title: Induction of bystander T cell proliferation by viruses and type I interferon in vivo.
abstract: T cell proliferation in vivo is presumed to reflect a T cell receptor (TCR)-mediated polyclonal response directed to various environmental antigens. However, the massive proliferation of T cells seen in viral infections is suggestive of a bystander reaction driven by cytokines instead of the TCR. In mice, T cell proliferation in viral infections preferentially affected the CD44hi subset of CD8+ cells and was mimicked by injection of polyinosinic-polycytidylic acid [poly(I:C)], an inducer of type I interferon (IFN I), and also by purified IFN I; such proliferation was not associated with up-regulation of CD69 or CD25 expression, which implies that TCR signaling was not involved. IFN I [poly(I:C)]-stimulated CD8+ cells survived for prolonged periods in vivo and displayed the same phenotype as did long-lived antigen-specific CD8+ cells. IFN I also potentiated the clonal expansion and survival of CD8+ cells responding to specific antigen. Production of IFN I may thus play an important role in the generation and maintenance of specific memory.
authors.affiliation: Department of Immunology, Scripps Research Institute, La Jolla, California 92037, USA.
authors.forename: D F
authors.initials: DF
authors.lastname: Tough
authors.forename: P
authors.initials: P
authors.lastname: Borrow
authors.forename: J
authors.initials: J
authors.lastname: Sprent
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002455:Cell Division; D002470:Cell Survival; D018960:Hyaluronan Receptors / Q000032:analysis; D007156:Immunologic Memory; D016130:Immunophenotyping; D007370:Interferon Type I / Q000276:immunology* / Q000494:pharmacology; D037181:Lectins, C-Type; D008213:Lymphocyte Activation; D008216:Lymphocytic Choriomeningitis / Q000276:immunology*; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D011070:Poly I-C / Q000494:pharmacology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D015375:Receptors, Interleukin-2 / Q000032:analysis; D000099192:CD69 Antigens
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D018960:Hyaluronan Receptors; D007370:Interferon Type I; D037181:Lectins, C-Type; D011070:Poly I-C; D011948:Receptors, Antigen, T-Cell; D015375:Receptors, Interleukin-2; D000099192:CD69 Antigens