Introduction

1. Introduction • Anti-CD3 monoclonal Ab has been used successfully to revert diabetes in NOD mice, a murine model for Type I diabetes. Some laboratories are able to show up to an 80% correction of the hyperglycemia, while in our lab and other labs we are only able to show 40-50% correction rate. • In humans, when anti-CD3 mAb is administered within 6 weeks of diagnosis of Type I DM, it decreases HbA1c and insulin requirement, but does not revert the diabetes. • Exendin-4 is an analogue of GLP-1 which has been shown to increase neogenesis of beta cells and increase beta cell mass.

2. Anti-CD3 mAb and Exendin-4 in reversal of Type I DM in NOD mice Mariela Glandt Principal Investigator: Kevan Herold Columbia University

3. Aims • To see if we can increase the percentage of mice that are euglycemic after treatment by combining antiCD3 mAb with exendin-4. • To see if beta cell mass is higher when mice are treated with anti-CD3mAb and exendin-4 vs anti-CD3 alone • To see if glucose levels are lower in mice treated with both anti-CD3 mAb and exendin-4, as compared to anti-CD3 alone

4. Methods • NOD mice were monitored 3 times a week by urine dipstick until glucose was noted in urine. Glucose was then measured by tail venous sampling. • When glucose was >200, they were treated with either anti-CD3 mAb only, anti-CD3mAb+ exendin-4, insulin only, or exendin-4 only. • The mice’s sugars were followed biweekly by tail vein sampling. • The mice underwent glucose tolerance test and were subsequently sacrificed at 3 weeks, 8 weeks, or 25 weeks • The pancreases were fixed and stained for insulin and Ki67 • Beta cell mass and replication rates were obtained by analysis using Image Pro software

5. Results • 55 mice were treated with anti-CD3 mAb 29 mice were treated with anti-CD3 mAb + exendin-4 10 mice were treated with insulin only 4 mice were treated with exendin-4 only • Glucose levels at start of treatment were similar in all 4 gps • 45% of mice treated with anti-CD3 mAb reverted to euglycemia 72.4% of mice treated with anti-CD3 mAb and exendin-4 reverted to euglycemia none of the mice treated with insulin or exendin-4 alone reverted to euglycemia • beta cell mass and neogenesis calculations are still under way

6. Success in reverting overt diabetes in NOD mice P=0.0222

7. Conclusions • In NOD mice that have developed overt diabetes, treatment with anti-CD3 mAb and anti-CD3 mAb combined with exendin-4 results in reverting the disease. • The success rate is higher when using anti-CD3 mAb with exendin-4, as opposed to using anti-CD3 mAb by itself. • Analysis of beta cell mass, replication rates, and neogenesis is still under way to compare between the two groups