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Loss of intra-islet CD20 expression may complicate efficacy of B-cell-directed type 1 diabetes therapies.

Serreze DV, Chapman HD, Niens M, Dunn R, Kehry MR, Driver JP, Haller M, Wasserfall C, Atkinson MA - Diabetes (2011)

Bottom Line: One implication of these results is that the FO subset of B cells preferentially contributes to early diabetes initiation events.However, most important, the inefficient ability of anti-CD20 treatment to exert late-stage diabetes prevention was found to be attributable to downregulation of CD20 expression upon B cell entry into pancreatic islets.These findings provide important guidance for designing strategies targeting B cells as a potential means of diabetes intervention.

View Article: PubMed Central - PubMed

Affiliation: The Jackson Laboratory, Bar Harbor, Maine, USA. dave.serreze@jax.org

ABSTRACT

Objective: Consistent with studies in NOD mice, early clinical trials addressing whether depletion of B cells by the Rituximab CD20-specific antibody provides an effective means for type 1 diabetes reversal have produced promising results. However, to improve therapeutic efficacy, additional B-cell-depleting agents, as well as attempts seeking diabetes prevention, are being considered.

Research design and methods: Autoantibodies, including those against insulin (IAAs), are used to identify at-risk subjects for inclusion in diabetes prevention trials. Therefore, we tested the ability of anti-CD20 to prevent diabetes in NOD mice when administered either before or after IAA onset.

Results: The murine CD20-specific 18B12 antibody that like Rituximab, depletes the follicular (FO) but not marginal zone subset of B cells, efficiently inhibited diabetes development in NOD mice in a likely regulatory T-cell-dependent manner only when treatment was initiated before IAA detection. One implication of these results is that the FO subset of B cells preferentially contributes to early diabetes initiation events. However, most important, the inefficient ability of anti-CD20 treatment to exert late-stage diabetes prevention was found to be attributable to downregulation of CD20 expression upon B cell entry into pancreatic islets.

Conclusions: These findings provide important guidance for designing strategies targeting B cells as a potential means of diabetes intervention.

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Related in: MedlinePlus

Selective depletion of the FO subset of mature B cells limits the initiation but does efficiently abrogate already established diabetogenic autoimmune responses in NOD mice. A: Splenic MZ B cells (CD21hi CD23−) undergo a greater age-dependent expansion in NOD than B6 female mice (n = 5 per strain at each time point; P = 0.02 by ANOVA). B: Splenic FO B cells (CD21int CD23hi) undergo a greater age-dependent expansion in B6 than NOD mice (P = 0.001 by ANOVA). C and D: Treatment with the IgG1 isotype of the 18B12 murine CD20-specific antibody deletes splenic FO but not MZ B cells in NOD mice. Treatment at 21-day intervals with the CD20-specific or control antibody was initiated at 5 weeks of age in a cohort of NOD female mice. At the indicated time points, a subset of mice in each group was then assessed for numbers of splenic MZ (C) and FO (D) B cells. E: Antibody responses to exogenous antigens are marginally suppressed in NOD mice selectively depleted of FO B cells. NOD mice were treated at 10 weeks of age with the control or IgG1 CD20-specific antibody (n = 5 per group) and then primed 9 days later with HEL. Serum was collected 11 days after antigen priming and assessed by enzyme-linked immunosorbent assay for relative levels of HEL-specific antibodies. Data are represented as mean OD405 ± SEM at the indicated serum dilutions (control vs. FOB depleted: P = 0.0001 by ANOVA). MZB, MZ B cells; FOB, FO B cells; Aby, antibody.
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Figure 3: Selective depletion of the FO subset of mature B cells limits the initiation but does efficiently abrogate already established diabetogenic autoimmune responses in NOD mice. A: Splenic MZ B cells (CD21hi CD23−) undergo a greater age-dependent expansion in NOD than B6 female mice (n = 5 per strain at each time point; P = 0.02 by ANOVA). B: Splenic FO B cells (CD21int CD23hi) undergo a greater age-dependent expansion in B6 than NOD mice (P = 0.001 by ANOVA). C and D: Treatment with the IgG1 isotype of the 18B12 murine CD20-specific antibody deletes splenic FO but not MZ B cells in NOD mice. Treatment at 21-day intervals with the CD20-specific or control antibody was initiated at 5 weeks of age in a cohort of NOD female mice. At the indicated time points, a subset of mice in each group was then assessed for numbers of splenic MZ (C) and FO (D) B cells. E: Antibody responses to exogenous antigens are marginally suppressed in NOD mice selectively depleted of FO B cells. NOD mice were treated at 10 weeks of age with the control or IgG1 CD20-specific antibody (n = 5 per group) and then primed 9 days later with HEL. Serum was collected 11 days after antigen priming and assessed by enzyme-linked immunosorbent assay for relative levels of HEL-specific antibodies. Data are represented as mean OD405 ± SEM at the indicated serum dilutions (control vs. FOB depleted: P = 0.0001 by ANOVA). MZB, MZ B cells; FOB, FO B cells; Aby, antibody.

