Detection of Soluble CR3 (CD11b/CD18) by Time-Resolved Immunofluorometry

Nielsen, Gitte Krogh; Vorup-Jensen, Thomas

doi:10.1007/978-1-62703-724-2_30

Cited by 6 publications

(6 citation statements)

References 33 publications

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“…The measurement of sCD18 concentration in mouse serum was carried out with a TRIFMA as described previously [ 18 ]. Briefly, microtiter plates were coated with a rat anti-mouse CD18 IgG2a capture antibody (clone 313903) at a concentration of 1 μg/ml in PBS pH 7.4 at 4°C overnight.…”

Section: Methodsmentioning

confidence: 99%

“…β2 integrin small molecule antagonists are under evaluation for the treatment of other autoimmune diseases. [ 11 ] We and others have demonstrated a soluble form of CD18 (sCD18) resulting from sheddase activity [ 12 – 18 ]. Shedding of CD18 is increased during chemotaxis and following stimulation with TNFα [ 12 , 16 , 17 ], and the sCD18 complexes compete with the cell-expressed CD18 integrins for binding to ICAM-1 [ 12 , 19 ].…”

Section: Introductionmentioning

confidence: 99%

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Changes in Soluble CD18 in Murine Autoimmune Arthritis and Rheumatoid Arthritis Reflect Disease Establishment and Treatment Response

et al. 2016

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IntroductionIn rheumatoid arthritis (RA) immune activation and presence of autoantibodies may precede clinical onset of disease, and joint destruction can progress despite remission. However, the underlying temporal changes of such immune system abnormalities in the inflammatory response during treat-to-target strategies remain poorly understood. We have previously reported low levels of the soluble form of CD18 (sCD18) in plasma from patients with chronic RA and spondyloarthritis. Here, we study the changes of sCD18 before and during treatment of early RA and following arthritis induction in murine models of rheumatoid arthritis.MethodsThe level of sCD18 was analyzed with a time-resolved immunoflourometric assay in 1) plasma from early treatment naïve RA patients during a treat-to-target strategy (the OPERA cohort), 2) plasma from chronic RA patients, 3) serum from SKG and CIA mice following arthritis induction, and 4) supernatants from synovial fluid mononuclear cells (SFMCs) and peripheral blood mononuclear cells (PBMCs) from 6 RA patients cultured with TNFα or adalimumab.ResultsPlasma levels of sCD18 were decreased in chronic RA patients compared with early RA patients and in early RA patients compared with healthy controls. After 12 months of treatment the levels in early RA patients were similar to healthy controls. This normalization of plasma sCD18 levels was more pronounced in patients with very early disease who achieved an early ACR response. Plasma sCD18 levels were associated with radiographic progression. Correspondingly, the serum level of sCD18 was decreased in SKG mice 6 weeks after arthritis induction compared with healthy littermates. The sCD18 levels in both SKG and CIA mice exhibited a biphasic course after arthritis induction with an initial increase above baseline followed by a decline. Shedding of CD18 from RA SFMC and RA PBMC cultures was increased by TNFα and decreased by adalimumab.ConclusionsThe plasma sCD18 levels were altered in patients with RA, in mice with autoimmune arthritis and in cell cultures treated with TNFα and adalimumab. Decreased levels of plasma sCD18 could reflect autoimmunity in transition from early to chronic disease and normalization in response to treatment could reflect autoimmunity in remission.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Changes in Soluble CD18 in Murine Autoimmune Arthritis and Rheumatoid Arthritis Reflect Disease Establishment and Treatment Response

et al. 2016

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“…This finding is remarkable, as attempts to quantify the amount of Mac‐1 in human plasma has been limited by the only low, albeit detectable, CD11b signals developed in our assays . By contrast, soluble Mac‐1 is detected readily in murine serum . The observations made in the present study now point to sCD18 complexes capable of modulating Mac‐1 binding to complement.…”

Section: Discussionmentioning

confidence: 50%

Altered levels of soluble CD18 may associate immune mechanisms with outcome in sepsis

