Search

Simple Summary: HIV-1 is a hard-to-eradicate persisting infection which, despite the current antiretroviral therapy, takes about 600,000 human lives every year. HIV-1 uses the CD4 receptor and co-receptors CCR5 or CXCR4 on the surfaces of T cells, macrophages, and dendritic cells to enter the host immune cells. Inhibition of HIV-1 entry is one of the most effective approaches for blocking viral infection. Creating genetically engineered cells that are insensitive to HIV-1 entry is a promising instrument for virus eradication. We previously showed that knock-in-based expression of the fusion inhibitory peptides MT-C34 or 2P23 fully protected primary CD4 human T lymphocytes from HIV-1 infection. Here, we generated and characterized a novel human chimeric antibody against the MT-C34 peptide with the ability to mediate antibody-dependent cell cytotoxicity (ADCC). The created antibody is a useful supplementary reagent for the detection and enrichment of engineered HIV-1-resistant cells developed for research studies or clinical applications. Its ADCC activity can potentially be used for subsequent elimination of engineered malignancy-prone T and CAR cells in vivo, but the efficacy and limitations of in vivo antibody application should be determined further. Peptides from heptad repeat (HR1 and HR2) regions of gp41 are effective inhibitors of HIV-1 entry that block the fusion of viral and cellular membranes, but the generation of antibodies highly specific for these peptides is challenging. We have previously described a mouse hybridoma that recognizes MT-C34-related peptides derived from HR2. It was used for the selection of HIV-1-resistant CD4 lymphocytes engineered to express the MT-C34 peptide via a CRISPR/Cas9-mediated knock-in into the CXCR4 locus. In this study, we cloned variable domains of this antibody and generated a recombinant chimeric antibody (chAb) by combining it with the constant regions of the humanized antibody Trastuzumab. The new chAb displayed a high specificity and two-fold higher level of affinity than the parental mouse monoclonal antibody. In addition, chAb mediated up to 27–43% of the antibody-dependent cellular cytotoxicity towards cells expressing MT-C34 on their surface. The anti-MT-C34 chAb can be easily generated using plasmids available for the research community and can serve as a valuable tool for the detection, purification, and even subsequent elimination of HIV-1-resistant CD4 cells or CAR cells engineered to fight HIV-1 infection. [ABSTRACT FROM AUTHOR]

Endothelial cells in brain capillaries are crucial for the function of the blood–brain barrier (BBB), and members of the tight junction protein family of claudins are regarded to be primarily responsible for barrier properties. Thus, the analysis of bioactive substances that can affect the BBB's permeability is of great importance and may be useful for the development of new therapeutic strategies for brain pathologies. In our study, we tested the hypothesis that the application of the glucocorticoid prednisolone affects the murine blood–brain barrier in vivo. Isolated brain tissue of control and prednisolone-injected mice was examined by employing immunoblotting and confocal laser scanning immunofluorescence microscopy, and the physiological and behavioral effects were analyzed. The control tissue samples revealed the expression of barrier-forming tight junction proteins claudin-1, -3, and -5 and of the paracellular cation and water-channel-forming protein claudin-2. Prednisolone administration for 7 days at doses of 70 mg/kg caused physiological and behavioral effects and downregulated claudin-1 and -3 and the channel-forming claudin-2 without altering their localization in cerebral blood vessels. Changes in the expression of these claudins might have effects on the ionic and acid–base balance in brain tissue, suggesting the relevance of our findings for therapeutic options in disorders such as cerebral edema and psychiatric failure. [ABSTRACT FROM AUTHOR]

The influence of the nutrient medium hormonal composition on the induction of calluso- and morphogenesis in Lavandula angustifolia Mill., as well as the content of some endogenous hormones (indolylacetic acid, cytokinins, abscisic acid) in morphogenic and non-morphogenic calli, were studied. The leaf explants were isolated from obtained in vitro plants of the Stepnaya and Vdala cultivars. In primary calli with a frequency of 5.7-11.6%, buds and shoots were formed on different Murashige and Skoog (MS) culture media supplemented with 6-benzylaminopurine, thidiazuron, kinetin, and gibberellic acid. In the callus of the first passage in both cultivars, the induction of morphogenesis was observed with the greatest frequency (39.5-43.2%) on the MS medium with the addition of 1.0 mg/l 6-benzylaminopurine and 1.0 mg/l kinetin. Morphogenic calli of the Vdala cultivar were characterized by a higher content of cytokinins, but a lower content of indolylacetic and abscisic acids compared with non-morphogenic ones.

