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The granulocyte colony stimulating factor pathway regulates autoantibody production in a murine induced model of systemic lupus erythematosus.

Lantow M, Sivakumar R, Zeumer L, Wasserfall C, Zheng YY, Atkinson MA, Morel L - Arthritis Res. Ther. (2013)

Bottom Line: G-CSF binding by B6.Sle2c2 leukocytes was reduced as compared to B6, which was associated with a reduced expansion in response to in vivo G-CSF treatment.G-CSF in vivo treatment also failed to mobilize bone-marrow B6.Sle2c2 neutrophils as it did for B6 neutrophils.This result was corroborated by the increased anti-dsDNA IgG production in G-CSF-treated B6.TC mice, which also carry the Sle2c2 locus.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Introduction: An NZB-derived genetic locus (Sle2c2) that suppresses autoantibody production in a mouse model of induced systemic lupus erythematosus contains a polymorphism in the gene encoding the G-CSF receptor. This study was designed to test the hypothesis that the Sle2c2 suppression is associated with an impaired G-CSF receptor function that can be overcome by exogenous G-CSF.

Methods: Leukocytes from B6.Sle2c2 and B6 congenic mice, which carry a different allele of the G-CSF receptor, were compared for their responses to G-CSF. Autoantibody production was induced with the chronic graft-versus-host-disease (cGVHD) model by adoptive transfer of B6.bm12 splenocytes. Different treatment regimens varying the amount and frequency of G-CSF (Neulasta®) or carrier control were tested on cGVHD outcomes. Autoantibody production, immune cell activation, and reactive oxygen species (ROS) production were compared between the two strains with the various treatments. In addition, the effect of G-CSF treatment was examined on the production autoantibodies in the B6.Sle1.Sle2.Sle3 (B6.TC) spontaneous model of lupus.

Results: B6.Sle2c2 and B6 leukocytes responded differently to G-CSF. G-CSF binding by B6.Sle2c2 leukocytes was reduced as compared to B6, which was associated with a reduced expansion in response to in vivo G-CSF treatment. G-CSF in vivo treatment also failed to mobilize bone-marrow B6.Sle2c2 neutrophils as it did for B6 neutrophils. In contrast, the expression of G-CSF responsive genes indicated a higher G-CSF receptor signaling in B6.Sle2c2 cells. G-CSF treatment restored the ability of B6.Sle2c2 mice to produce autoantibodies in a dose-dependent manner upon cGVHD induction, which correlated with restored CD4+ T cells activation, as well as dendritic cell and granulocyte expansion. Steady-state ROS production was higher in B6.Sle2c2 than in B6 mice. cGVHD induction resulted in a larger increase in ROS production in B6 than in B6.Sle2c2 mice, and this difference was eliminated with G-CSF treatment. Finally, a low dose G-CSF treatment accelerated the production of anti-dsDNA IgG in young B6.TC mice.

Conclusion: The different in vivo and in vitro responses of B6.Sle2c2 leukocytes are consistent with the mutation in the G-CSFR having functional consequences. The elimination of Sle2c2 suppression of autoantibody production by exogenous G-CSF indicates that Sle2c2 corresponds to a loss of function of G-CSF receptor. This result was corroborated by the increased anti-dsDNA IgG production in G-CSF-treated B6.TC mice, which also carry the Sle2c2 locus. Overall, these results suggest that the G-CSF pathway regulates the production of autoantibodies in murine models of lupus.

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Restoration of chronic graft vs host disease (Cgvhd)-induced autoantibody (autoAb) by human granulocyte-colony stimulation factor (huG-CSF) correlates with CD4+ T cell activation, as well as DC and GR-1+ cell expansion. (A) huG-CSF 12 × 2 treatment increased CD69 expression, reduced the percentage of naïve CD62L+ CD44- CD4+ T cells and expanded the percentage of the CD62L- CD44+ effector memory CD4+ T cells in B6.Sle2c2 mice compared to dextrose-treated controls. (B) huG-CSF 12 × 2 treatment increased the percentage of CD11b+ CD11c+, GR1hi CD11b+ and GR1lo CD11b+ cells in B6.Sle2c2 mice compared to dextrose-treated controls. Means and standard error of the mean are shown with the significance value from Dunnett's multiple comparison tests between groups with five mice per group (*P < 0.05; **P < 0.01; ***P < 0.001).
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Figure 5: Restoration of chronic graft vs host disease (Cgvhd)-induced autoantibody (autoAb) by human granulocyte-colony stimulation factor (huG-CSF) correlates with CD4+ T cell activation, as well as DC and GR-1+ cell expansion. (A) huG-CSF 12 × 2 treatment increased CD69 expression, reduced the percentage of naïve CD62L+ CD44- CD4+ T cells and expanded the percentage of the CD62L- CD44+ effector memory CD4+ T cells in B6.Sle2c2 mice compared to dextrose-treated controls. (B) huG-CSF 12 × 2 treatment increased the percentage of CD11b+ CD11c+, GR1hi CD11b+ and GR1lo CD11b+ cells in B6.Sle2c2 mice compared to dextrose-treated controls. Means and standard error of the mean are shown with the significance value from Dunnett's multiple comparison tests between groups with five mice per group (*P < 0.05; **P < 0.01; ***P < 0.001).

