A quantitative real time PCR method to analyze T cell receptor Vβ subgroup expansion by staphylococcal superantigens

Seo, Keun Seok; Park, Joo Youn; Terman, David S.; Bohach, Gregory A.

doi:10.1186/1479-5876-8-2

Cited by 40 publications

(42 citation statements)

References 33 publications

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“…9C). These results were identical to those previously observed with CD4+ T cells (29). Flow cytometry results further confirmed the quantitative real time PCR results showing an increase of Vβ 14 after stimulation with SEC1 (Fig.…”

Section: Resultssupporting

confidence: 92%

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Induction of Immunosuppressive CD8+CD25+FOXP3+ Regulatory T Cells by Suboptimal Stimulation with Staphylococcal Enterotoxin C1

Lee

Park

et al. 2018

The Journal of Immunology

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Superantigens (SAgs) produced by S. aureus induce proliferation of T cells bearing specific TCR Vβ sequences and massive cytokinemia that cause toxic shock syndrome at high concentrations. However, the biological relevance of SAgs produced at very low concentrations during asymptomatic colonization or chronic infections is not understood. In this study, we demonstrate that suboptimal stimulation of human PBMCs with a low concentration (1 ng/ml) of staphylococcal enterotoxin C1 (SEC1), at which half-maximal T cell proliferation was observed, induced CD8+CD25+ T cells expressing markers related to regulatory T cells (Tregs) such as IFN-γ, IL-10, TGF-β, FOXP3+, CD28+, CTLA4+, TNFR2+, CD45RO+, and HLA-DR+. Importantly, these CD8+CD25+ T cells suppressed responder cell proliferation mediated by contact-dependent and soluble factor-dependent manners, involving galectin-1 and granzymes, respectively. By contrast, optimal stimulation of human PBMCs with a high concentration (1 μg/ml) of SEC1, at which maximal T cell proliferation was observed, also induced similar expression of markers related to Tregs including FOXP3 in CD8+CD25+ cells, but these T cells were not functionally immunosuppressive. We further demonstrated that SAg induced TCR Vβ- and MHC II-restricted expansion of immunosuppressive CD8+CD25 T cells is independent of CD4+ T cells. Our results suggest that the concentration of SAg remarkably affects the functional characteristics of activated T cells, and low concentrations of SAg produced during asymptomatic colonization or chronic S. aureus infection induce immunosuppressive CD8+ regulatory T cells, potentially promoting colonization, propagation, and invasion of S. aureus in the host.

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Section: Resultssupporting

confidence: 92%

“…Selective expansion of TCR Vβ was assessed by quantitative real-time PCR using an ABI Prism 7500 real-time PCR system (Applied Biosystems, Foster City, CA) as described previously (29). …”

Section: Methodsmentioning

confidence: 99%

Induction of Immunosuppressive CD8+CD25+FOXP3+ Regulatory T Cells by Suboptimal Stimulation with Staphylococcal Enterotoxin C1

Lee

Park

et al. 2018

The Journal of Immunology

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“…15 However, previous investigations did not detect any Vb11 expansion in response to a number of staphylococcal SAgs including those tested in our study. 52,53 We found that human iNKT cells upregulate their CD69 expression shortly after exposure to SEB, which provides the initial report that human iNKT cells are responsive to bacterial SAgs. These discrepancies may be because of different readouts used (Vb11 expansion among PBMCs in previous studies as opposed to early CD69 expression on iNKT cells in our study).…”

Section: Human Inkt Cells Are Activated By Bacterial Sagsmentioning

confidence: 61%

CD1d‐independent activation of mouse and human iNKT cells by bacterial superantigens

