Interleukin 2 exerts autocrine stimulation on murine T-cell leukaemia growth.
As it has been suggested that an autocrine mechanism may control tumour cell growth, in this work cells from a spontaneous murine T lymphocyte leukaemia (LB) expressing the interleukin-2 receptor (IL-2R) (CD25) were evaluated in vitro for IL-2-mediated autocrine growth. Cells grew readily in culture and proliferation was enhanced by the addition of recombinant IL-2 but inhibited by monoclonal antibodies against either IL-2 or IL-2 receptor, in the absence of exogenous IL-2. Cyclosporin A also inhibited LB cell growth. However, when exogenous IL-2 was added together with cyclosporin A, cell proliferation proved similar to controls. Using reverse transcription polymerase chain reaction (PCR), mRNA for IL-2 was found to be present in tumour cells. Our findings support the hypothesis that LB tumour cell proliferation is mediated by an autocrine pathway involving endogenous IL-2 generation, despite the fact that these cells are not dependent on exogenous IL-2 to grow in culture.
Waldner
C I
CI
Cátedra de Immunologia, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, IDEHU, Argentina.
Mongini
C
C
Alvarez
E
E
Sánchez Lockhart
M
M
Gravisaco
M J
MJ
Hajos
S E
SE
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D016572:Cyclosporine / Q000494:pharmacology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007376:Interleukin-2 / Q000502:physiology*; D015458:Leukemia, T-Cell / Q000473:pathology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D015375:Receptors, Interleukin-2 / Q000502:physiology
D007166:Immunosuppressive Agents; D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D016572:Cyclosporine