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The disaccharide (β-D-glucopyranosyluronic acid)-(1→4)-β-D-glucopyranoside represents a repeating unit of the capsular polysaccharide of Streptococcus pneumoniae serotype 3. A conjugate of the disaccharide with BSA (di-BSA conjugate) adjuvanted with aluminum hydroxide induced - in contrast to the non-adjuvanted conjugate - IgG1 antibody production and protected mice against S. pneumoniae serotype 3 infection after intraperitoneal prime-boost immunization. Adjuvanted and non-adjuvanted conjugates induced production of Th1 (IFNγ, TNFα); Th2 (IL-5, IL-13); Th17 (IL-17A), Th1/Th17 (IL-22), and Th2/Th17 cytokines (IL-21) after immunization. The concentration of cytokines in mice sera was higher in response to the adjuvanted conjugate, with the highest level of IL-17A production after the prime and boost immunizations. In contrast, the non-adjuvanted conjugate elicited only weak production of IL-17A, which gradually decreased after the second immunization. After boost immunization of mice with the adjuvanted di-BSA conjugate, there was a significant increase in the number of CD45+/CD19+ B cells, TCR+ γδ T cell, CD5+ В1 cells, and activated cells with MHC II+ expression in the spleens of the mice. IL-17A, TCR+ γδ T cells, and CD5+ В1 cells play a crucial role in preventing pneumococcal infection, but can also contribute to autoimmune diseases. Immunization with the adjuvanted and non-adjuvanted di-BSA conjugate did not elicit autoantibodies against double-stranded DNA targeting cell nuclei in mice. Thus, the molecular and cellular markers associated with antibody production and protective activity in response to immunization with the di-BSA conjugate adjuvanted with aluminum hydroxide are IL-17A, TCR+ γδ T cells, and CD5+ В1 cells against the background of increasing MHC II+ expression., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Akhmatova, Kurbatova, Zaytsev, Akhmatova, Yastrebova, Sukhova, Yashunsky, Tsvetkov and Nifantiev.)

Pneumolysin (Ply) is a target for the development of serotype-independent pneumococcal vaccines, an important condition for the efficacy of which is their ability to activate innate immunity with the subsequent formation of adaptive immunity. In this study, the ability of recombinant full-length Ply (rPly) of pneumococci to induce TLR expression and maturation of dendritic cells generated from mouse bone marrow was evaluated. It was shown that rPly in vitro increased the number of dendritic cells expressing Toll-like receptor 4 (TLR4) on the membrane. rPly caused maturation of dendritic cells generated from mouse bone marrow, which manifested in a decrease in the number of progenitor cells (CD34), an increase in the number of cells expressing the adhesion molecule CD38, costimulatory molecules CD80 and CD86, molecules of terminal differentiation of dendritic cells CD83, as well as molecules of antigenic presentation of the major histocompatibility complex class II., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature.)

2-Aminoethyl glycoside of the pseudotetrasaccharide α-d-Glc p -(1→3)-α-l-Rha p -(1→3)-d-Rib-ol-(5- P- 2)-α-d-Gal p corresponding to a repeating unit of the Streptococcus pneumoniae type 6A capsular polysaccharide has been synthesized. A suitably protected pseudotrisaccharide α-d-Glc p -(1→3)-α-l-Rha p -(1→3)-d-Rib-ol with a free 5-OH group in the ribitol moiety and a 2-OH derivative of 2-trifluoroacetamidoethyl α-d-galactopyranoside have been efficiently prepared and then connected via a phosphate bridge using the hydrogen phosphonate procedure. Preliminary immunological evaluation of this pseudotetrasaccharide and the previously synthesized pseudotetrasaccharide corresponding to a repeating unit of the capsular polysaccharide of S. pneumoniae serotype 6B has shown that they contain epitopes specifically recognized by anti-serogroup 6 antibodies and are able to model well the corresponding capsular polysaccharides. Conjugates of the synthetic pseudotetrasaccharides with bovine serum albumin were shown to be immunogenic in mice., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Sukhova, Yashunsky, Kurbatova, Akhmatova, Tsvetkov and Nifantiev.)

