title: Tracking alloreactive cell division in vivo.
abstract: BACKGROUND
  The study of alloimmune responses has been limited by a lack of assays that can track the behavior of alloreactive lymphocytes in vivo. Here we utilize an experimental system that allows the identification and study of alloreactive CD4+ lymphocytes responding to major histocompatibility antigens in vivo.
  
  
  METHODS
  Responder mouse lymphocytes were labeled with a fluorescein-based dye, adoptively transferred into irradiated allogeneic stimulator mice, and recovered at serial time points for analysis by flow cytometry.
  
  
  RESULTS
  Discrete generations of CD4+ responder lymphocytes proliferating specifically in response to allogeneic MHC class II were distinguished by fluorescein intensity. Successive division of alloreactive CD4+ lymphocytes was traced up to six generations after 60 hr.
  
  
  CONCLUSIONS
  This experimental system provides information on the division kinetics of alloreactive CD4+ cells. Other applications include immunophenotyping of alloreactive lymphocyte subsets. Further study of systems such as this will allow the detailed characterization of how alloimmune responses are initiated and proceed in vivo.
authors.affiliation: Harrison Department of Surgical Research, University of Pennsylvania Medical Center, Philadelphia 19104, USA.
authors.forename: H K
authors.initials: HK
authors.lastname: Song
authors.forename: H
authors.initials: H
authors.lastname: Noorchashm
authors.forename: Y K
authors.initials: YK
authors.lastname: Lieu
authors.forename: S
authors.initials: S
authors.lastname: Rostami
authors.forename: S A
authors.initials: SA
authors.lastname: Greeley
authors.forename: C F
authors.initials: CF
authors.lastname: Barker
authors.forename: A
authors.initials: A
authors.lastname: Naji
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology*; D002455:Cell Division / Q000276:immunology; D018984:Epitopes, T-Lymphocyte; D005452:Fluoresceins; D005456:Fluorescent Dyes; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D007519:Isoantigens / Q000276:immunology; D007959:Lymphocyte Culture Test, Mixed / Q000379:methods; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D013388:Succinimides
chemical_list: C087165:5-(6)-carboxyfluorescein diacetate succinimidyl ester; D018984:Epitopes, T-Lymphocyte; D005452:Fluoresceins; D005456:Fluorescent Dyes; D000949:Histocompatibility Antigens Class II; D007519:Isoantigens; D013388:Succinimides