Table 2.

Chronic tobacco smoke exposure.

Treatment	Time	Response	Reference
Four cigarettes a day, 5 days a week	6 months	Both Th1 and Th17 cells are significantly increased, and the levels of IL-6 and IL-17 are also increased.	[30]
Twelve cigarettes a day, 5 days a week	6 months	An increase in the total number of inflammatory cells and macrophages in BALF of mice exposed to cigarette smoke. The release of IL-1β and TNF-α is increased as well.	[31]
Four times a day, 5 minutes per section, 5 days a week	4 months	Functional IL-17A protein secreted in the lung likely establishes an autocrine loop that further induces TH17 differentiation, thereby exacerbating the effect of smoke-induced TH1 and TH17 inflammation in the lungs.	[32]