Mentions: cGVHD increases the percentage of blasts and the expression of activation markers such as class II MHC, CD22 and CD69 on B6 but not on B6.Sle2c2 B cells [5]. Treatment with huG-CSF has minimal effects on these B cell parameters (data not shown). It decreased CD22 expression in a dose-dependent fashion on B6 but not in B6.Sle2c2 B cells. However, these changes in B cell activation did not correspond to the observed changes in autoAb production. This suggested that huG-CSF did not restore the cGVHD response through B cells. Host CD4+ T cells are also activated by cGVHD in B6 but not in B6.Sle2c2 mice [5]. B6.Sle2c2 mice have a significantly greater percentage of splenic CD4+ T cells 3 weeks after cGVHD induction (21.58 ± 0.66% vs 16.35 ± 0.48%, P < 0.001). All huG-CSF treatments reduced the size of the CD4+ T cell compartment in both strains, and the 12 × 2 treatment, which was the most successful in restoring a cGVHD response in B6.Sle2c2 mice, resulted in an equivalent percentage of CD4+ T cells between strains (17.19 ± 0.55% vs 16.18 ± 0.11%, P > 0.05). The 12 × 2 treatment also significantly increased the percentage of CD4+ T cell blasts in B6.Sle2c2 mice (controls: B6.Sle2c2: 8.54 ± 0.54% vs B6: 16.57 ± 0.75%, P > 0.0001; 12 × 2: 14.50 ± 1.26% vs 15.64 ± 1.89%, P > 0.05), increased CD69 expression, and reduced the naïve and expanded the effector memory CD4+ T cells in B6.Sle2c2 mice (Figure 5A). The similar values in 12 × 2 treated B6 and B6.Sle2c2 mice correlated with restored autoAb production in the B6.Sle2c2 mice (Figure 4). The percentage of naïve CD4+ T cells was still higher in treated B6.Sle2c2 than in treated B6 spleens, yet the difference was smaller than in untreated mice (1.43- vs 2.15-fold). The huG-CSF treatments (12 × 3 and 1.2 × 3) that did not restore autoAbs production in B6.Sle2c2 mice had no effect on CD4+ T cell activation (data not shown).


The granulocyte colony stimulating factor pathway regulates autoantibody production in a murine induced model of systemic lupus erythematosus.

Lantow M, Sivakumar R, Zeumer L, Wasserfall C, Zheng YY, Atkinson MA, Morel L - Arthritis Res. Ther. (2013)

Restoration of chronic graft vs host disease (Cgvhd)-induced autoantibody (autoAb) by human granulocyte-colony stimulation factor (huG-CSF) correlates with CD4+ T cell activation, as well as DC and GR-1+ cell expansion. (A) huG-CSF 12 × 2 treatment increased CD69 expression, reduced the percentage of naïve CD62L+ CD44- CD4+ T cells and expanded the percentage of the CD62L- CD44+ effector memory CD4+ T cells in B6.Sle2c2 mice compared to dextrose-treated controls. (B) huG-CSF 12 × 2 treatment increased the percentage of CD11b+ CD11c+, GR1hi CD11b+ and GR1lo CD11b+ cells in B6.Sle2c2 mice compared to dextrose-treated controls. Means and standard error of the mean are shown with the significance value from Dunnett's multiple comparison tests between groups with five mice per group (*P < 0.05; **P < 0.01; ***P < 0.001).
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Figure 5: Restoration of chronic graft vs host disease (Cgvhd)-induced autoantibody (autoAb) by human granulocyte-colony stimulation factor (huG-CSF) correlates with CD4+ T cell activation, as well as DC and GR-1+ cell expansion. (A) huG-CSF 12 × 2 treatment increased CD69 expression, reduced the percentage of naïve CD62L+ CD44- CD4+ T cells and expanded the percentage of the CD62L- CD44+ effector memory CD4+ T cells in B6.Sle2c2 mice compared to dextrose-treated controls. (B) huG-CSF 12 × 2 treatment increased the percentage of CD11b+ CD11c+, GR1hi CD11b+ and GR1lo CD11b+ cells in B6.Sle2c2 mice compared to dextrose-treated controls. Means and standard error of the mean are shown with the significance value from Dunnett's multiple comparison tests between groups with five mice per group (*P < 0.05; **P < 0.01; ***P < 0.001).
Mentions: cGVHD increases the percentage of blasts and the expression of activation markers such as class II MHC, CD22 and CD69 on B6 but not on B6.Sle2c2 B cells [5]. Treatment with huG-CSF has minimal effects on these B cell parameters (data not shown). It decreased CD22 expression in a dose-dependent fashion on B6 but not in B6.Sle2c2 B cells. However, these changes in B cell activation did not correspond to the observed changes in autoAb production. This suggested that huG-CSF did not restore the cGVHD response through B cells. Host CD4+ T cells are also activated by cGVHD in B6 but not in B6.Sle2c2 mice [5]. B6.Sle2c2 mice have a significantly greater percentage of splenic CD4+ T cells 3 weeks after cGVHD induction (21.58 ± 0.66% vs 16.35 ± 0.48%, P < 0.001). All huG-CSF treatments reduced the size of the CD4+ T cell compartment in both strains, and the 12 × 2 treatment, which was the most successful in restoring a cGVHD response in B6.Sle2c2 mice, resulted in an equivalent percentage of CD4+ T cells between strains (17.19 ± 0.55% vs 16.18 ± 0.11%, P > 0.05). The 12 × 2 treatment also significantly increased the percentage of CD4+ T cell blasts in B6.Sle2c2 mice (controls: B6.Sle2c2: 8.54 ± 0.54% vs B6: 16.57 ± 0.75%, P > 0.0001; 12 × 2: 14.50 ± 1.26% vs 15.64 ± 1.89%, P > 0.05), increased CD69 expression, and reduced the naïve and expanded the effector memory CD4+ T cells in B6.Sle2c2 mice (Figure 5A). The similar values in 12 × 2 treated B6 and B6.Sle2c2 mice correlated with restored autoAb production in the B6.Sle2c2 mice (Figure 4). The percentage of naïve CD4+ T cells was still higher in treated B6.Sle2c2 than in treated B6 spleens, yet the difference was smaller than in untreated mice (1.43- vs 2.15-fold). The huG-CSF treatments (12 × 3 and 1.2 × 3) that did not restore autoAbs production in B6.Sle2c2 mice had no effect on CD4+ T cell activation (data not shown).

