LPA Promotes T Cell Recruitment through Synthesis of CXCL13

Figure 3

LPA-induced leukocyte recruitment in untreated and TNF-α-primed air pouches. (a) Kinetics of LPA-mediated leukocyte recruitment into TNF-α-treated air pouches. TNF-α (50 ng) was injected into the air pouches 16 h prior to stimulation with 3 μg LPA for the indicated times. Air pouch exudates were collected and the number of leukocytes was determined as described in Section 2. (b) Leukocyte populations in lavage fluids collected from air pouches pretreated with TNF-α for 16 h and injected with LPA for 6 h. Cells were stained with various leukocyte markers and analyzed by flow cytometry. The CD11b⁻ cells were defined as lymphocytes according to their low granularity (left panel), which stained positive for CD3 (T cells, right panel) or CD19 (B cells, middle panel). (c) Labelling of B cells isolated from mouse spleen. Splenocytes were prepared as described in Section 2 and used for titration of anti-CD3e and anti-CD19 antibodies. (d) LPA-induced CD3⁺ cell recruitment into the air pouches. Air pouch exudates were collected at 6 h after LPA injection. The total number of leukocytes was measured and that of T cells determined by flow cytometry. (e) The absolute numbers of CD3⁺ cells recruited by LPA into TNF-α-primed air pouches was evaluated as described in (d). Data are the mean ± SE from 6 mice/group. , , and by analysis of variance. SSC: side scatter; FSC: forward scatter.

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