Coexpression of the genes for platelet-derived growth factor and its receptor in human T-cell lines infected with HTLV-I.
Several HTLV-I-infected T-cell lines express the two genes encoding platelet-derived growth factor (PDGF). Therefore, we examined the question of a possible self-stimulatory mechanism of proliferation involving PDGF in these cells. Using a nucleic acid probe and an antibody specific for the PDGF-B receptor (PDGFR-B), we examined four established human T-cell lines infected with HTLV-I, as well as several noninfected T-cell lines for expression of the PDGF-B receptor. Previous reports indicate that lymphocytes do not display receptors for PDGF; our results show that two noninfected T-cell lines (HUT-78, CCRF-HSB-2) expressed the canonical 5.5-kb PDGFR mRNA, and two HTLV-I-infected T-cell lines (C10/MJ, MT-2) expressed a novel PDGFR mRNA of 4.8 kb. Concomitantly, the cell lines expressing PDGFR mRNA also synthesize PDGFR proteins immunoprecipitated by the antibody to PDGFR-B. Differences were observed in the molecular weight of PDGFR molecules immunoprecipitated from uninfected and HTLV-infected T-cells. Immunofluorescence studies demonstrated that the PDGFR-B proteins are localized primarily on the cell external membrane. The results suggest that the HTLV-I-infected T-cells acquire an autostimulatory mechanism of cell proliferation that involves PDGF.
Goustin
A S
AS
Center for Blood Research, Boston, Massachusetts 02115.
Galanopoulos
T
T
Kalyanaraman
V S
VS
Pantazis
P
P
D002461:Cell Line, Transformed; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D015368:Human T-lymphotropic virus 1; D006801:Humans; D010982:Platelet-Derived Growth Factor / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000378:metabolism; D017479:Receptors, Platelet-Derived Growth Factor; D013601:T-Lymphocytes / Q000378:metabolism*; D014158:Transcription, Genetic
D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D017479:Receptors, Platelet-Derived Growth Factor