[The use of immunoglobulins and monoclonal antibodies against COVID-19].

INTRODUCTION: When a new disease occurs, one of the most affordable remedies is drugs containing specific antibodies to this infectious agent. The use of such drugs is aimed at reducing the amount of the pathogen in the macroorganism and the associated reduction in the severity of the symptoms of the disease or recovery. The purpose of this review is to analyze the experience of using immunoglobulins and monoclonal antibodies in the treatment of COVID-19 patients during the pandemic. RESULTS AND CONCLUSION: The two main groups of medical protective agents that block the penetration of the SARS-CoV-2 virus into permissive cells are drugs obtained from blood plasma of convalescents (immunoglobulin) and human monoclonal antibodies. The first group of drugs in the treatment of COVID-19 includes blood plasma of convalescents, which can be successfully used for emergency prevention. The main disadvantage of using blood plasma convalescents is the difficulty of standardization due to the different content of specific antibodies in donors. Another disadvantage is the undesirable side effects in recipients that occur after plasma administration. An alternative approach to COVID-19 therapy is the use of humanized and genetically engineered human monoclonal antibodies against certain epitopes of the SARS-CoV-2 virus. For example, monoclonal antibodies against receptor-binding domain of the S-protein, which prevents the virus from entering permissive cells and interrupts the development of infection. The advantages of these drugs are their safety, high specific activity, and the possibility of standardization. However, the complexity of their production and high cost make them inaccessible for mass use in practical medicine.

[Sensitivity and specificity of the ELISA Kit for the detection of antidobies to Junin virus].

The goal of this work was to describe methodological approaches to determination of sensitivity and specificity of the enzyme-linked immunosorbent assay kit (ELISA Kit) for detection of the specific anti-Junin virus (JV) antibody. Comparison of ELISA to plaque reduction neutralization test (PRNT) showed direct relationship between antibody titers in the samples of serum of immunized animals, determined by either PRNT or ELISA methods. The obtained results provided an opportunity to form the panels of positive and negative serum samples to determine the sensitivity and specificity of the ELISA Kit. Sensitivity of the ELISA Kit was at least 98% when studying the samples of serum of immunized guinea pigs and rabbits (determined as positive in PRNT). The sensitivity of the ELISA Kit was at least 68% when studying the samples determined by PNRT as uncertain positive. The specificity was 98%. The specificity of the ELISA Kit was 98%.

[Study of sensitivity of laboratory animals to a causative agent of argentine hemorrhagic fever].

AIM: Study sensitivity of laboratory animals to a causative agent ofArgentine hemorrhagic fever. MATERIALS AND METHODS: Junin virus strain XJ P37 was obtained from the State Collection of Causative Agents of Viral Hemorrhagic Fevers of the Pathogenicity Group I of Scientific Research Center of the 33rd Central Scientific Research Test Institute (SRC of the 33rd CSRTI). Junin virus strain XJ P37 culture with biological activity of 5.2 1g PFU x ml was used in the experiments. Mice (2 - 4 and 7 - 14 days old), guinea pigs (250 - 300 g), 1.8 - 2.5 kg shinshilla breed rabbits, 2.0 - 3.0 kg javanese macaque monkeys were obtained from vivarium of the SRC of the 33rd CSRTI. Vero (B) and GMK-AH-1 (D) cell cultures were obtained from cell culture collection of the SRC of the 33rd CSRTI. Biological activity calculation of Junin virus was carried out by Kerber in I.P. Amsharin modification. RESULTS: Lethality in animals was from 12.5 to 50% after intranasal and intraperitoneal infection of guinea pigs, intramuscular, intraperitoneal and subcutaneous infection of rabbits, intracerebral and intranasal infection of mice at the doses from 0.4 to 1.0 x 10(5) PFU. Death of infected monkeys after intramuscular administration of the virus at 1.0 x 10(4) PFU dose was not observed. In 100% of surviving animals formation of virus-neutralizing antibodies was registered. CONCLUSION: Evaluation of sensitivity of laboratory animals to Junin virus has shown that intracerebrally infected mice may be used to maintain causative agent culture, infected guinea pigs - to prepare virus-containing cultures and modelling infection exacerbation in humans. Intramuscularly infected rabbits may be used to obtain hyper-immune sera.

[Optimization of conditions of quantitative evaluation of argentine hemorrhagic fever causative agent].

AIM: Optimization of conditions of quantitative evaluation of Argentine hemorrhagic fever causative agent. MATERIALS AND METHODS: Junin virus (XJ P37 strain) was obtained from National collection of viral hemorrhagic fever causative agents of the 1st pathogenicity group of the 33rd Central Research Testing Institute. Junin virus (XJ P37 strain) culture with biological activity of 5.2 lg PFUxm(-1) was used in the experiments. Vero B, 6619-1(D) and GMK-AH-1(D) were obtained from collection of cell culture of the Research Scientific Centre of the 33rd Central Research Testing Institute. Calculation of biological activity of Junin virus during titration in cell cultures was carried out by Kerber method with modification by I.P. Ashmarin. RESULTS: During incubation for 4 - 7 days after the infection of cell monolayer the determined biological activity was 4.4 - 6.4 lg PFUxml(-1); the size of the formed negative colonies--(1.5 +/- 0.5) mm. CONCLUSION: The conditions of quantitative evaluation of Argentine hemorrhagic fever were optimized by negative colonies method (using 5 - 7 day Vero B cell culture monolayer with staining of monolayer on day 5 of secondary incubation, recording of results at day 7 after the infection).

[Stabilization of peroxidase conjugates used in enzyme immunoassay systems to detect Ebola and Marburg virus antigens].

The time course of changes in the activity of solutions of horseradish peroxidase conjugates with immunoglobulins against Ebola and Marburg fevers was studied in the presence of different components. The series of the conjugates of ELISA kits for the detection of Ebola and Marburg virus antigens, which were prepared on the basis of the designed stabilizing solution, preserved at less than 90% of its baseline activity during 10 months at a storage temperature of 2 to 8 degrees C.

[Application of heat shock proteins as stress markers in aquatic organisms using endemic Baikal amphipods as an example].

When heat shock proteins (HSPs) are used as biomarkers in monitoring studies of aquatic ecosystems, it is necessary to take into account the specificity of synthesis of these proteins in various organisms. This especially applies to endemic species and species with narrow ranges of adaptation for specific conditions in certain water bodies. In this study, we assessed the possibility to use HSPs as molecular stress markers in species with a narrow niche breadth using endemic Baikal amphipods (Crustacea, Amphipoda) as an example. The effect of stress induced by toxicants and temperature has been assessed. Proteins of families HSP70 and low-molecular-weight HSP related to alpha-crystallins were used as biomarkers. Temperature- and toxicant-induced stresses induced low-molecular-weight HSP synthesis in the endemic amphipod species studied. However, induction of HSP70 synthesis in the same species after temperature stress has not been detected. The specificity of synthesis of HSP70 is discussed. The results obtained in this study suggest that low-molecular-weight HSPs can be used as stress markers in Baikal species and species with a narrow niche breadth.