C-type lectin domain family 9 member A and X-C motif chemokine receptor 1 (CLEC9A and XCR1)

CLEC9A (C-type lectin domain family 9 member A) and XCR1 (X-C motif chemokine receptor 1) are highly specific surface receptors that define the conventional type 1 dendritic cell (cDC1) subset in both humans and mice (2.2.1, 2.3.1). CLEC9A functions as a specialized endocytic receptor that recognizes F-actin exposed on necrotic cells, facilitating the capture and cross-presentation of dead-cell-associated antigens to CD8+ T cells (2.1.3, 2.2.3). XCR1 is a G protein-coupled receptor that binds the chemokine XCL1, mediating the migration of cDC1s toward activated T cells and natural killer (NK) cells, which is essential for the spatial coordination of anti-tumor and anti-viral immune responses (2.2.3, 3.3.5). Because cDC1s are the most potent cells for priming cytotoxic T lymphocytes (CTLs), CLEC9A and XCR1 are prime targets for cancer vaccines and immunotherapies designed to deliver antigens or adjuvants directly to this cell population (2.2.1, 3.2.3). Therapeutic strategies include antibody-antigen fusion proteins (e.g., anti-CLEC9A-NY-ESO-1) and cytokine-antibody fusions (e.g., XCR1Ab-IFNmut) aimed at enhancing tumor immunogenicity (2.5.1, 3.2.5). While promising, challenges such as the development of anti-drug antibodies (ADA) and the need for specific adjuvants to ensure activation rather than tolerance remain significant hurdles in clinical development (2.5.1, 3.2.1).

Other names

DNGR-1CD370C-type lectin domain containing 9AHEEE9341UNQ9341GPR5CCXCR1Lymphotactin receptorCPXCR1Dendritic cell natural killer lectin group receptor 1

Targeted delivery of tumor-associated antigens or immunostimulatory agents (such as interferon) directly to conventional type 1 dendritic cells (cDC1s) to enhance antigen cross-presentation and prime robust cytotoxic T lymphocyte (CTL) responses.