Superantigens stimulate a large proportion of T cells through a specific interaction with the beta-chain of the T-cell receptor (TCR). Thus, an individual superantigen such as Mls-1 or staphylococcal enteroxin A, when presented by MHC class II, stimulates T cells bearing specific Vbeta-regions. This project aims to analyze the affinity and structure of the interaction between the TCR beta-chain and the complex of MHC class II with bacterial or retroviral superantigens. A secreted form of the TCR beta-chain and mutant staphylococcal enteroxin superantigens have been used to demonstrate the Vbeta binding site of the superantigen. Recombinant retroviral superantigens will be prepared for studies on the interaction with MHC and TCR. The affinity and rate constants for the reaction of various V-betas with superantigens will be determined using surface plasmon resonance. This will allow a minimal estimate of the affinity required for a beta chain to undergo thymic deletion or peripheral activation. This information will be extremely important in understanding the basis of tolerance induction by negative selection of the thymus. Bacteriophage-display systems will be used to produce new superantigens with different properties. They will be selected for binding to class II or TCR on cells or in solid phase. A major aim is to produce a mutant SEA with high affinity binding for TCR so that it should cause anergy in T cells. It will also be useful for co-crystallization of the TCR with the superantigen.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM046134-06
Application #
2734698
Study Section
Special Emphasis Panel (ZRG2-ALY (01))
Project Start
1992-02-01
Project End
2000-06-30
Budget Start
1998-07-01
Budget End
1999-06-30
Support Year
6
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Scripps Research Institute
Department
Type
DUNS #
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Alam, S Munir; Gascoigne, Nicholas R J (2003) Binding kinetics of superantigen with TCR and MHC class II. Methods Mol Biol 214:65-85
Redpath, S; Ghazal, P; Gascoigne, N R (2001) Hijacking and exploitation of IL-10 by intracellular pathogens. Trends Microbiol 9:86-92
McGuire, M V; Suthipinijtham, P; Gascoigne, N R (2001) The mouse Supt16h/Fact140 gene, encoding part of the FACT chromatin transcription complex, maps close to Tcra and is highly expressed in thymus. Mamm Genome 12:664-7
Gascoigne, N R; Alam, S M; Lin, C M et al. (2000) T cell receptor binding kinetics and special role of Valpha in T cell development and activation. Immunol Res 21:225-31
Redpath, S; Alam, S M; Lin, C M et al. (1999) Cutting edge: trimolecular interaction of TCR with MHC class II and bacterial superantigen shows a similar affinity to MHC:peptide ligands. J Immunol 163:6-10
Redpath, S; Angulo, A; Gascoigne, N R et al. (1999) Murine cytomegalovirus infection down-regulates MHC class II expression on macrophages by induction of IL-10. J Immunol 162:6701-7
Ghoshroy, S; Freedman, K; Lartey, R et al. (1998) Inhibition of plant viral systemic infection by non-toxic concentrations of cadmium. Plant J 13:591-602
Sheng, J; Lartey, R; Ghoshroy, S et al. (1998) An Arabidopsis thaliana mutant with virus-inducible phenotype. Virology 249:119-28
Lartey, R T; Ghoshroy, S; Citovsky, V (1998) Identification of an Arabidopsis thaliana mutation (vsm1) that restricts systemic movement of tobamoviruses. Mol Plant Microbe Interact 11:706-9
Wung, J L; Gascoigne, N R (1997) Selection of phage-displayed superantigen by binding to cell-surface MHC class II. J Immunol Methods 204:33-41

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