1.
Nilsson Ekdahl, Kristina, et al.
(författare)
A human whole-blood model to study the activation of innate immunity system triggered by nanoparticles as a demonstrator for toxicity
2019
Ingår i: Science and Technology of Advanced Materials. - : Taylor & Francis Group. - 1468-6996 .- 1878-5514. ; 20:1, s. 688-698
Forskningsöversikt (refereegranskat) abstract
In this review article, we focus on activation of the soluble components of the innate immune system triggered by nonbiological compounds and stress variances in activation due to the difference in size between nanoparticles (NPs) and larger particles or bulk material of the same chemical and physical composition. We then discuss the impact of the so-called protein corona which is formed on the surface of NPs when they come in contact with blood or other body fluids. For example, NPs which bind inert proteins, proteins which are prone to activate the contact system (e.g., factor XII), which may lead to clotting and fibrin formation or the complement system (e.g., IgG or C3), which may result in inflammation and vascular damage. Furthermore, we describe a whole blood model which we have developed to monitor activation and interaction between different components of innate immunity: blood protein cascade systems, platelets, leukocytes, cytokine generation, which are induced by NPs. Finally, we describe our own studies on innate immunity system activation induced by three fundamentally different species of NPs (two types of engineered NPs and diesel NPs) as demonstrator of the utility of an initial determination of the composition of the protein corona formed on NPs exposed to ethylenediaminetetraacetic acid (EDTA) plasma and subsequent analysis in our whole blood model. [GRAPHICS] .
2.
Halbgebauer, Rebecca, et al.
(författare)
Thirty-Eight-Negative Kinase 1 Is a Mediator of Acute Kidney Injury in Experimental and Clinical Traumatic Hemorrhagic Shock
2020
Ingår i: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 11, s. 1-12
Tidskriftsartikel (refereegranskat) abstract
Trauma represents a major socioeconomic burden worldwide. After a severe injury, hemorrhagic shock (HS) as a frequent concomitant aspect is a central driver of systemic inflammation and organ damage. The kidney is often strongly affected by traumatic-HS, and acute kidney injury (AKI) poses the patient at great risk for adverse outcome. Recently, thirty-eight-negative kinase 1 (TNK1) was proposed to play a detrimental role in organ damage after trauma/HS. Therefore, we aimed to assess the role of TNK1 in HS-induced kidney injury in a murine and apost hocanalysis of a non-human primate model of HS comparable to the clinical situation. Mice and non-human primates underwent resuscitated HS at 30 mmHg for 60 min. 5 h after the induction of shock, animals were assessed for systemic inflammation and TNK1 expression in the kidney.In vitro, murine distal convoluted tubule cells were stimulated with inflammatory mediators to gain mechanistic insights into the role of TNK1 in kidney dysfunction. In a translational approach, we investigated blood drawn from either healthy volunteers or severely injured patients at different time points after trauma (from arrival at the emergency room and at fixed time intervals until 10 days post injury; identifier: NCT02682550,). A pronounced inflammatory response, as seen by increased IL-6 plasma levels as well as early signs of AKI, were observed in mice, non-human primates, and humans after trauma/HS. TNK1 was found in the plasma early after trauma-HS in trauma patients. Renal TNK1 expression was significantly increased in mice and non-human primates after HS, and these effects with concomitant induction of apoptosis were blocked by therapeutic inhibition of complement C3 activation in non-human primates. Mechanistically,in vitrodata suggested that IL-6 rather than C3 cleavage products induced upregulation of TNK1 and impaired barrier function in renal epithelial cells. In conclusion, these data indicate that C3 inhibitionin vivomay inhibit an excessive inflammatory response and mediator release, thereby indirectly neutralizing TNK1 as a potent driver of organ damage. In future studies, we will address the therapeutic potential of direct TNK1 inhibition in the context of severe tissue trauma with different degrees of additional HS.
3.
Ekdahl, Kristina N., et al.
