New diagnostic tool promises ultrasensitive detection

Lynes image

     When doctors order lab tests to diagnose diseases, they want fast, reliable results using a small sample for patient comfort. This requires a highly sensitive device that processes many samples at once. A new technology being developed by Prof. Michael Lynes and his partner, Ciencia of East Hartford, promises to provide doctors with swift, sensitive detection of disease indicators in small clinical samples.

     Lynes and Ciencia recently won 3 grants totaling about $600,000 from NIH Small Business Innovation Research programs to continue developing their grating coupled surface plasmon resonance (GC-SPR) devices to increase their sensitivities to toxins and pathogens. These Phase I grants allow them to develop prototype GC-SPR devices so they can apply later for Phase II funds for field-tests.

T cells bound to 4 sites on a GC-SPR sensor

 Lynes’ GC-SPR devices detect analytes (molecules, pathogens or mammalian cells) in fluids by passing those fluids over a surface coated with antibodies that bind them.  Analytes can be toxins or even whole cells with molecules on their surfaces that are recognized by the antibodies. A major challenge is to improve the GC-SPR devices’ sensitivity. "When you get down to those levels of detection, the signal to noise ratio can be improved by fixing noise," Lynes said. To remove the noise, the team employs small gold beads called nanobeads. The nanobeads are coated with the desired analyte and enhance its binding to the antibodies (the signal) while inhibiting binding by non-analytes (the noise).

     Pathogens that infect mice are a major problem in colonies kept for research. Detecting pathogens living with other microbes in “polymicrobial” infections is an important application of GC-SPR. Lynes is working in this area with long-time collaborators at The Jackson Laboratory, recent partners with UConn on the Center for Genomic Medicine now under construction in Farmington. “There are polymicrobial infections in research collections that are very difficult to identify," Lynes said. "It is hard to know which mice to test." Lynes’ method promises to detect as few as 30 bacterial cells in a milliliter of sample. A rapid test using small samples would allow caretakers to identify and remove only infected mice and not eliminate the entire colony as is often necessary now. Once developed, this technology may be used for human diagnoses where its lower cost per assay will make routine surveillance commonplace.

Lynes Michael photo

     One grant allows Lynes and his collaborators to devise a GC-SPR method to detect the earliest development of Type 1 diabetes. Type 1 diabetes, sometimes called juvenile diabetes, results when the T cells in a person’s immune system incorrectly create an immune response to the islet cells needed to make insulin and in so doing destroy them. Current methods to identify these “autoreactive” T cells are slow and require large clinical samples, a drawback when testing children.

     Lynes’ GC-SPR device will attempt to detect these autoreactive T cells in clinical samples and test them to see if they are active in beginning to elicit the destructive immune response. Lynes asks, "Is the reason that a non-diabetic doesn't develop symptoms, yet has those cells, because the cells have somehow been turned off or is it because they have not yet encountered the right environmental stimulus to turn them on?" GC-SPR analysis might provide an answer and allow early detection of the disorder. Thus a doctor might "get in early enough to do a little bit of manipulation rather than give life-long injections of insulin or stem cells," Lynes said.

     Lynes’ GC-SPR technologies resulted from a decade collaboration with Ciencia and David Lawrence at the Wadsworth Center. Much of this work is covered under a broad patent awarded to Lynes and Dr. Salvador Fernandez, the late founder, President and CEO of Ciencia. Advances in GC-SPR clinical devices continue and promise to provide sensitive, high-throughput diagnostic tools.