HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Geho, D. H. Articles by Tykocinski, M. L. Search for Related Content PubMed PubMed Citation Articles by Geho, D. H. Articles by Tykocinski, M. L. Pubmed/NCBI databases Substance via MeSH

Glycosyl-Phosphatidylinositol Reanchoring Unmasks Distinct Antigen-Presenting Pathways for CD1b and CD1c¹

David H. Geho^*, John D. Fayen^*, Robin M. Jackman^2,, D. Branch Moody, Steven A. Porcelli and Mark L. Tykocinski^3,*,

^* Department of Pathology, Case Western Reserve University, Cleveland, OH 44106; Lymphocyte Biology Section, Division of Rheumatology, Immunology, and Allergy, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115; and Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104

Human CD1 proteins present lipid and glycolipid Ags to T cells. Cellular trafficking patterns of CD1 proteins may determine the ability of differing isoforms of CD1 to acquire, bind, and present these Ags to T cells. To test this hypothesis, glycosyl-phosphatidylinositol (GPI)-modified variants of CD1b and CD1c were engineered by chimerization with a GPI modification signal sequence derived from decay-accelerating factor (DAF). GPI reanchoring was confirmed by demonstrating the phosphatidylinositol-specific phospholipase C sensitivity of the CD1b · DAF and CD1c · DAF fusion proteins expressed on transfectant cell surfaces. Using cytotoxicity and cytokine release assays as functional readouts, we demonstrated that CD1c · DAF is as efficient as native CD1c in presenting mycobacterial Ags to the human CD1c-restricted T cell line CD8-1. In contrast, CD1b · DAF, although also capable of presenting Ag (in this case to the CD1b-restricted T cell line LDN5), was less efficient than its native CD1b counterpart. The data support the idea that CD1c · DAF maintains the capacity to access CD1c Ag-loading compartment(s), whereas CD1b · DAF is diverted by its GPI anchor away from the optimal CD1b Ag-loading compartment(s). This constitutes the first GPI reanchoring of CD1 proteins and provides evidence that CD1b and CD1c have nonoverlapping Ag-presenting pathways, suggesting that these two Ag-presenting molecules may have distinct roles in lipid Ag presentation.

This article has been cited by other articles:

				J. S. Im, K. O. A. Yu, P. A. Illarionov, K. P. LeClair, J. R. Storey, M. W. Kennedy, G. S. Besra, and S. A. Porcelli Direct Measurement of Antigen Binding Properties of CD1 Proteins Using Fluorescent Lipid Probes J. Biol. Chem., January 2, 2004; 279(1): 299 - 310. [Abstract] [Full Text] [PDF]