Multiple defects in antigen presentation and T cell development by mice expressing cytoplasmic tail-truncated CD1d

Area of Science:

• Immunology
• Molecular Biology
• Cell Biology

Background:

• The CD1 family of beta(2)-microglobulin-associated molecules presents lipid antigens.
• Tyrosine-based motifs in the CD1 cytoplasmic tail and invariant chain (Ii) are known to regulate glycoprotein trafficking.
• Intracellular CD1 trafficking and antigen presentation pathways are not fully understood.

Purpose of the Study:

• To investigate the in vivo function of the CD1d cytoplasmic tail tyrosine motif.
• To determine the role of this motif in intracellular trafficking, antigen presentation, and T cell development.

Main Methods:

• Generation of knock-in mice with a deleted CD1d cytoplasmic tail tyrosine motif using homologous recombination in embryonic stem cells.
• Analysis of surface CD1d expression and invariant chain (Ii) presence.
• Assessment of intracellular trafficking, antigen presentation, and T cell development in mutant mice.

Main Results:

• Mutant mice exhibited normal surface CD1d expression and retained invariant chain (Ii).
• Despite normal surface expression, these mice displayed selective abnormalities in intracellular trafficking.
• Significant defects in antigen presentation and T cell development were observed in the mutant mice.

Conclusions:

• The CD1d cytoplasmic tail tyrosine motif plays a critical role in vivo.
• This motif is essential for regulating intracellular trafficking, antigen presentation, and T cell development.
• The findings underscore the importance of specific cytoplasmic tail motifs for CD1d function.