Memory T cell inflation: understanding cause and effect.
Typically, during viral infections, T cells encounter antigen, undergo proliferative expansion and ultimately contract into a pool of memory cells. However, after infection with cytomegalovirus, a ubiquitous β-herpesvirus, T cell populations specific for certain epitopes do not contract but instead are maintained and/or accumulate at high frequencies with a characteristic effector-memory phenotype. This feature has also been noted after other infections, for example, by parvoviruses. We discuss this so-called memory T cell inflation and the factors involved in this phenomenon. Also, we consider the potential therapeutic use of memory T cell inflation as a vaccine strategy and the associated implications for immune senescence.
Peter Medawar Building for Pathogen Research, South Parks Road, Oxford OX1 4SY, UK. geraldine.ohara@ndm.ox.ac.uk
Geraldine A
GA
O'Hara
Suzanne P M
SP
Welten
Paul
P
Klenerman
Ramon
R
Arens
D000818:Animals; D003586:Cytomegalovirus Infections / Q000276:immunology / Q000821:virology; D006801:Humans; D007156:Immunologic Memory; D010641:Phenotype; D013601:T-Lymphocytes / Q000276:immunology* / Q000821:virology; D014611:Vaccination