Enhanced systemic and mucosal antibody responses to a model protein antigen after intranasal and intratracheal immunisation using Bacillus firmus as an adjuvant

Bacillus firmus, a non-pathogenic Gram positive (Gf) bacterium of the exter nal environment was investigated for immunomodulatory properties. It stimul ated an increase in anti-ovalbumin IgG in sera, bronchoalveolar lavages and intestinal washings after both intranasal (i.n.) and intratracheal (i.t.) immunisation, and enhanced anti-ovalbumin IgA in intestinal secretions and in bronchoalveolar lavage fluid after i.n. or i.t. immunisation, respective ly. The immunomodulatory effect of B. fir,nus on antibody formation was ant igen specific. (C) 2001 Elsevier Science B.V. All rights reserved.