Poster Presentation Australasian Society for Immunology Annual Scientific Meeting 2014

An occupying force of memory T cells against Epstein Barr Virus (#236)

Heng Woon 1 , Corey Smith 2 , Andrew Hislop 3 , Andrew Bell 3 , Alan Rickinson 3 , Stuart Tangye 4 , Rajiv Khanna 2 , Mainthan Palendira 1
  1. Centenary Institute, Newtown, NSW, Australia
  2. QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
  3. School of Cancer Sciences, University of Birmingham, Birmingham, UK
  4. Garvan Institute, Darlinghurst, NSW, Australia

Effective control of infections relies on coordinated trafficking of T cells into tissues and for a long time it was thought that continuous circulation of memory T cells was essential for protective immunity. Growing evidence in mice clearly demonstrate that tissue resident memory T cells are not only distinct from circulating memory T cells, but also provide greater protection against secondary challenge. We have identified tissue resident memory T cells in human tissues and these cells have distinct characteristics when compared to their circulating counterparts. For example, we show a preferential accumulation of CCR7-CD45RA- effector memory and CCR7-CD45RA+ TEMRA CD8+ T cells within the human spleen and these resident memory T cells localise to the T cell areas of the spleen. In order to gain a better understanding of the possible mechanisms that regulate the retention of these resident memory T cells, we examined CD8+ T cells specific for Epstein Barr Virus and Cytomegalovirus. This revealed a selective accumulation of EBV, but not CMV-specific cells, within the human spleen. We also show that residency of memory T cells is unlikely to be driven by the continuos presence of antigen, rather a process regulated by cytokines. To this end, our work shows that the ability to respond to low dose IL-15 may be a key factor that regulates tissue resident memory T cells in humans.