10 research outputs found
Normal Activation of STAT1 Mutants in Stable Transfectants
<div><p>(A) Western blot of total protein extracts (100 μg) from a parental fibrosarcoma cell line (2C4) and STAT1-deficient U3C fibrosarcoma cell clones, untransfected (U3C) or stably cotransfected with a zeocin-resistance vector and a vector containing a mock (pmock), WT, E320Q, Q463H, or L706S <i>STAT1</i> allele, with antibodies specific for phosphorylated-Tyr-701-STAT1, STAT1, and STAT3. The cells were not stimulated (NS) or were stimulated for 30 min with 10<sup>5</sup> IU/ml IFNA or IFNG.</p><p>(B) Immunofluorescence staining, with a STAT1-specific antibody, of STAT1-deficient U3C fibrosarcoma cell clones, stably cotransfected with a zeocin-resistance vector and a vector containing a WT, E320Q, Q463H, or L706S <i>STAT1</i> allele. The cells were not stimulated (NS) or were stimulated with IFNA or IFNG (10<sup>5</sup> IU/ml) for 30 min.</p><p>For (A) and (B), one experiment representative of three independent experiments is shown.</p></div
Impact of Mutant <i>STAT1</i> Alleles on IFNG- and IFNA-Mediated Immunity
<div><p>(A) Cytokine production in the supernatant of whole blood from healthy controls (C) and patients (P1′s mother, P2, and P3) and their respective “travel” control, not stimulated (NS) or stimulated for 72 h with live BCG alone or BCG plus IL12 or IFNG. The levels of IFNG and IL12 in the supernatant were determined by enzyme-linked immunosorbent assay. One experiment representative of two independent experiments is shown.</p><p>(B) Skin-derived SV40-transformed fibroblasts from a healthy control (C), the three patients under study (P1, P2, P3), a parental fibrosarcoma cell line (2C4), STAT1-deficient U3C fibrosarcoma cell line (U3C), and U3C clones stably transfected with a mock (pmock), WT, E320Q, Q463H, or L706S <i>STAT1</i> alleles, were infected with HSV-1 or VSV, with or without priorstimulation with IFNA (10<sup>5</sup> IU/ml) for 24 h. Viral titers were determined after 48 h of infection. Five independent experiments are shown for the patient's cells and three independent experiments are shown for sarcoma fibroblasts. Each assay is symbolized by a different character.</p></div
Impaired DNA-Binding Activity of STAT1 Mutants in Stable Transfectants
<div><p>(A–D) EMSA of nuclear extracts (5 μg [A and B]; 30 μg [C and D]) from a parental fibrosarcoma cell line (2C4) and STAT1-deficient U3C fibrosarcoma cell clones, untransfected (U3C) or stably cotransfected with a zeocin-resistance vector and a vector containing a mock (pmock), WT, E320Q, Q463H, or L706S <i>STAT1</i> allele. The cells were not stimulated (NS) or were stimulated for 30 min with the indicated doses of IFNG (A and B) or IFNA (C and D). We used the radiolabeled GAS probe FCGR1 (A and B) or an ISRE probe (C and D). For (A–D), one experiment representative of three to five independent experiments is shown.</p><p>(E) Quantification of three independent experiments by PhosphoImager SI (Molecular Dynamics), using the ISRE probe, in response to 10<sup>4</sup> and 10<sup>5</sup> IU/ml IFNA is also presented. The mean, minimum, and maximum values are expressed with respect to the WT stable transfectant clone response (100%).</p></div
Normal Activation but Impaired DNA-Binding Activity of STAT1 in Heterozygous Cells from Patients
<div><p>(A) Western blot of total protein extracts (100 μg) from EBV-transformed B cells derived from a healthy control (C), three patients under study (P1, P2, P3), and a patient with recessive complete STAT1 deficiency (P4) homozygous for the 1758_1759delAG mutation, probed with specific antibodies against phosphorylated-Tyr-701-STAT1, STAT1, and STAT3. EBV-transformed B cells were not stimulated (NS) or were stimulated with IFNA or IFNG (10<sup>5</sup> IU/ml) for 30 min.</p><p>(B) Immunofluorescence staining with a STAT1-specific antibody of skin-derived SV40-transformed fibroblasts from a healthy control (C) and three patients under study (P1, P2, P3). Fibroblasts were not stimulated (NS) or were stimulated with IFNA or IFNG (10<sup>5</sup> IU/ml) for 30 min.</p><p>(C and E) EMSA of nuclear extracts (5 μg) from EBV-transformed B cells derived from a healthy control (C), three patients under study (P1, P2, P3), and the patient with complete STAT1 deficiency (P4). EBV-transformed B cells were not stimulated (NS) or were stimulated for 30 min with 10<sup>3</sup> and 10<sup>5</sup> IU/ml of IFNG (C) and IFNA (E), respectively. Radiolabeled GAS (C) or ISRE (E) probes were used.</p><p>(D) Quantification of four to six independent experiments by PhosphoImager SI (Molecular Dynamics, Piscataway, New Jersey, United States) using the GAS probe in response to 10<sup>5</sup> IU/ml of IFNG is also presented. The mean, minimum, and maximum values are expressed with respect to the positive control response (100%).</p><p>For (A–C) and (E), one experiment representative of three to five independent experiments is shown.</p></div
