title: Cutting edge: Asymmetric memory T cell division in response to rechallenge.
abstract: Clonal selection of a T cell for use in the immune response appears to necessitate proliferative expansion and terminal effector differentiation of some cellular progeny, while reserving other progeny as less-differentiated memory cells. It has been suggested that asymmetric cell division may promote initial cell diversification. Stem cell-like models of adaptive immunity might predict that subsequent encounters with a pathogen would evoke reiterative, self-renewing, asymmetric division by memory T cells. In this study, we show that murine memory CD8(+) T cells can divide asymmetrically in response to secondary encounter with pathogen. Critical regulators of signaling and transcription are partitioned to one side of the mitotic spindle in rechallenged memory T cells, and two phenotypically distinct populations of daughter cells are evident from the earliest divisions. Memory T cells may thus use asymmetric cell division to generate cellular heterogeneity when faced with pathogen rechallenge.
authors.affiliation: Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Maria L
authors.initials: ML
authors.lastname: Ciocca
authors.forename: Burton E
authors.initials: BE
authors.lastname: Barnett
authors.forename: Janis K
authors.initials: JK
authors.lastname: Burkhardt
authors.forename: John T
authors.initials: JT
authors.lastname: Chang
authors.forename: Steven L
authors.initials: SL
authors.lastname: Reiner
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002455:Cell Division / Q000235:genetics / Q000276:immunology*; D007156:Immunologic Memory; D008216:Lymphocytic Choriomeningitis / Q000235:genetics / Q000276:immunology*; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology*; D051379:Mice; D008822:Mice, Transgenic; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology*; D014158:Transcription, Genetic / Q000235:genetics / Q000276:immunology