A number of studies have demonstrated the limited efficacy of S. pneumoniae type 3 capsular polysaccharide (CP) in the 13-valent pneumococcal conjugate vaccine against serotype 3 invasive pneumococcal diseases and carriage. Synthetic oligosaccharides (OSs) may provide an alternative to CPs for development of novel conjugated pneumococcal vaccines and diagnostic test systems. A comparative immunological study of di-, tri-, and tetra-bovine serum albumin (BSA) conjugates was performed. All oligosaccharides conjugated with biotin and immobilized on streptavidin-coated plates stimulated production of IL-1 α , IL-2, IL-4, IL-5, IL-10, IFN γ , IL-17A, and TNFα, but not IL-6 and GM-CSF in monocultured mice splenocytes. The tetrasaccharide-biotin conjugate stimulated the highest levels of IL-4, IL-5, IL-10, and IFN γ , which regulate expression of specific immunoglobulin isotypes. The tetra-BSA conjugate adjuvanted with aluminum hydroxide elicited high levels of IgM, IgG1, IgG2a, and IgG2b antibodies (Abs). Anti-CP-induced Abs could only be measured using the biotinylated tetrasaccharide. The tetrasaccharide ligand possessed the highest binding capacity for anti-OS and antibacterial IgG Abs in immune sera. Sera to the tetra-BSA conjugate promoted greater phagocytosis of bacteria by neutrophils and monocytes than the CRM 197 -CP-antisera. Sera of mice immunized with the tetra-BSA conjugate exhibited the highest titer of anti-CP IgG1 Abs compared with sera of mice inoculated with the same doses of di- and tri-BSA conjugates. Upon intraperitoneal challenge with lethal doses of S. pneumoniae type 3, the tri- and tetra-BSA conjugates protected mice more significantly than the di-BSA conjugate. Therefore, it may be concluded that the tetrasaccharide ligand is an optimal candidate for development of a semi-synthetic vaccine against S. pneumoniae type 3 and diagnostic test systems., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Kurbatova, Akhmatova, Zaytsev, Akhmatova, Egorova, Yastrebova, Sukhova, Yashunsky, Tsvetkov and Nifantiev.)

Pregnancy is a condition of modulated immune suppression, so this group of patients has increased risk of infectious diseases. Trivalent subunit vaccines, unadjusted Agrippal S1 (group I) and immunoadjuvant Grippol Plus (group II), containing 5 μg of actual influenza virus strains, were administered respectively to 37 and 42 women in the second and third trimester of physiological pregnancy. The administration of subunit influenza vaccines was accompanied by the development of local reactions in no more than 10% of patients, compared with 4.9% of the 41 pregnant women in the placebo group (group III). Systemic reactions were of a general somatic nature, did not differ between vaccinated and placebo groups, and were not associated with vaccination. Physiological births in groups I, II and III were 94.6%, 92.9% and 85.4%, respectively, and the birth rates of children without pathologies were 91.9%, 90.5% and 80.5%, respectively, and were comparable between groups. Vaccination stimulated the production of protective antibodies against influenza virus strains in 64.8-94.5% of patients after immunisation with an unadjusted vaccine and in 72.5-90.0% of patients after the administration of an immunoadjuvant vaccine. After 9 months, antibody levels were recorded in 51.3-72.9% in group I and 54.2-74.2% in group II. Immunisation against influenza in pregnant women provided a high level of seroprotection and seroconversion. Nevertheless, the level of seroprotection against the influenza strain A(H3N2, Victoria) was slightly lower in the group immunised with an unadjusted vaccine compared to those vaccinated with the immunoadjuvant vaccine., Competing Interests: Conflict of interest: None declared.

Identifying protective synthetic oligosaccharide (OS) epitopes of Streptococcus pneumoniae capsular polysaccharides (CPs) is an indispensable step in the development of third-generation carbohydrate pneumococcal vaccines. Synthetic tetra-, hexa-, and octasaccharide structurally related to CP of S. pneumoniae type 14 were coupled to bovine serum albumin (BSA), adjuvanted with aluminum hydroxide, and tested for their immunogenicity in mice upon intraperitoneal prime-boost immunizations. Injections of the conjugates induced production of opsonizing anti-OS IgG1 antibodies (Abs). Immunization with the tetra- and octasaccharide conjugates stimulated the highest titers of the specific Abs. Further, the tetrasaccharide ligand demonstrated the highest ability to bind OS and CP Abs. Murine immune sera developed against tetra- and octasaccharide conjugates promoted pathogen opsonization to a higher degree than antisera against conjugated hexasaccharide. For the first time, the protective activities of these glycoconjugates were demonstrated in mouse model of generalized pneumococcal infections. The tetrasaccharide conjugate possessed the highest protective activities. Conversely, the octasaccharide conjugate had lower protective activities and the lowest one showed the hexasaccharide conjugate. Sera against all of the glycoconjugates passively protected naive mice from pneumococcal infections. Given that the BSA-tetrasaccharide induced the most abundant yield of specific Abs and the best protective activity, this OS may be regarded as the most promising candidate for the development of conjugated vaccines against S. pneumoniae type 14 infections.

