The Experts below are selected from a list of 36 Experts worldwide ranked by ideXlab platform

Carl G Becker - One of the best experts on this subject based on the ideXlab platform.

  • chArActerizAtion of the tobAcco glycoProtein surfAce binding property of heArt And skeletAl muscle cells i modulAtion of the heArt cell membrAne tgp interAction by Anti tgp igg
    Archives of Toxicology, 1995
    Co-Authors: Charles A Santosbuch, Harry R Hall, Fausto Farfan, Irene Orlow, Adolfo Firpo, Betsy F Von Kreuter, Carl G Becker
    Abstract:

    MonolAyers of L6 rAt skeletAl myoblAst cells formed surfAce binding isotherms with the purified tobAcco leAf glycoProtein TGP1 And the enriched cigArette tAr glycoProtein TGP2. ScAtchArd AnAlysis showed thAt the binding in the rAnge of the limited concentrAtions tested wAs to A single clAss molecule And the cAlculAted Affinity constAnt (Kd) for TGP1 And TGP2 showed similAr vAlues (9.78 × 10−13 M And 3.09 × 10−13 M, respectively). The bound TGPs were Almost totAlly displAced by excess nonrAdiolAbeled molecules. The cAlculAted BmAx of the L6 myoblAst monolAyer wAs 2.93 fmol for TGP1 And 0.217 fmol for TGP2 per 32.2 mm2. GuineA pig heArt sArcolemmA binding isotherms were Also formed with rAdiolAbeled TGP1 And TGP2. The interAction of tobAcco leAf TGP1 with the heArt cell membrAnes wAs irreversible becAuse only 15–20% of the bound TGP1 wAs displAced by 100-fold, non-lAbeled molecules but the interAction of tAr TGP2 with heArt sArcolemmA wAs reversible And probAbly sAturAble. The heArt sArcolemmA TGP2 Affinity constAnt (Kd) wAs 5.88 × 10−7 M And the BmAx, 2.45 × 10−8 M per 12.5 μg sArcolemmA. PretreAtment of heArt sArcolemmA with increAsing concentrAtions of leAf TGP1 did not displAce tAr TGP2 binding but its Absorption on the membrAne resulted in increAsed TGP2 sArcolemmA AttAchment by A complex And unexplAined mechAnisms. IncreAsing concentrAtions of the serA of 10 of 15 guineA pigs (67%) thAt received mAinstreAm emissions of tobAcco smoke from A University of Kentucky cigArette smoking mAchine for 152 dAys, displAced cigArette tAr TGP2 heArt cell sArcolemmA AttAchment And this inhibition wAs significAntly different from thAt produced by the serA of shAm smoked And of nonexposed AnimAls (MAnn-Whitney test, p=0.0082). StAphylococcus Protein A inhibited the displAcement of TGP2 produced by the serA of cigArette smoke exposed guineA pigs And this observAtion indicAted thAt this Action wAs mediAted by IgG molecules. The specific immunoprecipitAtion of A rAdiolAbeled surfAce epitope of the L6 myoblAst monolAyers pretreAted with TGP1 or TGP2 by immune IgG AgAinst TGP2 And by the IgG of An Antiserum AgAinst stAndArd TGP showed thAt the tobAcco glycoProteins AttAched to A unit polypeptide of the plAsmA membrAne of the muscle cells of ApproximAtely 76 kDA. These dAtA support the notion thAt TGP molecules in cigArette smoke Are Absorbed systemicAlly on smoking And mAy hAve A direct toxic effect when they AttAch to the surfAce TGP binding Proteins of heArt And skeletAl muscle cells.

Barbara J Vilen - One of the best experts on this subject based on the ideXlab platform.

  • StAphylococcus Aureus Protein A disrupts immunity mediAted by long lived plAsmA cells
    Journal of Immunology, 2017
    Co-Authors: Amanda B Keener, Lance T Thurlow, Sun Ah Kang, Nicholas A Spidale, Stephen H Clarke, Kenji M Cunnion, Roland Tisch, Anthony R Richardson, Barbara J Vilen
    Abstract:

    Infection with StAphylococcus Aureus does not induce long-lived protective immunity for reAsons thAt Are not completely understood. HumAn And murine vAccine studies support A role for Abs in protecting AgAinst recurring infections, but S. Aureus modulAtes the B cell response through expression of StAphylococcus Protein A (SpA), A surfAce Protein thAt drives polyclonAl B cell expAnsion And induces cell deAth in the Absence of costimulAtion. In this murine study, we show thAt SpA Altered the fAte of plAsmAblAsts And plAsmA cells (PCs) by enhAncing the short-lived extrAfolliculAr response And reducing the pool of bone mArrow (BM)-resident long-lived PCs. The Absence of long-lived PCs wAs AssociAted with A rApid decline in Ag-specific clAss-switched Ab. In contrAst, when previously inoculAted mice were chAllenged with An isogenic SpA-deficient S. Aureus mutAnt, cells proliferAted in the BM survivAl niches And sustAined long-term Ab titers. The effects of SpA on PC fAte were limited to the secondAry response, becAuse Ab levels And the formAtion of B cell memory occurred normAlly during the primAry response in mice inoculAted with wild-type or SpA-deficient S. Aureus mutAnt. Thus, fAilure to estAblish long-term protective Ab titers AgAinst S. Aureus wAs not A consequence of diminished formAtion of B cell memory; insteAd, SpA reduced the proliferAtive cApAcity of PCs thAt entered the BM, diminishing the number of cells in the long-lived pool.

Charles A Santosbuch - One of the best experts on this subject based on the ideXlab platform.

  • chArActerizAtion of the tobAcco glycoProtein surfAce binding property of heArt And skeletAl muscle cells i modulAtion of the heArt cell membrAne tgp interAction by Anti tgp igg
    Archives of Toxicology, 1995
    Co-Authors: Charles A Santosbuch, Harry R Hall, Fausto Farfan, Irene Orlow, Adolfo Firpo, Betsy F Von Kreuter, Carl G Becker
    Abstract:

    MonolAyers of L6 rAt skeletAl myoblAst cells formed surfAce binding isotherms with the purified tobAcco leAf glycoProtein TGP1 And the enriched cigArette tAr glycoProtein TGP2. ScAtchArd AnAlysis showed thAt the binding in the rAnge of the limited concentrAtions tested wAs to A single clAss molecule And the cAlculAted Affinity constAnt (Kd) for TGP1 And TGP2 showed similAr vAlues (9.78 × 10−13 M And 3.09 × 10−13 M, respectively). The bound TGPs were Almost totAlly displAced by excess nonrAdiolAbeled molecules. The cAlculAted BmAx of the L6 myoblAst monolAyer wAs 2.93 fmol for TGP1 And 0.217 fmol for TGP2 per 32.2 mm2. GuineA pig heArt sArcolemmA binding isotherms were Also formed with rAdiolAbeled TGP1 And TGP2. The interAction of tobAcco leAf TGP1 with the heArt cell membrAnes wAs irreversible becAuse only 15–20% of the bound TGP1 wAs displAced by 100-fold, non-lAbeled molecules but the interAction of tAr TGP2 with heArt sArcolemmA wAs reversible And probAbly sAturAble. The heArt sArcolemmA TGP2 Affinity constAnt (Kd) wAs 5.88 × 10−7 M And the BmAx, 2.45 × 10−8 M per 12.5 μg sArcolemmA. PretreAtment of heArt sArcolemmA with increAsing concentrAtions of leAf TGP1 did not displAce tAr TGP2 binding but its Absorption on the membrAne resulted in increAsed TGP2 sArcolemmA AttAchment by A complex And unexplAined mechAnisms. IncreAsing concentrAtions of the serA of 10 of 15 guineA pigs (67%) thAt received mAinstreAm emissions of tobAcco smoke from A University of Kentucky cigArette smoking mAchine for 152 dAys, displAced cigArette tAr TGP2 heArt cell sArcolemmA AttAchment And this inhibition wAs significAntly different from thAt produced by the serA of shAm smoked And of nonexposed AnimAls (MAnn-Whitney test, p=0.0082). StAphylococcus Protein A inhibited the displAcement of TGP2 produced by the serA of cigArette smoke exposed guineA pigs And this observAtion indicAted thAt this Action wAs mediAted by IgG molecules. The specific immunoprecipitAtion of A rAdiolAbeled surfAce epitope of the L6 myoblAst monolAyers pretreAted with TGP1 or TGP2 by immune IgG AgAinst TGP2 And by the IgG of An Antiserum AgAinst stAndArd TGP showed thAt the tobAcco glycoProteins AttAched to A unit polypeptide of the plAsmA membrAne of the muscle cells of ApproximAtely 76 kDA. These dAtA support the notion thAt TGP molecules in cigArette smoke Are Absorbed systemicAlly on smoking And mAy hAve A direct toxic effect when they AttAch to the surfAce TGP binding Proteins of heArt And skeletAl muscle cells.

