MPO and Autoimmunity: To assess the effect of exogenous rhDNase I on the development of anti-MPO autoimmunity, DNase I or vehicle control was administered to C57BL/6J WT mice (n = 10 each group) 1 day prior to the groups receiving subcutaneous immunization with rmMPO in FCA, followed by daily injections of saline or rhDNase I for a further 10 days (Figure 5A).