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IgG1 protects against renal disease in a mouse model of cryoglobulinaemia.

Strait RT, Posgai MT, Mahler A, Barasa N, Jacob CO, Köhl J, Ehlers M, Stringer K, Shanmukhappa SK, Witte D, Hossain MM, Khodoun M, Herr AB, Finkelman FD - Nature (2014)

Bottom Line: Immunoglobulins protect against disease to a considerable extent by activating complement and stimulatory immunoglobulin crystallizable fragment receptors (Ig FcRs), and aggregating microbial pathogens.Yet IgG1, the predominant murine serum Ig isotype, cannot activate complement by the classical pathway, binds more avidly to an inhibitory than to stimulatory FcRs, and has limited ability to aggregate pathogens.In these regards, it resembles human IgG4 (ref. 4).

View Article: PubMed Central - PubMed

Affiliation: 1] Division of Emergency Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA [2] Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA.

ABSTRACT
Immunoglobulins protect against disease to a considerable extent by activating complement and stimulatory immunoglobulin crystallizable fragment receptors (Ig FcRs), and aggregating microbial pathogens. Yet IgG1, the predominant murine serum Ig isotype, cannot activate complement by the classical pathway, binds more avidly to an inhibitory than to stimulatory FcRs, and has limited ability to aggregate pathogens. In these regards, it resembles human IgG4 (ref. 4). We hypothesized that limited ability to activate effector mechanisms might protect against immune complex immunopathology. Here we show that IgG1-deficient (γ1(-)) mice, immunized with a potent antigen, develop lethal renal disease soon after they begin to produce antigen-specific antibody, whereas similarly immunized wild-type mice remain healthy. Surprisingly, renal disease in this model is complement and FcR independent and results from immune complex precipitation in glomerular capillaries, as in some cryoglobulinaemic humans. IgG3, which self-associates to form large immune complexes, accounts for more than 97% of the mouse Ig in this cryoglobulin; furthermore, glomerular disease develops when mice are injected with IgG3 anti-trinitrophenyl (TNP) monoclonal antibody followed by a TNP-labelled protein. Renal disease is prevented in both active and passive immunization models by antigen-specific IgG1; other isotypes are less potent at preventing disease. These observations demonstrate the adaptive significance of Ig isotypes that poorly activate effector mechanisms, reveal an immune-complex-dependent, complement- and FcR-independent nephrotoxic mechanism, and suggest that isotypes that poorly activate effector mechanisms may be useful for inhibiting immune complex immunopathology.

