ЩО НАСПРАВДІ ОЗНАЧАЄ ТЕСТУВАННЯ НА КОРОНАВІРУС ДЛЯ ПАЦІЄНТА?

Testing for COVID has become one of the common day activities during pandemic days, often like a visit to dentist or family doctor. However, there are many types of tests with different principles, sensitivities, specificities, and diagnostic windows. And since the COVID disease has a great impact on our social life, changing our behavior, social contacts, and attitude, the incorrect treatment of «test for COVID» can have deteriorating results. The «COVID test» is seldom interpreted correctly due to multiple technologies, ways of testing, sensitivities and even influence of social media. Here we in a simple form summarize the most common detection methods with their peculiarities in the form of Q&A which typical patients can have. We discuss RT-qPCR, POC express tests, ELISA testing for IgG, IgM antibodies, as well as present our data regarding the longevity of blood antibody titers against coronaviral antigens.Пандемія коронавірусного захворювання внесла в наше повсякденнe життя термін «тест на коронавірус», і при цьому не один, а цілу їх різноманітність. Результати «тесту на COVID» рідко трактуються правильно і породжують багато неправильних уявлень у пацієнта, впливаючи як на соціальну діяльність, так і на фізичне самопочуття. Тому ми хотіли звернути увагу на трактування результатів основних типів тестів, які подаємо у доступній формі «запитання-відповідь». Ми обговорюємо принципи детекції, тести ЗТ-кПЛР, антитіла IgG, IgM, експрес-тести, а також наводимо дані наших оригінальних досліджень щодо тривалості імунної відповіді до коронавірусних антигенів

Blood serum immunoglobulins of patients with multiple myeloma are capable of hydrolysing histone H1

Background: Recently we have shown that the imunoglobulins G from blood serum of some multiple sclerosis patients are capable of cleaving histone H1. Aim: To check whether histone H1-hydrolyzing abzymes could be detected not only in blood plasma of autoimmune patients, but also during cancer development, particularly during the onset of multiple myeloma. Methods: Immunoglobulines were isolated from blood serum of multiple myeloma patients (n = 11) by precipitation with 50% ammonium sulfate and tested for proteolytic activity toward linker and core calf thymus histones. Antibody preparations able to cleaved histone H1 were subjected to affinity chromatography on histone H1-Sepharose with following analysis of chromatographic fractions’ protease activity. To prove that antibody molecules are responsible for hydrolysis of histone H1, gel filtration at acidic pH with subsequent examination of protease activity of chromatographic fractions (pH-shock analysis) was used. Results: It was found that 3 of 11 antibody preparations are capable of hydrolyzing calf thymus histone H1 but not core histones. It was shown that histone H1-hydrolysing activity of 2 proteolytically active antibody preparations is associated with IgGs that possess affinity towards histone H1. pH-shock analysis proved that protease activity towards histone H1 is intrinsic property of IgG molecules. Conclusions: We demonstrated the existence of previously unknown histone H1 hydrolyzing IgG abzymes in the serum of multiple myeloma patients. Possible biological role of hisH1-hydrolyzing antibodies in patients with multiple myeloma was discussed

Interaction of 4 allotropic modifications of carbon nanoparticles with living tissues

Environmental pollution and technological progress lead to carbon nanoparticles that pose a serious health risk. They are present in soot, dust, and printing toner and can also be formed during grinding and cutting. Human neutrophils are able to sequester foreign material by formation of neutrophil extracellular traps (NETs), a process that can cause a strong inflammatory response. In the current work we compared proinflammatory properties of different carbon-based nanostructures: nanodiamonds, graphene oxide, fullere­nes C60 and carbon dots. We tested adjuvant properties of carbon nanoparticles in a murine immunization model by investigating humoral (specific IgG and IgM antibodies) and cellular (delayed type hypersensitivity) immune responses. The ability of NETs to sequester nanoparticles was analyzed in a mouse air pouch model and neutrophil activation was verified by in vivo tracking of near-infrared labeled nanodiamonds and ex vivo fluorescent assays using human blood-derived neutrophils. All carbon nanoparticles exhibited proinflammatory adjuvant-like properties by stimulating production of specific IgG but not IgM antibodies (humoral immune response). The adjuvant-like response decreased in this order: from nanodiamonds, graphene oxide, fullerenes C60 to carbon dots. None of the studied carbon nanoparticles triggered a delayed type hypersensitivity reaction (cellular immune response). Nanodiamonds and fullerenes C60 were sequestrated in the body by NETs, as confirmed in the air pouch model and by in vivo fluorescent tracking of near-infrared labeled nanodiamonds

