Unknown

Dataset Information

0

CCL22-specific T Cells: Modulating the immunosuppressive tumor microenvironment.


ABSTRACT: Tumor cells and tumor-infiltrating macrophages produce the chemokine CCL22, which attracts regulatory T cells (Tregs) into the tumor microenvironment, decreasing anticancer immunity. Here, we investigated the possibility of targeting CCL22-expressing cells by activating specific T cells. We analyzed the CCL22 protein signal sequence, identifying a human leukocyte antigen A2- (HLA-A2-) restricted peptide epitope, which we then used to stimulate peripheral blood mononuclear cells (PMBCs) to expand populations of CCL22-specific T cells in vitro. T cells recognizing an epitope derived from the signal-peptide of CCL22 will recognize CCL22-expressing cells even though CCL22 is secreted out of the cell. CCL22-specific T cells recognized and killed CCL22-expressing cancer cells. Furthermore, CCL22-specific T cells lysed acute monocytic leukemia cells in a CCL22 expression-dependent manner. Using the Enzyme-Linked ImmunoSPOT assay, we examined peripheral blood mononuclear cells from HLA-A2+ cancer patients and healthy volunteers for reactivity against the CCL22-derived T-cell epitope. This revealed spontaneous T-cell responses against the CCL22-derived epitope in cancer patients and in healthy donors. Finally, we performed tetramer enrichment/depletion experiments to examine the impact of HLA-A2-restricted CCL22-specific T cells on CCL22 levels among PMBCs. The addition or activation of CCL22-specific T cells decreased the CCL22 level in the microenvironment. Activating CCL22-specific T cells (e.g., by vaccination) may directly target cancer cells and tumor-associated macrophages, thereby modulating Treg recruitment into the tumor environment and augmenting anticancer immunity.

SUBMITTER: Martinenaite E 

PROVIDER: S-EPMC5139648 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

altmetric image

Publications


Tumor cells and tumor-infiltrating macrophages produce the chemokine CCL22, which attracts regulatory T cells (Tregs) into the tumor microenvironment, decreasing anticancer immunity. Here, we investigated the possibility of targeting CCL22-expressing cells by activating specific T cells. We analyzed the CCL22 protein signal sequence, identifying a human leukocyte antigen A2- (HLA-A2-) restricted peptide epitope, which we then used to stimulate peripheral blood mononuclear cells (PMBCs) to expand  ...[more]

Similar Datasets

| S-EPMC9475452 | biostudies-literature
| S-EPMC9465322 | biostudies-literature
| S-EPMC7714985 | biostudies-literature
| S-EPMC9900325 | biostudies-literature
| S-EPMC5834266 | biostudies-literature
| S-EPMC6549513 | biostudies-literature
| S-EPMC8122391 | biostudies-literature
| S-EPMC8114109 | biostudies-literature
| S-EPMC9547238 | biostudies-literature
| S-EPMC5825917 | biostudies-other