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Armand Bensussan - One of the best experts on this subject based on the ideXlab platform.

  • CD160 soluble un nouveau mediateur de l echappement tumoral dans le melanome
    Annales De Dermatologie Et De Venereologie, 2018
    Co-Authors: Marielea Gauci, Jerome Giustiniani, Armand Bensussan, C Lepelletier, Martine Bagot, Celeste Lebbe, Nicolas Dumaz, Anne Mariecardine
    Abstract:

    Introduction L’immunotherapie a revolutionne la prise en charge du melanome aux stades avances. Cependant, certains patients developpent des resistances. Ceci est notamment lie a la capacite de la tumeur de rendre son environnement immunosuppresseur, favorisant ainsi son echappement au systeme immunitaire. CD160 est un recepteur unique exprime par les lymphocytes NK et T CD8+ cytotoxiques. Sa forme GPI (CD160-GPI) est impliquee dans la mise en place d’une activite cytotoxique. Au cours de l’activation lymphocytaire, cette forme est clivee et liberee sous une forme soluble (sCD160) presentant une fonction immunosuppressive sur les cellules cytotoxiques. Dans le meme temps une isoforme transmembranaire (CD160-TM) est exprimee dont l’engagement permet l’amplification de la reponse cytotoxique. Des marquages preliminaires realises sur des prelevements tumoraux de melanomes de patients (IHC) ont montre une positivite des tumeurs pour CD160. L’objectif du travail etait de valider l’expression de CD160 dans des lignees de melanome (MelC), de definir l’isoforme exprimee par les MelC et de determiner son role potentiel dans ce contexte tumoral. Materiel et methodes Une etude in vitro etait realisee a partir de lignees de melanome presentant differentes mutations (BRAF, NRAS ou NF1) et des melanocytes. L’etude par RT-PCR qualitative et quantitative, avec des amorces specifiques de CD160-TM et CD160-GPI permettait la determination de l’isoforme exprimee. L’expression proteique etait cherchee par Western Blot sur des lysats cellulaires. La localisation cellulaire de CD160 etait analysee par immunofluorescence en microscopie confocale et par une etude en cytometrie en flux realisee avec ou sans permeabilisation prealable des cellules. Enfin, les modulations de l’expression de CD160 etaient evaluees apres administration d’IFNγ. La forme soluble etait cherchee dans le milieu de culture cellulaire par immunoprecipitation. Resultats Nous avons observe une expression constitutive et exclusivement intracellulaire de CD160-GPI par les MelC. CD160-GPI n’etait pas detecte chez les melanocytes. De plus, nous avons mis en evidence une liberation constitutive de sCD160 dans l’environnement des cellules malignes qui peut etre augmentee en presence d’IFNγ pour certaines lignees, y compris celles n’exprimant pas PD-L1. Discussion La liberation de sCD160 par les MelC pourrait representer un mecanisme d’echappement de la tumeur a l’activite lymphocytaire anti-tumorale. En effet il a ete montre precedemment que sCD160 etait capable d’inhiber l’activite cytotoxique des lymphocytes NK et T CD8+ en entrant en competition avec les recepteurs activateurs de ces cellules pour la liaison aux molecules HLA. Conclusion Nous avons identifie un nouveau mecanisme d’echappement des MelC a l’immuno-surveillance, impliquant sCD160, qui pourrait representer une nouvelle cible therapeutique a l’ere de l’immunotherapie.

  • CD160 expression in retinal vessels is associated with retinal neovascular diseases
    Investigative Ophthalmology & Visual Science, 2018
    Co-Authors: Adrien Henry, Jerome Giustiniani, Camille Boulagnonrombi, Thierry Menguy, Christian Garbar, Corinne Mascaux, Marc Labrousse, Corentin Milas, Coralie Barbe, Armand Bensussan
    Abstract:

