Immunology as a Metaphor for Computational ... - Napier University

Chapter 1. Introduction 3scientists are concerned however, the task essentially remains one of recognition followedby an action such as elimination, and it is the mechanisms by which the naturalimmune system achieves these aims that make the system so attractive to the topic ofinformation processing.1.2 Some Key Concepts and their Relevance to InformationProcessingThe immune system can be considered to be a remarkably efficient and powerful informationprocessing system which operates in a highly parallel and distributed manner.It operates in a dynamic and unpredictable environment in which it is necessaryto react to changes in a timely manner — this is achieved partly through imprecisebut efficient recognition mechanisms and by utilising memories of past experiencesto provide useful pointers to the correct course of action. It contains several featuresthat make it appealing from a computational point of view. These are summarisedbelow. The list attempts to correlate features of immune system with the well-knownterminology of information processing. The information is adapted from that given in[Dasgupta, 1998]:Recognition: The immune system can recognise and classify different patterns¢and generate selective responses. In the natural immune system, recognitionis achieved via inter-cellular binding, the strength of which is determined bymolecular shape and electrostatic charge. One view is that during the recognitionprocess, the immune system is solving the problem of self-nonself discrimination.Feature extraction: Features are extracted from pathogens by antigen presentingcells or APCs which extract features from them and present them on¢theirsurface. This serves two purposes, that of a filter and a lens. The filter removesnoise and the lens focuses attention.Diversity: The immune system can utilise a combinatoric process to generate¢a diverse set of pathogen recognising molecules, and ensures that at least some