Limits...
Prevention of experimental autoimmune myasthenia gravis by rat Crry-Ig: A model agent for long-term complement inhibition in vivo.

Hepburn NJ, Chamberlain-Banoub JL, Williams AS, Morgan BP, Harris CL - Mol. Immunol. (2007)

Bottom Line: Fusion of these domains to rat IgG2a Fc generated an effective complement inhibitor (rCrry-Ig) with a circulating half-life prolonged from 7 min for Crry alone to 53 h for rCrry-Ig.Systemic administration of rCrry-Ig over 5 weeks generated a weak immune response to the recombinant agent, however this was predominantly IgM in nature and did not neutralise Crry function or cause clearance of the agent from plasma.The long half-life and low immunogenicity of this agent will be useful for therapy in chronic models of inflammatory disease in the rat.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, United Kingdom.

ABSTRACT
Despite its vital role in innate immunity, complement is involved in a number of inflammatory pathologies and has therefore become a therapeutic target. Most agents generated for anti-complement therapy have short half-lives in plasma, or have been of mouse or human origin, thereby limiting their use either to murine models of disease or to short-term therapy. Here we describe the generation of a long-acting rat therapeutic agent based on the rat complement inhibitor, Crry. Characterisation of various soluble forms of Crry demonstrated that the amino-terminal four short-consensus repeat domains were required for full regulatory and C3b-binding activities. Fusion of these domains to rat IgG2a Fc generated an effective complement inhibitor (rCrry-Ig) with a circulating half-life prolonged from 7 min for Crry alone to 53 h for rCrry-Ig. Systemic administration of rCrry-Ig over 5 weeks generated a weak immune response to the recombinant agent, however this was predominantly IgM in nature and did not neutralise Crry function or cause clearance of the agent from plasma. Administration of rCrry-Ig completely abrogated clinical disease in a rat model of myasthenia gravis whereas soluble Crry lacking the immunoglobulin Fc domain caused a partial response. rCrry-Ig not only ablated clinical disease, but also prevented C3 and C9 deposition at the neuromuscular junction and inhibited cellular infiltration at this site. The long half-life and low immunogenicity of this agent will be useful for therapy in chronic models of inflammatory disease in the rat.

Show MeSH

Related in: MedlinePlus

Clinical assessment of rats with EAMG. EAMG was induced in rats and weight change (a) and clinical score (b) were monitored. Control animals (●) rapidly developed a clinical score and lost weight, these animals were sacrificed at 52 h and thereafter their score was scored 4. rCrry-Ig-treated animals (▴) were protected from disease whilst sCrry-treated animals (■) developed slight clinical disease and then recovered.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2572221&req=5

fig7: Clinical assessment of rats with EAMG. EAMG was induced in rats and weight change (a) and clinical score (b) were monitored. Control animals (●) rapidly developed a clinical score and lost weight, these animals were sacrificed at 52 h and thereafter their score was scored 4. rCrry-Ig-treated animals (▴) were protected from disease whilst sCrry-treated animals (■) developed slight clinical disease and then recovered.

Mentions: The therapeutic effect of rCrry-Ig and sCrry was assessed in a rat model of EAMG. Untreated animals rapidly developed severe weight loss and paralysis and had to be sacrificed by 52 h. Therapy with rCrry-Ig prevented weight loss (Fig. 7a) and totally ablated clinical disease (Fig. 7b). Animals treated with sCrry had mild disease with weight loss and an increasing clinical score until 52 h post-induction when they began to recover; clinical disease was always less severe than in control animals. Immunohistochemical analysis at the end plate demonstrated significantly reduced C3 and C9 deposition in the rCrry-Ig animals compared to the control and sCrry animals (Fig. 8; Table 2). Immunohistochemical analysis and H&E staining demonstrated reduced levels of cellular infiltration in the rCrry-Ig-treated animals (Table 2).


Prevention of experimental autoimmune myasthenia gravis by rat Crry-Ig: A model agent for long-term complement inhibition in vivo.

Hepburn NJ, Chamberlain-Banoub JL, Williams AS, Morgan BP, Harris CL - Mol. Immunol. (2007)

Clinical assessment of rats with EAMG. EAMG was induced in rats and weight change (a) and clinical score (b) were monitored. Control animals (●) rapidly developed a clinical score and lost weight, these animals were sacrificed at 52 h and thereafter their score was scored 4. rCrry-Ig-treated animals (▴) were protected from disease whilst sCrry-treated animals (■) developed slight clinical disease and then recovered.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2572221&req=5

fig7: Clinical assessment of rats with EAMG. EAMG was induced in rats and weight change (a) and clinical score (b) were monitored. Control animals (●) rapidly developed a clinical score and lost weight, these animals were sacrificed at 52 h and thereafter their score was scored 4. rCrry-Ig-treated animals (▴) were protected from disease whilst sCrry-treated animals (■) developed slight clinical disease and then recovered.
Mentions: The therapeutic effect of rCrry-Ig and sCrry was assessed in a rat model of EAMG. Untreated animals rapidly developed severe weight loss and paralysis and had to be sacrificed by 52 h. Therapy with rCrry-Ig prevented weight loss (Fig. 7a) and totally ablated clinical disease (Fig. 7b). Animals treated with sCrry had mild disease with weight loss and an increasing clinical score until 52 h post-induction when they began to recover; clinical disease was always less severe than in control animals. Immunohistochemical analysis at the end plate demonstrated significantly reduced C3 and C9 deposition in the rCrry-Ig animals compared to the control and sCrry animals (Fig. 8; Table 2). Immunohistochemical analysis and H&E staining demonstrated reduced levels of cellular infiltration in the rCrry-Ig-treated animals (Table 2).

Bottom Line: Fusion of these domains to rat IgG2a Fc generated an effective complement inhibitor (rCrry-Ig) with a circulating half-life prolonged from 7 min for Crry alone to 53 h for rCrry-Ig.Systemic administration of rCrry-Ig over 5 weeks generated a weak immune response to the recombinant agent, however this was predominantly IgM in nature and did not neutralise Crry function or cause clearance of the agent from plasma.The long half-life and low immunogenicity of this agent will be useful for therapy in chronic models of inflammatory disease in the rat.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, United Kingdom.

ABSTRACT
Despite its vital role in innate immunity, complement is involved in a number of inflammatory pathologies and has therefore become a therapeutic target. Most agents generated for anti-complement therapy have short half-lives in plasma, or have been of mouse or human origin, thereby limiting their use either to murine models of disease or to short-term therapy. Here we describe the generation of a long-acting rat therapeutic agent based on the rat complement inhibitor, Crry. Characterisation of various soluble forms of Crry demonstrated that the amino-terminal four short-consensus repeat domains were required for full regulatory and C3b-binding activities. Fusion of these domains to rat IgG2a Fc generated an effective complement inhibitor (rCrry-Ig) with a circulating half-life prolonged from 7 min for Crry alone to 53 h for rCrry-Ig. Systemic administration of rCrry-Ig over 5 weeks generated a weak immune response to the recombinant agent, however this was predominantly IgM in nature and did not neutralise Crry function or cause clearance of the agent from plasma. Administration of rCrry-Ig completely abrogated clinical disease in a rat model of myasthenia gravis whereas soluble Crry lacking the immunoglobulin Fc domain caused a partial response. rCrry-Ig not only ablated clinical disease, but also prevented C3 and C9 deposition at the neuromuscular junction and inhibited cellular infiltration at this site. The long half-life and low immunogenicity of this agent will be useful for therapy in chronic models of inflammatory disease in the rat.

Show MeSH
Related in: MedlinePlus