| TECHNOLOGY |
Cell-based sensors respond to pathogens
Immune cells known as B lymphocytes can be used in cell-based sensors to identify pathogens. researchers engineer B lymphocyte cell lines that express cytosolic aequorin, a calcium-sensitive bioluminescent protein from a jellyfish, and membrane-bound antibodies specific for the pathogen of interest. When the pathogen is present, the antibodies are cross-linked and the calcium levels in the cell increase, causing the aequorin to emit light. In one example, authors engineered cells to respond to Yersinia pestis, the bacterium that causes plague. The sensor could detect as few as 50 colony-forming units of the bacterium in less than three minutes. The cells didn't respond to the unrelated bacterium Francisella tularensis, nor did large amounts of F. tularensis prevent the cells from responding to Y. pestis. The team has already made about a dozen different sensors for pathogens such as smallpox and anthrax.
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