The Expression of Adenosine A2B Receptor on Antigen-Presenting Cells Suppresses CD8⁺ T-cell Responses and Promotes...

Area of Science:

• Immunology
• Cancer Biology
• Pharmacology

Background:

• Adenosine receptor signaling, particularly via A2A and A2B receptors (A2AR/A2BR), plays a role in regulating antitumor immunity.
• While A2AR and A2BR share immunosuppressive functions, the specific role of A2BR in cancer progression remains less understood.

Purpose of the Study:

• To elucidate the distinct role of A2BR in tumor growth, metastasis, and immune response.
• To evaluate the therapeutic potential of A2BR inhibition in cancer treatment.

Main Methods:

• Utilized genetically modified mice with A2BR deletion in specific cell types (hematopoietic, myeloid, CD11c-expressing cells).
• Assessed tumor growth, metastasis, and immune cell infiltration (T cells, myeloid cells, dendritic cells) in vivo.
• Analyzed antigen-presenting cell (APC) function and cross-priming of tumor antigen-specific CD8+ T cells.
• Investigated the efficacy of pharmacologic A2BR blockade in combination with adoptive T-cell therapy.

Main Results:

• A2BR expression on hematopoietic cells significantly promoted tumor growth.
• A2BR deficiency enhanced anticancer T-cell immunity, increasing CD8+ T cell responses.
• A2BR deletion in myeloid or CD11c+ cells delayed primary tumor growth.
• Myeloid-specific A2BR deletion, but not CD11c-specific deletion, delayed lung metastasis.
• Pharmacologic A2BR blockade augmented the antitumor effects of adoptive T-cell therapy.

Conclusions:

• A2BR on myeloid cells and APCs suppresses antitumor CD8+ T cell responses and promotes tumor metastasis.
• Targeting A2BR, particularly on myeloid cells, represents a viable strategy to enhance cancer immunotherapy.
• Combining A2BR inhibition with T-cell-based therapies holds promise for treating cancer growth and metastasis.