title: IL-4 analogues with site-specific chemical modification at position 121 inhibit IL-4 and IL-13 biological activities.
abstract: IL-4 signaling into a cell occurs via assembly of a receptor complex that consists of a high-affinity IL-4Rα chain and a low affinity chain, where the low-affinity chain is either γc or IL-13Rα1. It has been previously shown that mutational disruption of the low affinity interface in the IL-4DM (double mutein) yields an antagonist that inhibits IL-4 as well as IL-13-dependent responses. The present study reveals that new types of IL-4 antagonists can be generated by site-specific chemical modification. The chemically modified IL-4 analogues consist of (1) mixed disulfides created by refolding IL-4 cysteine muteins in the presence of different thiol compounds or (2) maleimide conjugates created by modifying cysteine muteins with maleimide derivatives. IL-4 analogues chemically modified at position 121 retain marginal binding affinity to γc or IL-13Rα1 receptor ectodomains during SPR interaction analysis. The biological activity of the analogues is strongly reduced in HEK-Blue IL-4/IL-13 cells as well as in Jurkat cells. Since the IL-4 analogues modified at position 121 have the ability to inhibit γc (IL-4)- and IL13Rα1 (IL-4/IL-13)-dependent responses in Jurkat and HEK-Blue cell lines, they effectively act as IL-4 antagonists. The results of our IL-4 study provide the first example of a cytokine that is transformed into a competitive inhibitor by site-specific chemical modification.
authors.affiliation: Lehrstuhl für Physiologische Chemie II, Theodor-Boveri-Institut für Biowissenschaften (Biozentrum) der Universität Würzburg , Am Hubland, 97074 Würzburg, Germany.
authors.forename: Viswanadham
authors.initials: V
authors.lastname: Duppatla
authors.forename: Maja
authors.initials: M
authors.lastname: Gjorgjevikj
authors.forename: Werner
authors.initials: W
authors.lastname: Schmitz
authors.forename: Heike M
authors.initials: HM
authors.lastname: Hermanns
authors.forename: Carmen M
authors.initials: CM
authors.lastname: Schäfer
authors.forename: Mathias
authors.initials: M
authors.lastname: Kottmair
authors.forename: Thomas
authors.initials: T
authors.lastname: Müller
authors.forename: Walter
authors.initials: W
authors.lastname: Sebald
mesh_terms: D004305:Dose-Response Relationship, Drug; D057809:HEK293 Cells; D006801:Humans; D018793:Interleukin-13 / Q000037:antagonists & inhibitors*; D015847:Interleukin-4 / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000737:chemistry; D019169:Jurkat Cells; D008958:Models, Molecular; D015398:Signal Transduction / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: D018793:Interleukin-13; D015847:Interleukin-4