title: Construction and immunological evaluation of dual cell surface display of HIV-1 gag and Salmonella enterica serovar Typhimurium FliC in Lactobacillus acidophilus for vaccine delivery.
abstract: Oral vaccines that elicit a mucosal immune response may be effective against human immunodeficiency virus type 1 (HIV-1) because its transmission occurs mainly at the mucosa. The aim of this study was to construct recombinant Lactobacillus for oral delivery of oral vaccines against HIV-1 and to evaluate their immunogenicity. A recombinant Lactobacillus acidophilus strain expressing the HIV-1 Gag on the bacterial cell surface was established by fusion with the signal peptide and anchor motif of a mucus binding protein (Mub) from L. acidophilus with or without coexpression of Salmonella enterica serovar Typhimurium flagellin (FliC) fused to a different Mub signal peptide and anchor. Using HEK293 cells engineered to express Toll-like receptor 5 (TLR5), the biological activity of FliC on the bacterial cell surfaces was determined. The surface-exposed flagellin retained its TLR5-stimulating activity, suggesting that the recombinant strain with Gag and FliC dual display might provide a different immunopotency than the strain expressing only Gag. The immunological properties of the recombinant strains were assessed by coculture with human myeloid dendritic cells (DCs). The heterologous antigens on the cell surface affected maturation and cytokine responses of DCs. Acquired immune responses were also investigated by intragastric immunization of mice. The enzyme-linked immunosorbent spot assay showed induction of gamma interferon-producing cells at local mucosa after immunization of mice with the Gag-producing strain. Meanwhile, the immunization with L. acidophilus displaying both Gag and FliC resulted in an increase of Gag-specific IgA-secreting cells. These results suggested that the Gag-displaying L. acidophilus elicited specific immune responses and the coexistence of FliC conferred an adjuvant effect on local IgA production.
authors: Department of Microbiology, Immunology, & Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
authors: Akinobu
authors: A
authors: Kajikawa
authors: Lin
authors: L
authors: Zhang
authors: Julie
authors: J
authors: Long
authors: Shila
authors: S
authors: Nordone
authors: Laura
authors: L
authors: Stoeker
authors: Alora
authors: A
authors: LaVoy
authors: Sara
authors: S
authors: Bumgardner
authors: Todd
authors: T
authors: Klaenhammer
authors: Gregg
authors: G
authors: Dean
mesh_terms: D016915:AIDS Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D000284:Administration, Oral; D000818:Animals; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D061505:Cell Surface Display Techniques / Q000379:methods*; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology; D005260:Female; D005408:Flagellin / Q000235:genetics / Q000276:immunology; D015497:HIV-1 / Q000235:genetics / Q000276:immunology; D006801:Humans; D007413:Intestinal Mucosa / Q000276:immunology; D007779:Lactobacillus acidophilus / Q000235:genetics*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D012486:Salmonella typhimurium / Q000235:genetics / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000235:genetics / Q000276:immunology
chemical_list: D016915:AIDS Vaccines; D001428:Bacterial Vaccines; D014614:Vaccines, Synthetic; D054301:gag Gene Products, Human Immunodeficiency Virus; D005408:Flagellin