The human immune system is composed of three principle branches: Innate Immunity, Cellular (or T cell) immunity and Humoral (or B cell) immunity.
Despite these three branches and the multitude of immune cell types, the diagnostic world has only largely embraced antibodies. Leveraging our T-SPOT technology, Oxford Immunotec is one of the few companies to focus on standardizing T cell and innate immunity measurements. Our T-SPOT technology gives us a unique toolbox to develop proprietary tests based on prosecuting the previously unexploited T cell and innate immunity branches of the immune system.
Our proprietary T-SPOT technology measures immune cell responses at a single cell level. Our technology studies the responses of living T cells and innate immune cells, which gives us a direct window into the immune system.
Simplistically, the technology starts with a blood sample obtained through a standard blood collection tube from which white blood cells, or WBC’s, are separated and purified. The cells are quantified and placed into specially designed plates where they are challenged with antigens specific to the disease under study. Disease-specific cells responding to these antigens will release immune messenger molecules, called cytokines. We then use chemistry to allow us to visualize those WBCs releasing cytokines (and hence those which react to the antigen), resulting in a spot on the bottom of the plate, corresponding to the footprint of an individual reacting WBC. Finally, we use an automated image analysis system to identify and count each of these spots to give a quantitative readout. That quantitative readout gives us the frequency of responsive disease-specific cells.
The exquisite sensitivity afforded by single-cell resolution is key to the platform’s applicability across different areas of medicine. This is because, for many conditions, the frequency of T cells or innate immune cells can be very low. Our technology has the ability to detect an individual reacting cell in a population of 250,000 white blood cells.
Because we always standardize the number of cells used in each assay, we can compare responses over time to a common standard. It is this normalization of the sample that makes longitudinal measurement valid and the platform well-suited for monitoring applications.
The sensitivity of the T-SPOT platform, as well as its use for monitoring applications, are two of many reasons why this technique has key advantages over other technologies, such as ELISA.