Yersinia enterocolitica as Vaccine-vectors

Yersinia enterocolitica (Y. enterocolitica) is an enteric pathogen that can invade intestinal tissues, resisting host clearance mechanisms. The invasion of entero cells by Y. enterocolitica is largely dependent on the presence of a virulence plasmid, which encodes the synthesis of several virulence determinants. These proteins are synthesized during the invasive phase and stimulate strong antibody responses. With an in-depth understanding of Y. enterocolitica, several recombinant Y. enterocolitica strains have been used as carriers for heterologous antigens, leading to the elicitation of efficient and protective immune responses at systemic and mucosal levels.

Introduction of Yersinia enterocolitica

Yersinia enterocolitica (Y. enterocolitica), belonging to the genus Yersinia of the family Enterobacteriaceae, is a food- and water-borne human pathogen isolated from the intestinal tract of many animal species and humans. According to the difference in antigen O structure, Y. enterocolitica is divided into 70 serotypes belonging to 6 biotypes, 1A, 1B, 2-5. Y. enterocolitica contains both nonvirulent and virulent isolates, most Y. enterocolitica strains isolated to date from free-living animals or the environment belong to biotype 1A and are non-pathogenic.

The Principle of Yersinia enterocolitica as Vaccine Carriers

Y. enterocolitica has the ability to deliver bacterial effector proteins called Yops inside eukaryotic cells. These effector Yops allow bacteria to survive and proliferate extracellularly in the lymphoid system of the host. The Yop effector proteins and their machinery exported from bacteria and transported into eukaryotic cells are all encoded by a 70 kb virulence plasmid, which is called pYV in Y. enterocolitica. The entire system and regulatory control are called Yop virulon. Six Yop effectors are known: YopE, YopH, YopM, YopT, YopO/YpkA, and YopP/YopJ. Yops are secreted by a complex type III secretion device comprising more than 22 Ysc proteins. Translocation of the effector Yops across eukaryotic membranes requires four additional bacterial proteins called translocation proteins: YopB, YopD, LcrV, and LcrG.

In order to translocate Yops to eukaryotic cells, the bacteria must adhere to the surface of eukaryotic cells. Attachment induces an increase in the opening of the Ysc secretion channel and the production of Yops. The main determinant of adhesion in Y. enterocolitica is YadA. YadA is encoded by the virulence plasmid itself and binds to a variety of extracellular proteins, including fibronectin and collagen. There may be a receptor on the surface of eukaryotic cells that interacts with a ligand on the bacteria surface and cause Yop injection signals. In Y. enterocolitica, YopN, TyeA and/or LcrG have the potential to become bacterial ligands, since bacteria carrying mutations in any of these genes have a deregulated Yop secretion phenotype.

Our Design for Yersinia enterocolitica as Vaccine-vectors

Strains

The Y. enterocolitica translocation host strain ΔAHOPEMTRQ (strain MRS40(pNG4001)) carries mutations in each of the effector Yops (YopH, YopO. YopP, YopE, YopM, and YopT), as well as in YopR and YopO. This strain deleted the yscH gene encoding YopR and the yopQ gene and secreted the transporter Yops (YopB, LcrV, YopD, and YopN) into the medium. This combination of Y. enterocolitica translocation strain and vector permit the effects of the fusion protein inside eukaryotic cells without interference from the action of the Yop effectors themselves.

Construction of expression vector

Y. enterocolitica stains allow delivery into eukaryotic cells of heterologous proteins fused to the minimal N-terminal secretion/translocation signal of YopE. Creative Biolabs designed the expression vector containing a strong yopE promoter with optimal SD at the best interval from the start codon and the first 16 codons of yopE, followed by three restriction sites for cloning. In the Yop effector multi-mutant strain, the first 15 amino acids of YopE are sufficient to direct the translocation of the hybrid protein into eukaryotic cells. By cloning of the appropriate genes in frame with these codons of yopE, this plasmid allows expression of fusion proteins in.Y. enterocolitica and their subsequent secretion and translocation into eukaryotic cells.

Y. enterocolitica has been considered as an attractive candidate for use as a vaccine vector for inducing mucosal immunity against heterologous antigens. With years of experience and advanced vaccine technology platform, Creative Biolabs has developed a variety of engineered and attenuated Y. enterocolitica vectors for vaccine delivery based on the needs of different clients. If you have any needs in this regard, please contact us as soon as possible.

All of our products can only be used for research purposes. These vaccine ingredients CANNOT be used directly on humans or animals.