Long-term prevention of diabetes and marked suppression of insulin autoantibodies and insulitis in mice lacking native insulin B9-23 sequence.
We analyzed double native insulin gene knockout NOD mice with a mutated (B16:alanine) proinsulin transgene at multiple ages for the development of insulin autoantibodies, insulitis, and diabetes. In contrast to mice with at least one copy of a native insulin gene that expressed insulin antibodies, only 2 out of 21 (10%) double native insulin gene knockout mice with a mutated insulin transgene developed insulin autoantibodies. Of 21 double insulin knockout mice sacrificed between 10 to 48 weeks of age, only 5 showed minimal insulitis versus 100% of wild-type NOD and more than 90% of insulin 1 knockout mice. Consistent with robust suppression of insulin autoantibodies and insulitis, no double insulin knockout mice developed diabetes. In that the B9-23 peptide with B16A is an altered peptide ligand inducing Th2 responses, we analyzed transfer of splenocytes into NOD.SCID mice. There was no evidence for regulatory T cells able to inhibit transfer of diabetes by diabetogenic NOD splenocytes. Insulin peptide B9-23 is likely a crucial target for initiation of islet autoimmunity and further mutation of the sequence will be tested to attempt to eliminate all anti-islet autoimmunity.
Nakayama
M
M
Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, P.O. Box 6511, Aurora, CO 80045, USA.
Babaya
N
N
Miao
D
D
Gianani
R
R
Liu
E
E
Elliott
J F
JF
Eisenbarth
G S
GS
D000409:Alanine / Q000378:metabolism; D019943:Amino Acid Substitution; D000818:Animals; D001323:Autoantibodies / Q000032:analysis*; D017690:Cell Transplantation; D003922:Diabetes Mellitus, Type 1 / Q000209:etiology / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000517:prevention & control*; D007330:Insulin Antibodies / Q000032:analysis* / Q000276:immunology; D007515:Islets of Langerhans / Q000473:pathology; D051379:Mice; D016688:Mice, Inbred NOD; D018345:Mice, Knockout; D016513:Mice, SCID; D011384:Proinsulin / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology; D019076:Transgenes
D001323:Autoantibodies; D007330:Insulin Antibodies; D011384:Proinsulin; D000409:Alanine