Vaccines protect millions of human lives per year from otherwise fatal illnesses. Vaccination promotes immunity by simulating infection with a non-pathogenic representative of the disease, an antigen, to prepare and train an immune response. Vaccine-safe antigens are often too small to elicit an immune response. These non-immunogenic molecules are referred to as haptens and are introduced to the immune system by hapten-carriers, large immune-stimulating proteins. Keyhole Limpet Hemocyanin (KLH), a respiratory protein of the giant keyhole limpet (Megathura crenulata), is the industry standard hapten-carrier. KLH is a potent yet safe immune-stimulant relied upon in research, available human medications, and emerging vaccines. KLH is currently valued at approximately $10,000 per gram, and economic analysis predicts the KLH market to exceed $35 million once new vaccines are approved. KLH production, however, is neither ecologically sustainable nor economically sensible. KLH is produced from live M. crenulata and cannot be synthesized. Over-fishing endangers wild M. crenulata populations, and only one company is authorized to aquaculture this species. A potential alternative hapten-carrier is the hemocyanin from the red abalone (Haliotis rufescenes). Aquaculture for this species is well established and globally profitable; their meat is considered a delicacy, and their shell is the source of the gem ‘Mother of Pearl’. Red abalone hemocyanin (RAH) is biochemically similar to KLH. This study adapts KLH purification techniques to RAH for comparison. KLH and RAH were determined to be approximately the same molecular weight, a critical characteristic for an alternative hapten-carrier. RAH isolation was optimized to rival commercial KLH purity. RAH, like KLH, consists of two subunits between 350 kDa and 400 kDa. RAH elicits an antibody production response to conjugated haptens in mice. RAH is therefore a viable alternative to KLH as a hapten-carrier in vaccine production. There is precedent for abalone aquaculture in Maine.
Mansour, Isaiah N., "Red Abalone Hemocyanin as an Alternative Hapten-Carrier for Vaccine Production" (2018). Honors College. 349.