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Ian H Mather - One of the best experts on this subject based on the ideXlab platform.
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btn1a1 the mammary gland Butyrophilin and btn2a2 are both inhibitors of t cell activation
2010Co-Authors: Isobel Smith, David A Rhodes, Ian H Mather, Brittany R Knezevic, Johannes U Ammann, Donald B Palmer, John TrowsdaleAbstract:Butyrophilin (BTN) genes encode a set of related proteins. Studies in mice have shown that one of these, BTN1A1, is required for milk lipid secretion in lactation, whereas Butyrophilin-like 2 is a coinhibitor of T cell activation. To understand these disparate roles of BTNs, we first compared the expression and functions of mouse Btn1a1 and Btn2a2. Btn1a1 transcripts were not restricted to lactating mammary tissue but were also found in virgin mammary tissue and, interestingly, spleen and thymus. In confirmation of this, BTN1A1 protein was detected in thymic epithelial cells. By contrast, Btn2a2 transcripts and protein were broadly expressed. Cell surface BTN2A2 protein, such as the B7 family molecule programmed death ligand 1, was upregulated upon activation of T cells. We next examined the potential of both BTN1A1 and BTN2A2 to interact with T cells. Recombinant Fc fusion proteins of murine BTN2A2 and, surprisingly BTN1A1, bound to activated T cells, suggesting the presence of one or more receptors on these cells. Immobilized BTN-Fc fusion proteins, but not MOG-Fc protein, inhibited the proliferation of CD4 and CD8 T cells activated by anti-CD3. BTN1A1 and BTN2A2 also inhibited T cell metabolism, IL-2, and IFN-gamma secretion. Inhibition of proliferation was not abrogated by exogenous IL-2 but could be overcome following costimulation with high levels of anti-CD28 Ab. These data are consistent with a coinhibitory role for mouse BTNs, including BTN1A1, the BTN expressed in the lactating mammary gland and on milk lipid droplets.
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a review and proposed nomenclature for major proteins of the milk fat globule membrane
2000Co-Authors: Ian H MatherAbstract:Abstract The characteristics and possible functions of the most abundant proteins associated with the bovine milk-fat globule membrane are reviewed. Under the auspices of the Milk Protein Nomenclature Committee of the ADSA, a revised nomenclature for the major membrane proteins is proposed and discussed in relation to earlier schemes. We recommend that proteins be assigned specific names as they are identified by molecular cloning and sequencing techniques. The practice of identifying proteins according to their M r , electrophoretic mobility, or staining characteristics should be discontinued, except for uncharacterized proteins. The properties and amino acid sequences of the following proteins are discussed in detail: MUC1, xanthine dehydrogenase/oxidase, CD36, Butyrophilin, adipophilin, periodic acid Schiff 6/7 (PAS 6/7), and fatty acid binding protein. In addition, a compilation of less abundant proteins associated with the bovine milk-fat globule membrane is presented.
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Butyrophilin is expressed in mammary epithelial cells from a single sized messenger rna as a type i membrane glycoprotein
1998Co-Authors: Lisa R Banghart, Lucinda J W Jack, Clayton W Chamberlain, Jorge Velarde, Igor V Korobko, Sherry L Ogg, Vikram N Vakharia, Ian H MatherAbstract:We investigated the expression of Butyrophilin in eukaryotic cells with a view to determining the number of mRNA species, the incorporation of the peptide chain into microsomes, and the topology of the processed protein in biological membranes. Butyrophilin is synthesized from a single sized mRNA in both bovine and murine lactating mammary tissue and associates with microsomal membranes with a type I topology (Nexo·Ccyto) via a single hydrophobic anchor in the middle of the sequence. Several isoelectric variants of the protein were detected in cellular membranes from lactating bovine mammary tissue and in the milk-fat-globule membrane. We found no evidence for soluble forms of Butyrophilin in postmicrosomal supernatants. The 66-kDa protein appears to be subjected to limited proteolysis, giving rise to a 62-kDa fragment lacking the C terminus and to other more minor fragments of lower Mr in the milk-fat-globule membrane. Antipeptide antibodies to epitopes within the N- and C-terminal domains were used to show that Butyrophilin retains a type I topology in plasma membranes when expressed in insect cells from a baculovirus vector, and in secreted milk-fat globules. These data do not agree with previous suggestions that Butyrophilin may exist in cytoplasmic soluble forms, or be reorganized in the plane of the lipid bilayer during secretion in lipid droplets from mammary cells. The results are discussed with reference to the role Butyrophilin may play as the principal scaffold for the assembly of a complex with xanthine oxidase and other proteins that functions in the budding and release of milk-fat globules from the apical surface during lactation.
