IL-15:IL-15 receptor alpha superagonist complex: high-level co-expression in recombinant mammalian cells, purification and characterization.
IL-15, a promising cytokine for treating cancer and viral diseases, is presented in trans by the IL-15 receptor (IL-15R) alpha-chain to the IL-15Rβγc complex displayed on the surface of T cells and natural killer (NK) cells. We previously reported that an asparagine to aspartic acid substitution at amino acid 72 (N72D) of IL-15 provides a 4-5-fold increase in biological activity compared to the native molecule. In this report, we describe Chinese hamster ovary (CHO) cell expression of a soluble complex (IL-15 N72D:IL-15RαSu/Fc) consisting of the IL-15 N72D superagonist and a dimeric IL-15Rα sushi domain-IgG1 Fc fusion protein. A simple but readily scalable affinity and ion exchange chromatography method was developed to highly purify the complex having both IL-15 binding sites fully occupied. The immunostimulatory effects of this complex were confirmed using cell proliferation assays. Treatment of mice with a single intravenous dose of IL-15N72D:IL-15RαSu/Fc resulted in a significant increase in CD8+ T cells and NK cells that was not observed following IL-15 treatment. Pharmacokinetic analysis indicated that the complex has a 25-h half-life in mice which is considerably longer than <40-min half-life of IL-15. Thus, the enhanced activity of the IL-15N72D:IL-15RαSu/Fc complex is likely the result of the increased binding activity of IL-15N72D to IL-15Rβγc, optimized cytokine trans-presentation by the IL-15RαSu domain, the dimeric nature of the cytokine domain and its increased in vivo half-life compared to IL-15. These findings indicate that this IL-15 superagonist complex could serve as a superior immunostimulatory therapeutic agent.
Altor BioScience Corporation, 2810 North Commerce Parkway, Miramar, FL 33025, USA.
Kai-ping
KP
Han
Xiaoyun
X
Zhu
Bai
B
Liu
Emily
E
Jeng
Lin
L
Kong
Jason L
JL
Yovandich
Vinay V
VV
Vyas
Warren D
WD
Marcus
Pierre-Andre
PA
Chavaillaz
Christian A
CA
Romero
Peter R
PR
Rhode
Hing C
HC
Wong
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D016466:CHO Cells; D002469:Cell Separation; D002850:Chromatography, Gel; D006224:Cricetinae; D003412:Cricetulus; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D019409:Interleukin-15 / Q000819:agonists* / Q000302:isolation & purification*; D053720:Interleukin-15 Receptor alpha Subunit / Q000819:agonists* / Q000302:isolation & purification*; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008322:Mammals / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D050505:Mutant Proteins / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology; D011995:Recombination, Genetic / Q000235:genetics*
D019409:Interleukin-15; D053720:Interleukin-15 Receptor alpha Subunit; D050505:Mutant Proteins; D011993:Recombinant Fusion Proteins