GM-CSF–licensed CD11b+ lung dendritic cells orchestrate Th2 immunity to Blomia tropicalis

Q Zhou, AWS Ho, A Schlitzer, Y Tang… - The Journal of …, 2014 - journals.aai.org
Q Zhou, AWS Ho, A Schlitzer, Y Tang, KHS Wong, FHS Wong, YL Chua, V Angeli
The Journal of Immunology, 2014journals.aai.org
The Blomia tropicalis dust mite is prevalent in tropical and subtropical regions of the world.
Although it is a leading cause of asthma, little is known how it induces allergy. Using a novel
murine asthma model induced by intranasal exposure to B. tropicalis, we observed that a
single intranasal sensitization to B. tropicalis extract induces strong Th2 priming in the lung
draining lymph node. Resident CD11b+ dendritic cells (DCs) preferentially transport Ag from
the lung to the draining lymph node and are crucial for the initiation of Th2 CD4+ T cell …
Abstract
The Blomia tropicalis dust mite is prevalent in tropical and subtropical regions of the world. Although it is a leading cause of asthma, little is known how it induces allergy. Using a novel murine asthma model induced by intranasal exposure to B. tropicalis, we observed that a single intranasal sensitization to B. tropicalis extract induces strong Th2 priming in the lung draining lymph node. Resident CD11b+ dendritic cells (DCs) preferentially transport Ag from the lung to the draining lymph node and are crucial for the initiation of Th2 CD4+ T cell responses. As a consequence, mice selectively deficient in CD11b+ DCs exhibited attenuated Th2 responses and more importantly did not develop any allergic inflammation. Conversely, mice deficient in CD103+ DCs and CCR2-dependent monocyte-derived DCs exhibited similar allergic inflammation compared with their wild-type counterparts. We also show that CD11b+ DCs constitutively express higher levels of GM-CSF receptor compared with CD103+ DCs and are thus selectively licensed by lung epithelial-derived GM-CSF to induce Th2 immunity. Taken together, our study identifies GM-CSF–licensed CD11b+ lung DCs as a key component for induction of Th2 responses and represents a potential target for therapeutic intervention in allergy.
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