The Experts below are selected from a list of 3810 Experts worldwide ranked by ideXlab platform
Gregory Beck - One of the best experts on this subject based on the ideXlab platform.
-
generation of monoclonal antibodies to Coelomocytes of the purple sea urchin arbacia punctulata characterization and phenotyping
Developmental and Comparative Immunology, 2007Co-Authors: Suzanne Grant, Gregory BeckAbstract:Cellular cytotoxicity is a key component of animal innate immune responses that is one of the first lines of defense against invaders. There is increasing interest in the study of the cellular immune response, particularly non-specific cytotoxic cells and natural killer cells and their receptors. Studies of non-specific cytotoxic cell and natural killer cell recognition and killing (and the receptors involved) will reveal new and important insights into cellular mechanisms of host defense. Here we describe mAbs specific for Coelomocyte sub-populations of the purple sea urchin, Arbacia punctulata, using highly purified Coelomocyte populations as the antigen source. Monoclonal antibodies were selected using flow cytometric screening methods. Several of the mAbs were shown to bind to two sub-types of Coelomocytes when assayed by fluorescence microscopy. Furthermore, these mAbs inhibited Coelomocyte cytotoxicity against vertebrate target cells in a functional assay. The mAbs have been used in immunoprecipitation studies.
-
phylogeny of natural cytotoxicity cytotoxic activity of Coelomocytes of the purple sea urchin arbacia punctulata
Journal of Experimental Zoology, 2001Co-Authors: Haiyan Zhang, Gregory BeckAbstract:Coelomocyte-mediated nonspecific cell cytotoxic activity against human and mu- rine target cells by the purple sea urchin Arbacia punctulata was investigated in vitro. Cytotoxic activity toward target cells was shown to be mediated by different Coelomocyte populations iso- lated by discontinuous density gradient centrifugation. The population of phagocytic amebocytes showed the strongest cytotoxic activity and the highest binding to human NK markers by cytometry analysis. Our immunophenotypic studies showed that A. punctulata phagocytic amebocytes are CD14 + , CD56 + , CD158b + , CD3 - , CD4 - , CD8 - , and CD16 - . The cytotoxic activity was independent of experimental incubation temperatures, required viable effector cells, and required cell-cell contact between the effector and target cells. Sodium azide significantly decreased Coelomocyte cytotoxic- ity, indicating that cytotoxicity is metabolically dependent, and EDTA reduction of cytotoxic activ- ity is consistent with the involvement of divalent cations in the cytotoxic process. These data describe a population of sea urchin Coelomocytes (the phagocytic amebocyte) that are CD14 + , CD56 + , and CD158b + , with cytotoxic activities. J. Exp. Zool. 290:741-750, 2001. © 2001 Wiley-Liss, Inc.
Hugo Aguilaniu - One of the best experts on this subject based on the ideXlab platform.
-
Coelomocytes regulate starvation-induced fat catabolism and lifespan extension through the lipase LIPL-5 in Caenorhabditis elegans
Cell Reports, 2019Co-Authors: Alexia Buis, Stéphanie Bellemin, Jérôme Goudeau, Léa Monnier, Nicolas Loiseau, Hervé Guillou, Hugo AguilaniuAbstract:Dietary restriction is known to extend the lifespan and reduce fat stores in most species tested to date, but the molecular mechanisms linking these events remain unclear. Here, we found that bacterial deprivation of Caenorhabditis elegans leads to lifespan extension with concomitant mobilization of fat stores. We find that LIPL-5 expression is induced by starvation and that the LIPL-5 lipase is present in Coelomocyte cells and regulates fat catabolism and longevity during the bacterial deprivation response. Either LIPL-5 or Coelomocyte deficiency prevents the rapid mobilization of intestinal triacylglycerol and enhanced lifespan extension in response to bacterial deprivation, whereas the combination of both defects has no additional or synergistic effect. Thus, the capacity to mobilize fat via LIPL-5 is directly linked to an animal's capacity to withstand long-term nutrient deprivation. Our data establish a role for LIPL-5 and Coelomocytes in regulating fat consumption and lifespan extension upon DR.
Edward M. Bonder - One of the best experts on this subject based on the ideXlab platform.
-
Identification of Coelomocyte unconventional myosin and its association with in vivo particle/vesicle motility
Journal of Cell Science, 1994Co-Authors: L. D'andrea, M.a. Danon, G.p. Sgourdas, Edward M. BonderAbstract:Sea urchin Coelomocytes undergo an inducible structural transformation from petalloid to filopodial form during the ‘clotting’ response in sea urchins. Using a petalloid Coelomocyte model, stimulated Coelomocytes exhibited bidirectional particle/vesicle motility with a broad distribution of velocities, ranging from 0.02 to 0.12 microns s-1 in the outward bound direction. Coelomocytes treated with the microtubule-disrupting drug, nocodazole, continued to exhibit outward particle/vesicle movements along linear paths with an average velocity of 0.028 +/- 0.006 microns s-1. We partially purified a 110 kDa polypeptide possessing K+EDTA-, Ca2(+)-, Mg2(+)- and F-actin-activated Mg(2+)-ATPase activities characteristic of myosin-like motor proteins. The 110 kDa protein immuno-crossreacted with both affinity-purified, anti-brush border unconventional myosin-I polyclonal antibodies and anti-Acanthamoeba myosin head monoclonal antibodies. By indirect immunofluorescence, the 110 kDa unconventional myosin was localized to clusters of particles/vesicles within the perinuclear region of unstimulated Coelomocytes, an area containing numerous mitochondria, acidic, lysosomal and Golgi organelles. Indirect immunofluorescence of partially transformed and filopodial Coelomocytes detected a diminution of perinuclear staining with a concomitant appearance of stained linear arrays of particles/vesicles, enhanced staining of peripheral lamellae, and staining of the entire length of the filopodia. Subfractionation of unstimulated Coelomocyte homogenates on linear sucrose gradients identified distinct peaks of ATPase activity associated with fractions containing conventional and 110 kDa unconventional myosin. Unconventional myosin-containing fractions were found to have numerous particles that stained with anti-brush border unconventional myosin-I antibodies and the lipophilic dye, DiOC6. Thus, Coelomocytes demonstrate activatable movements of particles/vesicles in cells devoid of microtubules and possess an unconventional myosin, which may be the motor protein driving particle/vesicle translocation.
