, Obom (p=0.027) and Asutsuare (p=0.027). The allele B of the G6PD gene was more prevalent in symptomatic rather than asymptomatic parasite-infected individuals in both Obom (p=0.001) and Asutsuare (p=0.003).

Conclusion

Individuals in Southern Ghana carrying the TNF-α 308 GA genotype are more likely to exhibit symptoms of malaria when infected with the malaria parasite as opposed to harboring an asymptomatic infection. Also, the B allele of the G6PD gene is likely to prevent a P. falciparum-infected person from exhibiting symptoms and thereby promote asymptomatic parasite carriage.

Impact of interleukin IL-6 rs-1474347 and IL-10 rs-1800896 genetic polymorphisms on the susceptibility of HCV-infected Egyptian patients to hepatocellular carcinoma

Hepatitis C virus (HCV) is considered leading cause of cirrhosis and hepatocellular carcinoma (HCC). We aimed to examine the association of IL-6 and IL-10 single-nucleotide polymorphisms with the progression of chronic HCV (CHC) infection to cirrhosis and HCC. For comparative purposes, four groups were enrolled; chronic HCV group (CHC, n = 22), HCV-related liver cirrhosis group (HCV-LC, n = 22), HCV-related HCC group (HCV-HCC, n = 54), and an apparently healthy control group (controls, n = 48). HCC diagnosis and staging were in concordance to Barcelona Clinic Liver Cancer (BCLC) staging system. IL-6 rs-1474347 and IL-10 rs-1800896 genotyping was performed by allelic (VIC- and FAM-labeled) discrimination method using assay-on-demand TaqMan real-time PCR assays. For IL-6 rs1474347, the AA genotype was more frequent in CHC, HCV-LC, and HCV-HCC compared to controls. Also, the IL-6 rs1474347 AC genotype was favorable for the progression of HCV chronic infection to cirrhosis and HCC. On the other hand, the IL-10 rs1800896 TT genotype was found to be prominent in the HCC group. Additionally, the IL-10 rs180096 TT genotype was favorable for the progression of chronic HCV infection to cirrhosis and HCC. Furthermore, higher levels of AFP were observed in HCC patients with IL-6 rs1474347 AA genotype and HCC patients with IL-10 rs1800896 CC and TT genotypes. Screening for IL-6 rs 1474347 AC genotype and IL-10 rs180096 TT genotype as well as the determination of AFP level showed to be good markers for examining the susceptibility of HCV Egyptian patients to develop cirrhosis and HCC.

Correlation Between Vascular Endothelial Growth Factor and Long-Term Occurrence of HCV-Related Hepatocellular Carcinoma After Treatment with Direct-Acting Antivirals

We aimed to evaluate the correlation between vascular endothelial growth factor (VEGF) and long-term occurrence of hepatocellular carcinoma after HCV treatment with direct-acting antivirals (DAAs) and the HCC stage. Two groups with HCV-related liver cirrhosis and HCC were included: group 1, HCC following DAAs; group 2, HCC did not receive DAAs. The serum level of VEGF and HCC staging was evaluated. The duration between DAAs and HCC was 21.81 ± 11.66 months. Portal vein thrombosis (PVT) was observed more in group 1 (31%). VEGF was relatively elevated in group 1 compared to group 2. HCC patients after DAAs, showed elevated VEGF with frequent PVT.

Distribution of naturally -occurring NS5B resistance-associated substitutions in Egyptian patients with chronic Hepatitis C

Background

NS5B polymerase inhibitors represent the cornerstone of the present treatment of Hepatitis C virus infection (HCV). Naturally occurring substitution mutations to NS5B inhibitors have been recorded. The current study intended to demonstrate possible natural direct acting antiviral (DAA)—mutations of the HCV NS5B region in HCV patients in Minia governorate, Egypt.

Methods

Samples were collected from 27 treatment-naïve HCV patients and 8 non-responders. Out of 27 treatment-naïve patients, 17 NS5B sequences (amino acids 221–345) from treatment-naïve patients and one sample of non-responders were successfully amplified. Nucleotide sequences have been aligned, translated into amino acids, and compared to drug resistance mutations reported in the literature.

