1. increasing incidence [+ 3-4%/year] • up to 50/105/year, earlier age at onset • multifactorial, polygenic disease • islet of Langerhans 1 autoantibody 2 autoantibodies • b cell 3 autoantibodies • islet cell autoantibodies • prediabetes Bottazzo & Doniach 1974, Lancet Kulmala et al. 1998, J Clin Invest TYPE 1 DIABETES MELLITUS • increasing incidence [+ 3-4%/year] • up to 50/105/year, earlier age at onset • multifactorial, polygenic disease anti-GAD anti-IA2 anti-insulin

2. MAIN ADVANCES 2003-2006 1- prediction autoantibodies genetic puzzle 2- proinsulin: the primary autoantigen 3- the importance of immune regulation 4- immunotherapy: the end of immunosuppression 5- the goal: b cell restoration + induction of immune tolerance 1- prediction autoantibodies genetic puzzle

3. STRATIFICATION OF RISK anti-IA2 & anti-insulin IgG2/IgG3/IgG4 anti-IA2b & IA2 multiepitopes anti-IA2 & anti-insulin autoantibody titers Achenbach et al, Diabetes, 2006

4. POSITIVITY THRESHOLD % individuals 0 50 90 95 97 99 autoantibody titer (percentiles) AUTOANTIBODY DETECTION: LIMITS  predictive positive value in atypical forms of type 1  delay to diabetes onset in prediabetes  other assays ?

5. T T CD3 CD3 CYTOKINES ANTIGEN RECOGNITION BY T CELLS T cell receptor MHC class II

6. Patient A2/A3 B18/B38 34-42 tetramet nb spots/106 cells 34-42 tetramet CD8 Pinske et al. PNAS, 2005 CD8+ T CELL RESPONSE [ELISPOT assay] Toma et al. PNAS, 2005

7. MAIN ADVANCES 2003-2006 1- prediction autoantibodies genetic puzzle 2- proinsulin: the primary autoantigen 3- the importance of immune regulation 4- immunotherapy: the end of immunosuppression 5- the goal: b cell restoration + induction of immune tolerance

8. ROLE OF PROINSULIN IN TYPE 1 DIABETES • PROINS 1-/-NOD MICE: • absence of diabetes PROINS 2-/-NOD MICE acceleration of diabetes  anti-insulin Abs ~ anti-GAD Abs ~ sialitis Ins1-/- Moriyama H et et al. Proc Natl Acad Sci USA 2003 Thebault-Baumont, Tardivel et al. 2003, 2005

9. AUTOANTIBODY IN OFFSPRING OF DIABETIC PARENTS anti-insulin autoantibodies Ziegler et al, Diabetes, 1999

10. MAIN ADVANCES 2003-2006 1- prediction autoantibodies genetic puzzle 2- proinsulin: the primary autoantigen 3- the importance of immune regulation 4- immunotherapy: the end of immunosuppression 5- the goal: b cell restoration + induction of immune tolerance

11. IMMUNE REGULATION IN TYPE 1 DIABETES EFFECTOR T CELL REGULATORY CELLS EFFECTOR T CELL REGULATORY CELLS T CD4+ CD25+ T CD4+ CD62L+ T CD8+ Th2 IL-4,5 Th3 IL-10 b CELL - Th3 TGFb T CD4+ Th1 cytokines T NK ISLET INFa TLRs

12. DETECTION IN HUMAN EXPANSION NOD • number ? • function ? protection Krukeja et al. 2002, J Clin Invest Tang Q et al. 2004, J Exp Med Kretschmer K et al. Nat Immunol 2005 Lindley S et al. 2005, Diabetes 10 2 small size CD25 FoxP3 GITR CTLA4 10 1 10 0 10 1 10 0 10 2 CD4 Shimon Sakaguchi 1995

13. MAIN ADVANCES 2003-2006 1- prediction autoantibodies genetic puzzle 2- proinsulin: the primary autoantigen 3- the importance of immune regulation 4- immunotherapy: the end of immunosuppression 5- the goal: b cell restoration + induction of immune tolerance

14. TREATMENT OF DIABETES WITH ANTI-CD3 months months months n = 40 (placebo) n = 40 (anti-CD3) Keymeulen B et al. 2005, N Engl J Med

15. MAIN ADVANCES 2003-2006 1- prediction autoantibodies genetic puzzle 2- proinsulin: the primary autoantigen 3- the importance of immune regulation 4- immunotherapy: the end of immunosuppression 5- the goal: b cell restoration + induction of immune tolerance

16. GENERATION OF NEW BETA CELLS • transdifferenciation from • ductal cells • acinar cells • hepatic precursor cells [through a dedifferenciation stage] differenciation from • embryonic adult stem cells • embryonic stem cells

17. DIFFERENCIATION OF b CELLS FROM ES CELLS pancreatic endoderm primitive gut tube insulin cells definitive endoderm posterior foregut D’Amour et al. Nat Biotechnol, 2006

18. DIFFERENCIATION OF b CELLS FROM ES CELLS C-PEPTIDE HUMAN ISLETS ESC-DERIVED CELLS D’Amour et al. 2006, Nart Biotech