Anti-infective therapy

Abstract

DNA isolates coding for human DNase and methods of obtaining such DNA are provided, together with expression systems for recombinant production of human DNase useful in therapeutic or diagnostic compositions.

1 . A DNA isolate encoding human DNase polypeptide having the amino acid sequence shown in  FIG. 1  or a variant thereof incorporating at least one of the amino acid substitutions selected from the group consisting of: H134K, N, R or Q; A135S; L133V, I or A; P132A; N18K, H, R or Q; S17T; T20S or Y; N106K, H, R or Q; G105P or A; D107E or T; R140A; R121K or H; T108S or Y; P103S, T or Y; C101S, T, Y or M; C104S, T, Y or H; F6W, L, I, M or V; I8F, L, V, M or W; R41K or H; S43T, C or Y; K77R or H; R79K or H; N110D, S, T, R, Y or Q; G167P; F169L, V, I or M; A171G, V or M; S250T, Y or M; Y253T, S or M; R73N; R73C and D139C; K260R or S; or L259V, I or M.  
     
     
         2 . The isolate of  claim 1  wherein the isolate is free of DNase introns.  
     
     
         3 . The isolate of  claim 1  wherein the isolate is free of genomic DNA which encodes another polypeptide from the source of the DNA.  
     
     
         4 . A recombinant expression vector comprising DNA encoding human DNase or a variant thereof according to  claim 1 .  
     
     
         5 . A composition comprising a cell transformed with the recombinant expression vector of  claim 4 .  
     
     
         6 . The composition of  claim 5  wherein the cell is a mammalian cell.  
     
     
         7 . A process for producing human DNase or a variant thereof according to  claim 1  which comprises transforming a host cell with nucleic acid encoding DNase, culturing the transformed cell and recovering DNase from the culture.  
     
     
         8 . The process according to  claim 7  wherein the DNase or variant thereof is recovered from the culture medium of the host cell.  
     
     
         9 . The process according to  claim 8  wherein the host cell is a eukaryotic cell.  
     
     
         10 . The process of  claim 9  wherein the eukaryotic cell is a human embryonic kidney cell line.  
     
     
         11 . The process of  claim 9  wherein the nucleic acid encodes a preprotein human DNase or a variant thereof.  
     
     
         12  The process of  claim 9  wherein the DNase or variant thereof is secreted into the culture medium.  
     
     
         13 . The process of  claim 9  wherein the DNase or variant thereof is unglycosylated.