Biology subjects

Lodygin, D.

Publications and source records attributed to Lodygin, D..

2 recordsLinked to original sources

bioRxiv2026

Ryanodine receptor 1 is dispensable for CD4+ T-cell differentiation and effector function in intestinal inflammation models

T-cell receptor signaling is necessary for the activation and differentiation of CD4 T cells. Calcium (Ca2+) signaling is essential for this process, and the complexity of Ca2+ channels presents a potential therapeutic target for modulating the strength of T-cell receptor signaling and further differentiation of CD4 T cells. Nicotinic acid adenine dinucleotide phosphate (NAADP) is a potent Ca2+-mobilizing second messenger that triggers Ca2+ release through ryanodine receptor 1 (RYR1) in T cells. While the molecular and biophysical properties of NAADP-induced Ca2+ microdomains in T cells have been thoroughly investigated, and the function of the NAADP-HN1L/JPT2-RYR1 axis has been proven in T-cell activation and proliferation, its role in intestinal inflammation in vivo remains to be elucidated. In this study, we generated a conditional knockout mouse with Ryr1 deleted in {beta} T cells to investigate the functional relevance of RYR1 signaling in CD4 T cells. Ryr1 deletion in CD4+ T cells decreased TCR-induced Ca2+ microdomain formation, reduced peak Ca2+ amplitude and delayed initial velocity of global Ca2+ signaling in vitro. However, Ryr1 expression in CD4 T cells was dispensable for their pathogenicity in murine models of intestinal inflammation. Thus, Ryr1 expression in CD4+ T cells plays a redundant role in intestinal inflammation.

immunology↗

bioRxiv2024

Nanobodies against the myelin enzyme CNPase as tools for structural and functional studies

2,3-cyclic nucleotide 3-phosphodiesterase (CNPase) is an abundant constituent of central nervous system non-compact myelin, frequently used as a marker antigen for myelinating cells. The catalytic activity of CNPase, the 3-hydrolysis of 2,3-cyclic nucleotides, is well characterised in vitro, but the in vivo function of CNPase remains unclear. CNPase interacts with the actin cytoskeleton to counteract the developmental closure of cytoplasmic channels that travel through compact myelin; its enzymatic activity may be involved in adenosine metabolism and RNA degradation. We developed a set of high-affinity nanobodies recognizing the phosphodiesterase domain of CNPase, and the crystal structures of each complex show that the five nanobodies have distinct epitopes. One of the nanobodies bound deep into the CNPase active site and acted as an inhibitor. Moreover, the nanobodies were characterised in imaging applications and as intrabodies, expressed in mammalian cells, such as primary oligodendrocytes. Fluorescently labelled nanobodies functioned in imaging of teased nerve fibers and whole brain tissue sections, as well as super-resolution microscopy. These anti-CNPase nanobodies provide new tools for structural and functional biology of myelination, including high-resolution imaging of nerve tissue.

biochemistry↗