title: Selective depletion of nonspecific T cells during the early stage of immune responses to infection.
abstract: Transient T cell depletion occurs before the development of an effective immune response to infection. In this study we show that most T cells, regardless of specificity, are induced to express early activation markers soon after infection with Listeria monocytogenes or lymphocytic choriomeningitis virus. Ag-specific T cells are further activated to display late activation markers and undergo extensive proliferation. As Ag-specific T cells begin to expand, nonspecific T cells are depleted en masse and exhibit no sign of further activation or proliferation before their depletion. This selective depletion of nonspecific T cells is due to in situ death via apoptosis, as visualized by confocal microscopy. Thus, early activation and subsequent depletion of nonspecific T cells are integral parts of the immune response to proinflammatory infections. These results have important implications for our understanding of early events in the development of a robust T cell response.
authors.affiliation: Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6076, USA.
authors.forename: Jiu
authors.initials: J
authors.lastname: Jiang
authors.forename: Lisa L
authors.initials: LL
authors.lastname: Lau
authors.forename: Hao
authors.initials: H
authors.lastname: Shen
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000276:immunology; D002455:Cell Division / Q000276:immunology; D007399:Interphase / Q000276:immunology; D008088:Listeriosis / Q000276:immunology* / Q000473:pathology; D008213:Lymphocyte Activation; D008216:Lymphocytic Choriomeningitis / Q000276:immunology / Q000473:pathology; D008231:Lymphopenia / Q000276:immunology* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000382:microbiology / Q000473:pathology / Q000821:virology