STRUCTURAL REQUIREMENTS FOR GLYCOLIPID ANTIGEN RECOGNITION BY CD1B-RESTRICTED T-CELLS

The human CD1b protein presents lipid antigens to T cells, but the mol ecular mechanism is unknown. Identification of mycobacterial glucose m onomycolate (GMM) as a CD1b-presented glycolipid allowed determination of the structural requirements for its recognition by T cells. Presen tation of GMM to CD1b-restricted T cells was not affected by substanti al variations in its lipid tails, but was extremely sensitive to chemi cal alterations in its carbohydrate or other polar substituents. These findings support the view that the recently demonstrated hydrophobic CD1 groove binds the acyl chains of lipid antigens relatively nonspeci fically, thereby positioning the hydrophilic components for highly spe cific interactions with T cell antigen receptors.