title: Dissecting the complexity of the memory T cell response.
abstract: Memory immune responses are classically attributed to the reactivation of long-lived, antigen-specific T lymphocytes that persist in a quiescent state. Determining mechanisms for the generation of memory T cells and dissecting the functional nature of the memory T cell pool has been encumbered by an inability to distinguish recently activated effector T cells from memory T cells. We have established new activation and biochemical criteria that distinguish effector and memory T cells and have applied these criteria to follow memory generation from activated cells in vivo. We found that the resultant memory T cell pool is heterogeneous and consists of effector-like and resting memory-like subsets that differ in expression of the homing receptor, CD62L. We discuss these findings in the context of memory T cell heterogeneity identified in human and mouse systems. These results suggest that more than one type of previously activated T cell can mediate recall or memory immune responses and that elucidating the fundamental phenotypic and functional features of memory T cell subsets is therefore critical to deciphering the complex nature of the memory immune response.
authors.affiliation: Department of Surgery, Division of Transplantation, University of Maryland Medical School, Baltimore 21201, USA. dfarber@smail.umaryland.edu
authors.forename: Donna L
authors.initials: DL
authors.lastname: Farber
authors.forename: Mojgan
authors.initials: M
authors.lastname: Ahmadzadeh
mesh_terms: D000818:Animals; D006801:Humans; D007156:Immunologic Memory; D019041:L-Selectin / Q000378:metabolism; D051379:Mice; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D019041:L-Selectin