Development of DNA vaccines against hemolytic-uremic syndrome in a murine model.
Shiga toxin type 2 (Stx2) produced by Escherichia coli O:157H7 can cause hemolytic-uremic syndrome in children, a disease for which there is neither a vaccine nor an effective treatment. This toxin consists of an enzymatically active A subunit and a pentameric B subunit responsible for the toxin binding to host cells, and also found to be immunogenic in rabbits. In this study we developed eukaryotic plasmids expressing the B subunit gene of Stx2 (pStx2B) and the B subunit plus the gene coding for the A subunit with an active-site deletion (pStx2 Delta A). Transfection of eukaryotic cells with these plasmids produced proteins of the expected molecular weight which reacted with specific monoclonal antibodies. Newborn and adult BALB/c mice immunized with two intramuscular injections of each plasmid, either alone or together with the same vector expressing the granulocyte and monocyte colony-stimulating factor (pGM-CSF), elicited a specific Th1-biased humoral response. The effect of pGM-CSF as an adjuvant plasmid was particularly notable in newborn mice and in pStx2B-vaccinated adult mice. Stx2-neutralizing activity, evaluated in vitro on VERO cell monolayers, correlated with in vivo protection. This is the first report using plasmids to induce a neutralizing humoral immune response against the Stx2.
Capozzo
Alejandra V E
AV
Instituto de Investigaciones Hematológicas, Academia Nacional de Medicina, Buenos Aires, Argentina.
Pistone Creydt
Virginia
V
Dran
Graciela
G
Fernández
Gabriela
G
Gómez
Sonia
S
Bentancor
Leticia V
LV
Rubel
Carolina
C
Ibarra
Cristina
C
Isturiz
Martín
M
Palermo
Marina S
MS
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D004195:Disease Models, Animal; D022361:Escherichia coli Vaccines / Q000276:immunology*; D006463:Hemolytic-Uremic Syndrome / Q000517:prevention & control*; D007074:Immunoglobulin G / Q000097:blood / Q000145:classification; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D010957:Plasmids; D022641:Shiga Toxin 2 / Q000276:immunology*; D014162:Transfection; D019444:Vaccines, DNA / Q000276:immunology*
D000907:Antibodies, Bacterial; D022361:Escherichia coli Vaccines; D007074:Immunoglobulin G; D022641:Shiga Toxin 2; D019444:Vaccines, DNA