The case for absolute ligand discrimination : modeling information processing and decision by immune T cells

TL;DR

This paper explores how immune T cells discriminate ligands based on quality rather than quantity, introducing adaptive sorting as a key mechanism, and analyzing its implementations, properties, and population-level decision dynamics.

Contribution

It models the process of absolute ligand discrimination in immune T cells, highlighting adaptive sorting and its implementations, and examines population-level decision effects.

Findings

Adaptive sorting effectively solves absolute discrimination.

Kinetic proofreading with negative feedback approximates adaptive sorting.

Population variability influences immune decision-making.

Abstract

Some cells have to take decision based on the quality of surroundings ligands, almost irrespective of their quantity, a problem we name "absolute discrimination". An example of absolute discrimination is recognition of not-self by immune T Cells. We show how the problem of absolute discrimination can be solved by a process called "adaptive sorting". We review several implementations of adaptive sorting, as well as its generic properties such as antagonism. We show how kinetic proofreading with negative feedback implements an approximate version of adaptive sorting in the immune context. Finally, we revisit the decision problem at the cell population level, showing how phenotypic variability and feedbacks between population and single cells are crucial for proper decision.