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Comparing the efficacy and neuroinflammatory potential of three anti-abeta antibodies.

Fuller JP, Stavenhagen JB, Christensen S, Kartberg F, Glennie MJ, Teeling JL - Acta Neuropathol. (2015)

Bottom Line: In this study, we directly compared 3 clinical candidates in the same pre-clinical model, with the same effector function, for their ability to clear plaques and induce inflammation in the brain.This translated into 3D6 effectively clearing plaques and reducing the levels of insoluble Aβ, whilst chGantenerumab and mC2 did not. 3D6 caused a significant increase in the levels of pro-inflammatory cytokines IL-1β and TNFα, and an associated increase in microglial expression of CD11B and CD68. chGantenerumab increased pro-inflammatory cytokines and microglial activation, but minimal changes in CD68, as an indicator of phagocytosis.Injection of mC2 did not cause any significant inflammatory changes.

View Article: PubMed Central - PubMed

Affiliation: Centre for Biological Sciences, University of Southampton, Southampton, UK. jpf1g11@soton.ac.uk.

ABSTRACT
Immunotherapy is a promising strategy for the treatment of Alzheimer's disease (AD). Antibodies directed against Amyloid Beta (Aβ) are able to successfully clear plaques and reverse cognitive deficits in mouse models. Excitement towards this approach has been tempered by high profile failures in the clinic, one key issue has been the development of inflammatory side effects in the brain (ARIAs). New antibodies are entering the clinic for Alzheimer's disease; therefore, it is important to learn all we can from the current generation. In this study, we directly compared 3 clinical candidates in the same pre-clinical model, with the same effector function, for their ability to clear plaques and induce inflammation in the brain. We produced murine versions of the antibodies: Bapineuzumab (3D6), Crenezumab (mC2) and Gantenerumab (chGantenerumab) with an IgG2a constant region. 18-month transgenic APP mice (Tg2576) were injected bilaterally into the hippocampus with 2 µg of each antibody or control. After 7 days, the mice tissue was analysed for clearance of plaques and neuroinflammation by histology and biochemical analysis. 3D6 was the best binder to plaques and in vitro, whilst mC2 bound the least strongly. This translated into 3D6 effectively clearing plaques and reducing the levels of insoluble Aβ, whilst chGantenerumab and mC2 did not. 3D6 caused a significant increase in the levels of pro-inflammatory cytokines IL-1β and TNFα, and an associated increase in microglial expression of CD11B and CD68. chGantenerumab increased pro-inflammatory cytokines and microglial activation, but minimal changes in CD68, as an indicator of phagocytosis. Injection of mC2 did not cause any significant inflammatory changes. Our results demonstrate that the ability of an antibody to clear plaques and induce inflammation is dependent on the epitope and affinity of the antibody.

No MeSH data available.


Related in: MedlinePlus

Expression of microglial activation markers after antibody injection. Expression of microglial markers CD11B and CD68 and IgG distribution in the hippocampus 7 days after injection of anti-Aβ antibodies. a–h Representative images of CD11B expression. i–p Representative images of CD68. q–x Representative images of IgG distribution. y–ab No primary control sections. Pictures are taken with a 5× objective and 40× objective, scale bars 100 and 800 µm, respectively. Staining was quantified as area above threshold of staining and analysed by one-way ANOVA and Tukey post hoc test (n = 6/7). 3D6 induced a significant increase in the expression of CD11B, compared to injection with mC2 and irrelevant IgG2a (Fig. 4a–h, p = 0.0023 and p = 0.0017, respectively). chGantenerumab also induced CD11B upregulation in comparison to mC2 and irrelevant IgG2a (p = 0.0093 and p = 0.007, respectively). chGantenerumab has significantly higher levels of IgG than control injected animals (p = 0.011)
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Fig4: Expression of microglial activation markers after antibody injection. Expression of microglial markers CD11B and CD68 and IgG distribution in the hippocampus 7 days after injection of anti-Aβ antibodies. a–h Representative images of CD11B expression. i–p Representative images of CD68. q–x Representative images of IgG distribution. y–ab No primary control sections. Pictures are taken with a 5× objective and 40× objective, scale bars 100 and 800 µm, respectively. Staining was quantified as area above threshold of staining and analysed by one-way ANOVA and Tukey post hoc test (n = 6/7). 3D6 induced a significant increase in the expression of CD11B, compared to injection with mC2 and irrelevant IgG2a (Fig. 4a–h, p = 0.0023 and p = 0.0017, respectively). chGantenerumab also induced CD11B upregulation in comparison to mC2 and irrelevant IgG2a (p = 0.0093 and p = 0.007, respectively). chGantenerumab has significantly higher levels of IgG than control injected animals (p = 0.011)

