Ej. Usherwood et al., Functionally heterogeneous CD8(+) T-cell memory is induced by Sendai virusinfection of mice, J VIROLOGY, 73(9), 1999, pp. 7278-7286
It has recently been established that memory CD8(+) T cells induced by vira
l infection are maintained at unexpectedly high frequencies in the spleen.
While it has been established that these memory cells are phenotypically he
terogeneous, relatively little is known about the functional status of thes
e cells. Here we investigated the proliferative potential of CD8(+) memory
T cells induced by Sendai virus infection. High frequencies of CD8(+) T cel
ls specific for both dominant and subdominant Sendai virus epitopes persist
ed for many weeks after primary infection, and these cells were heterogeneo
us with respect to CD62L expression (approximately 20% CD62L(hi) and 80% CD
62L(lo)). Reactivation of these cells with the antigenic peptide in vitro i
nduced strong proliferation of antigen-specific CD8(+) T cells. However, ap
proximately 20% of the cells failed to proliferate in vitro in response to
a cognate peptide but nevertheless differentiated into effector cells and a
cquired full cytotoxic potential. These cells also expressed high levels of
CD62L (in marked contrast to the CD62L(lo) status of the proliferating cel
ls in the culture). Direct isolation of CD62L(hi) and CD62L(lo) CD8(+) T ce
lls from memory mice confirmed the correlation of this marker with prolifer
ative potential. Taken together, these data demonstrate that Sendai virus i
nfection induces high frequencies of memory CD8(+) T cells that are highly
heterogeneous in terms of both their phenotype and their proliferative pote
ntial.