Engineered human vaccines

Marine gastropod hemocyanins as adjuvants of non-conjugated bacterial and viral proteins

Killed viral vaccines and bacterial toxoids are weakly immunogenic. Numerous compounds are under evaluation as immunological adjuvants and peptide-carriers to improve the immune response. The hemocyanins, giant extracellular copper proteins in the blood of many mollusks, are widely used as immune stimulants. In the present study we investigated the adjuvant properties of hemocyanins isolated from marine gastropods Rapana thomasiana and Megathura crenulata. An immunization with Influenza vaccine or tetanus toxoid combined with Rapana thomasiana hemocyanin (RtH) and Keyhole limpet hemocyanin (KLH) in mice induced an anti-influenza cytotoxic response lasting at least 5 months and an antibody response to viral proteins. The IgG antibody response to the tetanus toxoid (TT) combined with RtH or KLH was comparable to the response of the toxoid in complete Freund's adjuvant. The results obtained demonstrate that the both hemocyanins are acceptable as potential bio-adjuvants for subunit vaccines.

Preclinical safety testing of biotechnology-derived pharmaceuticals: understanding the issues and addressing the challenges

The unique and complex nature of biotechnology-derived pharmaceuticals has meant that it is often not possible to follow the conventional safety testing programs used for chemicals, and hence they are evaluated on a case-by-case basis. Nonclinical safety testing programs must be rationally designed with a strong scientific understanding of the product, including its method of manufacture, purity, sequence, structure, species specificity, pharmacological and immunological effects, and intended clinical use. This knowledge, coupled with a firm understanding of the regulatory requirements for particular product types, will ensure that the most sensitive and regulatory-compliant test systems are used to optimize the chances of gaining regulatory approval for clinical testing or marketing authorization in the shortest possible time frame.