Differences in Antigenicity of Human IgG Produced by Three Established Lymphocytoid Cell Lines from a Single Individual

摘要

Three lymphocytoid cell lines established from peripheral leucocytes of a single individual were found to produce IgG of the kappa light chain type and of the G1-heavy chain subclass. These IgG globulins showed a limited electrophoretic mobility in slow γ2 region. Rabbit antisera against each IgG revealed the presence of idiotypic determinants in each IgG indicating the clonal nature of IgG-producing cells in these cell lines. The idiotypic determinants in one IgG were clearly distinguishable from those in the other two IgG globulins, while those in the latter two could not be distinguished one from the other. Thus, the two cell lines producing these mutually indistinguishable IgG globulins seem to have been derived from stem cells belonging to the identical or very closely related clones although they were established from different blood samples. The idiotypic determinants were found to be present in the Fab portion of the IgG molecules.