Immunologic and functional evidence for anti–Siglec-9 autoantibodies in intravenous immunoglobulin preparations

Blood ◽  
2006 ◽  
Vol 108 (13) ◽  
pp. 4255-4259 ◽  
Author(s):  
Stephan von Gunten ◽  
Alexander Schaub ◽  
Monique Vogel ◽  
Beda M. Stadler ◽  
Sylvia Miescher ◽  
...  

Abstract Human intravenous immunoglobulin (IVIg) preparations are increasingly used for the treatment of autoimmune diseases. Earlier work demonstrated the presence of autoantibodies against Fas in IVIg, suggesting that IVIg might be able to induce caspase-dependent cell death in Fas-sensitive cells. In this study, we demonstrate that sialic acid–binding Ig-like lectin 9 (Siglec) represents a surface molecule on neutrophils that is activated by IVIg, resulting in caspase-dependent and caspase-independent forms of cell death. Neutrophil death was mediated by naturally occurring anti–Siglec-9 autoantibodies present in IVIg. Moreover, the efficacy of IVIg-mediated neutrophil killing was enhanced by the proinflammatory cytokines granulocyte/macrophage colony-stimulating factor (GM-CSF) and interferon-γ (IFN–γ), and this additional cell death required reactive oxygen species (ROSs) but not caspases. Anti– Siglec-9 autoantibody–depleted IVIg failed to induce this caspase-independent neutrophil death. These findings contribute to our understanding of how IVIg preparations exert their immunoregulatory effects under pathologic conditions and may provide a possible explanation for the neutropenia that is sometimes seen in association with IVIg therapy.

Blood ◽  
1987 ◽  
Vol 69 (6) ◽  
pp. 1782-1785
Author(s):  
DR Branch ◽  
JM Turc ◽  
LJ Guilbert

The murine lymphoblastic cell line DA-1 has been characterized as dependent upon both interleukin-3 (IL-3, multicolony-stimulating factor [multi-CSF]) and granulocyte-macrophage colony-stimulating factor (GM- CSF) for survival and growth. Here we demonstrate that it is responsive to a third hematopoietic factor, the erythroid-specific hormone, erythropoietin (Epo). DA-1 cells are stimulated to proliferate by partly purified natural murine and human Epo, and pure recombinant human Epo. Antibody to Epo specifically blocks Epo-stimulated growth. Maximal growth stimulated by Epo and GM-CSF is similar, and considerably less than that stimulated by multi-CSF. Proliferation stimulated by Epo and GM-CSF is transient, decreasing within 24 to 48 hours of exposure. However, Epo acts cooperatively with GM-CSF to sustain proliferation. With or without GM-CSF, no obvious erythroid differentiation of DA-1 cells occurs after exposure to Epo for up to 72 hours. This is the first report of a growth factor-dependent cell line also responsive to Epo for survival and growth. The availability of this cell line model should greatly facilitate biochemical analysis of the mechanism of Epo growth-stimulating action.


Blood ◽  
1998 ◽  
Vol 91 (9) ◽  
pp. 3347-3356 ◽  
Author(s):  
James L. Slack ◽  
Min Yu

Two major isoforms of PML-RARα are associated with (15;17)-positive acute promyelocytic leukemia (APL); however, functional differences between these isoforms have been difficult to define, and the molecular mechanism by which each isoform contributes to the pathogenesis of APL is not fully understood. To address these issues, the ‘short’ (S) and ‘long’ (L) isoforms of PML-RARα were constitutively expressed in the factor-dependent human erythroleukemia cell line, TF1. Expression of the L, but not the S, isoform inhibited growth of these cells in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF). In the absence of GM-CSF, the S isoform partially protected against apoptosis, while the L isoform accelerated cell death. Treatment with all-trans retinoic acid (ATRA) inhibited cell growth and caused apoptosis only in PML-RARα–expressing cells, and these effects of ATRA were more marked in cells expressing the L isoform. ATRA treatment also led to downregulation of bcl-2 and endogenous RARα in PML-RARα–expressing cells, but had little effect on the level of exogenously expressed PML-RARα. We conclude that (1) subtle differences exist in the biologic activities of the L and S isoforms of PML-RARα, and (2) both isoforms are capable of transducing an ATRA-mediated signal that leads to downregulation of bcl-2 and induction of programmed cell death.