Mentions: A strain-specific and age-dependent expansion of the MZ B-cell subset has been hypothesized to be a diabetogenic component in NOD mice (22). MZ B cells are absent from peripheral blood that was monitored in the experiments described above. Thus, it was possible the poor ability of IAA-positive NOD mice to be protected from diabetes development by anti-CD20 treatment resulted from MZ B cells undergoing an age-dependent expansion, becoming refractive to deletion. To initially assess this possibility, we determined whether compared with the nonautoimmune-prone C57BL/6 (B6) strain, NOD mice housed at The Jackson Laboratory were also characterized by an age-associated expansion of splenic MZ B cells. A greater age- associated expansion of splenic MZ B cells was indeed observed in NOD than B6 mice (Fig. 3A). Conversely, mature FO subset B cells exhibited a greater age-associated expansion in B6 than NOD mice (Fig. 3B).


Loss of intra-islet CD20 expression may complicate efficacy of B-cell-directed type 1 diabetes therapies.

Serreze DV, Chapman HD, Niens M, Dunn R, Kehry MR, Driver JP, Haller M, Wasserfall C, Atkinson MA - Diabetes (2011)

Selective depletion of the FO subset of mature B cells limits the initiation but does efficiently abrogate already established diabetogenic autoimmune responses in NOD mice. A: Splenic MZ B cells (CD21hi CD23−) undergo a greater age-dependent expansion in NOD than B6 female mice (n = 5 per strain at each time point; P = 0.02 by ANOVA). B: Splenic FO B cells (CD21int CD23hi) undergo a greater age-dependent expansion in B6 than NOD mice (P = 0.001 by ANOVA). C and D: Treatment with the IgG1 isotype of the 18B12 murine CD20-specific antibody deletes splenic FO but not MZ B cells in NOD mice. Treatment at 21-day intervals with the CD20-specific or control antibody was initiated at 5 weeks of age in a cohort of NOD female mice. At the indicated time points, a subset of mice in each group was then assessed for numbers of splenic MZ (C) and FO (D) B cells. E: Antibody responses to exogenous antigens are marginally suppressed in NOD mice selectively depleted of FO B cells. NOD mice were treated at 10 weeks of age with the control or IgG1 CD20-specific antibody (n = 5 per group) and then primed 9 days later with HEL. Serum was collected 11 days after antigen priming and assessed by enzyme-linked immunosorbent assay for relative levels of HEL-specific antibodies. Data are represented as mean OD405 ± SEM at the indicated serum dilutions (control vs. FOB depleted: P = 0.0001 by ANOVA). MZB, MZ B cells; FOB, FO B cells; Aby, antibody.
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Figure 3: Selective depletion of the FO subset of mature B cells limits the initiation but does efficiently abrogate already established diabetogenic autoimmune responses in NOD mice. A: Splenic MZ B cells (CD21hi CD23−) undergo a greater age-dependent expansion in NOD than B6 female mice (n = 5 per strain at each time point; P = 0.02 by ANOVA). B: Splenic FO B cells (CD21int CD23hi) undergo a greater age-dependent expansion in B6 than NOD mice (P = 0.001 by ANOVA). C and D: Treatment with the IgG1 isotype of the 18B12 murine CD20-specific antibody deletes splenic FO but not MZ B cells in NOD mice. Treatment at 21-day intervals with the CD20-specific or control antibody was initiated at 5 weeks of age in a cohort of NOD female mice. At the indicated time points, a subset of mice in each group was then assessed for numbers of splenic MZ (C) and FO (D) B cells. E: Antibody responses to exogenous antigens are marginally suppressed in NOD mice selectively depleted of FO B cells. NOD mice were treated at 10 weeks of age with the control or IgG1 CD20-specific antibody (n = 5 per group) and then primed 9 days later with HEL. Serum was collected 11 days after antigen priming and assessed by enzyme-linked immunosorbent assay for relative levels of HEL-specific antibodies. Data are represented as mean OD405 ± SEM at the indicated serum dilutions (control vs. FOB depleted: P = 0.0001 by ANOVA). MZB, MZ B cells; FOB, FO B cells; Aby, antibody.