Amanda B Keener - One of the best experts on this subject based on the ideXlab platform.

  • StAphylococcus Aureus Protein A disrupts immunity mediAted by long lived plAsmA cells
    Journal of Immunology, 2017
    Co-Authors: Amanda B Keener, Lance T Thurlow, Sun Ah Kang, Nicholas A Spidale, Stephen H Clarke, Kenji M Cunnion, Roland Tisch, Anthony R Richardson, Barbara J Vilen
    Abstract:

    Infection with StAphylococcus Aureus does not induce long-lived protective immunity for reAsons thAt Are not completely understood. HumAn And murine vAccine studies support A role for Abs in protecting AgAinst recurring infections, but S. Aureus modulAtes the B cell response through expression of StAphylococcus Protein A (SpA), A surfAce Protein thAt drives polyclonAl B cell expAnsion And induces cell deAth in the Absence of costimulAtion. In this murine study, we show thAt SpA Altered the fAte of plAsmAblAsts And plAsmA cells (PCs) by enhAncing the short-lived extrAfolliculAr response And reducing the pool of bone mArrow (BM)-resident long-lived PCs. The Absence of long-lived PCs wAs AssociAted with A rApid decline in Ag-specific clAss-switched Ab. In contrAst, when previously inoculAted mice were chAllenged with An isogenic SpA-deficient S. Aureus mutAnt, cells proliferAted in the BM survivAl niches And sustAined long-term Ab titers. The effects of SpA on PC fAte were limited to the secondAry response, becAuse Ab levels And the formAtion of B cell memory occurred normAlly during the primAry response in mice inoculAted with wild-type or SpA-deficient S. Aureus mutAnt. Thus, fAilure to estAblish long-term protective Ab titers AgAinst S. Aureus wAs not A consequence of diminished formAtion of B cell memory; insteAd, SpA reduced the proliferAtive cApAcity of PCs thAt entered the BM, diminishing the number of cells in the long-lived pool.

Fenwei Wang - One of the best experts on this subject based on the ideXlab platform.

  • nAno mAgnetic immunosensor bAsed on StAphylococcus Protein A And the AmplificAtion effect of hrp conjugAted phAge Antibody
    Sensors, 2015
    Co-Authors: Xihui Mu, Zhaoyang Tong, Qibin Huang, Jinping Zhang, Fenwei Wang
    Abstract:

    In this reseArch, super-pArAmAgnetic Fe3O4 nAnopArticles (mAgnetic pArticles) were coAted with StAphylococcus Protein A (SPA) And coupled with polyclonAl Antibody (pcAb) to construct mAgnetic cApturing probes, And HRP-conjugAted phAge Antibody wAs then used As specific detecting probe to design A lAbeled immunosensor for trAce detection of StAphylococcus Aureus enterotoxin B (SEB). The lineAr detection rAnge of the sensor wAs 0.008~125 µg/L, the regression equAtion wAs Y = 0.487X + 1.2 (R = 0.996, N = 15, p < 0.0001), the limit of detection (LOD) wAs 0.008 µg/L, And the limit of quAntificAtion (LOQ) wAs 0.008 µg/L. HRP-conjugAted phAge Antibody, SPA And mAgnetic pArticles cAn enhAnce the sensitivity 4-fold, 3-fold And 2.6-fold higher, respectively. CompAred with conventionAl double-Antibody sAndwich ELISA, the detection sensitivity of the sensor wAs 31-fold higher resulting from the integrAted Amplifying effect. The immunosensor integrAtes the unique AdvAntAges of SPA-oriented Antibody As mAgnetic cApturing probe, HRP-conjugAted phAge Antibody As detecting probe, mAgnetic sepArAtion immunoAssAy technique, And severAl other AdvAnced techniques, so it Achieves high sensitivity, specificity And interference-resistAnce. It is proven to be well suited for AnAlysis of trAce SEB in vArious environmentAl sAmples with high recovery rAte And reproducibility.