Limits...
Inhibition of Th17 cells regulates autoimmune diabetes in NOD mice.

Emamaullee JA, Davis J, Merani S, Toso C, Elliott JF, Thiesen A, Shapiro AM - Diabetes (2009)

Bottom Line: Insulitis scoring and immunofluorescence staining revealed that both anti-IL-17 and IL-25 significantly reduced peri-islet T-cell infiltrates.GAD65-specific ELISpot and CD4-positive adoptive transfer studies showed that IL-25 treatment resulted in a T-cell-mediated dominant protective effect against autoimmunity.Further development of Th17-targeted therapeutic agents may be of benefit in this disease.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, University of Alberta, Edmonton, Alberta,Canada. juliete@ualberta.ca

ABSTRACT

Objective: The T helper 17 (Th17) population, a subset of CD4-positive T-cells that secrete interleukin (IL)-17, has been implicated in autoimmune diseases, including multiple sclerosis and lupus. Therapeutic agents that target the Th17 effector molecule IL-17 or directly inhibit the Th17 population (IL-25) have shown promise in animal models of autoimmunity. The role of Th17 cells in type 1 diabetes has been less clear. The effect of neutralizing anti-IL-17 and recombinant IL-25 on the development of diabetes in NOD mice, a model of spontaneous autoimmune diabetes, was investigated in this study.

Research design and methods and results: Although treatment with either anti-IL-17 or IL-25 had no effect on diabetes development in young (<5 weeks) NOD mice, either intervention prevented diabetes when treatment was started at 10 weeks of age (P < 0.001). Insulitis scoring and immunofluorescence staining revealed that both anti-IL-17 and IL-25 significantly reduced peri-islet T-cell infiltrates. Both treatments also decreased GAD65 autoantibody levels. Analysis of pancreatic lymph nodes revealed that both treatments increased the frequency of regulatory T-cells. Further investigation demonstrated that IL-25 therapy was superior to anti-IL-17 during mature diabetes because it promoted a period of remission from new-onset diabetes in 90% of treated animals. Similarly, IL-25 delayed recurrent autoimmunity after syngeneic islet transplantation, whereas anti-IL-17 was of no benefit. GAD65-specific ELISpot and CD4-positive adoptive transfer studies showed that IL-25 treatment resulted in a T-cell-mediated dominant protective effect against autoimmunity.

Conclusions: These studies suggest that Th17 cells are involved in the pathogenesis of autoimmune diabetes. Further development of Th17-targeted therapeutic agents may be of benefit in this disease.

Show MeSH

Related in: MedlinePlus

Treatment with anti–IL-17 or IL-25 reduced the degree of peri-islet T-cell infiltration and was associated with an increase in the frequency of Foxp3-positive cells. Pancreata were collected from anti–IL-17–treated, IL-25–treated, and control animals 1 month after the completion of treatment. Tissue sections were stained for either CD4, CD8, Foxp3, or IL-17 (each in green) in combination with insulin (red) and nuclei (4′,6-diamidino-2-phenylindole in blue). Treatment with either anti–IL-17 or IL-25 reduced the frequency of both CD4- and CD8-positive T-cells and increased the number of Foxp3-positive Treg cells in the peri-islet infiltrate compared with controls. IL-17–positive staining was only visible in a small proportion of cells present within the insulitic lesion in control animals, and this frequency was further reduced after treatment with anti–IL-17 or IL-25. CD4, CD8, and Foxp3 staining was completed on cryosections, whereas IL-17 staining was completed on fixed sections, resulting in a difference in appearance on photography. Pancreata harvested from n = 6–8 normoglycemic animals from each treatment group were analyzed, and representative sections from each combination of staining are shown at ×200 magnification. (A high-quality digital representation of this figure is available in the online issue.)
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2682686&req=5

Figure 3: Treatment with anti–IL-17 or IL-25 reduced the degree of peri-islet T-cell infiltration and was associated with an increase in the frequency of Foxp3-positive cells. Pancreata were collected from anti–IL-17–treated, IL-25–treated, and control animals 1 month after the completion of treatment. Tissue sections were stained for either CD4, CD8, Foxp3, or IL-17 (each in green) in combination with insulin (red) and nuclei (4′,6-diamidino-2-phenylindole in blue). Treatment with either anti–IL-17 or IL-25 reduced the frequency of both CD4- and CD8-positive T-cells and increased the number of Foxp3-positive Treg cells in the peri-islet infiltrate compared with controls. IL-17–positive staining was only visible in a small proportion of cells present within the insulitic lesion in control animals, and this frequency was further reduced after treatment with anti–IL-17 or IL-25. CD4, CD8, and Foxp3 staining was completed on cryosections, whereas IL-17 staining was completed on fixed sections, resulting in a difference in appearance on photography. Pancreata harvested from n = 6–8 normoglycemic animals from each treatment group were analyzed, and representative sections from each combination of staining are shown at ×200 magnification. (A high-quality digital representation of this figure is available in the online issue.)

