Encapsulated Hsp70 decreases endotoxin-induced production of ROS and TNFα in human phagocytes.

Human heat shock protein Hsp70 was experimentally inserted into polyelectrolyte microcapsules. Encapsulated recombinant Hsp70 was studied in terms of its effects on neutrophil apoptosis, the production of reactive oxygen species, and the secretion of tumor necrosis factor alpha by promonocytic THP-1 cells. It was found that encapsulated Hsp70 effectively inhibits neutrophil apoptosis, unlike free exogenous protein used in solution. In THP-1 cells, encapsulated and free Hsp70 reduced LPS-induced tumor necrosis factor alpha production with a similar efficiency. Encapsulated Hsp70 reduces LPS-induced reactive oxygen species production by neutrophils in the course of its release from the microcapsules but not as much as free Hsp70. Thus, the polyelectrolyte microcapsules can be used as containers for the effective delivery of Hsp70 to neutrophils and monocytes to significantly improve the functioning of the innate immune system.

Influence of encapsulated heat shock protein HSP70 on the basic functional properties of blood phagocytes.

Microencapsulated heat shock proteins HSP 70 were studied in terms of their effects on neutrophil apoptosis, production of reactive oxygen species, and secretion of TNF-α by human neurtrophils and monocytes. Encapsulated HSP70 inhibited neutrophil apoptosis by 65% as compared to the effect of nonencapsulated HSP70; TNF-α production by the promonocytic THP-1 cells was similarly inhibited by the non-encapsulated and encapsulated HSP70. Thus, the polyelectrolyte micromolecules can be used as containers for effective delivery of HSP70 up to neutrophils and monocytes to correct the innate immunity functions.

[Inclusion of proteins into polyelectrolyte microcapsules by coprecipitation and adsorption].

In present study microcapsules composed of synthetic (PSS and PAA) and biodegradable (DS and PAr) polyelectrolytes on calcium carbonate microparticles were obtained. The ultrastructural organization of biodegradable microcapsules was studied using transmission electron microscopy. The envelope of such capsules consisting of six polyelectrolyte layers is already well-formed, having the average thickness of 44 ± 3.0 nm, and their internal polyelectrolyte matrix is sparser compared to the synthetic microcapsules. Spectroscopy was employed to evaluate the efficiency of incorporation of FITC-labeled BSA into synthetic microcapsules by adsorption, depending on the number of polyelectrolyte layers. It was shown that the maximal amount of protein incorporated into the capsules with 6 or 7 polyelectrolyte layers (4 and 2 pg/capsule, correspondingly). As a result we conclude that, in comparison with co-precipitation, the use of adsorption allows to completely avoid the loss of protein upon encapsulation.

[Effect of oxygen on gamma-radiation damage to nucleic acids irradiated in media with different pH values]. / Vliianie kisloroda na gamma-radiatsionnoe povrezhdenie nukleinovykh kislot, obluchennykh v sredakh s razlichnym znacheniem pH.

The injury to DNA and RNA exposed to gamma-radiation in media of varying acidity with oxygen present or absent therein has been investigated. The interaction of the protonated base with a superoxide radical has been shown to contribute markedly to the oxygen effect of the radiation injury to nucleic acids.

[The role of protons in a medium in gamma-radiation-induced damage of nucleic acids]. / Rol' protonov sredy v gamma-radiatsionnom povrezhdenii nukleinovykh kislot.

The study of the combined effect of gamma-radiation and acid medium (pH 7.0-2.0) on DNA and RNA showed that the radiation-induced injury to nucleic acids increased with increasing concentration of H+-ions in the medium up to pH values below which protons exerted a protective action. Irradiation of native DNA in acid medium, as compared to neutral one, increased not only the number of injured bases but also the average size of the induced local defect in the secondary structure. It was shown that the proton sensitization was determined both by the number of protonated bases and by the degree of ordering the polynucleotide chain.

[Mechanism of the radiation damage to the secondary structure of DNA]. / Mekhanizm radiatsionnogo narusheniia vtorichnoi struktury DNK.

The authors describe the mechanism of radiation-induced damage of a secondary DNA structure suggesting that a double-helical brim conformation adjacent to a local defect in the secondary structure, and the thermoactivated threshold process of a "confluence" of the defects are present in the irradiated DNA. It is supposed that the major type of the radiation damage to the spatial DNA structure is a triple helix repaired with the aid of the specific endonuclease.