THE TCR-DELTA REPERTOIRE IN HUMAN INTESTINE UNDERGOES CHARACTERISTIC CHANGES DURING FETAL TO ADULT DEVELOPMENT

The TCR-delta repertoire in adult human intestine is oligoclonal and u nique in each individual, In the present study, changes in the junctio nal regions of TCR-delta transcripts in human intestine that occur dur ing development from fetal to adult life were used to characterize fun damental changes in the TCR-delta repertoire in the human intestinal t ract during ontogeny, At mid-gestation, the fetal repertoire was polyc lonal, but limited, in its junctional diversify by the relative lack o f N region nucleotide additions and by the frequent formation of codin g region joins at regions of short sequence homology, In addition, ide ntical TCRDV2 transcripts that resemble canonical TCR-delta sequences in mice were present in the intestine of different fetuses, In the ear ly period after birth, the intestinal TCR-delta repertoire was polyclo nal, and more diverse than the fetal repertoire, with junctional regio ns that contained extensive N nucleotide additions and frequently were as complex as those of adults, The intestinal TCR-delta repertoire sh owed increasing restriction with age and, by 14 to 17 yr, the repertoi re was oligoclonal and resembled the repertoire of individuals in the sixth to seventh decade, Moreover, the adult TCR-delta repertoire was almost identical at multiple sites throughout the intestine, suggestin g a model in which gamma delta T cell clones, selected by ligands in t he intestinal tract, undergo expansion and recirculation before lodgin g throughout the small intestine or colon.