@article {Lim683, author = {S H Lim and P Stephens and Q X Cao and S Coleman and D W Thomas}, title = {Molecular analysis of T cell receptor beta variability in a patient with orofacial granulomatosis.}, volume = {40}, number = {5}, pages = {683--686}, year = {1997}, doi = {10.1136/gut.40.5.683}, publisher = {BMJ Publishing Group}, abstract = {BACKGROUND: Orofacial granulomatosis (OFG) is a rare chronic inflammatory disorder of unknown causation and is characterised histologically by non-caseating granulomas and aggregates of small lymphocytes. The molecular nature of these T cells is, however, unclear. AIMS: To determine the T cell receptor (TCR) V beta gene usage of the T cell infiltrate associated with the primary lesions in a patient with OFG. METHODS: A molecular method involving reverse transcriptase (RT)-polymerase chain reaction (PCR), DNA cloning, single strand conformation polymorphism (SSCP), length analysis, and nucleotide sequencing was used. RESULTS: Compared with peripheral blood lymphocytes from the same patient, notably restricted TCRV beta gene usage was observed in the T cell infiltrate. Only three of the 24 major TCRV beta gene families were represented in the repertoire. There was preferential usage of the V beta 6 gene. In addition, more than 20\% of the V beta 6 TCR transcripts exhibited an identical unique V-D-J junctional sequence, suggesting a local antigen driven V beta 6 T cell clonal expansion in vivo, a phenomenon not observed in normal oral mucosa. CONCLUSIONS: The TCRV beta repertoire of T cells associated with OFG is restricted. It is also associated with a local T cell clonal expansion. The results, therefore, provide a new perspective on the immunopathology of OFG.}, issn = {0017-5749}, URL = {https://gut.bmj.com/content/40/5/683}, eprint = {https://gut.bmj.com/content/40/5/683.full.pdf}, journal = {Gut} }