Mentions: Neuroinflammation is thought to be a main cause of side effects in patients treated with anti-Aβ antibodies, therefore, we compared the ability of each of the antibody to induce inflammation after intracerebral injection. We first analysed changes in microglial phenotype by immunohistochemistry. Injection of 3D6 induced a significant increase in the expression of microglial marker CD11B, compared to injection with mC2 and irrelevant IgG2a (Fig. 4a–h, p = 0.0023 and p = 0.0017, respectively). chGantenerumab also induced CD11B upregulation in comparison to mC2 and irrelevant IgG2a (p = 0.0093 and p = 0.007, respectively). We have previously shown CD11B to be upregulated after IgG immune complex formation in the brain [27], suggesting that the increase in CD11B may be due to FcγR binding and subsequent activation of microglia. To assess phagocytic activity, we analysed expression levels of CD68 and detected an increased CD68 expression on microglia in 3D6 injected animals, but not in chGantenerumab injected animals, although the increase was not significantly different (Fig. 4i–p, p = 0.08). Figure 4q–x shows staining for mouse IgG, and there is evidence of target engagement by all three of the anti-Aβ antibodies following intracranial injection, as plaques are positive for IgG. Quantification shows that chGantenerumab has significantly higher levels of IgG than control injected animals (Fig. 4 q–x, p = 0.011). Unlike in vitro binding assays, there was no evidence of the chGantenerumab binding to neurons.Fig. 4


Comparing the efficacy and neuroinflammatory potential of three anti-abeta antibodies.

Fuller JP, Stavenhagen JB, Christensen S, Kartberg F, Glennie MJ, Teeling JL - Acta Neuropathol. (2015)

Expression of microglial activation markers after antibody injection. Expression of microglial markers CD11B and CD68 and IgG distribution in the hippocampus 7 days after injection of anti-Aβ antibodies. a–h Representative images of CD11B expression. i–p Representative images of CD68. q–x Representative images of IgG distribution. y–ab No primary control sections. Pictures are taken with a 5× objective and 40× objective, scale bars 100 and 800 µm, respectively. Staining was quantified as area above threshold of staining and analysed by one-way ANOVA and Tukey post hoc test (n = 6/7). 3D6 induced a significant increase in the expression of CD11B, compared to injection with mC2 and irrelevant IgG2a (Fig. 4a–h, p = 0.0023 and p = 0.0017, respectively). chGantenerumab also induced CD11B upregulation in comparison to mC2 and irrelevant IgG2a (p = 0.0093 and p = 0.007, respectively). chGantenerumab has significantly higher levels of IgG than control injected animals (p = 0.011)
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Fig4: Expression of microglial activation markers after antibody injection. Expression of microglial markers CD11B and CD68 and IgG distribution in the hippocampus 7 days after injection of anti-Aβ antibodies. a–h Representative images of CD11B expression. i–p Representative images of CD68. q–x Representative images of IgG distribution. y–ab No primary control sections. Pictures are taken with a 5× objective and 40× objective, scale bars 100 and 800 µm, respectively. Staining was quantified as area above threshold of staining and analysed by one-way ANOVA and Tukey post hoc test (n = 6/7). 3D6 induced a significant increase in the expression of CD11B, compared to injection with mC2 and irrelevant IgG2a (Fig. 4a–h, p = 0.0023 and p = 0.0017, respectively). chGantenerumab also induced CD11B upregulation in comparison to mC2 and irrelevant IgG2a (p = 0.0093 and p = 0.007, respectively). chGantenerumab has significantly higher levels of IgG than control injected animals (p = 0.011)
Mentions: Neuroinflammation is thought to be a main cause of side effects in patients treated with anti-Aβ antibodies, therefore, we compared the ability of each of the antibody to induce inflammation after intracerebral injection. We first analysed changes in microglial phenotype by immunohistochemistry. Injection of 3D6 induced a significant increase in the expression of microglial marker CD11B, compared to injection with mC2 and irrelevant IgG2a (Fig. 4a–h, p = 0.0023 and p = 0.0017, respectively). chGantenerumab also induced CD11B upregulation in comparison to mC2 and irrelevant IgG2a (p = 0.0093 and p = 0.007, respectively). We have previously shown CD11B to be upregulated after IgG immune complex formation in the brain [27], suggesting that the increase in CD11B may be due to FcγR binding and subsequent activation of microglia. To assess phagocytic activity, we analysed expression levels of CD68 and detected an increased CD68 expression on microglia in 3D6 injected animals, but not in chGantenerumab injected animals, although the increase was not significantly different (Fig. 4i–p, p = 0.08). Figure 4q–x shows staining for mouse IgG, and there is evidence of target engagement by all three of the anti-Aβ antibodies following intracranial injection, as plaques are positive for IgG. Quantification shows that chGantenerumab has significantly higher levels of IgG than control injected animals (Fig. 4 q–x, p = 0.011). Unlike in vitro binding assays, there was no evidence of the chGantenerumab binding to neurons.Fig. 4

