A graduate student decides to create a vaccine to an intracellular bacterium. Th
ID: 100289 • Letter: A
Question
A graduate student decides to create a vaccine to an intracellular bacterium. The student decides that the vaccine would be most effective if it generated a strong antigen-specific T-cell response. This bacterium has a non-glycosylated membrane receptor, protein X, that enables it to attach to host cells. The student decides that this protein would make a good antigen for a vaccine. The student injects protein X alone into mice and looks for antigen-specific T-cells. To his/her surpise the mice never generate antigen specific T-cells. What aspect of naive T-cell activation has this student not considered? What could they do to improve the liklihood of generating antigen-specific T-cell to protein X?
Explanation / Answer
The adaptive immune system or the acquired immune system works on the ability to differentiate ‘self’ antigens from pathogen-derived antigens. The MHC family is structurally and genetically associated glycoproteins that provide a key role in this method by controlling T-cell activation. The T-cell activation require processed antigen from dendrite cells (DC) or macrophages, Langerhans cells and B cells like antigen presenting cells (APCs). Glycosylated peptides can bind and present by MHC class I and II molecules and educe glycopeptide-specific T cell clone. The protein that inserted was not glycosylated. Nowadays antigen glycosylation is a key for many of diseases and vaccine designs.
Therefore, the glycosylated protein X may have chance of providing the positive result.