Inhalation exposure to nanosized and fine TiO2 particles inhibits features of allergic asthma in a murine model.
BACKGROUND
Nanotechnology and engineered nanomaterials (ENM) are here to stay. Recent evidence suggests that exposure to environmental particulate matter exacerbates symptoms of asthma. In the present study we investigated the modulatory effects of titanium dioxide particle exposure in an experimental allergic asthma.


METHODS
Nonallergic (healthy) and ovalbumin-sensitized (asthmatic) mice were exposed via inhalation to two different sizes of titanium dioxide particles, nanosized (nTiO2) and fine (fTiO2), for 2 hours a day, three days a week, for four weeks at a concentration of 10 mg/m3. Different endpoints were analysed to evaluate the immunological status of the mice.


RESULTS
Healthy mice elicited pulmonary neutrophilia accompanied by significantly increased chemokine CXCL5 expression when exposed to nTiO2. Surprisingly, allergic pulmonary inflammation was dramatically suppressed in asthmatic mice which were exposed to nTiO2 or fTiO2 particles - i.e. the levels of leucocytes, cytokines, chemokines and antibodies characteristic to allergic asthma were substantially decreased.


CONCLUSIONS
Our results suggest that repeated airway exposure to TiO2 particles modulates the airway inflammation depending on the immunological status of the exposed mice.
Unit of Excellence for Immunotoxicology, Finnish Institute of Occupational Health, Helsinki, Finland.
Elina M
EM
Rossi
Lea
L
Pylkkänen
Antti J
AJ
Koivisto
Heli
H
Nykäsenoja
Henrik
H
Wolff
Kai
K
Savolainen
Harri
H
Alenius
D000818:Animals; D001249:Asthma / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D019570:Inhalation Exposure; D007962:Leukocytes / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D053758:Nanoparticles; D010047:Ovalbumin; D052638:Particulate Matter / Q000008:administration & dosage / Q000494:pharmacology*; D011014:Pneumonia / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control; D014025:Titanium / Q000008:administration & dosage / Q000494:pharmacology*
D016207:Cytokines; D052638:Particulate Matter; C009495:titanium dioxide; D010047:Ovalbumin; D014025:Titanium