Rexinoids Modulate Effector T Cell Expression of Mucosal Homing Markers CCR9 and α4β7 Integrin and Direct Their...

Area of Science:

• Immunology
• Pharmacology
• Molecular Biology

Background:

• Altering T cell trafficking to mucosal sites can improve immune responses against infections and cancers.
• All-trans-retinoic acid (ATRA) promotes T cell mucosal homing via retinoic acid receptors (RARs) and retinoid X receptors (RXRs).
• ATRA's instability and toxicity limit its clinical application, necessitating safer alternatives.

Purpose of the Study:

• To investigate novel rexinoids as potential alternatives or adjuncts to ATRA for enhancing T cell mucosal homing.
• To evaluate rexinoids' ability to mimic ATRA's effects on T cell migration.
• To assess the synergistic potential of rexinoids with ATRA.

Main Methods:

• In vitro studies using novel rexinoids and T cells.
• Assessing expression of mucosal-homing receptors CCR9 and α4β7.
• Measuring T cell migration towards CCL25 in response to rexinoids, with or without ATRA.

Main Results:

• Select rexinoids increased CCR9 and α4β7 expression and enhanced T cell migration to CCL25 independently of ATRA.
• Other rexinoids demonstrated synergistic effects with ATRA, boosting CCR9 expression and migration at suboptimal doses.
• Rexinoids effectively promoted T cell mucosal homing in vitro.

Conclusions:

• Rexinoids can serve as effective ATRA mimics or potentiators for promoting T cell mucosal homing.
• These findings support the potential clinical use of rexinoids in immunotherapies for mucosal infections and cancers.
• Rexinoids represent a promising, safer alternative to ATRA for enhancing mucosal immunity.