Repurposed therapeutic used in conjunction with vaccination boosts the number of antigen-specific, high quality memory T cells.
- Novel use for FDA-approved repurposed therapeutic.
- Administration during a traditional vaccination protocol boosts acquired immunity by increasing the stock of memory T cells.
Vaccines are designed to strengthen the acquired immune response by increasing the stock of rare antigen-specific memory T cells, however this process is often inefficient, requiring multiple boosters to achieve immunity. The time between the prime and boost vaccine delays the patient's immunization and requires multiple visits to the clinic, therefore methods for improving vaccines are highly desired. Dr. Ahmed and colleagues at Emory University's Vaccine Center have discovered that administration of an FDA approved therapeutic, rapamycin, dramatically increases the number of memory T cells during vaccination. Immunization with a foreign antigen induces a complex response including proliferation and differentiation of T cells that give rise to an effector population. During the subsequent contraction phase, 90- 95% of these cells undergo apoptosis, while a small subset differentiate and remain as circulating, memory T cells. These antigen-specific cells are prepared to reactivate the immune response if the body encounters this same pathogen again. Because the height of the effector cell population and therefore a robust immune response reflects the number of activated memory cells, boosting this population is a desired result of vaccination. Dr. Ahmed has discovered that proper timing and dosing of this FDA approved therapeutic during immunization results in an increase in high quality memory T cells that respond to future pathogen challenges more efficiently than untreated controls. This technology therefore offers a safe, effective, quick-to-market strategy for enhancing existing vaccine protocols.
Proof-of-principle experiments have demonstrated increased numbers of high quality memory T cells and enhance the immune response to antigen challenges in a rodent model.