Репозиторий Университета

© 2020 Elsevier GmbH Lipopolysaccharides (LPSs) induce a wide spectrum of functional activities after interaction with blood cells. Effect of structure of toxic LPS from S- and Re-chemotypes of E. coli and/or non-toxic LPS of Rhodobacter capsulatus PG (R. caps.) on activation of neutrophils and monocytes of human whole blood were studied, particularly, expression of TLR4, CD14 and CD11b receptors, phagocytosis of BioParticles Alexa Fluor 488, synthesis of cytokines and chemokines. A leading role of CD11b receptor in phagocytic activity of neutrophils primed by LPS from various E. coli chemotypes was shown. The non-toxic LPS of R. caps. does not affect the efficiency of phagocytosis activity of the neutrophils. The LPS of R. caps. was shown to induce production of TRIF-dependent cytokine IFN-β in human whole blood leukocytes selectively, without activating MyD88-dependent pathway of pro-inflammatory cytokine synthesis, displaying properties of patrial agonist of TLR4. Structure and biological activity of LPS R. caps. allows considering it as a promising immunity stimulating pharmacological agent.

© 2020 Elsevier GmbH Lipopolysaccharides (LPSs) induce a wide spectrum of functional activities after interaction with blood cells. Effect of structure of toxic LPS from S- and Re-chemotypes of E. coli and/or non-toxic LPS of Rhodobacter capsulatus PG (R. caps.) on activation of neutrophils and monocytes of human whole blood were studied, particularly, expression of TLR4, CD14 and CD11b receptors, phagocytosis of BioParticles Alexa Fluor 488, synthesis of cytokines and chemokines. A leading role of CD11b receptor in phagocytic activity of neutrophils primed by LPS from various E. coli chemotypes was shown. The non-toxic LPS of R. caps. does not affect the efficiency of phagocytosis activity of the neutrophils. The LPS of R. caps. was shown to induce production of TRIF-dependent cytokine IFN-β in human whole blood leukocytes selectively, without activating MyD88-dependent pathway of pro-inflammatory cytokine synthesis, displaying properties of patrial agonist of TLR4. Structure and biological activity of LPS R. caps. allows considering it as a promising immunity stimulating pharmacological agent.

© 2018 Russian Academy of Sciences. All rights reserved. The current theoretical and experimental data about the impact of the lipid A structure on interactions of lipopolysaccharide (LPS) with serum lipid-binding protein (LBP) are presented. LBP interacts more efficiently with the LPS lipid A from Rhizobium, Escherichia, and Neisseria spp. than with the LPS lipid from Francisella, Porphyromonas, Helicobacter, Chlamydophila, as well as with the lipid A synthetic analogue-compound E5564. It is shown that the lipid A hydrocarbon chain of 14 carbon atoms is most favorable, while that of 16 carbon atoms is ultimate for interaction of LBP with lipid A. A high content of unusually long chains and branched-chain acyl residues in lipid A will further complicate the interaction of LBP with LPS. The reviewed data provide a deeper insight into the mechanisms of the LPS delivery and cell activation accomplished by serum cationic proteins such as LBP. A direct relation between the efficiency of the LBP interaction with a particular lipid A of LPS and the development of the fulminant acute inflammation is proposed.