gamma-Fe2O3 nanoparticles obtained by coprecipitation of Fe(II) and Fe(III) chlorides with a base and subsequent oxidation were coated with a shell of hydrophilic biocompatible poly(N,N-dimethylacrylamide) (PDMAAm). Various initiators were attached to the iron oxide surface to enable the use of the "grafting-from" approach for immobilization of PDMAAm. They included 2,2'-azobis(2-methylpropanimidamide) dihydrochloride (AMPA), 2,2'-azobis(N-hydroxy-2-methylpropanimidamide) dihydrochloride (ABHA) and 4-cyano-4-{[1-cyano-3-(N-hydroxycarbamoyl)-1-methylpropyl]azo}pentanoic acid (CCHPA). Engulfment of PDMAAm-coated y-Fe2O3 nanoparticles by murine J774.2 macrophages was investigated. Only some nanoparticles were engulfed by the macrophages. PDMAAm-AMPA-gamma-Fe2O3 and PDMAAm-ABHA-y-Fe2O3 nanoparticles were rapidly engulfed by the cells. In contrast, neat y-Fe2O3 and PDMAAm-CCHPA-gamma-Fe2O3 particles induced formation of transparent vacuoles indicating toxicity of the particles. Thus, PDMAAm-coated AMPA- and ABHA-gamma-Fe2O3 nanoparticles can be recommended as non-toxic labels for mammalian cells.

• MeSH
• akrylamidy chemie   farmakologie   MeSH
• buněčné linie MeSH
• fluorescenční mikroskopie MeSH
• hydrofobní a hydrofilní interakce účinky léků   MeSH
• magnetické jevy MeSH
• magnety * MeSH
• makrofágy cytologie   účinky léků   metabolismus   MeSH
• myši MeSH
• nanočástice chemie   ultrastruktura   MeSH
• polymerizace účinky léků   MeSH
• radiační rozptyl MeSH
• savci metabolismus   MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• světlo MeSH
• velikost částic MeSH
• železité sloučeniny farmakologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• akrylamidy MeSH
• ferric oxide MeSH Prohlížeč
• poly(N,N-dimethylacrylamide) MeSH Prohlížeč
• železité sloučeniny MeSH

INTRODUCTION: Red blood cells (RBCs), also known as erythrocytes, are underestimated in their role in the immune system. In mammals, erythrocytes undergo maturation that involves the loss of nuclei, resulting in limited transcription and protein synthesis capabilities. However, the nucleated nature of non-mammalian RBCs is challenging this conventional understanding of RBCs. Notably, in bony fishes, research indicates that RBCs are not only susceptible to pathogen attacks but express immune receptors and effector molecules. However, given the abundance of RBCs and their interaction with every physiological system, we postulate that they act in surveillance as sentinels, rapid responders, and messengers. METHODS: We performed a series of in vitro experiments with Cyprinus carpio RBCs exposed to Aeromonas hydrophila, as well as in vivo laboratory infections using different concentrations of bacteria. RESULTS: qPCR revealed that RBCs express genes of several inflammatory cytokines. Using cyprinid-specific antibodies, we confirmed that RBCs secreted tumor necrosis factor alpha (TNFα) and interferon gamma (IFNγ). In contrast to these indirect immune mechanisms, we observed that RBCs produce reactive oxygen species and, through transmission electron and confocal microscopy, that RBCs can engulf particles. Finally, RBCs expressed and upregulated several putative toll-like receptors, including tlr4 and tlr9, in response to A. hydrophila infection in vivo. DISCUSSION: Overall, the RBC repertoire of pattern recognition receptors, their secretion of effector molecules, and their swift response make them immune sentinels capable of rapidly detecting and signaling the presence of foreign pathogens. By studying the interaction between a bacterium and erythrocytes, we provide novel insights into how the latter may contribute to overall innate and adaptive immune responses of teleost fishes.

