The protective effect of CD8+ T cells was demonstrated in T.gondii infected mice in experiments also involving adoptive transfer40, 41, 42 or depletion43 of this lymphocyte population.Interestingly, previous in vivo observations showed that infection with N.caninum was able to protect against lethal T. gondii infection by theinduction of CD8+ T cells immunoreactive to both parasites33. Here, CD8A is linked to infection.