Mentions: To further understand the mechanism of diabetes prevention using anti–IL-17 or IL-25 treatment during the effector phase of type 1 diabetes development, detailed histological analysis was carried out in normoglycemic animals 1 month after the completion of treatment (serial sections from six to eight animals per group). Insulitis scoring by a pathologist using blinded samples indicated that both treatment strategies significantly reduced the degree of islet inflammation (Fig. 2). The majority of the pancreata in normoglycemic control animals had destructive insulitis (mean score of 2.6 ± 0.3), whereas insulitis was significantly reduced in both anti–IL-17–treated (mean score 2.0 ± 0.3) and IL-25–treated animals (1.5 ± 0.3; P < 0.05 for anti–IL-17, and P < 0.02 for IL-25 vs. controls; representative hematoxylin and eosin–stained sections from each cohort are shown inFig. 2B–D). To determine the contribution of different T-cell populations within the peri-islet infiltrates in both anti–IL-17– and IL-25–treated animals, immunofluorescence staining for CD4, CD8, Foxp3, and IL-17 was carried out in combination with insulin staining and compared with control animals. As shown inFig. 3, insulitic lesions in normoglycemic control NOD mice were composed primarily of CD4-positive cells, with a smaller proportion of CD8-positive lymphocytes and low Foxp3 staining. Examination of multiple sections of control NOD pancreata for IL-17 staining consistently showed a small number of IL-17–positive cells within the peri-islet infiltrates, regardless of the degree of insulitis. Pancreatic sections from normoglycemic animals treated with either anti–IL-17 or IL-25 demonstrated a reduced level of insulitis that was composed primarily of CD4-positive cells, a reducednumber of CD8-positive cells, and enrichment in Foxp3-positive cells compared with control animals. Very few IL-17–positive cells were observed in anti–IL-17–treated animals, with only a small proportion of inflamed islets staining positive for IL-17 (representative sections inFig. 3). Analysis of multiple sections from IL-25–treated animals for IL-17 staining did not reveal any IL-17–positive cells (representative section inFig. 3). Overall, these data indicate that inhibition of Th17 cells with both anti–IL-17 and IL-25 treatment regimens significantly reduces islet-specific inflammatory T-cell infiltration and increases the proportion of Foxp3-positive cells around the islets.


Inhibition of Th17 cells regulates autoimmune diabetes in NOD mice.

Emamaullee JA, Davis J, Merani S, Toso C, Elliott JF, Thiesen A, Shapiro AM - Diabetes (2009)

Treatment with anti–IL-17 or IL-25 reduced the degree of peri-islet T-cell infiltration and was associated with an increase in the frequency of Foxp3-positive cells. Pancreata were collected from anti–IL-17–treated, IL-25–treated, and control animals 1 month after the completion of treatment. Tissue sections were stained for either CD4, CD8, Foxp3, or IL-17 (each in green) in combination with insulin (red) and nuclei (4′,6-diamidino-2-phenylindole in blue). Treatment with either anti–IL-17 or IL-25 reduced the frequency of both CD4- and CD8-positive T-cells and increased the number of Foxp3-positive Treg cells in the peri-islet infiltrate compared with controls. IL-17–positive staining was only visible in a small proportion of cells present within the insulitic lesion in control animals, and this frequency was further reduced after treatment with anti–IL-17 or IL-25. CD4, CD8, and Foxp3 staining was completed on cryosections, whereas IL-17 staining was completed on fixed sections, resulting in a difference in appearance on photography. Pancreata harvested from n = 6–8 normoglycemic animals from each treatment group were analyzed, and representative sections from each combination of staining are shown at ×200 magnification. (A high-quality digital representation of this figure is available in the online issue.)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2682686&req=5

