INVOLVEMENT OF PEPTIDE ANTIGENS IN THE CYTOTOXICITY BETWEEN 70-KDA HEAT-SHOCK COGNATE PROTEIN-LIKE MOLECULE AND CD3-, CD8-, TCR-ALPHA-BETA(-) KILLER T-CELLS(, CD4)
S. Takashima et al., INVOLVEMENT OF PEPTIDE ANTIGENS IN THE CYTOTOXICITY BETWEEN 70-KDA HEAT-SHOCK COGNATE PROTEIN-LIKE MOLECULE AND CD3-, CD8-, TCR-ALPHA-BETA(-) KILLER T-CELLS(, CD4), The Journal of immunology, 157(8), 1996, pp. 3391-3395
We previously reported that the 70-kDa heat shock cognate protein-like
molecule (hsc70) is expressed on the cell surface along with the neop
lastic transformation of rat fibroblast and that this molecule is reco
gnized by CD3(+), CD4(-), CD8(-), NKR-P1(-), and TCR-alpha beta(-) T (
DNT) killer cells in an MHC class I-unrestricted fashion. We investiga
ted the mechanism of interaction between hsc70 and DNT cells, H-ras on
cogene-transformed rat fibrosarcoma W31 cells expressed hsc70 on the c
ell surface in almost the same density when the cells were growing in
a conventional 5% FCS (5%W31) as when the cell growth was inhibited in
the cultivation with 1% FCS (1%W31), However, DNT cells lysed only 5%
W31, but not 1%W31, Since these observations suggest that certain pept
ide Ags of the fast growing W31 cells may play a role in the interacti
on between hsc70 and DNT cells, we pulsed 1%W31 cells with trifluoroac
etic acid (TFA)-extracted fast growing W31 tumor Ags of less than 3000
Da in molecular size, We also pulsed 1%W31 with TFA-extracted Ags fro
m moderate growing W14 tumors and whole fetus tissues, Our data indica
ted that DNT cells were clearly cytotoxic to 1%W31 pulsed only with TF
A-extracted Ags from W31 tumors, Anti-rat hsc70 mAb completely blocked
this cytotoxicity, In addition, pronase K treatment of Ags clearly in
hibited the cytotoxicity by DNT cells. Taken together, these data sugg
est that the complex of peptide Ag and hsc70 is involved in the cytoto
xic mechanism between hsc70 and DNT cells.