-
identification of Coelomocyte unconventional myosin and its association with in vivo particle vesicle motility
Journal of Cell Science, 1994Co-Authors: L Dandrea, M.a. Danon, G.p. Sgourdas, Edward M. BonderAbstract:Sea urchin Coelomocytes undergo an inducible structural transformation from petalloid to filopodial form during the ‘clotting’ response in sea urchins. Using a petalloid Coelomocyte model, stimulated Coelomocytes exhibited bidirectional particle/vesicle motility with a broad distribution of velocities, ranging from 0.02 to 0.12 microns s-1 in the outward bound direction. Coelomocytes treated with the microtubule-disrupting drug, nocodazole, continued to exhibit outward particle/vesicle movements along linear paths with an average velocity of 0.028 +/- 0.006 microns s-1. We partially purified a 110 kDa polypeptide possessing K+EDTA-, Ca2(+)-, Mg2(+)- and F-actin-activated Mg(2+)-ATPase activities characteristic of myosin-like motor proteins. The 110 kDa protein immuno-crossreacted with both affinity-purified, anti-brush border unconventional myosin-I polyclonal antibodies and anti-Acanthamoeba myosin head monoclonal antibodies. By indirect immunofluorescence, the 110 kDa unconventional myosin was localized to clusters of particles/vesicles within the perinuclear region of unstimulated Coelomocytes, an area containing numerous mitochondria, acidic, lysosomal and Golgi organelles. Indirect immunofluorescence of partially transformed and filopodial Coelomocytes detected a diminution of perinuclear staining with a concomitant appearance of stained linear arrays of particles/vesicles, enhanced staining of peripheral lamellae, and staining of the entire length of the filopodia. Subfractionation of unstimulated Coelomocyte homogenates on linear sucrose gradients identified distinct peaks of ATPase activity associated with fractions containing conventional and 110 kDa unconventional myosin. Unconventional myosin-containing fractions were found to have numerous particles that stained with anti-brush border unconventional myosin-I antibodies and the lipophilic dye, DiOC6. Thus, Coelomocytes demonstrate activatable movements of particles/vesicles in cells devoid of microtubules and possess an unconventional myosin, which may be the motor protein driving particle/vesicle translocation.
Alexia Buis - One of the best experts on this subject based on the ideXlab platform.
-
Coelomocytes regulate starvation-induced fat catabolism and lifespan extension through the lipase LIPL-5 in Caenorhabditis elegans
Cell Reports, 2019Co-Authors: Alexia Buis, Stéphanie Bellemin, Jérôme Goudeau, Léa Monnier, Nicolas Loiseau, Hervé Guillou, Hugo AguilaniuAbstract:Dietary restriction is known to extend the lifespan and reduce fat stores in most species tested to date, but the molecular mechanisms linking these events remain unclear. Here, we found that bacterial deprivation of Caenorhabditis elegans leads to lifespan extension with concomitant mobilization of fat stores. We find that LIPL-5 expression is induced by starvation and that the LIPL-5 lipase is present in Coelomocyte cells and regulates fat catabolism and longevity during the bacterial deprivation response. Either LIPL-5 or Coelomocyte deficiency prevents the rapid mobilization of intestinal triacylglycerol and enhanced lifespan extension in response to bacterial deprivation, whereas the combination of both defects has no additional or synergistic effect. Thus, the capacity to mobilize fat via LIPL-5 is directly linked to an animal's capacity to withstand long-term nutrient deprivation. Our data establish a role for LIPL-5 and Coelomocytes in regulating fat consumption and lifespan extension upon DR.
Suzanne Grant - One of the best experts on this subject based on the ideXlab platform.
-
generation of monoclonal antibodies to Coelomocytes of the purple sea urchin arbacia punctulata characterization and phenotyping
Developmental and Comparative Immunology, 2007Co-Authors: Suzanne Grant, Gregory BeckAbstract:Cellular cytotoxicity is a key component of animal innate immune responses that is one of the first lines of defense against invaders. There is increasing interest in the study of the cellular immune response, particularly non-specific cytotoxic cells and natural killer cells and their receptors. Studies of non-specific cytotoxic cell and natural killer cell recognition and killing (and the receptors involved) will reveal new and important insights into cellular mechanisms of host defense. Here we describe mAbs specific for Coelomocyte sub-populations of the purple sea urchin, Arbacia punctulata, using highly purified Coelomocyte populations as the antigen source. Monoclonal antibodies were selected using flow cytometric screening methods. Several of the mAbs were shown to bind to two sub-types of Coelomocytes when assayed by fluorescence microscopy. Furthermore, these mAbs inhibited Coelomocyte cytotoxicity against vertebrate target cells in a functional assay. The mAbs have been used in immunoprecipitation studies.