PROTECTION FROM INSULIN-DEPENDENT DIABETES-MELLITUS AFFORDED BY INSULIN ANTIGENS IN INCOMPLETE FREUNDS-ADJUVANT DEPENDS ON ROUTE OF ADMINISTRATION

Several islet antigens have been shown to modify the time of onset and severity of spontaneous insulin dependent diabetes mellitus (IDDM) in NOD (non-obese diabetic) mice. Oral, intravenous and intra-nasal admi nistration of insulin and glutamic acid decarboxylase (GAD) or their d erived peptides have all been shown to be effective to differing degre es in reducing the incidence and delaying the onset of diabetes in thi s mouse model of the disease. Incomplete Freund's Adjuvant (IFA) has a lso played a key role in tolerance when co-administered with insulin p eptides subcutaneously. We show that route of administration may be of crucial importance, since although insulin B chain and the B9-23 pept ide given in IFA subcutaneously protected (either partially or complet ely) from IDDM, when given intraperitoneally they completely failed to modify the disease. (C) 1998 Academic Press Limited.