[Neutrophils induce the maturation and activation of immature dendritic cells during adaptive immune responses].
OBJECTIVE
To investigate whether polymorphonuclear neutrophilic leucocyte (PMN) can induce the maturation and activation of immature dendritic cells, thus promoting the Th1 immunity to microbial pathogens in vitro.


METHODS
PMN isolated from mouse bone marrow were stimulated by lipopolysaccharide (LPS), and were cultured with immature DC (imDCs) isolated from mouse bone marrow for 18 hours. Then the analysis of DC surface markers CD40 and CD86 was done by flow cytometry, and ELISA was used to detect the levels of TNF-alpha and IL-12. Purified DC cocultured with LPS-PMN (PMN-DC) and imDC were incubated with fluorescein isothiocyanate conjugated OVA (FITC-OVA), and the phagocytic capacity of PMN-DC and imDC was assessed by flow cytometry. Splenic CD4(+) T cells from DO11.10 x C57BL/6 F1 hybrid mice were obtained, and then cultured with PMN-DC or imDC in the presence of OVA (323 - 339). The cells were double stained with anti-CD4-PE and 7-amino-actinomycin D. The cellular data were acquired for 56s with a flow cytometer and the assay of IFN-gamma and IL-4 was done by intracellular staining.


RESULTS
LPS-PMN induced strong up-regulation of CD40 and CD86, and this capacity was remarkably inhibited after being neutralized by anti-TNF-alpha monoclonal antibody. LPS-PMN also stimulated imDCs to produce IL-12 and TNF-alpha. PMN-DCs demonstrated decreased phagocytic capacity compared with that of imDCs. Furthermore, the PMN-DC induced considerable DO11.10 T cell proliferation, and stimulated DO11.10 T cell to produce a large amount of IFN-gamma, but a relatively low amount of IL-4.


CONCLUSIONS
LPS-PMN can induce the maturation and activation of imDCs, including the cytokine secretion, specific antigen presentation and Th1 differentiation, thus promoting the type I immunity to microbial pathogens.
Wan
Xiao-xiao
XX
Department of Urology, Jinshan Hospital, Fudan University, Shanghai 200540, China.
Zheng
Ping
P
Chen
Gang
G
D000818:Animals; D051940:B7-2 Antigen / Q000276:immunology; D001854:Bone Marrow Cells / Q000166:cytology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D019013:CD40 Antigens / Q000276:immunology; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology*; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D015847:Interleukin-4 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D009504:Neutrophils / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D051940:B7-2 Antigen; D019013:CD40 Antigens; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4