Kragstrup

Juul-Madsen

Christiansen

et al. 2017

Clinical and Experimental Immunology

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The pathogenesis of sepsis involves a dual inflammatory response, with a hyperinflammatory phase followed by, or in combination with, a hypoinflammatory phase. The adhesion molecules lymphocyte function-associated antigen (LFA-1) (CD11a/CD18) and macrophage-1 (Mac-1) (CD11b/CD18) support leucocyte adhesion to intercellular adhesion molecules and phagocytosis through complement opsonization, both processes relevant to the immune response during sepsis. Here, we investigate the role of soluble (s)CD18 in sepsis with emphasis on sCD18 as a mechanistic biomarker of immune reactions and outcome of sepsis. sCD18 levels were measured in 15 septic and 15 critically ill non-septic patients. Fifteen healthy volunteers served as controls. CD18 shedding from human mononuclear cells was increased in vitro by several proinflammatory mediators relevant in sepsis. sCD18 inhibited cell adhesion to the complement fragment iC3b, which is a ligand for CD11b/CD18, also known as Mac-1 or complement receptor 3. Serum sCD18 levels in sepsis non-survivors displayed two distinct peaks permitting a partitioning into two groups, namely sCD18 'high' and sCD18 'low', with median levels of sCD18 at 2158 mU/ml [interquartile range (IQR) 2093-2811 mU/ml] and 488 mU/ml (IQR 360-617 mU/ml), respectively, at the day of intensive care unit admission. Serum sCD18 levels partitioned sepsis non-survivors into one group of 'high' sCD18 and low CRP and another group with 'low' sCD18 and high C-reactive protein. Together with the mechanistic data generated in vitro, we suggest the partitioning in sCD18 to reflect a compensatory anti-inflammatory response syndrome and hyperinflammation, respectively, manifested as part of sepsis.

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“…In house TRIFMA assays where utilized to measure sCD18 in human plasma and mouse plasma as previously published 21 . In- house ELISA assays were utilized to measure sCD163 in human plasma as previously described 22 .…”

Section: Methodsmentioning

confidence: 99%

Decreased monocyte shedding of the migration inhibitor soluble CD18 in alcoholic hepatitis

Støy

Sandahl

Hansen

et al. 2018

Clinical and Translational Gastroenterology

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ObjectivesDuring alcoholic hepatitis (AH) monocytes traverse the vascular boundaries and massively invade the liver. In principle, tissue extravasation can be limited through shedding of CD18 integrins from leukocytes, including monocytes. The soluble (s) product sCD18 conceals adhesion receptors on the endothelium, which reduces monocyte extravasation. In AH, monocytes are dysfunctional, but whether this involves their self-generated anti-migration is unknown. Our aim was, therefore, to investigate monocyte CD18 dynamics in AH.MethodsWe studied 50 AH patients and 20 healthy controls. We measured monocyte expression and conformational activation of CD18, plasma (P)-sCD18, stimulated in vitro CD18 shedding and P-sCD18 in a short-term chronic-binge mouse model.ResultsAH-derived monocytes had a 30–60% higher expression of active CD18 receptors (p < 0.01), but the sCD18 concentration per monocyte was reduced in vivo by 30% and in vitro by 120% (p < 0.01). Ethanol reduced the in vitro shedding of CD18 in the patients only. TNFα increased sCD18 concentration per monocyte, but less so in the patients (p < 0.04). P-sCD18 per monocyte was inversely related to disease severity. In early alcoholic liver disease, P-sCD18 was decreased in the mouse model.ConclusionsThe monocyte CD18 integrins are highly activated in AH and the single monocyte shedding of CD18 was decreased favoring tissue extravasation. Alcohol in itself and altered monocyte responsiveness to TNFα may explain this lowered shedding.Translational impactThe contribution of this mechanism to the excessive monocyte liver infiltration in AH should be further explored as it may serve as a potential therapeutic target to limit liver inflammation.

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Detection of Soluble CR3 (CD11b/CD18) by Time-Resolved Immunofluorometry

Cited by 6 publications

References 33 publications

Changes in Soluble CD18 in Murine Autoimmune Arthritis and Rheumatoid Arthritis Reflect Disease Establishment and Treatment Response

Changes in Soluble CD18 in Murine Autoimmune Arthritis and Rheumatoid Arthritis Reflect Disease Establishment and Treatment Response

Altered levels of soluble CD18 may associate immune mechanisms with outcome in sepsis

Decreased monocyte shedding of the migration inhibitor soluble CD18 in alcoholic hepatitis

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