Lactobacillus as Vaccine-vectors
Lactobacillus species are symbiotic bacteria that have long been considered probiotic microorganisms and are generally regarded as safe (GRAS) for human consumption. In recent years, recombinant lactobacilli have gained increasing attention as vectors for the delivery of therapeutic and prophylactic molecules via the intranasal, oral, or genital mucosal surfaces. Due to its good properties, lactobacilli have become an attractive potential alternative to other mucosal delivery systems, such as microspheres, liposomes, nanoparticles, immunostimulating complexes, and attenuated pathogens.
Introduction of Lactobacillus
Lactobacillus is a diverse variety of more than 100 species and consists of Gram-positive, lactic acid commensal and dietary bacterium that colonizes the gastrointestinal (GI) and vagina and have been shown to aid in maintaining mucosal barrier function. homeostasis, and the tolerogenic environment of the mucosa. Lactobacilli are considered to have a GRAS (generally considered safe) state, and many species have been described as having probiotic characteristics. Some select lactobacilli are increasingly recognized as health regulators and are of great interest as microbes that can be used as functional food ingredients to promote health and as delivery vehicle for vaccines and biotherapeutics. Several species of Lactobacillus (Lactobacillus casei, Lactobacillus plantarum, Lactobacillus gasseri, and Lactobacillus acidophilus) have been investigated as antigen delivery vehicles against a spectrum of infectious agents, but an immune response to different lactobacilli can vary widely depending on the species or subspecies of Lactobacillus.
Design of Lactobacillus Vectors Based Vaccines
Creative Biolabs offers a variety of constitutive or inducible expression systems through a variety of modifications that can effectively increase protein translation efficiency and enhance protein expression. Key features of cloning vectors for the delivery of antigens involve promoter sequences that allow either constitutive or inducible expression. The widely used inducible expression system is nisin-controlled expression (NICE) system, which is particularly suitable for use in Lactobacillus and systems based on sugar metabolism with promoters that are regulated by catabolite repression such as the xylose promoter. Moreover, these vectors can contain secretion and anchoring signals that allow expression of the protein in different cellular compartments. When similar expression systems are used in different Lactobacillus strains, it is important to know that promoters can have different levels of activity depending on the strain in which they are used, and that the replication efficiency and plasmid copy number can be different.
The Features of Lactobacillus Vectors
Lactobacilli have several features that make them potentially better candidates for oral vaccination. These features include the following:
- Being of species-specific origin and nonpathogenic/nontoxigenic/noninvasive
- Lack of antibiotic resistance genes
- Resistance to acid and bile
- Adhesion to epithelial cells
- Transient presence in the gastrointestinal tract
- Production of antibacterial substances
- Modulating immune responses and having a positive effect on host metabolism
The Advantages of Lactobacillus Vectors
- Highly secure
- Can express numerous heterologous proteins
- Ability to elicit the production of secretory IgA
- Confer protection against infections at mucosal surfaces and prevent antigen degradation
With years of experience and state-of-the-art technology in bacterial vaccine vectors, Creative Biolabs has developed a safe and efficient vaccine vector by multiple strategies. If you are interested in any of our services related to Lactobacillus vaccine vectors, please feel free to contact us.
All of our products can only be used for research purposes. These vaccine ingredients CANNOT be used directly on humans or animals.
