Tag Archives: neutrophil extracellular traps

NET-inducing diamond nanoparticles with adsorbed hydrophobic SARS-CoV-2 antigens serving as vaccine candidate

G. Bila, V. Vovk, V. Utka, R. Grytsko, A. Havrylyuk, V. Chopyak, R. Bilyy*

Danylo Halytsky Lviv National Medical University, Lviv, Ukraine;
*e-mail: r.bilyy@gmail.com

Received: 14 April 2024; Revised: 17 May 2024;
Accepted: 25 July 2024; Available on-line: 04 September 2024

This study addresses the current need for vaccine adjuvants able to induce an immune response to novel or mutated pathogens. It exploits the ability of nanodiamonds (ND) to induce the formation of neutrophil extracellular traps (NETs) triggering inflammation, accompanied by immune response to co-injected antigens. Hydrophobic nanodiamonds 10 nm in diameter were covered with 194 a.a. sequence of the receptor-binding domain of Spike protein of SARS-CoV-2 via passive adsorption. It was shown that antigen-covered ND induce activation of human neutrophils and stimulate NETs formation and ROS production. When used for immunization antigen-covered ND induced long-lasting immune response in mice with prevailing IgG1 among antibody subclasses. The injected nanoparticles were sequestered by NETs and safely covered with connective tissues when examined 1 year after injection.

Neutrophil activation at high-fat high-cholesterol and high-fructose diets induces low-grade inflammation in mice

G. Bila1, O. Vishchur2, V. Vovk3, S. Vari4, R. Bilyy1*

1Department of Histology, Cytology and Embryology,
Danylo Halytsky Lviv National Medical University, Lviv, Ukraine;
2Institute of Animal Biology NAAS, Lviv, Ukraine;
3Department of Pathological Anatomy and Forensic Medicine,
Danylo Halytsky Lviv National Medical University, Lviv, Ukraine;
4International Research and Innovation in Medicine Program,
Cedars-Sinai Medical Center, Los Angeles, California, USA;
*e-mail: r.bilyy@gmail.com

Received: 05 February 2024; Revised: 17 March 2024;
Accepted: 17 March 2024; Available on-line: 30 April 2024

Nonalcoholic fatty liver disease (NAFLD), which can progress to nonalcoholic steatohepatitis (NASH), is a significant health concern affecting a substantial portion of the population. This study investigates the role of neutrophil extracellular traps (NETs) in liver inflammation induced by high-fat high-cholesterol diet (HFHCD) and high-fructose diet (HFD). The chronic nature of NAFLD involves low-grade inflammation with cytokine elevation. The research aims to visualize neutrophil elastase (NE) activity during HFHCD and HFD representing conditions of low-grade activation and assess neutrophil functional status. The study employs a mouse model subjecting animals to HFHCD, HFD or a standard diet (SD) for six weeks. Various analyses were used including histological evaluations, in vivo imaging of NE activity using a fluorescent probe, fluorescent microscopy, flow cytometry and assessment of neutrophil function through reactive oxygen species (ROS) levels. Mice on HFHCD and HFD display liver damage consistent with NASH, which was validated pathohistologically. NE activity in blood significantly increases after six weeks indicating systemic NETs involvement. In vivo imaging confirms NE activity in multiple organs. Cellular localization reveals NETs persistence even after neutrophil destruction in splenocytes indicating systemic involvement. Neutrophils under HFHCD exhibit a functional phenotype associated with low-grade inflammation, higher basal ROS levels and reduced activation potential. This study establishes the systemic impact of NETs in HFHCD- and HFD-induced liver inflammation, providing insights into the functional state of neutrophils. The findings contribute to understanding the mechanisms underlying chronic liver conditions and may inform future therapeutic strategies.