Faculty Research 1980 - 1989
Non-germ-line elements (NGE) are present in the T cell receptor beta-chain genes isolated from the mutant mouse, motheaten (me/me).
Document Type
Article
Publication Date
1986
Keywords
Antibody-Diversity, Base-Sequence, Cloning-Molecular, DNA-Recombinant, Genes-Structural, Immunoglobulin-Variable-Region: ge, Immunoglobulins-Heavy-Chain: ge, Male, Mice, Mice-Mutant-Strains: ge, im, Receptors-Antigen-T-Cell: ge, SUPPORT-NON-U-S-GOVT, SUPPORT-U-S-GOVT-P-H-S, T-Lymphocytes: me
First Page
2697
Last Page
2700
JAX Source
J-Immunol. 1986 Apr 1; 136(7):2697-700.
Grant
AI18790, CA20408
Abstract
Extra nucleotides (which we call NGE, for non-germ-line elements) are inserted at the junctions of rearranged V, D, and J segments in the immunoglobulin heavy and T cell receptor beta-chain V region genes. NGE addition helps diversity HV3 regions of these genes. It is believed that NGE are added enzymatically and without template during the joining process. Terminal deoxynucleotidyl transferase (TdT) is thought to be the cause of NGE formation. TdT is normally detected in murine thymus and bone marrow cells, but its presence in the immunodeficient mutant mouse, Motheaten (me/me), is extremely reduced in these tissues. To determine whether this TdT deficiency could affect NGE formation during the V-D-J joining of antigen receptor genes, we cloned several rearranged T cell receptor beta-chain genes from thymocytes of me/me mice. Our sequence analysis revealed that Motheaten thymus beta-chain genes have approximately 4 base pair NGE, which are comparable in size to the NGE of wild-type genes. These results do not support the idea that TdT is the NGE-forming enzyme, although it is still possible that a low but residual level of TdT is capable of NGE formation in Motheaten. Alternatively, our data may suggest that the TdT activity in Motheaten T cells is normal; however, the number of TdT+ cells is greatly reduced in the Motheaten thymus, due to a severe defect in T cell development.
Recommended Citation
Hagiya M,
Davis DD,
Shultz LD,
Sakano H.
Non-germ-line elements (NGE) are present in the T cell receptor beta-chain genes isolated from the mutant mouse, motheaten (me/me). J-Immunol. 1986 Apr 1; 136(7):2697-700.