Vaccine is a substance which has antigens to trigger the immune response against an infection. Before using vaccines, they need to be tested for their efficacy and safety. Different antibody-based assays are used for this purpose; however, methods without relying on antibodies are rare in assessment of vaccine potency. Here we want to suggest a fluorescent ligand-binding of CCR5 Using Tag-lite® Technology as an alternative way of assessing vaccine potency. It is able to detect that CCR5 binds to CCL5, chemokine that plays an important role in migration of effector and memory T cells. This binding makes Th1 cells to secrete IFNγ which participates in tracking of CD8+ responses.
Previously, this technique was used to detect the binding of CXCR4 to SDF1α (CXCR4 is chemokine receptor specific to stromal-derived-factor-1 SDF1α). Here we show the specific binding of CCR5 to CCL5. This Tag-lite ligand binding allows us to assess vaccine potency without relying on conventional antibody assays which are quite expensive. Non-antibody methods may become a good foundation for the development of the ways of assessing the vaccine potency.
In this experiment, we will use Tag-lite IFNγ binding to interferon-gamma receptor (IFNGR) as control group. We expect that the binding of CCR5 to CCL5 will serve as an indicator of immune response by secretion of IFNγ.
In summary, Tag-lite binding technology may serve as an alternative assay for assessing vaccine potency instead of conventional antibody approach.
3. Project description
Vaccines are preparations that contain antigenic substances which trigger specific and active immunity against particular infective agent. Veterinary vaccines are used to improve animal health and welfare thus increasing the livestock and contributing to human health by preventing and controlling the spread of infectious disease from animal to human. (McVey., etc., 2003)
It is necessary to test and evaluate vaccines for efficacy and safety before using them. There are many methods to establish vaccine potency relying on conventional antibody assay approach. However, antibodies are immunogenic, difficult to produce and expensive. (Keefe., etc., 2010) The focus of this proposal is to suggest an alternative method of assessing vaccine potency without relying on antibodies.
Platelets play an important role in protection from infection and are able to secrete chemokines which can attract leukocytes. Activation of platelets leads to the release of several chemokines, particularly CCL5 (Rantes). (Gear, A & Camerini, D. 2003). CCL5 is one of the chemokines which play an important role in immune responses to viral infections. It has an ability to migrate effector and memory T cells during acute infections. It also can attract monocytes, NK cells, eosinophils and dendritic cells. (Crawford, etc., 2011)
CCR5 is the receptor for CCL5 and can be found on the surface of Th1 cells. Th1 cells secrete IFNγ which is the...