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LPA Promotes T Cell Recruitment through Synthesis of CXCL13.

Hui W, Zhao C, Bourgoin SG - Mediators Inflamm. (2015)

Bottom Line: Here we report in a murine air pouch model of inflammation that LPA induced CXCL13 secretion in a time-dependent manner and with exacerbation of the response when LPA was administered after a pretreatment with TNF-α, a key inflammatory cytokine.CXCL13 neutralization using a blocking antibody injected into air pouches prior to administration of LPA into TNF-α-primed air pouches decreased CD3(+) cell influx.Our data highlight that LPA-mediated CXCL13 secretion plays a role in T cell recruitment and participates in regulation of the inflammatory response.

View Article: PubMed Central - PubMed

Affiliation: Rheumatology and Immunology Research Center, CHU de Québec Research Center and Faculty of Medicine, Laval University, 2705 Laurier Boulevard, Québec, QC, Canada G1V 4G2.

ABSTRACT
Lysophosphatidic acid (LPA) is a bioactive phospholipid playing an important role in various inflammatory diseases by inducing expression and secretion of many inflammatory cytokines/chemokines. Here we report in a murine air pouch model of inflammation that LPA induced CXCL13 secretion in a time-dependent manner and with exacerbation of the response when LPA was administered after a pretreatment with TNF-α, a key inflammatory cytokine. LPA mediates recruitment of leukocytes, including that of CD3(+) cells into unprimed and TNF-α-primed air pouches. CXCL13 neutralization using a blocking antibody injected into air pouches prior to administration of LPA into TNF-α-primed air pouches decreased CD3(+) cell influx. Our data highlight that LPA-mediated CXCL13 secretion plays a role in T cell recruitment and participates in regulation of the inflammatory response.

No MeSH data available.


Related in: MedlinePlus

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. ∗P < 0.05, ∗∗P < 0.01, and ∗∗∗P < 0.001 by analysis of variance. SSC: side scatter; FSC: forward scatter.
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fig3: 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. ∗P < 0.05, ∗∗P < 0.01, and ∗∗∗P < 0.001 by analysis of variance. SSC: side scatter; FSC: forward scatter.

Mentions: Since CXCL13 is a ligand for CXCR5, a chemokine receptor expressed by mature B cells [19], and a subset of CD4+ and CD8+ T cells [20], we next determined whether LPA-mediated CXCL13 secretion contributes to recruitment of leukocyte subsets toward LPA into TNF-α-pretreated air pouches. As reported previously for LPA alone [11], LPA injected in TNF-α-pretreated air pouches (16 hours) stimulated the recruitment of leukocytes in a time-dependent manner (Figure 3(a)). An increase in the number of migrated leukocytes was detectable 2 h after LPA injection, peaked after 6 h, and declined thereafter. CD11b+ cells were the most prominent population in air pouch lavage fluids (Figure 3(b), left panel). We focused on CD11b− cells and performed CD19-labelling to determine by FACS whether CD19+ B lymphocytes could be detected in air pouch exudates. Even though the CD19-PE antibody labeled B cells isolated from mouse spleens (Figure 3(c)), no CD19+ B lymphocytes were detected in air pouch exudates (Figure 3(b), middle panel). However, CD11b−/CD3+ cells were detected in air pouch lavage fluids (Figure 3(b), right panel). Figure 3(d) shows that stimulation with LPA for 6 hours enhanced significantly the number of CD3+ cells in air pouch exudates (3.07 ± 0.53 × 104 cells, 1.67 ± 0.03% of total leukocytes, n = 10) compared to mice injected with vehicle alone (1.7 ± 0.32 × 104 cells, 1.88 ± 0.01% of total leukocytes, n = 10). The number of CD3+ cells in air pouch lavage fluids collected from TNF-α-pretreated air pouches was not different from that of mice injected with the vehicle alone. Furthermore, LPA injected into TNF-α-primed air pouches stimulated the recruitment of CD3+ cells in a time-dependent manner (Figure 3(e)). As observed for total leukocytes, recruitment of CD3+ cells peaked at the 6-hour time point following injection of LPA into air pouches (1.21 ± 0.19 × 105 cells, 2.5 ± 0.9% of total leukocytes, n = 5).


