Characterization of a T cell-derived lymphokine that acts synergistically with IL 3 on the growth of murine mast cells and is identical with IL 4.
A mast cell-like cell line (SN-1) was established with the aid of growth factor(s) present in the supernatant of a Con A-stimulated L3T4+ T cell line. In analogy to other mast cell lines, IL 3 was identified as a growth factor for SN-1 cells. In addition, a second lymphokine produced by the T cells synergistically enhanced the IL 3-induced growth. This factor, originally termed mast cell growth enhancing factor (MaGEF), could be separated from IL 2, IL 3, and a CSF-like activity and was purified to homogeneity. The N-terminal amino acid sequence (8 residues) and the functional properties of this lymphokine proved to be identical with those reported for BSF-1 (IL 4). Unless applied at high concentrations, purified MaGEF did not stimulate growth of the SN-1 mast cells in the absence of IL 3. MaGEF was also found to act on two IL 2-dependent T cell lines by inducing significant thymidine incorporation which was suboptimal compared to that induced by IL 2 and which cannot be inhibited by anti-IL 2-antibodies. A panel of cell lines developed from mouse bone marrow with IL 3 or with a combination of IL 3 and MaGEF all reacted to MaGEF in the presence of IL 3 with considerably increased proliferation. It is therefore suggested that one of the physiological functions of MaGEF is to promote the recruitment of T-dependent mast cells.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D007377:Interleukin-3 / Q000494:pharmacology*; D015847:Interleukin-4; D007378:Interleukins / Q000096:biosynthesis*; D008407:Mast Cells / Q000276:immunology*; D051379:Mice; D008970:Molecular Weight; D011994:Recombinant Proteins / Q000276:immunology; D013601:T-Lymphocytes / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D007377:Interleukin-3; D007378:Interleukins; D011994:Recombinant Proteins; D015847:Interleukin-4