Aim: Evaluate cytokine status in patients with malignant liver cells after surgery., Materials and Methods: 33 patients aged 35 to 76 years were included into the study. Blood was obtained before the operation and in the post-operation period: after 6 and 24 hours and at day 7 Cytokine profile (IL-Ib, IL-2, TNF-α, IFN-γ, IL-12p70, IL-4, IL-5,IL-6, IL-10, IL-13, IL-9, I-17a, IL-22) was evaluated using Multiplex- 13 system (Bender MedSystems, Austria)., Results: In patients levels of all the studied cytokines (Thl/Th2/Th9/Thl7/Th22) were already increased before the operations, that gives evidence of the presence of an inflammatory proc- ess connected with activation of immune system effectors., Conclusion: Disbalance of cytokine system helper cells resulting in functional and organic alterations through induction of the "cytokine storm" may aggravate the state of these patients. Further studies on the correction of cytokine system in these patients are thus needed.

Aim: Study subpopulation structure of lymphocytes in healthy individuals under the effect of various influenza vaccines in an in vitro system., Materials and Methods: Evaluation of immune- phenotype features of PBMCs, activated in vitro by immune-adjuvanted and unadjuvanted vaccines against influenza in healthy individuals, was carried out by using flow cytometry method., Results: Grippol plus vaccine caused a more pronounced stimulating effect compared with subunit and split-vaccines on NK-cells, cells with markers of early activation CD45/CD25, induced the quantity of natural regulatory cells (CD4/CD25/Foxp3), increase of the number of B-cells and reduced the amount of cell types with apoptosis marker CD45/CD95., Conclusion: Immune-adjuvanted vaccine Grippol plus induced formation of effectors of both innate and adaptive immunity and possessed the most powerful potential regarding activation of various types of immune-competent cells compared with unadjuvanted vaccines.

Aim: Evaluation ofthe ability of capsule polysaccharides (CP) of Streptococcus pneumoniae serotype 3 and 14 and their synthetic structure analogues, conjugated with bovine serum albumin (BSA), to detect antibodies in post-vaccination sera of mice. Materials andmethods. Oligosaccharides correspond- ing to one, one and a half and two repeating links of serotype 3 and 14 S. pneumoniae CP were synthe- sized, their conjugates with BSA were produced by squarate method as well. Ligand content-per BSA molecule was controlled by MALDI-TOF spectrometry. Immune sera were obtained after 2 intraperi- toneal administrations to mice of glucoconjugates adsorbed on aluminum hydroxide or 13-valent pneumococcal conjugated vaccine. Determination of levels of post-vaccination class G antibodies and their sub-isotypes was carried out in EIA., Results: Immunization of mice with neoglucoconjugates resulted in formation of predominantly IgGl recognizing serotype 3 and 14 S. pneumoniae C. IgG1 in mice immunized with a 13-valent conjugated vaccine recognized serotype 3 S. pneumoniae CP, but detected serotype 14 S. pneumoniae CP weakly. All the conjugated synthetic oligosaccharides were characterized by a high ability to bind antibodies in blood of mice immunized with the polysaccharide conjugated vaccine. BSA-tetrasaccharide of serotype 3 S. pneumoniae and BSA-tetrasaccharide of serotype 14 S.pneumoniae were characterized by the highest ability to detect IgG1 against C., Conclusion: Synthetic oligosaccharides, conjugated with BSA protein-carrier, may be used to develop diagnostic test-systems for determination of antibodies in post-vaccination sera.

Aim: Study the effect of Vaxigrip split, Influvac subunit and Grippol plus immune-adjuvanted vaccines on the content of myeloid (mDC) and plasmacytoid (pDC) dendritic cells (DC) in blood of vaccinated healthy women. Materials andmethods. Blood of 30 healthy women aged 18-50 years was studied at days 7 and 30 after the vaccination. pDC (CD14+CD16-/CD85k(ILT3)-PE/ CD123-PC5) and mDC (CD14+CD-16-/CD85k(ILT3)-PE/CD33 -PC5) immune phenotyping was carried out using mAbs (Beckman Coulter, France) and flow cytometer Cytomix FC-500 (Beckman Coulter, USA)., Results: Use of unadjuvanted vaccines Vaxigrip and Influvac resulted in an increase of the numbers of mDC and pDC (p<0.05) in blood of the vaccinated only at day 7 of the observation. Grippol resulted in a more significant (2.2 - 3.6 times, p<0.05) increase of DC subpopulations (compared with unadjuvanted vaccines) at both day 7 and a month after the vaccination., Conclusion: Influenza vaccination activated innate effectors - the first component on the way of infection penetration - dendritic cells of both myeloid and lymphoid origin. Wherein, a more pronounced and prolonged effect of such activation is observed when immune-adjuvanted vaccine is used compared with subunit and split vaccines.