Human rhinovirus 1B exposure induces phosphatidylinositol 3-kinase-dependent airway inflammation in mice.
BACKGROUND
Infection with rhinovirus (RV) triggers exacerbations of asthma and chronic obstructive lung disease.


OBJECTIVE
We sought to develop a mouse model of RV employing RV1B, a minor group serotype that binds to the low-density lipoprotein receptor.


METHODS
C57BL/6 mice were inoculated intranasally with RV1B, replication-deficient ultraviolet (UV)-irradiated RV1B, or RV39, a major group virus.


RESULTS
Viral RNA was present in the lungs of RV1B-treated mice, but not in those exposed to UV-irradiated RV1B or RV39. Lung homogenates of RV-treated mice contained infectious RV 4 days after inoculation. RV1B exposure induced neutrophilic and lymphocytic airway inflammation, as well as increased lung expression of KC, macrophage-inflammatory protein-2, and IFN-alpha and IFN-beta. RV1B-exposed mice showed airway hyperresponsiveness 1 and 4 days after inoculation. UV-irradiated RV1B induced modest neutrophilic airway inflammation and hyperresponsiveness 1 day after exposure. Both RV1B and UV-irradiated RV1B, but not RV39, increased lung phosphorylation of Akt. Confocal immunofluorescence showed colocalization of RV1B and phospho-Akt in the airway epithelium. Finally, pretreatment with the phosphatidylinositol 3-kinase inhibitor LY294002 attenuated chemokine production and neutrophil infiltration.


CONCLUSIONS
We conclude that RV1B induces airway inflammation in vivo. Evidence is presented that viral replication occurs in vivo and is required for maximal responses. On the other hand, viral replication was not required for a subset of RV-induced responses, including neutrophilic inflammation, airway hyperresponsiveness, and Akt phosphorylation. Finally, phosphatidylinositol 3-kinase/Akt signaling is required for maximal RV1B-induced airway neutrophilic inflammation, likely via its essential role in virus internalization.
Newcomb
Dawn C
DC
Medical Sciences Research Building II, 1150 W. Medical Center Drive, Room 3570B, Ann Arbor, MI 48109-0688, USA.
Sajjan
Umadevi S
US
Nagarkar
Deepti R
DR
Wang
Qiong
Q
Nanua
Suparna
S
Zhou
Ying
Y
McHenry
Christina L
CL
Hennrick
Kenneth T
KT
Tsai
Wan C
WC
Bentley
J Kelley
JK
Lukacs
Nicholas W
NW
Johnston
Sebastian L
SL
Hershenson
Marc B
MB
D000818:Animals; D001249:Asthma / Q000150:complications / Q000821:virology; D016535:Bronchial Hyperreactivity / Q000276:immunology / Q000821:virology; D018925:Chemokines / Q000378:metabolism; D002633:Chemotaxis; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000276:immunology / Q000821:virology; D005260:Female; D006801:Humans; D051379:Mice; D009504:Neutrophils / Q000276:immunology; D051058:Oncogene Protein v-akt / Q000276:immunology / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010850:Picornaviridae Infections / Q000276:immunology* / Q000503:physiopathology; D011014:Pneumonia / Q000276:immunology / Q000821:virology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000821:virology; D012229:Rhinovirus / Q000472:pathogenicity*; D015398:Signal Transduction
D018925:Chemokines; D019869:Phosphatidylinositol 3-Kinases; D051058:Oncogene Protein v-akt