• Klíčová slova
• Aeromonas hydrophila (A. hydrophila), Cyprinus carpio, bacteria, cytokines, engulfment, inflammation, red blood cell (RBC), teleost fish,
• MeSH
• Aeromonas hydrophila * imunologie   MeSH
• cytokiny * metabolismus   imunologie   MeSH
• erytrocyty * imunologie   metabolismus   MeSH
• fagocytóza imunologie   MeSH
• gramnegativní bakteriální infekce * imunologie   MeSH
• kapři * imunologie   mikrobiologie   MeSH
• nemoci ryb * imunologie   mikrobiologie   MeSH
• PAMP struktury imunologie   MeSH
• přirozená imunita MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cytokiny * MeSH
• PAMP struktury MeSH

Apoptosis as a vital process is necessary for human intrauterine development. Not only the induction and course of apoptosis, but engulfment of the apoptotic cells (bodies) were the centre of our interest. Macrophages were detected in the early stages of human intrauterine development and the role of macrophages in the clearance of apoptotic cells in the early stages of human metanephros development was confirmed.

• MeSH
• apoptóza fyziologie   MeSH
• fagocytóza * MeSH
• ledviny embryologie   MeSH
• lidé MeSH
• makrofágy fyziologie   MeSH
• organogeneze * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The effect of the establishment of Entodinium caudatum on the population of Eudiplodinium maggii was examined in the rumen of three sheep fed a hay/ground barley diet. The cell concentration of E. maggii were 15.9-38.5 and 11.7-12.4 x 10(3) cells per g of the rumen contents in the absence and presence of E. caudatum, respectively. Microscopic analysis showed that starch was the only material engulfed by eudiplodinia irrespective of the time after feeding and the presence or absence of E. caudatum. Up to 82-93% of individuals contained starch grains when E. maggii was the only ciliate species in the rumen; the proportion was 70-77% after entodinia had been established. The largest quantity of starch engulfed by E. maggii ciliates was 12.4-19.0 and 6.7-7.6 mg per 100 mg protozoal dry mass in the absence and presence of entodinia, respectively. No visible engulfment of hay was observed in vivo in spite of the fact that hay particles up to 42 microns in length were dominating in rumen fluid. Ingestion of fresh particles of hay separated from the rumen digesta was found when they were added in the proportion of 1 g per 40 mL suspension of ciliates. No preferential intake of starch was observed when E. maggii ciliates were incubated in vitro with a mixture of hay and barley starch. It is suggested that competition for starch between the two ciliate species was responsible for the drop in the numbers of E. maggii. This could result from a too low concentration of small particles of hay in the rumen fluid.

• MeSH
• bachor chemie   parazitologie   MeSH
• ekosystém MeSH
• ovce parazitologie   MeSH
• populační dynamika MeSH
• škrob metabolismus   MeSH
• Trichostomatida chemie   cytologie   růst a vývoj   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• škrob MeSH

Treatment of murine EL4 T cell lymphoma with N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer conjugates of doxorubicin (Dox) leads to complete tumor regression and to the development of therapy-dependent longlasting cancer resistance. This phenomenon occurs with two types of Dox conjugates tested, despite differences in the covalent linkage of Dox to the polymer carrier. Such a cancer resistance cannot fully express in conventional treatment with free Dox, due to substantial immunotoxicity of the treatment, which was not observed in the polymer conjugates. In this study, calreticulin (CRT) translocation and high mobility group box-1 protein (HMGB1) release was observed in EL4 cells treated with a conjugate releasing Dox by a pH-dependent manner. As a result, the treated tumor cells were engulfed by dendritic cells (DC) in vitro, and induced their expression of CD80, CD86, and MHC II maturation markers. Conjugates with Dox bound via an amide bond only increased translocation of HSPs to the membrane, which led to an elevated phagocytosis but was not sufficient to induce increase of the maturation markers on DCs in vitro. Both types of conjugates induced engulfment of the target tumor cells in vivo, that was more intense than that seen with free Dox. It means that the induction of anti-tumor immunity documented upon treatment of EL4 lymphoma with HPMA-bound Dox conjugates does not rely solely on CRT-mediated cell death, but involves multiple mechanisms.

