RT Journal Article SR Electronic(1) A1 Stentebjerg-Olesen, Bodil A1 Pallesen, Lars A1 Jensen, Lars Bogø A1 Christiansen, Gunna A1 Klemm, PerYR 1997 T1 Authentic display of a cholera toxin epitope by chimeric type 1 fimbriae: effects of insert position and host background JF Microbiology, VO 143 IS 6 SP 2027 OP 2038 DO https://doi.org/10.1099/00221287-143-6-2027 PB Microbiology Society, SN 1465-2080, AB The potential of the major structural protein of type 1 fimbriae as a display system for heterologous sequences was tested. As a reporter-epitope, a heterologous sequence mimicking a neutralizing epitope of the cholera toxin B chain was inserted, in one or two copies, into four different positions in the fim gene. This was carried out by introduction of new restriction sites by PCR-mediated site-directed mutagenesis of fim in positions predicted to correspond to optimally surface-located regions of the subunit protein. Subsequently, the synthetic cholera-toxin-encoding DNA segment was inserted. Several of the chosen positions seemed amenable even for large foreign inserts; the chimeric proteins were exposed on the bacterial surface and the cholera toxin epitope was authentically displayed, i.e. it was recognized on bacteria by specific antiserum. Display of chimeric fimbriae was tested with respect to host background in three different Escherichia coli strains, i.e. an isogenic set of K-12 strains, differing in the presence of an indigenous fim gene cluster, as well as a wild-type isolate. Immunization of rabbits with purified chimeric fimbriae resulted in serum which specifically recognized cholera toxin B chain, confirming the utility of the employed strategy., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-143-6-2027