Results

NS5B amino acid sequence analysis ensures several novel NS5B mutations existence (more than 40 substitution mutations) that have not been previously documented to be correlated with a resistant phenotype. It was found that K304R (82.4%), E327D and P300T (76.5% each) substitutions were the most distributed in the tested samples, respectively. S282T, the major resistance mutation that induces high sofosbuvir-resistance level in addition to other reported mutations (L320F/C) and (C316Y/N) were not recognized. Q309R mutation is a ribavirin-associated resistance, which was recognized in one strain (5.9%) of genotype 1g sequences. Besides, one substitution mutation (E237G) was identified in the successfully amplified non-responder sample.

Conclusion

Our study showed various combinations of mutations in the analyzed NS5B genes which could enhance the possibility of therapy failure in patients administered regimens including multiple DAA.

Cytotoxic Chemotherapy as an Alternative for Systemic Treatment of Advanced Hepatocellular Carcinoma in Developing Countries

Systemic therapy options nowadays for advanced hepatocellular carcinoma (HCC) are either immunotherapy with immune checkpoint inhibitors or targeted therapy. As the incidence of liver cancer is much higher in developing countries, these new medications are not readily accessible for most of the patients. Cytotoxic chemotherapy agents are more available and affordable in developing countries. We are trying to explore the effectiveness of the newer cytotoxic agents in the systematic treatment for advanced HCC. This is a systematic review of all randomized controlled trials since 1997 that utilized systemic cytotoxic chemotherapy agents in the systemic treatment for advanced HCC using Scopus, PubMed, and Cochrane library up to February 2020. Six randomized trials were found. Different drugs and dosages were used, so it was statistically inappropriate to conduct a meta-analysis. No Phase III trial showed statistically significant overall survival (OS) benefit for cytotoxic chemotherapy, except subgroup analysis of Chinese patients in one study who had leucovorin, fluorouracil, and oxaliplatin (FOLFOX) regimen. There was no significant progression-free survival (PFS) or response rate in the Phase II trials. There are not enough data to infer the actual benefits of systemic cytotoxic chemotherapy in advanced HCC. However, oxaliplatin-based regimens may give feasible results. Health systems with limited access to targeted therapy and immunotherapy agents may use oxaliplatin-based regimens in clinical trials for advanced HCC. These results should be confirmed in multiple future randomized clinical trials.

Kader H, Munawar N, Abdul Rahman S, Elshaer S, Batiha GEIS, Muhammad K. Investigating Virological, Immunological, and Pathological Avenues to Identify Potential Targets for Developing COVID-19 Treatment and Prevention Strategies

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging coronavirus causing respiratory disease commonly known as COVID-19. This novel coronavirus transmits from human to human and has caused profound morbidity and mortality worldwide leading to the ongoing pandemic. Moreover, disease severity differs considerably from individual to individual. Investigating the virology of COVID-19 and immunological pathways underlying its clinical manifestations will enable the identification and design of effective vaccines and potential therapies. In this review, we explore COVID-19 virology, the contribution of the immune system (innate and adaptive) during infection and control of the virus. Finally, we highlight vaccine development and implications of immune system modulation for potential therapeutic interventions to design better therapeutic strategies to guide future cure.

Kader H, Munawar N, Abdul Rahman S, Elshaer S, Batiha GEIS, Muhammad K. Investigating Virological, Immunological, and Pathological Avenues to Identify Potential Targets for Developing COVID-19 Treatment and Prevention Strategies

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging coronavirus causing respiratory disease commonly known as COVID-19. This novel coronavirus transmits from human to human and has caused profound morbidity and mortality worldwide leading to the ongoing pandemic. Moreover, disease severity differs considerably from individual to individual. Investigating the virology of COVID-19 and immunological pathways underlying its clinical manifestations will enable the identification and design of effective vaccines and potential therapies. In this review, we explore COVID-19 virology, the contribution of the immune system (innate and adaptive) during infection and control of the virus. Finally, we highlight vaccine development and implications of immune system modulation for potential therapeutic interventions to design better therapeutic strategies to guide future cure.

