T cell migration during development: homing is not related to TCR V beta 1 repertoire selection.
T cell precursors enter the chick thymus in three waves during embryonic life. Each wave of thymocyte precursors colonizing the thymus gave rise to a similar TCR V beta repertoire in thymus, spleen and intestine both in terms of V beta 1 and J beta usage as well as in the length of V beta-D beta-J beta junctions. Seventeen V beta 1s were utilized, and a new J beta segment was found. In the progeny of the third wave, more nucleotides were deleted at the 5' end of the J beta segment, but the overall size of the CDR3 was conserved by a concomitant increase of N nucleotide addition at the V beta-D beta-J beta junctions during rearrangement. This CDR3 modification was observed in the spleen but not in the intestine, implying that progeny of the third wave migrate preferentially to the spleen, a possibility that was confirmed by adoptive cell transfers into congenic chickens. Very low frequencies of non-productive rearrangements in the intestine suggested that negative selection may occur in this organ. The present analysis indicates that V beta 1+ T cells in spleen and intestine are primarily of thymic origin, this colonization of both organs occurs in waves and is not characterized by preselection of the TCR V beta 1 repertoire.
Dunon
D
D
Basel Institute for Immunology, Switzerland.
Schwager
J
J
Dangy
J P
JP
Cooper
M D
MD
Imhof
B A
BA
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002465:Cell Movement; D002642:Chick Embryo; D018076:DNA, Complementary; D006411:Hematopoiesis, Extramedullary; D007421:Intestine, Small / Q000166:cytology / Q000196:embryology; D008969:Molecular Sequence Data; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology* / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000196:embryology
D018076:DNA, Complementary; D016693:Receptors, Antigen, T-Cell, alpha-beta