Optimization of Salmonella enterica serovar typhi DeltaaroC DeltassaV derivatives as vehicles for delivering heterologous antigens by chromosomal integration and in vivo inducible promoters.
Novel candidate live oral vaccines based on a Salmonella enterica serovar Typhi ZH9 (Ty2 DeltaaroC DeltassaV) derivative that directed the expression of either the B subunit of Escherichia coli heat-labile toxin or hepatitis B virus core antigen from the bacterial chromosome using the in vivo inducible ssaG promoter were constructed. The levels of attenuation of the two S. enterica serovar Typhi ZH9 derivatives were similar to that of the parent as assessed by measuring the replication of bacteria within human macrophage-like U937 cells. The expression of heterologous antigen in the respective S. enterica serovar Typhi ZH9 derivatives was up-regulated significantly within U937 cells compared to similar S. enterica serovar Typhi ZH9 derivative bacteria grown in modified Luria-Bertani broth supplemented with aromatic amino acids. Immunization of mice with these S. enterica serovar Typhi ZH9 derivatives stimulated potent antigen-specific serum immunoglobulin G responses to the heterologous antigens.
Stratford
Richard
R
Microscience Ltd., 540-545 Eskdale Rd., Winnersh Triangle, Wokingham, Berkshire RG41 5TU, United Kingdom. r.stratford@microscience.com
McKelvie
Nicola D
ND
Hughes
Nicky J
NJ
Aldred
Emma
E
Wiseman
Claire
C
Curtis
Johanna
J
Bellaby
Trevor
T
Bentley
Matt
M
Hindle
Zoë
Z
Brennan
Frank R
FR
Chatfield
Steven N
SN
Dougan
Gordon
G
Khan
Shahid A
SA
D000281:Administration, Intranasal; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001427:Bacterial Toxins / Q000235:genetics*; D002876:Chromosomes, Bacterial; D004768:Enterotoxins / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics*; D005260:Female; D005822:Genetic Vectors; D006512:Hepatitis B Core Antigens / Q000235:genetics*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D051379:Mice; D008807:Mice, Inbred BALB C; D011401:Promoter Regions, Genetic; D012485:Salmonella typhi / Q000235:genetics* / Q000276:immunology; D020298:U937 Cells
D000907:Antibodies, Bacterial; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D006512:Hepatitis B Core Antigens; D007074:Immunoglobulin G; C027538:heat-labile enterotoxin, E coli