Preparation of graphene oxide-stabilized Pickering emulsion adjuvant for Pgp3 recombinant vaccine and enhanced immunoprotection against Chlamydia Trachomatis infection

Progress towards effective vaccines for Chlamydia trachomatis

PURPOSE OF REVIEW

Effective vaccines to prevent sexually transmitted Chlamydia trachomatis (Ct) infection have eluded researchers for decades. However, recent studies of a promising vaccine in human trials, and emerging understanding of the complexity of the natural immune response to infection have provided hope for the eventual approval of a vaccine. This review highlights recent progress toward developing effective vaccines for Ct.

RECENT FINDINGS

In 2019, the first-in-human Ct vaccine, CTH522, Phase I/IIB trial was reported. Recent studies of this vaccine and its derivatives have further established CTH522 as the lead vaccine against sexually transmitted Ct. A variety of vaccines have entered the preclinical development pipeline, with researchers reporting efforts to target non-MOMP antigens, include novel adjuvants in vaccine formulations, and use alternative routes of administration to increase efficacy.

SUMMARY

While the approval of a vaccine for Ct is closer than ever, the need for careful consideration of future implementation is especially important for the successful clinical translation of Ct vaccines into humans.

A Narrative Review on the Promising Potential of Graphene in Vaccine Design: Evaluating the Benefits and Drawbacks of Carbon Nanoplates in Nanovaccine Production

Graphene, a two-dimensional material consisting of a single layer of carbon atoms arranged in a honeycomb lattice, has shown great potential in various fields, including biomedicine. When it comes to vaccine development, graphene can offer several advantages due to its unique properties. Potential applications of graphene in vaccine development include improved vaccine delivery, adjuvant properties, improved vaccine stability, improved immune response, and biosensing capabilities. Although graphene offers many potential benefits in vaccine development, there are also some drawbacks and challenges associated with its use. Although graphene shows promising potential for vaccine development, overcoming the challenges and limitations associated with its use is critical to realizing its full potential in the field of immunization. Further research and development efforts are needed to overcome these drawbacks and take advantage of graphene for improved vaccine formulations. In this review, we focus on the advantages and disadvantages of graphene for vaccine development.

A novel chimeric recombinant FliC-Pgp3 vaccine promotes immunoprotection against Chlamydia muridarum infection in mice

The Pgp3 subunit vaccine elicits immune protection against Chlamydia trachomatis infection, but additional adjuvants are still required to enhance its immunoprotective efficacy. Flagellin can selectively stimulate immunity and act as an adjuvant. In this research, the FliC-Pgp3 recombinant was successfully expressed and purified. Tri-immunization with the FliC-Pgp3 vaccine in Balb/C mice induced rapid and persistent germinal center B-cell response and Tfh differentiation, promoting a significantly higher IgG antibody titer compared to the Pgp3 group. FliC-Pgp3 immunization primarily induced Th1-type cellular immunity, leading to higher levels of IFN-γ, TNF-α, and IL-2 secreted by CD4+ T cells than in Pgp3-vaccinated mice. Chlamydia muridarum challenge results showed that FliC-Pgp3-vaccinated mice exhibited more rapid clearance of Chlamydia muridarum colonization in the lower genital tract, ensuring a lower hydrosalpinx rate and cumulative score. Histological analysis showed reduced dilation and inflammatory infiltration in the oviduct and uterine horn of FliC-Pgp3-vaccinated mice compared to the PBS and Pgp3 control. Importantly, tri-immunization with FliC-Pgp3 effectively activated CD4+ T cells and dendritic cells, as confirmed by the adoptive transfer, resulting in better immune protection in recipient mice. In summary, the novel FliC-Pgp3 chimeric is hoped to be a novel vaccine with improved immunoprotection against Chlamydia muridarum.

Pickering emulsions stabilized by soybean protein isolate/chitosan hydrochloride complex and their applications in essential oil delivery

In this work, fabrication of soybean protein isolate (SPI)/chitosan hydrochloride (CHC) composite particles stabilized O/W Pickering emulsions using soybean oil as an oil phase was optimized by examining the effects of pH, SPI/CHC mass ratio, SPI/CHC composite particle concentration and oil phase fraction on the stability of the emulsions. The results showed that under the conditions of SPI/CHC mass ratio 1:1, pH 4 and particle concentration 2 %, the SPI/CHC composite particles could stabilize the emulsions with oil phase fraction up to 80 %. At an oil phase fraction of 60 %, the emulsions had a minimum particle size. The microstructure, storage and oxidation stabilities and rheological properties of the emulsions were determined. Using this SPI/CHC composite particle-stabilized Pickering emulsion template, citrus essential oil (CEO) Pickering emulsion (CEOP) was prepared. CEOP was found to markedly inhibit two food-related microorganisms, Staphylococcus aureus and Escherichia coli. In addition, the CEOP emulsion dilution (containing 4500 μL CEO/L) not only improved the water solubility of CEO, but also effectively retarded the browning and bacterial growth of fresh-cut apple. The SPI/CHC-stabilized Pickering emulsion template constructed in this work provides a promising alternative for the delivery of antimicrobial essential oils in the food industry.