    Purpose Anti-angiogenic agents stand first in the treatment of neovascular diseases of the retina. CD160 appeared in several experimental studies as a marker of activated endothelial cells, suggesting it could represent a promising target for novel anti-angiogenic therapies. The aim of the present study was to assess the distribution of CD160 in the human eye, and to search for a possible correlation with retinal neovascular diseases. Methods The physiological distribution of CD160 in the normal eye was assessed with immunolabeling in 10 human donor eyes. Then, in a retrospective cohort of 75 surgical retinal specimens, the density of CD160+ microvessels was evaluated, along with immunolabeling on serial sections against ERG (pan-endothelial cell marker), CD105 (activated endothelial cell marker), and α-SMA (pericyte cell marker). The cohort was divided into two groups: 29 patients with neovascular disease (NV+) and 46 control patients (NV-). Results CD160 was physiologically expressed by several cell types: endothelial cells of retinal blood vessels, ganglion cells, macrophages, epithelial cells of the conjunctiva, ciliary body, and retinal pigment epithelium. In the patient cohort, the percentage of CD160+ vessels in the retina was significantly and independently higher in patients suffering from neovascular diseases (P = 0.04). On the contrary, the expression of CD105 was correlated neither with retinal neovascular diseases, nor with CD160 expression. Conclusions CD160 was expressed in some retinal vessels in both normal and pathologic eyes. CD160 expression by endothelial cells of retinal vessels was correlated with ocular neovascular diseases. CD160 could therefore represent an interesting target for novel anti-angiogenic therapies.

  • CD160: a unique activating NK cell receptor.
    Immunology Letters, 2011
    Co-Authors: Philippe Le Bouteiller, Jerome Giustiniani, Armand Bensussan, Beata Polgar, Julie Tabiasco, Noemi Kozma, Johan Siewiera, Alain Berrebi, Maryse Aguerre-girr, Nabila Jabrane-ferrat
    Abstract:

    Here we discuss CD160 an essential NK cell activating receptor that remains poorly understood. CD160 receptor exhibits a number of unique structural and functional characteristics that are not common to other killer immunoglobulin-like receptors that recognize major histocompatibility complex (MHC) class I molecules: (1) In addition to humans and mice, the CD160 gene is conserved in several other mammal species; (2) CD160 is located outside the NK gene complex and the Leukocyte Receptor Complex in humans; (3) CD160 expression is associated to the CD56(dim) CD16+ cytotoxic NK cell phenotype; (4) both human and mouse CD160 recognize MHC class Ia and Ib molecules; (5) unlike the other MHC class I-dependent activating NK receptors, CD160 is a glycosylphosphatidylinositol-anchored molecule with a single immunoglobulin-like domain, and does not bear immunoreceptor tyrosine-based activation motifs. Consequently, CD160 cannot signal by itself, requiring the recruitment of adaptor proteins. CD160 recruits phosphoinositide-3 kinase to trigger cytotoxicity and cytokine secretion; (6) specific engagement of NK CD160 receptor expressed by circulating NK cells produces proinflammatory cytokines IFN-γ, TNF-α, and, most notably, IL-6 and IL-8 as well as MIP1-β chemokine. The level of CD160-mediated IFN-γ production is always higher than the one observed after engagement of the CD16 receptor.

  • human and mouse mast cells express and secrete the gpi anchored isoform of CD160
    Journal of Investigative Dermatology, 2011
    Co-Authors: N Ortonne, Jerome Giustiniani, Anne Mariecardine, C Ramwolff, M Bagot, Salaheddine Mecheri, Armand Bensussan
    Abstract:

    CD160 is expressed by human and mouse natural killer (NK) cells and other cytotoxic lymphocyte subpopulations. CD160 is mostly expressed as a trimeric 83 kDa glycosylphosphatidylinositol (GPI)-anchored activating NK receptor, cleaved upon IL-15 stimulation in a secreted trimeric soluble form (sCD160) that binds to major histocompatibility complex (MHC) class I molecules, while a transmembrane isoform appears. sCD160 exhibits immunoregulatory function as it inhibits CD8+ T-lymphocyte cytotoxic activity. We show that human mast cells (MCs) express CD160. In human and mouse skin, resident MCs expressed CD160, whereas in C57BL/6-KitW-sh/W-sh mice, CD160+ cells were only identified at the site of reconstitution with syngeneic cultured MCs. In the human mast cell line, HMC-1, we only identified the transcripts of the GPI-anchored CD160 isoform. Furthermore, CD160 was identified in HMC-1 and mouse MC supernatants, suggesting that MCs release sCD160. Supporting this hypothesis, HMC-1 express the GPI-specific phospholipase D variant 2 involved in the NK lymphocyte membrane cleavage of CD160, and morphological studies highlighted a relative loss of CD160 expression in inflammatory skin sites, where MC degranulation is expected to occur. We also demonstrated an inhibition of T-cell cytotoxicity by HMC-1 supernatant that was partially reversed by anti-CD160 mAb. In conclusion, sCD160, produced by MCs, may have a role in T-cell–MC interactions in vivo.

