Role of T-Helper 9 Cells in Chronic Hepatitis C-Infected Patients

The emerging role of T helper 9 (Th9) cells in immunopathophysiology: A comprehensive review of their effects and responsiveness in various disease states

Th9 cells, a subset of T-helper cells producing interleukin-9 (IL-9), play a vital role in the adaptive immune response and have diverse effects in different diseases. Regulated by transcription factors like PU.1 and IRF4, and cytokines such as IL-4 and TGF-β, Th9 cells drive tissue inflammation. This review focuses on their emerging role in immunopathophysiology. Th9 cells exhibit immune-mediated cancer cell destruction, showing promise in glioma and cervical cancer treatment. However, their role in breast and lung cancer is intricate, requiring a deeper understanding of pro- and anti-tumor aspects. Th9 cells, along with IL-9, foster T cell and immune cell proliferation, contributing to autoimmune disorders. They are implicated in psoriasis, atopic dermatitis, and infections. In allergic reactions and asthma, Th9 cells fuel pro-inflammatory responses. Targeting Foxo1 may regulate innate and adaptive immune responses, alleviating disease symptoms. This comprehensive review outlines Th9 cells' evolving immunopathophysiological role, emphasizing the necessity for further research to grasp their effects and potential therapeutic applications across diseases.

Regulatory role of T helper 9/interleukin-9: Transplantation view

T helper 9 (Th9) cells, a subset of CD4+ T helper cells, have emerged as a valuable target for immune cell therapy due to their potential to induce immunomodulation and tolerance. The Th9 cells mainly produce interleukin (IL)-9 and are known for their defensive effects against helminth infections, allergic and autoimmune responses, and tumor suppression. This paper explores the mechanisms involved in the generation and differentiation of Th9 cells, including the cytokines responsible for their polarization and stabilization, the transcription factors necessary for their differentiation, as well as the role of Th9 cells in inflammatory and autoimmune diseases, allergic reactions, and cancer immunotherapies. Recent research has shown that the differentiation of Th9 cells is coregulated by the transcription factors transforming growth factor β (TGF-β), IL-4, and PU.1, which are also known to secrete IL-10 and IL-21. Multiple cell types, such as T and B cells, mast cells, and airway epithelial cells, are influenced by IL-9 due to its pleiotropic effects.

Modulation of Production of Th1/Th2 Cytokines in Peripheral Blood Mononuclear Cells and Neutrophils by Hepatitis C Virus Infection in Chronically Infected Patients

This study investigated the influence of Hepatitis C virus (HCV) infection on the cytokine production profiles of the peripheral blood monoculear cells (PBMC) and neutrophils in chronically naïve HCV-infected patients. Seventy-five genotype-4 naïve HCV-infected patients (HCV+) and healthy subjects (HCV-) were enrolled. The neutrophils and the PBMC were separated by density gradient sedimentation and stimulated with a mitogen. The culture supernatants were evaluated for levels of IFN-α, IFN-γ, IL-2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-12, and TNF-α using anti-cytokine antibody MACSPlex capture beads. The PBMC cytokine profiles of HCV+ patients showed significantly lower mean values for IFN-γ, IL-2, IL-6, IL-9, and IL-10 (p < 0.0001) as compared to HCV- subjects. In contrast, HCV+ patients showed higher mean levels of PBMC cytokine values for IL-5 and TNF-α (p < 0.0001). As for neutrophils, HCV+ patients showed significantly lower mean levels of IFN-α, IFN-γ, IL-2, IL-4, IL-6, IL-9, and IL-10 (p < 0.0001). In contrast, the neutrophils from HCV+ patients showed higher mean levels of IL-5, IL-12, and TNF-α (p < 0.0001). Th1-Th2 cytokine ratios suggested a lower Th1 bias in HCV+ subjects as compared to HCV- subjects. Our results suggest that chronic HCV infection brings about an immunomodulatory effect not only on neutrophils, but also to a lower extent on PBMCs.

