A Novel Targeted RIG-I Receptor 5'Triphosphate Double Strain RNA-Based Adjuvant Significantly Improves the Immunogenicity of the SARS-CoV-2 Delta-Omicron Chimeric RBD-Dimer Recombinant Protein Vaccine.

The rapid mutation and spread of SARS-CoV-2 variants recently, especially through the emerging variants Omicron BA5, BF7, XBB and BQ1, necessitate the development of universal vaccines to provide broad spectrum protection against variants. For the SARS-CoV-2 universal recombinant protein vaccines, an effective approach is necessary to design broad-spectrum antigens and combine them with novel adjuvants that can induce high immunogenicity. In this study, we designed a novel targeted retinoic acid-inducible gene-I (RIG-I) receptor 5'triphosphate double strain RNA (5'PPP dsRNA)-based vaccine adjuvant (named AT149) and combined it with the SARS-CoV-2 Delta and Omicron chimeric RBD-dimer recombinant protein (D-O RBD) to immunize mice. The results showed that AT149 activated the P65 NF-κB signaling pathway, which subsequently activated the interferon signal pathway by targeting the RIG-I receptor. The D-O RBD + AT149 and D-O RBD + aluminum hydroxide adjuvant (Al) + AT149 groups showed elevated levels of neutralizing antibodies against the authentic Delta variant, and Omicron subvariants, BA1, BA5, and BF7, pseudovirus BQ1.1, and XBB compared with D-O RBD + Al and D-O RBD + Al + CpG7909/Poly (I:C) groups at 14 d after the second immunization, respectively. In addition, D-O RBD + AT149 and D-O RBD + Al + AT149 groups presented higher levels of the T-cell-secreted IFN-γ immune response. Overall, we designed a novel targeted RIG-I receptor 5'PPP dsRNA-based vaccine adjuvant to significantly improve the immunogenicity and broad spectrum of the SARS-CoV-2 recombinant protein vaccine.

A Novel Single-Stranded RNA-Based Adjuvant Improves the Immunogenicity of the SARS-CoV-2 Recombinant Protein Vaccine.

The research and development (R&D) of novel adjuvants is an effective measure for improving the immunogenicity of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recombinant protein vaccine. Toward this end, we designed a novel single-stranded RNA-based adjuvant, L2, from the SARS-CoV-2 prototype genome. L2 could initiate retinoic acid-inducible gene-I signaling pathways to effectively activate the innate immunity. ZF2001, an aluminum hydroxide (Al) adjuvanted SARS-CoV-2 recombinant receptor binding domain (RBD) subunit vaccine with emergency use authorization in China, was used for comparison. L2, with adjuvant compatibility with RBD, elevated the antibody response to a level more than that achieved with Al, CpG 7909, or poly(I:C) as adjuvants in mice. L2 plus Al with composite adjuvant compatibility with RBD markedly improved the immunogenicity of ZF2001; in particular, neutralizing antibody titers increased by about 44-fold for Omicron, and the combination also induced higher levels of antibodies than CpG 7909/poly(I:C) plus Al in mice. Moreover, L2 and L2 plus Al effectively improved the Th1 immune response, rather than the Th2 immune response. Taken together, L2, used as an adjuvant, enhanced the immune response of the SARS-CoV-2 recombinant RBD protein vaccine in mice. These findings should provide a basis for the R&D of novel RNA-based adjuvants.

Ginkgo biloba Extract Reduces Hippocampus Inflammatory Responses, Improves Cardiac Functions And Depressive Behaviors In A Heart Failure Mouse Model.

BACKGROUND: Depression has been shown to share an extremely high comorbidity with heart failure (HF). Ginkgo biloba extract (GBE) is a widely used traditional Chinese medicine in cardiac disease. However, its potential therapeutic effect on depressive symptoms following HF largely remains unknown. In this article, we aimed to investigate its effects in reducing depressive behaviors of a HF mouse model. Moreover, we also discussed whether its effects are associated with changes in neural inflammation and 5-hydroxytryptamine (5-HT) signaling. METHODS: Mice were randomly divided into three groups: sham, HF+saline and HF+GBE (150 mg/kg/d) (n=10 per group). Systolic heart failure was induced by ligating the left anterior descending coronary artery. Cardiac functions together with depressive-like behaviors were measured after 4 weeks' treatment. Levels of brain natriuretic peptide (BNP), 5-HT, 5-HT receptor 2A (5-HT2AR), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), vascular endothelial growth factor (VEGF), hypoxia inducible factor-1 (HIF-1), (cleaved) caspase-3, Bax and Bcl-2 were analyzed by Western blot, Elisa and immunohistochemistry at the end of the experiments. RESULTS: GBE benefited antidepressant-like behaviors and improved cardiac functions in mice with heart failure. Levels of TNF-α, IL-1ß and 5-HT were reduced in the hippocampus after the administration of GBE. Further experiments revealed that GBE also blocked the release of serotonin in the peripheral blood and triggered HIF-1 induced anti-apoptotic pathways. CONCLUSION: GBE has potential therapeutic effects in relieving depressive status of patients with HF.

Antidepressant-like effects of ginseng fruit saponin in myocardial infarction mice.

BACKGROUND: Recently, the development of cardiovascular disease (CVD) has been proved to be closely associated with depression in which 5-HT plays a crucial role. Ginseng Fruit Saponin (GFS) and Metoprolol are two drugs which have beneficial effects on the cardiovascular system in Myocardial Infarction (MI) mice. However, their effects on depression-like behaviors after MI and its underlying mechanisms remain unknown. We aimed to investigate their antidepressive-like effects as well as their impacts on the 5-HT system. METHODS: The MI model was established by ligating left anterior descending coronary artery. Mice were administered with GFS, Metoprolol or saline for 4 weeks. Cardiac function was evaluated and depressive-like behaviors were quantified at the end of the experiments. Masson's staining was used to assess myocardial fibrosis while immunohistochemistry, western blot, ELISA and qPCR were performed to analyze the levels of 5-HT and its related genes. RESULTS: Compared with MI groups, Both GFS and Metoprolol treatments significantly improved cardiac function and reduced myocardial fibrosis. Moreover, GFS but not Metoprolol increased the levels of 5-HT in the cortex and rescued depression-like behaviors in MI mice. CONCLUSIONS: GFS has potential antidepressive effects and the mechanisms involve the regulation of 5-HT concentrations in the cortex.