IgG subclass distribution in juvenile human tonsil: IgG3 and IgG4 results of specific antibody production using synthetic peptides.

A decapeptide with a sequence corresponding to a part of the hinge region of human IgG3 was used to prepare a mouse monoclonal antibody (Mab 330-2.2). The Mab recognized IgG3 in ELISA only when the IgG3 was denatured by mild heat. Mab specificity in immunohistochemistry was calibrated with a number of reference Mabs obtained through a WHO/IUIS collaborative study. Finally, Mab 330-2.2 was used in conjunction with a set of other isotype specific Mabs to study the (sub)class distribution of cytoplasmic Ig containing cells in palatine tonsil. IgG3 within the IgG class was strongly over-represented in our tonsil material if compared to the representation of IgG3 in serum.