Theoretical analysis of the evolution of immune memory
Authored by Frederik Graw, Carsten Magnus, Roland R Regoes
Date Published: 2010
DOI: 10.1186/1471-2148-10-380
Sponsors:
Swiss National Science Foundation (SNSF)
Platforms:
C++
Model Documentation:
Other Narrative
Model Code URLs:
Model code not found
Abstract
Background: The ability of an immune system to remember pathogens
improves the chance of the host to survive a second exposure to the same
pathogen. This immunological memory has evolved in response to the
pathogen environment of the hosts. In vertebrates, the memory of
previous infection is physiologically accomplished by the development of
memory T and B cells. Many questions concerning the generation and
maintenance of immunological memory are still debated. Is there a limit
to how many memory cells a host can generate and maintain? If there is a
limit, how should new cells be incorporated into a filled memory
compartment? And how many different pathogens should the immune system
remember?
Results: In this study, we examine how memory traits evolve as a
response to different pathogen environments using an individual-based
model. We find that even without a cost related to the maintenance of a
memory pool, the positive effect of bigger memory pool sizes saturates.
The optimal diversity of a limited memory pool is determined by the
probability of re-infection, rather than by the prevalence of a pathogen
in the environment, or the frequency of exposure.
Conclusions: Relating immune memory traits to the pathogen environment
of the hosts, our population biological framework sheds light on the
evolutionary determinants of immune memory.
Tags
Competition
differentiation
Infections
Effector
Responses
Homeostasis
Antigen
Cd8 t-cells
Immunological memory
Attrition