et al. 2011

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Invariant NKT (iNKT) cells are infrequent but important immunomodulatory lymphocytes that exhibit CD1d-restricted reactivity with glycolipid Ags. iNKT cells express a unique T-cell receptor (TCR) composed of an invariant a-chain, paired with a limited range of b-chains. Superantigens (SAgs) are microbial toxins defined by their ability to activate conventional T cells in a TCR b-chain variable domain (Vb)-specific manner. However, whether iNKT cells are directly activated by bacterial SAgs remains an open question. Herein, we explored the responsiveness of mouse and human iNKT cells to a panel of staphylococcal and streptococcal SAgs and examined the contribution of major histocompatibility complex (MHC) class II and CD1d to these responses. Bacterial SAgs that target mouse Vb8, such as staphylococcal enterotoxin B (SEB), were able to activate mouse hybridoma and primary hepatic iNKT cells in the presence of mouse APCs expressing human leukocyte antigen (HLA)-DR4. iNKT cell-mediated cytokine secretion in SEB-challenged HLA-DR4-transgenic mice was CD1d-independent and accompanied by a high interferon-c:interleukin-4 ratio consistent with an in vivo Th1 bias. Furthermore, iNKT cells from SEB-injected HLA-DR4-transgenic mice, and iNKT cells from SEB-treated human PBMCs, showed early activation by intracellular cytokine staining and CD69 expression. Unlike iNKT cell stimulation by a-galactosylceramide, stimulation by SEB did not induce TCR downregulation of either mouse or human iNKT cells. We conclude that Vb8-targeting bacterial SAgs can activate iNKT cells by utilizing a novel pathway that requires MHC class II interactions, but not CD1d. Therefore, iNKT cells fulfill important effector functions in response to bacterial SAgs and may provide attractive targets in the management of SAg-induced illnesses.

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“…28 The analysis of TRBV usage in an individual can help in the evaluation of the immune response in a variety of conditions over the course of the disease. 29 Many studies have determined that the usage frequency of antigen-specific TRBV families in subjects with either virus infection or cancer can be different. 30,31 In the current study, the increased expression of several TRBV families was detected in CD4 1 and CD8 1 T-cell populations, which is consistent with observations that the T-cell immune response to HBV antigens involves multiple TRBV families.…”

Section: In Cd4mentioning

confidence: 99%

Profiling the repertoire of T-cell receptor beta-chain variable genes in peripheral blood lymphocytes from subjects who have recovered from acute hepatitis B virus infection

Yang

Chen

et al. 2014

Cell Mol Immunol

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The profile of T-cell receptor beta-chain variable (TRBV) genes usually skews in subjects with virus infection or cancer. The gene melting spectral pattern (GMSP) can be used to determine the profile of the TRBV gene family. To explore the portrait of the TRBV family in peripheral blood lymphocytes from subjects who have recovered from acute hepatitis B virus infection (AHI), peripheral blood mononuclear cells (PBMCs) were separated and further sorted into CD41 and CD8 1T-cell subsets. The molecular features of the TRBV complementary determining region 3 (CDR3) motifs were determined using GMSP analysis. When a GMSP profile showed a single peak, the monoclonally expanded TRBV gene was cloned and sequenced. Skewed expansions of multiple TRBV genes were observed among the CD4 1 and CD8 1 T-cell subsets and the PBMCs. The frequency of monoclonally expanded TRBV genes in the CD8 1 T-cell subset was significantly higher than that of the CD4 1 T-cell subset and the PBMCs. Compared to other members of the TRBV gene family, TRBV11, BV15 and BV20 were predominantly expressed in the repertoire of peripheral blood lymphocytes in recovered AHI subjects. The relatively conserved amino acid motifs of TRBV5.1 and BV20 CDR3 were also detected in the CD4 1 and CD8 1 T-cell subsets. These results demonstrate the presence of multiple biased TRBV families in recovered AHI subjects. TRBV11, BV15 and BV20, especially from the CD8 1 T-cell subset, may be relevant to the pathogenesis of subjects with AHI. The preferentially selected TRBV5.1 and BV20 with the relatively conserved CDR3 motif may be potential targets for personalized treatments of chronic HBV infection.

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A quantitative real time PCR method to analyze T cell receptor Vβ subgroup expansion by staphylococcal superantigens

Cited by 40 publications

References 33 publications

Induction of Immunosuppressive CD8+CD25+FOXP3+ Regulatory T Cells by Suboptimal Stimulation with Staphylococcal Enterotoxin C1

Induction of Immunosuppressive CD8+CD25+FOXP3+ Regulatory T Cells by Suboptimal Stimulation with Staphylococcal Enterotoxin C1

CD1d‐independent activation of mouse and human iNKT cells by bacterial superantigens

Profiling the repertoire of T-cell receptor beta-chain variable genes in peripheral blood lymphocytes from subjects who have recovered from acute hepatitis B virus infection

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