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structure and sequence of the bovine Butyrophilin gene
1997Co-Authors: Helen W Davey, Ian H Mather, Igor V Korobko, Sherry L Ogg, Yasmin Husaini, Russell G Snell, Richard J WilkinsAbstract:The complete sequence of the bovine Butyrophilin gene (BTN ) is described and compared with the mouse gene (Btn). Both genes contain seven exons separated by six introns, and the organisation of exons is closely associated with structural domains of the protein. Individual exons of BTN and Btn are 68‐87% similar in sequence. There are no canonical TATA or CCAAT boxes associated with the transcription initiation sites in the genes of either species. However, a number of potential binding sites for transcription factors were identified in the 5ae-flanking DNA, some of which may function in regulating expression of the gene in mammary tissue. Conservation of a 110-bp region in the promoters of BTN and Btn may have some functional significance. Cloning and sequencing of BTN provides an additional mammary-specific gene promoter that may be used for driving the expression of transgenes in the lactating mammary gland, and for determining the basis for tissue-specific gene expression. In addition, the sequence of BTN may be used to map intragenic polymorphisms and identify quantitative trait loci in commercial livestock. © 1997 Elsevier Science B.V.
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cloning localization and structure of new members of the Butyrophilin gene family in the juxta telomeric region of the major histocompatibility complex
1997Co-Authors: Rachid Taziahnini, Ian H Mather, Joelle Henry, Claudine Offer, Catherine Bouissoubouchouata, Pierre PontarottiAbstract:New members of the Butyrophilin (BT) gene family have been identified by cDNA and genomic cloning. Six genes are described: BT2.1, 2.2, 2.3, and BT3.1, 3.2, and 3.3. BT2, BT3, and BT form three distinct subfamilies sharing about 95% amino acid identity at the intra subfamily level and 50% identity at the interfamily level. All the BT2 and BT3 subfamily members map close to BT in the juxta-telomeric region of the major histocompatibility complex. The BT2 members have the canonical structural organization of BT, i.e., two immunoglobulin domains followed by a transmembrane anchor and a B30.2 intracytoplasmic domain. In the BT3 subfamily, only BT3.3 has the structural organization of BT. The two other genes, BT3.1 and BT3.2, code for putative protein without the B30.2 domain. In the case of BT3.2, this is due to an Alu insertion in the B30.2 coding exon, leading to a new polyadenylation site.
Daniel Olive - One of the best experts on this subject based on the ideXlab platform.
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Prognostic significance of circulating PD-1, PD-L1, pan-BTN3As, BTN3A1 and BTLA in patients with pancreatic adenocarcinoma
2019Co-Authors: Benjamin Bian, Daniel Olive, Daniele Fanale, Nelson Dusetti, Julie Roque, Sonia Pastor, Anne-sophie Chretien, Lorena Incorvaia, Antonio Russo, Juan IovannaAbstract:PDAC is one of the most heterogeneous cancers with low chemotherapeutic sensitivity due to a dense stroma, a weak vasculature and significant biological aggressivity. In cancer, suppressive immune checkpoints are often hyper-activated to ensure an effective evasion of tumor cells from immune surveillance. These immune checkpoints include in part, the B7/Butyrophilin-like receptors such as Butyrophilin sub-family 3A/CD277 receptors (BTN3A), the B and T lymphocyte attenuator (BTLA) belonging to the B7-like receptors and the programmed death protein (PD-1) with its ligand PD-L1. We evaluated the plasma level of these markers in 32 PDAC patients (learning cohort) by ad hoc developed ELISA's and showed that there are highly correlated. We used ROC curves and univariate analysis to characterize their prognostic relevance in these patients and showed that their plasma level can serve as survival predictor. Plasma level thresholds that correlate with less than six months survival were established for sPD-1 (>8.6 ng/ml), sPD-L1 (>0.36 ng/ml), sBTLA (>1.91 ng/ml), sBTN3A1 (>6.98 ng/ml) and pan-sBTN3A (>6.92 ng/ml). These thresholds were applied in independent validation cohort composed by 27 new samples and could efficiently discriminate short versus long PDAC survivors. Our study reveals that monitoring the concentration of soluble forms of inhibitory immune checkpoints in plasma can help predict survival in PDAC patients and therefore improve their treatments.
