Differential gene expression profiles in a human T-cell line stimulated with a tumor-associated self-peptide versus an enhancer agonist peptide.
OBJECTIVE
Previous studies have shown that a specific 9-mer amino acid epitope (designated CAP-1) of the human "self" tumor-associated carcinoembryonic antigen can be used to stimulate CD8+ T cells from peripheral blood mononuclear cells of carcinoma patients vaccinated with pox vector-based carcinoembryonic antigen vaccines. A T-cell receptor agonist epitope of CAP-1 (designated CAP1-6D) has been shown to enhance the stimulation of T cells over levels obtained using CAP-1. The purpose of this study was to analyze gene expression profiles in T cells stimulated with the native CAP-1 versus the agonist CAP1-6D peptide.


METHODS
Microarray analyses were conducted to analyze differential gene expression profiles of a T-cell line stimulated with native versus agonist peptides.


RESULTS
Numerous genes and gene clusters are identified as differentially expressed as a consequence of stimulation with the agonist peptide versus the native peptide; two genes, however, stand out in magnitude: the chemokine lymphotactin and granzyme B. In particular, lymphotactin expression is >12 times more pronounced in agonist-stimulated T cells. An ELISA assay was developed that confirmed marked lymphotactin secretion in T cells when stimulated with the agonist versus the native peptide. A chemotaxis assay also demonstrated the biological activity of the lymphotactin produced.


CONCLUSIONS
To our knowledge, these are the first studies of gene expression profiles of a defined T-cell line in response to stimulation with a defined antigen. They are also the first to compare, via cDNA microarray, responses of a T-cell line to (a) a tumor-associated self-antigen and (b) a native epitope versus an agonist epitope.
Palena
Claudia
C
Laboratory of Tumor Immunology and Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland 20892, USA.
Schlom
Jeffrey
J
Tsang
Kwong-Yok
KY
D000951:Antigens, Neoplasm / Q000235:genetics / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002272:Carcinoembryonic Antigen / Q000737:chemistry / Q000276:immunology*; D019744:Chemokines, C; D003110:Colonic Neoplasms / Q000276:immunology / Q000378:metabolism* / Q000556:secondary; D004797:Enzyme-Linked Immunosorbent Assay; D018984:Epitopes, T-Lymphocyte / Q000276:immunology / Q000378:metabolism; D020869:Gene Expression Profiling; D006801:Humans; D008222:Lymphokines; D020411:Oligonucleotide Array Sequence Analysis; D010446:Peptide Fragments / Q000276:immunology / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism; D014407:Tumor Cells, Cultured
D000951:Antigens, Neoplasm; D002272:Carcinoembryonic Antigen; D019744:Chemokines, C; D018984:Epitopes, T-Lymphocyte; D008222:Lymphokines; D010446:Peptide Fragments; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D012795:Sialoglycoproteins; C092390:XCL1 protein, human; C018997:lymphotactin