HDAC6 orchestrates NK cell maturation and antitumor immunity

Area of Science:

• Immunology
• Cell Biology
• Cancer Research

Background:

• Natural killer (NK) cells are crucial for early host defense and tumor surveillance.
• The precise role of specific histone deacetylase (HDAC) members in NK cell regulation is not fully understood.
• Previous studies suggest HDAC inhibition can negatively impact NK cell functions.

Purpose of the Study:

• To investigate the role of HDAC6 in NK cell biology.
• To elucidate the mechanisms by which HDAC6 influences NK cell maturation and effector functions.
• To assess the therapeutic potential of targeting HDAC6 for cancer immunotherapy.

Main Methods:

• Analysis of HDAC family member expression in activated and tumor-infiltrating NK cells.
• Genetic manipulation of HDAC6 (knockout, knockdown, overexpression) to assess its impact on NK cell functions.
• Mechanistic studies on protein acetylation, HSP90 chaperone activity, and IL-15/STAT5 signaling.
• In vivo evaluation using NK cell adoptive transfer and combination therapy with IL-15.

Main Results:

• HDAC6 expression is upregulated upon NK cell activation but decreased in tumor-infiltrating NK cells, correlating with poor survival.
• Hdac6 deficiency impairs NK cell proliferation, maturation, and effector functions; Hdac6 overexpression promotes these functions.
• Loss of HDAC6 leads to HSP90 hyperacetylation, reduced chaperone activity for STAT5, and impaired IL-15 signaling.
• HDAC6 overexpression enhances NK cell-mediated tumor suppression and synergizes with IL-15 therapy.

Conclusions:

• HDAC6 is a critical regulator of NK cell biology, primarily by reinforcing the IL-15/STAT5 pathway.
• HDAC6 represents a promising therapeutic target for enhancing NK cell-based cancer immunotherapy.