RESUMO
Current source of recombinant human interleukin-11 (rhIL-11) is isolated from a fusion protein expressed by E. coli that requires additional enterokinase to remove linked protein, resulting in product heterogeneity of N-terminal sequence. Due to lack of glycosylation, rhIL-11 is suitable to be expressed by yeast cells. However, the only available yeast-derived rhIL-11 presents an obstacle in low production yield, as well as an unamiable process, such as the use of reverse-phase chromatography employing plenty of toxic organic solvents. Our findings showed that the low yield was due to self-aggregation of rhIL-11. A novel process recovering bioactive rhIL-11 from the yeast secretory medium therefore has been developed and demonstrated, involving fermentation from Pichia pastoris, followed by a two-phase extraction to precipitate rhIL-11. After renaturing, the protein of interest was purified by a two-column step, comprising a cation-exchanger, and a hydrophobic interaction chromatography in tandem at high sample loads that was facile and cost-effective in future scale-up. Identity and quality assessments confirmed the expected amino acid sequence without N-terminal heterogeneity, as well as high quality in potency and purity. Such a process provides an alternative and adequate supply of the starting material for the PEGylated rhIL-11.
Assuntos
Interleucina-11/genética , Pichia/genética , Linhagem Celular , Proliferação de Células , Cromatografia em Gel , Clonagem Molecular/métodos , Fermentação , Expressão Gênica , Humanos , Interleucina-11/química , Interleucina-11/isolamento & purificação , Interleucina-11/metabolismo , Pichia/metabolismo , Agregados Proteicos , Redobramento de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , SolubilidadeRESUMO
Treating thrombocytopenia induced by chemotherapy remains an unmet-medical need. The use of recombinant human interleukin-11 (rhIL-11) requires repeated injections and induces significant fluid retention in some patients. Modification of human interleukin-11 with chemically inert polyethylene glycol polymer (PEG) may extend the peripheral circulation half-life leading to an improved pharmacokinetic and pharmadynamic profile. In this study, a number of rhIL-11 PEG conjugates were created to determine the optimal approach to prolong circulating half-life with the most robust pharmacological effect. The lead candidate was found to be a single 40-kDa Y-shaped PEG linked to the N-terminus, which produced a long-lasting circulating half-life, enhanced efficacy and alleviated side effect of dilutional anemia in healthy rat models. This candidate was also shown to be effective in myelosuppressive rats in preventing the occurrence of severe thrombocytopenia while ameliorating dilutional anemia, compared to rats receiving daily administration of unmodified rhIL-11 at the same dose. These data indicated that a single injection of the selected modified rhIL-11 for each cycle of chemotherapy regimen is potentially feasible. This approach may also be useful in treating patients of acute radiation syndrome when frequent administration is not feasible in a widespread event of a major radiation exposure.