7., the use of two different re-challenge protocols can differentiate between basic determinants required for CD8+TM recall responses in the wake of an “acute” LCMV Arm infection (AT/RC Arm) and a more complex constellation of mechanisms supporting the effective coordination IIo CD8+TE expansions after a “chronic” LCMV clone 13 infection (AT/RC cl13) (Fig 1A). Here, CD8A is linked to infection.