HIF-2α is indispensable for regulatory T cell function.

Area of Science:

• Immunology
• Cellular Biology
• Molecular Biology

Background:

• Hypoxia-inducible factors (HIFs) regulate cellular responses to low oxygen.
• The specific roles of HIF-1α and HIF-2α in regulatory T (Treg) cells remain unclear.
• Treg cells are critical for immune homeostasis and preventing autoimmunity.

Purpose of the Study:

• To investigate the distinct functions of HIF-1α and HIF-2α in Treg cells.
• To explore the therapeutic potential of targeting HIFs in Treg-mediated diseases.
• To elucidate the regulatory relationship between HIF-1α and HIF-2α within Treg cells.

Main Methods:

• Foxp3-specific knockout mouse models for HIF-1α and HIF-2α.
• Assessment of Treg cell development and function in vitro and in vivo.
• Analysis of Treg cell reprogramming into IL-17-secreting cells.
• Evaluation of tumor growth and metastasis in KO mouse models.

Main Results:

• Treg cell development is unaffected by HIF-1α or HIF-2α knockout.
• HIF-2α knockout Treg cells exhibit impaired suppression of colitis and airway hypersensitivity.
• HIF-2α knockout Treg cells show increased reprogramming to IL-17-producing cells.
• HIF-2α represses HIF-1α expression; HIF-1α upregulation in HIF-2α KO Treg cells.
• Loss of HIF-2α in Treg cells confers resistance to tumor growth and metastasis.

Conclusions:

• HIF-2α, but not HIF-1α, is essential for Treg cell suppressive function.
• Targeting HIF-2α destabilizes Treg cells, impacting immune responses.
• HIF-2α inhibition in Treg cells presents a potential strategy for cancer therapy and immune modulation.