• MeSH
• antigeny CD80 metabolismus   MeSH
• antigeny CD86 metabolismus   MeSH
• apoptóza účinky léků   MeSH
• chemorezistence účinky léků   MeSH
• dendritické buňky cytologie   imunologie   MeSH
• doxorubicin aplikace a dávkování   analogy a deriváty   chemie   toxicita   MeSH
• fagocytóza MeSH
• kalretikulin metabolismus   MeSH
• koncentrace vodíkových iontů MeSH
• kyseliny polymethakrylové aplikace a dávkování   chemie   toxicita   MeSH
• lymfom T-buněčný farmakoterapie   imunologie   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nosiče léků chemie   MeSH
• protein HMGB1 metabolismus   MeSH
• proteiny teplotního šoku metabolismus   MeSH
• protinádorové látky aplikace a dávkování   chemie   toxicita   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny CD80 MeSH
• antigeny CD86 MeSH
• doxorubicin-N-(2-hydroxypropyl)methacrylamide copolymer conjugate MeSH Prohlížeč
• doxorubicin MeSH
• kalretikulin MeSH
• kyseliny polymethakrylové MeSH
• nosiče léků MeSH
• protein HMGB1 MeSH
• proteiny teplotního šoku MeSH
• protinádorové látky MeSH

Among morphological phenomena, cellular patterns in developing sensory epithelia have gained attention in recent years. Although physical models for cellular rearrangements are well-established thanks to a large bulk of experimental work, their computational implementation lacks solid mathematical background and involves experimentally unreachable parameters. Here we introduce a level set-based computational framework as a tool to rigorously investigate evolving cellular patterns, and study its mathematical and computational properties. We illustrate that a compelling feature of the method is its ability to correctly handle complex topology changes, including frequent cell intercalations. Combining this accurate numerical scheme with an established mathematical model, we show that the proposed framework features minimum possible number of parameters and is capable of reproducing a wide range of tissue morphological phenomena, such as cell sorting, engulfment or internalization. In particular, thanks to precise mathematical treatment of cellular intercalations, this method succeeds in simulating experimentally observed development of cellular mosaic patterns in sensory epithelia.

• MeSH
• algoritmy * MeSH
• biologické modely * MeSH
• epitel MeSH
• morfogeneze MeSH
• software MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Sepsis and septic shock remain leading causes of morbidity and mortality for patients in the intensive care unit. During the early phase, immune cells produce various cytokines leading to prompt activation of the immune system. Polymorphonuclear leukocytes (PMNs) respond to different signals producing inflammatory factors and executing their antimicrobial mechanisms, resulting in the engulfment and elimination of invading pathogens. However, excessive activation caused by various inflammatory signals produced during sepsis progression can lead to the alteration of PMN signaling and subsequent defects in their functionality. Here, we analyzed samples from 34 patients in septic shock, focusing on PMNs gene expression and proteome changes associated with septic shock. We revealed that, compared to those patients who survived longer than five days, PMNs from patients who had fulminant sepsis were characterized by a dysfunctional hyper-activation, show altered metabolism, and recent exit from the cell cycle and signs of cellular lifespan. We believe that this multi-omics approach, although limited, pinpoints the alterations in PMNs' functionality, which may be rescued by targeted treatments.