Regulatory B Cells and Their Cytokine Profile in HCV-Related Hepatocellular Carcinoma: Association with Regulatory T Cells and Disease Progression

Although regulatory B cells (Bregs) have been proven to play a suppressive role in autoimmune diseases, infections and different tumors, little is known regarding hepatocellular carcinoma (HCC), especially in hepatitis C-related settings. Herein, we analyzed the frequency of circulating Bregs, serum levels of IL-10, IL-35 and B-cell activating factor (BAFF) and investigated their association with regulatory T cells (Tregs) and disease progression in HCV-related HCC. For comparative purposes, four groups were enrolled; chronic HCV (CHC group, n = 35), HCV-related liver cirrhosis (HCV-LC group, n = 35), HCV-related HCC (HCV-HCC group, n = 60) and an apparently healthy control (Control-group, n = 20). HCC diagnosis and staging were in concordance with the Barcelona Clinic Liver Cancer (BCLC) staging system. Analysis of the percentage of Breg cells and peripheral lymphocyte subsets (Treg) was performed by flow cytometry. Serum cytokine levels of IL-10, IL-35 and B-cell activating factor (BAFF) were measured by ELISA. The frequency of Bregs was significantly higher in the HCV-HCC group compared to the other groups and controls. A significant increase was noted in late-HCC versus those in the early stages. The frequency of Bregs was positively correlated with Tregs, serum IL-10, IL-35 and BAFF. In conclusion, Peripheral Bregs were positively correlated with the frequency of Tregs, IL-10, IL-35 and BAFF, and may be associated with HCV-related HCC progression.

T follicular helper and T follicular regulatory cells in colorectal cancer: A complex interplay

Colorectal cancer is considered to be one of the major causes of morbidity and mortality all over the world. T Follicular helper (T_FH) and T follicular regulatory (T_FR) cells are specialized providers of T-cells to help B-cells and shaping germinal centers (GC) response. Recent researches reported a high percentage of T_FH and T_FR in different infectious diseases and certain malignancies. However, their functional role in human colorectal cancer (CRC) is relatively unknown. Furthermore, recent studies show that the interaction of both T_FH cells and T_FR cells are essential to promote several diseases. Under the control of specific cytokines and B-cell lymphoma 6 transcription factor (Bcl-6), the major transcription factor of T_FH cells, T_FH, can expand to the other distinct CD4 + T helper cells (TH1, TH2, and TH17) which exert a different role in the development of CRC. This review aims to discuss these suggested roles of the two-opposite subset of follicular T cells in colorectal cancer immune pathogenesis.

Prognostic impact of toll-like receptors 2 and 4 expression on monocytes in Egyptian patients with hepatocellular carcinoma

Toll-like receptors (TLRs) have a role in chronic inflammation. Still, little is known about the expression of TLRs in hepatocellular carcinoma (HCC). Herein, we tried to assess the prognostic value of TLR2 and TLR4 expression on circulating monocytes in HCC patients and correlate their levels with some clinical, laboratory data, and treatment outcomes. Forty patients with hepatic focal lesions diagnosed radiologically as HCC by triphasic multislice CT pelviabdominal and chest, and in some patients MRI diffusion and 38 age and sex matching healthy controls were enrolled in the study. Subjects were evaluated for liver functions, alpha-fetoprotein (AFP), imaging, response to different treatments, and overall survival. TLR2 and TLR4 expression by monocytes was detected by flow cytometry. The expression of both TLR2 and TLR4 on monocytes was significantly increased in HCC patients than the controls, in patients with more progressive HCC than those with lower progression and in patients with poor response to treatment than patients with better treatment response. Moreover, their levels showed positive correlations with ALT, AST, and AFP and inverse correlations with the overall survival of HCC patients. The results of the current study suggest that increased expression ofTLR2 and TLR4 on peripheral monocytes might reflect the development and progression of HCC and can be used to indicate poor prognosis. In addition, high expression of TLR2 correlated significantly with poor response to treatment, while high expression of both TLR2 and TLR4 were associated with poor survival. Our findings will help to design more studies on the role of TLRs in HCC pathogenesis and prognosis which may provide new therapeutic targets for HCC.

