Glaxo Wellcome Inc.

Evans Medical Limited

Other

Burroughs Wellcome Co.

Neil F Fairweather

Ian George Charles

Andrew J Makoff

Steven Neville Chatfield

Jeffrey J Clare

Michael A Romanos

Martin J Lipscombe

The invention concerns a method of prophylactically treating a host against infection by a microorganism, which method comprises administering to the host an attenuated Salmonella bacterium which contains a nirB promoter operably linked to a DNA sequence encoding a heterologous protein. The heterologous protein is expressed in the host and induces in the host an immune response against the microorganism.

Expression of recombinant proteins in attenuated bacteria

A fusion protein suitable for use as a vaccine comprises an amino acid sequence having biological activity which is fused via an intervening hinge comprising from two to eight glycine-proline repeats to the C-terminus of sufficient of the amino acid sequence of a B subunit of an enterotoxin which is capable of ADP-ribosylation of a GTPase.

Fusion proteins

Expression of tetanus toxin fragment C is accomplished employing a DNA coding sequence having a (G+C)-content that has been increased in the region from nucleotide 410 to the 3' end of the coding sequence relative to the wild-type DNA sequence. This allows the production of complete mRNA transcripts. Typically the (G+C)-content is increased in the following regions: (i) nucleotides 510-710, (ii) nucleotides 650-850, (iii) nucleotides 800-1100, (iv) nucleotides 900-1200 and (v) nucleotides 1100-1356. These regions in wild-type DNA encompass terminator sequences.

Expression of tetanus toxin fragment C in yeast

The invention concerns a vaccine comprising an attenuated Salmonella bacterium which contains a nirB promoter operably linked to a DNA sequence encoding a heterologous protein. The nirB promoter directs expression of the heterologous protein in a host it is wished to vaccinate.

The present invention relates to an expression vector encoding mature fragment C of tetanus toxin. The invention further relates to an E. coli host transformed by that vector and to a process for producing mature fragment C of tetanus toxin using same.

Expression of tetanus toxin fragment C

Expression of tetanus toxin fragment C is accomplished employing a DNA coding sequence having a (G+C)-content that has been increased in the region from nucleotide 410 to the 3' end of the coding sequence relative to the wild-type DNA sequence. This allows the production of complete mRNA transcripts. Typically the (G+C)-content is increased in the following regions: (i) nucleotides 510-710, (ii) nucleotides 650-850, (iii) nucleotides 800-1100, (iv) nucleotides 900-1200 and (v) nucleotides 1100 to the 3' end of the coding sequence. The (G+C)-content may also be increased in the region of nucleotides 410-610. These regions in the wild-type DNA encompass terminator sequences.

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Beckenham, United Kingdom

Neil F Fairweather