Immuno-suppressive effect of blocking the CD28 signaling pathway in T-cells by an active component of Echinacea found by a novel pharmaceutical screening method.
AFTIR (after flowing through immobilized receptor) is a novel method for screening herbal extracts for pharmaceutical properties. Using AFTIR, we identified Cynarin in Echinacea purpurea by its selective binding to chip immobilized CD28, a receptor of T-cells, which is instrumental to immune functioning. The results of surface plasma resonance show that binding between immobilized CD28 and Cynarin is stronger than the binding between CD28 and CD80, a co-stimulated receptor of antigen presenting cells. Cynarin's function was verified by its ability to downregulate CD28-dependent interleukin-2 (IL-2) expression in a T-cell culture line. AFTIR offers promise as an efficient screening method for herbal medicines.
Institute of BioAgricultural Sciences, Academia Sinica, Taipei, Taiwan 115, Republic of China.
Guo-Chung
GC
Dong
Ping-Hsien
PH
Chuang
Michael D
MD
Forrest
Yi-Chen
YC
Lin
Hueih Min
HM
Chen
D000818:Animals; D018122:B7-1 Antigen / Q000737:chemistry; D018106:CD28 Antigens / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D002851:Chromatography, High Pressure Liquid; D002934:Cinnamates / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D020900:Echinacea / Q000737:chemistry*; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000235:genetics; D007074:Immunoglobulin G / Q000235:genetics; D007166:Immunosuppressive Agents / Q000737:chemistry / Q000494:pharmacology*; D007376:Interleukin-2 / Q000096:biosynthesis; D019169:Jurkat Cells; D051379:Mice; D010936:Plant Extracts / Q000737:chemistry; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D015398:Signal Transduction; D020349:Surface Plasmon Resonance; D013601:T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism
D018122:B7-1 Antigen; D018106:CD28 Antigens; D002934:Cinnamates; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D007166:Immunosuppressive Agents; D007376:Interleukin-2; D010936:Plant Extracts; D011993:Recombinant Fusion Proteins; C100257:cynarine