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 Nilsson, H. Articles by Antonsson, P. Search for Related Content PubMed PubMed Citation Articles by Nilsson, H. Articles by Antonsson, P.

Staphylococcal Enterotoxin H Displays Unique MHC Class II-Binding Properties

Helen Nilsson^1,*, Per Björk^*, Mikael Dohlsten and Per Antonsson^*

^* Active Biotech Research AB and Department of Cell and Molecular Biology, Section for Tumor Immunology, Lund University, Lund, Sweden

Staphylococcal enterotoxin H (SEH) has been described as a superantigen by sequence homology with the SEA subfamily and briefly characterized for its in vivo activity. In this study, we demonstrate that SEH is a potent T cell mitogen and inducer of T cell cytotoxicity that possesses unique MHC class II-binding properties. The apparent affinity of SEH for MHC class II molecules is the highest affinity ever measured for a staphylococcal enterotoxin (B_max1/2 0.5 nM for MHC class II expressed on Raji cells). An excess of SEA or SEA_F47A, which has reduced binding to the MHC class II -chain, is able to compete for binding of SEH to MHC class II, indicating an overlap in the binding sites at the MHC class II ß-chain. The binding of SEH to MHC class II is like SEA, SED, and SEE dependent on the presence of zinc ions. However, SEH, in contrast to SEA, binds to the alanine-substituted DR1 molecule, ßH81A, believed to have impaired zinc-bridging capacity. Furthermore, alanine substitution of residues D167, D203, and D208 in SEH decreases the affinity for MHC class II as well as its in vitro potency. Together, this indicates an MHC class II binding site on SEH with a different topology as compared with SEA. These unique binding properties will be beneficial for SEH to overcome MHC class II isotype variability and polymorphism as well as to allow an effective presentation on APCs also at low MHC class II surface expression.

This article has been cited by other articles:

				N. Pumphrey, A. Vuidepot, B. Jakobsen, G. Forsberg, B. Walse, and K. Lindkvist-Petersson Cutting Edge: Evidence of Direct TCR {alpha}-Chain Interaction with Superantigen J. Immunol., September 1, 2007; 179(5): 2700 - 2704. [Abstract] [Full Text] [PDF]

				F. Layer, B. Ghebremedhin, W. Konig, and B. Konig Heterogeneity of Methicillin-Susceptible Staphylococcus aureus Strains at a German University Hospital Implicates the Circulating-Strain Pool as a Potential Source of Emerging Methicillin-Resistant S. aureus Clones. J. Clin. Microbiol., June 1, 2006; 44(6): 2179 - 2185. [Abstract] [Full Text] [PDF]

				K. Petersson, H. Pettersson, N. J. Skartved, B. Walse, and G. Forsberg Staphylococcal Enterotoxin H Induces V{alpha}-Specific Expansion of T Cells J. Immunol., April 15, 2003; 170(8): 4148 - 4154. [Abstract] [Full Text] [PDF]