Talks by dominique bourel
Papers by dominique bourel
Lab Invest, 2003
Intravenous immunoglobulins (IVIg) are therapeutic preparations of normal human polyclonal Ig G (... more Intravenous immunoglobulins (IVIg) are therapeutic preparations of normal human polyclonal Ig G (IgG) that exert immunomodulatory effects in patients with autoimmune or systemic inflammatory diseases. Two different IgG subfractions were evaluated for their respective immunomodulatory effects in the treatment of experimental autoimmune diseases: a fraction enriched in antibodies that recognize the F(ab') 2 portion of IVIg and a fraction of natural polyreactive autoantibodies purified on a dinitrophenyl (DNP)-Affiprep immunoadsorbent. A very small fraction of IgG interacting with DNP but not with F(ab') 2 fragments expressed an increased ability to bind to self-antigens. The anti-DNP fraction, but not the anti-idiotype fraction, protected against inflammation observed in collagen-induced arthritis and experimental autoimmune encephalomyelitis in rats. Furthermore, it was able to reduce the occurrence of spontaneous diabetes mellitus in nonobese diabetic mice at lower concentrations than unfractionated IVIg. The therapeutic benefit of the anti-DNP fraction was associated with the inhibition of secretion of proinflammatory cytokines and stimulation of secretion of IL-1 receptor antagonist. Our results provide evidence that polyreactive autoantibodies play a role in the protective effect of IVIg in experimental models of autoimmune diseases in which inflammatory reactions are part of the disease process.
Journal of Leukocyte Biology, Aug 21, 2008
NK cells can kill antibody-coated target cells following engagement of Fc␥RIIIA, the major activa... more NK cells can kill antibody-coated target cells following engagement of Fc␥RIIIA, the major activating Fc␥R expressed by these cells. The presence of Fc␥RIIC (CD32C) has also been reported, but its contribution to the Fc␥R-dependent effector functions of NK cells remains debated. We demonstrate here that inhibitory Fc␥RIIB is also expressed by a small subset of CD56 ؉ /NKp46 ؉ NK cells and can efficiently down-modulate their Fc␥R-dependent effector function. Immunofluorescence analyses of NK cells from 52 healthy donors showed the presence of CD56 bright /Fc␥RII -(5.2%؎3.4), CD56 dim /Fc␥RII lo/-(94.1%؎3.4), and CD56 dim /Fc␥RII bright (0.64%؎0.72) cells.
J Leukocyte Biol, 2008
NK cells can kill antibody-coated target cells following engagement of Fc␥RIIIA, the major activa... more NK cells can kill antibody-coated target cells following engagement of Fc␥RIIIA, the major activating Fc␥R expressed by these cells. The presence of Fc␥RIIC (CD32C) has also been reported, but its contribution to the Fc␥R-dependent effector functions of NK cells remains debated. We demonstrate here that inhibitory Fc␥RIIB is also expressed by a small subset of CD56 ؉ /NKp46 ؉ NK cells and can efficiently down-modulate their Fc␥R-dependent effector function. Immunofluorescence analyses of NK cells from 52 healthy donors showed the presence of CD56 bright /Fc␥RII -(5.2%؎3.4), CD56 dim /Fc␥RII lo/-(94.1%؎3.4), and CD56 dim /Fc␥RII bright (0.64%؎0.72) cells.
Journal of Immunological Methods, Apr 22, 1999
In vivo biotinylation of antibody fragments with a gene fusion approach is a realistic alternativ... more In vivo biotinylation of antibody fragments with a gene fusion approach is a realistic alternative to conventional in vitro chemical labelling. We have previously reported the construction of a vector system suitable for the bacterial expression of Ž . the binding fragment of antibody Fab genetically linked to the C-terminal domain of Escherichia Coli biotin carboxy Ž U . carrier protein BCCP . A minor fraction of the expressed hybrids was biotinylated in vivo and therefore able to interact with streptavidin. We now show that the large majority of bacterially-expressed Fab-BCCP U fusions are labelled with biotin Ž . when plasmid-encoded biotin holoenzyme synthetase BirA is co-expressed. The yield of biotinylated Fab is maximal when overexpression of BirA is driven by a second compatible plasmid. We took advantage of this property to develop a novel filter assay for the rapid identification of recombinant Fab reacting with immunoglobulin. Starting with total RNA of two newly established murine hybridoma cell lines producing anti-human IgG1 antibodies, we selected in a single experiment the bacterial clones that expressed in vivo biotinylated anti-IgG1 Fab. Sequence analysis of the isolated Fabs showed that they did not derive from a single B clone. In addition, we found that these recombinant Fabs labelled with biotin in vivo are useful for the specific detection of human IgG1 by a solid-phase immunoassay. q 1999 Elsevier Science B.V. All rights reserved.
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Talks by dominique bourel
Papers by dominique bourel