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The C5a receptor has a key role in immune complex glomerulonephritis in complement factor H-deficient mice.

Alexander JJ, Chaves L, Chang A, Quigg RJ - Kidney Int. (2012)

Bottom Line: Chronic serum sickness leads to the formation of glomerular immune complexes; however, C57BL/6 mice do not develop glomerulonephritis unless complement factor H (CFH) is absent from the plasma.Here we studied the role for C5a receptor (R) in this setting.There was no interstitial inflammation by histologic criteria or flow cytometry for F4/80+ Ly6C(hi)CCR2(hi) inflammatory macrophages.

View Article: PubMed Central - PubMed

Affiliation: Section of Nephrology, Department of Medicine, The University of Chicago, Chicago, Illinois 60637, USA. jalexand@medicine.bsd.uchicago.edu

ABSTRACT
Chronic serum sickness leads to the formation of glomerular immune complexes; however, C57BL/6 mice do not develop glomerulonephritis unless complement factor H (CFH) is absent from the plasma. Here we studied the role for C5a receptor (R) in this setting. The exaggerated humoral immune response in CFH(-/-) mice was normalized in CFH(-/-)C5aR(-/-) double knockout mice, highlighting the C5aR dependence. The CFH knockout mice developed proliferative glomerulonephritis with endocapillary F4/80+ macrophage infiltration, a process reduced in the double knockout mice. There was no interstitial inflammation by histologic criteria or flow cytometry for F4/80+ Ly6C(hi)CCR2(hi) inflammatory macrophages. There were, however, more interstitial CD3+ CD4+ T lymphocytes in CFH knockout mice with chronic serum sickness, while double knockout mice had greater than 5-fold more Ly6C(lo)CCR2(lo) anti-inflammatory macrophages compared to the CFH knockout mice. Mice lacking C5aR were significantly protected from functional renal disease as assessed by blood urea nitrogen levels. Thus, IgG- and iC3b-containing immune complexes are not inflammatory in C57BL/6 mice. Yet when these mice lack CFH, sufficient C3b persists in glomeruli to generate C5a and activate C5aR.

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Role of C5aR in interstitial macrophage (a, b) and T lymphocyte (c) numbers in CFH−/− mice after 5 weeks of active immunization with apoferritin or saline as controls. The percentage of F4/80+ kidney cells that were Ly6ChiCCR2hi or Ly6CloCCR2lo is shown graphically in a with representative flow cytometry histograms shown in b. Peripheral blood mononuclear cells were studied in parallel, allowing comparisons with kidney cells. Representative data from kidney and blood are from the same animal. Similarly, the percentage of total isolated kidney cells that were CD3+CD4+ or CD3+CD8+ was determined (there was no CD3+CD4+CD8+ population; c). All log-transformed data were normally distributed and used in statistical analyses. Individual values from all mice studied are shown (a, c), with y-axes as log scales and means as horizontal lines. All data are derived from the same pool of cells and are directly comparable, whereas the y-axis scales were varied based on data. All groups but Ly6ChiCCR2hi cells had significantly different variances by analysis of variance (P<0.015). Significant differences in follow-up statistical comparisons are shown individually. CFH, complement factor H.
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fig3: Role of C5aR in interstitial macrophage (a, b) and T lymphocyte (c) numbers in CFH−/− mice after 5 weeks of active immunization with apoferritin or saline as controls. The percentage of F4/80+ kidney cells that were Ly6ChiCCR2hi or Ly6CloCCR2lo is shown graphically in a with representative flow cytometry histograms shown in b. Peripheral blood mononuclear cells were studied in parallel, allowing comparisons with kidney cells. Representative data from kidney and blood are from the same animal. Similarly, the percentage of total isolated kidney cells that were CD3+CD4+ or CD3+CD8+ was determined (there was no CD3+CD4+CD8+ population; c). All log-transformed data were normally distributed and used in statistical analyses. Individual values from all mice studied are shown (a, c), with y-axes as log scales and means as horizontal lines. All data are derived from the same pool of cells and are directly comparable, whereas the y-axis scales were varied based on data. All groups but Ly6ChiCCR2hi cells had significantly different variances by analysis of variance (P<0.015). Significant differences in follow-up statistical comparisons are shown individually. CFH, complement factor H.

Mentions: As typical for this model,14 there was no interstitial nephritis by histopathological criteria.22 To evaluate whether there were more subtle changes in mononuclear and lymphocytic cell populations within the interstitium, a separate group of animals was studied with CSS followed by flow cytometry. F4/80+Ly6C+ cells in tissue sites are considered macrophages, and can be divided by expression levels of Ly6C and CCR2 into inflammatory M1 (Ly6ChiCCR2hi) and anti-inflammatory (or ‘alternative') M2 (Ly6CloCCR2lo) macrophages.23, 24, 25 Saline-treated controls had few Ly6ChiCCR2hi cells in kidneys, which was also true for both groups of animals with CSS (Figure 3a and b). CFH−/−C5aR−/− mice with CSS had considerably increased intrarenal Ly6CloCCR2lo cells relative to CFH−/− control and CSS groups (Figure 3a and b). Consistent with an M2 macrophage phenotype, these cells were CD115+F4/80loCD11b+CD11clo as well; they were clearly distinct from CD115−F4/80hiCD11b+CD11c+ dendritic cells (Supplementary Information online).


