Method for rapidly screening microbial hosts to identify certain strains with improved yield and/or quality in the expression of heterologous proteins

摘要

The present invention provides an array for rapidly identifying a host cell population capable of producing a heterologous protein with improved yield and/or quality. The array comprises one or more host cell populations that have been genetically modified to increase the expression of one or more target genes involved in protein production, decrease the expression of one or more target genes involved in protein degradation, or both. One or more of the strains in the array may express the heterologous protein of interest in a periplasm compartment or may secrete the heterologous protein extracellularly through an outer cell wall. The strain arrays are useful for screening for improved expression of any protein of interest including therapeutic proteins, hormones, growth factors, extracellular receptors or ligands, proteases, kinases, blood proteins, chemokines, cytokines, antibodies and the like.

主权项

1. A method of assembling an array and using the array to simultaneously screen at least 10 nonidentical expression systems for testing expression of at least one heterologous recombinant protein, said method comprising:
placing Pseudomonad or E. coli host cell populations in separate addressable locations of the array; introducing at least one expression vector encoding the at least one heterologous recombinant protein into each host cell population in the array to produce each of the at least 10 nonidentical expression systems in the array, wherein the array of at least 10 nonidentical expression systems includes at least 5 different host cell populations and at least 2 different expression vectors, wherein at least 3 of said at least 5 different host cell populations are deficient in their expression of at least one host cell protease, wherein the at least 10 nonidentical test expression systems in the array each comprises a different combination of a) a Pseudomonad or E. coli host cell population, and b) at least one of the at least 2 different expression vectors encoding the at least one heterologous recombinant protein, and simultaneously screening the at least 10 nonidentical test expression systems on the array; wherein at least one expression system in the array of the at least 10 nonidentical test expression systems overexpresses the at least one heterologous recombinant protein.