Mentions: A strain-specific and age-dependent expansion of the MZ B-cell subset has been hypothesized to be a diabetogenic component in NOD mice (22). MZ B cells are absent from peripheral blood that was monitored in the experiments described above. Thus, it was possible the poor ability of IAA-positive NOD mice to be protected from diabetes development by anti-CD20 treatment resulted from MZ B cells undergoing an age-dependent expansion, becoming refractive to deletion. To initially assess this possibility, we determined whether compared with the nonautoimmune-prone C57BL/6 (B6) strain, NOD mice housed at The Jackson Laboratory were also characterized by an age-associated expansion of splenic MZ B cells. A greater age- associated expansion of splenic MZ B cells was indeed observed in NOD than B6 mice (Fig. 3A). Conversely, mature FO subset B cells exhibited a greater age-associated expansion in B6 than NOD mice (Fig. 3B).

Bottom Line: One implication of these results is that the FO subset of B cells preferentially contributes to early diabetes initiation events.However, most important, the inefficient ability of anti-CD20 treatment to exert late-stage diabetes prevention was found to be attributable to downregulation of CD20 expression upon B cell entry into pancreatic islets.These findings provide important guidance for designing strategies targeting B cells as a potential means of diabetes intervention.

View Article: PubMed Central - PubMed

Affiliation: The Jackson Laboratory, Bar Harbor, Maine, USA. dave.serreze@jax.org

ABSTRACT

Objective: Consistent with studies in NOD mice, early clinical trials addressing whether depletion of B cells by the Rituximab CD20-specific antibody provides an effective means for type 1 diabetes reversal have produced promising results. However, to improve therapeutic efficacy, additional B-cell-depleting agents, as well as attempts seeking diabetes prevention, are being considered.

Research design and methods: Autoantibodies, including those against insulin (IAAs), are used to identify at-risk subjects for inclusion in diabetes prevention trials. Therefore, we tested the ability of anti-CD20 to prevent diabetes in NOD mice when administered either before or after IAA onset.

Results: The murine CD20-specific 18B12 antibody that like Rituximab, depletes the follicular (FO) but not marginal zone subset of B cells, efficiently inhibited diabetes development in NOD mice in a likely regulatory T-cell-dependent manner only when treatment was initiated before IAA detection. One implication of these results is that the FO subset of B cells preferentially contributes to early diabetes initiation events. However, most important, the inefficient ability of anti-CD20 treatment to exert late-stage diabetes prevention was found to be attributable to downregulation of CD20 expression upon B cell entry into pancreatic islets.

Conclusions: These findings provide important guidance for designing strategies targeting B cells as a potential means of diabetes intervention.

Show MeSH
Related in: MedlinePlus