Anti-Peptide Antibody Production Elicited by in VitroImmunization of Human Peripheral Blood Mononuclear Cells

Human monoclonal antibodies have great potential for use in the treatment of various diseases. We have established an in vitroimmunization protocol for inducing antigen-specific antibody production from human peripheral blood mononuclear cells (PBMCs). In the in vitroimmunization protocol, PBMCs are pretreated with L-leucyl-L-leucine methyl ester (LLME) to remove suppressive cells, and are sensitized and cultured with a soluble antigen in the presence of IL-2, IL-4 and muramyl dipeptide for 8 d, and then an antigen-specific antibody is produced. In this study, we examined the novel possibility of an in vitroimmunization protocol, specifically, whether LLME-treated PBMCs can be sensitized with a peptide antigen to produce an anti-peptide antibody. The results indicate that antigen-specific immune responses were elicited by a peptide antigen derived from rice allergen, a cholera toxin B subunit, and TNF-α as a sensitizing antigen in in vitroimmunization. These results suggest that the in vitroimmunization protocol is applicable in the generation of an anti-peptide antibody against various antigens, including food allergens, foreign antigens, and self-antigens.