Soybean trypsin inhibitor. An IL-1-like protein?
Soybean trypsin inhibitor (SBTI) shares some structural homology with interleukin-1 (IL-1) and was tested for IL-1 bioactivity. Human T-cells proliferated maximally when stimulated with PMA and SBTI but failed to respond to either stimulus alone. This response was abrogated by neutralizing antibodies to IL-1 beta but not to IL-1 alpha. However, immunoblots showed no cross-reactivity between SBTI and anti-IL-1 antibodies. Furthermore, SBTI did not bind to IL-1 receptors on YT cells and did not activate a murine T-lymphoma or human T-hybridoma. Supernantants from monocytes stimulated with SBTI contained significant levels of IL-1 activity. The data show that SBTI has no direct IL-1 activity but can stimulate T-cells indirectly through an IL-1 dependent mechanism.
Richard
K A
KA
Department of Hypersensitivity Diseases, Upjohn Company, Kalamazoo, MI 49001.
Speziale
S C
SC
Staite
N D
ND
Berger
A E
AE
Deibel
M R
MR
Finzel
B C
BC
Einspahr
H M
HM
D006801:Humans; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000032:analysis* / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects*; D013601:T-Lymphocytes / Q000187:drug effects*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014360:Trypsin Inhibitor, Kunitz Soybean / Q000032:analysis* / Q000494:pharmacology; D014361:Trypsin Inhibitors / Q000032:analysis*
D007375:Interleukin-1; D014361:Trypsin Inhibitors; D014360:Trypsin Inhibitor, Kunitz Soybean; D013755:Tetradecanoylphorbol Acetate