  • CD160 signaling mediates pi3k dependent survival and growth signals in chronic lymphocytic leukemia
    Blood, 2010
    Co-Authors: Fengting Liu, Jerome Giustiniani, Armand Bensussan, Timothy Farren, Li Jia, John G Gribben, Samir G Agrawal
    Abstract:

    B-cell chronic lymphocytic leukemia (CLL) expresses CD160, a glycosylphosphatidylinositol-linked receptor found on normal natural killer (NK) and T cells, but not B cells. CD160 is a multifunctional molecule in normal lymphocytes, but its role in CLL biology is unknown. In vitro, CLL cells undergo rapid spontaneous apoptosis, which CD160 activation protected against—mean cell viability increased from 67% to 79% ( P < .001). This was associated with up-regulation of Bcl-2, Bcl-xL, and Mcl-1, but not Bax. As expected from these changes in Bcl-2/Bax and Bcl-xL/Bax ratios, CD160 triggering reduced mitochondrial membrane potential collapse and cytochrome c release. CD160 stimulation also induced DNA synthesis, cell cycle progression, and proliferation. B-cell antigen receptor (BCR)–induced CLL proliferation was generally greater than with CD160, but marked variation was seen. Both BCR and CD160 signaling led to CLL secretion of interleukin-6 (IL-6) and IL-8, although CD160 induced greater increases of IL-6 (51-fold) and IL-8 (15-fold). Survival and activation signals mediated by CD160 showed dose-dependent suppression by phosphoinositide-3 kinase (PI3K) inhibitors. Thus, in vitro, CLL cells can use the CD160 pathway for survival and activation, mimicking CD160 signaling in normal NK and CD8+ T cells. Establishing the pathophysiologic relevance of these findings may reveal new therapeutic targets.

Jerome Giustiniani - One of the best experts on this subject based on the ideXlab platform.

  • CD160 soluble un nouveau mediateur de l echappement tumoral dans le melanome
    Annales De Dermatologie Et De Venereologie, 2018
    Co-Authors: Marielea Gauci, Jerome Giustiniani, Armand Bensussan, C Lepelletier, Martine Bagot, Celeste Lebbe, Nicolas Dumaz, Anne Mariecardine
    Abstract:

    Introduction L’immunotherapie a revolutionne la prise en charge du melanome aux stades avances. Cependant, certains patients developpent des resistances. Ceci est notamment lie a la capacite de la tumeur de rendre son environnement immunosuppresseur, favorisant ainsi son echappement au systeme immunitaire. CD160 est un recepteur unique exprime par les lymphocytes NK et T CD8+ cytotoxiques. Sa forme GPI (CD160-GPI) est impliquee dans la mise en place d’une activite cytotoxique. Au cours de l’activation lymphocytaire, cette forme est clivee et liberee sous une forme soluble (sCD160) presentant une fonction immunosuppressive sur les cellules cytotoxiques. Dans le meme temps une isoforme transmembranaire (CD160-TM) est exprimee dont l’engagement permet l’amplification de la reponse cytotoxique. Des marquages preliminaires realises sur des prelevements tumoraux de melanomes de patients (IHC) ont montre une positivite des tumeurs pour CD160. L’objectif du travail etait de valider l’expression de CD160 dans des lignees de melanome (MelC), de definir l’isoforme exprimee par les MelC et de determiner son role potentiel dans ce contexte tumoral. Materiel et methodes Une etude in vitro etait realisee a partir de lignees de melanome presentant differentes mutations (BRAF, NRAS ou NF1) et des melanocytes. L’etude par RT-PCR qualitative et quantitative, avec des amorces specifiques de CD160-TM et CD160-GPI permettait la determination de l’isoforme exprimee. L’expression proteique etait cherchee par Western Blot sur des lysats cellulaires. La localisation cellulaire de CD160 etait analysee par immunofluorescence en microscopie confocale et par une etude en cytometrie en flux realisee avec ou sans permeabilisation prealable des cellules. Enfin, les modulations de l’expression de CD160 etaient evaluees apres administration d’IFNγ. La forme soluble etait cherchee dans le milieu de culture cellulaire par immunoprecipitation. Resultats Nous avons observe une expression constitutive et exclusivement intracellulaire de CD160-GPI par les MelC. CD160-GPI n’etait pas detecte chez les melanocytes. De plus, nous avons mis en evidence une liberation constitutive de sCD160 dans l’environnement des cellules malignes qui peut etre augmentee en presence d’IFNγ pour certaines lignees, y compris celles n’exprimant pas PD-L1. Discussion La liberation de sCD160 par les MelC pourrait representer un mecanisme d’echappement de la tumeur a l’activite lymphocytaire anti-tumorale. En effet il a ete montre precedemment que sCD160 etait capable d’inhiber l’activite cytotoxique des lymphocytes NK et T CD8+ en entrant en competition avec les recepteurs activateurs de ces cellules pour la liaison aux molecules HLA. Conclusion Nous avons identifie un nouveau mecanisme d’echappement des MelC a l’immuno-surveillance, impliquant sCD160, qui pourrait representer une nouvelle cible therapeutique a l’ere de l’immunotherapie.

