Abstract

Somatic DNA recombination plays key roles in the activation and diversification of antigen receptor genes. There are two different types of gene rearrangements in the immune system. One is V-(D)-J joining, which assembles the variable region gene segments of immunoglobulin (Ig) and T cell receptor genes. The other is class switch recombination, which replaces Ig heavy-chain constant region genes. This application aims to study the molecular mechanisms and regulation of somatic DNA recombination in lymphocytes.
Specific aims are: 1) To identify cis-acting DNA elements that negatively regulate V-(D)-J joining; 2) To characterize the V-(D)-J recombinase and its genes; and 3) To determine the DNA region regulating the class-specificity of switch recombination.
In aim 1, we will study what determines the cell-type specificity and the stage-specificity of V-(D)-J joining. We have recently found that the 3'Ckappa region may contain a cis-acting DNA element(s) that restricts Ig kappa gene rearrangement to the pre-B stage of B cell development. We will further characterize the regulatory element(s) and DNA binding proteins. Using recombination signal probes, we have isolated a CDNA clone coding for an HMG1-related DNA binding protein. Genetic backcross experiments have shown that the gene (rsb-1) is tightly linked to the recombination activating genes (rag-1 and rag-2) in mouse chromosome 2.
In aim 2, we will study the possible roles of these genes in V-(D)-J joining. Unlike V-(D)-J recombination, class switching is an antigen-dependent process. Switch recombination is directed by some cytokines in a class- specific manner.
In aim 3, we will identify DNA elements which determine the class-specificity of recombination. These studies will help our understanding of the molecular mechanisms of gene rearrangement in the context of lymphocyte development. They will also shed light on the basic processes of some immunodeficiencies and chromosome abnormalities caused by DNA arrangement.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
2R01AI018790-12
Application #
3567949
Study Section
Allergy and Immunology Study Section (ALY)
Project Start
1982-08-01
Project End
1998-08-31
Budget Start
1993-09-01
Budget End
1994-08-31
Support Year
12
Fiscal Year
1993
Total Cost
Indirect Cost

  Institution

Name
University of California Berkeley
Department
Type
DUNS #
094878337
City
Berkeley
State
CA
Country
United States
Zip Code
94704

  Publications

Usuda, S; Takemori, T; Matsuoka, M et al. (1992) Immunoglobulin V gene replacement is caused by the intramolecular DNA deletion mechanism. EMBO J 11:611-8
Davis, D D; Yoshida, K; Kingsbury, L et al. (1991) Circular DNA resulting from recombination between V-(D)-J joining signals and switch repetitive sequences in mouse thymocytes. J Exp Med 173:743-6
Matsuoka, M; Nagawa, F; Okazaki, K et al. (1991) Detection of somatic DNA recombination in the transgenic mouse brain. Science 254:81-6
Shirakata, M; Huppi, K; Usuda, S et al. (1991) HMG1-related DNA-binding protein isolated with V-(D)-J recombination signal probes. Mol Cell Biol 11:4528-36
Yoshida, K; Matsuoka, M; Usuda, S et al. (1990) Immunoglobulin switch circular DNA in the mouse infected with Nippostrongylus brasiliensis: evidence for successive class switching from mu to epsilon via gamma 1. Proc Natl Acad Sci U S A 87:7829-33
Matsuoka, M; Yoshida, K; Maeda, T et al. (1990) Switch circular DNA formed in cytokine-treated mouse splenocytes: evidence for intramolecular DNA deletion in immunoglobulin class switching. Cell 62:135-42
Okazaki, K; Sakano, H (1988) Thymocyte circular DNA excised from T cell receptor alpha-delta gene complex. EMBO J 7:1669-74
Matsuoka, M; Hagiya, M; Hattori, T et al. (1988) Gene rearrangements of T cell receptor beta and gamma chains in HTLV-I infected primary neoplastic T cells. Leukemia 2:84-90
Okazaki, K; Nishikawa, S; Sakano, H (1988) Aberrant immunoglobulin gene rearrangement in scid mouse bone marrow cells. J Immunol 141:1348-52
Okazaki, K; Davis, D D; Sakano, H (1987) T cell receptor beta gene sequences in the circular DNA of thymocyte nuclei: direct evidence for intramolecular DNA deletion in V-D-J joining. Cell 49:477-85

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