Specific deletion of the J-C delta locus in murine alpha/beta T cell clones and studies using transgenic mice.
A deletion event in the T cell receptor (TcR) delta locus has been characterized in a panel of mouse alpha/beta cytotoxic T lymphocyte (CTL) clones. Data presented here shows that J delta 1, J delta 2 and C delta are absent from functional CTL clones while a germ-line D delta 1 fragment is retained, thus suggesting a specific deletion of this region. We have investigated the possible significance of the J-C delta deletion by generating T cell lines from TcR alpha/beta transgenic mice. Unlike control T cell lines which included a T cell line derived from a beta transgenic mouse, the lines expressing the transgenic alpha/beta heterodimer have not deleted the C delta region. This strongly suggests that the J-C delta deletion event is not responsible for directing T cells to the alpha/beta lineage, but rather is involved in the rearrangement or transcriptional activity of the alpha locus. In addition, to ensure that the alpha/beta transgene does not have any inhibitory affects on the rearrangement of the delta loci in general, the gamma/delta expressing dendritic epithelial T cell (DETC) population was examined in TcR alpha/beta transgenic mice and alterations in this T cell subset were not found. This finding that normal gamma/delta DETC cells are present in alpha/beta transgenic mice, together with the data showing that the D delta 1 region remains in an unrearranged germ-line configuration in functional alpha/beta CTL, suggests that commitment to the alpha/beta or gamma/delta lineage is predetermined at a particular stage in early T cell ontogeny.
Ohashi
P S
PS
Department of Experimental Pathology, University Hospital, Zürich, Switzerland.
Wallace
V A
VA
Broughton
H
H
Ohashi
C T
CT
Ferrick
D A
DA
Jost
V
V
Mak
T W
TW
Hengartner
H
H
Pircher
H
H
D000818:Animals; D015139:Blotting, Southern; D002454:Cell Differentiation; D002460:Cell Line; D002872:Chromosome Deletion; D015329:Gene Rearrangement, T-Lymphocyte; D051379:Mice; D008822:Mice, Transgenic; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D013602:T-Lymphocytes, Cytotoxic / Q000502:physiology*
D011948:Receptors, Antigen, T-Cell