Phenotypes and functions of low(er)‐density neutrophils (LDNs) in early childhood and children

Dombaz F., Karaçay M., Etgü O., Kızmaz M. A., Şimşek A., Çağan E., ...More

6th European Congress of Immunology, İstanbul, Turkey, 1 - 04 September 2021, pp.185

  • Publication Type: Conference Paper / Summary Text
  • City: İstanbul
  • Country: Turkey
  • Page Numbers: pp.185
  • Bursa Uludag University Affiliated: Yes


Young infants respond relatively poorly to many infections and vaccines, but the basis of reduced immunity in infants is not completely defined. Mature neutrophils and granulocyticmyeloid

derived suppressor cells (G‐MDSC) can express similar cell surface markers. However, G‐MDSCs are functionally distinguished from neutrophils by its immunosuppressive

capacity on T cell responses. The literature regards G‐MDSCs as low density cells and indicate that they accumulate to upper 1.077g/mL Ficoll fraction. In this study, we aimed to

investigate low and high density of neutrophils that were accumulated both upper and lower phase of 1.077g/mL Ficoll phase Leukocytes were obtained from upper or lower 1.077g/

mL ficoll phase of children (age range from 5 days to 15 years).High and low density neutrophils were positively selected using with CD66b microbeads by magnetic activated cell

sorting.Different CD66b surface expression levels were detected (dim, mod and high) and purified by floresen activating cell sorting (FACS).These subpopulations surface molecules

expression (CD15,CD14,CD33,CD16,HLA‐DR,CD114,CD62‐L,Lox‐1,PD‐L1,PD‐L2,CD80,CD86) were studied with flow cytometry.Dichlorodihydrofluorescein diacetate(DCFDA) was used

to measure ROS production.Carboxyfluorescein succinimidyl ester(CFSE) for proliferation analysis of CD4+ or CD8+ T cells obtained from healthy donors in the presence of low or

high density of neutrophils from healthy children.Haematoxylin‐eosin staining of blood smears were used for confirm maturation stages of neutrophils. Peripheral blood low‐density

neutrophils in early childhood stimulate T‐cell responses as much as high‐density neutrophils

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