Nanomedicine as a future therapeutic approach for Hepatitis C virus

Hepatitis C virus (HCV) is not easily cleared from the human body and in most cases turned into chronic infection. This chronicity is a major cause of liver damage, cirrhosis and hepatocellular carcinoma. Therefore, immediate detection and treatment of HCV guarantees eradication of the virus and prevention of chronicity complications. Since discovery of HCV in 1989, several emerging treatments were developed such as polyethylene glycol(PEG)-ylated interferon/ribavirin, direct acting antivirals and host targeting antivirals. Despite the progress in anti-HCV therapy, there is still a pressing need of new approaches for affordable and effective drug delivery systems using nanomedicine. In this review, the contribution of nanoparticles as a promising delivery system for HCV immunizing, diagnostic and therapeutic agents are discussed.

Metoclopramide nanoparticles modulate immune response in a diabetic rat model: association with regulatory T cells and proinflammatory cytokines

Background

The inflammatory basis of diabetes mellitus directed the researchers’ attention to the immune system for better management and prevention of complications. Metoclopramide (MCA; the only US Food and Drug Administration-approved for gastroparesis) has the ability to restore immune function through increasing prolactin secretion. This study aimed to test the effect of BSA/MCA nanoparticles (NPs) on modulating immune response.

Methods

BSA/MCA NPs were fabricated by desolvation and evaluated in vitro via measuring loading efficiency, particle size, and surface charge. The selected formula was further evaluated via differential scanning calorimetry and release behavior. Then, NPs were injected into rats (25 mg MCA/kg/week) for 3 weeks to be evaluated histopathologically and immunologically via measuring proinflammatory cytokines, such as IL1β, IL6, and TNFα, in addition to measuring regulatory T-cell frequency.

Results

MCA was successfully loaded on BSA, achieving high encapsulation efficiency reaching 63±2%, particles size of 120–130 nm with good polydispersity, and a negative surface charge indicating that entire positively charged drug was encapsulated inside NPs. Differential scanning calorimetry thermography of selected NPs showed an obvious interaction between components and cross-linking of BSA molecules using glutaraldehyde, resulting in sustained release of MCA (around 50% within 3 days). MCA NPs significantly restored the immune response via decreasing proinflammatory cytokines and increasing regulatory T-cell frequency when compared to control and free MCA (drug not loaded in NPs)-treated groups. Histopathological examination of this MCA NPs-treated group did not show the characteristic lesions of diabetes, and apoptosis nearly disappeared.

Conclusion

BSA/MCA NPs could be considered a new modality for treatment of gastro-paresis, in addition to management of diabetes itself and preventing its complications via an MCA-immunomodulatory effect.

Increased frequency and FOXP3 expression of human CD8+CD25High+ T lymphocytes and its relation to CD4 regulatory T cells in patients with hepatocellular carcinoma

The mechanism of action of CD8⁺CD25^High+FOXP3⁺ T cells in hepatocellular carcinoma (HCC) has not been fully understood. Herein, the role of CD8⁺CD25^High+FOXP3⁺ T cells in HCC was compared with that of CD4⁺CD25^High+FOXP3⁺ regulatory T cells (conventional Tregs). Thirty-five patients with HCC and twenty age and sex-matched healthy adults (controls) were enrolled. The percentage of CD8⁺CD25^High+FOXP3⁺ T cells and conventional Tregs in peripheral blood was measured by flow cytometry. Our results revealed that the percentage of peripheral CD8⁺CD25^High+FOXP3⁺ T cells in HCC patients was significantly higher than controls (P = 0.005). The conventional Tregs showed the same trend with a higher level in HCC than controls (P < 0.0001). FOXP3 expression of CD8⁺CD25^High+ T cells is higher than that of CD8⁺CD25^low+ and CD8⁺CD25^Negative T cells. The percentage of CD8⁺CD25^High+FOXP3⁺ T cells positively correlated with that of conventional Tregs in HCC patients but not in controls. The higher alpha-fetoprotein positively correlated with the higher CD8⁺CD25^High+FOXP3⁺ T cells and conventional Tregs (R2 = 0.481, P < 0.0001 and R2 = 0.249, P = 0.001, respectively). The frequency of both CD8⁺CD25^High+FOXP3⁺ T cells and conventional Tregs was significantly increased in HCC with multiple lesions compared with those with one or two lesions. In conclusion: CD8⁺CD25^High+FOXP3⁺ T cells similar to conventional Tregs might be used as biomarkers of HCC progression. Therapy targeting the peripherally expanded CD8⁺CD25^High+FOXP3⁺ T cells may provide a novel perspective for HCC treatment.

