Establishment of Long-Term Tolerance to SRBC in Dogs by Recombinant Canine CTLA4-Ig
| Autor: | Diane Stone, Scott S. Graves, Jeannine S. McCune, Rainer Storb, Laura J. Peterson, Marco Mielcarek, Carol Loretz |
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| Rok vydání: | 2009 |
| Předmět: |
Erythrocytes
Immunoconjugates Time Factors medicine.drug_class Recombinant Fusion Proteins chemical and pharmacologic phenomena CHO Cells Antibodies Monoclonal Humanized Transfection Monoclonal antibody Article Immune tolerance Abatacept Cricetulus Dogs CD28 Antigens Antigen Antigens CD Cricetinae Immune Tolerance medicine Animals Humans CTLA-4 Antigen Transplantation Sheep biology Antibody-Dependent Cell Cytotoxicity Hematopoietic Stem Cell Transplantation Antibodies Monoclonal Total body irradiation Molecular biology Tolerance induction Monoclonal biology.protein Lymphocyte Culture Test Mixed Antibody Immunosuppressive Agents |
| Zdroj: | Transplantation. 88:317-322 |
| ISSN: | 0041-1337 |
| DOI: | 10.1097/tp.0b013e3181ae3285 |
| Popis: | Blockade of the CD28 costimulatory molecule by recombinant human cytotoxic T lymphocyte (CTL)-associated antigen (CTLA4)-Ig or CD40-CD154 interaction with the monoclonal antibody 5C8 together with donor-specific transfusion led to enhanced engraftment in the canine model of dog leukocyte antigen (DLA)-identical marrow transplantation after 1 Gy total body irradiation. To reduce or eliminate total body irradiation conditioning regimens, we have sought to develop canine specific reagents.We have created a fusion protein of the extracellular domain of canine (c) CTLA-4 linked to the hinge-CH2-CH3 domains of canine IgG1 in a pcDNA3.1+ vector. Chinese hamster ovarian cells were cotransfected with CTLA4-Ig vector and a dihydrofolate reductase-containing vector. Stable, high producing clones were generated.Cell binding and mixed leukocyte reactions indicated no significant differences in activity between cCTLA4-Ig and human CTLA4-Ig. Mixed leukocyte reaction data indicated that combinations of cCTLA4-Ig and the monoclonal antibody 5C8 were superior in blocking H-thymidine uptake compared to either reagent alone. In dogs, the circulating half-life of cCTLA4-Ig was approximately 7 days with no immune response against the fusion protein. Finally, two injections of cCTLA4-Ig effectively tolerized two dogs against eight consecutive challenges with sheep red blood cells, given over 330 days as indicated by a complete block of IgG antibody production. Tolerance was broken in one of the two dogs when a ninth injection of sheep red blood cell was given subcutaneously in incomplete Freund's adjuvant.cCTLA4-Ig is an effective nonimmunogenic blocking reagent of the CD28 costimulatory pathway in dogs and is a promising reagent for studies of tolerance induction in hematopoietic cell transplantation in the canine model. |
| Databáze: | OpenAIRE |
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