Bottom Line: G-CSF binding by B6.Sle2c2 leukocytes was reduced as compared to B6, which was associated with a reduced expansion in response to in vivo G-CSF treatment.G-CSF in vivo treatment also failed to mobilize bone-marrow B6.Sle2c2 neutrophils as it did for B6 neutrophils.This result was corroborated by the increased anti-dsDNA IgG production in G-CSF-treated B6.TC mice, which also carry the Sle2c2 locus.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Introduction: An NZB-derived genetic locus (Sle2c2) that suppresses autoantibody production in a mouse model of induced systemic lupus erythematosus contains a polymorphism in the gene encoding the G-CSF receptor. This study was designed to test the hypothesis that the Sle2c2 suppression is associated with an impaired G-CSF receptor function that can be overcome by exogenous G-CSF.

Methods: Leukocytes from B6.Sle2c2 and B6 congenic mice, which carry a different allele of the G-CSF receptor, were compared for their responses to G-CSF. Autoantibody production was induced with the chronic graft-versus-host-disease (cGVHD) model by adoptive transfer of B6.bm12 splenocytes. Different treatment regimens varying the amount and frequency of G-CSF (Neulasta®) or carrier control were tested on cGVHD outcomes. Autoantibody production, immune cell activation, and reactive oxygen species (ROS) production were compared between the two strains with the various treatments. In addition, the effect of G-CSF treatment was examined on the production autoantibodies in the B6.Sle1.Sle2.Sle3 (B6.TC) spontaneous model of lupus.

Results: B6.Sle2c2 and B6 leukocytes responded differently to G-CSF. G-CSF binding by B6.Sle2c2 leukocytes was reduced as compared to B6, which was associated with a reduced expansion in response to in vivo G-CSF treatment. G-CSF in vivo treatment also failed to mobilize bone-marrow B6.Sle2c2 neutrophils as it did for B6 neutrophils. In contrast, the expression of G-CSF responsive genes indicated a higher G-CSF receptor signaling in B6.Sle2c2 cells. G-CSF treatment restored the ability of B6.Sle2c2 mice to produce autoantibodies in a dose-dependent manner upon cGVHD induction, which correlated with restored CD4+ T cells activation, as well as dendritic cell and granulocyte expansion. Steady-state ROS production was higher in B6.Sle2c2 than in B6 mice. cGVHD induction resulted in a larger increase in ROS production in B6 than in B6.Sle2c2 mice, and this difference was eliminated with G-CSF treatment. Finally, a low dose G-CSF treatment accelerated the production of anti-dsDNA IgG in young B6.TC mice.

Conclusion: The different in vivo and in vitro responses of B6.Sle2c2 leukocytes are consistent with the mutation in the G-CSFR having functional consequences. The elimination of Sle2c2 suppression of autoantibody production by exogenous G-CSF indicates that Sle2c2 corresponds to a loss of function of G-CSF receptor. This result was corroborated by the increased anti-dsDNA IgG production in G-CSF-treated B6.TC mice, which also carry the Sle2c2 locus. Overall, these results suggest that the G-CSF pathway regulates the production of autoantibodies in murine models of lupus.

Show MeSH
Related in: MedlinePlus