Frequency and Implications of myeloid-derived suppressor cells and lymphocyte subsets in Egyptian patients with hepatitis C virus-related hepatocellular carcinoma

BACKGROUND AND AIM

Myeloid-derived suppressor cells (MDSCs) play a pivotal role in tumor immunity and induction of immune tolerance to a variety of antitumor effectors, including T lymphocytes. Herein, we tried to evaluate the frequency and clinical significance of MDSCs and different lymphocyte subsets in hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC).

METHODS

Four groups were enrolled; chronic HCV (CHC; n = 40), HCV-related liver cirrhosis (n = 40), HCV-related HCC (HCV-HCC; n = 75), and healthy control group (n = 20). The percentage of peripheral lymphocytes subsets and total MDSCs with their main two subsets; monocytic (M-MDSCs) and granulocytic (G-MDSCs) was evaluated by flow cytometry.

RESULTS

The frequency of total MSDCs and M-MDSCs was significantly elevated in HCV-HCC especially patients with advanced stage HCC compared with those with early-stage HCC. The frequency of total MSDCs and M-MDSCs was positively correlated with ALT, AFP, and HCV viral load and negatively correlated with CD8⁺ T-cell frequency. CD4 ⁺ T cells were significantly decreased in HCV-HCC patients. The frequency of CD4 ⁺ T cells and CD8 ⁺ T cells was negatively correlated with AFP and AST, but not with albumin or HCV viral load.

CONCLUSION

Taken together, our data suggest that MDSCs, M-MDSCs, and lymphocyte subsets are associated with the development and progression of HCV-related HCC.

Prevalence and predictors of occult hepatitis C virus infection among Egyptian patients who achieved sustained virologic response to sofosbuvir/daclatasvir therapy: a multi-center study

Background

Occult hepatitis C virus (HCV) infection (OCI) is characterized by the detection of HCV-RNA in non-serum reservoirs, such as peripheral blood mononuclear cells (PBMCs) and/or hepatocytes with undetectable HCV-RNA or antibodies in the serum. In this study, we tried to evaluate the prevalence and possible predictors of OCI in patients who achieved sustained virologic response (SVR) post sofosbuvir/daclatasvir (SOF/DCV) therapy.

Patients and methods

A cross-sectional multicenter study was designed to enroll 1,280 HCV-infected patients who received SOF (400 mg) plus DCV (60 mg) once daily ± ribavirin regimen for 12 weeks and achieved SVR 12 weeks post treatment. They were randomly recruited from three dedicated Egyptian centers for management of HCV. Real-time PCR was performed to detect HCV-RNA in serum and PBMCs and to evaluate the different risk factors pertaining to the existence of OCI.

Results

HCV-RNA was detected in PBMCs of 50 (3.9%) of them. All OCI cases exhibited significant fibrosis score and raised pre-treatment alanine aminotransferase (ALT) levels. Logistic regression analysis comparing OCI with non-OCI revealed that high pre-treatment viral load, raised ALT, advanced fibrosis score, prolonged prothrombin time, low albumin, Child B score, antiviral experienced patients, and raised bilirubin are the most significant predictor for the possibility of OCI presence with Odds Ratio as 7.03, 5.13, 4.4, 2.68, 2.52, 1.9, 1.5, and 1.2, respectively.

Conclusion

In spite of its remote possibility, OCI post SOF/DCV therapy may be present in some cases, and this may entail a re-auditing for the definition of SVR by dual testing in both serum and PBMCs.

Microbial translocation and T cell activation are modified by direct-acting antiviral therapy in HCV-infected patients

BACKGROUND

Microbial translocation from the gut lumen has been involved in the pathogenesis of liver damage in hepatitis C virus (HCV) infection.

AIM

To investigate the impact of direct-acting antiviral treatment on microbial translocation and T-cell activation, in patients with hepatitis C-related liver disease.

