TY - JOUR
T1 - Generation of anti-allogeneic cytotoxic T lymphocytes depends upon a signal, not delivered by tumor cells, that can be provided in trans in the presence of exogenous interleukin-2
AU - Zier, Karen S.
AU - Salvadori, Silvia
PY - 1999
Y1 - 1999
N2 - We have reported that, while immune responses were generated initially against CMS5 tumor cells, they were lost with time. In the present work, we asked whether the tumor cells contributed to this by delivering an inhibitory signal or whether a positive signal, delivered in the form of tumor-derived interleukin-2 (IL-2) or the presence of professional antigen-presenting cells (APC) would be sufficient to enable a sustained response. We observed that the presence of tumor cells did not inhibit the generation of anti-(class I) cytotoxic T lymphocytes (CTL), suggesting that the tumor cells were not directly suppressive. In addition, the lack of a response could not be attributed to insufficient levels of IL-2 alone, since even tumor cells that secreted IL-2 failed to stimulate anti-(class I) CTL. Finally, we observed that professional APC were necessary to deliver an essential signal, but only in the presence of IL-2-secreting tumor cells. Thus, CMS5 cells failed to provide essential signals necessary for CTL generation, but were not directly suppressive.
AB - We have reported that, while immune responses were generated initially against CMS5 tumor cells, they were lost with time. In the present work, we asked whether the tumor cells contributed to this by delivering an inhibitory signal or whether a positive signal, delivered in the form of tumor-derived interleukin-2 (IL-2) or the presence of professional antigen-presenting cells (APC) would be sufficient to enable a sustained response. We observed that the presence of tumor cells did not inhibit the generation of anti-(class I) cytotoxic T lymphocytes (CTL), suggesting that the tumor cells were not directly suppressive. In addition, the lack of a response could not be attributed to insufficient levels of IL-2 alone, since even tumor cells that secreted IL-2 failed to stimulate anti-(class I) CTL. Finally, we observed that professional APC were necessary to deliver an essential signal, but only in the presence of IL-2-secreting tumor cells. Thus, CMS5 cells failed to provide essential signals necessary for CTL generation, but were not directly suppressive.
KW - CTL
KW - IL-2
KW - Suppression
KW - Tumor
UR - http://www.scopus.com/inward/record.url?scp=0032785464&partnerID=8YFLogxK
U2 - 10.1007/s002620050572
DO - 10.1007/s002620050572
M3 - Article
C2 - 10478641
AN - SCOPUS:0032785464
SN - 0340-7004
VL - 48
SP - 247
EP - 252
JO - Cancer Immunology, Immunotherapy
JF - Cancer Immunology, Immunotherapy
IS - 5
ER -