Blood ◽  
1992 ◽  
Vol 80 (11) ◽  
pp. 2883-2890 ◽  
Author(s):  
K Bhalla ◽  
C Tang ◽  
AM Ibrado ◽  
S Grant ◽  
E Tourkina ◽  
...  

Abstract High dose Ara-C (HIDAC) induces programmed cell death (PCD) or apoptosis in vitro in human myeloid leukemia cells, which correlates with the inhibition of their clonogenic survival. Hematopoietic growth factors (HGFs) granulocyte-macrophage colony-stimulating factor (GM- CSF) and interleukin-3 (IL-3) have been demonstrated to enhance the metabolism and cytotoxic effects of HIDAC against leukemic progenitor cells. We examined the effect of pIXY 321 (a GM-CSF/IL-3 fusion protein) on HIDAC-induced PCD and related gene expressions as well as HIDAC-mediated colony growth inhibition of human myeloid leukemia cells. Unlike the previously described effects of HGFs on normal bone marrow progenitor cells, exposure to pIXY 321 alone for up to 24 hours did not suppress PCD in HL-60 or KG-1 cells. However, exposure to pIXY 321 for 20 hours followed by a combined treatment with Ara-C plus pIXY 321 for 4 or 24 hours versus treatment with Ara-C alone significantly enhanced the oligonucleosomal DNA fragmentation characteristic of PCD. This was temporally associated with a marked induction of c-jun expression and a significant decrease in BCL-2. In addition, the treatment with pIXY 321 plus HIDAC versus HIDAC alone produced a significantly greater inhibition of HL-60 colony growth. These findings highlight an additional mechanism of HIDAC-induced leukemic cell death that is augmented by cotreatment with pIXY 321 and may contribute toward an improved antileukemic activity of HIDAC.


Blood ◽  
1987 ◽  
Vol 69 (6) ◽  
pp. 1782-1785 ◽  
Author(s):  
DR Branch ◽  
JM Turc ◽  
LJ Guilbert

Abstract The murine lymphoblastic cell line DA-1 has been characterized as dependent upon both interleukin-3 (IL-3, multicolony-stimulating factor [multi-CSF]) and granulocyte-macrophage colony-stimulating factor (GM- CSF) for survival and growth. Here we demonstrate that it is responsive to a third hematopoietic factor, the erythroid-specific hormone, erythropoietin (Epo). DA-1 cells are stimulated to proliferate by partly purified natural murine and human Epo, and pure recombinant human Epo. Antibody to Epo specifically blocks Epo-stimulated growth. Maximal growth stimulated by Epo and GM-CSF is similar, and considerably less than that stimulated by multi-CSF. Proliferation stimulated by Epo and GM-CSF is transient, decreasing within 24 to 48 hours of exposure. However, Epo acts cooperatively with GM-CSF to sustain proliferation. With or without GM-CSF, no obvious erythroid differentiation of DA-1 cells occurs after exposure to Epo for up to 72 hours. This is the first report of a growth factor-dependent cell line also responsive to Epo for survival and growth. The availability of this cell line model should greatly facilitate biochemical analysis of the mechanism of Epo growth-stimulating action.


Blood ◽  
2003 ◽  
Vol 101 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Yves Delneste ◽  
Peggy Charbonnier ◽  
Nathalie Herbault ◽  
Giovanni Magistrelli ◽  
Gersende Caron ◽  
...  

Abstract Human monocytes differentiate into dendritic cells (DCs) or macrophages according to the nature of environmental signals. Monocytes stimulated with granulocyte-macrophage colony-stimulating factor (GM-CSF) plus interleukin 4 (IL-4) yield DCs. We tested here whether interferon-γ (IFN-γ), a potent activator of macrophages, may modulate monocyte differentiation. Addition of IFN-γ to IL-4 plus GM-CSF–stimulated monocytes switches their differentiation from DCs to CD14−CD64+ macrophages. IFN-γ increases macrophage colony-stimulating factor (M-CSF) and IL-6 production by IL-4 plus GM-CSF–stimulated monocytes by acting at the transcriptional level and acts together with IL-4 to up-regulate M-CSF but not IL-6 production. IFN-γ also increases M-CSF receptor internalization. Results from neutralizing experiments show that both M-CSF and IL-6 are involved in the ability of IFN-γ to skew monocyte differentiation from DCs to macrophages. Finally, this effect of IFN-γ is limited to early stages of differentiation. When added to immature DCs, IFN-γ up-regulates IL-6 but not M-CSF production and does not convert them to macrophages, even in the presence of exogenous M-CSF. In conclusion, IFN-γ shifts monocyte differentiation to macrophages rather than DCs through autocrine M-CSF and IL-6 production. These data show that IFN-γ controls the differentiation of antigen-presenting cells and thereby reveals a new mechanism by which IFN-γ orchestrates the outcome of specific immune responses.


