The Thiol Group Reactivity and the Antioxidant Property of Human Serum Albumin Are Controlled by the Joint Action of Fatty Acids and Glucose Binding.

The binding of ubiquitous serum ligands (free fatty acids) to human serum albumin (HSA) or its glycation can affect thiol group reactivity, thus influencing its antioxidant activity. The effects of stearic acid (SA) and glucose binding on HSA structural changes and thiol group content and reactivity were monitored by fluoroscopy and the Ellman method during a 14-day incubation in molar ratios to HSA that mimic pathophysiological conditions. Upon incubation with 5 mM glucose, HSA glycation was the same as HSA without it, in three different HSA:SA molar ratios (HSA:SA-1:1-2-4). The protective effect of SA on the antioxidant property of HSA under different glucose regimes (5-10-20 mM) was significantly affected by molar ratios of HSA:SA. Thiol reactivity was fully restored with 5-20 mM glucose at a 1:1 HSA:SA ratio, while the highest thiol content recovery was in pathological glucose regimes at a 1:1 HSA:SA ratio. The SA affinity for HSA increased significantly (1.5- and 1.3-fold, p < 0.01) with 5 and 10 mM glucose compared to the control. These results deepen the knowledge about the possible regulation of the antioxidant role of HSA in diabetes and other pathophysiological conditions and enable the design of future HSA-drug studies which, in turn, is important for clinicians when designing information-based treatments.

Multistep Approach Points to Compounds Responsible for the Biological Activity and Safety of Hydrolates from Nine Lamiaceae Medicinal Plants on Human Skin Fibroblasts.

As byproducts of essential oil distillation, hydrolates are used in natural cosmetics/biomedicine due to their beneficial skin effects. However, data on their safety with relevant biological targets, such as human skin cells, are scarce. Therefore, we have tested nine hydrolates from the Lamiaceae family with skin fibroblasts that are responsible for extracellular collagenous matrix builds. Thyme, oregano, and winter savoury hydrolates showed several times higher total phenolics, which correlated strongly with their radical scavenging and antioxidative capacity; there was no correlation between their viability profiles and the reducing sugar levels. No proteins/peptides were detected. All hydrolates appeared safe for prolonged skin exposure except for 10-fold diluted lavender, which showed cytotoxicity (~20%), as well as rosemary and lavandin (~10%) using viability, DNA synthesis, and cell count testing. Clary sage, oregano, lemon balm, and thyme hydrolates (10-fold diluted) increased fibroblast viability and/or proliferation by 10-30% compared with the control, while their viability remained unaffected by Mentha and winter savoury. In line with the STITCH database, increased viability could be attributed to thymol presence in oregano and thyme hydrolates in lemon balm, which is most likely attributable to neral and geranial. The proliferative effect of clary sage could be supported by alpha-terpineol, not linalool. The major volatile organic compounds (VOCs) associated with cytotoxic effects on fibroblasts were borneol, 1,8-cineole, and terpinene-4-ol. Further research with pure compounds is warranted to confirm the roles of VOCs in the observed effects that are relevant to cosmetic and wound healing aspects.

Antioxidant Properties of Protein-Rich Plant Foods in Gastrointestinal Digestion-Peanuts as Our Antioxidant Friend or Foe in Allergies.

Thermally processed peanuts are ideal plant models for studying the relationship between allergenicity and antioxidant capacity of protein-rich foods, besides lipids, carbohydrates and phytochemicals. Peanut is highly praised in the human diet; however, it is rich in allergens (>75% of total proteins). One-third of peanut allergens belong to the products of genes responsible for the defence of plants against stress conditions. The proximate composition of major peanut macromolecules and polyphenols is reviewed, focusing on the identity and relative abundance of all peanut proteins derived from recent proteomic studies. The importance of thermal processing, gastrointestinal digestion (performed by INFOGEST protocol) and their influence on allergenicity and antioxidant properties of protein-rich plant food matrices is elaborated. Antioxidant properties of bioactive peptides from nuts were also considered. Moreover, there are no studies dealing simultaneously with the antioxidant and allergenic properties of protein- and polyphenol-rich foods, considering all the molecules that can significantly contribute to the antioxidant capacity during and after gastrointestinal digestion. In summary, proteins and carbohydrates are underappreciated sources of antioxidant power released during the gastrointestinal digestion of protein-rich plant foods, and it is crucial to decipher their antioxidant contribution in addition to polyphenols and vitamins before and after gastrointestinal digestion.

