M. Asano et al., AUTOIMMUNE-DISEASE AS A CONSEQUENCE OF DEVELOPMENTAL ABNORMALITY OF AT-CELL SUBPOPULATION, The Journal of experimental medicine, 184(2), 1996, pp. 387-396
Neonatal thymectomy (NTx), especially around day 3 after birth, causes
various organ-specific autoimmune diseases in mice. This report shows
that: (n) T cells expressing the interleukin 2 receptor oc chains (CD
25) ontogenically begin to appear in the normal periphery immediately
after day 3, rapidly increasing within 2 wk to nearly adult levels (si
milar to 10% of CD3(+) cells, especially of CD4(+) cells); (b) NTx on
day 3 eliminates CD25(+) T cells G-om the periphery for several days;
inoculation immediately after NTx of CD25(+) splenic T cells from syng
eneic non-Tx adult mice prevents autoimmune development, whereas inocu
lation of CD25(-) T cells even at a larger dose does not; and furtherm
ore, (c) similar autoimmune diseases can be produced in adult athymic
nu/nu mice by inoculating either spleen cell suspensions from 3-d-old
euthymic nu/+ mice or CD25(+) cell-depleted spleen cell suspensions fr
om older, even l-yr-old, nu/+ mice. The CD25(-) populations from neona
tes or adults are also similar ill the profile of cytokine formation.
These: results, taken together, indicate that one aspect of peripheral
self-tolerance is maintained by CD25(+) T cells that sustain potentia
lly pathogenic self-reactive T cells in a CD25(-) dormant state; the t
hymic production of the former is developmentally programmed to begin
on day 3 after birth in mice. Thus, NTx on day 3 can, at least transie
ntly, eliminate/reduce the autoimmune-preventive CD25(+) T cells, ther
eby leading to activation of the self-reactive T cells that have been
produced before NTx.