Display of heterologous antigens on the Bacillus subtilis spore coat using CotC as a fusion partner

Bacillus subtilis spores: A novel microparticle adjuvant which can instruct a balanced Th1 and Th2 immune response to specific antigen

“…and increased CD4 + and CD8 + T cell responses were clearly demonstrated. These immune responses were directly attributable to the adjuvant properties conferred by the spore as opposed to the probiotic properties of live replicating bacteria of B. subtilis [32] or immunostimulatory activity of bacterial cells derived from live B. subtilis vectors currently under investigation [33][34][35]. Our findings raise the question, how does a spore, tolerated orally in man and of no known pathogenicity [18] efficiently modulate both the quantity and quality of the immune response to a co-administered antigen?…”

Bacillus subtilis as a tool for vaccine development: from antigen factories to delivery vectors

“…Two spore coat proteins, CotB and CotC, have been used to display tetanus toxin fragment C (TTC) of Clostridium tetani and the B subunit of the heat labile toxin (LTB) produced by some enterotoxigenic E. coli strains (ETEC) as fused proteins expressed on the surface of B. subtilis spores , Duc et al 2003a, Mauriello et al 2004 (Table I). Both antigens were expressed as C-terminal fusions with the Cot proteins, which are by themselves anchored at the outer layer of the spore coat at a number of approximately 1,000 molecules/spore , Duc et al 2003a.…”

“…Both antigens were expressed as C-terminal fusions with the Cot proteins, which are by themselves anchored at the outer layer of the spore coat at a number of approximately 1,000 molecules/spore , Duc et al 2003a. In contrast to the attempts to employ B. subtilis strains as expression systems of heterologous proteins for subunit vaccines, the genes encoding hybrid spore coat proteins were integrated into specific sites at the bacterial chromosome, which conferred stability to the expression of the recombinant genes (Duc et al 2003a, Mauriello et al 2004. Mice orally treated with three consecutive daily doses of recombinant spores, given three times at intervals of two weeks, developed statistically significant secreted fecal (IgA) and serum (IgG) antibody levels which, at least in the case of TTC, could confer protection to mice challenged with lethal doses of the toxin (Duc et al 2003a, Mauriello et al 2004.…”

“…FERREIRA, RITA C.C. FERREIRA and WOLFGANG SCHUMANN 2003a, Mauriello et al 2004). Such features could be attributed to the ubiquitous presence of spores in the environment and its chemical composition that is devoid of compounds known to induce inflammatory responses in mammal hosts.…”

“…Such features could be attributed to the ubiquitous presence of spores in the environment and its chemical composition that is devoid of compounds known to induce inflammatory responses in mammal hosts. Thus, oral immunization regimens with recombinant B. subtilis spores require high antigen loads (above 10 10 spores/dose) and repeated immunizations (Duc et al 2003a, Mauriello et al 2004. Indeed some experimental evidences suggested that most of the local and systemic immunogenicity of recombinant B. subtilis spores is triggered during the intracellular germination and transient persistence of the nascent vegetative cell in the phagosome of phagocytic cells, as macrophages (Duc et al 2003b.…”