A human-mouse hybridoma clone #86 secreting IgM-class human monoclonal antibody to peanut allergen protein Ara h1 was newly established. To detect an antibody-binding sequence (epitope) on Ara h1, the monoclonal antibody #86 was reacted with multi-pin apparatus with a series of peptides synthesized from the amino acid sequence of Ara h1. The antibody #86 was found to bind to a peptide with amino acid sequence of 481EEEEDEDEEEEGSNREVRRY500. Further analysis with shorter pin-peptides with ten amino acid-long showed that the peptides reacted with the antibody #86 contained a sequence of 485DEDEEEE491. This might be an essential linear sequence of this epitope. When the 485DED487 part of the peptide was replaced by alanine, decreased binding of antibody #86 was observed.

We obtained a stable human-mouse hybridoma clone 4701-1 secreting IgM class human monoclonal antibody to Japanese cedar pollen allergen Cry j1. A pin-peptide enzyme-linked immunosorbent assay (ELISA) with synthesized pentadeca peptides showed a peptide with an amino acid sequence of LYTVT NSDDD PVNPA was found to be positive. Detailed analysis with deca to tetra peptides indicated that an amino acid sequence of TVTN was an essential sequence for antibody binding. When N (Asn) was substituted with A (Ala) of the TVTN epitope, the resulting peptide did not have antibody binding ability. We concluded that the TVTN sequence might have a very important role in early recognition of Cry j1 allergen by Cry j1-specific B cells, which act as antigen presenting cells.