Bottom Line: In this study, we directly compared 3 clinical candidates in the same pre-clinical model, with the same effector function, for their ability to clear plaques and induce inflammation in the brain.This translated into 3D6 effectively clearing plaques and reducing the levels of insoluble Aβ, whilst chGantenerumab and mC2 did not. 3D6 caused a significant increase in the levels of pro-inflammatory cytokines IL-1β and TNFα, and an associated increase in microglial expression of CD11B and CD68. chGantenerumab increased pro-inflammatory cytokines and microglial activation, but minimal changes in CD68, as an indicator of phagocytosis.Injection of mC2 did not cause any significant inflammatory changes.

View Article: PubMed Central - PubMed

Affiliation: Centre for Biological Sciences, University of Southampton, Southampton, UK. jpf1g11@soton.ac.uk.

ABSTRACT
Immunotherapy is a promising strategy for the treatment of Alzheimer's disease (AD). Antibodies directed against Amyloid Beta (Aβ) are able to successfully clear plaques and reverse cognitive deficits in mouse models. Excitement towards this approach has been tempered by high profile failures in the clinic, one key issue has been the development of inflammatory side effects in the brain (ARIAs). New antibodies are entering the clinic for Alzheimer's disease; therefore, it is important to learn all we can from the current generation. In this study, we directly compared 3 clinical candidates in the same pre-clinical model, with the same effector function, for their ability to clear plaques and induce inflammation in the brain. We produced murine versions of the antibodies: Bapineuzumab (3D6), Crenezumab (mC2) and Gantenerumab (chGantenerumab) with an IgG2a constant region. 18-month transgenic APP mice (Tg2576) were injected bilaterally into the hippocampus with 2 µg of each antibody or control. After 7 days, the mice tissue was analysed for clearance of plaques and neuroinflammation by histology and biochemical analysis. 3D6 was the best binder to plaques and in vitro, whilst mC2 bound the least strongly. This translated into 3D6 effectively clearing plaques and reducing the levels of insoluble Aβ, whilst chGantenerumab and mC2 did not. 3D6 caused a significant increase in the levels of pro-inflammatory cytokines IL-1β and TNFα, and an associated increase in microglial expression of CD11B and CD68. chGantenerumab increased pro-inflammatory cytokines and microglial activation, but minimal changes in CD68, as an indicator of phagocytosis. Injection of mC2 did not cause any significant inflammatory changes. Our results demonstrate that the ability of an antibody to clear plaques and induce inflammation is dependent on the epitope and affinity of the antibody.

No MeSH data available.


Related in: MedlinePlus