3,872 research outputs found

    T cell immunity rather than antibody mediates cross-protection against Zika virus infection conferred by a live attenuated Japanese encephalitis SA14-14-2 vaccine.

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    Zika virus (ZIKV) and Japanese encephalitis virus (JEV) are closely related to mosquito-borne flaviviruses. Japanese encephalitis (JE) vaccine SA14-14-2 has been in the Chinese national Expanded Program on Immunization since 2007. The recent recognition of severe disease syndromes associated with ZIKV, and the identification of ZIKV from mosquitoes in China, prompts an urgent need to investigate the potential interaction between the two. In this study, we showed that SA14-14-2 is protective against ZIKV infection in mice. JE vaccine SA14-14-2 triggered both Th1 and Th2 cross-reactive immune responses to ZIKV; however, it was cellular immunity that predominantly mediated cross-protection against ZIKV infection. Passive transfer of immune sera did not result in significant cross-protection but did mediate antibody-dependent enhancement in vitro, though this did not have an adverse impact on survival. This study suggests that the SA14-14-2 vaccine can protect against ZIKV through a cross-reactive T cell response. This is vital information in terms of ZIKV prevention or precaution in those ZIKV-affected regions where JEV circulates or SA14-14-2 is in widespread use, and opens a promising avenue to develop a novel bivalent vaccine against both ZIKV and JEV. KEY POINTS: • JEV SA14-14-2 vaccine conferred cross-protection against ZIKV challenge in mice. • T cell immunity rather than antibody mediated the cross-protection. • It provides important information in terms of ZIKV prevention or precaution

    Cross-Protection Against Four Serotypes of Dengue Virus in Mice Conferred by a Zika DNA Vaccine

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    Both Zika virus (ZIKV) and four serotypes of dengue virus (DENV1–4) are antigenically related mosquito-borne flaviviruses that co-circulate in overlapping geographic distributions. The considerable amino acid sequence homology and structural similarities between ZIKV and DENV1–4 may be responsible for the complicated immunological cross-reactivity observed for these viruses. Thus, a successful Zika vaccine needs to not only confer protection from ZIKV infection but must also be safe during secondary exposures with other flavivirus, especially DENVs. In this study, we used a Zika DNA vaccine candidate (pV-ZME) expressing the ZIKV premembrane and envelop proteins to immunize BALB/c mice and evaluated the potential cross-reactive immune responses to DENV1–4. We observed that three doses of the pV-ZME vaccine elicited the production of cross-reactive antibodies, cytokines and CD8+ T cell responses and generated cross-protection against DENV1–4. Our results demonstrate a novel approach for design and development of safe Zika and/or dengue vaccines

    Synthesis of Hollow ZnSnO 3

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    Hollow ZnSnO3 nanospheres were synthesized by a hydrothermal method using ZnO nanospheres as the hard template and raw material simultaneously. The combined characterizations of X-ray diffraction (XRD), scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HRTEM) confirmed the successful preparation of hollow ZnSnO3 nanospheres. The gas-sensing results indicated that the sensor made from hollow ZnSnO3 nanospheres exhibited high sensitivity, good selectivity, and stability to ethanol at a low operating temperature of 200°C. The sensitivity was about 32 and the response and recovery time were about 4 s and 30 s for 100 ppm ethanol, respectively. The enhancement in gas-sensing properties was attributed to the hollow nanostructures and high specific surface areas of ZnSnO3

    Vaccination With a Single Consensus Envelope Protein Ectodomain Sequence Administered in a Heterologous Regimen Induces Tetravalent Immune Responses and Protection Against Dengue Viruses in Mice

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    The development of a safe and effective tetravalent dengue vaccine that elicits protection against all dengue virus (DENV) serotypes is urgently needed. The consensus sequence of the ectodomain of envelope (E) protein of DENV (cE80) has been examined as an immunogen previously. In the current study, a cE80 DNA (D) vaccine was constructed and evaluated in conjunction with the cE80 protein (P) vaccine to examine whether both vaccines used together can further improve the immune responses. The cE80 DNA vaccine was administrated using either a homologous (DNA alone, DDD) or heterologous (DNA prime-protein boost: DDP or DPP) regimen, and evaluated for immunogenicity and protective efficacy in mice. Among the three DNA-based immunization regimens tested, DDP immunization is the optimal immunization regimen that elicited the greatest systemic immune response and conferred protection against all four DENV serotypes. This work provides innovative ideas for the development of consensus E-based dengue vaccines and the testing of optimal immunization regimens

    Apolipoprotein A1 suppresses the hypoxia-induced angiogenesis of human retinal endothelial cells by targeting PlGF

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    AIM: To investigate the anti-angiogenic effect of apolipoprotein A1 (apoA1) on primary human retinal vascular endothelial cells (HRECs) and explore the possible mechanism. METHODS: The primary HRECs were transfected with apoA1-GFP recombinant lentiviral and were compared with cells undergoing transfection with empty lentiviral vectors. Hypoxia chambers were used to simulate the anoxic environment of cells under pathological condition. The concentrations of secreted vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) were measured by enzyme-linked immunosorbent assay (ELISA). Cell migration ability was detected by wound healing assay. The sprouting of HRECs was determined by tube formation assay. The protein levels of extracellular signal regulated kinase 1/2 (ERK1/2) and phosphorylated ERK1/2 (p-ERK1/2) were measured by Western blot. RESULTS: Overexpressed apoA1 in hypoxia-induced HRECs significantly suppressed PlGF (0.67±0.10 folds, P=0.007). Overexpressed apoA1 also attenuated hypoxia-induced cell migration (0.32±0.11 folds, P<0.0001), tube formation (0.66±0.01 folds, P<0.0001) and the phosphorylation levels of ERK (0.6±0.11 folds, P=0.025). Pretreatment of mitogen-activated protein kinase kinase (MEK) inhibitor (U0126) further reduced the PlGF and angiogenesis in hypoxia-induced HRECs. CONCLUSION: ApoA1 inhibits the angiogenesis at least in part by inactivating ERK1/2 in hypoxia-induced HRECs. Moreover, apoA1 suppresses the PlGF expression, which selectively associated with pathological angiogenesis

    Lactylation, a Novel Metabolic Reprogramming Code: Current Status and Prospects

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    Lactate is an end product of glycolysis. As a critical energy source for mitochondrial respiration, lactate also acts as a precursor of gluconeogenesis and a signaling molecule. We briefly summarize emerging concepts regarding lactate metabolism, such as the lactate shuttle, lactate homeostasis, and lactate-microenvironment interaction. Accumulating evidence indicates that lactate-mediated reprogramming of immune cells and enhancement of cellular plasticity contribute to establishing disease-specific immunity status. However, the mechanisms by which changes in lactate states influence the establishment of diverse functional adaptive states are largely uncharacterized. Posttranslational histone modifications create a code that functions as a key sensor of metabolism and are responsible for transducing metabolic changes into stable gene expression patterns. In this review, we describe the recent advances in a novel lactate-induced histone modification, histone lysine lactylation. These observations support the idea that epigenetic reprogramming-linked lactate input is related to disease state outputs, such as cancer progression and drug resistance
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