title: Insulin-like growth factor-1 receptor regulation in activated human T lymphocytes.
abstract: OBJECTIVE
  To investigate the kinetics of insulin-like growth factor-1 receptor (IGF-1R) expression in PHA-stimulated T lymphocytes.
  
  
  METHODS
  IGF-1R protein and mRNA were detected by flow cytometry and RT-PCR respectively, between 0 and 48 h after cell activation.
  
  
  RESULTS
  Few minutes after T lymphocytes were activated, internalization of the IGF-1R from the cell membrane was observed, achieving the lower level between 1 and 6 h and was accompanied by a reduction in its mRNA. This was followed by re-expression of IGF-1R on the cell surface and an increase in IGF-1R mRNA levels in the cytoplasm, reaching levels higher than those recorded initially after 48 h activation.
  
  
  CONCLUSIONS
  This down- and up-regulation suggests that restoration of IGF-1R would be the result of receptor recycling and de novo synthesis and highlights its importance for T lymphocyte proliferation.
authors.affiliation: Instituto de Biología y Medicina Experimental CONICET, Buenos Aires, Argentina.
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Segretin
authors.forename: Adriana
authors.initials: A
authors.lastname: Galeano
authors.forename: Alicia
authors.initials: A
authors.lastname: Roldán
authors.forename: Roxana
authors.initials: R
authors.lastname: Schillaci
mesh_terms: D015536:Down-Regulation; D005434:Flow Cytometry; D006801:Humans; D007700:Kinetics; D008213:Lymphocyte Activation / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000378:metabolism / Q000502:physiology*; D015854:Up-Regulation
chemical_list: D012333:RNA, Messenger; D017526:Receptor, IGF Type 1