Clinical Outcomes and Prevalence of Hepatitis E Virus (HEV) Among Non-A-C Hepatitis Patients in Egypt

Background

Hepatitis E virus (HEV) is an emerging infectious agent that causes acute hepatitis in developing and developed countries. Diagnosis of HEV infection has not been routinely done in Egyptian hospitals, and clinicians do not prescribe ribavirin (RBV) for acute hepatitis cases of unknown etiology (AHUE). We aimed to screen patients with AHUE for the presence of HEV markers and to determine the complications associated with HEV infection.

Patients and Methods

HEV markers (anti-HEV IgM, anti-HEV IgG, and HEV RNA) were assessed in patients with AHUE (n=300) admitted to Assiut University Hospitals. RT-qPCR was used to detect the viral load and sequencing analysis was carried out to determine the genotype of the detected viruses. Phylogenetic tree was constructed to evaluate the genetic relatedness between the isolates. Laboratory parameters and the outcomes of infection were determined.

Results

Acute HEV infection (AHE) was detected in 30 out of 300 (10%) of AHUE patients. Anti-HEV IgM, HEV RNA, and anti-HEV IgG were reported in 83%, 50%, and 43% of the samples, respectively. HEV RNA load ranged from 5×10² IU/mL to 1.1×10⁴ IU/mL. Sequencing of the isolated viruses revealed that five viruses belong to HEV-1 and one isolate belongs to HEV-3 with high homology to the virus recently isolated from the cow and goat milk in the Egyptian villages. Although previous reports showed that attenuated HEV isolates were circulating in Egypt, four out of 30 patients (13%) developed coagulopathy and hepatic encephalopathy and died due to fulminant hepatic failure (FHF) within 3–6 weeks of hospitalization. Age, malignancy, and a history of pre-existing liver diseases were a risky factor for FHF development.

Conclusion

AHE is common in Upper Egypt. Older patients with malignancy and/or a history of liver diseases are risky. HEV diagnosis and treatment become pivotal in Egyptian hospitals to reduce the fatality rate and they should start urgently and promptly.

Immunopathobiology and therapeutic targets related to cytokines in liver diseases

Chronic liver injury with any etiology can progress to fibrosis and the end-stage diseases cirrhosis and hepatocellular carcinoma. The progression of liver disease is controlled by a variety of factors, including liver injury, inflammatory cells, inflammatory mediators, cytokines, and the gut microbiome. In the current review, we discuss recent data on a large number of cytokines that play important roles in regulating liver injury, inflammation, fibrosis, and regeneration, with a focus on interferons and T helper (Th) 1, Th2, Th9, Th17, interleukin (IL)-1 family, IL-6 family, and IL-20 family cytokines. Hepatocytes can also produce certain cytokines (such as IL-7, IL-11, and IL-33), and the functions of these cytokines in the liver are briefly summarized. Several cytokines have great therapeutic potential, and some are currently being tested as therapeutic targets in clinical trials for the treatment of liver diseases, which are also described.

Hepatitis E Virus Mediates Renal Injury via the Interaction between the Immune Cells and Renal Epithelium

Renal disorders are associated with Hepatitis E virus (HEV) infection. Progression to end-stage renal disease and acute kidney injury are complications associated with HEV infection. The mechanisms by which HEV mediates the glomerular diseases remain unclear. CD10+/CD13+ primary proximal tubular (PT) epithelial cells, isolated from healthy donors, were infected with HEV. Inflammatory markers and kidney injury markers were assessed in the presence or absence of peripheral blood mononuclear cells (PBMCs) isolated from the same donors. HEV replicated efficiently in the PT cells as shown by the increase in HEV load over time and the expression of capsid Ag. In the absence of PBMCs, HEV was not nephrotoxic, with no direct effect on the transcription of chemokines (Cxcl-9, Cxcl-10, and Cxcl-11) nor the kidney injury markers (kidney injury molecule 1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and interleukin 18 (lL-18)). While higher inflammatory responses, upregulation of chemokines and kidney injury markers expression, and signs of nephrotoxicity were recorded in HEV-infected PT cells cocultured with PBMCs. Interestingly, a significantly higher level of IFN-γ was released in the PBMCs-PT coculture compared to PT alone during HEV infection. In conclusion: The crosstalk between immune cells and renal epithelium and the signal axes IFN-γ/chemokines and IL-18 could be the immune-mediated mechanisms of HEV-induced renal disorder.

