| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
* Department of Oncology, Georgetown University Medical Center, Washington, DC 20057; and
Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC 20057
Genetic polymorphisms found in the killer Ig-like receptor (KIR), two domains, long cytoplasmic tail 2/3 (KIR2DL2/3) locus are responsible for the differential binding of KIR2DL2/3 allelic products with their HLA-C ligands and have been associated with the resolution of hepatitis C infection. In our study, a KIR CD3
fusion-binding assay did not detect any interaction between the KIR2DL2*004 extracellular domain and several putative KIR2DL2/3 ligands. To determine the amino acid polymorphism(s) responsible for the KIR2DL2*004 phenotype, we mutated the polymorphic residues of full-length KIR and expressed them in human Jurkat cells. Flow cytometry analysis failed to detect the surface expression of receptors containing a threonine at position 41 (T41), a polymorphism specific to KIR2DL2*004. Confocal microscopy showed that receptors containing T41 were retained inside the cell and had a perinuclear localization, possibly indicating that their extracellular domain was misfolded. Most KIR2DL2/3 alleles possess an arginine at position 41 (R41), and we predicted through molecular modeling and demonstrated by mutagenesis that R41 most likely interacts with the nearby residues Y77 and D47. Interaction between these residues would maintain C strand contact with the C' and F strands of the D1 domain 
-sheet. Furthermore, R41 and Y77 are conserved in the C and F strand amino acid alignments of Ig-like superfamily members, and may therefore be necessary for the structural integrity of other immune response proteins. Our data indicate that the extracellular T41 polymorphism encoded by the KIR2DL2*004 allele most likely results in misfolding of the D1 domain and complete intracellular retention of the receptor.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
1 Funding from the Office of Naval Research N00014-04-1-0398 and N00014-00-1-0898 to the C. W. Bill Young Marrow Donor Recruitment and Research Program supported this research.
2 The views expressed in this article are those of the authors and do not reflect the official policy of the Department of Navy, the Department of Defense, or the U.S. Government.
3 Address correspondence and reprint requests to Dr. Carolyn Katovich Hurley, Research Building Room E404, Georgetown University Medical Center, 3970 Reservoir Road N.W., Washington, DC 20057. E-mail address: hurleyc{at}georgetown.edu
4 Abbreviations used in this paper: KIR, killer Ig-like receptor; 2D, two domains; 3D, three domains; 2DL, 2D, long cytoplasmic tail; 3DL, 3D, long cytoplasmic tail; 2DS, 2D, short cytoplasmic tail; 3DS, 3D, short cytoplasmic tail; MD, molecular dynamics; MFI, mean fluorescence intensity; PNGase, peptide-N-glycosidase.
This article has been cited by other articles:
|
|
 |
|
  J. Yu, G. Heller, J. Chewning, S. Kim, W. M. Yokoyama, and K. C. Hsu Hierarchy of the Human Natural Killer Cell Response Is Determined by Class and Quantity of Inhibitory Receptors for Self-HLA-B and HLA-C Ligands J. Immunol., November 1, 2007; 179(9): 5977 - 5989. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
