ZIH-Kolloquium: Using game theory to elucidate microbial and cancer pathogenesis

A useful methodology to study emergent properties in biology is Game Theory. It can be applied in the frequent situation where the fitness of a cell or organism does not only depend on its own properties (considered here as strategies) but also on those of other cell or organisms.  

In this talk, we will outline the fundamentals of Game Theory as applied in biology. Then we present two applications of game theoretical modeling. In host-pathogen interactions, hosts often produce a toxin and pathogens often produce an enzyme neutralizing the toxin. We conceptualize this as a defense and counter-defense. Our study reveals a paradox: If the inactivating enzyme is very efficient, the toxin becomes useless. If the toxin is no longer produced, the enzyme becomes useless, so that production of the toxin becomes useful again. Does this lead to an oscillatory change in strategies or instead to a steady state? Under certain conditions, we obtain ‘partial (counter-)defense’ strategies as stable equilibria in this game.

Several types of cancer cells are able to “decide” between staying at a primary site or to form metastases. To understand this so-called “go-or-grow” dichotomy better, we again use game theory. We start from a game-theoretical model proposed by Andreas Deutsch’s group. We determine the types of game, depending on parameter values, both for the basic model and for five modified variants that we suggested. We discuss our predictions in terms of the pros and cons of caloric restriction, limitation of the supply of vitamins or methionine.

Shalu Dwivedi got her Master of Science (M.Sc.) degree in Applied Mathematics from Indian Institute of Technology Roorkee (IITR), India and completed a one year research program in Industrial and Applied Mathematics (Fundamental Data Science) at Grenoble Alpes University, France. Since April 2021, she is pursuing her Ph.D. in Stefan Schuster’s lab in the Department of Bioinformatics, Friedrich Schiller University, Jena. She applies game theory and dynamical system modeling to analyze defense and counter-defense in host-pathogen interactions, and also metastasis in tumor cells.

Stefan Schuster earned a Diploma degree in biophysics in 1986 and a PhD degree in 1988, both at Humboldt University in Berlin under the supervision of Reinhart Heinrich. After being a postdoc in Berlin, Bordeaux and Amsterdam, he became a lecturer at Humboldt University in 1993 and a full professor in bioinformatics at the University of Jena in 2003. His main research interests are the modelling of metabolic networks, evolutionary game theory, biological oscillations and host-pathogen interactions.

ONLINE: Link ZIH-Colloquia