Massachusetts Institute of Technology researchers recently demonstrated a microfluidic cell-squeezing device that introduces antigens to the body’s immune system’s B cells, a tool that may open a new approach to creating and implementing cell-based, antigen-presenting vaccines.
These types of vaccines, which are developed by manipulating a person’s immune cells to battle invading germs, may be crucial to treating difficult diseases including cancer. Unfortunately, there are still several deficiencies that must be solved before the therapy can be widespread in clinics, and the Food and Drug Administration has approved only one therapy of this kind so far.
Because a B cell is genetically programmed to bind to specific antigens that match the cell’s surface receptors, these B cells usually do not bind and display antigens that do not match their receptors. The microfluidic device makes it possible for the scientists to squeeze the B cells and antigens through tiny, parallel channels designed on a chip. This pressure forces the antigen and immune cell to join.
"We wanted to remove an important barrier in using B cells as an antigen-presenting cell population, helping them complement or replace dendritic cells," Gregory Szeto, a post-doctoral researcher at MIT's Koch Institute for Integrative Cancer Research and the paper's lead author, said. "Down the road, you could potentially get enough cells from just a normal syringe-based blood draw, run it through a bedside device that has the antigen you want to vaccinate against, and then you'd have the vaccine.
Though not involved in this research, Gail Bishop -- a professor of microbiology at the University of Iowa Carver School of Medicine and the director of the school’s Center for Immunology and Immune-based Diseases -- said the antigen-presenting capabilities of B cells have often been underestimated, but they are being increasingly appreciated for their practical advantages in therapies.
"This new technical approach permits loading B cells effectively with virtually any antigen and has the additional benefit of targeting the antigens to the CD8 T-cell presentation pathway, thus facilitating the activation of the killer T cells desired in many clinical applications," Bishop said.