  • CD160 expression in retinal vessels is associated with retinal neovascular diseases
    Investigative Ophthalmology & Visual Science, 2018
    Co-Authors: Adrien Henry, Jerome Giustiniani, Camille Boulagnonrombi, Thierry Menguy, Christian Garbar, Corinne Mascaux, Marc Labrousse, Corentin Milas, Coralie Barbe, Armand Bensussan
    Abstract:

    Purpose Anti-angiogenic agents stand first in the treatment of neovascular diseases of the retina. CD160 appeared in several experimental studies as a marker of activated endothelial cells, suggesting it could represent a promising target for novel anti-angiogenic therapies. The aim of the present study was to assess the distribution of CD160 in the human eye, and to search for a possible correlation with retinal neovascular diseases. Methods The physiological distribution of CD160 in the normal eye was assessed with immunolabeling in 10 human donor eyes. Then, in a retrospective cohort of 75 surgical retinal specimens, the density of CD160+ microvessels was evaluated, along with immunolabeling on serial sections against ERG (pan-endothelial cell marker), CD105 (activated endothelial cell marker), and α-SMA (pericyte cell marker). The cohort was divided into two groups: 29 patients with neovascular disease (NV+) and 46 control patients (NV-). Results CD160 was physiologically expressed by several cell types: endothelial cells of retinal blood vessels, ganglion cells, macrophages, epithelial cells of the conjunctiva, ciliary body, and retinal pigment epithelium. In the patient cohort, the percentage of CD160+ vessels in the retina was significantly and independently higher in patients suffering from neovascular diseases (P = 0.04). On the contrary, the expression of CD105 was correlated neither with retinal neovascular diseases, nor with CD160 expression. Conclusions CD160 was expressed in some retinal vessels in both normal and pathologic eyes. CD160 expression by endothelial cells of retinal vessels was correlated with ocular neovascular diseases. CD160 could therefore represent an interesting target for novel anti-angiogenic therapies.

  • possible pathogenic role of the transmembrane isoform of CD160 nk lymphocyte receptor in paroxysmal nocturnal hemoglobinuria
    Current Molecular Medicine, 2012
    Co-Authors: Jerome Giustiniani, Daniel Olive, S Sabouralaoui, J Bernard, C Bos, A Razafindratsita, Anna D Petropoulou, R P De Latour, Le P Bouteiller, M Bagot
    Abstract:

    PIGA mutations in paroxysmal nocturnal hemoglobinuria (PNH) patients lead to a glycosylphosphatidylinositol (GPI)-linked membrane proteins expression deficiency. Herein, we report the constitutive expression of the transmembrane CD160 (CD160-TM) activating receptor on non PIGA-mutated PNH patients circulating NK cells. In healthy individuals, only the GPI-anchored isoform of CD160 receptors is expressed on the circulating NK lymphocytes, while the transmembrane isoform appears after ex vivo activation. Similarly to CD160-GPI, we identified CD160-TM as a receptor for the MHC class I molecules. We demonstrate that PNH patients NK lymphocytes spontaneously produce significant amounts of IFN-γ that is inhibited by anti-CD160-TM or anti-MHC class I mAbs. These results indicate that circulating NK cells from PNH patients exhibit a self-MHC class I molecule reactive effector function, which could be mediated through the recruitment of CD160-TM receptor. Our data provide new insights regarding the possible role of CD160-TM on PNH patients NK lymphocytes and in the pathogenesis of the disease

  • CD160: a unique activating NK cell receptor.
    Immunology Letters, 2011
    Co-Authors: Philippe Le Bouteiller, Jerome Giustiniani, Armand Bensussan, Beata Polgar, Julie Tabiasco, Noemi Kozma, Johan Siewiera, Alain Berrebi, Maryse Aguerre-girr, Nabila Jabrane-ferrat
    Abstract:

    Here we discuss CD160 an essential NK cell activating receptor that remains poorly understood. CD160 receptor exhibits a number of unique structural and functional characteristics that are not common to other killer immunoglobulin-like receptors that recognize major histocompatibility complex (MHC) class I molecules: (1) In addition to humans and mice, the CD160 gene is conserved in several other mammal species; (2) CD160 is located outside the NK gene complex and the Leukocyte Receptor Complex in humans; (3) CD160 expression is associated to the CD56(dim) CD16+ cytotoxic NK cell phenotype; (4) both human and mouse CD160 recognize MHC class Ia and Ib molecules; (5) unlike the other MHC class I-dependent activating NK receptors, CD160 is a glycosylphosphatidylinositol-anchored molecule with a single immunoglobulin-like domain, and does not bear immunoreceptor tyrosine-based activation motifs. Consequently, CD160 cannot signal by itself, requiring the recruitment of adaptor proteins. CD160 recruits phosphoinositide-3 kinase to trigger cytotoxicity and cytokine secretion; (6) specific engagement of NK CD160 receptor expressed by circulating NK cells produces proinflammatory cytokines IFN-γ, TNF-α, and, most notably, IL-6 and IL-8 as well as MIP1-β chemokine. The level of CD160-mediated IFN-γ production is always higher than the one observed after engagement of the CD16 receptor.

  • differential and tumor specific expression of CD160 in b cell malignancies
    Blood, 2011
    Co-Authors: Timothy Farren, Jerome Giustiniani, Fengting Liu, Adrian C Newland, M G Macey, Dimitris A Tsitsikas, J Cavenagh, Heather Oakervee, David Taussig, Maria Calaminici
    Abstract:

    CD160 is a human natural killer (NK)-cell–activating receptor that is also expressed on T-cell subsets. In the present study, we examined 811 consecutive cases of B-cell lymphoproliferative disorders (B-LPDs), and demonstrated CD160 expression in 98% (590 of 600) of chronic lymphocytic leukemia (CLL) cases, 100% (32 of 32) of hairy cell leukemia (HCL) cases, 15% (5 of 34) of mantle cell lymphoma (MCL) in the leukemic phase, and 16% (23 of 145) of other B-LPD cases. CD160 transcript and protein were absent in the normal B-cell hierarchy, from stem cells, B-cell precursors, maturing B cells in the germinal center, and circulating B cells, including CD5+CD19+ B1 cells in umbilical cord. CD160 positivity was significantly higher in CLL and HCL in terms of percentage (65.9% and 67.8%, respectively, P < .0001) and median fluorescence intensity (552 and 857, respectively, P < .0001) compared with all other B-LPD cases. Lymph node CLL samples were also CD160+. Using the disease-specific expression of CD5, CD23, and CD160, a score of 3 characterized CLL (diagnostic odds ratio, 1430); a score of 0 excluded CLL, MCL, and HCL; and the CD23/CD5 ratio differentiated CLL from leukemic CD23+ MCL. In the B-cell lineage, CD160 is a tumor-specific antigen known to mediate cellular activation signals in CLL, and is a novel target for therapeutic manipulation and monitoring of minimal residual disease.

Adam W Barb - One of the best experts on this subject based on the ideXlab platform.

  • a single amino acid distorts the fc γ receptor iiib cd16b structure upon binding immunoglobulin g1 and reduces affinity relative to cd16a
    Journal of Biological Chemistry, 2018
    Co-Authors: Jacob T Roberts, Adam W Barb
    Abstract:

    Therapeutic mAbs engage Fc γ receptor III (CD16) to elicit a protective cell-mediated response and destroy the target tissue. Newer drugs designed to bind CD16a with increased affinity surprisingly also elicit protective CD16b-mediated responses. However, it is unclear why IgG binds CD16a with more than 10-fold higher affinity than CD16b even though these receptors share more than 97% identity. Here we identified one residue, Gly-129, that contributes to the greater IgG binding affinity of CD16a. The CD16b variant D129G bound IgG1 Fc with 2-fold higher affinity than CD16a and with 90-fold higher affinity than the WT. Conversely, the binding affinity of CD16a-G129D was decreased 128-fold relative to WT CD16a and comparably to that of WT CD16b. The interaction of IgG1 Fc with CD16a, but not with CD16b, is known to be sensitive to the composition of the asparagine-linked carbohydrates (N-glycans) attached to the receptor. CD16a and CD16b-D129G displaying minimally processed oligomannose N-glycans bound to IgG1 Fc with about 5.2-fold increased affinity compared with variants with highly processed complex-type N-glycans. CD16b and the CD16a-G129D variant exhibited a smaller 1.9-fold affinity increase with oligomannose N-glycans. A model of glycosylated CD16b bound to IgG1 Fc determined to 2.2 A resolution combined with a 250-ns all-atom molecular dynamics simulation showed that the larger Asp-129 residue deformed the Fc-binding surface. These results reveal how Asp-129 in CD16b affects its binding affinity for IgG1 Fc and suggest that antibodies engineered to engage CD16b with high affinity must accommodate the Asp-129 side chain.