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Ag-specific IgG1 prevents IgG3-mediated glomerulopathyBALB/c γ1- mice (5/gp) were injected with GaMD on day 0 and/or GaMD-immune or rabbit anti-mouse IgD (RaMD) immune WT serum daily on d4-7. a,b, Urine protein (a) and d12 serum albumin and BUN levels (b). * p<0.05, **p<0.005, NS = not significant. c, BALB/c γ1- mice (5/gp) were injected with GaMD on d0 ± GaMD immune WT serum daily on d4-7 or 5-7. Spleens were harvested and cultured on d8; 24 hr culture supernatant IgG2a, IgG3, and IgM anti-goat IgG titers were determined. No anti-goat IgG Ab was detected in culture supernatants from non-immune spleen cells. d, WT and C3-deficient (C3-) mice (4/gp) were injected s.c. with 100 μl of TNP-goat serum and i.v. with 4 mg of mouse IgG3 anti-TNP ± 5 mg of IgG1 anti-TNP mAbs on d0 and 1. Urine was analyzed on d0, 1 and 2. e, WT and FcγRIIB-deficient (FcγRIIB-) mice (4/gp) were injected s.c. with 100 μl of TNP-goat serum and i.v. with 4 mg of IgG3 anti-TNP ± 5 mg of IgG1 anti-TNP on d0 and 1. Urinalysis on d0, 1 and 2. f, BALB/c mice were injected i.v.with 4 mg IgG3 anti-TNP and s.c. with 1.4 mg of TNP-BSA on days 0 and 1. Some mice were also injected with 0.625, 1.25, 2.5, or 5 mg of switch variant IgG1, IgG2a or IgG2b anti-TNP mAbs on d0 and 1. Urine protein was determined on d0 (not shown), d1 (upper panel) and d2 (lower panel). Results are pooled from a total of 7 experiments. Group size: IgG3 alone: 19 mice; 0.625 mg of IgG1, IgG2a, or IgG2b: 4 mice; 1.25 mg of IgG1, IgG2a or IgG2b: 8 mice; 2.5 mg of IgG1, IgG2a or IgG2b: 6 mice; 5 mg of IgG1, IgG2a or IgG2b: 8 or 9 mice. The significance of differences between treatment groups was determined with a normal regression model with the covariates: group, dose and group-dose interaction; a t-test was used to evaluate the significance of the difference in least square means for each of these effects. This procedure was used to evaluate urine protein, measured at day 1 and day 2. A p-value less than or equal to 0.05 after applying the Tukey adjustment for multiple comparisons was judged to be significant. # p<0.05 as compared to IgG2a plus IgG3. +p<0.05 as compared to IgG2b plus IgG3. *p<0.05 as compared to IgG3 alone.
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Figure 14: Ag-specific IgG1 prevents IgG3-mediated glomerulopathyBALB/c γ1- mice (5/gp) were injected with GaMD on day 0 and/or GaMD-immune or rabbit anti-mouse IgD (RaMD) immune WT serum daily on d4-7. a,b, Urine protein (a) and d12 serum albumin and BUN levels (b). * p<0.05, **p<0.005, NS = not significant. c, BALB/c γ1- mice (5/gp) were injected with GaMD on d0 ± GaMD immune WT serum daily on d4-7 or 5-7. Spleens were harvested and cultured on d8; 24 hr culture supernatant IgG2a, IgG3, and IgM anti-goat IgG titers were determined. No anti-goat IgG Ab was detected in culture supernatants from non-immune spleen cells. d, WT and C3-deficient (C3-) mice (4/gp) were injected s.c. with 100 μl of TNP-goat serum and i.v. with 4 mg of mouse IgG3 anti-TNP ± 5 mg of IgG1 anti-TNP mAbs on d0 and 1. Urine was analyzed on d0, 1 and 2. e, WT and FcγRIIB-deficient (FcγRIIB-) mice (4/gp) were injected s.c. with 100 μl of TNP-goat serum and i.v. with 4 mg of IgG3 anti-TNP ± 5 mg of IgG1 anti-TNP on d0 and 1. Urinalysis on d0, 1 and 2. f, BALB/c mice were injected i.v.with 4 mg IgG3 anti-TNP and s.c. with 1.4 mg of TNP-BSA on days 0 and 1. Some mice were also injected with 0.625, 1.25, 2.5, or 5 mg of switch variant IgG1, IgG2a or IgG2b anti-TNP mAbs on d0 and 1. Urine protein was determined on d0 (not shown), d1 (upper panel) and d2 (lower panel). Results are pooled from a total of 7 experiments. Group size: IgG3 alone: 19 mice; 0.625 mg of IgG1, IgG2a, or IgG2b: 4 mice; 1.25 mg of IgG1, IgG2a or IgG2b: 8 mice; 2.5 mg of IgG1, IgG2a or IgG2b: 6 mice; 5 mg of IgG1, IgG2a or IgG2b: 8 or 9 mice. The significance of differences between treatment groups was determined with a normal regression model with the covariates: group, dose and group-dose interaction; a t-test was used to evaluate the significance of the difference in least square means for each of these effects. This procedure was used to evaluate urine protein, measured at day 1 and day 2. A p-value less than or equal to 0.05 after applying the Tukey adjustment for multiple comparisons was judged to be significant. # p<0.05 as compared to IgG2a plus IgG3. +p<0.05 as compared to IgG2b plus IgG3. *p<0.05 as compared to IgG3 alone.

Mentions: The unique pathogenicity of IgG3 raised the possibility that the other IgG isotypes might be able to inhibit IgG3-mediated disease. Consistent with this, GaMD induced only transient renal disease in γ1+/- mice, which produced ∼50% as much IgG1 as WT (γ1+/+) mice, but similar IgG3 as γ1-/- mice (Extended Data Fig. 8). Similarly, development of proteinuria, hypoalbuminemia and azotemia in GaMD-immunized γ1-/- mice was suppressed by administration of the IgG1 anti-GIgG-rich serum from GaMD-immunized WT mice (GaMD immune WT serum). This suppression was Ag-specific, because it was not observed with serum from rabbit anti-mouse IgD-immunized WT mice (RaMD immune WT serum) (Figs. 4a and b). Disease suppression by GaMD immune WT serum required initiation of treatment by day 5 after GaMD immunization (Extended Data Fig. 9a), when immunized mice first secrete IgG anti-GIgG. Importantly, injection of GaMD immune WT serum starting 4-5 days after GaMD immunization suppressed renal disease in γ1- mice without decreasing serum IgM, IgG2a or IgG3 levels and only modestly decreased production of any isotype by cultured spleen cells (Fig. 4c and Extended Data Fig. 9b). Thus, IgG1 primarily suppresses renal disease in our model by competing with IgG3 for Ag epitopes and/or changing the solubility of ICs rather than by decreasing IgG3 secretion; and the increased IgG3 secretion by GaMD-immunized γ1- mice results from blocked isotype switching rather than from a lack of IgG1.


