Claims for Patent: 5,538,885

Summary for Patent: 5,538,885

Title:	Expression systems
Abstract:	Expression systems which comprise a mammalian host, such as erythroid cells, transformed with a vector which comprises a promoter, a DNA sequence which codes for a desired polypeptide and a dominant control region. The vectors and methods for preparing polypeptides using the expression systems are also described. In a preferred embodiment, the vector contains cDNA for the desired polypeptide and a sequence which is capable of stabilising mRNA produced from the cDNA. The expression systems are particularly efficient and are capable of secreting the desired polypeptide.
Inventor(s):	Hollis; Melvyn (Cheshire, GB2), Needham; Maurice R. C. (Cheshire, GB2), Gooding; Clare (Cheshire, GB2), Grosveld; Franklin G. (London, GB2), Antoniou; Michael (London, GB2)
Assignee:	Imperial Chemical Industries PLC (London, GB)
Application Number:	08/186,895
Patent Claims:	1. An expression system which comprises murine erythroleukemia cells transformed with a vector which comprises (i) the human beta-globin promoter, (ii) a genomic DNA sequence which codes for a polypeptide heterologous to said murine erythroleukemia cells and (iii) a dominant control region, and wherein after induction of differentiation of said murine erythroleukemia cells, said polypeptide is secreted by said murine erythroleukemia cells. 2. The expression system of claim 1 wherein the dominant control region comprises a micro locus which comprises a 6.5 kb fragment obtained by ligating the fragments: 2.1 kb XbaI - XbaI; 1.9 kb HindIII - HindIII; 1.5 kb KpnI - BgIII; and 1.1 kb partial SacI; from the .beta.-globin gene. 3. A method of preparing a polypeptide, said method comprising cultivating the expression system according to claim 1. 4. An expression system which comprises murine erythroleukemia cells transformed with a vector which comprises (i) the human beta-globin promoter, (ii) the second exon/intron, 3rd exon and polyadenylation sequence, all of the human beta-globin gene, (iii) a cDNA sequence which codes for a polypeptide and (iv) a dominant control region, and wherein after induction of differentiation of said murine erythroleukemia cells, said polypeptide is secreted by said murine erythroleukemia cells. 5. The expression system of claim 4 wherein the dominant control region comprises a micro locus which comprises a 6.5 kb fragment obtained by ligating the fragments: 2.1 kb XbaI - XbaI; 1.9 kb HindIII - HindIII; 1.5 kb KpnI - BgIII ; and 1.1 kb partial SacI; from the .beta.-globin gene. 6. A method of preparing a polypeptide, said method comprising cultivating the expression system according to claim 4.

Details for Patent 5,538,885

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Merck Sharp & Dohme Corp.	INTRON A	interferon alfa-2b	For Injection	103132	06/04/1986		2013-07-23
Merck Sharp & Dohme Corp.	INTRON A	interferon alfa-2b	For Injection	103132			2013-07-23
Merck Sharp & Dohme Corp.	INTRON A	interferon alfa-2b	Injection	103132			2013-07-23