Sandwich ELISA for the Quantification of Nucleocapsid Protein of SARS-CoV-2 Based on Polyclonal Antibodies from Two Different Species.

In this study, a cost-effective sandwich ELISA test, based on polyclonal antibodies, for routine quantification SARS-CoV-2 nucleocapsid (N) protein was developed. The recombinant N protein was produced and used for the production of mice and rabbit antisera. Polyclonal N protein-specific antibodies served as capture and detection antibodies. The prototype ELISA has LOD 0.93 ng/mL and LOQ 5.3 ng/mL, with a linear range of 1.52-48.83 ng/mL. N protein heat pretreatment (56 °C, 1 h) decreased, while pretreatment with 1% Triton X-100 increased analytical ELISA sensitivity. The diagnostic specificity of ELISA was 100% (95% CI, 91.19-100.00%) and sensitivity was 52.94% (95% CI, 35.13-70.22%) compared to rtRT-PCR (Ct < 40). Profoundly higher sensitivity was obtained using patient samples mostly containing Wuhan-similar variants (Wuhan, alpha, and delta), 62.50% (95% CI, 40.59 to 81.20%), in comparison to samples mostly containing Wuhan-distant variants (Omicron) 30.00% (6.67-65.25%). The developed product has relatively high diagnostic sensitivity in relation to its analytical sensitivity due to the usage of polyclonal antibodies from two species, providing a wide repertoire of antibodies against multiple N protein epitopes. Moreover, the fast, simple, and inexpensive production of polyclonal antibodies, as the most expensive assay components, would result in affordable antigen tests.

Proteomic Profiling of Major Peanut Allergens and Their Post-Translational Modifications Affected by Roasting.

Post-translational modifications (PTMs) are covalent changes occurring on amino acid side chains of proteins and yet are neglected structural and functional aspects of protein architecture. The objective was to detect differences in PTM profiles that take place after roasting using open PTM search. We conducted a bottom-up proteomic study to investigate the impact of peanut roasting on readily soluble allergens and their PTM profiles. Proteomic PTM profiling of certain modifications was confirmed by Western blotting with a series of PTM-specific antibodies. In addition to inducing protein aggregation and denaturation, roasting may facilitate change in their PTM pattern and relative profiling. We have shown that Ara h 1 is the most modified major allergen in both samples in terms of modification versatility and extent. The most frequent PTM was methionine oxidation, especially in roasted samples. PTMs uniquely found in roasted samples were hydroxylation (Trp), formylation (Arg/Lys), and oxidation or hydroxylation (Asn). Raw and roasted peanut extracts did not differ in the binding of IgE from the serum of peanut-sensitised individuals done by ELISA. This study provides a better understanding of how roasting impacts the PTM profile of major peanut allergens and provides a good foundation for further exploration of PTMs.

INFOGEST Digestion Assay of Raw and Roasted Hazelnuts and Its Impact on Allergens and Their IgE Binding Activity.

