By Briga Mullin, Biochemistry and Molecular Biology, ’15
What do a smoker, a two week old embryo, a child with a broken wrist, and a metastatic tumor all have in common? While these are a diverse group of conditions, they all have cells that are experiencing the same process known as epithelial-mesenchymal transition (EMT). Mesenchymal cells are non-polarized, mobile, invasive, and their main function is to secrete extracellular matrix. In contrast, epithelial cells form our skin and the linings of our internal organs. They are normally polarized which means they have a directional structure and are uniformly oriented and are attached to a membrane to form a layer of epithelial tissue. Under certain conditions an EMT will occur and epithelial cells will change their transcription patterns, produce new proteins, destroy the basal membrane they are attached to, and totally convert their phenotype to become motile mesenchymal cells. EMT can be triggered by a variety of conditions and can yield very beneficial or extremely detrimental results depending on the circumstances. Continue reading From Embryo to Tumor: the widespread applications of Epithelial-Mesenchymal Transition
By David Ivanov, Biochemistry ’15
Oral vaccines are known to be a convenient and effective method for treatment or prevention of diseases caused by pathogenic microorganisms. The difficulty of developing such vaccines is due to the often inhospitable environment of the stomach and intestinal tract because of low pH, or acidity, as well as enzymes that can digest or destroy biological molecules. Using a virus-like particle to deliver the vaccine is an advantageous method for getting around these and other barriers in the host organism.
A virus-like particle, or VLP, is a biological particle that resembles a virus, but contains no genetic information and thus cannot infect host cells. VLP’s can be formed by inserting and expressing just the genes for creating the viral capsid, which is a shell made up of protein subunits that protects the infectious genetic information in wild-type, or normal, viruses. The expressed capsid proteins can then self-assemble into the VLP. The capsid also has domains, or structural areas, that are responsible for recognizing suitable host cells to infect and inserting the viral genome.
Continue reading Engineering Hepatitis Virus-like Particles for Oral Vaccine Delivery