  • cd16a with oligomannose type n glycans is the only low affinity fc γ receptor that binds the igg crystallizable fragment with high affinity in vitro
    Journal of Biological Chemistry, 2018
    Co-Authors: Ganesh P Subedi, Adam W Barb
    Abstract:

    Fc γ receptors (FcγRs) bind circulating IgG (IgG1) at the surface of leukocytes. Antibodies clustered at the surface of a targeted particle trigger a protective immune response through activating FcγRs. Three recent reports indicate that the composition of the asparagine-linked carbohydrate chains (N-glycans) of FcγRIIIa/CD16a impacted IgG1-binding affinity. Here we determined how N-glycan composition affected the affinity of the "low-affinity" FcγRs for six homogeneous IgG1 Fc N-glycoforms (G0, G0F, G2, G2F, A2G2, and A2G2F). Surprisingly, CD16a with oligomannose N-glycans bound to IgG1 Fc (A2G2) with a KD = 1.0 ± 0.1 nm This affinity represents a 51-fold increase over the affinity measured for CD16a with complex-type N-glycans (51 ± 8 nm) and is comparable with the affinity of FcγRI/CD64, the sole "high-affinity" FcγR. CD16a N-glycan composition accounted for increases in binding affinity for the other IgG1 Fc glycoforms tested (10-50-fold). This remarkable sensitivity could only be eliminated by preventing glycosylation at Asn162 with an Asn-to-Gln mutation; mutations at the four other N-glycosylation sites preserved tighter binding in the Man5 glycoform. None of the other low-affinity FcγRs showed more than a 3.1-fold increase upon modifying the receptor N-glycan composition, including CD16b, which differs from CD16a by only four amino acid residues. This result indicates that CD16a is unique among the low-affinity FcγRs, and modifying only the glycan composition of both the IgG1 Fc ligand and receptor provides a 400-fold range in affinities.

  • the immunoglobulin g1 n glycan composition affects binding to each low affinity fc γ receptor
    mAbs, 2016
    Co-Authors: Ganesh P Subedi, Adam W Barb
    Abstract:

    ABSTRACTImmunoglobulin G1 (IgG1) is the most abundant circulating human antibody and also the scaffold for many therapeutic monoclonal antibodies (mAbs). The destruction of IgG-coated targets by cell-mediated pathways begins with an interaction between the IgG Fc region and multiple varieties of membrane-bound Fc γ receptors (FcγRs) on the surface of leukocytes. This interaction requires the presence of an asparagine-linked (N-)glycan on the Fc, and variations in the N-glycan composition can affect the affinity of CD16A binding (an FcγR). Contemporary efforts to glycoengineer mAbs focus on increasing CD16A affinity, and thus treatment efficacy, but it is unclear how these changes affect affinity for the other FcγRs. Here, we measure binding of the extracellular Fc-binding domains for human CD16A and B, CD32A, B and C, and CD64 to 6 well-defined IgG1 Fc glycoforms that cover ∼85% of the pool of human IgG1 Fc glycoforms. Core α1–6 fucosylation showed the greatest changes with CD16B (8.5-fold decrease), CD16...

Philippe Le Bouteiller - One of the best experts on this subject based on the ideXlab platform.

  • CD160 activating nk cell effector functions depend on the phosphatidylinositol 3 kinase recruitment
    International Immunology, 2007
    Co-Authors: Magali Rabot, Armand Bensussan, Anne Mariecardine, Aliz Barakonyi, Maryse Aguerregirr, Beata Polgar, Hicham El Costa, Salvatore Valitutti, Philippe Le Bouteiller
    Abstract:

    CD160 NK cell-activating receptor is a glycosyl-phosphatidylinositol-anchored molecule that, upon specific engagement, triggers both cytotoxicity and a unique cytokine production [IFN-g, tumor necrosis factor-a (TNF-a) and IL-6] through an undefined signaling pathway. In the current study, we have identified several signaling molecules recruited after mAb-specific CD160 engagement in freshly isolated human circulating NK cells. Using confocal microscopy, we found that CD160 engagement induces the recruitment and co-localization of phosphorylated molecules with redistributed, capped CD160 at the cell surface. We then demonstrated that phosphatidylinositol 3-kinase (PI3K) signaling molecule is required for CD160-mediated cytotoxicity and cytokine release. First, we observed by confocal microscopy that engagement of CD160 induces its polarization and co-localization with PI3K. Second, we showed that pharmacological inhibitors of PI3K abrogate both CD160-mediated cytotoxicity and IFN-g, TNF-a and IL-6 cytokine release. We further found that CD160 engagement induced marked phosphorylation of Akt, as evidenced by western blotting. We identified additional CD160-mediated signaling molecules recruited downstream and upstream of PI3K. Both induction of phosphorylated ERK molecules after CD160-specific engagement and prevention of CD160-induced cytokine release by MEK pharmacological inhibitor indicate that ERK downstream pathway is implicated. Similarly, we identified that Syk molecule upstream of PI3K is involved in the signaling cascade mediated by CD160 engagement. Two different Syk-specific inhibitors blocked CD160mediated cytokine release, and CD160-specific engagement induced the enhancement of phosphorylated Syk proteins. These data demonstrate that PI3K is a crucial signaling element for both effector functions of the CD160 NK cell-activating receptor.

  • engagement of the CD160 activating nk cell receptor leads to its association with cd2 in circulating human nk cells
    Transplant Immunology, 2006
    Co-Authors: Magali Rabot, Armand Bensussan, Philippe Le Bouteiller
    Abstract:

    CD160 activating NK cell receptor is a glycosylphosphatidylinositol-anchored molecule. Upon specific engagement by its HLA class I physiological ligand, CD160 NK cell receptor triggers cytotoxicity and release of different cytokines, including IL-6. How CD160 intracellular signaling is mediated following its specific ligation is unknown. One key element of this signaling may be through the co-activation of other receptors associated to CD160. Using confocal microscopy and freshly isolated human peripheral blood NK cells, we observed a co-polarization of CD160 and CD2 after their respective specific engagement. These results demonstrate that CD160 activating NK cell receptor, upon its specific engagement, physically associates to the CD2 co-activating receptor present in the lipid raft that might play a role as signaling molecule.

  • cutting edge engagement of CD160 by its hla c physiological ligand triggers a unique cytokine profile secretion in the cytotoxic peripheral blood nk cell subset
    Journal of Immunology, 2004
    Co-Authors: Aliz Barakonyi, Valerie Schiavon, Armand Bensussan, Anne Mariecardine, Magali Rabot, Maryse Aguerregirr, Beata Polgar, Philippe Le Bouteiller
    Abstract:

    CD160 is an Ig-like activating NK cell receptor expressed on the majority of circulating NK cells. This population corresponds to the nonproliferating, highly cytolytic, CD56 dim CD16 + subset. CD160 engagement by HLA-C molecules mediates cytotoxic function. In this study, we report that upon specific activation by the physiological ligand HLA-C, or Ab cross-linking, CD160 + peripheral blood NK cells produce IFN-γ, TNF-α, and IL-6. This unique CD160-mediated cytokine production differs from the one observed after CD16 engagement whose expression is also restricted to the CD56 dim cytotoxic NK cell subset. As already reported for the CD160-mediated cytotoxic effector function, CD160-mediated cytokine production by peripheral blood-NK cells is negatively controlled by the killer Ig-like receptor CD158b. Thus, the CD160 receptor represents a unique triggering surface molecule expressed by cytotoxic NK cells that participates in the inflammatory response and determines the type of subsequent specific immunity.

  • engagement of CD160 receptor by hla c is a triggering mechanism used by circulating natural killer nk cells to mediate cytotoxicity
    Proceedings of the National Academy of Sciences of the United States of America, 2002
    Co-Authors: Philippe Le Bouteiller, Jerome Giustiniani, Anne Mariecardine, Aliz Barakonyi, Magali Rabot, Maryse Aguerregirr, Francoise Lenfant, I Hilgert, Fathia Mamichouaib, Julie Tabiasco
    Abstract:

    Circulating human natural killer (NK) lymphocytes have been functionally defined by their ability to exert cytotoxic activity against MHC class I-negative target cell lines, including K562. Therefore, it was proposed that NK cells recognized the “missing self.” We show here that the Ig-like CD160 receptor expressed by circulating CD56dim+ NK cells or IL-2-deprived NK cell lines is mainly involved in their cytotoxic activity against K562 target cells. Further, we report that HLA-C molecules that are constitutively expressed by K562 trigger NK cell lysis through CD160 receptor engagement. In addition, we demonstrate, with recombinant soluble HLA-Cw3 and CD160 proteins, direct interaction of these molecules. We also find that CD158b inhibitory receptors partially interfere with CD160-mediated cytotoxicity, whereas CD94/CD159a and CD85j have no effect on engagement with their respective ligands. Thus, CD160/HLA-C interaction constitutes a unique pathway to trigger NK cell cytotoxic activity.