IgG1 protects against renal disease in a mouse model of cryoglobulinaemia.

Strait RT, Posgai MT, Mahler A, Barasa N, Jacob CO, Köhl J, Ehlers M, Stringer K, Shanmukhappa SK, Witte D, Hossain MM, Khodoun M, Herr AB, Finkelman FD - Nature (2014)

Ag-specific IgG1 prevents IgG3-mediated glomerulopathyBALB/c γ1- mice (5/gp) were injected with GaMD on day 0 and/or GaMD-immune or rabbit anti-mouse IgD (RaMD) immune WT serum daily on d4-7. a,b, Urine protein (a) and d12 serum albumin and BUN levels (b). * p<0.05, **p<0.005, NS = not significant. c, BALB/c γ1- mice (5/gp) were injected with GaMD on d0 ± GaMD immune WT serum daily on d4-7 or 5-7. Spleens were harvested and cultured on d8; 24 hr culture supernatant IgG2a, IgG3, and IgM anti-goat IgG titers were determined. No anti-goat IgG Ab was detected in culture supernatants from non-immune spleen cells. d, WT and C3-deficient (C3-) mice (4/gp) were injected s.c. with 100 μl of TNP-goat serum and i.v. with 4 mg of mouse IgG3 anti-TNP ± 5 mg of IgG1 anti-TNP mAbs on d0 and 1. Urine was analyzed on d0, 1 and 2. e, WT and FcγRIIB-deficient (FcγRIIB-) mice (4/gp) were injected s.c. with 100 μl of TNP-goat serum and i.v. with 4 mg of IgG3 anti-TNP ± 5 mg of IgG1 anti-TNP on d0 and 1. Urinalysis on d0, 1 and 2. f, BALB/c mice were injected i.v.with 4 mg IgG3 anti-TNP and s.c. with 1.4 mg of TNP-BSA on days 0 and 1. Some mice were also injected with 0.625, 1.25, 2.5, or 5 mg of switch variant IgG1, IgG2a or IgG2b anti-TNP mAbs on d0 and 1. Urine protein was determined on d0 (not shown), d1 (upper panel) and d2 (lower panel). Results are pooled from a total of 7 experiments. Group size: IgG3 alone: 19 mice; 0.625 mg of IgG1, IgG2a, or IgG2b: 4 mice; 1.25 mg of IgG1, IgG2a or IgG2b: 8 mice; 2.5 mg of IgG1, IgG2a or IgG2b: 6 mice; 5 mg of IgG1, IgG2a or IgG2b: 8 or 9 mice. The significance of differences between treatment groups was determined with a normal regression model with the covariates: group, dose and group-dose interaction; a t-test was used to evaluate the significance of the difference in least square means for each of these effects. This procedure was used to evaluate urine protein, measured at day 1 and day 2. A p-value less than or equal to 0.05 after applying the Tukey adjustment for multiple comparisons was judged to be significant. # p<0.05 as compared to IgG2a plus IgG3. +p<0.05 as compared to IgG2b plus IgG3. *p<0.05 as compared to IgG3 alone.
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Figure 14: Ag-specific IgG1 prevents IgG3-mediated glomerulopathyBALB/c γ1- mice (5/gp) were injected with GaMD on day 0 and/or GaMD-immune or rabbit anti-mouse IgD (RaMD) immune WT serum daily on d4-7. a,b, Urine protein (a) and d12 serum albumin and BUN levels (b). * p<0.05, **p<0.005, NS = not significant. c, BALB/c γ1- mice (5/gp) were injected with GaMD on d0 ± GaMD immune WT serum daily on d4-7 or 5-7. Spleens were harvested and cultured on d8; 24 hr culture supernatant IgG2a, IgG3, and IgM anti-goat IgG titers were determined. No anti-goat IgG Ab was detected in culture supernatants from non-immune spleen cells. d, WT and C3-deficient (C3-) mice (4/gp) were injected s.c. with 100 μl of TNP-goat serum and i.v. with 4 mg of mouse IgG3 anti-TNP ± 5 mg of IgG1 anti-TNP mAbs on d0 and 1. Urine was analyzed on d0, 1 and 2. e, WT and FcγRIIB-deficient (FcγRIIB-) mice (4/gp) were injected s.c. with 100 μl of TNP-goat serum and i.v. with 4 mg of IgG3 anti-TNP ± 5 mg of IgG1 anti-TNP on d0 and 1. Urinalysis on d0, 1 and 2. f, BALB/c mice were injected i.v.with 4 mg IgG3 anti-TNP and s.c. with 1.4 mg of TNP-BSA on days 0 and 1. Some mice were also injected with 0.625, 1.25, 2.5, or 5 mg of switch variant IgG1, IgG2a or IgG2b anti-TNP mAbs on d0 and 1. Urine protein was determined on d0 (not shown), d1 (upper panel) and d2 (lower panel). Results are pooled from a total of 7 experiments. Group size: IgG3 alone: 19 mice; 0.625 mg of IgG1, IgG2a, or IgG2b: 4 mice; 1.25 mg of IgG1, IgG2a or IgG2b: 8 mice; 2.5 mg of IgG1, IgG2a or IgG2b: 6 mice; 5 mg of IgG1, IgG2a or IgG2b: 8 or 9 mice. The significance of differences between treatment groups was determined with a normal regression model with the covariates: group, dose and group-dose interaction; a t-test was used to evaluate the significance of the difference in least square means for each of these effects. This procedure was used to evaluate urine protein, measured at day 1 and day 2. A p-value less than or equal to 0.05 after applying the Tukey adjustment for multiple comparisons was judged to be significant. # p<0.05 as compared to IgG2a plus IgG3. +p<0.05 as compared to IgG2b plus IgG3. *p<0.05 as compared to IgG3 alone.
Mentions: The unique pathogenicity of IgG3 raised the possibility that the other IgG isotypes might be able to inhibit IgG3-mediated disease. Consistent with this, GaMD induced only transient renal disease in γ1+/- mice, which produced ∼50% as much IgG1 as WT (γ1+/+) mice, but similar IgG3 as γ1-/- mice (Extended Data Fig. 8). Similarly, development of proteinuria, hypoalbuminemia and azotemia in GaMD-immunized γ1-/- mice was suppressed by administration of the IgG1 anti-GIgG-rich serum from GaMD-immunized WT mice (GaMD immune WT serum). This suppression was Ag-specific, because it was not observed with serum from rabbit anti-mouse IgD-immunized WT mice (RaMD immune WT serum) (Figs. 4a and b). Disease suppression by GaMD immune WT serum required initiation of treatment by day 5 after GaMD immunization (Extended Data Fig. 9a), when immunized mice first secrete IgG anti-GIgG. Importantly, injection of GaMD immune WT serum starting 4-5 days after GaMD immunization suppressed renal disease in γ1- mice without decreasing serum IgM, IgG2a or IgG3 levels and only modestly decreased production of any isotype by cultured spleen cells (Fig. 4c and Extended Data Fig. 9b). Thus, IgG1 primarily suppresses renal disease in our model by competing with IgG3 for Ag epitopes and/or changing the solubility of ICs rather than by decreasing IgG3 secretion; and the increased IgG3 secretion by GaMD-immunized γ1- mice results from blocked isotype switching rather than from a lack of IgG1.