Proapoptotic changes of erythrocytes Danio rerio influenced by copper cations

Toxic effect of the cations of copper of aquatic surrounding in the concentration 0.75 mg/l during four days on Danio rerio fishes is revealed as the increase in the amount of erythrocytes of peripheral blood with micronucleus and double nuclei. In addition, the characteristic signs of apoptosis in blood cells where observed, particularly externalization of phosphatidyl serine, determined by annexin V staining, increase in the intensity of binding of galactose-specific RCA lectin and mannose-specific NPL lectin, suggesting the increase of the level of exposure for corresponding surface glycoside residues on the cell surface, and also internucleosomal DNA fragmentation. The importance of the utilization of the metods of the apoptotic cells detection in fish for the study of xenobiotic influence on the organism was proved

Sialylation of anti-histone antibodies in blood serum of systemic lupus erythematosus patients

Anti-histone autoantibodies belong to main marker antibodies used in the diagnostics of systemic lupus erythematosus (SLE) patients. During autoimmune diseases, especially in SLE, prevalent process of inflammation is caused by high titers of auto-antibodies. It is known that the level of IgG sialylation affect their anti-inflammatory properties. The aim of the experiments was to investigate the level of sialylation of anti-histone IgG-antibodies from blood serum of patients with SLE. Investigation was carried out by two methodological approaches. In the first case, the antibodies were purified from blood serum by affine chromatography on histone-Sepharose and protein G-Sepharose followed by Western blot detection of sialic acid residues in the carbohydrate chaines of IgG molecules using sialospecific previously biotinylated Sambucus nigra lectin (SNA). In the second case, IgG-antibodies were isolated from blood serum by affine chromato­graphy on protein G-Sepharose, this fraction was separated on sialylated and not sialy­lated IgG by SNA-Sepharose chromatography followed by checking their affinity to histones by ELISA. In this manuscript, it is shown that the level of sialylation of anti-histone IgG is lower than in control preparation of antibodies. Our data showed that anti-histone autoantibodies are devoid of sialic acid residues at the ends of the carbohydrate chains of Fc-fragments promote their inflammatory properties in patients with SLE

Apoptotic modification of glycosphingolipids of human granulocytes

The phenomenon of programmed apoptotic desialylation of cell glycans was described previously. However, the possibility of this process application to the sialylated glycolipids of membranes stayes unknown. Granulocytes of human peripherical blood were utilized as a model for studying glycosphingolipid spectra changes. Ganglioside fractions were extracted from the granulocytes and purified by two-stage column chromatography – DEAE-Fractogel and Sephadex LH-20 sorbents, with subsequent analysis by thin-layer and high-performance liquid chromatography. An increased level of GM2, GM1 ganglioside and Gb3 globoside in apoptotic cells, as well as a decrease of GM3, GT3 and Gb4 amount were detected. These results draw to a conclusion that gangliosides, as well as N-glycans, might be a target of apoptotic desialylation. Accor­ding to available recent data, changes in gangliosides can serve as important pathoge­nesis factors in the autoimmune disorders

Simple two-step covalent protein conjugation to PEG-coated nanocrystals

Covering of nanocrystals (NC) with a polyethylene glycol (PEG) envelop is a common way to increase their hydrophilicity, and compatibility with bio-systems, including increased retention time in the body. Colloidal semiconductor NC, also known as quantum dots (QD), particularly benefit from covering with PEG due to passivation of the inorganic core, while maintaining physical properties of the core. Despite many advantages of covering the surface with PEG, the covalent attachment of protein to hydroxyls of PEG is complicated. Here we propose a simple two-step approach for modification of PEG residues with subsequent covalent attachment of proteins. We were able to achieve specific NC targeting by means of attached protein as well as preserve their optical parameters (fluorescence intensity) in chemical reaction conditions. In the optimized protocol, ensuring removal of chemical byproducts by dialysis, we were able to omit the need for centrifugation (usually a limiting step due to particle size). The obtained NC-protein conjugate solutions contained 0.25x of initial unmodified NC amount, ensuring a low dilution of the sample. During all reactions the pH range was optimized to be between 6 to 8. The proposed approach can be easily modified for covalent targeting of different PEG-covered nanocomposites with proteins