title: Diversity of immune strategies explained by adaptation to pathogen statistics.
abstract: Biological organisms have evolved a wide range of immune mechanisms to defend themselves against pathogens. Beyond molecular details, these mechanisms differ in how protection is acquired, processed, and passed on to subsequent generations-differences that may be essential to long-term survival. Here, we introduce a mathematical framework to compare the long-term adaptation of populations as a function of the pathogen dynamics that they experience and of the immune strategy that they adopt. We find that the two key determinants of an optimal immune strategy are the frequency and the characteristic timescale of the pathogens. Depending on these two parameters, our framework identifies distinct modes of immunity, including adaptive, innate, bet-hedging, and CRISPR-like immunities, which recapitulate the diversity of natural immune systems.
authors.affiliation: Laboratoire de Physique Théorique, CNRS, Université Pierre et Marie Curie, and École Normale Supérieure, 75005 Paris, France;
authors.forename: Andreas
authors.initials: A
authors.lastname: Mayer
authors.affiliation: Laboratoire de Physique Statistique, CNRS, Université Pierre et Marie Curie, and École Normale Supérieure, 75005 Paris, France; tmora@lps.ens.fr.
authors.forename: Thierry
authors.initials: T
authors.lastname: Mora
authors.affiliation: Laboratoire Interdisciplinaire de Physique, CNRS and Université Grenoble Alpes, 38000 Grenoble, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Rivoire
authors.affiliation: Laboratoire de Physique Théorique, CNRS, Université Pierre et Marie Curie, and École Normale Supérieure, 75005 Paris, France;
authors.forename: Aleksandra M
authors.initials: AM
authors.lastname: Walczak
mesh_terms: D000222:Adaptation, Physiological / Q000276:immunology*; D056704:Adaptive Immunity / Q000276:immunology*; D000465:Algorithms; D000818:Animals; D005075:Biological Evolution; D003198:Computer Simulation; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology*; D018448:Models, Immunological
keywords: CRISPR immunity; adaptive immunity; bet hedging; evolution of immunity; immune systems