Most of the food allergens sensitized via the gastrointestinal tract resist thermal treatments and digestion, particularly digestion by pepsin. Roasted hazelnuts are more commonly consumed than raw ones. Since no studies have characterized gastric digestion protein fragments of raw and roasted hazelnuts nor their IgE binding properties, we compared these aspects of raw and roasted hazelnuts' gastric digesta obtained by INFOGEST protocol. Their electrophoretically resolved profiles were probed with hazelnut allergic patients' sera in 1D and 2D immunoblots. Electrophoretic profiles demonstrated pepsin digestion of all hazelnut allergens to varying extents. While 2D immunoblots indicated that roasting slightly reduced allergenicity, IgE ELISA with the pool of sera showed a slight significant (10%) increase in IgE binding in both gastric digesta. Cor a 9 isolated from the raw and roasted hazelnuts, characterized by far and near CD, remained stable after roasting, with preserved IgE reactivity. Its immunoreactivity contribution by inhibitory ELISA was noticeable in raw and roasted hazelnut digesta; its activity was slightly stronger in the roasted preparations. Roasting has a visible impact on proteins; however, it did not affect overall IgE reactivity. Gastric digestion slightly increases the overall IgE reactivity in raw and roasted hazelnuts, and may therefore impact the profiles of allergens and their fragments available to interact with the immune system in the small intestine.

Electronic cigarette liquids impair metabolic cooperation and alter proteomic profiles in V79 cells.

BACKGROUND: Although still considered a safer alternative to classical cigarettes, growing body of work points to harmful effects of electronic cigarettes (e-cigarettes) affecting a range of cellular processes. The biological effect of e-cigarettes needs to be investigated in more detail considering their widespread use. METHODS: In this study, we treated V79 lung fibroblasts with sub-cytotoxic concentration of e-cigarette liquids, with and without nicotine. Mutagenicity was evaluated by HPRT assay, genotoxicity by comet assay and the effect on cellular communication by metabolic cooperation assay. Additionally, comprehensive proteome analysis was performed via high resolution, parallel accumulation serial fragmentation-PASEF mass spectrometry. RESULTS: E-cigarette liquid concentration used in this study showed no mutagenic or genotoxic effect, however it negatively impacted metabolic cooperation between V79 cells. Both e-cigarette liquids induced significant depletion in total number of proteins and impairment of mitochondrial function in treated cells. The focal adhesion proteins were upregulated, which is in accordance with the results of metabolic cooperation assay. Increased presence of posttranslational modifications (PTMs), including carbonylation and direct oxidative modifications, was observed. Data are available via ProteomeXchange with identifier PXD032071. CONCLUSIONS: Our study revealed impairment of metabolic cooperation as well as significant proteome and PTMs alterations in V79 cells treated with e-cigarette liquid warranting future studies on e-cigarettes health impact.

Enterocytes in Food Hypersensitivity Reactions.

Food hypersensitivity reactions are adverse reactions to harmless dietary substances, whose causes are hidden within derangements of the complex immune machinery of humans and mammals. Until recently, enterocytes were considered as solely absorptive cells providing a physical barrier for unwanted lumen constituents. This review focuses on the enterocytes, which are the hub for innate and adaptive immune reactions. Furthermore, the ambiguous nature of enterocytes is also reflected in the fact that enterocytes can be considered as antigen-presenting cells since they constitutively express major histocompatibility complex (MHC) class II molecules. Taken together, it becomes clear that enterocytes have an immense role in maintaining oral tolerance to foreign antigens. In general, the immune system and its mechanisms underlying food hypersensitivity are still unknown and the involvement of components belonging to other anatomical systems, such as enterocytes, in these mechanisms make their elucidation even more difficult. The findings from studies with animal models provide us with valuable information about allergic mechanisms in the animal world, while on the other hand, these models are used to extrapolate results to the pathological conditions occurring in humans. There is a constant need for studies that deal with this topic and can overcome the glitches related to ethics in working with animals.

Expression, purification and immunological characterization of recombinant nucleocapsid protein fragment from SARS-CoV-2.

