报告题目:Delay induced periodic solutions in a dendritic cell therapy model
报告时间:2024.06.01 08:30-11:30
报 告 人 :Prof.Yang Kuang Arizona State University
腾讯会议ID:160-982-706
Abstract:We formulate a tumor-immune interaction
model with a constant delay (time needed for a dendritic cell to become an
effector cell) to capture the behavior following application of a dendritic
cell therapy. The model is validated using experimental data from
melanoma-induced mice. Through theoretical and numerical analyses, the model is
shown to produce rich dynamics, such as a Hopf bifurcation and bistability. We
provide thresholds for tumor existence and, in a special case, tumor
elimination. Our work indicates a sensitivity in model outcomes to the immune
response time. We provide a stability analysis for the high tumor equilibrium.
For small delays in response, the tumor and immune system coexist at a low
level. Large delays give rise to fatally high tumor levels. Our computational
and theoretical work reveals that there exists an intermediate region of delay
that generates complex oscillatory, even chaotic, behavior. The model then
reflects uncertainty in treatment outcomes for varying initial tumor burdens,
as well as tumor dormancy followed by uncontrolled growth to a lethal size, a
phenomenon seen in vivo. Theoretical and computational analyses suggest
efficacious treatments to use in conjunction with the dendritic cell vaccine.
Analysis of a highly aggressive tumor confirms the importance of representation
with a time delay, as periodic solutions are generated when a delay is present.