Enhancing the specific T cell immune response against micro- and nanoparticle immobilized antigen

The current study was a part of the project on generating viral particle traps occurring due to covalent immobilization on the interface of recombinant virus-specific polymer-based nano- and microparticles. It is assumed that protein-particle conjugates could be able to bind virions followed by engulfment by immune cells. The study was aimed to examine the effect of polylactic acid (PLA) and PLA block-copolymer with polyethylene glycol (PLA-PEG)-based micro- and nanoparticles on the cellular immune response against polymeric particle-bound antigen. Materials and methods. A recombinant chimeric protein beta-2-microglobulin — green fluorescent protein (β2M-sfGFP) was obtained by affine chromatography. The recombinant protein was immobilized onto the polymer particles, which were further used for mice immunization. Female F1 hybrid mice (CBA x C57BL) in experimental and control groups consisted of 4–6-month-old 15 animals (weighted 20–25 g). Intracellular cytokine staining was used to evaluate the cellular immune response. Results and discussion. It was shown that the nanoparticles of PLA block-copolymer with polyethylene glycol (PLA-PEG) were able to bind 10 microgram protein per 1 mg polymer. The polylactic acid nanoparticles were able to bind 2,3 microgram protein per 1 mg polymer. In experiment, mice in group 1 were immunized with 100 nm PLA-PEG particle-β2M-sfGFP conjugate, in group 2 — with same particles together with soluble β2M-sfGFP. In group 3, mice were immunized with 1400 nm PLA particles-β2M-sfGFP conjugate, and in group 4 — with same particles together with soluble protein. The spleens isolated 2 weeks after the four-time intraperitoneal immunization. Comparison of immune response between groups was assessed by nonparametric Kruskal–Wallis criterion with Tukey correction. It was shown that the number of antigen-specific CD4+ T cells produced to model protein was significantly higher after immunization with particle-β2M-sfGFP conjugate, as compared to control groups, wherein immunization was performed with a mixture of protein and unmodified particles (p < 0.001). It was found that the number of antigen-specific CD8+ T cells formed against β2m-sfGFP did not differ between all groups examined

Enzyme-Mediated Ring-Opening Polymerization of Pentadecalactone to Obtain Biodegradable Polymer for Fabrication of Scaffolds for Bone Tissue Engineering

The optimization of enzyme-mediated polymerization of pentadecalactone (PDL) was performed to obtain macromolecular products suitable for generation of 3D cell supports (scaffolds) for bone tissue engineering. Such parameters as temperature, monomer/enzyme ratio, and monomer concentration were studied. The maximum molecular weight of synthesized polymers was about 90,000. Methods allowing the introduction of reactive double bonds into polypentadecalactone (polyPDL) structure were developed. The macroporous matrices were obtained by modification of thermoinduced phase separation method

Conformationally Constrained Peptides with High Affinity to the Vascular Endothelial Growth Factor

The design of efficient vascular endothelial growth factor (VEGF) inhibitors is a high-priority research area aimed at the treatment of pathological angiogenesis. Among other compounds, v114∗ has been identified as a potent VEGF-binding peptide. In order to improve the affinity to VEGF, we built a conformational constrain in its structure. To this aim, Cα-tetrasubstituted amino acid Aib was introduced into the N-terminal tail, peptide loop, or C-terminal helix. NMR studies confirmed the stabilization of the helical conformation in proximity to the Aib residue. We found that the induction of the N-terminal helical structure or stabilization of the C-terminal helix can noticeably increase the peptide affinity to the VEGF. These peptides efficiently inhibited VEGF-stimulated cell proliferation as well. The insertion of the non-proteinogenic Aib residue significantly enhanced the stability of the peptides in the vitreous environment. Thus, these Aib-containing peptides are promising candidates for the design of VEGF inhibitors with improved properties

Pyridazinone-substituted benzenesulfonamides display potent inhibition of membrane-bound human carbonic anhydrase IX and promising antiproliferative activity against cancer cell lines

An expanded set of pyridazine-containing benzene sulfonamides was investigated for inhibition of four human carbonic anhydrase isoforms, which revealed a pronounced inhibition trend toward hCA IX, a cancer-related, membrane-bound isoform of the enzyme. Comparison of antiproliferative effects of these compounds against cancer (PANC-1) and normal (ARPE-19) cells at 50 μM concentration narrowed the selection of compounds to the eight which displayed selective growth inhibition toward the cancer cells. More detailed investigation in concentration-dependent mode against normal (ARPE-19) and two cancer cell lines (PANC-1 and SK-MEL-2) identified two lead compounds one of which displayed a notable cytotoxicity toward pancreatic cancer cells while the other targeted the melanoma cells. These findings significantly expand the knowledge base concerning the hCA IX inhibitors whose inhibitory potency against a recombinant enzyme translates into selective anticancer activity under hypoxic conditions which are aimed to model the environment of a growing tumor