Peptide and Major Histocompatibility Complex–Specific Breaking of Humoral Tolerance to Native Insulin With the B9-23 Peptide in Diabetes-Prone and Normal Mice

  1. Norio Abiru,
  2. Aristides K. Maniatis,
  3. Liping Yu,
  4. Dongmei Miao,
  5. Hiroaki Moriyama,
  6. Dale Wegmann and
  7. George S. Eisenbarth
  1. Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver, Colorado

    Abstract

    NOD mice spontaneously develop anti-insulin autoantibodies and diabetes. A dominant peptide recognized by T-cell clones from NOD mice is insulin B-chain peptide B9-23. When administered subcutaneously to NOD mice, this peptide decreases the development of diabetes. In this study, we evaluated the autoantibody response to native insulin after administration of the B9-23 peptide. In NOD mice, administration of the B9-23 peptide in incomplete Freund’s adjuvant enhanced their insulin autoantibody response with a higher level and longer persistence. Induction of insulin autoantibodies with the B9-23 peptide was observed in non–diabetes-prone BALB/c mice and NOR mice within 2 weeks of administration, but this was not observed in C57BL/6 mice. A series of A-chain, other B-chain, and proinsulin peptides did not induce insulin autoantibodies. Induced anti-insulin autoantibodies could not be absorbed with the peptide alone but could be absorbed with native insulin. The B13-23 peptide (one of two identified epitopes within B9-23) when administered to BALB/c mice, induced autoantibodies, whereas peptide B9-16 did not. Induction of autoantibodies mapped to the major histocompatibility complex (MHC) rather than to the background genes. Both splenocytes with I-Ad/I-Ed or I-Ag7/I-Enull presented the B9-23 peptide to NOD islet-derived T-cell clones. Finally, administration of the B9-23 peptide to BALB/c mice, even without adjuvant, could induce insulin autoantibodies. Our results indicate that B-cell tolerance to intact insulin is readily broken with the presentation of the B9-23 insulin peptide, depending on the host’s specific MHC.

    Footnotes

    • Address correspondence and reprint requests to George S. Eisenbarth, MD, PhD, Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, 4200 E. 9th Ave., Box B140, Denver, CO 80262. E-mail: george.eisenbarth{at}uchsc.edu.

      Received for publication 11 September 2000 and accepted in revised form 8 March 2001.

      APC, antigen-presenting cell; BSA, bovine serum albumin; IAA, insulin autoantibody; IFA, incomplete Freund’s adjuvant; MHC, major histocompatibility complex; TCR, T-cell receptor; TT, tetanus toxin.

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