• Klíčová slova
• dysfunctionality, polymorphonuclears, proteomics, sepsis, septic shock, transcriptomics,
• MeSH
• jednotky intenzivní péče MeSH
• kohortové studie MeSH
• lidé středního věku MeSH
• lidé MeSH
• neutrofily imunologie   patologie   MeSH
• prospektivní studie MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• sepse imunologie   patologie   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The platinum(IV) prodrug trans,trans,trans-[Pt(N3)2(OH)2(py)2] (1) is stable and non-toxic in the dark, but potently cytotoxic to cancer cells when irradiated by visible light, including cisplatin-resistant cells. On irradiation with visible light, it generates reactive Pt(II) species which can attack DNA, and produces reactive oxygen species (ROS) and reactive nitrogen species (RNS) which exert unusual effects on biochemical pathways. We now show that its novel mechanism of action includes induction of immunogenic cell death (ICD). Treatment of cancer cells with 1 followed by photoirradiation with visible light induces calreticulin (CRT) expression at the surface of dying cancer cells. This is accompanied by release of high mobility group protein-1B (HMGB1) and the secretion of ATP. Autophagy appears to play a key role in this chemotherapeutically-stimulated ICD. The observed uneven distribution of ecto-CRT promotes phagocytosis, confirmed by the observation of engulfment of photoirradiated CT26 colorectal cancer cells treated with 1 by J774.A1 macrophages. The photoactivatable prodrug 1 has a unique mechanism of action which distinguishes it from other platinum drugs due to its immunomodulating properties, which may enhance its anticancer efficacy.

• Publikační typ
• časopisecké články MeSH

Parasites are widespread and diverse in oceanic plankton and many of them infect single-celled algae for survival. How these parasites develop and scavenge energy within the host and how the cellular organization and metabolism of the host is altered remain open questions. Combining quantitative structural and chemical imaging with time-resolved transcriptomics, we unveil dramatic morphological and metabolic changes of the marine parasite Amoebophrya (Syndiniales) during intracellular infection, particularly following engulfment and digestion of nutrient-rich host chromosomes. Changes include a sequential acristate and cristate mitochondrion with a 200-fold increase in volume, a 13-fold increase in nucleus volume, development of Golgi apparatus and a metabolic switch from glycolysis (within the host) to TCA (free-living dinospore). Similar changes are seen in apicomplexan parasites, thus underlining convergent traits driven by metabolic constraints and the infection cycle. In the algal host, energy-producing organelles (plastid, mitochondria) remain relatively intact during most of the infection. We also observed that sugar reserves diminish while lipid droplets increase. Rapid infection of the host nucleus could be a "zombifying" strategy, allowing the parasite to digest nutrient-rich chromosomes and escape cytoplasmic defense, whilst benefiting from maintained carbon-energy production of the host cell.

• MeSH
• cukry MeSH
• Dinoflagellata * MeSH
• mikrořasy * MeSH
• paraziti * MeSH
• uhlík MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cukry MeSH
• uhlík MeSH

A substantial portion of eukaryote diversity consists of algae with complex plastids, i.e., plastids originating from eukaryote-to-eukaryote endosymbioses. These plastids are characteristic by a deviating number of envelope membranes (higher than two), and sometimes a remnant nucleus of the endosymbiont alga, termed the nucleomorph, is present. Complex plastid-bearing algae are therefore much like living matryoshka dolls, eukaryotes within eukaryotes. In comparison, primary plastids of Archaeplastida (plants, green algae, red algae, and glaucophytes) arose upon a single endosymbiosis event with a cyanobacterium and are surrounded by two membranes. Complex plastids were acquired several times by unrelated groups nested within eukaryotic heterotrophs, suggesting complex plastids are somewhat easier to obtain than primary plastids. This is consistent with the existence of higher-order and serial endosymbioses, i.e., engulfment of complex plastid-bearing algae by (tertiary) eukaryotic hosts and functional plastid replacements, respectively. Plastid endosymbiosis is typical by a massive transfer of genetic material from the endosymbiont to the host nucleus and metabolic rearrangements related to the trophic switch to phototrophy; this is necessary to establish metabolic integration of the plastid and control over its division. Although photosynthesis is the main advantage of plastid acquisition, algae that lost photosynthesis often maintain complex plastids, suggesting their roles beyond photosynthesis. This chapter summarizes basic knowledge on acquisition and functions of complex plastid.

• Klíčová slova
• Complex endosymbiosis, Plastid replacement, Reductive evolution,
• MeSH
• biologická evoluce MeSH
• Eukaryota klasifikace   genetika   metabolismus   MeSH
• fotosyntéza MeSH
• plastidy genetika   metabolismus   MeSH
• symbióza * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH