Immunoglobin G Sero-Dynamics Aided Host Specific Linear Epitope Identification and Differentiation of Infected from Vaccinated Hosts.

Differentiation of infected from vaccinated hosts (DIVH) is a critical step in virus eradication programs. DIVH-compatible vaccines, however, take years to develop, and are therefore unavailable for fighting the sudden outbreaks that typically drive pandemics. Here, we establish a protocol for the swift and efficient development of DIVH assays, and show that this approach is compatible with any type of vaccines. Using porcine circovirus 2 (PCV2) as the experimental model, the first step is to use Immunoglobin G (IgG) sero-dynamics (IsD) curves to aid epitope discovery (IsDAED): PCV2 Cap peptides were categorized into three types: null interaction, nonspecific interaction (NSI), and specific interaction (SI). We subsequently compared IsDAED approach and traditional approach, and demonstrated identifying SI peptides and excluding NSI peptides supports efficient diagnostic kit development, specifically using a protein-peptide hybrid microarray (PPHM). IsDAED directed the design of a DIVH protocol for three types of PCV2 vaccines (while using a single PPHM). Finally, the DIVH protocol successfully differentiated infected pigs from vaccinated pigs at five farms. This IsDAED approach is almost certainly extendable to other viruses and host species. IMPORTANCE Sudden outbreaks of pandemics caused by virus, such as SARS-CoV-2, has been determined as a public health emergency of international concern. However, the development of a DIVH-compatible vaccine is time-consuming and full of uncertainty, which is unsuitable for an emergent situation like the ongoing COVID-19 pandemic. Along with the development and public health implementation of new vaccines to prevent human diseases, e.g., human papillomavirus vaccines for cervical cancer; enterovirus 71 vaccines for hand, foot, and mouth disease; and most recently SARS-CoV-2, there is an increasing demand for DIVH. Here, we use the IsDAED approach to confirm SI peptides and to exclude NSI peptides, finally to direct the design of a DIVH protocol. It is plausible that our IsDAED approach is applicable for other infectious disease.

Enhancing the Sensitivity of Surface Plasmon Resonance Measurements Utilizing Polymer Film/Au Assemblies.

Surface plasmon resonance (SPR) is used to infer information about a sample that is in contact with an Au-coated glass slide coupled to the SPR prism. Shifts in the angle of the "SPR minimum reflection" can be related to changes in the refractive index (and/or thickness) of the sample that is in contact with the Au film, which can then be used to determine the concentration of an analyte in that sample. Here, we show that by depositing a layer of poly(N-isopropylacrylamide-co-acrylic acid) [p(NIPAm-co-AAc)] microgel on the SPR's Au film, with a subsequent layer of Au deposited on top of the microgels, the sensitivity of SPR to changes in solution properties can be enhanced. We investigated the sensitivity of the SPR to changes in the temperature of water in contact with the SPR's Au film as a function of the microgel immobilization density and the thickness of the Au layer deposited on the microgel layer. The data revealed that the SPR's Au film densely coated with microgels, with 5 nm of Au deposited, exhibited the maximal enhancement. The plasmon coupling effect between the additional Au film on the microgels and the SPR's Au film was further confirmed by 3D finite difference time domain simulations.

Epitope-Containing Short Peptides Capture Distinct IgG Serodynamics That Enable Differentiating Infected from Vaccinated Animals for Live-Attenuated Vaccines.

Differentiating infected from vaccinated animals (DIVA) strategies have been central enabling techniques in several successful viral disease elimination programs. However, owing to their long and uncertain development process, no DIVA-compatible vaccines are available for many important diseases. We report herein a new DIVA strategy based on hybrid protein-peptide microarrays which can theoretically work with any vaccine. Leading from our findings from peste des petits ruminants (PPR) virus, we found 4 epitope-containing short peptides (ECSPs) which have distinct IgG serodynamics: anti-ECSP IgGs only exist for 10 to 60 days postvaccination (dpv), while anti-protein IgGs remained at high levels for >1,000 dpv. These data enabled the design of a DIVA diagnostic microarray containing 4 ECSPs and 3 proteins, which, unlike competitive enzyme-linked immunosorbent assay (cELISA) and virus neutralization tests (VNTs), enables ongoing monitoring of serological differences between vaccinated individuals and individuals exposed to the pathogen. For 25 goats after 60 dpv, 13 were detected with positive anti-ECSP IgGs, indicating recent infections in vaccinated goat herds. These DIVA diagnostic microarrays will almost certainly facilitate eradication programs for (re)emerging pathogens and zoonoses.IMPORTANCE Outbreaks of infectious diseases caused by viruses, such as pseudorabies (PR), foot-and-mouth disease (FMD), and PPR viruses, led to economic losses reaching billions of dollars. Both PR and FMD were eliminated in several countries via large-scale vaccination programs using DIVA-compatible vaccines, which lack the gE protein and nonstructural proteins, respectively. However, there are still extensive challenges facing the development and deployment of DIVA-compatible vaccines because they are time-consuming and full of uncertainty. Further, the negative marker strategy used for DIVA-compatible vaccines is no longer functional for live-attenuated vaccines. To avoid these disadvantageous scenarios, a new strategy is desired. Here, we made the exciting discovery that different IgG serodynamics can be monitored when using protein-based assays versus arrays comprising ECSPs. This DIVA microarray strategy should, in theory, work for any vaccine.

