It was shown that plasmid pUC19 DNA stimulates in vitro proliferation of CB
A mouse splenocytes in a dose-dependent manner. Stimulation effect of the p
lasmid DNA is additive with Con A or LPS, synergistic with PMA and is inhib
ited by nonimmunogenic phosphodiester oligonucleotides and Fab fragments of
antimouse Ig antibodies. These data and the data of affinity labelling of
ODN-binding proteins indicate that immunoglobulin receptors are involved in
DNA-induced lymphocyte activation.