Optimization of cold-adapted alpha-galactosidase expression in Escherichia coli

α-Galactosidase (α-PsGal) of the cold-adapted marine bacterium Pseudoalteromonas sp. KMM 701 was cloned into the pET-40b(+) vector to study its properties and to develop an effective method for modifying human B-erythrocytes into O-blood group. The use of heat-shock as a pre-induction treatment, IPTG concentration of 0.2 mM and post-induction cultivation at 18 °C for 20 h in the developed MX-medium allowed increasing the recombinant Escherichia coli Rosetta (DE3)/40Gal strain productivity up to 30 times and the total soluble α-PsGal yield up to 40 times.

[ADENOVIRUSES IN THE ETIOLOGICAL STRUCTURE OF ACUTE RESPIRATORY VIRAL INFECTION IN MOSCOW IN 2004 - 2014]

AIM

Study prevalence of adenovirus species and serotypes that had caused acute respiratory viral infection (ARVI) in Moscow in 2004 - 2014.

MATERIALS AND METHODS

Material from respiratory tract of 4731 patients with ARVI and 663 conditionally healthy children and adults was used. ARVI causative agents were detected by PCR with real-time detection using AmpliSens reagent kits (CRIE, Moscow). Membership of adenoviruses to a certain serotype was determined by sequencing of hexon gene segment. Adenoviruses that had caused ARD in servicemen in 2010 - 2014 were also studied.

RESULTS

ARVI causative agents were detected in 64.6% ill children and 58% of adults. Respiratory-syncytial and rhinoviruses prevailed in children, influenza A virus--in adults. Adenoviruses were detected in 6.9% of ill children and 2.9% of adults during the whole year, with a rise in October-December. B and C species occurred at an equal frequency, E species was found less often. Serotypes 3 and 2 prevailed in 34% and 21% of cases of adenovirus mono-infection, respectively, serotypes 7, 6 and 4 occurred less often. 4 out of 5 outbreaks of adenovirus infection in servicemen were caused by serotype 7. Adenoviruses were absent in the group of healthy adults, in conditionally healthy children were detected in 0.4% of cases and were attributed to serotypes 1 and 2.

CONCLUSION

Etiological structure of ARVI was studied for the last decade. Adenovirus infection ranked 5th in children and 7th in adults. 9 serotypes of 3 species of respiratory adenoviruses were identified. Varying prevalence of species and serotypes depending in season, clinical diagnosis and patient age was demonstrated.

Cucumarioside E from the Far Eastern Sea Cucumber Cucumaria japonica (Cucumariidae, Dendrochirotida), New Minor Monosulfated Holostane Triterpene Pentaoside with Glucose as the Second Monosaccharide Residue

New minor triterpene glycoside, cucumarioside E (1) has been isolated from the Far Eastern sea cucumber Cucumaria japonica. The structure of the glycoside was elucidated by 2D-NMR specroscopy and mass-spectrometry. The glycoside has glucose instead of quinovose as the second monosaccharide residue and xylose as third monosaccharide residue that is unique structural feature for triterpene glycosides carbohydrate chains from sea cucumbers belonging to the genus Cucumaria.

The influence of monogalactosyldiacylglycerols from different marine macrophytes on immunogenicity and conformation of protein antigen of tubular immunostimulating complex

The tubular immunostimulating complex (TI-complex) is a novel nanoparticulate antigen delivery system consisting of cholesterol, triterpene glycoside cucumarioside A(2)-2, and glycolipid monogalactosyldiacylglycerol (MGDG) isolated from marine macrophytes. MGDG is crucial for the formation of a lipid matrix for the protein antigen incorporated in TI-complexes. Fatty acid composition and the physical state of this glycolipid depend on the taxonomic position of marine macrophytes. Therefore, the aim of the present work was to study the capacity of MGDGs, isolated from five species of marine macrophytes, to influence conformation and to enhance immunogenicity of porin from Yersinia pseudotuberculosis (YOmpF) as a model antigen of subunit vaccine based on TI-complexes. The trimeric porin was chosen for these experiments, because it was approximately two times more immunogenic than monomeric porin incorporated in TI-complexes. Immunization of mice with YOmpF within TI-complexes, comprised of different MGDGs, revealed a dependence of the immunostimulating effect of TI-complexes on the microvicosity of this glycolipid. TI-complexes comprising MGDGs from Sargassum pallidum and Ulva fenestrata with medium microviscosity induced maximal levels of anti-porin antibodies (four times higher when compared with those induced by pure porin). The adjuvant effect of TI-complexes based on other MGDGs varied by 2.8, 2.3 and 1.3 times for TI-complexes comprised of MGDGs from Zostera marina, Ahnfeltia tobuchiensis, and Laminaria japonica, respectively. MGDGs are also able to influence cytokine mechanisms of immunological regulation. DSC and spectroscopic studies showed that maximal immunostimulating effect of TI-complexes correlated with a moderate stabilizing influence of MGDGs from S. pallidum and U. fenestrata on the conformation of porin. The results obtained suggest lipid "nanofluidics" as a novel strategy for optimizing the immune response to protein antigens within lipid particulate systems.