ABSTRACT
The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has had and still has a considerable impact on global public health. One of the characteristics of SARS-CoV-2 is a surface homotrimeric spike protein, the primary responsible for the host immune response upon infection. Here we show the preclinical studies of a broad protective SARS-CoV-2 subunit vaccine developed from our Trimer Domain platform using the Delta spike protein, from antigen design to purification, vaccine evaluation and manufacturability. The prefusion trimerized Delta spike protein, PF-D-Trimer, was highly expressed in Chinese hamster ovary (CHO) cells, purified by a rapid one-step anti-Trimer Domain monoclonal antibody immunoaffinity process and prepared as a vaccine formulation with an adjuvant. The immunogenicity studies demonstrated that this vaccine candidate induces robust immune responses in mouse, rat and Syrian hamster models. It also protects K18-hACE2 transgenic mice in a homologous virus challenge. The neutralizing antibodies induced by this vaccine display a cross-reactive capacity against the ancestral WA1 and Delta variants as well as different Omicron, including BA.5.2. The Trimer Domain platform was proven to be a key technology in the rapid production of the PF-D-Trimer vaccine and may be crucial to accelerate the development of updated versions of SARS-CoV-2 vaccines.
ABSTRACT
Infections with zoonotic viruses, such as flaviviruses, influenza virus, and the SARS-CoV-2 pandemic coronavirus constitute an increasing global risk. Hence, an urgent need exists for the development of broad-spectrum antivirals to prevent such outbreaks. Here, we show that the maduramycin and CP-80,219 aglycone polyether ionophores exhibit effective broad-spectrum antiviral activity, against various viruses, including Japanese encephalitis virus (JEV), Dengue virus (DENV), Zika virus (ZIKV), and Chikungunya virus (CHIKV), while also exhibiting promising activity against PR8 influenza virus and SARS-CoV-2. Moreover, liposome-encapsulated maduramycin and CP-80,219 provide full protection for mice from infection with JEV in vivo. Mechanistic studies suggest that aglycone polyether ionophores primarily inhibit the viral replication step without blocking endosome acidification to promote the fusion between viral and cellular membranes. The successful application of liposomes containing aglycone polyether ionophores in JEV-infected mice offers hope to the development of broad-spectrum antiviral drugs like penicillin back to 1940s.
ABSTRACT
Microbiota may coexist with the body and has a pivotal role in pathophysiological alterations such as intestinal immune defense, changes in brain function and regulation of hormone levels. There is increasing evidence indicating that intestinal microecological therapy is feasible and shows an ideal clinical outcome. Currently some progresses has been made in the study of clinical treatment and application of fecal microbiota transplantation. This article reviews the impact of fecal microbiota transplantation in digestive system disorders, neuropsychiatric disorders, endocrine system disorders, cardiovascular and cerebrovascular system disorders, blood system disorders and other typical bacterial intervention methods in recent years.
ABSTRACT
<p><b>OBJECTIVE</b>This study aimed at investigating whether notoginsenoside R1 (R1), a unique saponin found in Panax notoginseng could promote angiogenic activity on human umbilical vein endothelial cells (HUVECs) and elucidate their potential molecular mechanisms. In addition, vascular restorative activities of R1 was assessed in a chemically-induced blood vessel loss model in zebrafish.</p><p><b>METHODS</b>The in vitro angiogenic effect of R1 was compared with other previously reported angiogenic saponins Rg1 and Re. The HUVECs proliferation in the presence of R1 was determined by cell proliferation kit II (XTT) assay. R1, Rg1 and Re-induced HUVECs invasion across polycarbonate membrane was stained with Hoechst-33342 and quantified microscopically. Tube formation assay using matrigelcoated wells was performed to evaluate the pro-angiogenic actions of R1. In order to understand the mechanism underlying the pro-angiogenic effect, various pathway inhibitors such as SU5416, wortmannin (wort) or L-Nω-nitro- L-arginine methyl ester hydrochloride (L-NAME), SH-6 were used to probe the possible involvement of signaling pathway in the R1 mediated HUVECs proliferation. In in vivo assays, zebrafish embryos at 21 hpf were pre-treated with vascular endothelial growth factor (VEGF) receptor kinase inhibitor II (VRI) for 3 h only and subsequently post-treated with R1 for 48 h, respectively. The intersegmental vessels (ISVs) in zebrafish were assessed for the restorative effect of R1 on defective blood vessels.</p><p><b>RESULTS</b>R1 could stimulate the proliferation of HUVECs. In the chemoinvasion assay, R1 significantly increased the number of cross-membrane HUVECs. In addition, R1 markedly enhanced the tube formation ability of HUVECs. The proliferative effects of these saponins on HUVECs were effectively blocked by the addition of SU5416 (a VEGF-KDR/Flk-1 inhibitor). Similarly, pre-treatment with wort [a phosphatidylinositol 3-kinase (PI3K)-kinase inhibitor], L-NAME [an endothelial nitric oxide synthase (eNOS) inhibitor] or SH-6 (an Akt pathway inhibitor) significantly abrogated the R1 induced proliferation of HUVECs. In chemicallyinduced blood vessel loss model in zebrafish, R1 significantly rescue the damaged ISVs.</p><p><b>CONCLUSION</b>R1, similar to Rg1 and Re, had been showed pro-angiogenic action, possibly via the activation of the VEGF-KDR/Flk-1 and PI3K-Akt-eNOS signaling pathways. Our findings also shed light on intriguing pro-angiogenic effect of R1 under deficient angiogenesis condition in a pharmacologic-induced blood vessels loss model in zebrafish. The present study in vivo and in vitro provided scientific evidence to explain the ethnomedical use of Panax notoginseng in the treatment of cardiovascular diseases, traumatic injuries and wound healing.</p>
