The effects of interleukins and other soluble factors on T-lymphocyte colony formation.
When plated in semi-solid media, PHA-stimulated human peripheral blood mononuclear cells (PBMC) form discrete T-cell colonies. By contrast, Sephadex G-10 non-adherent (NA) cells (greater than 96% T lymphocytes) show virtually no clonal growth unless cocultured with soluble factors derived from either normal adherent cells or tumour cell lines. Purified IL-1 was able to initiate colony growth of mitogen-stimulated NA cells; cultures containing 20 U of human IL-1 yielded colony counts that were only slightly less than those with PBMC. In addition, recombinant IL-2, free of measurable IL-1, was able to provide the initiating signal required for clonal expansion. Both recombinant and lymphocyte-derived IL-2 were able to enhance the clonal growth of PBMC. Colony growth could be initiated by supernatants derived from short-term cultures of either monocytic (U937, HL60) or B-cell (Raji, Daudi) tumour cell lines. The abilities of these tumour cell lines to promote clonal responses did not correlate with their contents of either IL-1 or IL-2. By contrast, supernatants derived from either K562 (an erythroleukaemic line) or MOLT 4 (a T-cell lymphoma) cells did not provide the initiating signal.
D000911:Antibodies, Monoclonal / Q000276:immunology; D002448:Cell Adhesion; D002460:Cell Line; D002999:Clone Cells; D003114:Colony-Forming Units Assay; D006801:Humans; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000276:immunology*; D007376:Interleukin-2 / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology; D008970:Molecular Weight; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D007375:Interleukin-1; D007376:Interleukin-2