Early effects of insulin-like growth factor-1 in activated human T lymphocytes.
This study evaluates the effects of insulin-like growth factor (IGF)-1 receptor (IGF-1R) down-regulation in stimulated T lymphocytes by investigating the expression of early activation proteins CD69, CD25, and interleukin (IL)-2. We found that IGF-1 does not modify CD69 expression but increases transcription and protein synthesis of CD25 and IL-2. The lowest level of IGF-1R detected after 15 min of activation suggested that the effects of IGF-1 occur at the initiation of cell activation. The activation of IGF-1R was confirmed by IGF-1R phosphorylation and increased phosphorylation of microtubule-associated protein kinase. We also detected the alternative IGF-1 transcripts Ea, with paracrine/autocrine regulation, and Eb, with endocrine regulation, in Jurkat cells and in quiescent T lymphocytes, and we detected IGF-1 protein in the culture medium after stimulation. These data suggest that the proliferative effects of IGF-1 on T lymphocytes include both autocrine/paracrine and endocrine processes.
Brocardo
M G
MG
Instituto de Investigaciones Bioquímicas Fundación Campomar (IIB-UBA and IIBBA CONICET), Instituto de Biología y Medicina Experimental CONICET, and. Laboratorio de Patología Sanatorio Mater Dei, Buenos Aires, Argentina.
Schillaci
R
R
Galeano
A
A
Radrizzani
M
M
White
V
V
Guerrico
A G
AG
Santa-Coloma
T A
TA
Roldán
A
A
D015703:Antigens, CD / Q000187:drug effects / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000187:drug effects / Q000378:metabolism; D015536:Down-Regulation; D006801:Humans; D017874:Immediate-Early Proteins / Q000187:drug effects*; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000494:pharmacology*; D007376:Interleukin-2 / Q000378:metabolism; D019169:Jurkat Cells; D007700:Kinetics; D037181:Lectins, C-Type; D008213:Lymphocyte Activation; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000187:drug effects / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D014158:Transcription, Genetic / Q000187:drug effects; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D017874:Immediate-Early Proteins; D007334:Insulin-Like Growth Factor I; D007376:Interleukin-2; D037181:Lectins, C-Type; D020928:Mitogen-Activated Protein Kinases; D012333:RNA, Messenger; D017526:Receptor, IGF Type 1; D015375:Receptors, Interleukin-2; D000099192:CD69 Antigens