A Specific Inhibitor for Human Desoxyribonuclease and an Inhibitor of the Lupus Erythematosus Cell Phenomenon From Leucocytes 1

In speculating upon the probable role of desoxy- ribonuclease (DNase) in the depolymerization of desoxyribonucleic acid (DNA), which character- izes (1) the "lupus erythematosus (L.E.) cell" (2), we have suggested (3), as have Klemperer and his associates (4), that an increased serum en- zyme activity, potentiation of an intracellular DNase, or destruction of an intracellular inhibitor of DNase by a serum factor, might be responsible. In a previous communication (5) we reported evi- dence which excludes the serum DNase from re- sponsibility for the phenomenon. Studies on the interaction of leucocytes and serum, in an ap- proach to the alternative possibilities, disclosed the presence of a specific intracellular inhibitor of hu- man serum DNase and an inhibitor of the "L.E.