The C5a receptor has a key role in immune complex glomerulonephritis in complement factor H-deficient mice.

Alexander JJ, Chaves L, Chang A, Quigg RJ - Kidney Int. (2012)

Role of C5aR in interstitial macrophage (a, b) and T lymphocyte (c) numbers in CFH−/− mice after 5 weeks of active immunization with apoferritin or saline as controls. The percentage of F4/80+ kidney cells that were Ly6ChiCCR2hi or Ly6CloCCR2lo is shown graphically in a with representative flow cytometry histograms shown in b. Peripheral blood mononuclear cells were studied in parallel, allowing comparisons with kidney cells. Representative data from kidney and blood are from the same animal. Similarly, the percentage of total isolated kidney cells that were CD3+CD4+ or CD3+CD8+ was determined (there was no CD3+CD4+CD8+ population; c). All log-transformed data were normally distributed and used in statistical analyses. Individual values from all mice studied are shown (a, c), with y-axes as log scales and means as horizontal lines. All data are derived from the same pool of cells and are directly comparable, whereas the y-axis scales were varied based on data. All groups but Ly6ChiCCR2hi cells had significantly different variances by analysis of variance (P<0.015). Significant differences in follow-up statistical comparisons are shown individually. CFH, complement factor H.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472160&req=5

fig3: Role of C5aR in interstitial macrophage (a, b) and T lymphocyte (c) numbers in CFH−/− mice after 5 weeks of active immunization with apoferritin or saline as controls. The percentage of F4/80+ kidney cells that were Ly6ChiCCR2hi or Ly6CloCCR2lo is shown graphically in a with representative flow cytometry histograms shown in b. Peripheral blood mononuclear cells were studied in parallel, allowing comparisons with kidney cells. Representative data from kidney and blood are from the same animal. Similarly, the percentage of total isolated kidney cells that were CD3+CD4+ or CD3+CD8+ was determined (there was no CD3+CD4+CD8+ population; c). All log-transformed data were normally distributed and used in statistical analyses. Individual values from all mice studied are shown (a, c), with y-axes as log scales and means as horizontal lines. All data are derived from the same pool of cells and are directly comparable, whereas the y-axis scales were varied based on data. All groups but Ly6ChiCCR2hi cells had significantly different variances by analysis of variance (P<0.015). Significant differences in follow-up statistical comparisons are shown individually. CFH, complement factor H.
Mentions: As typical for this model,14 there was no interstitial nephritis by histopathological criteria.22 To evaluate whether there were more subtle changes in mononuclear and lymphocytic cell populations within the interstitium, a separate group of animals was studied with CSS followed by flow cytometry. F4/80+Ly6C+ cells in tissue sites are considered macrophages, and can be divided by expression levels of Ly6C and CCR2 into inflammatory M1 (Ly6ChiCCR2hi) and anti-inflammatory (or ‘alternative') M2 (Ly6CloCCR2lo) macrophages.23, 24, 25 Saline-treated controls had few Ly6ChiCCR2hi cells in kidneys, which was also true for both groups of animals with CSS (Figure 3a and b). CFH−/−C5aR−/− mice with CSS had considerably increased intrarenal Ly6CloCCR2lo cells relative to CFH−/− control and CSS groups (Figure 3a and b). Consistent with an M2 macrophage phenotype, these cells were CD115+F4/80loCD11b+CD11clo as well; they were clearly distinct from CD115−F4/80hiCD11b+CD11c+ dendritic cells (Supplementary Information online).

Bottom Line: Chronic serum sickness leads to the formation of glomerular immune complexes; however, C57BL/6 mice do not develop glomerulonephritis unless complement factor H (CFH) is absent from the plasma.Here we studied the role for C5a receptor (R) in this setting.There was no interstitial inflammation by histologic criteria or flow cytometry for F4/80+ Ly6C(hi)CCR2(hi) inflammatory macrophages.

View Article: PubMed Central - PubMed

Affiliation: Section of Nephrology, Department of Medicine, The University of Chicago, Chicago, Illinois 60637, USA. jalexand@medicine.bsd.uchicago.edu

ABSTRACT
Chronic serum sickness leads to the formation of glomerular immune complexes; however, C57BL/6 mice do not develop glomerulonephritis unless complement factor H (CFH) is absent from the plasma. Here we studied the role for C5a receptor (R) in this setting. The exaggerated humoral immune response in CFH(-/-) mice was normalized in CFH(-/-)C5aR(-/-) double knockout mice, highlighting the C5aR dependence. The CFH knockout mice developed proliferative glomerulonephritis with endocapillary F4/80+ macrophage infiltration, a process reduced in the double knockout mice. There was no interstitial inflammation by histologic criteria or flow cytometry for F4/80+ Ly6C(hi)CCR2(hi) inflammatory macrophages. There were, however, more interstitial CD3+ CD4+ T lymphocytes in CFH knockout mice with chronic serum sickness, while double knockout mice had greater than 5-fold more Ly6C(lo)CCR2(lo) anti-inflammatory macrophages compared to the CFH knockout mice. Mice lacking C5aR were significantly protected from functional renal disease as assessed by blood urea nitrogen levels. Thus, IgG- and iC3b-containing immune complexes are not inflammatory in C57BL/6 mice. Yet when these mice lack CFH, sufficient C3b persists in glomeruli to generate C5a and activate C5aR.

Show MeSH
Related in: MedlinePlus