Non-neutralizing antibodies protect from chronic LCMV infection independently of activating FcγR or complement

2013 ◽  
Vol 43 (9) ◽  
pp. 2349-2360 ◽  
Author(s):  
Kirsten Richter ◽  
Annette Oxenius
Keyword(s):  
Neutralizing Antibodies ◽  
Lcmv Infection

scholarly journals Non‐neutralizing antibodies protect against chronic LCMV infection by promoting infection of inflammatory monocytes in mice

2021 ◽  
Author(s):  
Diana Stoycheva ◽  
Ioana Sandu ◽  
Fabienne Gräbnitz ◽  
Ana Amorim ◽  
Mariana Borsa ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Inflammatory Monocytes ◽  
Lcmv Infection

scholarly journals Enhanced Virus Clearance by Early Inducible Lymphocytic Choriomeningitis Virus-Neutralizing Antibodies in Immunoglobulin-Transgenic Mice

1998 ◽  
Vol 72 (3) ◽  
pp. 2253-2258 ◽  
Author(s):  
Peter Seiler ◽  
Ulrich Kalinke ◽  
Thomas Rülicke ◽  
Etienne M. Bucher ◽  
Christian Böse ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Antibody Response ◽  
Acute Phase ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Immunoglobulin M ◽  
Neutralizing Monoclonal Antibody ◽  
Lcmv Infection

ABSTRACT Following infection of mice with lymphocytic choriomeningitis virus (LCMV), virus-neutralizing antibodies appear late, after 30 to 60 days. Such neutralizing antibodies play an important role in protection against reinfection. To analyze whether a neutralizing antibody response which developed earlier could contribute to LCMV clearance during the acute phase of infection, we generated transgenic mice expressing LCMV-neutralizing antibodies. Transgenic mice expressing the immunoglobulin μ heavy chain of the LCMV-neutralizing monoclonal antibody KL25 (H25 transgenic mice) mounted LCMV-neutralizing immunoglobulin M (IgM) serum titers within 8 days after infection. This early inducible LCMV-neutralizing antibody response significantly improved the host’s capacity to clear the infection and did not cause an enhancement of disease after intracerebral (i.c.) LCMV infection. In contrast, mice which had been passively administered LCMV-neutralizing antibodies and transgenic mice exhibiting spontaneous LCMV-neutralizing IgM serum titers (HL25 transgenic mice expressing the immunoglobulin μ heavy and the κ light chain) showed an enhancement of disease after i.c. LCMV infection. Thus, early-inducible LCMV-neutralizing antibodies can contribute to viral clearance in the acute phase of the infection and do not cause antibody-dependent enhancement of disease.

Endothelial Cell Protein S Synthesis Is Upregulated by the Complex of IL-6 and Soluble IL-6 Receptor

1997 ◽  
Vol 77 (05) ◽  
pp. 1014-1019 ◽  
Author(s):  
W Craig Hooper ◽  
Donald J Phillips ◽  
Bruce L Evatt
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Line ◽  
Neutralizing Antibodies ◽  
Hepatoma Cell ◽  
Protein S ◽  
Oncostatin M ◽  
Cell Protein ◽  
Microvascular Endothelial Cell ◽  
Hepatoma Cell Line

SummaryWe have recently demonstrated that the proinflammatory cytokine, interleukin-6 (IL-6), could upregulate the production of protein S in the human hepatoma cell line, HepG-2, but not in endothelial cells. In this study, we have demonstrated that the combination of exogenous IL-6 and soluble IL-6 receptor (sIL-6R) could significantly upregulate protein S production in both primary human umbilical vein endothelial cells (HUVEC) and in the immortalized human microvascular endothelial cell line, HMEC-1. The IL-6/sIL-6R complex was also able to rapidly induce tyrosine phosphorylation of the IL-6 transducer, gpl30. Neutralizing antibodies directed against either IL-6 or gpl30 blocked protein S upregulation by the IL-6/sIL-6R complex. It was also observed that exogenous sIL-6R could also upregulate protein S by forming a complex with IL-6 constitutively produced by the endothelial cell. Two other cytokines which also utilize the gpl30 receptor, oncostatin M (OSM) and leukemia inhibitory factor (LIF), were also able to upregulate endothelial cell protein S. This study demonstrates a mechanism that allows endothelial cells to respond to IL-6 and also illustrates the potential importance of circulating soluble receptors in the regulation of the anticoagulation pathway.

Chapter 2b: The molecular antigenic structure of the TBEV

2020 ◽  
Keyword(s):  
Conformational Changes ◽  
Neutralizing Antibodies ◽  
Lipid Membrane ◽  
Cell Entry ◽  
Antigenic Structure ◽  
E Proteins ◽  
Amino Acid Sequence Level ◽  
Endosomal Membrane ◽  
E Protein ◽  
Golgi Network

TBEV-particles are assembled in an immature, noninfectious form in the endoplasmic reticulum by the envelopment of the viral core (containing the viral RNA) by a lipid membrane associated with two viral proteins, prM and E. Immature particles are transported through the cellular exocytic pathway and conformational changes induced by acidic pH in the trans-Golgi network allow the proteolytic cleavage of prM by furin, a cellular protease, resulting in the release of mature and infectious TBE-virions. The E protein controls cell entry by mediating attachment to as yet ill-defined receptors as well as by low-pH-triggered fusion of the viral and endosomal membrane after uptake by receptor-mediated endocytosis. Because of its key functions in cell entry, the E protein is the primary target of virus neutralizing antibodies, which inhibit these functions by different mechanisms. Although all flavivirus E proteins have a similar overall structure, divergence at the amino acid sequence level is up to 60 percent (e.g. between TBE and dengue viruses), and therefore cross-neutralization as well as (some degree of) cross-protection are limited to relatively closely related flaviviruses, such as those constituting the tick-borne encephalitis serocomplex.

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