Impact of <i>STAT1</i> Mutations on Transcription
<div><p>(A) Levels of mRNA corresponding to <i>STAT1,</i> IFNG- and/or IFNA-inducible genes <i>(IRF1</i> and <i>ISG15)</i> and <i>GADP</i> in EBV-transformed B cells from a control (C), the three affected individuals (P1, P2, and P3) and a STAT1-deficient individual (P4), or in the 2C4 parental fibrosarcoma cell line, STAT1-deficient U3C cell line, and U3C cells stably transfected with a mock (pmock), WT, E320Q, Q463H, or L706S <i>STAT1</i> allele, either not stimulated (NS), or stimulated for 2 h with 10<sup>3</sup> of IFNG or 10<sup>4</sup> of IFNA for EBV-transformed B cells and 10<sup>5</sup> IU/ml of IFNG or IFNA for fibroblasts, as detected by Northern blotting.</p><p>(B) Relative real-time PCR of <i>IRF1, ISG15,</i> and <i>MX1,</i> and cDNAs from EBV-transformed B cells derived from a healthy control (C), three patients under study (P1, P2, P3), and a patient with recessive complete STAT1 deficiency (P5) homozygous for the 1928insA <i>STAT1</i> mutation or from parental fibrosarcoma cell line (2C4) and STAT1-deficient U3C fibrosarcoma cell clones, untransfected (U3C) or stably cotransfected with a zeocin-resistance vector and a vector containing a mock, WT, E320Q, Q463H, or L706S <i>STAT1</i> allele stimulated or not stimulated with 10<sup>5</sup> IU/ml of IFNG or IFNA for 1 h and 2 h for EBV-transformed B cells and fibroblasts, respectively, for <i>IRF1,</i> and for 6 h for both cellular types for <i>ISG15</i> and <i>MX1</i>. Means values of duplicates of one experiment are shown with their respective standard variations.</p></div
Molecular Representation of STAT1 Mutants
<div><p>(A) Ribbon representation of the WT STAT1 homodimer complexed with DNA. Secondary structure elements representing the β strands are shown in cyan, and the helices are shown in blue-magenta. Atoms of residues in mutated positions L706, E320, and Q463 (indicated by arrows) are shown in space-filling models. Atoms are shown in red (for oxygen), blue (for nitrogen), and gray (for carbon).</p><p>(B) Magnified focus on the region containing the three mutated residues.</p></div
Mechanism of Dominance of the <i>STAT1</i> Alleles for GAS-Binding Activity and of Recessivity of the <i>STAT1</i> Alleles for ISRE-Binding Activity
<div><p>(A) Western blot of total protein extracts (100 μg) from unstimulated EBV-transformed B-cell lines from a healthy control (+/+), P4′s father (+/−) (heterozygous for the loss-of-expression, loss-of-function <i>STAT1</i> 1758_1759delAG allele), and P5 (−/−) (homozygous for the loss-of-expression, loss-of-function <i>STAT1</i> 1928insA allele), using antibodies specific for STAT1 and STAT3.</p><p>(B) EMSA of nuclear extracts (5 μg) from EBV-transformed B cells derived from a healthy control (+/+), P5 (−/−) (homozygous for the loss-of-expression, loss-of-function <i>STAT1</i> 1928insA allele), and P4′s father (+/−) (heterozygous for the loss-of-expression, loss-of-function <i>STAT1</i> 1758_1759delAG allele). EBV-transformed B cells were not stimulated (NS) or were stimulated for 30 min with 10<sup>5</sup> IU/ml IFNG. A radiolabeled GAS (FCGR1) probe was used.</p><p>(C) (a) Whole-cell extracts of 10<sup>7</sup> STAT1-deficient U3C fibrosarcoma cell clones stably cotransfected with a zeocin-resistance vector and a vector containing a mock (pmock), WT, or L706S <i>STAT1</i> allele were subjected to immunoprecipitation with the following biotinylated peptides: TSFGYDKPHVLV (1), corresponding to the intracellular part of IFNGR1 around the unphosphorylated Tyr-440 residue (Y); TSFG(pTyr)DKPHVLV (2), corresponding to the intracellular part of IFNGR1 around the phosphorylated Tyr-440 residue (pTyr); and SLIG(pTyr)RPTEDSK (3), corresponding to an irrelevant peptide similar to peptide 2. (b) 20 μL of each extract was taken before immunoprecipitation, and Western blotting was performed with STAT1- and STAT3-specific antibodies.</p><p>(D) EMSA of nuclear extracts (5 μg) from EBV-transformed B cells derived from a healthy control (C), P4′s father (+/−) (heterozygous for the loss-of-expression, loss-of-function <i>STAT1</i> 1758_1759delAG allele) and P5 (−/−) (homozygous for the loss-of-expression, loss-of-function <i>STAT1</i> 1928insA allele). EBV-transformed B cells were not stimulated (NS) or were stimulated for 30 min with 10<sup>5</sup> IU/ml of IFNA. A radiolabeled ISRE probe was used.