Research on DNA vaccines detailed by L.V. Bentancor and co-authors
2009 JUL 8 - (NewsRx.com) -- According to recent research from Buenos Aires, Argentina, "Production of verocytotoxin or Shiga-like toxin (Stx), particularly Stx2, is the basis of hemolytic uremic syndrome, a frequently lethal outcome for subjects infected with Stx2-producing enterohemorrhagic Escherichia coli (EHEC) strains. The toxin is formed by a single A subunit, which promotes protein synthesis inhibition in eukaryotic cells, and five B subunits, which bind to globotriaosylceramide at the surface of host cells." "Host enzymes cleave the A subunit into the A(1) peptide, endowed with N-glycosidase activity to the 28S rRNA, and the A(2) peptide, which confers stability to the B pentamer. We report the construction of a DNA vaccine (pStx2 Delta AB) that expresses a nontoxic Stx2 mutated form consisting of the last 32 amino acids of the A(2) sequence and the complete B subunit as two nonfused polypeptides. Immunization trials carried out with the DNA vaccine in BALB/c mice, alone or in combination with another DNA vaccine encoding granulocyte-macrophage colony-stimulating factor, resulted in systemic Stx-specific antibody responses targeting both A and B subunits of the native Stx2. Moreover, anti-Stx2 antibodies raised in mice immunized with pStx2 Delta AB showed toxin neutralization activity in vitro and, more importantly, conferred partial protection to Stx2 challenge in vivo," wrote L.V. Bentancor and colleagues. The researchers concluded: "The present vector represents the second DNA vaccine so far reported to induce protective immunity to Stx2 and may contribute, either alone or in combination with other procedures, to the development of prophylactic or therapeutic interventions aiming to ameliorate EHEC infection-associated sequelae." Bentancor and colleagues published their study in Clinical and Vaccine Immunology (A DNA Vaccine Encoding the Enterohemorragic Escherichia coli Shiga-Like Toxin 2 A(2) and B Subunits Confers Protective Immunity to Shiga Toxin Challenge in the Murine Model. Clinical and Vaccine Immunology, 2009;16(5):712-718). For additional information, contact M.S. Palermo, Academy Nacl Med Buenos Aires, Laboratory Inmunol IIHema, P de Melo 3081, RA-1425 Buenos Aires, DF, Argentina. Publisher contact information for the journal Clinical and Vaccine Immunology is: American Society Microbiology, 1752 N St. NW, Washington, DC 20036-2904, USA. Keywords: Argentina, Buenos Aires, Amino Acids, Biotechnology, DNA Research, DNA Vaccines, Drugs, Enzyme Research, Escherichia coli, Glycosidase, Hematology, Hemolytic-Uremic Syndrome, Immunization, Immunology, Medical Device, Peptide, Pharmaceuticals, Protein Synthesis, Proteins, Proteomics, Therapy, Treatment, Vaccination. This article was prepared by Vaccine Weekly editors from staff and other reports. Copyright 2009, Vaccine Weekly via NewsRx.com.
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