Rodent models of complement activation-related pseudoallergy: Inducers, symptoms, inhibitors and reaction mechanisms

Complement activation-related pseudoallergy (CARPA) is a hypersensitivity reaction to intravenous administration of nanoparticle-containing medicines (nanomedicines). This review focuses on CARPA in rodent models: rats, mice, guinea pigs and rabbits. Information on all aspects of hypersensitivity reactions caused by known complement activators (zymosan, cobra venom factor) and different nanomedicines (liposomes, other drug carrier nanocarriers) in these species has been compiled and analyzed, trying to highlight the similarities and differences. What is most common in all species' reactions to i.v. complement activators, liposomes and other nanoparticles is a dose-dependent hemodynamic and cardiopulmonary disturbance manifested in acute, reversible rise or fall of blood pressure and respiratory distress that can lead to shock. Other symptoms include heart rate changes, leukopenia followed by leukocytosis, thrombocytopenia, hemoconcentration due to fluid extravasation (rise of hematocrit) and rise of plasma thromboxane B2. The results of a recent rat study are detailed, which show that rats are 2-3 orders of magnitude less sensitive to liposome-induced CARPA than pigs or hypersensitive humans. It is concluded that CARPA can be studied in rodent models, but they do not necessarily mimic the human reactions in terms of symptom spectrum and sensitivity. © 2015 by De Gruyter

Cardiopulmonary and hemodynamic changes in complement activation-related pseudoallergy

Complement activation-related pseudoallergy (CARPA) is a frequent side effect of intravenous therapies with nanoparticle-containing drugs and biologicals that are recognized by the immune system as foreign. It is an acute infusion reaction dominated by cutaneous and hemodynamic changes, most significantly a cardiopulmonary distress involving major pulmonary hypertension, systemic hypotension and arrhythmias. Because CARPA is unpredictable by conventional allergy tests and it may be life threatening, it can represent a major barrier to the safe therapeutic application of many modern medicines, including liposomal drugs and monoclonal antibodies. This review summarizes and updates the facts and opens questions regarding this phenomenon, with particular focus on its porcine model

Plasma Proteome Profiling with Monoclonal Antibody Libraries: a Pilot Biomarker Analysis for Nanomedicine-Induced Complement Activation

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A juxtaglomeruláris apparátus parakrin szabélyozása: Funkcionális és morfológiai összefüggések normál és kóros körülmények között = Paracrine Control of the Juxtaglomerular Apparatus: Functional and Morphological Correlations in Health and Disease

Speciális technika kifejlesztésével és a két foton lézermikroszkóp segítségével elsőként tettük láthatóvá in vivo a patkány vese afferens arteriola disztális szakaszán található endotheliális fenesztrációt. Kimértük a fenesztrált terület nagyságát és bizonyítottuk annak életkortól, illetve a szervezet aktuális állapotától függő változását. Real time formában nyomon követtük a renin granulumok ezen keresztüli keringésbe jutását. Igazoltuk, hogy a filtráció már a glomerulust megelőző disztális afferens arteriola szakaszban megkezdődik. Vizualizáltuk a juxtaglomeruláris apparátus intersticiális folyadék mozgását és kimutattuk, hogy a juxtaglomeruláris apparátusba folyadék filtrálódik az afferens arteriolából, a mesangiumon keresztül a glomerulusból, illetve a glomerulusból a macula densan keresztül a disztális tubulusba. Ezek az eredmények alapvetően megkérdőjelezik a juxtaglomeruláris apparátus működésére és jelentőségére vonatkozó eddigi elképzeléseinket. A fenesztráció kialakulását, illetve a hozzátartozó nanocsatornák morfológiáját atomerőmikroszkópiával analizáltuk sejttenyészetben. Az angiotenzin II és a vaszkuláris endotheliális növekedési faktor (VEGF) fokozta a fenesztrumok képződését az AT1, illetve a VEGFR-2 receptoron keresztül. E folyamat függ a p38 aktiválódásától. A fenesztráció fokozódása együtt járt a 40kD-os dextran áteresztőképesség növekedésével és a sejtréteg elektromos impedancia csökkenésével. | With a special technical development and the use of two photon laser microscopy, for the first time, in vivo, we managed to visualize the endothelial fenestration at the distal section of the afferent arteriole in rat kidney. The area of the fenestrated section was measured and its change depending on age and actual condition was demonstrated. The passage of the renin granules into the circulation via these fenestrations were followed in real time. We documented that filtration already starts at the distal part of the afferent arteriole before glomerulus. The interstitial fluid movement in the juxtaglomerular apparatus was visualized. It was also shown that in JGA, fluid is filtered via afferent arteriole, mesangium, glomerulus and macula densa into the distal tubule. These findings basically question our understanding about the function and importance of JGA. The development of fenestration and the morphology of the related nanochannels were analyzed in the cell culture with the help of AFM. Angiotensin II and Vascular Endothelial Growth Factor (VEGF) increased fenestrates via AT1 and VEGFR-2 receptors. This process is p38 dependent. Increase in fenestration was accompanied by increase in permeability to 40kD dextran and decrease in cell layer electrical impedance