Figure 3: Treatment with anti–IL-17 or IL-25 reduced the degree of peri-islet T-cell infiltration and was associated with an increase in the frequency of Foxp3-positive cells. Pancreata were collected from anti–IL-17–treated, IL-25–treated, and control animals 1 month after the completion of treatment. Tissue sections were stained for either CD4, CD8, Foxp3, or IL-17 (each in green) in combination with insulin (red) and nuclei (4′,6-diamidino-2-phenylindole in blue). Treatment with either anti–IL-17 or IL-25 reduced the frequency of both CD4- and CD8-positive T-cells and increased the number of Foxp3-positive Treg cells in the peri-islet infiltrate compared with controls. IL-17–positive staining was only visible in a small proportion of cells present within the insulitic lesion in control animals, and this frequency was further reduced after treatment with anti–IL-17 or IL-25. CD4, CD8, and Foxp3 staining was completed on cryosections, whereas IL-17 staining was completed on fixed sections, resulting in a difference in appearance on photography. Pancreata harvested from n = 6–8 normoglycemic animals from each treatment group were analyzed, and representative sections from each combination of staining are shown at ×200 magnification. (A high-quality digital representation of this figure is available in the online issue.)
Mentions: To further understand the mechanism of diabetes prevention using anti–IL-17 or IL-25 treatment during the effector phase of type 1 diabetes development, detailed histological analysis was carried out in normoglycemic animals 1 month after the completion of treatment (serial sections from six to eight animals per group). Insulitis scoring by a pathologist using blinded samples indicated that both treatment strategies significantly reduced the degree of islet inflammation (Fig. 2). The majority of the pancreata in normoglycemic control animals had destructive insulitis (mean score of 2.6 ± 0.3), whereas insulitis was significantly reduced in both anti–IL-17–treated (mean score 2.0 ± 0.3) and IL-25–treated animals (1.5 ± 0.3; P < 0.05 for anti–IL-17, and P < 0.02 for IL-25 vs. controls; representative hematoxylin and eosin–stained sections from each cohort are shown inFig. 2B–D). To determine the contribution of different T-cell populations within the peri-islet infiltrates in both anti–IL-17– and IL-25–treated animals, immunofluorescence staining for CD4, CD8, Foxp3, and IL-17 was carried out in combination with insulin staining and compared with control animals. As shown inFig. 3, insulitic lesions in normoglycemic control NOD mice were composed primarily of CD4-positive cells, with a smaller proportion of CD8-positive lymphocytes and low Foxp3 staining. Examination of multiple sections of control NOD pancreata for IL-17 staining consistently showed a small number of IL-17–positive cells within the peri-islet infiltrates, regardless of the degree of insulitis. Pancreatic sections from normoglycemic animals treated with either anti–IL-17 or IL-25 demonstrated a reduced level of insulitis that was composed primarily of CD4-positive cells, a reducednumber of CD8-positive cells, and enrichment in Foxp3-positive cells compared with control animals. Very few IL-17–positive cells were observed in anti–IL-17–treated animals, with only a small proportion of inflamed islets staining positive for IL-17 (representative sections inFig. 3). Analysis of multiple sections from IL-25–treated animals for IL-17 staining did not reveal any IL-17–positive cells (representative section inFig. 3). Overall, these data indicate that inhibition of Th17 cells with both anti–IL-17 and IL-25 treatment regimens significantly reduces islet-specific inflammatory T-cell infiltration and increases the proportion of Foxp3-positive cells around the islets.

Bottom Line: Insulitis scoring and immunofluorescence staining revealed that both anti-IL-17 and IL-25 significantly reduced peri-islet T-cell infiltrates.GAD65-specific ELISpot and CD4-positive adoptive transfer studies showed that IL-25 treatment resulted in a T-cell-mediated dominant protective effect against autoimmunity.Further development of Th17-targeted therapeutic agents may be of benefit in this disease.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, University of Alberta, Edmonton, Alberta,Canada. juliete@ualberta.ca

ABSTRACT

Objective: The T helper 17 (Th17) population, a subset of CD4-positive T-cells that secrete interleukin (IL)-17, has been implicated in autoimmune diseases, including multiple sclerosis and lupus. Therapeutic agents that target the Th17 effector molecule IL-17 or directly inhibit the Th17 population (IL-25) have shown promise in animal models of autoimmunity. The role of Th17 cells in type 1 diabetes has been less clear. The effect of neutralizing anti-IL-17 and recombinant IL-25 on the development of diabetes in NOD mice, a model of spontaneous autoimmune diabetes, was investigated in this study.

Research design and methods and results: Although treatment with either anti-IL-17 or IL-25 had no effect on diabetes development in young (<5 weeks) NOD mice, either intervention prevented diabetes when treatment was started at 10 weeks of age (P < 0.001). Insulitis scoring and immunofluorescence staining revealed that both anti-IL-17 and IL-25 significantly reduced peri-islet T-cell infiltrates. Both treatments also decreased GAD65 autoantibody levels. Analysis of pancreatic lymph nodes revealed that both treatments increased the frequency of regulatory T-cells. Further investigation demonstrated that IL-25 therapy was superior to anti-IL-17 during mature diabetes because it promoted a period of remission from new-onset diabetes in 90% of treated animals. Similarly, IL-25 delayed recurrent autoimmunity after syngeneic islet transplantation, whereas anti-IL-17 was of no benefit. GAD65-specific ELISpot and CD4-positive adoptive transfer studies showed that IL-25 treatment resulted in a T-cell-mediated dominant protective effect against autoimmunity.

Conclusions: These studies suggest that Th17 cells are involved in the pathogenesis of autoimmune diabetes. Further development of Th17-targeted therapeutic agents may be of benefit in this disease.

Show MeSH
Related in: MedlinePlus