Characteristics of Virology and Immune Inflammation of Epstein-Barr Virus Infection Related Non-Neoplastic Diseases in Children.

BACKGROUND: The goal was to study the difference of virological, immunologic, and inflammatory indicators between Epstein-Barr associated infectious mononucleosis (EBV-IM) and EBV associated hemophagocytic lymphohistiocytosis (EBV-HLH) and to explore the evaluation indicators for monitoring the therapeutic efficacy of EBV-HLH. METHODS: Twenty children with EBV-IM (IM group) and 10 children with EBV-HLH (HLH group) were selected. Virology indicators were detected; the absolute count of lymphocyte, and lymphocyte subsets were detected; the levels of immunoglobulin and ferritin were assayed. RESULTS: Compared to the IM group, the HLH group showed a decrease in EBV-specific VCA-IgM antibody levels (U = 29.0, p = 0.006) and an increase in EBV-specific NA-IgG antibody levels (U = 17.0, p = 0.001), while there was no significant difference in EB-DNA loads (t = 0.417, p = 0.680). The counts of lymphocytes, and various lymphocyte subsets in the HLH group were lower than those in the IM group. Inflammatory markers in the HLH group were significantly higher than those in IM group. Dynamic monitoring of virological, immunological, and inflammatory indicators in HLH patients during treatment showed that EBV DNA gradually decreased in patients with good prognosis. Inflammatory indicators significantly decreased and returned to normal, lymphocyte count significantly increased and returned to normal during treatment. However, patients with poor prognosis showed rebound increase in EBV DNA and inflammatory indicators in the later stage of treatment, while lymphocyte count further decreased with the recurrence of the disease. CONCLUSIONS: Exhausted and damaged immune function in host by persistent stimulation of EB viral antigen is one of the main pathogeneses of EB-HLH. Lymphocyte count and serum ferritin level are effective indicators to monitor the therapeutic efficacy during the treatment to HLH.

Activation of the cGAS-STING pathway by viral dsDNA leading to M1 polarization of macrophages mediates antiviral activity against hepatitis B virus.

BACKGROUND AND AIMS: Activation of the cGAS-STING pathway induces the production of type I interferons, initiating the antiviral immune response, which contributes to the clearance of pathogens. Previous studies have shown that STING agonists promote hepatitis B virus (HBV) clearance; however, few studies have investigated the effect of activating the cGAS-STING pathway in macrophages on HBV. METHODS: The polarization status of HBV particle-stimulated RAW264.7 macrophages was analyzed. After stimulation with HBV particles, the analysis focused on determining whether the DNA sensors in RAW264.7 macrophages recognized the viral double-stranded DNA (dsDNA) and evaluating the activation of the cGAS-STING pathway. Coculture of mouse macrophages and hepatocytes harboring HBV was used to study the antiviral activity of HBV-stimulated RAW264.7 macrophages. RESULTS: After stimulation with HBV particles, HBV relaxed circular DNA (rcDNA) was detected in RAW264.7 macrophages, and the protein expression of phospho-STING, phospho-TBK1, and phospho-IRF3 in the STING pathway was increased, as shown by Western blot analysis, which revealed that M1 polarization of macrophages was caused by increased expression of CD86. RT-PCR analyses revealed elevated expression of M1 macrophage polarization-associated cytokines such as TNFα, IL-1ß, iNOS, and IFNα/ß. In the coculture experiment, both HBsAg and HBeAg expression levels were significantly decreased in AML12-HBV1.3 cells cocultured with the supernatants of HBV-stimulated RAW264.7 macrophages. CONCLUSION: The results suggest that macrophages can endocytose HBV particles. Additionally, viral dsDNA can be recognized by DNA pattern recognition receptors, which in turn activate the cGAS-STING pathway, promoting the M1 polarization of macrophages, while no significant M2 polarization is observed. Macrophages stimulated with HBV particles exhibit enhanced antiviral activity against HBV.

Interferon-induced polarization of M1 macrophages mediates antiviral activity against the hepatitis B virus via the hepcidin-ferroportin axis.

BACKGROUNDS & AIMS: Given its ability to inhibit HBV replication, Interferon alpha (IFN-α) treatment has been confirmed to be effective in managing Chronic Hepatitis B (CHB). However, its underlying mechanisms are incompletely understood. METHODS: Herein, we investigated the antiviral properties of IFN-α by introducing IFN-α expression plasmids into a well-established HBV Hydrodynamic Injection (HDI) mouse model and examined the impact of IFN-α or hepcidin treatment on macrophages derived from THP-1 cells. The cytokine profiles were analyzed using the cytometry microsphere microarray technology, and flow cytometry was used to analyze the polarization of macrophages. Additionally, the IL-6/JAK2/STAT3 signaling pathway and the hepcidin-ferroportin axis were analyzed to better understand the macrophage polarization mechanism. RESULTS: As evidenced by the suppression of HBV replication, injection of an IFN-α expression plasmid and supernatants of IFN-α-treated macrophages exerted anti-HBV effects. The IFN-α treatment up-regulated IL-6 in mice with HBV replication, as well as in IFN-α-treated HepG2 cells and macrophages. Furthermore, JAK2/STAT3 signaling and hepcidin expression was promoted, inducing iron accumulation via the hepcidin-ferroportin axis, which caused the polarization of M1 macrophages. Furthermore, under the effect of IFN-α, IL-6 silencing or blockade downregulated the JAK2/STAT3 signaling pathway and hepcidin, implying that increased hepcidin expression under IFN-α treatment was dependent on the IL-6/JAK2/STAT3 pathway. CONCLUSION: The IL-6/JAK2/STAT3 signaling pathway is activated by IFN-α which induces hepcidin expression. The resulting iron accumulation then induces the polarization of M1 macrophages via the hepcidin-ferroportin axis, yielding an immune response which exerts antiviral effects against HBV replication.