Supramolecular Assembly of ß-Cyclodextrin-Modified Polymer by Electrospinning with Sustained Antibacterial Activity.

Supramolecular assembly loading drug as biomedical materials is a research hotspot. Herein, we reported a supramolecular electrospun assembly constructed via the hydrophobic and hydrogen bonding interaction. The obtained results showed that the assembly by supramolecular electrospinning not only increased the interactions of multiple antibacterial active species including antibiotics, cationic polymers, and silver to form a flexible membrane with good mechanical strength but also indicated the dual effects of rapid doxycycline and polyethyleneimine release as well as a sustained Ag release. Interestingly, the assembly showed not only good degradability but also a high bacteriostatic efficacy toward Escherichia coli (E. coli) up to 99.9%. More importantly, the in vivo wound healing assay indicated that the assembly could promote the healing of uninfected, E. coli-infected, and even methicillin-resistant staphylococcus aureus-infected wounds. The current research provides a novel approach to construct a supramolecular assembly by electrospinning mechanically induced strong noncovalent interaction.

Surface properties of nucleolipids and photo-controlled release of hydrophobic guest molecules from their micellar aggregates.

Two series of nucleolipids have been designed and synthesized, one with a varying chain length (the dT-Cn series) and the other incorporating an aromatic photo-responsive moiety at the molecular hydrophobic and hydrophilic interface (the P-dT-Cn series). Surface tension measurements revealed the variations of critical micelle concentrations (CMCs) with the alkyl chain length and the incorporation of the photo-responsive segment. The P-dT-Cn series showed broadly lower CMCs and the minimum area per molecule (Amin) values because the π-π stacking between the additional aromatic rings favours more tight packing in the micelle formation. Both series showed similar surface tensions at the CMCs to conventional surfactants with equivalent molecular structures. Their micellar aggregates were used for encapsulation of hydrophobic Nile Red (NR). For the P-dT-Cn series, the encapsulated NR was released upon light irradiation and the controlled release was readily realized by controlling irradiation intensities or switching on and off irradiation. The integration of biocompatibility, complementary base recognition and photo-responsiveness makes the amphiphilic nucleolipids promising in biomedical and biotechnological applications.

Construction of a New Dual-Responsive Nano-Drug Delivery System for Matrix Metalloproteinases and Adenosine Triphosphate in Ovarian Cancer Using Nanomicelles.

In this manuscript we constructed a dual-responsive nano-drug delivery system for matrix metalloproteinases and ATP in ovarian cancer microenvironment. The nanomicelle PCL-DNA/DOX-Peptide-PEG was prepared by intercalating doxorubicin hydrochloride between C and G base pairs of DNA double helix structure. Another ATP-responsive nanomicelle PCL-DNA/DOX-PEG was prepared. Then we analyzed the characterization of nanomicelles (particle size, potential, surface morphology, etc.) and drug loading binding and drug release behavior. In addition, the effect of nanomicelles on the viability of mouse ovarian epithelial tumor cell ID-8 was detected by CCK-8 method. CCK-8 assay detected that different concentrations of carrier had no difference on the proliferation of ID-8 cells, and the survival rate of ID-8 cells by different concentrations of DOX preparations was statistically significant and the same results were observed in cytotoxicity comparison. Confocal microscopy showed that DOX in the drug-loaded micelle group was concentrated in the nucleus, while free DOX was concentrated in the cytoplasm. ID-8 cells took up the drug-loaded micelles faster. The semi-quantitative analysis of the DOX uptake of ID-8 cells with different treatments showed extremely significant statistical differences. In conclusion, the prepared self-assembled dual-responsive nanomicelle PCL-DNA/DOX-Peptide-PEG is novel anti-tumor agent, and is expected to have good tumor tissue penetration ability with a low toxicity.