Fig. 2

Chronic inhalatory exposure to aerosols emitted from alternative tobacco products modulates lung innate immune-cell accumulation. Total numbers of leukocytes (A), CD11b⁺Ly6G⁺ neutrophils (B), CD11b⁺ CD68⁺ macrophages in the lungs of mice exposed to air, EC, HTP or CC were determined by multicolor flow cytometry using specific antibody markers. Staining protocol and gating strategy are described previously [47] and depicted in Additional file 1: Fig. S1 and with details in online Additional file 1. Data are shown as bar diagrams with mean ± SE. Non-parametric Kruskal–Wallis test with FDR correction for multiple comparison was performed to see if statistically significant differences exist between two groups using GraphPad Prism V.9 software (GraphPad; La Jolla, California, USA). Difference between two groups is considered significant at p < 0.05 and are indicated with symbols **p < 0.01; ***p < 0.001; ****p < 0.0001 using a post-test comparison with Tukey’s correction. In each exposure condition, n = 10 for air (5M + 5F) and n = 20 for EC, HTP, and CC (10M + 10F) per group were used