How Does Cross-Reactive Stimulation Affect the Longevity of CD8+ T Cell Memory?

• Type of Material: Article
• Authors: Vitaly V Ganusov, Emory University; Sergei S Pilyugin, University of Florida; Rafi Ahmed, Emory University; Rustom Antia, Emory University
• Language: English
• Date: 2006-06
• Publisher: Public Library of Science
• Publication Version: Final Published Version
• Copyright Statement: © 2006 Ganusov et al.
• License: Creative Commons Attribution 3.0 Unported
• Final Published Version (URL): http://www.ploscompbiol.org/article/info%3Adoi%2F10.1371%2Fjournal.pcbi.0020055
• Title of Journal or Parent Work: PLoS Computational Biology
• ISSN: 1553-734X
• Volume: 2
• Issue: 6
• Start Page: e55
• End Page: e55
• Grant/Funding Information: This work was supported by NIH grant AI 49334 to Rustom Antia.
• Research Categories: Biology, General; Biology, Microbiology; Health Sciences, Immunology

Abstract

Immunological memory—the ability to “remember” previously encountered pathogens and respond faster upon re-exposure is a central feature of the immune response in vertebrates. The cross-reactive stimulation hypothesis for the maintenance of memory proposes that memory cells specific for a given pathogen are maintained by cross-reactive stimulation following infections with other (unrelated) pathogens. We use mathematical models to examine the cross-reactive stimulation hypothesis. We find that: (i) the direct boosting of cross-reactive lineages only provides a very small increase in the average longevity of immunological memory; (ii) the expansion of cross-reactive lineages can indirectly increase the longevity of memory by reducing the magnitude of expansion of new naive lineages which occupy space in the memory compartment and are responsible for the decline in memory; (iii) cross-reactive stimulation results in variation in the rates of decline of different lineages of memory cells and enrichment of memory cell population for cells that are cross-reactive for the pathogens to which the individual has been exposed.