Immunecomplex-degradation ability ofmacrophages inMRL/Mp-lpr/lpr lupusmiceanditsregulation bycytokines

intodisease-bearing MRL/lprmice, degradation oftheseelectrondense bodies inthemacrophages inglomeruli was noted. We developed aquantitative invitro assay forICdegradation activity ofMRL/lprresident peritoneal macrophages (RPM)using peroxidaselabelled ICderived fromMRL/lpr mouse sera.Theability oftheRPM todegrade ICwas remarkably enhanced bythepretreatment withHUT102cellproducts andtherelated humanrecombinant cytokines, lymphotoxin andIL-lh. Moreover, pretreatment ofRPM fromnon-diseased MRL/Mp+/+ micewiththeculture supernatant ofspleen cells fromdiseased MRL/lpr micereduced their IC degradation activity. Theseresults suggested thattheability ofmacrophages todegrade ICinMRL/ Mpstrains ofmiceisunder theregulation ofcytokines, andtheimpaired ability inthedisease-bearing micemay betheresult ofabnormalities inthecytokine systeminthese mice.