Recombinant microorganisms

摘要

A method of enhancing expression of a desired protein at mucosal effector sites, said method comprising placing the protein to be expressed under the control of a promoter having SEQ ID NO 2. SEQ ID NO 3 or SEQ ID NO 4 or a fragment or variant or any of these which has promoter activity, and causing expression in mucosal cells. Constructs used in the methods, as well as suitable recombinant gut-colonising microorganisms such as a Salmonella spp. are also described and claimed. Such organisms are useful in the preparation of vaccines.