Clearance of HBeAg and HBsAg of HBV in mice model by a recombinant HBV vaccine combined with GM-CSF and IFN-α as an effective therapeutic vaccine adjuvant

Increased Th17 and Treg levels in peripheral blood positively correlate with minimal residual disease in acute myeloid leukaemia

PURPOSE

Immune dysregulation plays a key role in acute myeloid leukemia (AML). We aimed to explore the correlation between T helper cell 17 (Th17) and the regulatory cells (Tregs) in the peripheral blood of patients with newly diagnosed (ND) AML and bone marrow blast cells, as well as minimal residual disease (MRD) before and after treatment.

METHODS

Changes in Th17 and Treg cells in the peripheral blood of 32 patients with ND AML were observed before and after induction chemotherapy with cytarabine for seven days and anthracycline for three days. The levels of inflammatory cytokines were measured using an enzyme-linked immunosorbent assay. Correlation analysis between bone marrow blast cells and Th17 and Treg cell frequencies was performed using the Pearson's correlation test. Frequencies of Th17 and Treg cells and MRD were assessed using flow cytometry.

RESULTS

IL-6, IL-10, IL-17A, and GM-CSF levels gradually increased in patients with ND AML and CR and NR patients. The percentages of Th17 and Treg cells positively correlated with those of blast cells. In addition, the frequencies of Th17 and Treg cells in MRD-positive patients were higher than those in MRD-negative patients at the initial induction and after three months of chemotherapy. The frequencies of Tregs and Th17 cells positively correlated with MRD onset.

CONCLUSION

Increased Th17 and Treg cell levels were positively correlated with onset of AML, poor remission, and MRD.

Recombinant porcine interferon cocktail delays the onset and lessens the severity of African swine fever

African swine fever (ASF) is a highly contagious and deadly disease that affects domestic and wild pigs. No commercial vaccine or antiviral is currently available against ASF. The control of ASF primarily relies on implementing effective biosecurity measures during the breeding process. Here, we evaluated the preventive and therapeutic potential of the interferon (IFN) cocktail (a mixture of recombinant porcine IFN α and γ) on ASF. The IFN cocktail treatment delayed the onset of ASF symptoms and ASF virus (ASFV) replication for approximately one week. However, IFN cocktail treatment could not prevent the death of the pigs. Further analysis showed that IFN cocktail treatment increased the expression of multiple IFN-stimulated genes (ISGs) in porcine peripheral blood mononuclear cells in vivo and in vitro. Additionally, IFN cocktail modulated the expression of pro- and anti-inflammatory cytokines and reduced tissue injury in the ASFV-infected pigs. Collectively, the results suggest that the IFN cocktail restricts the progression of acute ASF by inducing high levels of ISGs, contributing to the pre-establishment of antiviral status, and modulating the balance of pro- and anti-inflammatory mediators to lessen cytokine storm-mediated tissue damage.

Mafosfamide Boosts GMI-HBVac against HBV via Treg Depletion in HBV-Infected Mice

Chronic hepatitis B infection remains a significant worldwide health burden, placing persons at risk for hepatocellular cancer and hepatic fibrosis. Chronic hepatitis B virus (CHB) infection is characterized by elevated levels of immunosuppressive regulatory T cells (Tregs), which can inhibit the function of effector T cells and lead to an insufficient immune clearance response against HBV. Theoretically, suppression of Treg cell functionality and percentage could increase anti-HBV reactivity in CHB-infected patients, although this has not yet been explored. We attempted to enhance our previously established anti-CHB protocol utilizing the GM-CSF+IFN-α+rHBVvac regimen (GMI-HBVac) by incorporating mafosfamide (MAF), which has been utilized in anticancer therapy in the past. Intravenous administration of MAF to rAAV8-1.3HBV-infected mice resulted in a dose-dependent reduction of Tregs in the blood, rebounding to pretreatment levels 10 days later. To assess the potential benefit of adding MAF to the anti-CHB protocol, 2 μg/mL MAF was combined with the GMI-HBVac as an anti-Treg treatment in an HBV-infected animal model. When rAAV8-1.3HBV-infected mice were immunized with MAF+GMI-HBVac, peripheral blood Tregs decreased significantly, leading to dendritic cell activation, HBV-specific T cell proliferation, and the upregulation of IFN-gamma-producing CD8⁺T cells. In addition, MAF+GMI-HBVac vaccination stimulated T cell infiltration in HBV-infected livers. These effects may contribute to an enhanced immune response and the clearance of HBV-associated antigens, including serum HBsAg, serum HBcAg, and HBcAg⁺ hepatocytes. Overall, this is the first indication that MAF can act as an adjuvant with GMI-HBVac to deplete Tregs in mice with an established CHB infection. This unique therapeutic vaccine regimen produced a functional cure, as revealed by the remarkable clearance of HBsAg.

