B. Gulwaniakolkar et al., ANALYSIS OF THE PERIPHERAL-BLOOD T-CELL RECEPTOR (TCR) REPERTOIRE IN MONOZYGOTIC TWINS DISCORDANT FOR CROHNS-DISEASE, Autoimmunity, 17(3), 1994, pp. 241-248
T cell involvement in the inflammatory process of Crohn's Disease (CD)
is evident by an increase in activated T cells and their cytokines in
actively inflamed CD tissue. It has been suggested that CD may involv
e a superantigen based on the observation that a significant proportio
n of CD patients express elevated levels of Vbeta8+ T cells in their p
eripheral blood compared to normal controls. In order to determine whe
ther a superantigen might play a role in the pathogenesis of CD we hav
e compared the TCR repertoires of four pairs of monozygotic twins disc
ordant for CD. By using monozygotic twins, we could rule out the effec
ts of HLA and other genes on the TCR repertoire. The TCR repertoires w
ere analyzed by using a panel of V-segment-specific mAb and by quantit
ative polymerase chain reaction (qPCR) using Vbeta-specific oligonucle
otide primers. In all cases the TCR repertoires of the affected and un
affected sibs were strikingly similar. We did not observe any TCR segm
ent that was consistently altered in frequency or expression levels in
all of the affected sibs compared to their identical twin. Furthermor
e, we did not see an increase in Vbeta8+ T cells in the peripheral blo
od of the CD sibs relative to their normal counterpart. These studies
suggest that the presence of CD does not alter the TCR repertoire of p
eripheral blood in any obvious way and argue against the role of a sup
erantigen in the etiology or pathogenesis of CD.