Serological testing is important method for diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Nucleocapsid (N) protein is the most abundant virus derived protein and strong immunogen. We aimed to find its efficient, low-cost production. SARS-CoV-2 recombinant fragment of nucleocapsid protein (rfNP; 58-419 aa) was expressed in E. coli in soluble form, purified and characterized biochemically and immunologically. Purified rfNP has secondary structure of full-length recombinant N protein, with high percentage of disordered structure (34.2%) and of ß-sheet (40.7%). rfNP was tested in immunoblot using sera of COVID-19 convalescent patients. ELISA was optimized with sera of RT-PCR confirmed positive symptomatic patients and healthy individuals. IgG detection sensitivity was 96% (47/50) and specificity 97% (67/68), while IgM detection was slightly lower (94% and 96.5%, respectively). Cost-effective approach for soluble recombinant N protein fragment production was developed, with reliable IgG and IgM antibodies detection of SARS-CoV-2 infection.

Discrete Hf18 Metal-oxo Cluster as a Heterogeneous Nanozyme for Site-Specific Proteolysis.

The selective hydrolysis of proteins by non-enzymatic catalysis is difficult to achieve, yet it is crucial for applications in biotechnology and proteomics. Herein, we report that discrete hafnium metal-oxo cluster [Hf18 O10 (OH)26 (SO4 )13 ⋅(H2 O)33 ] (Hf18 ), which is centred by the same hexamer motif found in many MOFs, acts as a heterogeneous catalyst for the efficient hydrolysis of horse heart myoglobin (HHM) in low buffer concentrations. Among 154 amino acids present in the sequence of HHM, strictly selective cleavage at only 6 solvent accessible aspartate residues was observed. Mechanistic experiments suggest that the hydrolytic activity is likely derived from the actuation of HfIV Lewis acidic sites and the Brønsted acidic surface of Hf18 . X-ray scattering and ESI-MS revealed that Hf18 is completely insoluble in these conditions, confirming the HHM hydrolysis is caused by a heterogeneous reaction of the solid Hf18 cluster, and not from smaller, soluble Hf species that could leach into solution.

Thermal Processing of Peanut Grains Impairs Their Mimicked Gastrointestinal Digestion While Downstream Defatting Treatments Affect Digestomic Profiles.

Resistance to digestion by digestive proteases represents a critical property of many food allergens. Recently, a harmonized INFOGEST protocol was proposed for solid food digestion. The protocol proposes digestion conditions suitable for all kinds of solid and liquid foods. However, peanuts, as a lipid-rich food, represent a challenge for downstream analyses of the digestome. This is particularly reflected in the methodological difficulties in analyzing proteins and peptides in the presence of lipids. Therefore, the removal of the lipids seems to be a prerequisite for the downstream analysis of digestomes of lipid-rich foods. Here, we aimed to compare the digestomes of raw and thermally treated (boiled and roasted) peanuts, resulting from the INFOGEST digestion protocol for solid food, upon defatting the digests in two different manners. The most reproducible results of peanut digests were obtained in downstream analyses on TCA/acetone defatting. Unfortunately, defatting, even with an optimized TCA/acetone procedure, leads to the loss of proteins and peptides. The results of our study reveal that different thermal treatments of peanuts affect protein extraction and gastric/gastrointestinal digestion. Roasting of peanuts seems to enhance the extraction of proteins during intestinal digestion to a notable extent. The increased intestinal digestion is a consequence of the delayed extraction of thermally treated peanut proteins, which are poorly soluble in acidic gastric digestion juice but are easily extracted when the pH of the media is raised as in the subsequent intestinal phase of the digestion. Thermal processing of peanuts impaired the gastrointestinal digestion of the peanut proteins, especially in the case of roasted samples.

In-depth quantitative profiling of post-translational modifications of Timothy grass pollen allergome in relation to environmental oxidative stress.

