1. Elimination of murine and human T-cell epitopes in recombinant immunotoxin eliminates neutralizing and anti-drug antibodies in vivo
- Author
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Ronit Mazor, Gilad Kaplan, Devorah Crown, Ira Pastan, Youjin Jang, and Selamawit Addissie
- Subjects
0301 basic medicine ,Subdominant ,T-Lymphocytes ,Immunology ,Epitopes, T-Lymphocyte ,Lymphocyte Activation ,Epitope ,Antibodies ,law.invention ,03 medical and health sciences ,Mice ,Antigen ,In vivo ,Immunotoxin ,law ,Immunology and Allergy ,Animals ,Humans ,Mice, Inbred BALB C ,biology ,Antibodies, Monoclonal ,Virology ,Molecular biology ,Antibodies, Neutralizing ,030104 developmental biology ,Infectious Diseases ,Immunization ,Antibody Formation ,biology.protein ,Recombinant DNA ,Female ,Antibody ,Research Article - Abstract
Antibodies against the toxin portion of recombinant immunotoxins (RIT) reduce their efficacy and pose a potential safety risk. To overcome this problem we mutated the very immunogenic immunotoxin SS1P to produce LMB-T20, a de-immunized RIT that has the eight human T-cell epitopes in SS1P modified or removed. To determine the effect of T-cell epitope removal in vivo we mapped the T-cell epitopes in immune-competent BALB/c mice and found that these mice recognize two epitopes. One corresponds to the human immunodominant T-cell epitope and the other to a human subdominant epitope; both were eliminated in LMB-T20. We found that mice immunized with LMB-T20 did not have T-cell activation and did not develop anti-drug antibodies (ADA), whereas mice immunized with SS1P, showed T-cell activation, and developed ADA detected by both ELISA and drug neutralizing assays. The ability of the mice treated with LMB-T20 to respond to other antigens was not compromised. We conclude that elimination of T-cell epitopes is sufficient to prevent formation of antibodies to an immunogenic foreign protein. more...
- Published
- 2015