METHODS

We enrolled two groups of HCV-infected patients undergoing direct-acting antiviral treatment: patients with fibrosis ≥F3 according to Metavir (Group ≥F3); patients with hepatitis C recurrence after liver transplantation and Metavir ≥F2 (Group Liver Transplantation + ≥F2). All patients were treated with direct-acting antivirals based on ongoing guidelines. Surrogate biomarkers of microbial translocation (plasma concentrations of soluble-CD14, lipopolysaccharide-binding protein and intestinal fatty acid-binding protein) were evaluated at baseline, at first month, at the end of treatment and 3 months later. T-cell activation was measured by expression of CD38+ HLA-DR at the same time points, only in Group ≥F3.

RESULTS

There were 32 patients in Group ≥F3 and 13 in Group LT + ≥F2. At baseline, levels of soluble-CD14 and lipopolysaccharide-binding protein were significantly higher in both groups vs healthy controls. Baseline soluble-CD14 correlated with glutamic-oxalacetic transaminase (r = 0.384, P = 0.009) and glutamic-pyruvic transaminase (r = 0.293, P = 0.05). A significant decrease in plasma levels of surrogate microbial translocation biomarkers was observed during and after treatment in the two groups although values were not normalised. In Group ≥F3, CD38+ HLADR+ T-cell expression was significantly decreased by direct-acting antiviral treatment. Relapsers (9%) showed higher soluble-CD14 levels at baseline.

CONCLUSION

Surrogate microbial translocation markers and T cell activation are increased in HCV-infected patients with liver fibrosis and decrease during direct-acting antiviral treatment.

Identification of IL-10-secreting CD8+CD28-PD-1+ regulatory T cells associated with chronic hepatitis C virus infection

CD8⁺CD28^- regulatory T cells (Tregs) play important roles in chronic viral infections. Programmed death 1 (PD-1) is highly expressed on hepatitis C virus (HCV)-specific CTLs. However, little is known regarding the role of CD8⁺CD28-PD1⁺ T cells in hepatitis C. Herein, we found that the frequency of CD8⁺CD28^-PD1⁺, but not CD8⁺CD28^-PD1^- T cells, correlated with markers of chronic hepatitis C virus (HCV) infection and the response to treatment. Our results showed that CD8⁺CD28-PD1⁺ T cells were significantly elevated in chronic HCV-infected patients and there was a distinct correlation between the frequency of CD8⁺CD28-PD1⁺ T cells and serum levels of HCV RNA. During a 48-week course of treatment with peg-IFN-a2a plus ribavirin, dynamic changes in the frequencies of CD8⁺CD28-PD1⁺ T cells were observed, associated with the virologic response. IL-10 secretion may explain the suppressive function of CD8⁺CD28-PD1⁺ T cells in chronic HCV-infected patients. Overall, our study demonstrates that PD-1 is an important marker of CD8⁺CD28^- Tregs in chronic HCV infection. Thus, the frequency and regulatory function of CD8⁺CD28-PD1⁺ T cells play vital roles in HCV infection and the response to treatment.

Significant correlation between regulatory T cells and vitamin D status in term and preterm labor

BACKGROUND AND AIM

Vitamin D insufficiency and deficiency have been associated with an increased risk of adverse pregnancy outcomes. Also, vitamin D is known to play a role in promoting the function of regulatory T-cells (Tregs). Tregs play an important role in suppressing the immune response during pregnancy. Our study aimed to investigate Tregs phenotypes in preterm and tem laboring women and its association with vitamin D level.

METHODS

This cross-sectional study included 82 pregnant women, divided into 46 term and 36 preterm laboring women in addition to 30 healthy non-pregnant women. The percentage of CD4⁺CD25⁺Foxp3⁺Treg cells and their composition of four different Treg subsets were evaluated using flow cytometric analysis. Also, serum vitamin D levels were measured by ELISA.

RESULTS

The percentage of the CD4⁺ CD25⁺ FoxP3⁺ Tregs were significantly decreased in term and preterm laboring women compared to the non-pregnant controls. The percentage of CD45RA⁺ Tregs, was significantly increased in term laboring women than preterm laboring women and non-pregnant women. Also, term labor women had increased proportion of HLA-DR^highTregs. Preterm labor women had significant increased proportion of HLA-DR^negative Tregs compared to term labor women. The overall prevalence of vitamin D deficiency and vitamin D insufficiency was higher in preterm than term laboring women and non-pregnant women. Significant positive correlations were found between serum level of 25 (OH)D and percentage of CD4⁺ CD25⁺ Foxp3⁺Tregs and percentage HLA-DR^highTregs among term and preterm laboring women with vitamin D deficiency.