Pegylated interferon-α-2b combined with tenofovir disoproxil fumarate, granulocyte-macrophage colony-stimulating factor, and hepatitis B vaccine treatment for naïve HBeAg-positive chronic hepatitis B patients: A prospective, multicenter, randomized controlled study

Hepatitis B surface antigen (HBsAg) loss or seroconversion is an ideal treatment endpoint for patients with chronic hepatitis B but is rarely achievable in  hepatitis B e-antigen (HBeAg)-positive patients using existing treatment strategies. In this study, the effect of pegylated interferon (peg-IFN) alfa-2b plus tenofovir disoproxil fumarate (TDF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and hepatitis B vaccine was evaluated. This randomized controlled trial was conducted at nine liver centers in Chinese university hospitals from May 2018 to July 2020. Patients (n = 303) enrolled were randomly administered peg-IFN-α-2b combined with TDF, GM-CSF, and hepatitis B vaccine (experimental group); peg-IFN-α-2b plus TDF (control group 2); or interferon-α-2b alone (control group 1). The primary efficacy endpoint was HBsAg seroconversion at 48 weeks and the secondary endpoint included safety. No differences in baseline HBsAg levels were observed among the groups. The primary endpoint was achieved in three (3.0%), one (1.03%), and one (1.19%) patient in the experimental group, control group 2, and control group 1, respectively. The incidence of HBsAg seroconversion at week 48 was not significantly different among the three groups (p = 0.629). However, the decrease in serum levels of HBsAg at week 48 was significantly higher in the experimental and control group 2 compared with that in control group 1 (p = 0.008 and 0.006, respectively). No significant difference between the experimental and control group 2 was observed (p = 0.619). Adverse events were not significantly different among the groups except for the lower incidence of neutropenia in the experimental group. Peg-IFN-α-2b combined with TDF, GM-CSF, and hepatitis B vaccine is not superior to peg-IFN-α-2b combined with TDF in HBeAg-positive naïve patients. Clinical Trials Registration: ChiCTR1800016173.

Development of a therapeutic vaccine targeting Merkel cell polyomavirus capsid protein VP1 against Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare but aggressive skin cancer with a high mortality rate, while Merkel cell polyomavirus (MCV) has been pointed as the causative agent of MCC. A better prognosis of MCC associated with a high level of antibodies against the capsid protein VP1 suggests that anti-VP1 immune response might be essential against MCC growth. In the current study, we developed a VP1-target vaccine formulated with CRA. Using a tumorigenic CMS5-VP1 tumor model, the vaccine-induced a potent antitumor efficacy in a dose-dependent manner was evidently demonstrated and mainly mediated by both VP1-specific CD4⁺and CD8⁺T-cell responses against the growth of CMS5-VP1 tumors in vaccinated BALB/c mice since the depletion of CD4⁺and CD8⁺T cells reverse the antitumor effects. Thus, immunotherapy with this vaccine represents a novel approach for the clinical treatment of aggressive MCV-related MCC in humans.

Effect of hepato-toxins in the acceleration of hepatic fibrosis in hepatitis B mice

Chronic liver diseases such as hepatitis B viral (HBV) infection and liver fibrosis have been a major health problem worldwide. However, less research has been conducted owing to the lack of animal models. The key purpose of this study was to determine the effects of different hepatotoxins in HBV-affected liver. In this study, we successfully generated a combined liver fibrosis model by administering HBV 1.2 plasmid and thioacetamide/ethanol (TAA/EtOH). To our knowledge, this is the first study in which an increase in the liver fibrosis level is observed by the intraperitoneal administration of TAA and EtOH in drinking water after the hydrodynamic transfection of the HBV 1.2 plasmid in C3H/HeN mice. The HBV+TAA/EtOH group exhibited higher level of hepatic fibrosis than that of the control groups. The hepatic stellate cell activation in the TAA- and EtOH-administered groups was demonstrated by the elevation in the level of fibrotic markers. In addition, high levels of collagen content and histopathological results were also used to confirm the prominent fibrotic levels. We established a novel HBV mice model by hydrodynamic injection-based HBV transfection in C3H/HeN mice. C3H/HeN mice were reported to have a higher HBV persistence level than that of the C57BL/6 mouse model. All the results showed an increased fibrosis level in the HBV mice treated with TAA and EtOH; hence, this model would be useful to understand the effect of hepatotoxins on the high risk of fibrosis after HBV infection. The acceleration of liver fibrosis can occur with prolonged administration as well as the high dosage of hepatotoxins in mice.