Improvement of B Cell Responses by an HIV-1 Amphiphilic Polymer Nanovaccine.

The human immunodeficiency virus (HIV) has infected over 84 million people since its discovery and is a huge threat to human health. While an HIV vaccine is urgently needed to curb this devastating pandemic, it has been notoriously difficult to develop, partly due to the extraordinary high level of genetic variation of HIV. We designed a new HIV-1 envelope glycoprotein nanoparticle (Env/NP) vaccine using amphiphilic polymers. The Env/NP vaccine induced more potent and broader neutralizing activities against multiple HIV-1 subtypes. Moreover, it elicits similar neutralizing antibody responses after the storage at -80 °C, 4 °C or room temperature post lyophilization. These results demonstrate that the new Env/NP vaccine not only improves the HIV vaccine immune responses but also is stable under different storage conditions. This new nanovaccine approach can readily apply to other protein-based vaccines.

Enhancement of Neutralization Responses through Sequential Immunization of Stable Env Trimers Based on Consensus Sequences from Select Time Points by Mimicking Natural Infection.

HIV-1 vaccines have been challenging to develop, partly due to the high level of genetic variation in its genome. Thus, a vaccine that can induce cross-reactive neutralization activities will be needed. Studies on the co-evolution of antibodies and viruses indicate that mimicking the natural infection is likely to induce broadly neutralizing antibodies (bnAbs). We generated the consensus Env sequence for each time point in subject CH505, who developed broad neutralization activities, and selected five critical time points before broad neutralization was detected. These consensus sequences were designed to express stable Env trimers. Priming with the transmitted/founder Env timer and sequential boosting with these consensus Env trimers from different time points induced broader and more potent neutralizing activities than the BG505 Env trimer in guinea pigs. Analysis of the neutralization profiles showed that sequential immunization of Env trimers favored nAbs with gp120/gp41 interface specificity while the BG505 Env trimer favored nAbs with V2 specificity. The unique features such as consensus sequences, stable Env trimers and the sequential immunization to mimic natural infection likely has allowed the induction of improved neutralization responses.

Balanced detection spectral-domain optical coherence tomography with a single line-scan camera.

This paper describes a balanced detection spectral-domain optical coherence tomography (BD-SD-OCT) system for suppressing autocorrelation (AC) artifacts and increasing the signal-to-noise ratio (SNR). The system employed three optical fiber couplers to generate two phase-opposed interference spectra that were acquired by a single line-scan camera simultaneously. When compared with conventional unbalanced detection SD-OCT systems, the developed BD-SD-OCT system improved the SNR by 5.4-6 dB and suppressed the AC term by 5-10 dB. The imaging quality of the BD-SD-OCT system was evaluated by in vivo imaging of human nail folds and retinas.

Hollow Pd/MOF Nanosphere with Double Shells as Multifunctional Catalyst for Hydrogenation Reaction.

A new type of hollow nanostructure featured double metal-organic frameworks shells with metal nanoparticles (MNPs) is designed and fabricated by the methods of ship in a bottle and bottle around the ship. The nanostructure material, hereinafter denoted as Void@HKUST-1/Pd@ZIF-8, is confirmed by the analyses of photograph, transmission electron microscopy, scanning electron microscopy, powder X-ray diffraction, inductively coupled plasma, and N2 sorption. It possesses various multifunctionally structural characteristics such as hollow cavity which can improve mass transfer, the adjacent of the inner HKUST-1 shell to the void which enables the matrix of the shell to host and well disperse MNPs, and an outer ZIF-8 shell which acts as protective layer against the leaching of MNPs and a sieve to guarantee molecular-size selectivity. This makes the material eligible candidates for the heterogeneous catalyst. As a proof of concept, the liquid-phase hydrogenation of olefins with different molecular sizes as a model reaction is employed. It demonstrates the efficient catalytic activity and size-selectivity of Void@HKUST-1/Pd@ZIF-8.

Graphene oxide based surface-enhanced Raman scattering probes for cancer cell imaging.

The intrinsic Raman signals provide the potential of graphene oxide (GO) for cellular imaging. Herein, novel surface-enhanced Raman scattering (SERS) labels based on GO-Ag nanoparticle (NP) composites are developed for fast cellular probing and imaging. The optimum SERS signals of the hybrids can be well controlled by adjusting the weight ratio between AgNO(3) and GO. Utilizing GO-AgNPs as the highly sensitive optical probes, fast SERS imaging of cancer cells is realized with a very short integration time of about 0.06 s per pixel. Furthermore, folic acid (FA) is covalently conjugated to GO for targeting specific cancer cells with folate receptors (FRs). Targeted SERS images can be acquired after 2 h incubation with FA-GO-AgNPs, which are specifically located on the surface of FR-positive cancer cells. In conclusion, the GO-based Raman probes mentioned here open up exciting opportunities for biomedical imaging.

