Peripheral blood specific antibody-forming cells after oral stimulation with a ribosomal vaccine

A double-blind study was performed in 12 healthy volunteers in order to determine whether circulating immunocytes are present after oral immunization. Sequential samples of peripheral blood were collected at various times after ingestion of a ribosome vaccine (D53) or placebo. Immunoglobulin-containing cells were identified in immunofluorescence and specific antibody-forming cells were detected in agarose ELISA-spot. Higher numbers of both types of cells were observed in the group of individuals receiving ribosomal extracts. An open study allowed a better approach to the kinetics of this phenomenon, related to the release of activated B-cells from Peyer's patches upon antigenic stimulation. This methodological approach has been described in animal models but seldom reported in humans.