The structure of anti-Gal immunoglobulin genes in naïve and stimulated Gal knockout mice
| Autor: | H, Xu, A, Sharma, L, Chen, C, Harrison, Y, Wei, A S, Chong, J S, Logan, G W, Byrne, A, Shama |
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| Rok vydání: | 2001 |
| Předmět: |
Somatic cell
Molecular Sequence Data Transplantation Heterologous Cross Reactions Disaccharides Germline Epitope Antibodies Mice Reference Values Animals Gene Mice Knockout Transplantation Hybridomas biology Base Sequence Genes Immunoglobulin Molecular biology Isotype Peptide Fragments Rats Knockout mouse Immunology biology.protein Heart Transplantation Antibody |
| Zdroj: | Transplantation. 72(11) |
| ISSN: | 0041-1337 |
| Popis: | Background Naturally occurring antibodies (Nabs) that bind to terminal galactose alpha1,3-galactose carbohydrate structures (Gal) are present in humans and Old World monkeys but are negatively regulated in other mammalian species because they express Gal epitopes on their cell surfaces. A Gal knockout mouse (Gal-/-) model, generated by homologous disruption of alpha1,3-galactosyltransferase gene, is capable of producing natural anti-Gal Abs. Methods To study the genetic control of the anti-Gal response, we have generated anti-Gal hybridomas from Gal-/- mice and analyzed VH genes of anti-Gal Abs from naive animals and from mice stimulated by rat heterotopic heart transplantation. Results Six immunoglobulin (Ig)M anti-Gal hybridomas derived from naive Gal-/- mice exhibited anti-Gal binding activity with some cross-reactivity to related carbohydrate structures. These naive anti-Gal Abs used five different VH genes in a germline configuration. Anti-Gal IgM hybridomas isolated after a rat heterotopic heart xenograft (4 days) utilized germline VH gene segments from the VH7183 family and exhibited less cross-reactivity. In contrast to mice 4 days after xenograft, we have predominantly isolated IgG anti-Gal hybridomas from mice 21 days after rat heterotopic heart xenografts, indicating an isotype switch. Nine of the IgG anti-Gal hybridomas secreted IgG3 subclass and one produced IgG1. Sequence analysis of the VH gene usage from the induced anti-Gal IgG antibodies demonstrated a restricted gene utilization (VHJ606-V14A). Conclusion Our results demonstrate that the anti-Gal response in naive Gal-/- mice is encoded by multiple germline progenitors. In response to a xenograft, the induced anti-Gal Abs exhibited a restricted gene usage and somatic mutations, indicating a positive selection. |
| Databáze: | OpenAIRE |
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