[Pollution and allergy: the contributions of animal and in vitro experimentation]

The respiratory pathological symptoms induced by atmospheric pollutants are closely dependent on the action of the aerocontaminants on the cells of the respiratory tract that are exposed to their effects. Two methods of experimental investigation are used to specify the effects of pollutants on the respiratory system: Study of the morphological and functional alterations of animal respiratory systems after exposure to different pollution constituents. Exposure of bronchitic or pulmonary cells to microquantities of pollutants, using different techniques that create direct contact between the pollutant and target cells. In animals gaseous pollutants alter the means of defence (muco-ciliary purification and antibacterial defence), inducing development of a neutrophil inflammatory reaction and, for ozone and NO2 favouring sensitisation by allergen-dependent IgE; diesel particles are responsible for restrictive ventilation problems, an inflammatory reaction, a sensitisation develops to pneumoallergens and in some cases of the development of pulmonary tumours. In vitro studies specify the cellular mechanisms and the molecules that are responsible for the observed phenomena: increase in the synthesis and expression of messenger DNA the codes for the pro-inflammatory cytokines, adherance molecules and chimiokines.