Evaluation of potential protein ligands for RSV on the neutrophil extracellular traps

• Grant number: 21/05107-4
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): August 01, 2021
• Effective date (End): July 31, 2022
• Field of knowledge: Biological Sciences - Immunology - Cellular Immunology
• Principal researcher: Karina Alves de Toledo
• Grantee: Leonardo da Silva Pinto
• Home Institution: Faculdade de Ciências e Letras (FCL-ASSIS). Universidade Estadual Paulista (UNESP). Campus de Assis. Assis , SP, Brazil

Abstract

Respiratory Syncytial Virus (hRSV) is the main etiologic agent of acute viral infections of the lower respiratory tract, against which no specific treatment or vaccine has yet been approved. In the lung tissue of the infected patient, there is an intense accumulation of neutrophils. In the sustained presence of external stimuli (microorganisms, parasites, and inflammatory mediators), activated neutrophils secrete their nuclear content, carrying with them cytoplasmic and granular material. The extracellular structure generated is called "Neutrophil Extracellular Traps" or NETs, which have microbicidal functions, capturing and/or inactivating bacteria, viruses, fungi, and parasites. Recent studies demonstrate that hRSV is able to induce the formation of NETs through its protein F. The excess of NETs, cellular debris, and mucus resulting from hRSV infection form a consistent mucus that is difficult to expectorate that accumulates in the lumen of the bronchioles, drastically restricting the flow of air, aggravating the patient's clinical condition. NETs have been shown to interact with hRSV viral particles and recent data from our group indicates that this contact results in virucidal action of these structures. Currently, through the approved Regular FAPESP Project (process number 2018 / 09021-4), our group is interested in investigating the interaction of NETs with hRSV, and detailing the consequences of these interactions in the course of viral infection. The present project is part of this context, by proposing a scientific initiation study that aims to evaluate possible ligands of the RSV virus in the structure of NETs. For that, immunoblotting assays will be carried out, incubating samples of the virus with nitrocellulose membranes containing NETs impregnated after electrophoresis. In a second step, immunoprecipitated samples after incubation of NETs with RSV will be submitted to electrophoresis. In both cases, the assays will be aided by the use of the Palivizumab antibody, specific for viral F protein. The data generated in this study, in addition to those obtained in the approved regular project, may direct new strategies in the treatment of patients with hRSV, from improving respiratory quality to blocking viral dissemination. (AU)