An association between pollution (e.g., from traffic emissions) and the increased prevalence of respiratory allergies has been observed. Field-realistic exposure studies provide the most relevant assessment of the effects of the intensity and diversity of urban and industrial contamination on pollen structure and allergenicity. The significance of in-depth post-translational modification (PTM) studies of pollen proteomes, when compared with studies on other aspects of pollution and altered pollen allergenicity, has not yet been determined; hence, little progress has been made within this field. We undertook a comprehensive comparative analysis of multiple polluted and environmentally preserved Phleum pratense (Timothy grass) pollen samples using scanning electron microscopy, in-depth PTM profiling, determination of organic and inorganic pollutants, analysis of the release of sub-pollen particles and phenols/proteins, and analysis of proteome expression using high resolution tandem mass spectrometry. In addition, we used quantitative enzyme-linked immunosorbent assays (ELISA) and immunoglobulin E (IgE) immunoblotting. An increased phenolic content and release of sub-pollen particles was found in pollen samples from the polluted area, including a significantly higher content of mercury, cadmium, and manganese, with irregular long spines on pollen grain surface structures. Antioxidative defense-related enzymes were significantly upregulated and seven oxidative PTMs were significantly increased (methionine, histidine, lysine, and proline oxidation; tyrosine glycosylation, lysine 4-hydroxy-2-nonenal adduct, and lysine carbamylation) in pollen exposed to the chemical plant and road traffic pollution sources. Oxidative modifications affected several Timothy pollen allergens; Phl p 6, in particular, exhibited several different oxidative modifications. The expression of Phl p 6, 12, and 13 allergens were downregulated in polluted pollen, and IgE binding to pollen extract was substantially lower in the 18 patients studied, as measured by quantitative ELISA. Quantitative, unrestricted, and detailed PTM searches using an enrichment-free approach pointed to modification of Timothy pollen allergens and suggested that heavy metals are primarily responsible for oxidative stress effects observed in pollen proteins.

Evaluation of Food Allergy in Children by Skin Prick Tests with Commercial Extracts and Fresh Foods, Specific IgE and, Open Oral Food Challenge-Our Five Years Experience in Food Allergy Work-up.

IgE- mediated food allergy affects 6-8% of children. Our study aimed to define the correlations between the results obtained with skin prick tests (SPTs) using commercial extracts and fresh foods, and the correlations between these result and those obtained with specific IgE (sIgE) and/ or challenge. Children aged from 2 months to 6 years were recruited prospectively. Overall 571 children were positive to one food. In all children we performed  SPT using commercial extracts of suspected food and fresh foods and sIgE. If SPT and sIgE test results did not correspond to the history, we performed open oral food challenge. Sensitivity of SPT with commercial extracts for all tested food was poor (3-35%), while  sensitivity of fresh food skin prick tests (FFSPT) was excellent (50-100%), and showed correlation with open oral food challenge (p<0.001). Our results suggest that fresh food extracts are more effective in detecting sensitization and with levels of sIgE greater than class 3 could predict clinical reactivity, without the need for potentially hazardous food challenges.

Lysine acetylation of major Chlamydia trachomatis antigens.

Chlamydia trachomatis (Ct) is a human pathogen causing trachoma and infertility. We investigated acetylation at lysine residues of chlamydial antigenic proteins: major outer membrane protein (MOMP), 60 kDa chaperonin (chlamydial Hsp60), elongation factor G (EF-G), enolase and the polymorphic membrane proteins PmpB, PmpE and PmpF. 60 kDa chaperonin, EF-G and PmpB showed the highest degree of acetylation. Our data show that important Ct antigens could be post-translationally modified by acetylation of lysine residues at multiple sites. Further studies are needed to investigate total acetylome of Ct and the impact PTMs might have on Ct biology and pathogenicity.

Composition of polyphenol and polyamide compounds in common ragweed (Ambrosia artemisiifolia L.) pollen and sub-pollen particles.