(författare)
Complement inhibition in biomaterial- and biosurface-induced thromboinflammation
2016
Ingår i: Seminars in Immunology. - : Elsevier BV. - 1044-5323 .- 1096-3618. ; 28:3, s. 268-277
Tidskriftsartikel (refereegranskat) abstract
Therapeutic medicine today includes a vast number of procedures involving the use of biomaterials, transplantation of therapeutic cells or cell clusters, as well as of solid organs. These treatment modalities are obviously of great benefit to the patient, but also present a great challenge to the innate immune system, since they involve direct exposure of non-biological materials, cells of non-hematological origin as well as endothelial cells, damaged by ischemia-perfusion in solid organs to proteins and cells in the blood. The result of such an exposure may be an inappropriate activation of the complement and contact/kallikrein systems, which produce mediators capable of triggering the platelets and PMNs and monocytes, which can ultimately result in thrombotic and inflammatory (i.e., a thrombo-inflammatory) response to the treatment modality. In this concept review, we give an overview of the mechanisms of recognition within the innate immunity system, with the aim to identify suitable points for intervention. Finally, we discuss emerging and promising techniques for surface modification of biomaterials and cells with specific inhibitors in order to diminish thromboinflammation and improve clinical outcome.
4.
Nilsson Ekdahl, Kristina, et al.
(författare)
Contact (kallikrein/kinin) system activation in whole human blood induced by low concentrations of α-Fe2O3 nanoparticles
2018
Ingår i: Nanomedicine. - : Elsevier. - 1549-9634 .- 1549-9642. ; 14:3, s. 735-744
Tidskriftsartikel (refereegranskat) abstract
Iron-oxide nanoparticles (NPs) generated by environmental events are likely to represent health problems. α-Fe2O3 NPs were synthesized, characterized and tested in a model for toxicity utilizing human whole blood without added anticoagulant. MALDI-TOF of the corona was performed and activation markers for plasma cascade systems (complement, contact and coagulation systems), platelet consumption and release of growth factors, MPO, and chemokine/cytokines from blood cells were analyzed. The coronas formed on the pristine α-Fe2O3 NPs contained contact system proteins and they induced massive activation of the contact (kinin/kallikrein) system, as well as thrombin generation, platelet activation, and release of two pro-angiogeneic growth factors: platelet-derived growth factor and vascular endothelial growth factor, whereas complement activation was unaffected. The α-Fe2O3 NPs exhibited a noticeable toxicity, with kinin/kallikreinactivation, which may be associated with hypotension and long-term angiogenesis in vivo, with implications for cancer, arteriosclerosis and pulmonary disease.
5.
Babiker, Adil A., et al.
(författare)
Prostasome Involvement in the Development and Growth of Prostate Cancer
2010
Ingår i: The Open Prostate Cancer Journal. - : Bentham Science Publishers Ltd.. - 1876-8229. ; 3, s. 1-13
Forskningsöversikt (refereegranskat) abstract
Prostasomes are extracellularly occurring submicron, membrane-surrounded organelles produced by the epithelial cells of the prostate and present in semen after secretion. Even dedifferentiated prostate cancer cells have preserved their ability to produce and export prostasomes to the extracellular space. The precise physiological role of prostasomes is not known, although some of their properties assign them to important physiological and patho-physiological functions that could be exploited in prostate cancer growth and development. In this review, some new properties of seminal and malignant cell line (DU145, PC-3 and LNCaP) prostasomes will be discussed. There are typical differences in the expressions and activities of prostasomal CD59, ATPase, protein kinases and tissue factor (TF) as well as in the transfer of prostasomal CD59 to CD59-deficient erythrocytes (rabbit and human PNH erythrocytes). CD59, protein kinases and TF exhibit characteristic patterns of overexpression by malignant cell prostasomes. A high ATPase activity is recognized on seminal prostasomes with minimal activity on malignant cell prostasomes resulting in more residual ATP available for phosphorylation reactions. Several proteins are phosphorylated by prostasomal protein kinases, namely, complement component C3, fibrinogen, vitronectin and E-cadherin. Furthermore, TF is identified as the main endogenous phosphorylation substrate on prostasomes. In addition, prothrombotic effects of prostasomes are demonstrated. DU145 and PC-3 cell-derived prostasomes exert a higher clotting effect on whole blood and plasma compared to LNCaP cell-derived and seminal prostasomes. In conclusion, malignant cell prostasomes show an increased ability to interact with the biological system in favor of prostate cancer cell promotion and survival. The roles played by prostasomes in this context may improve the understanding of the mechanisms that help the prostate cancer cells to avoid the complement attack (CD59 transfer and phosphorylation and inactivation of C3), to promote angiogenesis (TF) and to metastasize. It may also provide a better understanding of some of the complications usually seen in some terminal prostate cancer patients like thrombotic events and tendency to develop disseminated intravascular coagulation.
6.
Biglarnia, Ali Reza, et al.