Sharon R. Lewin - One of the best experts on this subject based on the ideXlab platform.

  • Differential expression of CD163 on monocyte subsets in healthy and HIV-1 infected individuals.
    PLOS ONE, 2011
    Co-Authors: Emma Dawn Tippett, Wan-jung Cheng, Paul U. Cameron, Anthony Jaworowski, Bruce J Brew, Clare L V Westhorpe, Sharon R. Lewin, Suzanne M Crowe
    Abstract:

    CD163, a haptoglobin-hemoglobin (Hp-Hb) scavenger receptor, expressed by monocytes and macrophages, is important in resolution of inflammation. Age-related non-AIDS co-morbidities in HIV-infected individuals, particularly dementia and cardiovascular disease, result in part from effects of HIV-1 infection on monocyte and macrophage biology. CD163 co-expression on CD14+CD16++ monocytes has been proposed as a useful biomarker for HIV-1 disease progression and the presence of HIV associated dementia. Here we investigated CD163 expression on monocyte subsets ex vivo, on cultured macrophages, and soluble in plasma, in the setting of HIV-1 infection. Whole blood immunophenotyping revealed CD163 expression on CD14++CD16- monocytes but not on CD14+CD16++ monocytes (P = 0.004), supported by CD163 mRNA levels. Incubation with M-CSF induced CD163 protein expression on CD14+CD16++ monocytes to the same extent as CD14++CD16− monocytes. CD163 expression on CD14++CD16+ monocytes from HIV-infected subjects was significantly higher than from uninfected individuals, with a trend towards increased expression on CD14++CD16− monocytes (P = 0.019 and 0.069 respectively), which is accounted for by HIV-1 therapy including protease inhibitors. Shedding of CD163 was shown to predominantly occur from the CD14++CD16− subset after Ficoll isolation and LPS stimulation. Soluble CD163 concentration in plasma from HIV-1 infected donors was similar to HIV-1 uninfected donors. Monocyte CD163 expression in HIV-1 infected patients showed a complicated relationship with classical measures of disease progression. Our findings clarify technical issues regarding CD163 expression on monocyte subsets and further elucidates its role in HIV-associated inflammation by demonstrating that CD163 is readily lost from CD14++CD16− monocytes and induced in pro-inflammatory CD14+CD16++ monocytes by M-CSF. Our data show that all monocyte subsets are potentially capable of differentiating into CD163-expressing anti-inflammatory macrophages given appropriate stimuli. Levels of CD163 expression on monocytes may be a potential biomarker reflecting efforts by the immune system to resolve immune activation and inflammation in HIV-infected individuals.

  • hiv inhibits early signal transduction events triggered by cd16 cross linking on nk cells which are important for antibody dependent cellular cytotoxicity
    Journal of Leukocyte Biology, 2011
    Co-Authors: Wan-jung Cheng, Paul U. Cameron, Sharon R. Lewin, Gregor F Lichtfuss, Aislin C Meehan
    Abstract:

    Measurement of NK cell cytolytic activity in the setting of chronic viral infection is important for determining viral pathogenicity. Mobilization of LAMP-1 (CD107a) to the NK cell surface is a surrogate marker for cytotoxic granule release and hence, NK cell cytotoxicity. We have developed a convenient, rapid, whole blood flow cytometric assay for measuring CD107a mobilization in response to CD16 cross-linking, a surrogate for NK cell ADCC activity ex vivo, which can be performed using small volumes of patient whole blood. Using this assay, we show that CD107a mobilization, in response to CD16 cross-linking, is triggered in CD56 dim but not CD56 bright NK cells, requiring Syk/Zap70 tyrosine kinase activity, and that there is a significant correlation between CD107a mobilization and pSyk/Zap70 in response to CD16 cross-linking. We compared whole blood from treatment-naive, HIV-infected patients with age- and sex-matched HIV-uninfected control subjects and found a significant reduction in CD16-dependent pSyk/Zap70 (median=32.7% compared with 67.8%; P=0.0002) and CD107a mobilization (median=9.72% compared with 32.9%; P=0.046) in NK cells. Reduction of both correlated strongly with reduced CD16 surface expression on NK cells of HIV-infected individuals (P < 0.01). These data suggest that ADCC is inhibited in NK cells from therapy-naive, HIV-infected individuals at the level of early events in CD16 signal transduction, associated with low CD16R expression, and our method is a useful and reliable tool to detect pathological defects in NK cell degranulation. © Society for Leukocyte Biology.