Generation of human monoclonal antibodies against Propionibacterium acnes by applying the phage display method to human peripheral blood mononuclear cells immunized in vitro

Propionibacterium acnes is a gram-positive, non-spore-forming, rod-shaped bacterium that is often detected in normal human skin flora. P. acnes has been associated with many diseases. In this study, we attempted to generate anti-P. acnes human monoclonal antibodies. A phage antibody library was first generated from human peripheral blood mononuclear cells immunized in vitro with P. acnes using the phage display method, and P. acnes-specific phage antibodies were obtained using solid phase panning. Antigen-specific variable region genes were then amplified and recombined into vectors expressing human IgG antibodies. The results indicated that the recombinant human IgG antibodies exhibited P. acnes-specific binding. This study demonstrates that the combined use of an in vitro immunization protocol and the phage display method enables the generation of human monoclonal antibodies against pathogenic bacteria and toxic antigens.