Presentation Information
[C14-01]Information and Control Theory Reveal Constraints on Immune Signaling Architecture
*Yutaro Kumagai1 (1. The National Institute of Advanced Industrial Science and Technology (Japan))
Keywords:
immune system,repertoire,mutual information,control theory
The immune system is traditionally understood as a mechanism that distinguishes and protects self from non-self. However, this distinction is not always straightforward, leading to difficulties in defining the immune system's operational principles and objective function, and thus in modeling the system. By examining a range of immune systems, from the acquired immunity of humans to the lamprey's distinct molecular systems, we identified the generation of cells with diverse specificities, which respond and adapt through proliferation and differentiation/activation, as an evolutionarily common strategy.
This observation led us to hypothesize that the immune system compresses high-dimensional environmental data into lower-dimensional information, specifically, the distribution of immune cell repertoires, and then uses it to modulate the environment. We propose that the immune system’s primary goal is to maximize the information between itself and its environment to achieve control over the environment, while minimizing the cost of immune activation.
By modeling the system as a process of maximizing mutual information through adjusting cell repertoires, our research suggests that the immune system achieves global optimization via cell population dynamics controlled by specific intracellular signaling. While experimental evidence from T cell receptor signaling supports the pivotal role of the signaling structure in optimizing individual T cell responses, our work extends this perspective by showing that these signaling mechanisms are crucial not only for individual cell function but also for the global information processing of the immune system. Furthermore, by modeling the system as a control process, with harm to self treated as a cost function, we demonstrate that particular immune cell–cell interaction structures are necessary to achieve optimal control.
We also show that this global optimization can be realized through cell migration, proliferation, and death, interpreted as a constrained optimization process via gradient descent. These findings, where a small number of information-theoretic and control-theoretic principles can explain well-known immune cell interactions and intracellular signaling, will open new avenues for modeling the immune system.
This observation led us to hypothesize that the immune system compresses high-dimensional environmental data into lower-dimensional information, specifically, the distribution of immune cell repertoires, and then uses it to modulate the environment. We propose that the immune system’s primary goal is to maximize the information between itself and its environment to achieve control over the environment, while minimizing the cost of immune activation.
By modeling the system as a process of maximizing mutual information through adjusting cell repertoires, our research suggests that the immune system achieves global optimization via cell population dynamics controlled by specific intracellular signaling. While experimental evidence from T cell receptor signaling supports the pivotal role of the signaling structure in optimizing individual T cell responses, our work extends this perspective by showing that these signaling mechanisms are crucial not only for individual cell function but also for the global information processing of the immune system. Furthermore, by modeling the system as a control process, with harm to self treated as a cost function, we demonstrate that particular immune cell–cell interaction structures are necessary to achieve optimal control.
We also show that this global optimization can be realized through cell migration, proliferation, and death, interpreted as a constrained optimization process via gradient descent. These findings, where a small number of information-theoretic and control-theoretic principles can explain well-known immune cell interactions and intracellular signaling, will open new avenues for modeling the immune system.