Wa-VP4* as a candidate rotavirus vaccine induced homologous and heterologous virus neutralizing antibody responses in mice, pigs, and cynomolgus monkeys.

Group A rotavirus (RVA) is the primary etiological agent of acute gastroenteritis (AGE) in children under 5 years of age. Despite the global implementation of vaccines, rotavirus infections continue to cause over 120,000 deaths annually, with a majority occurring in developing nations. Among infants, the P[8] rotavirus strain is the most prevalent and can be categorized into four distinct lineages.

Orchestrated Codelivery of Peptide Antigen and Adjuvant to Antigen-Presenting Cells by Using an Engineered Chimeric Peptide Enhances Antitumor T-Cell Immunity.

The intrinsic pharmacokinetic limitations of traditional peptide-based cancer vaccines hamper effective cross-presentation and codelivery of antigens (Ag) and adjuvants, which are crucial for inducing robust antitumor CD8+ T-cell responses. In this study, we report the development of a versatile strategy that simultaneously addresses the different pharmacokinetic challenges of soluble subunit vaccines composed of Ags and cytosine-guanosine oligodeoxynucleotide (CpG) to modulate vaccine efficacy via translating an engineered chimeric peptide, eTAT, as an intramolecular adjuvant. Linking Ags to eTAT enhanced cytosolic delivery of the Ags.

Bivalent rotavirus VP4∗ stimulates protective antibodies against common genotypes of human rotaviruses.

Non-replicating rotavirus vaccines are an alternative strategy to improve the efficacy and safety of rotavirus vaccines. The spike protein VP4, which could be enzymatically cleaved into VP8∗ and VP5∗, is an ideal target for the development of recombinant rotavirus vaccine. In our previous studies, we demonstrated that the truncated VP4 (aa26-476, VP4∗) could be a more viable vaccine candidate compared to VP8∗ and VP5∗.

Generation and characterization of mouse monoclonal antibodies against the VP4 protein of group A human rotaviruses.

Human rotaviruses (RVs) are the leading cause of severe diarrhea in infants and young children worldwide. Among the structural proteins, as a spike protein, rotavirus VP4 plays a key role in both viral attachment and penetration. Currently, studies on monoclonal antibodies (mAbs) against VP4 are limited.

Establishment of Sandwich ELISA for Quality Control in Rotavirus Vaccine Production.

Non-replicating rotavirus vaccines are alternative strategies that may improve the protective efficacy of rotavirus vaccines in low- and middle-income countries. The truncated spike protein VP4 (aa26-476, VP4*)was a candidate antigen for the development of recombinant rotavirus vaccines, with higher immunogenicity and protective efficacy compared to VP8* and VP5* alone. This article describes the development of three genotype-specific sandwich ELISAs for P[4], P[6], and P[8]-VP4*, which are important for quality control in rotavirus vaccine production.

Efficient intracellular delivery of proteins by a multifunctional chimaeric peptide in vitro and in vivo.

Protein delivery with cell-penetrating peptide is opening up the possibility of using targets inside cells for therapeutic or biological applications; however, cell-penetrating peptide-mediated protein delivery commonly suffers from ineffective endosomal escape and low tolerance in serum, thereby limiting in vivo efficacy. Here, we present an intracellular protein delivery system consisting of four modules in series: cell-penetrating peptide, pH-dependent membrane active peptide, endosome-specific protease sites and a leucine zipper. This system exhibits enhanced delivery efficiency and serum tolerance, depending on proteolytic cleavage-facilitated endosomal escape and leucine zipper-based dimerisation.

The distinct impact of maternal antibodies on the immunogenicity of live and recombinant rotavirus vaccines.

A high titre of maternal antibodies is one of the possible factors associated with decreased rotavirus vaccine efficacy in low-income countries where rotavirus-associated morbidity and mortality are high. Although some studies show a negative correlation between maternal antibody levels and seroconversion after vaccination, withholding breastfeeding does not improve rotavirus vaccine efficacy. Different types of recombined vaccines were developed as an alternative to produce higher protection in developing areas.

[Polymerization and evaluation of the protective efficacy of rotavirus VP4* proteins].

In previous studies, we found that truncated rotavirus VP4* (aa 26-476) could be expressed in soluble form in Escherichia coli and confer high protection against rotavirus in the mouse mode. In this study, we further improved the immunogenicity of VP4* by polymerization. The purified VP4* was polymerized through incubation at 37 ℃ for 24 h, and then the homogeneity of the particles was analyzed by HPLC, TEM and AUC, while the thermal stability and antigenicity was analyzed by DSC and ELISA, respectively.

Expression and characterization of a novel truncated rotavirus VP4 for the development of a recombinant rotavirus vaccine.

The outer capsid protein VP4 is an important target for the development of a recombinant rotavirus vaccine because it mediates the attachment and penetration of rotavirus. Due to the poor solubility of full-length VP4, VP8 was explored as candidate rotavirus vaccines in the past years. In previous studies, it has been found that the N-terminal truncated VP8 protein, VP8-1 (aa26-231), could be expressed in soluble form with improved immunogenicity compared to the core of VP8 (aa65-223).

Effects of Site-Mutations Within the 22 kDa No-Core Fragment of the Vip3Aa11 Insecticidal Toxin of Bacillus thuringiensis.

Bacillus thuringiensis vegetative insecticidal proteins (VIPs) are not homologous to other known Cry proteins, and they act against lepidopteran larvae via a unique process. All reported studies on the mode of action of Vip3 proteins have been performed on the Vip3A family, mostly on the Vip3Aa subfamily. Vip3Aa proteins are activated by midgut proteases, and they cross the peritrophic membrane and bind specific proteins in apical membrane epithelial midgut cells, which results in pore formation and, eventually, death to the insects.