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Updated: Aug 9, 2026
A Method For Production of Recombinant mCD1d Protein in Insect Cells.
Published on: December 11, 2007
Biochemical characterization of CD1d expression in the absence of beta2-microglobulin
1Division of Gastroenterology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
Insights
CD1d molecules can reach the cell surface without beta2-microglobulin (beta2m). However, the absence of beta2m alters CD1d glycosylation, indicating an immature form.
Area of Science:
- Immunology
- Molecular Biology
- Cell Biology
Background:
- CD1d is a major histocompatibility complex class I-like molecule.
- It presents hydrophobic antigens to T cells via a unique pathway.
- CD1d expression on intestinal epithelial cells is independent of beta2-microglobulin (beta2m).
Purpose of the Study:
- To define the relationship between CD1d and beta2m.
- To characterize the biochemical structure of CD1d in the absence of beta2m.
Main Methods:
- Utilized CD1d transfectants and CD1d-specific antibodies.
- Performed endoglycosidase-H and N-glycanase digestion.
- Conducted pulse-chase metabolic labeling studies.
Main Results:
- In the absence of beta2m, CD1d is a 45-kDa cell-surface glycoprotein sensitive to endoglycosidase-H.
- With beta2m, CD1d is a 48-kDa cell-surface glycoprotein resistant to endoglycosidase-H.
- Beta2m is required for acquiring endoglycosidase-H resistance, indicating proper maturation.
Conclusions:
- CD1d can be transported to the cell surface independently of beta2m.
- The absence of beta2m leads to altered glycosylation of CD1d, consistent with an immature glycoprotein.
- Beta2m influences the post-translational modification and maturation of CD1d.
Abstract:
CD1d is a major histocompatibility complex class I-like molecule that exhibits a distinct antigen processing pathway that functions in the presentation of hydrophobic antigens to T cells. CD1d has been previously shown to be expressed on the cell surface of human intestinal epithelial cell lines in vivo and a transfected cell line in vitro independently of beta2-microglobulin (beta2m). To define the relationship between CD1d and beta2m and characterize the biochemical structure of CD1d in the absence of beta2m, we have used a newly generated series of CD1d transfectants and CD1d-specific antibodies. These studies show that in the absence of beta2m, CD1d is expressed on the cell surface as a 45-kDa glycoprotein that is sensitive to endoglycosidase-H and is reduced to 37-kDa after N-glycanase digestion. In contrast, in the presence of beta2m, CD1d is expressed on the cell surface as a 48-kDa endoglycosidase-H-resistant glycoprotein. Pulse-chase metabolic labeling studies demonstrate that acquisition of endoglycosidase-H resistance of CD1d is observed in the presence of beta2m but not in the absence of beta2m even after a 24-h chase period. Thus, CD1d is able to be transported to the cell surface independently of beta2m; however, in the absence of beta2m, the glycosylation pattern of CD1d is altered and consistent with an immature glycoprotein.