CONCLUSION

There is a strong association between the percentage of Treg phenotypes and vitamin D level in term and preterm labor women with vitamin D deficiency. Also, the onset of term and preterm labor is associated with changes in the composition of the total Treg pool with different Treg subsets which in turn may be responsible for immunologic mechanisms that associated with labor induction.

Contradictory intrahepatic immune responses activated in high-load hepatitis C virus livers compared with low-load livers

We found a HLA class II histocompatibility antigen gene, DQ alpha 1 chain (HLA-DQA1), that was expressed more than 9-fold higher in high-load hepatitis C virus (HCV) livers than low-load HCV livers using transcriptomics of chronic HCV-infected livers. To further investigate this finding, we examined which cells were positive for HLA-DQA1 and what liver immune responses were different between HCV-high and -low livers. HLA-DQA1-positive cells were significantly increased in the HCV-high group, and most positive cells were identified as non-parenchymal sinusoid cells and lymphocytic infiltrates in the portal area. Parenchymal hepatocytes were negative for HLA-DQA1. HLA-DQA1-positive cells in the liver sinusoid were positive for CD68 (macrophages or Kupffer cells); those in the lymphocytic infiltrates were positive for CD20 (B cells) or CD3 (T cells). mRNA levels of antigen-presenting cell (APC) markers such as CD68 and CD11c were significantly upregulated in the HCV-high group and were correlated with HLA-DQA mRNA levels. CD8B mRNA (CD8⁺ T cells) was upregulated in both HCV-positive livers compared with HCV-negative livers, whereas CD154 mRNA (CD4⁺ T helper cell) was upregulated in the HCV-high group compared with the HCV-low group. The immune regulatory molecules FOXP3 mRNA (regulatory T cell, T reg) and programmed cell death ligand-1 (PD-L1) mRNA were significantly increased in the HCV-high group. HCV-high livers had two molecular immune responses: increased APC numbers and adaptive immunity and the induction of immune tolerance. The local hepatic imbalance of contradictory immune responses might be responsible for high HCV loads.

Association between IL28B rs12979860 single nucleotide polymorphism and the frequency of colonic Treg in chronically HCV-infected patients

The IL28B gene is associated with spontaneous or treatment-induced HCV viral clearance. However, the mechanism by which the IL28B single nucleotide polymorphism (SNP) affects the extra-hepatic HCV immune responses and its relationship to HCV pathogenesis have not been thoroughly investigated. To examine the mechanism by which IL28B affects HCV clearance. Forty Egyptian patients with chronic HCV infection receiving an Interferon/ribavirin treatment regimen were enrolled into this study. There were two groups: non-responders (NR; n = 20) and sustained virologic responders (SVR; n = 20). The initial plasma HCV viral loads prior to treatment and IL28B genotypes were determined by quantitative RT-PCR and sequencing, respectively. Liver biopsies were examined to determine the inflammatory score and the stage of fibrosis. Colonic regulatory T cell (Treg) frequency was estimated by immunohistochemistry. No significant association between IL28B genotypes and response to therapy was identified, despite an odds ratio of 3.4 to have the TT genotype in NR compared to SVR (95 % confidence interval 0.3-35.3, p = 0.3). Patients with the TT-IL28Brs12979860 genotype (unfavorable genotype) have significantly higher frequencies of colonic Treg compared to the CT (p = 0.04) and CC (p = 0.03) genotypes. The frequency of colonic Treg cells in HCV-infected patients had a strong association with the IL-28B genotype and may have a significant impact on HCV clearance.