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New Insights Into the Regulation of γδ T Cells by BTN3A and Other BTN/BTNL in Tumor Immunity
2018Co-Authors: Juan-luis Blazquez, Audrey Benyamine, Christine Pasero, Daniel OliveAbstract:Recent findings in the immunology field have pointed out the emergent role of Butyrophilins/Butyrophilin-like molecules (BTN/BTNL in human, Btn/Btnl in mouse) in the modulation of γδ T cells. As long as the field develops exponentially, new relationships between certain γδ T cell subsets, on one hand, and their BTN/BTNL counterparts mainly present on epithelial and tumor cells, on the other, are described in the scientific literature. Btnl1/Btnl6 in mice and BTNL3/BTNL8 in humans regulate the homing and maturation of Vγ7+ and Vγ4+ T cells to the gut epithelium. Similarly, Skint-1 has shown to shape the dendritic epidermal T cells repertoire and their activation levels in mice. We and others have identified BTN3A proteins are the key mediators of phosphoantigen sensing by human Vγ9Vδ2 T cells. Here, we first synthesize the modulation of specific γδ T cell subsets by related BTN/BTNL molecules, in human and mice. Then, we focus on the role of BTN3A in the activation of Vγ9Vδ2 T cells, and we highlight the recent advances in the understanding of the expression, regulation, and function of BTN3A in tumor immunity. Hence, recent studies demonstrated that several signals induced by cancer cells or their microenvironment can regulate the expression of BTN3A. Moreover, antibodies targeting BTN3A have shown in vitro and in vivo efficacy in human tumors such as acute myeloid leukemia or pancreatic cancer. We thus finally discuss how these findings could help develop novel γδ T cell-based immunotherapeutical approaches
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the juxtamembrane domain of Butyrophilin btn3a1 controls phosphoantigen mediated activation of human vγ9vδ2 t cells
2017Co-Authors: Cassiemarie Peigne, Daniel Olive, Alexandra Leger, Marieclaude Gesnel, Fabienne Konczak, Marc Bonneville, R Breathnach, Emmanuel ScotetAbstract:Vγ9Vδ2 T lymphocytes are the major human peripheral γδ T cell subset, with broad reactivity against stressed human cells, including tumor cells. Vγ9Vδ2 T cells are specifically activated by small phosphorylated metabolites called phosphoantigens (PAg). Stress-induced changes in target cell PAg levels are specifically detected by Butyrophilin (BTN)3A1, using its intracellular B30.2 domain. This leads to the activation of Vγ9Vδ2 T cells. In this study, we show that changes in the juxtamembrane domain of BTN3A1, but not its transmembrane domain, induce a markedly enhanced or reduced γδ T cell reactivity. There is thus a specific requirement for BTN3A1's juxtamembrane domain for correct γδ T cell-related function. This work identified, as being of particular importance, a juxtamembrane domain region of BTN3A molecules identified as a possible dimerization interface and that is located close to the start of the B30.2 domain.
