T. Hisatsune et al., CD8(-CELLS SPECIFIC TO THE EXOGENOUS ANTIGEN - MODE OF ANTIGEN RECOGNITION AND POSSIBLE IMPLICATION IN IMMUNOSUPPRESSION() T), The Journal of immunology, 154(1), 1995, pp. 88-96
This study demonstrates and characterizes CD8(+) T cells specific to t
he exogenous Ag, bovine alpha s1-casein. Purified CD8(+) T cells from
alpha s1-casein-primed lymph node cells proliferated well in response
to an asl-casein derivative, trypsin-digested alpha s1 -casein. CD8(+)
T cell repertoire for the exogenous Ag was directly demonstrated in t
he primary culture condition. The intact asl -casein primed the respon
ding CD8(+) T cells in vivo more efficiently than the tryptic alpha s1
-casein; however, the in vitro proliferative response by the intact al
pha s1-casein was weaker than that of the tryptic alpha s1-casein. CD8
(+) T cells recognized the exogenous Ag in association with MHC class
I molecules as revealed by an Ab-blocking study. The major immunodomin
ant region for the CD8(+) T cells was mapped to region 136-151 of alph
a s1-casein, and peptide 136-151 primed the responding CD8(+) T cells
but not any CD4(+) T cells. Peptide 136-151 is the CD8(+) T cell-speci
fic determinant. Upon antigenic stimulation, the exogenous Ag-specific
CD8(+) T cells produced a significant level of IFN-gamma, which has i
mmune suppressive activity for IgE synthesis. Our study strongly impli
es that CD8(+) T cells that proliferate and produce IFN-gamma in respo
nse to the exogenous Ag would play a vital role in Ag-specific immunos
uppression.