Aspergillus fumigatus conidia upregulates NOD2 protein expression both in vitro and in vivo.
OBJECTIVE
To determine if NOD2 is involved in host recognition of Aspergillus fumigatus (Af) conidia.


METHODS
An Af conidia pulmonary infection murine model was established by intranasal inoculation of Af conidia suspensions. Protein levels of NOD2 in lung tissue were determined by immunohistochemistry. A549 and phorbol-12-myristate 13-acetate (PMA)-activated THP-1 cell lines were treated with heat-killed Af conidia, then the presence of NOD2 protein in these cell lines was detected by Western blotting. The ability of muramyl dipeptide (MDP) to induce the secretion of TNF-alpha after incubation with heatkilled Af conidia was measured by enzyme-linked immunosorbent assay.


RESULTS
The expression of NOD2 protein in lung tissue increased after Af conidia infection. Heat-killed Af conidia significantly upregulated NOD2 protein expression in A549 cells and PMA-activated THP-1 cells. Additionally, Af conidia in conjuction with MDP, significantly increased the secretion of TNF-alpha in A549 cells and PMA-activated THP-1 cells.


CONCLUSIONS
Af conidia upregulates NOD2 protein expression in vitro and in vivo. These findings indicate that NOD2 protein may respond to Af conidia.
Zhang
Hui-jun
HJ
Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
Qu
Jie-ming
JM
Shao
Chang-zhou
CZ
Zhang
Jing
J
He
Li-xian
LX
Yuan
Zheng-hong
ZH
D000818:Animals; D001232:Aspergillus fumigatus / Q000378:metabolism / Q000502:physiology*; D002460:Cell Line; D006801:Humans; D008168:Lung / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D053473:Nod2 Signaling Adaptor Protein / Q000096:biosynthesis* / Q000235:genetics; D010587:Phagocytosis / Q000187:drug effects; D013172:Spores, Fungal / Q000737:chemistry*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein; D014409:Tumor Necrosis Factor-alpha