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Phosphoantigens and Butyrophilin 3A1 induce similar intracellular activation signaling in human TCRVγ9+ γδ T lymphocytes
2014Co-Authors: Emilie Decaup, Daniel Olive, Caroline Duault, Christine Bezombes, Mary Poupot, Ariel Savina, Jean-jacques FourniéAbstract:Human γδ cells expressing TCRVγ9 are T lymphocytes with great potential for cancer immunotherapy and unconventional pattern of antigen specificity. These HLA-unrestricted lymphocytes are specifically reactive to non-peptide metabolites (phosphoantigens) and to the Butyrophilin 3A (BTN3A/CD277) protein. Whether recognition of such highly different structures trigger the same activation signaling pathway remains unclear, however. Here we combined fluorescent cell barcoding and phosphoflow analysis of TCRVγ9(+) T lymphocytes to compare simultaneously the level of several signaling phosphoproteins after activation by phosphoantigen (BrHPP) or by anti-BTN3A (monoclonal antibody 20.1). This approach shows that the same pathways involving ZAP70, PLCγ2, Akt, NFκB p65, MAPK p38 and Erk1, were induced by either of these stimuli. These data strongly suggest the TCRVγ9(+) T lymphocytes detect phosphoantigens and Butyrophilin A3 by the same recognition process.
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vγ9vδ2 tcr activation by phosphorylated antigens requires Butyrophilin 3 a1 btn3a1 and additional genes on human chromosome 6
2014Co-Authors: Felipe Riano, Daniel Olive, Mohindar Murugesh Karunakaran, Lisa Starick, Claus Jurgen Scholz, Volker Kunzmann, Sabine Amslinger, Thomas HerrmannAbstract:Pyrophosphorylated metabolites of isoprenoid-biosynthesis (phosphoantigens, PAgs) activate Vγ9Vδ2 T cells during infections and trigger antitumor activity. This activation depends on expression of Butyrophilin 3 A1 (BTN3A1) by antigen-presenting cells. This report defines the minimal genetic requirements for activation of Vγ9Vδ2 T cells by PAgs and mAb 20.1. We compared PAg-presentation by BTN3A1-transduced CHO hamster cells with that of CHO cells containing the complete human chromosome 6 (Chr6). BTN3A1 expression alone was sufficient for activation of Vγ9Vδ2 T-cell receptor transductants by mAb 20.1., while activation by PAgs also required the presence of Chr6. We take this finding as evidence that gene(s) on Chr6 in addition to BTN3A1 are mandatory for PAg-mediated activation of Vγ9Vδ2 T cells. This observation is important for the design of animal models for PAg-mediated immune responses and provokes speculations about the analogy between genes controlling PAg presentation and MHC-localized genes controlling peptide-antigen presentation.
David F. Wiemer - One of the best experts on this subject based on the ideXlab platform.
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synthesis and bioactivity of the alanyl phosphonamidate stereoisomers derived from a Butyrophilin ligand
2019Co-Authors: Nicholas A Lentini, Chia-hung Christine Hsiao, Andrew J Wiemer, George B Crull, David F. WiemerAbstract:Aryloxy phosphonamidate derivatives of a Butyrophilin 3A1 ligand are stimulants of Vγ9 Vδ2 T cells. However, when bonded to an aryl ester and an amine, the phosphorus is stereogenic, and past compo...
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phosphonamidate prodrugs of a Butyrophilin ligand display plasma stability and potent vγ9 vδ2 t cell stimulation
2018Co-Authors: Nicholas A Lentini, Benjamin J. Foust, Chia-hung Christine Hsiao, Andrew J Wiemer, David F. WiemerAbstract:Small organophosphorus compounds stimulate Vγ9 Vδ2 T cells if they serve as ligands of Butyrophilin 3A1. Because the most potent natural ligand is ( E)-4-hydroxy-3-methyl-but-2-enyl diphosphate (HMBPP), which is the last intermediate in bacterial biosynthesis of isoprenoids that is not found in mammalian metabolism, activation of these T cells represents an important component of the immune response to bacterial infections. To identify Butyrophilin ligands that may have greater plasma stability, and clinical potential, we have prepared a set of aryl phosphonamidate derivatives (9a-i) of the natural ligand. Testing of these new compounds in assays of T cell response has revealed that this strategy can provide compounds with high potency for expansion of Vγ9 Vδ2 T cells (9f, EC50 = 340 pM) and interferon γ production in response to loaded K562 cells (9e, EC50 = 62 nM). Importantly, all compounds of this class display extended plasma stability ( t1/2 > 24 h). These findings increase our understanding of metabolism of Butyrophilin ligands and the structure-activity relationships of phosphonamidate prodrugs.
