Staphylococcal Enterotoxin-Like Toxins U2 and V, Two New Staphylococcal Superantigens Arising from Recombination within the Enterotoxin Gene Cluster

ABSTRACT To test the hypothesis that the Staphylococcus aureus enterotoxin gene cluster (egc) can generate new enterotoxin genes by recombination, we analyzed the egc locus in a broad panel of 666 clinical isolates of S. aureus. egc was present in 63% of isolates, confirming its high prevalence. The archetypal organization of the egc locus, consisting of five enterotoxin genes plus two pseudogenes, was found in 409 of 421 egc-positive strains. The egc locus was incomplete in a few strains and occasionally harbored an insertion sequence and transposase genes. These strains may represent evolutionary intermediates of the egc locus. One strain with an atypical egc locus produced two new enterotoxins, designated SElV and SElU2, generated by (i) recombination between selm and sei, producing selv, and (ii) a limited deletion in the φent1-φent2 pseudogenes, producing selu2. Recombinant SElV and SElU2 had superantigen activity, as they specifically activated the T-cell families Vβ 6, Vβ 18, and Vβ 21 (SElV) and Vβ 13.2 and Vβ 14 (SElU2). Immunoscope analysis showed a Gaussian CDR3 size distribution of T-cell receptor Vβ chain junctional transcripts of expanded Vβ subsets in toxin-stimulated cultures, reflecting a high level of polyclonality. These data show that egc is indeed capable of generating new superantigen genes through recombination.

Download Full-text

High Affinity of Interaction between Superantigen and T Cell Receptor Vβ Molecules Induces a High Level and Prolonged Expansion of Superantigen-reactive CD4+T Cells

Journal of Biological Chemistry ◽

10.1074/jbc.m110.140871 ◽

2010 ◽

Vol 285 (40) ◽

pp. 30427-30435 ◽

Cited By ~ 7

Author(s):

Katsuhiko Omoe ◽

Wataru Nunomura ◽

Hidehito Kato ◽

Zhong-Juan Li ◽

Osamu Igarashi ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Receptor ◽

Cd4 T Cells ◽

Cell Receptor ◽

High Affinity ◽

High Level ◽

T Cell Receptor Vβ

Download Full-text

Linkage between bronchial responsiveness to methacholine and gene markers of IL-4 cytokine gene cluster and T-cell receptor alpha/delta gene complex in Korean nuclear families

Clinical & Experimental Allergy ◽

10.1046/j.1365-2222.2001.00952.x ◽

2001 ◽

Vol 31 (1) ◽

pp. 103-109 ◽

Cited By ~ 2

Author(s):

S.-H. Cho ◽

J.-W. Son ◽

Y.-Y. Koh ◽

K.-U. Min ◽

Y.-Y. Kim ◽

...

Keyword(s):

T Cell ◽

Gene Cluster ◽

T Cell Receptor ◽

Cell Receptor ◽

Gene Complex ◽

Cytokine Gene ◽

Gene Markers ◽

Bronchial Responsiveness ◽

Nuclear Families ◽

Cell Receptor Alpha

Download Full-text

Selection for T-cell receptor Vβ–Dβ–Jβ gene rearrangements with specificity for a myelin basic protein peptide in brain lesions of multiple sclerosis

Nature ◽

10.1038/362068a0 ◽

1993 ◽

Vol 362 (6415) ◽

pp. 68-70 ◽

Cited By ~ 288

Author(s):

Jorge R. Oksenberg ◽

Michael A. Panzara ◽

Ann B. Begovich ◽

Dennis Mitchell ◽

Henry A. Erlich ◽

...

Keyword(s):

Multiple Sclerosis ◽

T Cell ◽

Myelin Basic Protein ◽

T Cell Receptor ◽

Basic Protein ◽

Cell Receptor ◽

Brain Lesions ◽

Gene Rearrangements ◽

Selection For ◽

T Cell Receptor Vβ

Download Full-text

Simplified Fluorescent Multiplex PCR Method for Evaluation of the T-Cell Receptor Vβ-Chain Repertoire

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.12.4.477-483.2005 ◽

2005 ◽

Vol 12 (4) ◽

pp. 477-483 ◽

Cited By ~ 2

Author(s):

Sanjit Fernandes ◽

Surendra Chavan ◽

Vivek Chitnis ◽

Nina Kohn ◽

Savita Pahwa

Keyword(s):

T Cell ◽

Multiplex Pcr ◽

T Cell Receptor ◽

Cell Receptor ◽

T Cell Subsets ◽

Clinical Samples ◽

Cdr3 Length ◽

Pcr Products ◽

Pcr Method ◽

T Cell Receptor Vβ

ABSTRACTRationale: evaluation of the T-cell receptor (TCR) Vβ-chain repertoire by PCR-based CDR3 length analysis allows fine resolution of the usage of the TCR Vβ repertoire and is a sensitive tool to monitor changes in the T-cell compartment. A multiplex PCR method employing 24 labeled upstream Vβ primers instead of the conventionally labeled downstream Cβ primer is described. Method: RNA was isolated from purified CD4 and CD8 T-cell subsets from umbilical cord blood and clinical samples using TRI reagent followed by reverse transcription using a Cβ primer and an Omniscript RT kit. The 24 Vβ primers were multiplexed based on compatibility and product sizes into seven reactions. cDNA was amplified using 24 Vβ primers (labeled with tetrachloro-6-cardoxyfluorescein, 6-carboxyfluorescein, and hexachloro-6-carboxyfluorescein), an unlabeled Cβ primer, and Taqgold polymerase. The fluorescent PCR products were resolved on an automated DNA sequencer and analyzed using the Genotyper 2.1 software. Results: Vβ spectratypes of excellent resolution were obtained with RNA amounts of 250 ng using the labeled Vβ primers. The resolution was superior to that obtained with the labeled Cβ primer assay. Also the numbers of PCRs were reduced to 7 from the 12 required in the Cβ labeling method, and the sample processing time was reduced by half. Conclusion: The method described for T-cell receptor Vβ-chain repertoire analysis eliminates tedious dilutions and results in superior resolution with small amounts of RNA. The fast throughput makes this method suitable for automation and offers the feasibility to perform TCR Vβ repertoire analyses in clinical trials.

Download Full-text