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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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