Oral Immunization with RecombinantLactobacillus plantarumInduces a Protective Immune Response in Mice with Lyme Disease

Abstract

Mucosal immunization is advantageous over other routes of antigen delivery because it can induce both mucosal and systemic immune responses. Our goal was to develop a mucosal delivery vehicle based on bacteria generally regarded as safe, such as Lactobacillus spp. In this study, we used the Lyme disease mouse model as a proof of concept. We demonstrate that an oral vaccine based on live recombinant Lactobacillus plantarum protects mice from tick-transmitted Borrelia burgdorferi infection. Our method of expressing vaccine antigens in L. plantarum induces both systemic and mucosal immunity after oral administration. This platform technology can be applied to design oral vaccine delivery vehicles against several microbial pathogens.Lactic acid bacteria are naturally associated with mucosal surfaces, particularly the gastrointestinal tract, and are also indigenous to food-related habitats, including plants, wine, milk, and meat. These gram-positive bacteria include both important pathogens, e.g., several Streptococcus species, and extremely valuable nonpathogenic species that have been used since ancient times for food and feed fermentation (11,37,58). The host is highly adapted to the presence of commensal intestinal bacteria (36). There is evidence that some strains of lactic acid bacteria have a favorable influence on physiologic and pathological processes of the host due to their specific health-promoting probiotic characteristics that relate to modulation of the immune system (15,36,41). Some strains of lactic acid bacteria polarize the naïve immune system by skewing it toward Th1 responses (41, 56).There have been a number of reports of oral vaccine candidates established from genetically modified pathogenic bacteria, such as Salmonella and Listeria species (1, 2, 30, 45, 52), or commensal bacteria, such as Lactococcus lactis and Lactobacillus species (27,31,32,60). The latter are food-grade bacteria that have GRAS status (generally regarded as safe). While both pathogenic and commensal bacteria have advantages and disadvantages as mucosal delivery vehicles, lactic acid bacteria are preferable in terms of safety and a lower risk of side effects (27,47). Presentation of antigens on the surface of lactobacilli is attractive for vaccine design, especially because the peptidoglycan layer of some strains appears to exhibit natural immuno-adjuvanticity (33,35,44,46). Thus, these species are excellent candidates for the development of safe mucosal delivery vehicles of prophylactic and therapeutic molecules. Of the Lactobacillus strains previously used for vaccine delivery, we chose L. plantarum because there is evidence that this strain is a better agent for vaccination with tetanus toxin fragment C (TTFC) than L. casei or L. lactis (22,53).Lyme disease is the most prevalent vector-borne infectious disease in the United States. A vaccine administered via needle inoculation and based on outer surface protein A (OspA) has proved effective in preventing Borrelia burgdorferi infection in animals and humans (7,10,(16)(17)...

Oral Immunization with Escherichia coli Expressing a Lipidated Form of LigA Protects Hamsters against Challenge with Leptospira interrogans Serovar Copenhageni

“…Oral immunization has been shown to provide protection against a variety of bacterial pathogens, including Vibrio cholerae, Salmonella enterica serovar Typhi, and Borrelia burgdorferi (12)(13)(14)(15). Protection of mice against B. burgdorferi infection by oral immunization has been achieved using either Lactobacillus plantarum (12) or Escherichia coli (15) as delivery vehicles for the immunogen, OspA. Inclusion of the 16-amino-acid lipoprotein signal peptide of OspA tags the protein for translocation across the cytoplasmic membrane and subsequent lipidation.…”

“…Orally delivered vaccines have several advantages over other routes of antigen delivery, including convenience, costeffectiveness, and, most importantly, induction of both local and systemic immune responses (11). Oral immunization has been shown to provide protection against a variety of bacterial pathogens, including Vibrio cholerae, Salmonella enterica serovar Typhi, and Borrelia burgdorferi (12)(13)(14)(15). Protection of mice against B. burgdorferi infection by oral immunization has been achieved using either Lactobacillus plantarum (12) or Escherichia coli (15) as delivery vehicles for the immunogen, OspA.…”

Mucosal and Systemic Immune Responses Induced by Recombinant Lactobacillus spp. Expressing the Hemagglutinin of the Avian Influenza Virus H5N1

“…Their abilities to transit through the stomach intact and to associate closely with the intestinal epithelium, combined with their immunomodulatory properties, have made Lactobacillus spp. attractive candidates as live vehicles for the delivery of immunogens to the intestinal mucosa (6,12). It was recently shown that specific Lactobacillus species can induce inflammatory responses against infection, increase IgA production, activate monocytic lineages (4,16), and regulate the balance of the Th1 and Th2 pathways (2,30).…”

Expression and Secretion of Cholera Toxin B Subunit in Lactobacilli

“…Taking advantage of these characteristics, previous studies using recombinant DNA technology have used lactobacilli to express or secrete useful proteins. 3,5) Cholera is a diarrheal infection disease caused by Vibrio cholerae, with an estimated 3-5 million cholera cases and 100000-120000 deaths due to cholera every year. 6) Cholera toxin (CT) is comprised of a toxic A (CTA) subunit and a pentameric non-toxic B (CTB) subunit.…”