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.

Replication of Hepatitis E Virus (HEV) in Primary Human-Derived Monocytes and Macrophages In Vitro

HEV is the most causative agent of acute viral hepatitis globally. HEV causes acute, chronic, and extrahepatic manifestations. Chronic HEV infection develops in immunocompromised patients such as organ transplant patients, HIV-infected patients, and leukemic patients. The source of chronic HEV infection is not known. Also, the source of extrahepatic manifestations associated with HEV infection is still unclear. Hepatotropic viruses such as HCV and HBV replicate in peripheral blood mononuclear cells (PBMCs) and these cells become a source of chronic reactivation of the infections in allograft organ transplant patients. Herein, we reported that PBMCs and bone marrow-derived macrophages (BMDMs), isolated from healthy donors (n = 3), are susceptible to HEV in vitro. Human monocytes (HMOs), human macrophages (HMACs), and human BMDMs were challenged with HEV-1 and HEV-3 viruses. HEV RNA was measured by qPCR, the marker of the intermediate replicative form (ds-RNA) was assessed by immunofluorescence, and HEV capsid protein was assessed by flow cytometry and ELISA. HEV infection was successfully established in primary HMOs, HMACs, and human BMDMs, but not in the corresponding cells of murine origin. Intermediate replicative form (ds RNA) was detected in HMOs and HMACs challenged with HEV. The HEV load was increased over time, and the HEV capsid protein was detected intracellularly in the HEV-infected cells and accumulated extracellularly over time, confirming that HEV completes the life cycle inside these cells. The HEV particles produced from the infected BMDMs were infectious to naive HMOs in vitro. The HEV viral load was comparable in HEV-1- and HEV-3-infected cells, but HEV-1 induced more inflammatory responses. In conclusion, HMOs, HMACs, and human BMDMs are permissive to HEV infection and these cells could be the source of chronic and recurrent infection, especially in immunocompromised patients. Replication of HEV in human BMDMs could be related to hematological disorders associated with extrahepatic manifestations.

Hepatitis C Virus Affects Tuberculosis-Specific T Cells in HIV-Negative Patients

The occurrence of tuberculosis (TB) and hepatitis C virus (HCV) infections in the same patient presents a unique clinical challenge. The impact of HCV infection on the immune response to TB remains poorly investigated in TB⁺/HCV⁺ patients. This study was conducted to evaluate the impact of HCV on the T-cell-mediated immune response to TB in coinfected patients. Sixty-four patients with active TB infections were screened for coinfection with HCV. The expression of immune activation markers IFN-γ, CD38, and HLA-DR on TB-specific CD4⁺ T cells was evaluated by flow cytometry in TB-monoinfected patients, TB/HCV-coinfected patients, and healthy controls. IL-2, IL-4, IFN-γ, TNF-α, and IL-10 levels were measured using ELISA. The end-of-treatment response to anti-TB therapy was recorded for both patient groups. Significantly lower levels of CD4⁺IFN-γ⁺CD38⁺ and CD4⁺IFN-γ⁺HLA-DR⁺ T cells were detected in TB/HCV-coinfected patients compared to TB monoinfected patients and controls. TB⁺/HCV⁺-coinfected patients showed higher serum levels of IL-10. The baseline frequencies of TB-specific activated T-cell subsets did not predict the response to antituberculous therapy in TB⁺/HCV⁺ patients. We concluded that different subsets of TB-specific CD4⁺ T cells in TB/HCV-infected individuals are partially impaired in early-stage HCV infection. This was combined with increased serum IL-10 level. Such immune modulations may represent a powerful risk factor for disease progression in patients with HCV/TB coinfection.