T-CELL RECEPTOR V-BETA EXPRESSION IN HUMAN INTESTINE - REGIONAL VARIATION IN POSTNATAL INTESTINE AND BIASED USAGE IN FETAL GUT

A panel of T cell receptor V beta specific monoclonal antibodies was u sed to analyse V beta gene usage at different sites in human postnatal and fetal intestine. In normal small intestine, at a single site, dif ferent patients showed expansion of T cells expressing individual V be ta s. Lamina propria and epithelial T cells from the same patient show ed overlapping but not identical V beta dominance. V beta dominance wa s also shown in the T cells of the colonic lamina propria. Analysis of two separate regions of intestine from the same patient (5-100 cm apa rt) showed that T cells expressing a dominant V beta region were often present at both sites. In most patients, however, major biases in T c ell V beta usage (two to 12-fold variation) were also apparent between the two sites. Analysis of V beta expression in human fetal intestine also showed considerable skewing, although the most common dominant V beta in postnatal intestine (V beta 22) was never predominant in feta l intestine. Patchy local variation in the expression of individual V beta s therefore occurs against a background of V beta dominance over large regions of the human gut. Furthermore the results from fetal gut show that factors other than luminal antigen control V beta expressio n in the gut.