Influence of B7 costimulatory molecules colocalized in Extracellular Traps (ETs) on the expression of CD45RO in neutrophils and CD4 lymphocytes in human autologous cultures

Abstract

Extracellular traps (ETs) are structures composed of chromatin, histones and granular proteins, which constitute a functional microbicidal mechanism of immune cells. Currently, its participation in the pathophysiology of various pathologies, including COVID-19, autoimmune diseases and cancer, has been studied. Costimulatory B7 molecules (B7-1:CD80 and B7-2:CD86) provided the second activation signal for T cells. In this research, the study of the influence of colocalized B7 molecules in ETs was carried out in vitro from leukocytes on T-cell activation and CD45 RO expression in neutrophils in autologous human blood cell cultures. Objectives: to generate and isolate ETs in autologous cultures of leukocytes exposed to lipopolysaccharide (LPS); labelling B7 molecules in isolated ETs, CD4 co-receptor expression and CD45RO activation marker in interaction assays with ETs and autologous leukocytes in culture. Methods: autologous leukocytes cultures from healthy human blood samples anticoagulated with heparin, (n = 10) with informed consent (Ethics Committee, HNC, FCM), were stimulated with 25 ng/ml of LPS, 30 minutes. Subsequent isolation technique. Immunofluorescence technique with anti-CD80, anti-CD86, anti- CD4 and anti-CD45RO was performed, DNA staining: DAPI. Controls: paired blood samples. Statistical treatment: t-test for paired samples. Results: At 24 hours of culture, no significant differences (p