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Negative regulation of autoimmune demyelination by the inhibitory receptor CLM-1.

Xi H, Katschke KJ, Helmy KY, Wark PA, Kljavin N, Clark H, Eastham-Anderson J, Shek T, Roose-Girma M, Ghilardi N, van Lookeren Campagne M - J. Exp. Med. (2009)

Bottom Line: CLM-1 is expressed on inflammatory myeloid cells present in demyelinating areas of the spinal cord after immunization of mice with MOG35-55 (myelin oligodendrocyte glycoprotein) peptide.Absence of CLM-1 resulted in significantly increased nitric oxide and proinflammatory cytokine production, along with increased demyelination and worsened clinical scores, whereas T cell responses in the periphery or in the spinal cord remained unaffected.This study thus identifies CLM-1 as a negative regulator of myeloid effector cells in autoimmune demyelination.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Immunology, Genentech Inc., South San Francisco, CA 94080, USA.

ABSTRACT
Multiple sclerosis and its preclinical model, experimental autoimmune encephalomyelitis, are marked by perivascular inflammation and demyelination. Myeloid cells, derived from circulating progenitors, are a prominent component of the inflammatory infiltrate and are believed to directly contribute to demyelination and axonal damage. How the cytotoxic activity of these myeloid cells is regulated is poorly understood. We identify CMRF-35-like molecule-1 (CLM-1) as a negative regulator of autoimmune demyelination. CLM-1 is expressed on inflammatory myeloid cells present in demyelinating areas of the spinal cord after immunization of mice with MOG35-55 (myelin oligodendrocyte glycoprotein) peptide. Absence of CLM-1 resulted in significantly increased nitric oxide and proinflammatory cytokine production, along with increased demyelination and worsened clinical scores, whereas T cell responses in the periphery or in the spinal cord remained unaffected. This study thus identifies CLM-1 as a negative regulator of myeloid effector cells in autoimmune demyelination.

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Lack of CLM-1 results in increased release of myeloid-specific inflammatory mediators and exacerbated demyelination. (A) Production of Th1, Th17, and myeloid cell–specific cytokines by leukocytes isolated from spinal cord 15 d after immunization. (B) CLM-1–positive cells apposed to MOG-positive myelin in the dorsal funiculus of the thoracic spinal cord on day 15 after immunization. (C) MOG and CD11c staining in the dorsal funiculus of the thoracic spinal cord on day15 after immunization. The lines delineate the area of demyelination. (D) Quantification of demyelinated regions in CLM-1 WT and KO mice. (E) Quantification of infiltrating leukocytes in the spinal cords of WT and KO mice 15 d after MOG immunization. Values in E are expressed as means ± SEM of six mice per group. Each symbol represents one individual mouse (A [top row] and D) or a pool of two to three mice (A, bottom row). Experiments were repeated twice (A–D) or three times (E) with at least six mice per group. n.s., not significant. *, P < 0.05; **, P < 0.01. Bars: (B) 10 µm; (C) 50 µm.
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fig5: Lack of CLM-1 results in increased release of myeloid-specific inflammatory mediators and exacerbated demyelination. (A) Production of Th1, Th17, and myeloid cell–specific cytokines by leukocytes isolated from spinal cord 15 d after immunization. (B) CLM-1–positive cells apposed to MOG-positive myelin in the dorsal funiculus of the thoracic spinal cord on day 15 after immunization. (C) MOG and CD11c staining in the dorsal funiculus of the thoracic spinal cord on day15 after immunization. The lines delineate the area of demyelination. (D) Quantification of demyelinated regions in CLM-1 WT and KO mice. (E) Quantification of infiltrating leukocytes in the spinal cords of WT and KO mice 15 d after MOG immunization. Values in E are expressed as means ± SEM of six mice per group. Each symbol represents one individual mouse (A [top row] and D) or a pool of two to three mice (A, bottom row). Experiments were repeated twice (A–D) or three times (E) with at least six mice per group. n.s., not significant. *, P < 0.05; **, P < 0.01. Bars: (B) 10 µm; (C) 50 µm.

Mentions: Next, we determined whether CLM-1 influenced reactivation of CNS-infiltrating CD4+ T cells. Spinal cord leukocytes harvested from CLM-1 WT and KO mice at the peak of disease and restimulated with MOG35-55 showed similar polarization toward Th1, Th17, and Foxp3+ T reg cells and similar T cell–specific cytokine responses (Fig. 5 A, top row; and Fig. S4 G). In contrast, leukocytes harvested from spinal cords of CLM-1 KO mice produced significantly elevated levels of nitric oxide and myeloid-specific proinflammatory cytokines as compared with WT mice (Fig. 5 A, bottom row). Thus, CLM-1 negatively regulates local myeloid effector function in the CNS without affecting T cell responses. Because microglia do not express CLM-1 and iNOS, and given the relatively small (∼10%) contribution of microglia to the total myeloid cell population harvested from the CNS at day 15 after MOG immunization, it seems likely that the increased NO2− and myeloid proinflammatory cytokine production is contributed by the infiltrating myeloid cells and not by microglia.


Negative regulation of autoimmune demyelination by the inhibitory receptor CLM-1.

