Oral priming of mice by recombinant spores of Bacillus subtilis.
Recombinant Bacillus subtilis spores were employed as a vaccine delivery system in a heterologous mucosal priming-parenteral boosting vaccination strategy in the mouse model. BALB/c and C57BL/6 mice were orally immunised with recombinant spores expressing tetanus toxin fragment C (TTFC) fused to the spore outer coat protein CotB, and then subcutaneously boosted with soluble TTFC (without adjuvant). Two weeks after boosting, a significantly higher serum TTFC-specific IgG response was stimulated in mice primed with recombinant spores (antibody concentration of 2600 +/- 915 in C57BL/6 and 1200 +/- 370 ng/ml in BALB/c) compared to mice inoculated with wild type spores (650 +/- 250 and 250 +/- 130 ng/ml, respectively). IgG subclass analysis showed a prevalence of IgG1 and IgG2b, indicative of a Th2 type of immune response. Oral administration of recombinant spores stimulated also a significant local TTFC-specific IgA response. These data show that recombinant spores of B. subtilis are able to prime the immune system by the oral route, and that a combined mucosal/parenteral strategy can stimulate both local and systemic antigen-specific immune responses.
Laboratorio di Microbiologia Molecolare e Biotecnologia (LAMMB), Dipartimento di Biologia Molecolare, Università di Siena, Policlinico Le Scotte V lotto, piano 1, 53100 Siena, Italy.
Annalisa
A
Ciabattini
Riccardo
R
Parigi
Rachele
R
Isticato
Marco R
MR
Oggioni
Gianni
G
Pozzi
D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis / Q000096:biosynthesis; D001412:Bacillus subtilis / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology; D005260:Female; D007070:Immunoglobulin A / Q000096:biosynthesis / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D011994:Recombinant Proteins / Q000276:immunology; D013171:Spores, Bacterial / Q000276:immunology*; D013744:Tetanus Toxin / Q000276:immunology
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; C439051:CotB protein, Bacillus subtilis; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D013744:Tetanus Toxin