title: Dynamic regulation of notch 1 and notch 2 surface expression during T cell development and activation revealed by novel monoclonal antibodies.
abstract: It is well established that Notch signaling plays a critical role at multiple stages of T cell development and activation. However, detailed analysis of the cellular and molecular events associated with Notch signaling in T cells is hampered by the lack of reagents that can unambiguously measure cell surface Notch receptor expression. Using novel rat mAbs directed against the extracellular domains of Notch1 and Notch2, we find that Notch1 is already highly expressed on common lymphoid precursors in the bone marrow and remains at high levels during intrathymic maturation of CD4(-)CD8(-) thymocytes. Notch1 is progressively down-regulated at the CD4(+)CD8(+) and mature CD4(+) or CD8(+) thymic stages and is expressed at low levels on peripheral T cells. Immunofluorescence staining of thymus cryosections further revealed a localization of Notch1(+)CD25(-) cells adjacent to the thymus capsule. Notch1 was up-regulated on peripheral T cells following activation in vitro with anti-CD3 mAbs or infection in vivo with lymphocytic chorio-meningitis virus or Leishmania major. In contrast to Notch1, Notch2 was expressed at intermediate levels on common lymphoid precursors and CD117(+) early intrathymic subsets, but disappeared completely at subsequent stages of T cell development. However, transient up-regulation of Notch2 was also observed on peripheral T cells following anti-CD3 stimulation. Collectively our novel mAbs reveal a dynamic regulation of Notch1 and Notch2 surface expression during T cell development and activation. Furthermore they provide an important resource for future analysis of Notch receptors in various tissues including the hematopoietic system.
authors.affiliation: Ludwig Institute for Cancer Research Ltd., Lausanne Branch, 1066 Epalinges, Switzerland.
authors.forename: Emma
authors.initials: E
authors.lastname: Fiorini
authors.forename: Estelle
authors.initials: E
authors.lastname: Merck
authors.forename: Anne
authors.initials: A
authors.lastname: Wilson
authors.forename: Isabel
authors.initials: I
authors.lastname: Ferrero
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.forename: Ute
authors.initials: U
authors.lastname: Koch
authors.forename: Floriane
authors.initials: F
authors.lastname: Auderset
authors.forename: Elisa
authors.initials: E
authors.lastname: Laurenti
authors.forename: Fabienne
authors.initials: F
authors.lastname: Tacchini-Cottier
authors.forename: Michel
authors.initials: M
authors.lastname: Pierres
authors.forename: Freddy
authors.initials: F
authors.lastname: Radtke
authors.forename: Sanjiv A
authors.initials: SA
authors.lastname: Luther
authors.forename: H Robson
authors.initials: HR
authors.lastname: Macdonald
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D002454:Cell Differentiation; D002462:Cell Membrane / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D051381:Rats; D051881:Receptor, Notch1 / Q000096:biosynthesis* / Q000276:immunology; D051883:Receptor, Notch2 / Q000096:biosynthesis* / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D013234:Stem Cells / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; C497763:Notch1 protein, rat; C497766:Notch2 protein, rat; D051881:Receptor, Notch1; D051883:Receptor, Notch2