[Green synthesis of silver nanoparticles and their application in SERS].

In the present paper, we have successfully synthesized silver nancomparticles by reducing of silver nitrate in alkaline solution via 60 degrees C water bath for 20 minutes with the use of tyrosine, a nontoxic and green macromolecule, as a reducing and stabilizing agent. The formation of silver nanoparticles was observed visually by color change of the solutions (from faint yellow to brown yellow). The morphologies of the Ag NPs were characterized by UV-Vis absorption spectroscopy and transmission electron microscopy (TEM). The UV-Vis absorption peak of silver nanoparticles located at 412 nm. The TEM image of silver nanoparticles indicated that the diameters of nanospheres are mainly in the range 15-25 nm. In order to evaluate the SERS activity of the silver nancomparticles, crystal violet and folic acid were used as the Raman probe molecule. The experimental results indicated that there are two ascendancies, firstly, the approach is convenient and the reaction condition is facile, secondly, tyrosine is a water-soluble, nontoxic and biodegradable macromolecule, which makes this approach provide a green strategy to prepare Ag NPs. Significantly, the synthesized Ag NPs exhibits good surface enhanced Raman scattering (SERS) activity as SERS substrates to detect crystal violet and folic acid in aqueous solution.

Integrative metabolomic and transcriptomic reveals potential mechanism for promotion of ginsenoside synthesis in Panax ginseng leaves under different light intensities.

Panax ginseng C.A. Meyer is a shade plant, and its leaves are an important medicinal part of P. ginseng. Light intensity plays a crucial role in physiological activities and metabolite accumulation in P. ginseng. Currently, little is known about the molecular mechanisms underlying physiological changes and quality under different light intensities in P. ginseng leaves. Therefore, we investigated the changes in photosynthetic physiology, secondary metabolism, transcriptomics, and metabolomics of P. ginseng leaves under different light intensities [T20 (20 µmol m-2·s-1), T50 (50 µmol m-2·s-1), T100 (100 µmol m-2·s-1)]]. Higher light intensity positively influenced the yield, photosynthesis, and accumulation of polysaccharides, soluble sugars, terpenoids, and ginsenosides in P. ginseng leaves. The T100 treatment notably promoted the accumulation of ginsenosides in the leaves, resulting in a 68.32% and 45.55% increase in total ginsenosides compared to the T20 and T50 treatments, respectively. Ginsenosides Rg1, Re, Rb1, Rc, Rg2, Rb2, Rb3, and Rd were 1.28-, 1.47-, 2.32-, 1.64-, 1.28-, 2.59-, 1.66-, and 2.28-times higher than in the T20 treatment. Furthermore, 285 differentially accumulated metabolites (DAMs) and 4218 differentially expressed genes (DEGs) in the metabolome and transcriptome of P. ginseng leaves, respectively, were identified. 13 triterpenoid saponins were significantly upregulated, and three were downregulated. The expression of genes encoding photosystem II reaction center proteins was upregulated under the T100 treatment, thereby increasing photosynthetic activity. The T100 treatment enhanced the expression of genes involved in photosynthetic carbon and energy metabolism in P. ginseng. The expression of antenna protein synthesis genes was upregulated under the T20, which increased the ability to capture light in P. ginseng leaves. T100 upregulated the expression of HMGR, SS, CYP716A53v2, UGT74AE, PgUGT1, and UGTPg45, thereby promoting terpene and ginsenoside synthesis. In summary, 100 µmol m-2·s-1 was conducive to quality formation of P. ginseng leaves. This study elucidates molecular mechanisms underlying the photosynthetic physiology and ginsenoside synthesis in P. ginseng under varying light intensities and provides a theoretical basis for the P. ginseng cultivation and its industrial production of secondary metabolites.

An Adenovirus-Based Recombinant Herpes Simplex Virus 2 (HSV-2) Therapeutic Vaccine Is Highly Protective against Acute and Recurrent HSV-2 Disease in a Guinea Pig Model.

Genital herpes (GH) has become one of the most common sexually transmitted diseases worldwide, and it is spreading rapidly in developing countries. Approximately 90% of GH cases are caused by HSV-2. Therapeutic HSV-2 vaccines are intended for people already infected with HSV-2 with the goal of reducing clinical recurrences and recurrent virus shedding. In our previous work, we evaluated recombinant adenovirus-based vaccines, including rAd-gD2ΔUL25, rAd-ΔUL25, and rAd-gD2, for their potency as prophylactic vaccines. In this study, we evaluated these three vaccines as therapeutic vaccines against acute and recurrent diseases in intravaginal challenged guinea pigs. Compared with the control groups, the recombinant vaccine rAd-gD2ΔUL25 induced a higher titer of the binding antibody, and rAd-gD2 + rAd-ΔUL25 induced a higher titer of the neutralizing antibody. Both rAd-gD2ΔUL25 and rAd-gD2 + rAd-ΔUL25 vaccines significantly enhanced the survival rate by 50% compared to rAd-gD2 and reduced viral replication in the genital tract and recurrent genital skin disease. Our findings provide a new perspective for HSV-2 therapeutic vaccine research and provide a new technique to curtail the increasing spread of HSV-2.

