Correlation of CD66b+monocytes/polymorphonuclear Myeloid-derived Suppressor Cells (PMN-MDSC) Ratio and Their Effect on COVID‐19 Progression

Yöyen Ermiş D., Dombaz F., Etgü O., Karaçay M., Arslan G., Çağan E., ...More

5th International Molecular Immunology & Immunogenetics Congress, İzmir, Turkey, 20 - 22 October 2022, pp.9-10

  • Publication Type: Conference Paper / Summary Text
  • City: İzmir
  • Country: Turkey
  • Page Numbers: pp.9-10
  • Bursa Uludag University Affiliated: Yes


Introduction: CD66b+ monocytes first described in cancer and show proinflammatory characteristics. Although their common marker with PMN-MDSCs is CD66b,CD66b+ monocytes are distinguished phenotypically from these cells by their CD33orCD14 positivity. In this study, the effect of CD66b+ monocytes and PMN-MDSC interaction on disease prognosis in the pathogenesis of COVID-19 was evaluated for the first time in literature. Material-Methods: Leukocytes were obtained from 1.077g/mLficoll phase and whole blood of COVID‐19 positive children and adults(mild,moderate,severe disease).The surface molecules (CD45,CD11b,CD66b,CD15,CD14,CD33,CD14,CD16,HLA‐DR,CD114,CD62‐L,Lox‐1,PD‐L1,PD‐L2,CD80,CD86,CD25,CD154,CD69)were studied with flowcytometry.Dichlorodihydrofluorescein diacetate(DCFDA) and 4,5‐diaminofluoresceindiacetate(DAF‐2 DA) were used to measure ROS and NO production by myeloid cells,respectively.Carboxyfluorescein succinimidylester(CFSE) for proliferation analysis of CD4+ or CD8+T cells obtained from healthy donors in the presence of myeloid cells from COVID‐19 positive patients.Cytokines from co‐cultures were measured with LEGENDplex (IL‐4,IL‐2,CXCL10(IP‐10),IL‐1β,TNF‐α,CCL2(MCP‐1),IL‐17A,IL‐6 IL‐10,IFN‐γ,IL‐12p70,CXCL8 (IL‐8),TGF‐β1. Results and Discussion: High proportion of CD66b+ PMN-MDSC cells were observed in children diagnosed with COVID-19(0-13 years old),and CD66b+monocytes increased while PMN-MDSC decreased in acute phase of disease.Adult patients with severe disease can not modulate CD66b+ monocytes at the begining of infection.PMN-MDSCs increased very rapidly acute phase and were the most prominent sub-population in whole blood and 1.077 Ficoll phase from patients diagnosed severe disease. These results indicate that CD66b+ cells have two-sided effect on immune responses in COVID-19.Especially in acute phase of anti-viral immune responses,the presence of high levels of pro-inflammatory CD66b+ promote effective immune responses.

This study is being supported by The Scientific and Technological Research Council of Turkey (TUBITAK),Project no.120S653