Institute of
bioorganic chemistry

The diverse repertoire of T-cells plays a key role in the adaptive immune response. Researchers from the Laboratory of Comparative and Functional Genomics in collaboration with IKMB (Kiel, Germany) and ENS (Paris, France) used high throughput sequencing of alpha/beta T-cell receptors (TCR) as well as single cell RNA sequencing to analyse the alterations in T-cell repertoire after primary and secondary vaccination against yellow fever. The response to the secondary vaccination is an order of magnitude weaker, but much faster than the primary one. More than 60% of all cytotoxic response could be focused on a single epitope of the yellow fever virus. Researchers characterized distinctive motifs in amino acid TCR sequences that are essential for the recognition of this immunodominant epitope. The study is published in eLife.

Scientists from IMB, the University of Eastern Finland, together with employees of the Laboratory of molecular design and synthesis of IBCh RAS, study the cellular functions of biogenic polyamines spermin and spermidin involved in the regulation of vital cellular functions including proliferation and differentiation. An original system of C-methylated spermin derivatives was created, whose interaction with polyamine metabolism enzymes can be regulated by moving the methyl group along the spermin backbone. The use of these compounds allows us to study the individual cellular effects of easily interconvertible and partially interchangeable spermin and spermidin, as well as the mechanisms of Antizyme (OAZ1)-mediated downregulation of polyamines - the main mechanism for maintaining polyamine homeostasis in the cell. The work was published in Journal of Medicinal Chemistry.

Human biosynthetic machinery only synthesizes N-acetylneuraminic acid (Neu5Ac), while the other mammals synthesize both it and N-glycolylneuraminic acid (Neu5Gc), i.e., the latter is a potential xeno-antigen for humans. At the same time, Neu5Ac from the eaten meat of animals is metabolically active and found in human glycans, so it was believed that humans have antibodies to Neu5Gca2-3Galb1-4GlcNAc. Researchers from the Laboratory of Carbohydrates IBCH RAS systematically studied the repertoire of antibodies from healthy donors and found (see Glycobiology) that they have practically no antibodies to this glycan. At the same time, antibodies to Neu5Gc-containing glycans were found in patients with multiple sclerosis (see Neurology: Neuroimmunology & Neuroinflammation), which may be a marker of this disease.

Researchers from the Laboratory of Biophotonics and the Group of molecular tags for optical nanoscopy,  IBCH RAS, together with foreign colleagues developed a novel method of fluorescent labeling of proteins in living cells using short α-helices (so-called K/E-coils), which tend to interact with each other. The small size of the labels (only 2-3 kDa) should decrease the impact on the native dynamics of studied proteins. In comparison to popular covalent labels, K/E-coils can increase the resistance of labeling to photobleaching by an order of magnitude due to the continuous exchange of probes. In addition, this method makes it possible to observe the target proteins almost immediately after their synthesis without the need to wait for the long-term maturation of fluorescent proteins. This work was supported by the RSF grant 16-14-10364. Results are published in Cellular and Molecular Life Sciences.

Researchers from the Laboratory of Bioinformatics Approaches in Combinatorial Chemistry and Biology IBCH RAS, in collaboration with Irish colleagues, recently published a review in WIRES RNA that compiles the computational approaches, software tools, and data resources that have been developed over the last ten years for ribosome profiling data processing and analysis. The review outlines all the necessary steps involved in the initial processing of the data and highlights potential sources of artifacts and explains how to avoid them. Researchers can use this comprehensive guide to choose the most suitable tool depending on their specific goals and a preferable computational platform. Learn more