title: Memory-like CD8+ T cells generated during homeostatic proliferation defer to antigen-experienced memory cells.
abstract: Naive T cells proliferate in response to lymphopenia and acquire the phenotypic and functional qualities of memory T cells, providing enhanced protection against infection. How well memory-like T cells generated during lymphopenia-induced homeostatic proliferation (HP)-memory differentiate into secondary memory cells and compete with Ag-experienced true-memory cells is unknown. We found that CD8(+) HP-memory T cells generated robust responses upon infection and produced a secondary memory population comparable to true-memory cells in the absence of competition. However, when true-memory and HP-memory T cells competed during infection, HP-memory cells contributed less to the effector population, contracted earlier, and formed fewer secondary memory cells. Furthermore, HP- and true-memory cells demonstrated distinct chemokine receptor expression and localization within the spleen during infection, indicating differential access to signals necessary for secondary memory formation. Thus, HP-memory T cells provide protection without compromising the true-memory population. Differences in HP- and true-memory T cells may reveal the basis of competition for limited resources within the memory-T cell compartment.
authors.affiliation: University of California, San Diego, Division of Biological Sciences, La Jolla, CA 92093-0377, USA.
authors.forename: Kitty P
authors.initials: KP
authors.lastname: Cheung
authors.forename: Edward
authors.initials: E
authors.lastname: Yang
authors.forename: Ananda W
authors.initials: AW
authors.lastname: Goldrath
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology; D002465:Cell Movement / Q000276:immunology; D049109:Cell Proliferation; D006706:Homeostasis / Q000276:immunology*; D007156:Immunologic Memory; D008231:Lymphopenia / Q000276:immunology / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D015398:Signal Transduction / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte
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