Tumor progression can occur despite the induction of very high levels of self/tumor antigen-specific CD8+ T cells in patients with melanoma.
The identification of many tumor-associated epitopes as nonmutated "self" Ags led to the hypothesis that the induction of large numbers of self/tumor Ag-specific T cells would be prevented because of central and peripheral tolerance. We report in this study on vaccination efforts in 95 HLA-A*0201 patients at high risk for recurrence of malignant melanoma who received prolonged immunization with the "anchor-modified" synthetic peptide, gp100209-217(210M). Vaccination using this altered peptide immunogen was highly effective at inducing large numbers of self/tumor-Ag reactive T cells in virtually every patient tested, with levels as high as 42% of all CD8+ T cells assessed by tetramer analysis. From 1 to 10% of all CD8+ cells were tumor-Ag reactive in 44% of patients and levels >10% were generated in 17% of patients. These studies were substantiated using the ELISPOT assay and a bulk cytokine release assay. Although our data regarding "tumor escape" were inconclusive, some patients had growing tumors that expressed Ag and HLA-A*0201 in the presence of high levels of antitumor T cells. There was no difference in the levels of antitumor Ag-specific T cells in patients who recurred compared with those that remained disease-free. Thus, the mere presence of profoundly expanded numbers of vaccine-induced, self/tumor Ag-specific T cells cannot by themselves be used as a "surrogate marker" for vaccine efficacy. Further, the induction of even high levels of antitumor T cells may be insufficient to alter tumor progression.
Rosenberg
Steven A
SA
Surgery Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. sar@nih.gov
Sherry
Richard M
RM
Morton
Kathleen E
KE
Scharfman
William J
WJ
Yang
James C
JC
Topalian
Suzanne L
SL
Royal
Richard E
RE
Kammula
Udai
U
Restifo
Nicholas P
NP
Hughes
Marybeth S
MS
Schwartzentruber
Douglas
D
Berman
David M
DM
Schwarz
Susan L
SL
Ngo
Lien T
LT
Mavroukakis
Sharon A
SA
White
Donald E
DE
Steinberg
Seth M
SM
D000328:Adult; D000368:Aged; D000951:Antigens, Neoplasm / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D019496:Cancer Vaccines / Q000276:immunology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007114:Immunization; D008297:Male; D008545:Melanoma / Q000276:immunology* / Q000401:mortality / Q000628:therapy; D008562:Membrane Glycoproteins / Q000276:immunology*; D008875:Middle Aged; D010446:Peptide Fragments / Q000276:immunology*; D012878:Skin Neoplasms / Q000276:immunology* / Q000401:mortality / Q000628:therapy; D058951:gp100 Melanoma Antigen
D000951:Antigens, Neoplasm; D001324:Autoantigens; D019496:Cancer Vaccines; D008562:Membrane Glycoproteins; C548637:PMEL protein, human; D010446:Peptide Fragments; D058951:gp100 Melanoma Antigen