Repertoires of antigen receptors in Tdt congenitally deficient mice.
Tdt deficient mice show lack of N region in V(D)J junctions of immunoglobulin and T cell receptor genes and revealed that "immature recombinase" in fetal stage would boil down to no more than a lack of Tdt. Although particular junctions which are thought to be created by homology-mediated joining are frequently observed, one fourth of junctions lacked even one bp of overlap, indicating the existence of a V(D)J joining pathway that is homology independent. Lymphocyte repertoire which express VH81X gene without N region is negatively selected, which shows that the repertoire of Tdt deficient mice is not a truly fetal repertoire. Positive selection of thymocytes is more efficient in Tdt deficient mice. Furthermore Tdt-/- mice produce significant amounts of anti-dsDNA antibodies as Tdt+/+ mice, indicating that increased diversity of the third complementarity-determining region (CDR3) by Tdt is not essential for the expansion of precursor B cells programmed to produce anti-DNA antibodies.
Komori
T
T
Department of Medicine III, Osaka University Medical School, Japan.
Pricop
L
L
Hatakeyama
A
A
Bona
C A
CA
Alt
F W
FW
D000818:Animals; D001323:Autoantibodies / Q000096:biosynthesis; D004253:DNA Nucleotidylexotransferase / Q000172:deficiency*; D051379:Mice; D011948:Receptors, Antigen, T-Cell / Q000235:genetics; D013601:T-Lymphocytes / Q000502:physiology*
D001323:Autoantibodies; D011948:Receptors, Antigen, T-Cell; D004253:DNA Nucleotidylexotransferase