ILC2s amplify PD-1 blockade by activating tissue-specific cancer immunity

Area of Science:

• Immunology
• Oncology
• Cell Biology

Background:

• Group 2 innate lymphoid cells (ILC2s) are key regulators of tissue immunity.
• The role of ILC2s in cancer immunity and immunotherapy remains largely undefined.
• ILC2s have been observed in various tumor tissues, including pancreatic cancer.

Purpose of the Study:

• To investigate the function of ILC2s in pancreatic ductal adenocarcinoma (PDAC) immunity.
• To determine if ILC2s can be therapeutically targeted to enhance anti-PD-1 immunotherapy.
• To explore the presence and role of ILC2s in human PDAC.

Main Methods:

• Analysis of ILC2 infiltration and activation in mouse models of PDAC.
• Investigation of the effects of Interleukin-33 (IL33) on tumor-infiltrating ILC2s (TILC2s) and CD8+ T cells.
• Assessment of PD-1 expression on TILC2s and the impact of PD-1 blockade on anti-tumor immunity.
• Examination of PD-1+ TILC2s and T cells in human PDAC samples.

Main Results:

• ILC2s infiltrate PDAC and activate tissue-specific anti-tumor immunity.
• IL33 activates TILC2s and CD8+ T cells in pancreatic tumors, restricting tumor growth.
• TILC2s express the inhibitory receptor PD-1, and PD-1 blockade expands TILC2s and enhances anti-tumor immunity.
• PD-1+ TILC2s and T cells are prevalent in human PDAC, suggesting shared therapeutic targets.

Conclusions:

• ILC2s act as anti-cancer immune cells in PDAC and are potential targets for immunotherapy.
• ILC2s function as tissue-specific enhancers of cancer immunity, amplifying anti-PD-1 therapy efficacy.
• Targeting both ILC2s and T cells may represent a broadly applicable immunotherapeutic strategy for various cancers.