What is ELISpot
ELISpot is a useful tool used in medical research and diagnostics to assess immune cell activity, particularly their capacity to release cytokines. ELISpot, an abbreviation for enzyme-linked immunospot assay, is a variation on the popular ELISA test. To assess the immune response to a particular antigen, this method is frequently employed in basic research, clinical trials, and the creation of vaccines.
The ELISpot assay counts the number of spots or clusters that these cells create when cytokines are captured on a solid membrane in order to detect individual cytokine-secreting cells. The test is based on the ELISA (enzyme-linked immunosorbent assay) concept, which is used to find out whether a sample contains a particular protein. The ELISpot assay, on the other hand, differs in that it counts the number of cells that release a particular cytokine in response to a stimulus.
ELISpot assays offer a sensitive and accurate way to find cells that release cytokines. It provides a variety of benefits over other methods for calculating cytokine production, including the ability to identify cells that only produce little amounts of cytokines, high sensitivity, and accurate evaluation of cytokine production potential at the single-cell level.
Figure 1. The process of ELISpot.
An antibody that is specific to the target cytokine is first bonded to a nitrocellulose membrane in order to perform the ELISpot experiment. The cells of interest are then introduced to the membrane and activated by a particular antigen or mitogen to cause the generation of cytokines. Following an incubation period, the cells are taken out, and the membrane is washed to get rid of any cytokines or unbound cells. A secondary antibody linked to an enzyme like alkaline phosphatase or horseradish peroxidase, which catalyzes a process that results in a colored or fluorescent product, is then used to quantify the bound cytokines. The number of cytokine-secreting cells in the sample is positively correlated with the number of spots on the membrane.
The immune response to a range of stimuli, including as vaccinations, infectious diseases, and cancer cells, can be assessed using ELISpot tests. ELISpot tests are employed in the context of vaccine development to assess a vaccine's efficacy by assessing the immune response to the vaccination antigen. For instance, the quantity of interferon-gamma-secreting T cells in response to a tuberculosis vaccine could be counted using an ELISpot assay. ELISpot can also be used in infectious disease studies to gauge the immune response to certain pathogens such the hepatitis B virus. In addition, ELISpot tests can also be used in cancer research to gauge how well immune cells are able to combat cancer cells.
Although the ELISpot assay has numerous benefits, it also has significant drawbacks. One drawback is that it takes a lot of time and effort because the assay calls for the use of specialized tools and trained staff. Its functional nature, which evaluates cytokine production rather than the total number of cytokines in the sample, is another drawback. This means that cytokine-secreting cells that are present in extremely small numbers or that have low cytokine production levels may be undetected by the assay.
The ELISpot assay is a useful technique for assessing the immune response to particular stimuli, to sum up. It is a popular choice for a variety of applications, including vaccine development, research into infectious diseases, and cancer immunotherapy, due to its high sensitivity, specificity, and capacity to detect cytokine-secreting cells at the single-cell level.