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Phosphonamidate Prodrugs of a Butyrophilin Ligand Display Plasma Stability and Potent Vγ9 Vδ2 T Cell Stimulation
2018Co-Authors: Nicholas A. Lentini, Benjamin J. Foust, Chia-hung Christine Hsiao, Andrew J Wiemer, David F. WiemerAbstract:Small organophosphorus compounds stimulate Vγ9 Vδ2 T cells if they serve as ligands of Butyrophilin 3A1. Because the most potent natural ligand is (E)-4-hydroxy-3-methyl-but-2-enyl diphosphate (HMBPP), which is the last intermediate in bacterial biosynthesis of isoprenoids that is not found in mammalian metabolism, activation of these T cells represents an important component of the immune response to bacterial infections. To identify Butyrophilin ligands that may have greater plasma stability, and clinical potential, we have prepared a set of aryl phosphonamidate derivatives (9a–i) of the natural ligand. Testing of these new compounds in assays of T cell response has revealed that this strategy can provide compounds with high potency for expansion of Vγ9 Vδ2 T cells (9f, EC50 = 340 pM) and interferon γ production in response to loaded K562 cells (9e, EC50 = 62 nM). Importantly, all compounds of this class display extended plasma stability (t1/2 > 24 h). These findings increase our understanding of metabolism of Butyrophilin ligands and the structure–activity relationships of phosphonamidate prodrugs
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mixed aryl phosphonate prodrugs of a Butyrophilin ligand
2017Co-Authors: Benjamin J. Foust, Michael M. Poe, Chia-hung Christine Hsiao, Andrew J Wiemer, Nicholas A Lentini, David F. WiemerAbstract:Studies of aryl phosphonate derivatives of a Butyrophilin 3A1 ligand have resulted in identification of a potent stimulant of Vγ9 Vδ2 T cells. This compound, a mixed ester bearing one pivaloyloxymethyl substituent and one 1-naphthyl ester displayed an EC50 of 0.79 nM as a stimulant of T cell proliferation, and a 9.0 nM EC50 in an assay designed to measure interferon gamma production. In both assays, this is the most potent Butyrophilin ligand prodrug yet reported, and thus it should be a valuable tool for studies of T cell function. Furthermore, mixed aryl/acyloxyalkyl esters may represent a new class of phosphonate prodrugs with high efficacy.
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phosphinophosphonates and their tris pivaloyloxymethyl prodrugs reveal a negatively cooperative Butyrophilin activation mechanism
2017Co-Authors: Rebekah R. Shippy, Xiaochen Lin, Sherry S. Agabiti, Brendan M. Zangari, Benjamin J. Foust, Michael M. Poe, Chia-hung Christine Hsiao, Olga Vinogradova, David F. Wiemer, Andrew J WiemerAbstract:Butyrophilin 3A1 (BTN3A1) binds small phosphorus-containing molecules, which initiates transmembrane signaling and activates Butyrophilin-responsive cells. We synthesized several phosphinophosphonates and their corresponding tris-pivaloyloxymethyl (tris-POM) prodrugs and examined their effects on BTN3A1. An analog of (E)-4-hydroxy-3-methyl-but-2-enyl diphosphate (HMBPP) bound to BTN3A1 with intermediate affinity, which was enthalpy-driven. Docking studies revealed binding to the basic surface pocket and interactions between the allylic hydroxyl group and the BTN3A1 backbone. The phosphinophosphonate stimulated proliferation of Vγ9Vδ2 T cells with moderate activity (EC50 = 26 μM). Cellular potency was enhanced >600-fold in the tris-POM prodrug (EC50 = 0.041 μM). The novel prodrug also induced T cell mediated leukemia cell lysis. Analysis of dose–response data reveals HMBPP-induced Hill coefficients of 0.69 for target cell lysis and 0.68 in interferon secretion. Together, tris-POM prodrugs enhance the cellu...
Andrew J Wiemer - One of the best experts on this subject based on the ideXlab platform.
