Fig. 3

Chronic exposure to alternative tobacco product-aerosols induces adaptive and proinflammatory immune-cell accumulation in the lungs. Total numbers of CD19⁺ B cells (A), CD8⁺ T cells (B), CD4⁺ T cells (C) and CD4⁺IL17A⁺ inflammatory T cells in the lungs of mice exposed to air, EC, HTP or CC were calculated using multicolor flow cytometry after staining with specific antibody markers. Gating strategy was similar to that described previously [47] and depicted in Additional file 1: Fig. S1. Data are given 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 < 0.05, **p < 0.01; ***p < 0.001; ****p < 0.0001 using a post-test comparison with Tukey’s correction. In each exposure condition, we used n = 10 animals for air (5M + 5F) and n = 20 animals for EC, HTP, and CC (10M + 10F) per group