Fig. 2

CD19-driven S1P₁ deficiency inhibits experimental HP-associated B cell accumulation in the lung. A Control and CD19^Cre± S1P₁^loxP+/+mice were exposed three consecutive days a week for three weeks to saline or 100 µg MSS and euthanized 24 h after the last exposure. Upward arrow indicates timing of euthanasia. B Gating strategy from single cell suspensions from lungs. FSC-A^low SSC-A^low cells were selected, and B cells were identified as autofluorescence low (AF⁻) B220⁺CD90⁻ lymphocytes. C Frequencies of lymphocyte subsets were multiplied by the total number of lung cells to determine the absolute numbers of B cells. D TLT area (percentage of lung area) was quantified as described in the methods after (E) hematoxylin/eosin staining of lung coronal slices. F CD69 MFI on B220⁺ cells. G Frequencies of B220⁺ cells positive for CD69. MFI: median fluorescence intensity. AF: Autofluorescence. TLT: tertiary lymphoid tissue. FMO: Fluorescence Minus One control. MSS: Methanosphaera stadtmanae. Averages ± SEM. n = 6–17. *p < 0.05