VEGFR2 activity on myeloid cells mediates immune suppression in the tumor microenvironment

Area of Science:

• Oncology
• Immunology
• Molecular Biology

Background:

• Angiogenesis, driven by vascular endothelial growth factor-A (VEGF), is crucial for cancer growth.
• VEGF signaling is increasingly recognized for its role in cancer-related immune suppression.
• Combining anti-VEGF therapy with immunotherapy is a promising strategy, but underlying mechanisms require elucidation.

Purpose of the Study:

• To investigate the function of VEGFR2+ myeloid cells in regulating tumor immunity.
• To elucidate the mechanisms by which anti-VEGF strategies enhance cancer immunotherapy.
• To determine how VEGF blockade impacts the immunosuppressive phenotype of myeloid cells and T cell activation.

Main Methods:

• Utilized preclinical cancer models to study myeloid cell function.
• Analyzed VEGFR2 expression on tumor-associated myeloid cells.
• Assessed the effects of VEGF blockade on myeloid cell phenotype, T cell activation, and immune checkpoint blockade efficacy.

Main Results:

• VEGF induces an immunosuppressive phenotype in VEGFR2+ myeloid cells, including upregulation of programmed cell death 1 ligand 1.
• VEGF blockade effectively inhibits this immunosuppressive phenotype.
• VEGF inhibition leads to increased T cell activation and potentiates the efficacy of immune checkpoint blockade.

Conclusions:

• VEGF signaling through VEGFR2 on myeloid cells plays a critical role in tumor immune suppression.
• Targeting VEGF is a viable strategy to enhance the effectiveness of cancer immunotherapy, particularly immune checkpoint blockade.
• This study provides mechanistic insights into the synergistic effects of combining anti-VEGF and immune therapies.