Phenolic composition of Ambrosia artemisiifolia L. pollen and sub-pollen particles (SPP) aqueous extracts was determined, using a novel extraction procedure. Total phenolic and flavonoid content was determined, as well as the antioxidative properties of the extract. Main components of water-soluble pollen phenolics are monoglycosides and malonyl-mono- and diglycosides of isorhamnetin, quercetin and kaempferol, while spermidine derivatives were identified as the dominant polyamides. SPP are similar in composition to pollen phenolics (predominant isorhamnetin and quercetin monoglycosides), but lacking small phenolic molecules (<450Da). Ethanol-based extraction protocol revealed one-third lower amount of total phenolics in SPP than in pollen. For the first time in any pollen species, SPP and pollen phenolic compositions were compared in detail, with an UHPLC/ESI-LTQ-Orbitrap-MS-MS approach, revealing the presence of spermidine derivatives in both SPP and pollen, not previously reported in Ambrosia species.

Thrombin stimulates VSMC proliferation through an EGFR-dependent pathway: involvement of MMP-2.

In this study, the role of epidermal growth factor receptor (EGFR), extracellular signal-regulated kinase (ERK1/2), heparin-binding EGF-like growth factor (HB-EGF), general metalloproteinases, matrix metalloproteinases-2 (MMP-2) in mediating the mitogenic action of thrombin in rat vascular smooth muscle cells (VSMC) was investigated. The incubation of rat VSMC with thrombin (1 U/ml) for 5 min resulted in significant (p < 0.001) increase of ERK1/2 phosphorylation by 8.7 ± 0.9-fold, EGFR phosphorylation by 8.5 ± 1.3-fold (p < 0.001) and DNA synthesis by 3.6 ± 0.4-fold (p < 0.001). Separate 30-min pretreatments with EGFR tyrosine kinase irreversible inhibitor, 10 µM PD169540 (PD), and 20 µM anti-HB-EGF antibody significantly reduced thrombin-stimulated EGFR and ERK1/2 phosphorylation by 81, 72 % and by 48 and 61 %, respectively. Furthermore, the same pretreatments with PD or anti-HB-EGF antibody reduced thrombin-induced VSMC proliferation by 44 and 45 %, respectively. In addition, 30-min pretreatments with 10 µM specific MMP-2 inhibitor significantly reduced thrombin-stimulated phosphorylation of both EGFR and ERK1/2 by 25 %. Moreover, the same pretreatment with MMP-2 inhibitor reduced thrombin-induced VSMC proliferation by 45 %. These results show that the thrombin-induced DNA synthesis correlates with the level of ERK1/2 activation rather than EGFR activation. These results further suggest that thrombin acts through EGFR and ERK 1/2 signaling pathways involving MMP-2 to upregulate proliferation of VSMC.

Immunoproteomic characterization of Ambrosia artemisiifolia pollen allergens in canine atopic dermatitis.

Canine atopic dermatitis (CAD) is an immune system disorder that affects 10-15% of the canine population. Short ragweed (Ambrosia artemisiifolia) pollen represents one of the major seasonal sources of allergenic pollen proteins in Europe, particularly in the Pannonian valley of the Balkan region. In Serbia, about 66% of atopic dogs showed a positive intradermal skin test with its pollen extract, which is second to house dust mites. Therefore, characterization of Ambrosia artemisiifolia pollen components, in terms of defining major and minor allergens that induce clinically manifested allergic reaction in dogs, is important for valid diagnosis and efficient therapy. This study has, for the first time, characterized and identified major Ambrosia artemisiifolia allergens in CAD, using an immunoproteomic approach. To assess the prevalence of specific IgE in electrophoretically separated ragweed pollen proteins, individual reactivity of sera from dogs with CAD was analyzed and compared to the reactivity of sera from healthy dogs in the non-reducing conditions, which were found optimal for specific canine IgE detection. A specific IgE band (38 kDa) was recognized as the most dominant allergen in CAD, occurring in 81% of positive dog's sera. 2-D immunoblotting followed by a mass spectrometry peptide fingerprint analyses with pooled canine and human atopic sera, revealed that 38 kDa major Ambrosia atremisiifolia allergens in CAD were all five isoallergens of the Amb a 1 group (antigen E), including the previously named Amb a 2 (antigen K). In contrast to canine sera, human atopic sera also recognized lower mass allergens such as the ß fragment of Amb a 1 and profilins (Amb a 8 variants). The most prominent ragweed proteins in CAD, represent, as in humans, variants of all five isoallergens of the Amb a 1 group (pectate lyase): Amb a 1.0101 and its natural variant E1XUL2, Amb a 1.0202, 1.0304, 1.0402 and the natural variant of Amb a 1.0501, E1XUM0, as well as the α fragment of pollen allergen Amb a 1.0201.

