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Generation of Human Monocyte-derived Dendritic Cells from Whole Blood
Published on: December 24, 2016
Deoxynucleic acids from Cryptococcus neoformans activate myeloid dendritic cells via a TLR9-dependent pathway
Kiwamu Nakamura1, Akiko Miyazato, Gang Xiao
1Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
Cryptococcal DNA activates immune cells called myeloid dendritic cells (BM-DCs) through Toll-like receptor 9 (TLR9). This interaction suggests a role for CpG DNA in the inflammatory response to fungal infections.
Area of Science:
- Immunology
- Mycology
- Infectious Diseases
Background:
- The recognition mechanisms of *Cryptococcus neoformans* by host cells are not fully understood.
- This fungus is an opportunistic pathogen affecting immunocompromised individuals.
Purpose of the Study:
- To investigate if *Cryptococcus neoformans* DNA activates mouse myeloid dendritic cells (BM-DCs).
- To elucidate the role of Toll-like receptor 9 (TLR9) in this activation process.
Main Methods:
- Stimulation of BM-DCs with *C. neoformans* DNA and assessment of cytokine release (IL-12p40) and surface marker expression (CD40).
- Experiments using DNase, RNase, chloroquine, bafilomycin A, and inhibitory oligodeoxynucleotides (ODN).
- Studies with gene-disrupted mice (TLR9(-/-), MyD88(-/-)), methylase-treated DNA, luciferase reporter assays, and confocal microscopy.
Main Results:
- *C. neoformans* DNA induced IL-12p40 release and CD40 expression in BM-DCs, dependent on TLR9 and MyD88.
- TLR9(-/-) mice showed increased susceptibility to pulmonary *C. neoformans* infection.
- Methylation of cryptococcal DNA reduced IL-12p40 synthesis, and cryptococcal DNA activated NF-κB via TLR9.
Conclusions:
- *Cryptococcus neoformans* DNA activates BM-DCs in a TLR9-dependent manner.
- CpG motif-containing DNA from *C. neoformans* likely contributes to inflammatory responses during infection.
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