Macrophages express multiple ligands for gammadelta TCRs.

Area of Science:

• Immunology
• Cell Biology

Background:

• The ligands recognized by gammadelta T cells are largely unknown, hindering a full understanding of their function.
• Existing knowledge of gammadelta T cell ligands is limited to a few identified molecules.

Purpose of the Study:

• To identify and characterize novel ligands for common mouse gammadelta T cell subsets.
• To investigate the expression patterns and regulation of these newly identified ligands.

Main Methods:

• Utilized soluble multimerized gammadelta T cell receptors (smTCRs) to detect ligands on macrophages.
• Analyzed ligand expression on peritoneal macrophages from untreated and Listeria monocytogenes-infected mice.
• Investigated ligand induction by lipopolysaccharide (LPS) in vitro.

Main Results:

• Identified ligands for two major gammadelta T cell subsets on resident peritoneal macrophages.
• Ligand expression was constitutive in untreated mice and induced by Listeria monocytogenes infection.
• The two ligands differed in abundance, induction kinetics, and response to LPS.
• Ligand expression was independent of beta2-microglobulin, suggesting they are not MHC class I molecules.

Conclusions:

• Discovered novel, host-derived ligands for gammadelta T cells expressed on macrophages.
• These ligands are constitutively present and upregulated by inflammatory stimuli.
• The findings expand the known repertoire of gammadelta T cell ligands and their regulation.