Human cytomegalovirus infection and atherothrombosis.

Vascular endothelium, as a key regulator of hemostasis, mediates vascular dilatation, prevents platelet adhesion, and inhibits thrombin generation. Endothelial dysfunction caused by acute or chronic inflammation, such as in atherosclerosis, creates a proinflammatory environment which supports leukocyte transmigration toward inflammatory sites, and at the same time promotes coagulation, thrombin generation, and fibrin deposition in an attempt to close the wound. Life-long persistent infection with human cytomegalovirus (HCMV) has been associated with atherosclerosis. In vivo studies have revealed that HCMV infection of the vessel wall affects various cells including monocytes/macrophages, smooth muscle cells (SMCs) and endothelial cells (ECs). HCMV-infected SMCs within vascular lesions display enhanced proliferation and impaired apoptosis, which contribute to intima-media thickening, plaque formation and restenosis. Monocytes play a central role in the process of viral dissemination, whereas ECs may represent a viral reservoir, maintaining persistent infection in HCMV-infected atherosclerotic patients following the primary infection. Persistent infection leads to dysfunction of ECs and activates proinflammatory signaling involving nuclear factor κB, specificity protein 1, and phosphatidylinositol 3-kinase, as well as expression of platelet-derived growth factor receptor. Activation of these pathways promotes enhanced proliferation and migration of monocytes and SMCs into the intima of the vascular wall as well as lipid accumulation and expansion of the atherosclerotic lesion. Moreover, HCMV infection induces enhanced expression of endothelial adhesion molecules and modifies the proteolytic balance in monocytes and macrophages. As a consequence, infected endothelium recruits naive monocytes from the blood stream, and the concomitant interaction between infected ECs and monocytes enables virus transfer to migrating monocytes. Endothelial damage promotes thrombin generation linking inflammation and coagulation. HCMV, in turn, enhances the thrombin generation. The virus carries on its surface the molecular machinery necessary to initiate thrombin generation, and in addition, may interact with the prothrombinase protein complex thereby facilitating thrombin generation. Thus, infection of endothelium may significantly increase the production of thrombin. This might not only contribute to thrombosis in patients with atherosclerosis, but might also induce thrombin-dependent proinflammatory cell activation. This review summarizes the existing evidence on the role of HCMV in vascular inflammation.

Thrombin and vascular inflammation.

Vascular endothelium is a key regulator of homeostasis. In physiological conditions it mediates vascular dilatation, prevents platelet adhesion, and inhibits thrombin generation. However, endothelial dysfunction caused by physical injury of the vascular wall, for example during balloon angioplasty, acute or chronic inflammation, such as in atherothrombosis, creates a proinflammatory environment which supports leukocyte transmigration toward inflammatory sites. At the same time, the dysfunction promotes thrombin generation, fibrin deposition, and coagulation. The serine protease thrombin plays a pivotal role in the coagulation cascade. However, thrombin is not only the key effector of coagulation cascade; it also plays a significant role in inflammatory diseases. It shows an array of effects on endothelial cells, vascular smooth muscle cells, monocytes, and platelets, all of which participate in the vascular pathophysiology such as atherothrombosis. Therefore, thrombin can be considered as an important modulatory molecule of vascular homeostasis. This review summarizes the existing evidence on the role of thrombin in vascular inflammation.