Insulin-like growth factor-1 receptor regulation in activated human T lymphocytes.
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.
Segretin
María Eugenia
ME
Instituto de Biología y Medicina Experimental CONICET, Buenos Aires, Argentina.
Galeano
Adriana
A
Roldán
Alicia
A
Schillaci
Roxana
R
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
D012333:RNA, Messenger; D017526:Receptor, IGF Type 1