TITLE:

MODELING TYPE 1 DIABETES IN NOD MICE (No. 123)

DATE:

Friday, September 15th, 2006

TIME:

3:30 PM

LOCATION:

GMCS 214

SPEAKER:

Joe Mahaffy, Department of Mathematics, San Diego State University

ABSTRACT:

Type 1 diabetes (T1D) is an autoimmune disease in which immune cells, notably T-lymphocytes target and kill the insulin-secreting pancreatic beta cells. Elevated blood sugar levels and full blown diabetes result once a large enough fraction of these beta cells have been destroyed. Recent investigation of T1D in animals (the non-obese diabetic (NOD) mice) has revealed large cyclic fluctuations in the levels of T cells circulating in the blood weeks before the onset of diabetes, but the mechanism for these oscillations is unclear. A mathematical model for the immune response suggests a possible explanation for the cyclic pattern of behaviour. We show that cycles similar to those observed experimentally can occur when activation of T cells is an increasing function of self-antigen level, whereas the production of memory cells declines with that level. Our model extends previous theoretical work on T cell dynamics in T1D, and leads to interesting nonlinear dynamics, including Hopf and homoclininc bifurcations in biologically reasonable regimes of parameters. This is work I accomplished while on sabbatical at the University of British Columbia with Professor Leah Keshet.

HOST:

Ricardo Carretero

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