Cationic antigens as mediators of inflammation

Electrical charge is an important determinant of antigen deposition in tissue. Cationic antigens can bind to anionic sites found in many organs. The major focus of interest has been the renal glomerulus and the articular joint. Experimental models of immune complex glomerulonephritis and allergic arthritis were established with chemically cationized proteins. More recently the concept has been extended to natural cationic proteins and human disease. The histones were shown to be potent initiators of experimental immune complex nephritis and convincing evidence for their participation in both murine and human lupus nephritis was obtained. Evidence is also presented that cationic proteins from Borrelia burgdorferi and Yersinia enterocolitica may participate in the reactive arthritis associated with these bacteria. Eucaryotic and prokaryotic nucleic acid binding proteins were identified as prime candidates for causing both immune complex glomerulonephritis and antigen-induced allergic arthritis.