Apr 20th, 1:00 PM - 4:00 PM
Purification of Novel Shiga Toxin Based Vaccine
Dr. Juliette Tinker
Many parts of the world go without effective vaccination programs because they lack the medical infrastructure to provide sterile environments for intravenous administration of vaccines. The construction and development of stable oral vaccines would greatly increase vaccination rates in parts of the world where sterile environments are not available, and would also represent a significant improvement in developed countries. However, mucosal vaccines require the presence of a “helper” substance, or adjuvant. The protein toxins expressed by a number of gram negative bacteria, including Shiga toxin (Stx) produced by enterohemorrhagic E. coli (EHEC) represent promising mucosal vaccine adjuvants. The purpose of this experiment is to purify a detoxified derivative of Shiga toxin that is a fusion, or chimera, of the toxin with a vaccine antigen of interest. These experiments have focused on the successful cloning of a 6x histidine tag to a plasmid containing the genes for the Stx A2/B genes. This construct will allow for rapid purification of novel toxin chimeras on nickel columns. We have used molecular techniques to successfully insert a 6x His tag into the Stx plasmid. The LcrV antigen from Yersinia pestis as well as a red fluorescent protein (RFP) will be cloned into this novel expression vector, creating chimeras of the StxA2/B subunits that can be purified using the 6x His tag and characterized as potential oral vaccines.