Bottom Line: Immunoglobulins protect against disease to a considerable extent by activating complement and stimulatory immunoglobulin crystallizable fragment receptors (Ig FcRs), and aggregating microbial pathogens.Yet IgG1, the predominant murine serum Ig isotype, cannot activate complement by the classical pathway, binds more avidly to an inhibitory than to stimulatory FcRs, and has limited ability to aggregate pathogens.In these regards, it resembles human IgG4 (ref. 4).

View Article: PubMed Central - PubMed

Affiliation: 1] Division of Emergency Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA [2] Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA.

ABSTRACT
Immunoglobulins protect against disease to a considerable extent by activating complement and stimulatory immunoglobulin crystallizable fragment receptors (Ig FcRs), and aggregating microbial pathogens. Yet IgG1, the predominant murine serum Ig isotype, cannot activate complement by the classical pathway, binds more avidly to an inhibitory than to stimulatory FcRs, and has limited ability to aggregate pathogens. In these regards, it resembles human IgG4 (ref. 4). We hypothesized that limited ability to activate effector mechanisms might protect against immune complex immunopathology. Here we show that IgG1-deficient (γ1(-)) mice, immunized with a potent antigen, develop lethal renal disease soon after they begin to produce antigen-specific antibody, whereas similarly immunized wild-type mice remain healthy. Surprisingly, renal disease in this model is complement and FcR independent and results from immune complex precipitation in glomerular capillaries, as in some cryoglobulinaemic humans. IgG3, which self-associates to form large immune complexes, accounts for more than 97% of the mouse Ig in this cryoglobulin; furthermore, glomerular disease develops when mice are injected with IgG3 anti-trinitrophenyl (TNP) monoclonal antibody followed by a TNP-labelled protein. Renal disease is prevented in both active and passive immunization models by antigen-specific IgG1; other isotypes are less potent at preventing disease. These observations demonstrate the adaptive significance of Ig isotypes that poorly activate effector mechanisms, reveal an immune-complex-dependent, complement- and FcR-independent nephrotoxic mechanism, and suggest that isotypes that poorly activate effector mechanisms may be useful for inhibiting immune complex immunopathology.

Show MeSH
Related in: MedlinePlus