CD1b Tetramers Identify T Cells that Recognize Natural and Synthetic Diacylated Sulfoglycolipids from Mycobacterium tuberculosis. Issue 4 (19th April 2018) - James, Charlotte A.
Summary: Mycobacterial cell wall lipids bind the conserved CD1 family of antigen-presenting molecules and activate T cells via their T cell receptors (TCRs). Sulfoglycolipids (SGLs) are uniquely synthesized by Mycobacterium tuberculosis, but tools to study SGL-specific T cells in humans are lacking. We designed a novel hybrid synthesis of a naturally occurring SGL, generated CD1b tetramers loaded with natural or synthetic SGL analogs, and studied the molecular requirements for TCR binding and T cell activation. Two T cell lines derived using natural SGLs are activated by synthetic analogs independently of lipid chain length and hydroxylation, but differentially by saturation status. By contrast, two T cell lines derived using an unsaturated SGL synthetic analog were not activated by the natural antigen. Our data provide a bioequivalence hierarchy of synthetic SGL analogs and SGL-loaded CD1b tetramers. These reagents can now be applied to large-scale translational studies investigating the diagnostic potential of SGL-specific T cell responses or SGL-based vaccines. Graphical Abstract: Highlights: We describe hybrid synthesis of a mycobacterial sulfoglycolipid T cell antigen This sulfoglycolipid (SGL) analog is bioequivalent to the natural compound This antigen was used to generate SGL-loaded CD1b tetramers Tetramers can be used to identify SGL-specific T cells in peripheral blood Abstract : Sulfoglycolipids (SGLs) are uniquely synthesized by Mycobacterium tuberculosis (Mtb) and recognized by human T cells. James, Yu et al. describe a new hybrid synthesis for key antigenic determinants of SGLs and the development of SGL-specific tetramers that can now be applied to large-scale translational studies.