An HLA-restricted, p53 specific immune response from HLA transgenic p53 knockout mice.
BACKGROUND
p53 is over-expressed in most human malignancies and is therefore an attractive target for immunotherapy. Unfortunately, a human cytotoxic T cell response to p53 is difficult to generate. p53 knockout transgenic mice may provide a model to circumvent immunologic tolerance to p53 and develop high-affinity p53-specific cytotoxic T lymphocytes (CTL).


METHODS
p53 knockout, HLA A2.1 transgenic mice were generated and immunized with the immunodominant wild-type p53 nonamer peptide epitope p53149-157. Two weeks later splenocytes were harvested and stimulated in vitro with acid-treated, p53 peptide-pulsed syngeneic blast cells. Cultures were restimulated weekly with acid-treated, p53 peptide-pulsed Jurkat cells transfected with the HLA A2.1 gene. Peptide-specific cytotoxic activity was measured by chromium release assay, and the resulting CD8+ effectors were cloned via limiting dilution.


RESULTS
P53 peptide-specific CTL were generated against p53149-157. Clones generated from the p53149-157 cell line demonstrated high affinity and specificity for p53149-157 when presented by HLA A2.1+ antigen-presenting cells. The p53149-157 CTL killed only cells overexpressing p53 cells that were HLA A2.1+ and did not kill cells with normal levels of p53 expression or those that were HLA A2.1-.


CONCLUSIONS
HLA transgenic mice not previously exposed to the p53 protein provide a useful model for generating high-affinity p53-specific CTL.
McCarty
T M
TM
Department of Surgery, City of Hope National Medical Center, Duarte, CA 91010, USA.
Yu
Z
Z
Liu
X
X
Diamond
D J
DJ
Ellenhorn
J D
JD
D000818:Animals; D016827:CD8 Antigens / Q000276:immunology*; D018929:Cell Culture Techniques; D005260:Female; D016158:Genes, p53 / Q000235:genetics* / Q000276:immunology*; D015234:HLA-A Antigens / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D016827:CD8 Antigens; D015234:HLA-A Antigens