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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

B cells entering pancreatic islets in NOD mice become CD20-negative plasma cells. A: Proportion of total B cells in pancreatic islet–associated leukocytes from 7- or 13-week-old untreated NOD female mice. B: Proportion of total B cells in pancreatic islet–associated leukocytes from 7- or 13-week-old NOD female mice treated 2 weeks earlier with anti-CD20. Noted statistical significance values in A and B were determined by ANOVA analyses. C: Pancreatic islet–infiltrating B cells in 13-week-old untreated NOD control mice acquire a CD20-negative phenotype (right panel). B cells in PLNs were assessed as a CD20-staining positive control (left panel). Flow cytometric profiles are shown for B220 gated cells. D: CD20-negative pancreatic islet–associated B cells in untreated NOD mice convert to a CD138-positive plasma cell phenotype (right panel). B cells in PLNs were analyzed as a control (left panel). Flow cytometric profiles are shown for B220 gated cells.
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Figure 4: B cells entering pancreatic islets in NOD mice become CD20-negative plasma cells. A: Proportion of total B cells in pancreatic islet–associated leukocytes from 7- or 13-week-old untreated NOD female mice. B: Proportion of total B cells in pancreatic islet–associated leukocytes from 7- or 13-week-old NOD female mice treated 2 weeks earlier with anti-CD20. Noted statistical significance values in A and B were determined by ANOVA analyses. C: Pancreatic islet–infiltrating B cells in 13-week-old untreated NOD control mice acquire a CD20-negative phenotype (right panel). B cells in PLNs were assessed as a CD20-staining positive control (left panel). Flow cytometric profiles are shown for B220 gated cells. D: CD20-negative pancreatic islet–associated B cells in untreated NOD mice convert to a CD138-positive plasma cell phenotype (right panel). B cells in PLNs were analyzed as a control (left panel). Flow cytometric profiles are shown for B220 gated cells.

Mentions: The ability of anti-CD20 treatment to block early initiating but not late stages of diabetes development in NOD mice raised the question of what effects this agent may have on B cells present in pancreatic islet leukocytic infiltrates at various points of disease pathogenesis. We initially tested whether the proportion of B cells differed within islet-associated leukocytes from 7- or 13-week-old NOD female mice at, respectively, early and late stages of diabetes development. The level of B cells was significantly greater in insulitic infiltrates of 13- than 7-week-old untreated NOD female mice (Fig. 4A). We then assessed what effect anti-CD20 treatment initiated at early or late stages of diabetes development may have on proportions of B cells within insulitic infiltrates. NOD female mice were treated with anti-CD20 at 5 or 11 weeks of age, and levels of B cells in islet-associated leukocytes evaluated 2 weeks later. While both less than in age-matched controls, levels of B cells were significantly lower in islet-associated leukocytes from 7- than 13-week-old NOD female mice treated with anti-CD20 2 weeks earlier (Fig. 4B). It is interesting that islet-associated B cells in untreated NOD mice at both 13 (Fig. 4C) and 7 weeks of age (data not shown) developed a CD20-negative phenotype, in contrast to those from PLNs. The CD20-negative phenotype was associated with islet-derived B cells in untreated NOD mice converting to a CD138-positive plasma cell–like phenotype (Fig. 4D).


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)

B cells entering pancreatic islets in NOD mice become CD20-negative plasma cells. A: Proportion of total B cells in pancreatic islet–associated leukocytes from 7- or 13-week-old untreated NOD female mice. B: Proportion of total B cells in pancreatic islet–associated leukocytes from 7- or 13-week-old NOD female mice treated 2 weeks earlier with anti-CD20. Noted statistical significance values in A and B were determined by ANOVA analyses. C: Pancreatic islet–infiltrating B cells in 13-week-old untreated NOD control mice acquire a CD20-negative phenotype (right panel). B cells in PLNs were assessed as a CD20-staining positive control (left panel). Flow cytometric profiles are shown for B220 gated cells. D: CD20-negative pancreatic islet–associated B cells in untreated NOD mice convert to a CD138-positive plasma cell phenotype (right panel). B cells in PLNs were analyzed as a control (left panel). Flow cytometric profiles are shown for B220 gated cells.
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Figure 4: B cells entering pancreatic islets in NOD mice become CD20-negative plasma cells. A: Proportion of total B cells in pancreatic islet–associated leukocytes from 7- or 13-week-old untreated NOD female mice. B: Proportion of total B cells in pancreatic islet–associated leukocytes from 7- or 13-week-old NOD female mice treated 2 weeks earlier with anti-CD20. Noted statistical significance values in A and B were determined by ANOVA analyses. C: Pancreatic islet–infiltrating B cells in 13-week-old untreated NOD control mice acquire a CD20-negative phenotype (right panel). B cells in PLNs were assessed as a CD20-staining positive control (left panel). Flow cytometric profiles are shown for B220 gated cells. D: CD20-negative pancreatic islet–associated B cells in untreated NOD mice convert to a CD138-positive plasma cell phenotype (right panel). B cells in PLNs were analyzed as a control (left panel). Flow cytometric profiles are shown for B220 gated cells.
Mentions: The ability of anti-CD20 treatment to block early initiating but not late stages of diabetes development in NOD mice raised the question of what effects this agent may have on B cells present in pancreatic islet leukocytic infiltrates at various points of disease pathogenesis. We initially tested whether the proportion of B cells differed within islet-associated leukocytes from 7- or 13-week-old NOD female mice at, respectively, early and late stages of diabetes development. The level of B cells was significantly greater in insulitic infiltrates of 13- than 7-week-old untreated NOD female mice (Fig. 4A). We then assessed what effect anti-CD20 treatment initiated at early or late stages of diabetes development may have on proportions of B cells within insulitic infiltrates. NOD female mice were treated with anti-CD20 at 5 or 11 weeks of age, and levels of B cells in islet-associated leukocytes evaluated 2 weeks later. While both less than in age-matched controls, levels of B cells were significantly lower in islet-associated leukocytes from 7- than 13-week-old NOD female mice treated with anti-CD20 2 weeks earlier (Fig. 4B). It is interesting that islet-associated B cells in untreated NOD mice at both 13 (Fig. 4C) and 7 weeks of age (data not shown) developed a CD20-negative phenotype, in contrast to those from PLNs. The CD20-negative phenotype was associated with islet-derived B cells in untreated NOD mice converting to a CD138-positive plasma cell–like phenotype (Fig. 4D).

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