(författare)
The multifaceted role of complement in kidney transplantation
2018
Ingår i: Nature Reviews Nephrology. - : Nature Publishing Group. - 1759-5061 .- 1759-507X. ; 14:12, s. 767-781
Forskningsöversikt (refereegranskat) abstract
Increasing evidence indicates an integral role for the complement system in the deleterious inflammatory reactions that occur during critical phases of the transplantation process, such as brain or cardiac death of the donor, surgical trauma, organ preservation and ischaemia-reperfusion injury, as well as in humoral and cellular immune responses to the allograft. Ischaemia is the most common cause of complement activation in kidney transplantation and in combination with reperfusion is a major cause of inflammation and graft damage. Complement also has a prominent role in antibody-mediated rejection (ABMR) owing to ABO and HL A incompatibility, which leads to devastating damage to the transplanted kidney. Emerging drugs and treatment modalities that inhibit complement activation at various stages in the complement cascade are being developed to ameliorate the damage caused by complement activation in transplantation. These promising new therapies have various potential applications at different stages in the process of transplantation, including inhibiting the destructive effects of ischaemia and/or reperfusion injury, treating ABMR, inducing accommodation and modulating the adaptive immune response.
7.
Sandholm, Kerstin, et al.
(författare)
Evaluation of a Novel Immunoassay for Quantification of C1q for Clinical Diagnostic Use
2019
Ingår i: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 10
Tidskriftsartikel (refereegranskat) abstract
Objectives: C1q is a valuable biomarker of disease activity in systemic lupus erythematosus (SLE). The "gold standard" assay, rocket immunoelectrophoresis (RIE), is time-consuming, and thus a shift to soluble immune precipitation techniques such as nephelometry has occurred. However, quantification of C1q with these techniques has been questioned as a result of the antibody binding properties of C1q. In the present work, we have compared results using various techniques (RIE, nephelometry, and ELISA) and have developed and validated a new magnetic bead-based sandwich immunoassay (MBSI). Methods: C1q was quantified by nephelometry and the new sandwich immunoassay in 45 serum samples analyzed using RIE. C1q was also assessed in plasma using RIE and sandwich immunoassay in samples from SLE patients with nephritis (n = 69), SLE patients without nephritis (n = 310) as classified by BILAG score, and matched controls (n = 322). In addition, cerebrospinal fluid (CSF) samples from 31 patients, previously analyzed with ELISA, were also analyzed with the MBSI to test the behavior of this new assay in the lower detection range. Results: We found a strong correlation between the new MBSI, RIE, and ELISA, but not with nephelometry. The MBSI demonstrated lower levels of C1q in SLE patients than in matched controls (p < 0.0001), and patients with nephritis had lower levels than patients without nephritis (p < 0.01). Similarily, RIE showed significant differences between the patient groups (p < 0.0001). An association was also found between the levels of C1q and the SLE disease activity index (SLEDAI). Furthermore, there was good correlation between the values obtained by MBSI and ELISA, in both serum (r = 0.960) and CSF (r = 0.786), underscoring the ability of both techniques to measure low concentrations of C1q with high accuracy. Conclusion: The sandwich immunoassay correlated well with RIE, but soluble immune precipitation techniques, such as nephelometry, did not appear suitable alternatives, since C1q itself, and possibly anti-C1q antibodies, interfered with the measurements. The new sandwich immunoassay is therefore a good replacement for RIE in monitoring SLE disease activity.
8.
Babiker, Adil A., et al.
(författare)
Mapping pro- and antiangiogenic factors on the surface of prostasomes of normal and malignant cell origin
2010
Ingår i: The Prostate. - : Wiley. - 0270-4137 .- 1097-0045. ; 70:8, s. 834-847
Tidskriftsartikel (refereegranskat) abstract
BACKGROUND: Angiogenesis is the formation of new blood vessels by capillary sprouting from pre-existing vessels. Tumor growth is angiogenesis-dependent and the formation of new blood vessels is associated with the increased expression of angiogenic factors. Prostasomes are secretory granules produced, stored and released by the glandular epithelial cells of the prostate. We investigated the expression of selected angiogenic and anti-angiogenic factors on the surface of prostasomes of different origins as well as the direct effect of prostasomes on angiogenesis. METHODS: VEGF, endothelin-1, endostatin, and thrombospondin-1 were determined on prostasomes from seminal fluid and human prostate cancer cell lines (DU145,PC-3,LNCaP) using different immunochemical techniques. Human dermal microvascular endothelial cells were incubated with seminal and DU145 cell-prostasomes and with radioactive thymidine. The effect of prostasomes on angiogenesis was judged by measuring the uptake of labeled thymidine. The presence of any deleterious effects of prostasomes on the endothelial cells was investigated using thymidine assay and confocal laser microscopy. RESULTS: VEGF and endothelin-1 were determined on malignant cell-prostasomes (no difference between cell lines) but not determined on seminal prostasomes. The same applies for the expression of endostatin but with much higher expression on malignant cell-prostasomes with obvious differences between them. Seminal and DU145 cell-prostasomes were found to have anti-angiogenic effect which was more expressed by DU145 cell-prostasomes. No deleterious effect of prostasomes on endothelial function was detected using either thymidine assay or microscopy. CONCLUSIONS: Prostasomes contain pro- and anti-angiogenic factors that function to counteract each other unless the impact from one side exceeds the other to bring about dysequilibrium.
