title: In situ delivery of passive immunity by lactobacilli producing single-chain antibodies.
abstract: Lactobacilli have previously been used to deliver vaccine components for active immunization in vivo. Vectors encoding a single-chain Fv (scFv) antibody fragment, which recognizes the streptococcal antigen I/II (SAI/II) adhesion molecule of Streptococcus mutans, were constructed and expressed in Lactobacillus zeae (American Type Culture Collection (ATCC) 393). The scFv antibody fragments secreted into the supernatant or expressed on the surface of the bacteria showed binding activity against SAI/II in enzyme-linked immunosorbent assay (ELISA), and surface scFv-expressing lactobacilli agglutinated SAI/II-expressing S. mutans in vitro without affecting the corresponding SAI/II knockout strain. Lactobacilli expressing the scFv fragment fused to an E-tag were visualized by scanning electron microscopy (SEM) using beads coated with a monoclonal anti-E-tag antibody, and they bound directly to beads coated with SAI/II. After administration of scFv-expressing bacteria to a rat model of dental caries development, S. mutans bacteria counts and caries scores were markedly reduced. As lactobacilli are generally regarded as safe (GRAS) microorganisms, this approach may be of considerable commercial interest for in vivo immunotherapy.
authors.affiliation: Center for Oral Biology, Karolinska Institutet at NOVUM and Division of Clinical Immunology, Karolinska Institutet at Huddinge Hospital, SE-141 86 Huddinge, Sweden.
authors.forename: Carina
authors.initials: C
authors.lastname: Krüger
authors.forename: Yanzhong
authors.initials: Y
authors.lastname: Hu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Pan
authors.forename: Harold
authors.initials: H
authors.lastname: Marcotte
authors.forename: Anna
authors.initials: A
authors.lastname: Hultberg
authors.forename: Dipu
authors.initials: D
authors.lastname: Delwar
authors.forename: Philip J
authors.initials: PJ
authors.lastname: van Dalen
authors.forename: Peter H
authors.initials: PH
authors.lastname: Pouwels
authors.forename: Rob J
authors.initials: RJ
authors.lastname: Leer
authors.forename: Charles G
authors.initials: CG
authors.lastname: Kelly
authors.forename: Craig
authors.initials: C
authors.lastname: van Dollenweerd
authors.forename: Julian K
authors.initials: JK
authors.lastname: Ma
authors.forename: Lennart
authors.initials: L
authors.lastname: Hammarström
mesh_terms: D000818:Animals; D003731:Dental Caries / Q000276:immunology / Q000517:prevention & control; D015964:Gene Expression Regulation, Bacterial; D007135:Immunoglobulin Variable Region / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D007780:Lacticaseibacillus casei / Q000235:genetics* / Q000276:immunology*; D008957:Models, Genetic; D051381:Rats; D017207:Rats, Sprague-Dawley; D013295:Streptococcus mutans / Q000276:immunology / Q000502:physiology
chemical_list: D007135:Immunoglobulin Variable Region