Xi H, Katschke KJ, Helmy KY, Wark PA, Kljavin N, Clark H, Eastham-Anderson J, Shek T, Roose-Girma M, Ghilardi N, van Lookeren Campagne M - J. Exp. Med. (2009)

Lack of CLM-1 results in increased release of myeloid-specific inflammatory mediators and exacerbated demyelination. (A) Production of Th1, Th17, and myeloid cell–specific cytokines by leukocytes isolated from spinal cord 15 d after immunization. (B) CLM-1–positive cells apposed to MOG-positive myelin in the dorsal funiculus of the thoracic spinal cord on day 15 after immunization. (C) MOG and CD11c staining in the dorsal funiculus of the thoracic spinal cord on day15 after immunization. The lines delineate the area of demyelination. (D) Quantification of demyelinated regions in CLM-1 WT and KO mice. (E) Quantification of infiltrating leukocytes in the spinal cords of WT and KO mice 15 d after MOG immunization. Values in E are expressed as means ± SEM of six mice per group. Each symbol represents one individual mouse (A [top row] and D) or a pool of two to three mice (A, bottom row). Experiments were repeated twice (A–D) or three times (E) with at least six mice per group. n.s., not significant. *, P < 0.05; **, P < 0.01. Bars: (B) 10 µm; (C) 50 µm.
© Copyright Policy - openaccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2812551&req=5

fig5: Lack of CLM-1 results in increased release of myeloid-specific inflammatory mediators and exacerbated demyelination. (A) Production of Th1, Th17, and myeloid cell–specific cytokines by leukocytes isolated from spinal cord 15 d after immunization. (B) CLM-1–positive cells apposed to MOG-positive myelin in the dorsal funiculus of the thoracic spinal cord on day 15 after immunization. (C) MOG and CD11c staining in the dorsal funiculus of the thoracic spinal cord on day15 after immunization. The lines delineate the area of demyelination. (D) Quantification of demyelinated regions in CLM-1 WT and KO mice. (E) Quantification of infiltrating leukocytes in the spinal cords of WT and KO mice 15 d after MOG immunization. Values in E are expressed as means ± SEM of six mice per group. Each symbol represents one individual mouse (A [top row] and D) or a pool of two to three mice (A, bottom row). Experiments were repeated twice (A–D) or three times (E) with at least six mice per group. n.s., not significant. *, P < 0.05; **, P < 0.01. Bars: (B) 10 µm; (C) 50 µm.
Mentions: Next, we determined whether CLM-1 influenced reactivation of CNS-infiltrating CD4+ T cells. Spinal cord leukocytes harvested from CLM-1 WT and KO mice at the peak of disease and restimulated with MOG35-55 showed similar polarization toward Th1, Th17, and Foxp3+ T reg cells and similar T cell–specific cytokine responses (Fig. 5 A, top row; and Fig. S4 G). In contrast, leukocytes harvested from spinal cords of CLM-1 KO mice produced significantly elevated levels of nitric oxide and myeloid-specific proinflammatory cytokines as compared with WT mice (Fig. 5 A, bottom row). Thus, CLM-1 negatively regulates local myeloid effector function in the CNS without affecting T cell responses. Because microglia do not express CLM-1 and iNOS, and given the relatively small (∼10%) contribution of microglia to the total myeloid cell population harvested from the CNS at day 15 after MOG immunization, it seems likely that the increased NO2− and myeloid proinflammatory cytokine production is contributed by the infiltrating myeloid cells and not by microglia.

Bottom Line: CLM-1 is expressed on inflammatory myeloid cells present in demyelinating areas of the spinal cord after immunization of mice with MOG35-55 (myelin oligodendrocyte glycoprotein) peptide.Absence of CLM-1 resulted in significantly increased nitric oxide and proinflammatory cytokine production, along with increased demyelination and worsened clinical scores, whereas T cell responses in the periphery or in the spinal cord remained unaffected.This study thus identifies CLM-1 as a negative regulator of myeloid effector cells in autoimmune demyelination.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Immunology, Genentech Inc., South San Francisco, CA 94080, USA.

ABSTRACT
Multiple sclerosis and its preclinical model, experimental autoimmune encephalomyelitis, are marked by perivascular inflammation and demyelination. Myeloid cells, derived from circulating progenitors, are a prominent component of the inflammatory infiltrate and are believed to directly contribute to demyelination and axonal damage. How the cytotoxic activity of these myeloid cells is regulated is poorly understood. We identify CMRF-35-like molecule-1 (CLM-1) as a negative regulator of autoimmune demyelination. CLM-1 is expressed on inflammatory myeloid cells present in demyelinating areas of the spinal cord after immunization of mice with MOG35-55 (myelin oligodendrocyte glycoprotein) peptide. Absence of CLM-1 resulted in significantly increased nitric oxide and proinflammatory cytokine production, along with increased demyelination and worsened clinical scores, whereas T cell responses in the periphery or in the spinal cord remained unaffected. This study thus identifies CLM-1 as a negative regulator of myeloid effector cells in autoimmune demyelination.

Show MeSH
Related in: MedlinePlus