Maryna Skok
Palladin Institute of Biochemistry, Ukraine
Title: Immune reaction to fragment 674-685 of SARS-Cov-2 spike protein results in neuroinflammation in the brain and impairs memory
Biography
Biography: Maryna Skok
Abstract
COVID-19 caused by SARS-Cov-2 infection affects multiple organs and tissues including the brain. Post-COVID patients often suffer from cognitive disorders like depression, intellectual weakness and memory loss. The fragment 674-685 of SARS-Cov-2 spike protein is homologous to the fragment 27-37 of α-cobratoxin underlying its interaction with α7 nicotinic acetylcholine receptors (nAChRs) known to be involved in memory and cognition. The biochemical studies demonstrated direct interaction of 674-685 spike protein fragments with the portion 179-190 of α7 nAChR. We immunized mice with 674-685 peptide coupled to a protein carrier and observed an impairment of episodic memory measured in novel object recognition test starting from day 14 after initial immunization and further progressing after the second immunization that coincided with the peaks of (674-685)-specific antibodies in the blood. The antibodies of such specificity were also found in the brain of mice sacrificed on day 14 after the second immunization. The antibody presence was accompanied with the decrease of α7 nAChRs and increased levels of pro-inflammatory cytokines IL-1β and TNFα in the brain. Choline prevented (674-685)-specific antibody binding to BSA-coupled (674-685) peptide indicating that the antibody could bind choline. When injected regularly in (674-685)-immunized mice choline prevented memory loss and the decrease of α7 nAChRs in the brain. Finally, immunoglobulins of (674-685)-immunized mice, passively transferred to non-immunized mice, decreased their episodic memory within two days. The mechanisms of such effect, as well as its relevance to COVID-19 will be discussed.