Influence of B7 costimulatory molecules colocalized in extracellular traps (ETs) on CD45RO expression in human autologous cultures
Extracellular traps (ETs) are structures composed of chromatin, histones and granular proteins, and constitute a functional microbicidal mechanism of immune cells. Its participation in the pathophysiology of many pathologies, including COVID-19, autoimmune diseases and cancer, has been studied. Cost...
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| Autores principales: | , , , , , , |
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| Formato: | Artículo revista |
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Universidad Nacional Córdoba. Facultad de Ciencias Médicas. Secretaria de Ciencia y Tecnología
2022
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| Acceso en línea: | https://revistas.unc.edu.ar/index.php/med/article/view/39025 |
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| Sumario: | Extracellular traps (ETs) are structures composed of chromatin, histones and granular proteins, and constitute a functional microbicidal mechanism of immune cells. Its participation in the pathophysiology of many pathologies, including COVID-19, autoimmune diseases and cancer, has been studied. Costimulatory molecules B7 (B7-1:CD80 and B7-2:CD86) provide the second activation signal for T cells, and their absence is a mechanism of peripheral tolerance. The objectives were to study the influence of B7 molecules colocalized in ETs generated in vitro from leukocytes, on the expression of common leukocyte antigen CD45RO in autologous human blood cell cultures. This molecule is an indicator of T cell activation, and its expression in neutrophils is related to adhesion and activation.
For that reason, we set out to generate and isolate ETs in autologous cultures of leukocytes exposed to lipopolysaccharide (LPS); to mark B7 molecules in isolated ETs and observe the expression of the CD4 coreceptor and CD45RO in interaction assays of ETs and autologous leukocytes in culture. Autologous leukocyte cultures were performed from healthy human blood samples anticoagulated with heparin, (n = 10) (with informed consent, Ethics Committee, HNC, FCM), stimulated with LPS for generation of ETs. We performed: isolation of ETs and ETs interaction assays with autologous cultures. Immunofluorescence (IF) with anti-CD80, anti-CD86, anti-CD4 and anti-CD45RO, DNA staining with DAPI. Controls: paired culture samples. Quantification of labeled cells was performed with FIJI program. Statistical treatment: t-test for paired samples.
At 24 hours of culture, no significant differences (p<0.05) were observed in the percentages of positive cells for CD4 and CD45RO between the paired control samples and those with added ETs. At 72 hours, significant differences (p<0.05) were observed in the expression of CD45RO between the controls and the samples with added ETs. In one donor, significant differences (p<0.05) were observed in the percentages of CD4-positive cells.
The presence of B7 molecules in ETs could give the second signal required for the activation of autoreactive T lymphocytes present in the autologous culture of total leukocytes, implying the possibility of breaking self-tolerance. |
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