471-P: Anti-NFKB Inhibitor Beta Antibody Correlates with Cardiovascular Disease in Type 1 Diabetic Patients with Autoimmune Disease

Cardiovascular disease (CVD) is a major cause of mortality in Type 1 diabetes (T1D). Studies suggest that autoimmunity may influence CVD development in T1D. We created a novel T1D-CVD mouse model by deleting ApoE via CRISPR/Cas9 editing in nonobese diabetic (ApoE^-/-/NOD) mice, an autoimmune T1D model, and observed that both diabetic and nondiabetic ApoE-/-/NOD mice showed autoimmune insulitis and greater atherosclerotic lipid deposition and plaque formation compared to CongApoE-/‘- wild type (WT) mice. Plasma studies with autoantigen proteomic microarray from people with long-duration T1D>50 years (“Medalists”), identified potential autoantibodies (AAb) targeting antigens in aortic plaques, which correlated to coronary artery calcium (CAC). One protein, nuclear factor-KB inhibitor beta (NFKBIB, p=0.0017), was higher in plasma of Medalists positive for HLA T1D risk alleles (HLA+) compared to HLA(-) Medalists. To quantify circulating anti-NFKBIB in Medalist samples, we developed an immunoassay using novel electrochemiluminescence technology. Our findings showed higher anti-NFKBIB AAb in HLA(+) versus HLA(-) Medalists. Moreover, in the HLA(+) group, higher anti-NFKBIB AAb was seen in those with CVD. To corroborate these findings from Medalist patients, we analyzed plasma from ApoE^-/-/NOD mice with autoimmune T1D, as well as control nondiabetic CongApoE/NOD mice. Immunoblot analysis showed that only isolated IgG from plasma of ApoE^-/-/NOD mice detected NFKBIB in aortic lysates and/or purified recombinant NFKBIB protein in a concentration-dependent manner, relative to IgG from control mice. Flow cytometry analysis of immunocytes revealed twofold increases in blood and para-aortic B- (CD19+, p=0.012) and T-cell (CD4+, p=0.008) populations of ApoE^-/-/NOD mice compared to WT mice. These suggest that anti-NFKBIB AAb is a novel AAb present in people and mouse models with T1D and atherosclerosis, and may contribute to CVD development in T1D.