Comparison of effects of multiple adjuvants and immunization routes on the immunogenicity and protection of HSV-2 gD subunit vaccine.

Genital herpes caused by herpes simplex virus type 2 (HSV-2) poses a global health issue. HSV-2 infection increases the risk of acquiring HIV infection. Studies have demonstrated that HSV-2 subunit vaccines have potential benefits, but require adjuvants to induce a balanced Th1/Th2 response. To develop a novel, effective vaccine, in this study, a truncated glycoprotein D (aa 1-285) of HSV-2 was formulated with an Al(OH)3 adjuvant, three squalene adjuvants, zMF59, zAS03, and zAS02, or a mucosal adjuvant, bacterium-like particles (BLPs). The immunogenicity of these subunit vaccines was evaluated in mice. After three immunizations, vaccines formulated with Al(OH)3, zMF59, zAS03, and zAS02 (intramuscularly) induced higher titers of neutralizing antibody than that formulated without adjuvant, and in particular, mice immunized with the vaccine plus zAS02 had the highest neutralizing antibody titers and tended to produce a more balanced immune reaction than others. Intranasal gD2-PA-BLPs also induced excellent IgA levels and a more balanced Th1 and Th2 responses than intranasal gD2. After challenge with a lethal dose of HSV-2, all five adjuvants exhibited a positive effect in improving the survival rate. zAS02 and gD2-PA-BLPs enhanced survival by 50% and 25%, respectively, when compared with the vaccine without adjuvant. zAS02 was the only adjuvant that resulted in complete vaginal virus clearance and genital lesion healing within eight days. These results demonstrate the potential of using zAS02 as a subunit vaccine adjuvant, and BLPs as a mucosal vaccine adjuvant.

Interferon Inhibition Enhances the Pilot-Scale Production of Rabies Virus in Human Diploid MRC-5 Cells.

Inactivated vaccines based on cell culture are very useful in the prevention and control of many diseases. The most popular strategy for the production of inactivated vaccines is based on monkey-derived Vero cells, which results in high productivity of the virus but has a certain carcinogenic risk due to non-human DNA contamination. Since human diploid cells, such as MRC-5 cells, can produce a safer vaccine, efforts to develop a strategy for inactivated vaccine production using these cells have been investigated using MRC-5 cells. However, most viruses do not replicate efficiently in MRC-5 cells. In this study, we found that rabies virus (RABV) infection activated a robust interferon (IFN)-ß response in MRC-5 cells but almost none in Vero cells, suggesting that the IFN response could be a key limiting factor for virus production. Treatment of the MRC-5 cells with IFN inhibitors increased RABV titers by 10-fold. Additionally, the RABV titer yield was improved five-fold when using IFN receptor 1 (IFNAR1) antibodies. As such, we established a stable IFNAR1-deficient MRC-5 cell line (MRC-5IFNAR1-), which increased RABV production by 6.5-fold compared to normal MRC-5 cells. Furthermore, in a pilot-scale production in 1500 square centimeter spinner flasks, utilization of the MRC-5IFNAR1- cell line or the addition of IFN inhibitors to MRC cells increased RABV production by 10-fold or four-fold, respectively. Thus, we successfully established a human diploid cell-based pilot scale virus production platform via inhibition of IFN response for rabies vaccines, which could also be used for other inactivated virus vaccine production.

Fabrication of Magnetic Pd/MOF Hollow Nanospheres with Double-Shell Structure: Toward Highly Efficient and Recyclable Nanocatalysts for Hydrogenation Reaction.

MNPs@MOF catalysts obtained by encapsulating metal nanoparticles (NPs) into metal-organic frameworks (MOFs) show fascinating performance in heterogeneous catalysis. The improvement of catalytic activity and reusability of MNPs@MOF catalysts has been a great challenge for a long time. Herein, we demonstrate well-designed Pd/MOFs, featuring hollow double-shell structure and magnetic property, exhibiting high reusability, efficient catalytic activity, and size selectivity for hydrogenation reaction. The as-synthesized Pd/MOF, denoted as Void nFe3O4@Pd/ZIF-8@ZIF-8, possesses diverse functional structural features. The hollow cavity can improve mass transfer; superparamagnetic Fe3O4 NPs embedded in the inner MOF shell can enhance the separation and recyclability; Pd NPs are highly dispersed in the matrix of the inner MOF shell, and the outer MOF shell acts as a protector to prevent the leaching of Pd NPs and a sieve to achieve size selectivity. As a proof of concept, the Void nFe3O4@Pd/ZIF-8@ZIF-8 catalyst exhibited excellent performance for the hydrogenation of styrene at room temperature. The activity only reduced 10% after 20 cycles for the higher conversions (>90%), and the lower conversion only decreased 3.6% (from 32.5 to 28.9% conversion) after twenty consecutive cycles, indicating the good and intrinsic reusability of the catalyst. The proposed structure in this work provides a strategy to effectively improve the reusability of MNPs@MOF catalysts, which would increase their practical applications.