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structure activity relationships of Butyrophilin 3 ligands
2020Co-Authors: Andrew J WiemerAbstract:Phosphoantigens (pAgs) are small phosphorus-containing molecules that stimulate Vγ9Vδ2 T cells with sub-nanomolar cellular potency. Recent work has revealed that these compounds work through binding to the transmembrane immunoglobulin Butyrophilin 3A1 (BTN3A1) within its intracellular B30.2 domain. Engagement of BTN3A1 is critical to the formation of an immune synapse between cells that contain pAgs and the Vγ9Vδ2 T cells. This minireview summarizes the structure-activity relationships of pAgs and their implications to the mechanisms of Butyrophilin 3 activation leading to Vγ9Vδ2 T cell response.
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synthesis and bioactivity of the alanyl phosphonamidate stereoisomers derived from a Butyrophilin ligand
2019Co-Authors: Nicholas A Lentini, Chia-hung Christine Hsiao, Andrew J Wiemer, George B Crull, David F. WiemerAbstract:Aryloxy phosphonamidate derivatives of a Butyrophilin 3A1 ligand are stimulants of Vγ9 Vδ2 T cells. However, when bonded to an aryl ester and an amine, the phosphorus is stereogenic, and past compo...
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phosphonamidate prodrugs of a Butyrophilin ligand display plasma stability and potent vγ9 vδ2 t cell stimulation
2018Co-Authors: Nicholas A Lentini, Benjamin J. Foust, Chia-hung Christine Hsiao, Andrew J Wiemer, David F. WiemerAbstract:Small organophosphorus compounds stimulate Vγ9 Vδ2 T cells if they serve as ligands of Butyrophilin 3A1. Because the most potent natural ligand is ( E)-4-hydroxy-3-methyl-but-2-enyl diphosphate (HMBPP), which is the last intermediate in bacterial biosynthesis of isoprenoids that is not found in mammalian metabolism, activation of these T cells represents an important component of the immune response to bacterial infections. To identify Butyrophilin ligands that may have greater plasma stability, and clinical potential, we have prepared a set of aryl phosphonamidate derivatives (9a-i) of the natural ligand. Testing of these new compounds in assays of T cell response has revealed that this strategy can provide compounds with high potency for expansion of Vγ9 Vδ2 T cells (9f, EC50 = 340 pM) and interferon γ production in response to loaded K562 cells (9e, EC50 = 62 nM). Importantly, all compounds of this class display extended plasma stability ( t1/2 > 24 h). These findings increase our understanding of metabolism of Butyrophilin ligands and the structure-activity relationships of phosphonamidate prodrugs.
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Phosphonamidate Prodrugs of a Butyrophilin Ligand Display Plasma Stability and Potent Vγ9 Vδ2 T Cell Stimulation
2018Co-Authors: Nicholas A. Lentini, Benjamin J. Foust, Chia-hung Christine Hsiao, Andrew J Wiemer, David F. WiemerAbstract:Small organophosphorus compounds stimulate Vγ9 Vδ2 T cells if they serve as ligands of Butyrophilin 3A1. Because the most potent natural ligand is (E)-4-hydroxy-3-methyl-but-2-enyl diphosphate (HMBPP), which is the last intermediate in bacterial biosynthesis of isoprenoids that is not found in mammalian metabolism, activation of these T cells represents an important component of the immune response to bacterial infections. To identify Butyrophilin ligands that may have greater plasma stability, and clinical potential, we have prepared a set of aryl phosphonamidate derivatives (9a–i) of the natural ligand. Testing of these new compounds in assays of T cell response has revealed that this strategy can provide compounds with high potency for expansion of Vγ9 Vδ2 T cells (9f, EC50 = 340 pM) and interferon γ production in response to loaded K562 cells (9e, EC50 = 62 nM). Importantly, all compounds of this class display extended plasma stability (t1/2 > 24 h). These findings increase our understanding of metabolism of Butyrophilin ligands and the structure–activity relationships of phosphonamidate prodrugs
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mixed aryl phosphonate prodrugs of a Butyrophilin ligand
2017Co-Authors: Benjamin J. Foust, Michael M. Poe, Chia-hung Christine Hsiao, Andrew J Wiemer, Nicholas A Lentini, David F. WiemerAbstract:Studies of aryl phosphonate derivatives of a Butyrophilin 3A1 ligand have resulted in identification of a potent stimulant of Vγ9 Vδ2 T cells. This compound, a mixed ester bearing one pivaloyloxymethyl substituent and one 1-naphthyl ester displayed an EC50 of 0.79 nM as a stimulant of T cell proliferation, and a 9.0 nM EC50 in an assay designed to measure interferon gamma production. In both assays, this is the most potent Butyrophilin ligand prodrug yet reported, and thus it should be a valuable tool for studies of T cell function. Furthermore, mixed aryl/acyloxyalkyl esters may represent a new class of phosphonate prodrugs with high efficacy.
