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The aim of the research was to compare in vitro characteristics of reception of the natural diphtheria toxin — DT and its nontoxic recombinant analogs — toxoids. For assessing ligand-receptor interaction the method of immunoenzyme analysis and ELISA was used, where the bonding layer recombinant analogues of diphtheria toxin cell receptor HB-EGF from sensitive and resistant to the toxin of the organisms were served. According to the results of ELISA the natural diphtheria toxin, in contrast to recombinant toxoids — CRM197, and B subunit, interacted with mouse HB-EGF with a very low affinity. While human HB-EGF with an equally high affinity connected as toxoids as native diphtheria toxin. Therefore, the analyzed recombinant analogs of toxin obtained in E. coli cells did not reproduce in full measure the receptor specificity of the natural toxin, which should be considered in the case of using these proteins as biotech products., Целью работы было сравнение in vitro особенностей рецепции природного дифтерийного токсина — ДТ и его нетоксичных рекомбинантных аналогов — токсоидов. Для оценки лиганд-рецепторного взаимодействия применяли метод иммуноэнзимного анализа ELISA, где в качестве связующего слоя использовали рекомбинантные аналоги клеточного рецептора дифтерийного токсина HB-EGF от чувствительных и резистентных к токсину организмов. По результатам ELISA природный дифтерийный токсин, в отличие от рекомбинантных токсоидов — CRM197 и субъединицы В, взаимодействовал с HB-EGF мыши с очень низкой афинностью. При этом HB-EGF человека с одинаково высокой афинностью связывал как токсоиды, так и нативный дифтерийный токсин. Таким образом, исследованные рекомбинантные аналоги токсина, полученные в клетках E. сoli, не воспроизводили в полной мере рецепторной специфичности природного токсина, что следует учитывать в случае использования этих протеинов как биотехнологических продуктов.

The antibody responses to the recombinant analogs of Mycobacterium bovis antigens rMPB63 and rMPB83, as well as to tuberculin PPD, were determined in 96 bovine blood serum specimens. A statistical approach based on the approximation with multiple Gaussian curves with Levenberg-Marquardt algorithm was proposed for analysis of the distribution of antibody levels to the studied antigens. The results demonstrate that the recombinant MPB63 and MPB83 antigens along with the traditionally used PPD are appropriate for designing the test kits for diagnosing bovine tuberculosis at a herd level.

Multiple sclerosis (MS) is a chronic autoimmune demyelinating disorder of the central nervous system. Nowadays some disease-modifying drugs (DMD) in the Russian Federation (RF) are biosimilars. Their full spectrum of tolerability and efficacy is to be determined. Here we present results of two retrospective-prospective studies on efficacy and safety of a biosimilar interferon beta-1a (genfaxon) in treatment of MS in the RF.determination of safety and efficacy profile of genfaxon in a routine neurological practice in the RF.Trials were performed in 18 MS centers in the RF. A total of 649 patients aged from 18 to 68 years with the EDSS score no more than 6.0 were treated with genfaxon for 12 months. The first group was comprised of 'naïve' patients without previous history of DMD administration. There were patients in the second group which have already received some of DMD. Statistical analysis was performed with the help of significance criteria (χ-square), t-criteria of Student for analysis of independent samplings.There were no serious adverse events during the period of the study. "Naïve" patients had significantly lower number of adverse events, than patients with previous history of DMD usage. Efficacy results were comparable with results published for the Rebif.Data, received from the studies show equal efficacy and tolerability of genfaxon compared with original DMD Rebif.

Aim. To select scFv which have an ability to neutralize diphtheria toxin. Methods. Flow-cytometry was used to study the ability of specific scFv to block the binding of a labeled receptor binding fragment of toxin with a surface of sensitive to toxin cells. Results. Four scFv with toxin-neutralization properties were selected. Conclusions. The obtained scFv could be considered as promising candidates for antitoxic antidiphtheria drugs of new generation.