Blood ◽  
2000 ◽  
Vol 96 (4) ◽  
pp. 1230-1238 ◽  
Author(s):  
Tan Jinquan ◽  
Sha Quan ◽  
Henrik H. Jacobi ◽  
Chen Jing ◽  
Anders Millner ◽  
...  

Abstract CXC chemokine receptor 3 (CXCR3), which is known to be expressed predominately on memory and activated T lymphocytes, is a receptor for both interferon γ (IFN-γ)–inducible protein 10 (γIP-10) and monokine induced by IFN-γ (Mig). We report the novel finding that CXCR3 is also expressed on CD34+ hematopoietic progenitors from human cord blood stimulated with granulocyte-macrophage colony-stimulating factor (GM-CSF) but not on freshly isolated CD34+ progenitors. Freshly isolated CD34+progenitors expressed low levels of CXCR3 messenger RNA, but this expression was highly up-regulated by GM-CSF, as indicated by a real-time quantitative reverse transcriptase–polymerase chain reaction technique. γIP-10 and Mig induced chemotaxis of GM-CSF–stimulated CD34+ progenitors by means of CXCR3, since an anti-CXCR3 monoclonal antibody (mAb) was found to block γIP-10–induced and Mig-induced CD34+ progenitor chemotaxis. These chemotactic attracted CD34+ progenitors are colony-forming units—granulocyte-macrophage. γIP-10 and Mig also induced GM-CSF–stimulated CD34+ progenitor adhesion and aggregation by means of CXCR3, a finding confirmed by the observation that anti-CXCR3 mAb blocked these functions of γIP-10 and Mig but not of chemokine stromal cell–derived factor 1α. γIP-10–induced and Mig-induced up-regulation of integrins (CD49a and CD49b) was found to play a crucial role in adhesion of GM-CSF–stimulated CD34+progenitors. Moreover, γIP-10 and Mig stimulated CXCR3 redistribution and cellular polarization in GM-CSF–stimulated CD34+progenitors. These results indicate that CXCR3–γIP-10 and CXCR3–Mig receptor-ligand pairs, as well as the effects of GM-CSF on them, may be especially important in the cytokine/chemokine environment for the physiologic and pathophysiologic events of differentiation of CD34+ hematopoietic progenitors into lymphoid and myeloid stem cells, subsequently immune and inflammatory cells. These processes include transmigration, relocation, differentiation, and maturation of CD34+ hematopoietic progenitors.


Blood ◽  
2010 ◽  
Vol 115 (24) ◽  
pp. 5037-5040 ◽  
Author(s):  
Cristina Ghirelli ◽  
Raphaël Zollinger ◽  
Vassili Soumelis

Abstract Human plasmacytoid predendritic cells (pDCs) can be activated during microbial infection through Toll-like receptor engagement. They are also involved in nonmicrobial inflammatory diseases, but their activation pathways in this context remain elusive. To identify Toll-like receptor-independent pDC activators, we performed a systematic analysis of cytokine receptors on primary human pDCs. Six receptors were expressed both at mRNA and protein levels: interleukin-3 receptor (IL-3R), IL-6R, IL-10R, IL-18R, interferon-γ receptor, and granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor. Only GM-CSF and IL-3 were able to efficiently promote pDC survival and induce their differentiation into dendritic cells. Allogeneic naive CD4 T cells primed with GM-CSF–activated pDCs produced more interferon-γ and less IL-4 and IL-10 compared with IL-3–activated pDCs, indicating a shift in the Th1/Th2 balance. Our data point at a novel function of GM-CSF, which may serve as a link between a pathologic inflammatory environment, pDC activation, and the modulation of CD4 T-cell responses.


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