The expression of insulin-like growth factors and their binding proteins in normal human lymphocytes.
The expression of insulin-like growth factors and their binding proteins in normal human peripheral lymphocytes was studied using the reverse transcriptase polymerase chain reaction method and Western ligand blotting. A quantitation of RT-PCR products was used to study the differences between normal and PHA stimulated lymphocytes. Normal freshly collected lymphocytes expressed mRNAs for both IGF-I receptor and IGF-II receptor but no expression of the corresponding growth factors was detectable. After stimulation with phytohemagglutinin the lymphocytes, however, expressed both IGF-I and IGF-II. Of the five IGFBPs examined, unstimulated lymphocytes expressed only IGFBP-2 and -3. Stimulated lymphocytes expressed IGFBP-4 and -5, in addition to IGFBP-2 and -3, whereas IGFBP-1 mRNA remained undetectable. The ligand blotting of lymphocyte conditioned media revealed production of 34K, 43K and 49K IGFBPs. The addition of estrogen, progesterone, IGF-I or growth hormone did not affect secretion of IGFBPs by lymphocytes.
Nyman
T
T
Minerva Institute for Medical Research, Medix Research Unit, Helsinki, Finland.
Pekonen
F
F
D015139:Blotting, Southern; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics*; D015870:Gene Expression; D006728:Hormones / Q000494:pharmacology; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D010835:Phytohemagglutinins / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis*; D012194:RNA-Directed DNA Polymerase; D013002:Somatomedins / Q000235:genetics*
D002352:Carrier Proteins; D006728:Hormones; D018969:Insulin-Like Growth Factor Binding Proteins; D010835:Phytohemagglutinins; D012333:RNA, Messenger; D013002:Somatomedins; D012194:RNA-Directed DNA Polymerase