LPA Promotes T Cell Recruitment through Synthesis of CXCL13.

Hui W, Zhao C, Bourgoin SG - Mediators Inflamm. (2015)

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. ∗P < 0.05, ∗∗P < 0.01, and ∗∗∗P < 0.001 by analysis of variance. SSC: side scatter; FSC: forward scatter.
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig3: 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. ∗P < 0.05, ∗∗P < 0.01, and ∗∗∗P < 0.001 by analysis of variance. SSC: side scatter; FSC: forward scatter.
Mentions: Since CXCL13 is a ligand for CXCR5, a chemokine receptor expressed by mature B cells [19], and a subset of CD4+ and CD8+ T cells [20], we next determined whether LPA-mediated CXCL13 secretion contributes to recruitment of leukocyte subsets toward LPA into TNF-α-pretreated air pouches. As reported previously for LPA alone [11], LPA injected in TNF-α-pretreated air pouches (16 hours) stimulated the recruitment of leukocytes in a time-dependent manner (Figure 3(a)). An increase in the number of migrated leukocytes was detectable 2 h after LPA injection, peaked after 6 h, and declined thereafter. CD11b+ cells were the most prominent population in air pouch lavage fluids (Figure 3(b), left panel). We focused on CD11b− cells and performed CD19-labelling to determine by FACS whether CD19+ B lymphocytes could be detected in air pouch exudates. Even though the CD19-PE antibody labeled B cells isolated from mouse spleens (Figure 3(c)), no CD19+ B lymphocytes were detected in air pouch exudates (Figure 3(b), middle panel). However, CD11b−/CD3+ cells were detected in air pouch lavage fluids (Figure 3(b), right panel). Figure 3(d) shows that stimulation with LPA for 6 hours enhanced significantly the number of CD3+ cells in air pouch exudates (3.07 ± 0.53 × 104 cells, 1.67 ± 0.03% of total leukocytes, n = 10) compared to mice injected with vehicle alone (1.7 ± 0.32 × 104 cells, 1.88 ± 0.01% of total leukocytes, n = 10). The number of CD3+ cells in air pouch lavage fluids collected from TNF-α-pretreated air pouches was not different from that of mice injected with the vehicle alone. Furthermore, LPA injected into TNF-α-primed air pouches stimulated the recruitment of CD3+ cells in a time-dependent manner (Figure 3(e)). As observed for total leukocytes, recruitment of CD3+ cells peaked at the 6-hour time point following injection of LPA into air pouches (1.21 ± 0.19 × 105 cells, 2.5 ± 0.9% of total leukocytes, n = 5).

Bottom Line: Here we report in a murine air pouch model of inflammation that LPA induced CXCL13 secretion in a time-dependent manner and with exacerbation of the response when LPA was administered after a pretreatment with TNF-α, a key inflammatory cytokine.CXCL13 neutralization using a blocking antibody injected into air pouches prior to administration of LPA into TNF-α-primed air pouches decreased CD3(+) cell influx.Our data highlight that LPA-mediated CXCL13 secretion plays a role in T cell recruitment and participates in regulation of the inflammatory response.

View Article: PubMed Central - PubMed

Affiliation: Rheumatology and Immunology Research Center, CHU de Québec Research Center and Faculty of Medicine, Laval University, 2705 Laurier Boulevard, Québec, QC, Canada G1V 4G2.

ABSTRACT
Lysophosphatidic acid (LPA) is a bioactive phospholipid playing an important role in various inflammatory diseases by inducing expression and secretion of many inflammatory cytokines/chemokines. Here we report in a murine air pouch model of inflammation that LPA induced CXCL13 secretion in a time-dependent manner and with exacerbation of the response when LPA was administered after a pretreatment with TNF-α, a key inflammatory cytokine. LPA mediates recruitment of leukocytes, including that of CD3(+) cells into unprimed and TNF-α-primed air pouches. CXCL13 neutralization using a blocking antibody injected into air pouches prior to administration of LPA into TNF-α-primed air pouches decreased CD3(+) cell influx. Our data highlight that LPA-mediated CXCL13 secretion plays a role in T cell recruitment and participates in regulation of the inflammatory response.

No MeSH data available.


Related in: MedlinePlus