Is T-cell memory maintained by crossreactive stimulation?

Whether or not T- and B-cell memory is antigen driven remains unresolved. Recent studies indicate that, in humans, naive and memory T cells can be distinguished by their expression of different CD45 isoforms. Extensive phenotypic analysis of naive and memory T cells shows that the latter express greater amounts of several adhesion molecules as well as low levels of several antigens indicative of activation. These features suggest to Peter Beverley that memory T cells may be more readily activated and that memory may be maintained by crossreactive restimulation.