</p><p>(E) Immunoprecipitation with a STAT1-specific antibody, followed by Western blotting with Tyr701-phospho-STAT1–specific, Tyr690-phospho-STAT2–specific, STAT1-specific, and STAT2-specific antibodies, of total protein extracts (1 mg) from a parental fibrosarcoma cell line (2C4), a STAT2-deficient U6A fibrosarcoma cell line, and STAT1-deficient U3C fibrosarcoma cell clones, untransfected (U3C) or stably cotransfected with a zeocin-resistance vector and a vector containing a mock, WT, E320Q, Q463H, or L706S <i>STAT1</i> allele. The cells were not stimulated (NS) or were stimulated for 30 min with 10<sup>5</sup> IU/ml IFNA.</p><p>For (B–E), one experiment representative of two independent experiments is shown.</p></div
Novel <i>STAT1</i> Mutations in Two Kindreds
<div><p>(A) <i>STAT1</i> genotype and clinical phenotype of three kindreds. In kindred A, members I.1 and II.1 had tuberculosis, and III.2 and IV.1 (P1) had severe BCG disease. In kindred B, members I.1 and III. 2 (P2) were infected with M. tuberculosis and <i>M. avium,</i> respectively. Kindred C has been described elsewhere; II.2 (P3) developed disseminated BCG disease. Individuals with clinical disease caused by weakly virulent (BCG or M. avium) and more virulent <i>(M. tuberculosis)</i> mycobacteria are indicated in black and gray, respectively, and healthy individuals are shown in white. The index cases are indicated with an arrow. Genetically affected individuals (heterozygous for any of the three <i>STAT1</i> mutations) with no clinical phenotype at the time of this study are indicated by a vertical line. Known <i>STAT1</i> genotypes (WT, E320Q, Q463H, L706S) are indicated under each individual, with a question mark indicating unknown genotype.</p><p>(B) The human <i>STAT1</i> coding region is shown, with its known pathogenic mutations. The coiled-coil domain (CC), DNA-binding domain (DNA-B), linker domain (L), SH2 domain (SH2), tail segment domain (TS), and <i>trans</i>-activator domain (TA) are indicated, together with their amino-acid boundaries. Tyrosine 701 (Y) is also indicated. Mutations in red are recessive mutations associated with complete STAT1 deficiency (due to a lack of STAT1 production), impaired IFNG-induced GAF activation and IFNA-induced ISGF3 activation, and a syndrome of predisposition to mycobacterial and severe viral disease in homozygous individuals. Mutations in green are associated, in heterozygous individuals, with partial STAT1 deficiency (normal STAT1 expression), impaired IFNG-induced GAS-binding activity but normal IFNA-induced ISRE-binding activity, and MSMD (predisposition to mycobacterial but not viral disease). Mutations reported for the first time in this study are indicated in italics.</p></div
Table indicating the clinical presentations of TB recorded in the fifty patients.
<p>The two patients presenting with IL-12Rβ1 deficiency are in bold. N means number and age is indicated in years.</p
Mendelian mutations in <i>IL12RB1</i> leading to severe tuberculosis in two kindreds.
<p><b>A</b>. Pedigree of the two families (A and B) with IL-12Rβ1 deficiency. Each generation is designated by a roman numeral (I–II), and each individual by an Arabic numeral. The double lines connecting the parents indicate consanguinity. The probands are indicated by an arrow, with black indicating <i>Mycobacterium tuberculosis</i> disease status. Individuals whose genetic status could not be evaluated are indicated by the symbol “E?”. <b>B</b>. Electrophoregram showing the genomic sequences of exons 9 and 5 in patients 1 and 2, respectively, compared with a control sequence. <b>C</b>. Schematic diagram of the coding region of the IL-12Rβ1 chain containing 17 coding exons and encoding a 662-amino acid protein with a leader sequence (exon1, L), extracellular domain (exons 2 to 13, EC), transmembrane domain (exon 14, TM) and an intracellular cytoplasmic domain (exons 15 to 17, IC). Published and unpublished mutations are indicated as follows: missense mutations are shown in purple, nonsense mutations are shown in red and complex mutations are shown in brown. Splicing mutations are shown in blue, large deletions are shown in green, insertions are shown in orange, and duplication is shown in magenta. * The 700+362_1619-944del mutation is the only mutation resulting in at the expression of a protein at the cell surface. Mutations of P1 (K305X) and P2 (R173W) are underlined. <b>D</b>. Chest X ray of patient 1 showing the localization of the disease.</p