To demonstrate proof of concept for this strategy, we have initiated studies to identify immunogenic T cell epitopes for mutated tumor antigens, such as K-ras which expressed by several GI cancers. A library of overlapping 9mer and 10mer peptides which span the amino acid mutation has been synthesized and we are currently performing T cell stimulations with PBL of a variety of HLA types to determine the immunogenicity of the peptides and their MHC restriction in patients whose tumors possess k-ras mutations. In contrast to low throughput screening which require several rounds of in vitro sensitization to evaluate each peptide, our current approach will screen hundreds of individual T cell cultures one week after peptide stimulation. A significant aspect of this project is to apply automated instrumentation for high throughput T cell stimulation and screening in a 384 well format. Further refinements include the comparative evaluation of computer based algorithms that predict the immunogenicity and potential proteosomal cleavage sites for the putative epitopes. This in silico screening would complement our high throughput functional screening of epitopes.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Investigator-Initiated Intramural Research Projects (ZIA)
Project #
1ZIABC010649-09
Application #
8763162
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
9
Fiscal Year
2013
Total Cost
$205,980
Indirect Cost
Name
National Cancer Institute Division of Basic Sciences
Department
Type
DUNS #
City
State
Country
Zip Code
Bartlett, Edmund K; Fetsch, Patricia A; Filie, Armando C et al. (2014) Human melanoma metastases demonstrate nonstochastic site-specific antigen heterogeneity that correlates with T-cell infiltration. Clin Cancer Res 20:2607-16