Transferrin-like autocrine growth factor, derived from T-lymphoma cells, that inhibits normal T-cell proliferation.
Transferrin, the major iron-binding protein in the plasma of vertebrate species, is an essential growth factor for cells in serum free medium. We have established a cell line, Fr, from peripheral blood mononuclear cells of a patient affected by Sézary syndrome. Fr cells show a very immature antigenic phenotype, while constitutively bearing transferrin receptor on their surface. Furthermore the Fr line does not produce or respond to interleukin 2. Finally its conditioned medium contains both a growth stimulating activity for the Fr cell line and a factor which inhibits T-lymphocyte proliferation. We have identified a protein, produced in large amounts by Fr cells, which shares the immunological properties of human transferrin. Our data suggest that this transferrin-like factor can act as an autocrine growth factor for the producer cells and as an inhibitory factor for normal lymphocytes.
Morrone
G
G
Institute of Experimental and Clinical Oncology, Medical School, University of Reggio Calabria, Catanzaro, Italy.
Corbo
L
L
Turco
M C
MC
Pizzano
R
R
De Felice
M
M
Bridges
S
S
Venuta
S
S
D000954:Antigens, Surface / Q000032:analysis; D002455:Cell Division; D006133:Growth Substances / Q000032:analysis* / Q000494:pharmacology; D006801:Humans; D007166:Immunosuppressive Agents / Q000032:analysis; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects*; D008223:Lymphoma / Q000032:analysis* / Q000276:immunology; D010641:Phenotype; D013601:T-Lymphocytes / Q000187:drug effects*; D014168:Transferrin / Q000032:analysis* / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D000954:Antigens, Surface; D006133:Growth Substances; D007166:Immunosuppressive Agents; D007376:Interleukin-2; D014168:Transferrin