Performance of Homologous and Heterologous Prime-Boost Immunization Regimens of Recombinant Adenovirus and Modified Vaccinia Virus Ankara Expressing an Ag85B-TB10.4 Fusion Protein against Mycobacterium tuberculosis.

Tuberculosis (TB) remains a serious health issue around the word. Adenovirus (Ad)-based vaccine and modified vaccinia virus Ankara (MVA)-based vaccine have emerged as two of the most promising immunization candidates over the past few years. However, the performance of the homologous and heterologous prime-boost immunization regimens of these two viral vector-based vaccines remains unclear. In the present study, we constructed recombinant Ad and MVA expressing an Ag85B-TB10.4 fusion protein (AdH4 and MVAH4) and evaluated the impact of their different immunization regimens on the humoral and cellular immune responses. We found that the viral vector-based vaccines could generate significantly higher levels of antigen-specific antibodies, IFN-γ-producing splenocytes, CD69⁺CD8⁺ T cells, and IFN-γ secretion when compared with bacillus Calmette-Guérin (BCG) in a mouse model. AdH4-containing immunization regimens (AdH4-AdH4, AdH4-MVAH4, and MVAH4-AdH4) induced significantly stronger antibody responses, much more IFN-γ-producing splenocytes and CD69⁺CD8⁺ T cells, and higher levels of IFN-γ secretion when compared with the MVAH4-MVAH4 immunization regimen. The number of IFN-γ-producing splenocytes sensitive to CD8⁺ T-cell restricted peptides of Ag85B (9-1p and 9-2p) and Th1-related cytokines (IFN-γ and TNF-α) in the AdH4-MVAH4 heterologous prime-boost regimen immunization group was significantly higher than that in the other viral vector-based vaccine- and BCG-immunized groups, respectively. These results indicate that an immunization regimen involving AdH4 may have a higher capacity to induce humoral and cellular immune responses against TB in mice than that by regimens containing BCG or MVAH4 alone, and the AdH4-MVAH4 prime-boost regimen may generate an ideal protective effect.

Silver nanoaggregates on chitosan functionalized graphene oxide for high-performance surface-enhanced Raman scattering.

Herein we describe a self-assembly synthesis of graphene oxide/Ag nanoparticles nano-composites (GO/CS/AgNPs) by non-covalent attachment of AgNPs to chitosan (CS) functionalized graphene oxide (GO) sheets. The negatively charged AgNPs are prone to form aggregates on GO/CS via electrostatic interaction, which is extremely beneficial to the surface-enhanced Raman scattering (SERS) detection of aromatic molecules. Taking advantage of the enrichment of target molecules on GO, the obtained hybrids exhibit strong SERS activity to aromatic molecules (trypan blue and methylene blue). Furthermore, SERS signals of a negatively charged molecule (trypan blue) are stronger than signals of a positively charged molecule (methylene blue) due to the different adsorption capacity of GO/CS/AgNPs for the two opposite charged molecules through electrostatic interaction. Moreover, GO/CS/AgNPs remarkably enhance the main peaks of l-phenylalanine, in comparison with the silver nanoparticles, showing great potential for biomedical applications.

Study of support vector machine and serum surface-enhanced Raman spectroscopy for noninvasive esophageal cancer detection.

The ability of combining serum surface-enhanced Raman spectroscopy (SERS) with support vector machine (SVM) for improving classification esophageal cancer patients from normal volunteers is investigated. Two groups of serum SERS spectra based on silver nanoparticles (AgNPs) are obtained: one group from patients with pathologically confirmed esophageal cancer (n=30) and the other group from healthy volunteers (n=31). Principal components analysis (PCA), conventional SVM (C-SVM) and conventional SVM combination with PCA (PCA-SVM) methods are implemented to classify the same spectral dataset. Results show that a diagnostic accuracy of 77.0% is acquired for PCA technique, while diagnostic accuracies of 83.6% and 85.2% are obtained for C-SVM and PCA-SVM methods based on radial basis functions (RBF) models. The results prove that RBF SVM models are superior to PCA algorithm in classification serum SERS spectra. The study demonstrates that serum SERS in combination with SVM technique has great potential to provide an effective and accurate diagnostic schema for noninvasive detection of esophageal cancer.