Extra-hepatic infection of hepatitis C virus in the colon tissue and its relationship with hepatitis C virus pathogenesis

Extra-hepatic compartments might contribute to hepatitis C virus (HCV) persistence and extra-hepatic manifestations. Therefore, we investigated HCV infection in colonic tissue in patients with chronic hepatitis C (CHC) and its relationship with HCV pathogenesis. Colonic biopsies were collected from three groups with CHC infection: treatment naïve (TN; n=12), non-responders (NR; n=10) to anti-HCV therapy (pegylated interferon-α and ribavirin) and sustained virologic response (SVR; n=10) and from a fourth healthy control group (n=10). Liver biopsies were examined to assess inflammation and fibrosis. HCV infection and colonic T regulatory (Treg) frequency were detected by immunohistochemistry. HCV core and NS3 proteins were detected in B cells and macrophage/monocytes of 42 % and 25 % of TN and 50 % and 30 % of NR, respectively, but not in SVR or control group. The numbers of cells expressing HCV proteins were positively correlated with both HCV viral load and colonic Treg frequency. A significant negative correlation between HCV-expressing cells with both liver inflammation and fibrosis was identified. Our study provides evidence that HCV can infect B cells and macrophages of the colon. The correlations between HCV infection in colonic tissue and HCV viral load and liver pathology underline the significance of this extra-hepatic infection in HCV pathogenesis and response to therapy.

Toll-Like Receptor 2 Modulates the Balance of Regulatory T Cells and T Helper 17 Cells in Chronic Hepatitis C

Regulatory T cells (Tregs) and interleukin-17-producing T helper (Th17) cells were mutually antagonistic in the pathogenesis of chronic hepatitis C virus (HCV) infection. However, the regulation of imbalance between Tregs and Th17 cells was poorly understood in HCV infection. A recent report revealed the immunomodulatory role of Toll-like receptor (TLR) 2 in regulating the balance of Tregs/Th17 functions in multiple sclerosis. Thus, the aim of the current study was to assess the effect of TLR2 stimulation on the suppressive function of Tregs and Th17 differentiation in chronic hepatitis C. A total of 65 patients with chronic hepatitis C receiving pegylated interferon-a2a and ribavirin therapy for 48 weeks, as well as 20 of normal controls (NCs) were enrolled. Cellular proliferation and cytokine production was tested in purified CD4(+)CD25(+)CD127(dim/-) Tregs in response to the stimulation of Pam3Csk4, an agonist of TLR2. In treatment-naive patients, Tregs, but not Th17 cells, from chronic hepatitis C patients expressed higher levels of TLR2 compared with NCs. Stimulation with Pam3Csk4 enhanced the suppressive function of Tregs and production of IL-10 in chronic hepatitis C more than in NCs. However, TLR2 stimulation did not promote Th17 differentiation of Tregs in chronic hepatitis C patients. Moreover, effective anti-HCV therapy resulted in the induction of IL-17-secreting phenotypic shift of Tregs without loss of inhibitive function upon TLR2 stimulation. These data provided a novel mechanism underlying modulating the balance of Tregs/Th17 cells in chronic hepatitis C. HCV infection shifted Tregs/Th17 cells through TLR2 stimulation by inducing Tregs to produce IL-10 and enhancing inhibitive function of effector T cells, resulting in viral persistence.

Association of interleukin4 gene polymorphisms of recipients and donors with acute rejection following living donor liver transplantation

BACKGROUND

Little is known as to whether the interleukin4 (IL4) gene polymorphisms in recipients or donors affect the incidence of acute cellular rejection (ACR) following living donor liver transplantation (LDLT). Therefore, we determined the effect of IL4 T-33C polymorphisms in recipients and donors on ACR in a large cohort of patients that underwent LDLT.

METHODS

We examined 155 LDLT cases treated at Nagoya University or Kyoto University, Japan, between 2004 and 2009. IL4 T-33C polymorphisms were analyzed in recipients and donors.

RESULTS

Forty-seven recipients (30.3%) developed early ACR. The genotype frequency of IL4 T-33C in the recipients was associated with ACR incidence (P=0.008, P<0.0125 considered significant). Patients with the IL4-33C carrier genotype (C/C or C/T) were significantly associated with a higher incidence of ACR relative to those with the T/T genotype (OR=3.27, 95% CI: 1.56-6.88, P=0.002). The genotype frequencies of IL4 T-33C in the donors were not associated with rejection incidence. In addition, there was no significant effect of IL4 T-33C genotype combinations on ACR incidence in donors and recipients.

CONCLUSIONS

Genotyping of IL4 T-33C in recipients might be useful to stratify the liver transplant recipients according to their risk of ACR.