Antibodies that specifically bind to AID (Activation-Induced cytidine
Deaminase) proteins, compositions comprising said antibodies, and cells
producing said antibodies, are described. The AID proteins are
structurally related to APOBEC-1,l an RNA editing enzyme, and have a
cytidine deaminase activity similar to APOBEC-1. The AID genes were found
by preparing cDNA libraries from mouse B cell clone CH12F3-2 (which
undergoes class switch recombination from IgM to IgA at an extremely high
rate after activation of the cells by stimulation with cytokines), with
and without stimulation with cytokines, and performing subtraction
cloning using the libraries.