HIGH DIMENSIONAL CHARACTERISATION OF CELLULAR FEATURES BY SINGLE CELL MASS CYTOMETRY

High resolution measurement characterizing the large number of cellular features is in the focus of recent cell biological research. To achieve these goals single cell mass cytometry combines advantages of the single cell resolution of traditional fluorescence-based flow cytometry with the multiplexicity of inductively coupled plasma-mass spectrometry. Instead of fluorophores detection for mass cytometry is based on stable heavy-metal isotope labeled antibodies. Thus, the autofluorescence and spectral overlapping are eliminated. The current state-of-the-art mass cytometer is capable of measuring up to 135 different stable isotopes of rare earth metals, although the current availability of these tags in high purity limits the usage to around 45 different rare earth metal tags. This unique feature enables researchers to multiplex up to 45 different antibodies in one single tube. Extensive mapping of signaling networks in single cells, cell surface receptor quantification has been also achieved by single cell mass cytometry. Sample multiplexing is also possible by barcoding prior the antibody labeling which enables the combination of 20 different samples in one single tube. Cell types, cellular populations of interest can be visualized on dot plots and the protein expression levels are demonstrated by histograms. Furthermore, gating hierarchy above 10-12 level is also manageable. Mass cytometry deeply reveals cellular heterogeneity on the basis of highly multiplex phenotypical and functional characterization. There are several novel algorithmic approaches to process large datasets such as: SPADE, viSNE, Citrus. The monitoring of the complex immunophenotype is highly relevant in several human diseases which have been previously restricted to limited number of markers with flow cytometry compared to single cell mass cytometry. Human systemic autoimmune diseases (rheumatoid arthritis, systemic lupus erythemathosus and systemic sclerosis) are under investigation. The cellular complexity and functional heterogeneity of solid tumors, inflammatory diseases and animal models (tumor, bone marrow, spleen, lymph nodes) will be also analyzed in our laboratory by single cell mass spectrometry. Funding: GINOP-2.3.2-15-2016-00030 (LGP); János Bolyai Research Scholarship (GJSz, BO/00139/17/8

Contribution of CARPA to polystyrene NP effects in pigs

Background: It has been proposed that many hypersensitivity reactions to nanopharmaceuticals represent complement (C)-activation-related pseudoallergy (CARPA), and that pigs provide a sensitive animal model to study the phenomenon. However, a recent study suggested that pulmonary hypertension, the pivotal symptom of porcine CARPA, is not mediated by C in cases of polystyrene nanoparticle (PS-NP)-induced reactions. Goals: To characterize PS-NPs and reexamine the contribution of CARPA to their pulmonary reactivity in pigs. Study design: C activation by 200, 500, and 750 nm (diameter) PS-NPs and their opsonization were measured in human and pig sera, respectively, and correlated with hemodynamic effects of the same NPs in pigs in vivo. Methods: Physicochemical characterization of PS-NPs included size, ζ-potential, cryo-transmission electron microscopy, and hydrophobicity analyses. C activation in human serum was measured by ELISA and opsonization of PS-NPs in pig serum by Western blot and flow cytometry. Pulmonary vasoactivity of PS-NPs was quantified in the porcine CARPA model. Results: PS-NPs are monodisperse, highly hydrophobic spheres with strong negative surface charge. In human serum, they caused size-dependent, significant rises in C3a, Bb, and sC5b-9, but not C4d. Exposure to pig serum led within minutes to deposition of C5b-9 and opsonic iC3b on the NPs, and opsonic iC3b fragments (C3dg, C3d) also appeared in serum. PS-NPs caused major hemodynamic changes in pigs, primarily pulmonary hypertension, on the same time scale (minutes) as iC3b fragmentation and opsonization proceeded. There was significant correlation between C activation by different PS-NPs in human serum and pulmonary hypertension in pigs. Conclusion: PS-NPs have extreme surface properties with no relevance to clinically used nanomedicines. They can activate C via the alternative pathway, entailing instantaneous opsonization of NPs in pig serum. Therefore, rather than being solely C-independent reactivity, the mechanism of PS-NP-induced hypersensitivity in pigs may involve C activation. These data are consistent with the “double-hit” concept of nanoparticle-induced hypersensitivity reactions involving both CARPA and C-independent pseudoallergy

Pulmonary intravascular macrophages: Prime suspects as cellular mediators of porcine CARPA

Pigs provide a highly sensitive and quantitative in vivo model for complement (C) activation-related pseudoallergy (CARPA), a hypersensitivity reaction caused by some state-of-art nanomedicines. In an effort to understand the mechanism of the pigs' unique sensitivity for CARPA, this review focuses on pulmonary intravascular macrophages (PIMs), which are abundantly present in the lung of pigs. These cells represent a macrophage subpopulation whose unique qualities explain the characteristic symptoms of CARPA in this species, most importantly the rapidly (within minutes) developing pulmonary vasoconstriction, leading to elevation of pulmonary arterial pressure. The unique qualities of PIM cells include the following; 1) they are strongly adhered to the capillary walls via desmosome-like intercellular adhesion plaques, which secure stable and lasting direct exposition of the bulk of these cells to the blood stream; 2) their ruffled surface engaged in intense phagocytic activity ensures efficient binding and phagocytosis of nanoparticles; 3) PIM cells express anaphylatoxin receptors, this way C activation can trigger these cells, 4) they also express pattern recognition molecules on their surface, whose engagement with certain coated nanoparticles may also activate these cells or act in synergy with anaphylatoxins and, finally 5) their high metabolic activity and capability for immediate secretion of vasoactive mediators upon stimulation explain the circulatory blockage and other robust physiological effects that their stimulation may cause. These qualities taken together with reports on liposome uptake by PIM cells during CARPA and the possible presence of these cells in human lung suggests that PIM cells may be a potential therapeutic target against CARPA. © 2015 by De Gruyter