The use of in vitro callus cultures as experimental model systems allows us to get closer to understanding the patterns and features of morphogenesis in intact plants. In this regard, the problem of realizing the morphogenetic potential of callus cells due to their pluri- and totipotency properties is of great interest. To solve this problem, it is important to use the histological approach, which involves studying the structures of developing tissues, organs and organisms in their interactions and relationships. This review article analyzes data devoted to the study of the histological features of formed primary morphogenic calli (formation of morphogenetic centers and superficial meristematic zones), as well as the in vitro morphogenesis pathways in calli that lead to the formation of regenerants (de novo organogenesis and in vitro somatic embryogenesis). The terminology used is considered. Some questions for discussion are raised. The opinion is expressed that histological (structural) studies should be considered as a methodologic basis for further investigation of various morphogenetic scenarios in in vitro callus cultures, especially in economically valuable plants and for biotechnological purposes. [ABSTRACT FROM AUTHOR]

Objective: The morphology and functions of the proximal and distal large intestine are not the same. The incidence of colorectal cancer in these regions is also different, as tumors more often appear in the descending colon than in the ascending colon. Inflammatory bowel disease and colorectal cancer can increase transepithelial permeability, which is a sign of reduced intestinal barrier function. However, there is not enough evidence to establish a connection between the difference in colorectal cancer incidence in the proximal and distal colon and intestinal permeability or the effects of carcinogenesis on the barrier properties in various areas of the colon. The aim of the study was to assess the permeability of different segments of the large intestine according to a developed mapping methodology in healthy rats and rats with 1,2-dimethylhydrazine (DMH)-induced colon adenocarcinoma. Methods: The short circuit current, the transepithelial electrical resistance and the paracellular permeability to fluorescein of large intestine wall of male Wistar rats were examined in the Ussing chambers. The optical density of the solution from the serosa side to assess the concentration of the diffused fluorescein from mucosa to serosa was analyzed by spectrophotometry. The morphometric and histological studies were performed by optical microscopy. Results: Rats with DMH-induced colon adenocarcinomas showed elevated transepithelial electrical resistance in the areas of neoplasm development. In contrast, there was no change in the electrophysiological properties of tumor adjacent areas, however, the paracellular permeability of these areas to fluorescein was increased compared to the control rats and was characterized by sharply reduced barrier function. Conclusions: The barrier properties of the colon vary depending on tumor location. The tumors were less permeable than the intact intestinal wall and probably have a negative influence on tumor-adjacent tissues by disrupting their barrier function. [ABSTRACT FROM AUTHOR]

The periodization of wheat embryogenesis on the base of anatomy-morphological and temporal criterions has been proposed. The stages of non-differentiated embryo, embryo differentiation and differentiated embryo were described. [ABSTRACT FROM AUTHOR]

Identifying protein-protein interactions is crucial for revealing protein functions and characterizing cellular processes. Manipulating PPIs has become widespread in treating human diseases such as cancer, autoimmunity, and infections. It has been recently applied to the regulation of protein tyrosine phosphatases (PTPs) previously considered undruggable. A broad panel of methods is available for studying PPIs. To complement the existing toolkit, we developed a simple method called fluorescent immunoprecipitation analysis (FIPA). This method is based on coimmunoprecipitation followed by protein gel electrophoresis and fluorescent imaging to visualize components of a protein complex simultaneously on a gel. The FIPA allows the detection of proteins expressed under native conditions and is compatible with mass spectrometry identification of protein bands., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)