ANALYSIS OF P16, NKG2D AND MICA/B EXPRESSION IN PULMONARY INJURY OF PATIENTS WITH LETHAL COVID-19
Name: PAOLA DE OLIVEIRA LOPES
Publication date: 12/08/2022
Advisor:
Name |
Role |
|---|---|
| DANIEL CLAUDIO DE OLIVEIRA GOMES | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| DANIEL CLAUDIO DE OLIVEIRA GOMES | Advisor * |
| FAUSTO EDMUNDO LIMA PEREIRA | Internal Examiner * |
Summary: Patients who develop more severe symptoms of COVID-19 often present an acute inflammatory lung injury. Senescent cells accumulate in tissues during ageing, chronic stimulatory processes and infections. These cells present phenotypic and functional disorders, resulting in the inability to control pathogens, as well as tissue pathogenesis mediated through intense inflammatory activity. The latter favours the acquisition of natural killer cell receptors (NKRs) on CD8 T cells, and their ligands (NKRL) and other
cell populations. In this work, using immunohistochemistry and immunofluorescence techniques we demonstrate that patients display an intense cellular infiltrate with an accumulation of senescent CD8 T cells and alveolar macrophages (CD68+). Complementary analyzes in patients` lungs demonstrate the presence of cells expressing the MICA/B ligand, which was significantly more associated with macrophages. Interesting, no differential expression was seen in lung epithelial cells (AE1AE3). The presence of cells expressing the NK cell receptor (NKG2D) was determined in the lung lesion, however, compared to healthy controls, we did not find its expression associated with infiltrating CD8 T lymphocytes. This suggests that possible damage mediated by nonspecific antigen activation of CD8 T cells may be
mediated by other NK cell ligands. The results of this work contribute to a better understanding of the participation of senescence and the activity of NKRs expressed by senescent T cells in the immunopathogenesis of COVID-19.
