Immunomodulation by Bacillus subtilis spores

This study was undertaken in order to investigate the immunomodulatory effect of heat-killed Bacillus subtilis spores as well as of one soluble and one insoluble fraction obtained after their mechanical breakage. The results demonstrate that heat-killed spores, the soluble and the insoluble fraction enhance the primary PFC response to T-dependent antigens such as SRBC and HRBC, but not to T-independent antigens such as Ficoll-TNP. However, the same doses capable of enhancing the production of antibodies against T-dependent antigens were unable to modify the host CMI, evaluated in terms of contact sensitivity to oxazolone.