9.
Bäck, Jennie, et al.
(författare)
Activated human platelets induce factor XIIa-mediated contact activation
2010
Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 391:1, s. 11-17
Tidskriftsartikel (refereegranskat) abstract
Earlier studies have shown that isolated platelets in buffer systems can promote activation of FXII or amplify contact activation, in the presence of a negatively charge substance or material. Still proof is lacking that FXII is activated by platelets in a more physiological environment. In this study we investigate if activated platelets can induce FXII-mediated contact activation and whether this activation affects clot formation in human blood. Human platelets were activated with a thrombin receptor-activating peptide, SFLLRN-amide, in platelet-rich plasma or in whole blood. FXIIa and FXIa in complex with preferentially antithrombin (AT) and to some extent C1-inhibitor (C1INH) were generated in response to TRAP stimulation. This contact activation was independent of surface-mediated contact activation, tissue factor pathway or thrombin. In clotting whole blood FXIIa-AT and FXIa-AT complexes were specifically formed, demonstrating that AT is a potent inhibitor of FXIIa and FXIa generated by platelet activation. Contact activation proteins were analyzed by flow cytometry and FXII, FXI, high-molecular weight kininogen, and prekallikrein were detected on activated platelets. Using chromogenic assays, enzymatic activity of platelet-associated FXIIa, FXIa, and kallikrein were demonstrated. Inhibition of FXIIa in non-anticoagulated blood also prolonged the clotting time. We conclude that platelet activation triggers FXII-mediated contact activation on the surface and in the vicinity of activated platelets. This leads specifically to generation of FXIIa-AT and FXIa-AT complexes, and contributes to clot formation. Activated platelets may thereby constitute an intravascular locus for contact activation, which may explain the recently reported importance of FXII in thrombus formation.
10.
Gustafson, Elisabet, et al.
(författare)
Control of IBMIR Induced by Fresh and Cryopreserved Hepatocytes by Low Molecular Weight Dextran Sulfate Versus Heparin
2017
Ingår i: Cell Transplantation. - : Sage Publications. - 0963-6897 .- 1555-3892. ; 26:1, s. 71-81
Tidskriftsartikel (refereegranskat) abstract
Rapid destruction of hepatocytes after hepatocyte transplantation has hampered the application of this procedure clinically. The instant blood-mediated inflammatory reaction (IBMIR) is a plausible underlying cause for this cell loss. The present study was designed to evaluate the capacity of low molecular weight dextran sulfate (LMW-DS) to control these initial reactions from the innate immune system. Fresh and cryopreserved hepatocytes were tested in an in vitro whole-blood model using ABO-compatible blood. The ability to elicit IBMIR and the capacity of LMW-DS (100 mu g/ml) to attenuate the degree of activation of the cascade systems were monitored. The effect was also compared to conventional anticoagulant therapy using unfractionated heparin (1 IU/ml). Both fresh and freeze thawed hepatocytes elicited IBMIR to the same extent. LMW-DS reduced the platelet loss and maintained the cell counts at the same degree as unfractionated heparin, but controlled the coagulation and complement systems significantly more efficiently than heparin. LMW-DS also attenuated the IBMIR elicited by freeze thawed cells. Therefore, LMW-DS inhibits the cascade systems and maintains the cell counts in blood triggered by both fresh and cryopreserved hepatocytes in direct contact with ABO-matched blood. LMW-DS at a previously used and clinically applicable concentration (100 mu g/ml) inhibits IBMIR in vitro and is therefore a potential IBMIR inhibitor in hepatocyte transplantation.