Tsukasa Matsuda - One of the best experts on this subject based on the ideXlab platform.
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stage specific expression of milk fat globule membrane glycoproteins in mouse mammary gland comparison of mfg e8 Butyrophilin and cd36 with a major milk protein β casein
1997Co-Authors: Naohito Aoki, Tetsuya Ishii, Takahiro Adachi, Ryo Nakamura, Sachiyo Ohira, Yumiko Yamaguchi, Mizue Negi, Tsukasa MatsudaAbstract:Abstract The expression of mouse milk fat globule membrane (MFGM) glycoproteins, MFG-E8, Butyrophilin, CD36 was analyzed by Northern blot analyses. MFG-E8 and Butyrophilin mRNAs were specifically detected in the mammary gland of lactating mice, whereas CD36 mRNA was detected in the heart and lung as well as in the mammary gland of lactating mice. The mRNAs of the three MFGM glycoproteins accumulated at mid-lactation were about 2–10-times as much as those of the early and late gestation stages, whereas β-casein mRNA accumulation was dramatically increased; the mRNA at mid-lactation was no less than 40-times as much as that before lactation. In mouse mammary epithelial cell lines, HC11 and COMMA-1D, only a slight or almost no enhancement for the expression of MFG-E8, Butyrophilin and CD36 mRNAs was induced simply by the treatment with the lactogenic hormones such as prolactin, insulin and dexamethasone, whereas the β-casein mRNA expression was remarkably enhanced only by that treatment. Furthermore, while the β-casein protein was constantly detected in milk throughout the lactation stage, the content of MFG-E8 and Butyrophilin proteins increased during the lactation with an increase in the milk fat content. These results suggest that the stage-specific expression of milk fat globule membrane glycoproteins in mammary epithelial cells is regulated in a similar but not necessarily identical mechanism to that of a major milk protein, β-casein.
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carboxy terminal cytoplasmic domain of mouse Butyrophilin specifically associates with a 150 kda protein of mammary epithelial cells and milk fat globule membrane
1995Co-Authors: Tetsuya Ishii, Naohito Aoki, Akihiro Noda, Takahiro Adachi, Ryo Nakamura, Tsukasa MatsudaAbstract:Abstract A cDNA encoding mouse Butyrophilin was obtained by reverse transcriptase-coupled polymerase chain reaction (RT-PCR) using poly (A)+ RNA from lactating mouse mammary gland as a template and screening a cDNA library with the RT-PCR-amplified fragment as a probe. DNA sequencing and computer analysis revealed that it has a rather long 3′-untranslated sequence and that the carboxy-terminal cytoplasmic domain was well conserved between mouse and bovine Butyrophilins. To elucidate the biological function of Butyrophilin, the cytoplasmic region expressed as fusion protein with glutathione S-transferase (GST) was purified and incubated with the cell lysate of mouse mammary epithelial cell lines, COMMA-ID and HC11. A 150-kDa protein was shown to specifically associate with the cytoplasmic domain and the protein increased in amount when the cells were treated with basal medium supplemented with lactogenic hormones such as prolactin, insulin and glucocorticoid. N-terminal amino acid sequencing indicated that the protein is xanthine dehydrogenase/oxidase which had been cloned from mouse liver. Further, the cytoplasmic domain also bound xanthine dehydrogenase/oxidase from bovine milk fat globule membrane. These results suggest that Butyrophilin might be physiologically associated with xanthine dehydrogenase/oxidase and might function in a complex form in milk fat secretion.
