Written by Charles Dueber
Cyclodextrins are composed of sugar molecules bound into a ring called a cyclic oligosaccharide. There are three main types of cyclodextrins: α, β, and γ (shown below). The unique molecular structure of cyclodextrin gives it a hydrophobic interior cavity and hydrophilic exterior, however, the entire molecule is water soluble. This quality has allowed cyclodextrins to be used in the pharmaceutical industry as drug carrier molecules. Recently, it was found that cyclodextrins can be used all by themselves to stimulate the innate immune system. Unpublished data from the University of Wisconsin has shown that zebrafish larvae treated with cyclodextrin and then challenged by lethal concentrations of bacterial LPS had a survival rate of nearly 100% .
My capstone project is looking at whether β-cyclodextrin can be used to stimulate an immune response in the Pacific oyster. I am interested in this because local shellfish hatcheries have had trouble with outbreaks of the bacteria Vibrio tubiashii which can cause significant mortality to larval and juvenile Pacific oyster production (Elston et al. 2008). Unfortunately, few chemical therapeutants have been approved for use in aquaculture especially for prophylactic use. Cyclodextrin could be a novel immune stimulant that has the potential to enhance shellfish production. I recently performed the experiment for my project which consisted of three treatment groups of oysters: control, β-cyclodextrin exposed, and Vibrio tubiashii exposed. Each group was exposed to their corresponding treatment for 24 hours after which gill and mantle samples were taken. RNA was then isolated from the samples and is currently being used to make cDNA. Expression of defense genes will be analyzed via qPCR to determine if there is a difference between oysters in the control, β-cyclodextrin, and V. tubiashii groups. If you're interested in my project you can take a look at my notebook here.