Project description:Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening adverse drug reactions characterized by massive epidermal necrosis, in which the specific danger signals involved remain unclear. Here we show that blister cells from skin lesions of SJS-TEN primarily consist of cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells, and both blister fluids and cells were cytotoxic. Gene expression profiling identified granulysin as the most highly expressed cytotoxic molecule, confirmed by quantitative PCR and immunohistochemistry. Granulysin concentrations in the blister fluids were two to four orders of magnitude higher than perforin, granzyme B or soluble Fas ligand concentrations, and depleting granulysin reduced the cytotoxicity. Granulysin in the blister fluids was a 15-kDa secretory form, and injection of it into mouse skin resulted in features mimicking SJS-TEN. Our findings demonstrate that secretory granulysin is a key molecule responsible for the disseminated keratinocyte death in SJS-TEN and highlight a mechanism for CTL- or NK cell—mediated cytotoxicity that does not require direct cellular contact.
Project description:Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening adverse drug reactions characterized by massive epidermal necrosis, in which the specific danger signals involved remain unclear. Here we show that blister cells from skin lesions of SJS-TEN primarily consist of cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells, and both blister fluids and cells were cytotoxic. Gene expression profiling identified granulysin as the most highly expressed cytotoxic molecule, confirmed by quantitative PCR and immunohistochemistry. Granulysin concentrations in the blister fluids were two to four orders of magnitude higher than perforin, granzyme B or soluble Fas ligand concentrations, and depleting granulysin reduced the cytotoxicity. Granulysin in the blister fluids was a 15-kDa secretory form, and injection of it into mouse skin resulted in features mimicking SJS-TEN. Our findings demonstrate that secretory granulysin is a key molecule responsible for the disseminated keratinocyte death in SJS-TEN and highlight a mechanism for CTL- or NK cell—mediated cytotoxicity that does not require direct cellular contact.
Project description:Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis; (TEN) are life-threatening adverse drug reactions characterized; by massive epidermal necrosis, in which the specific danger; signals involved remain unclear. Here we show that blister; cells from skin lesions of SJS-TEN primarily consist of cytotoxic; T lymphocytes (CTLs) and natural killer (NK) cells, and both; blister fluids and cells were cytotoxic. Gene expression profiling; identified granulysin as the most highly expressed cytotoxic; molecule, confirmed by quantitative PCR and immunohistochemistry. Granulysin concentrations in the blister fluids; were two to four orders of magnitude higher than perforin,; granzyme B or soluble Fas ligand concentrations, and depleting; granulysin reduced the cytotoxicity. Granulysin in the blister; fluids was a 15-kDa secretory form, and injection of it into; mouse skin resulted in features mimicking SJS-TEN. Our; findings demonstrate that secretory granulysin is a key molecule; responsible for the disseminated keratinocyte death in SJS-TEN; and highlight a mechanism for CTL- or NK cellâmediated; cytotoxicity that does not require direct cellular contact. Experiment Overall Design: Blood samples were obtained from 5 different patients with SJS/TEN. The peripheral blood mononuclear cells (PBMCs) were isolated from the whole blood samples by Ficoll-Isopaque (Pharmacia Fine Chemicals) density gradient centrifugation. Total RNA from PBMC was isolated using the RNeasy kit (Qiagen). The 28S and 18S ribosomal RNA peak ratios were determined using microfluidics technology (Agilent). RNA was subjected to reverse transcription using the Superscript II kit (Invitrogen), and the cleaned cRNA was then hybridized to an Affymetrix human genome U133 plus 2.0 array.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:Immune checkpoint inhibitors (ICI) represent new anticancer agents and have been used worldwide. However, ICI can potentially induce life-threatening severe cutaneous adverse reaction (SCAR), such as Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), hindering continuous ICI therapy. We examined 6 cohorts within 25 ICI-induced SJS/TEN patients and conducted single-cell RNA sequencing (scRNA-seq) analysis, which revealed overexpression of macrophage-derived CXCL10 that recruited CXCR3+ cytotoxic T lymphocytes (CTL) in blister cells from ICI-SJS/TEN skin lesions. ScRNA expression profiles and ex vivo blocking studies further identified TNF signaling as the key pathway responsible for macrophage-derived CXCL10 and CTL activation. Based on the trajectory analysis, ICI-activated T cells from whole blood are proposed to serve as the initial cells involved in inflammation, that lead to monocytes differentiating into macrophages and increasing their susceptibility to migrate to the lesion sites. Compared with systemic corticosteroids treatment, ICI-induced SJS/TEN patients treated with biologic TNF blockade showed a significantly rapid recovery and no recurrence of SCAR with continuous ICI therapy. Our findings identified that macrophage-eliciting CTL contribute the pathogenesis of ICI-induced epidermal necrolysis and provide the therapeutic targets for the management and prevention of SCAR induced by ICI therapy.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
2011-02-19 | GSE20463 | GEO
Project description:Blister cells and PBMCs from patients with SJS-TEN