Ox40 regulates the conversion and suppressive function of double-negative regulatory T cells

Area of Science:

• Immunology
• Cellular Biology

Background:

• Naïve CD4 T cells can differentiate into double-negative regulatory T cells (DNT) with stimulation from mature dendritic cells (mDCs) and IL-2.
• IL-2 is known to enhance DNT proliferation and Perforin expression.
• The specific molecular regulators of DNT conversion remain incompletely understood.

Purpose of the Study:

• To investigate the role of Ox40 in the conversion and function of DNT in vitro and in vivo, independent of IL-2 stimulation.
• To elucidate the molecular mechanisms by which Ox40 influences DNT regulatory functions.

Main Methods:

• Utilized an Ox40 agonist (OX86) to study DNT conversion and function.
• Examined DNT conversion and suppressive function in Ox40-deficient models.
• Analyzed gene expression related to proliferation, apoptosis, and immune suppression (Perforin, Granzyme B, Fas ligand, Cxcr3, Cd160, Cd30).

Main Results:

• An Ox40 agonist (OX86) enhanced DNT conversion rates but did not improve suppressive function.
• Ox40 deficiency significantly decreased DNT conversion rates and suppressive function.
• Ox40's influence on DNT suppression was independent of Perforin, Granzyme B, and Fas ligand, affecting proliferation and apoptosis.
• Ox40 deficiency modulated DNT regulatory functions via signals including Cxcr3, Cd160, and Cd30.

Conclusions:

• Ox40 plays a crucial role in promoting the conversion and maintenance of DNT cells.
• Ox40 deficiency impairs DNT regulatory capacity by influencing proliferation, apoptosis, and the expression of key regulatory genes.