Biased T cell receptor Vbeta gene expression in bronchoalveolar lavage fluid from Japanese patients with sarcoidosis.
OBJECTIVE
Sarcoidosis is believed to be one of the T cell-mediated granulomatous diseases with unknown aetiology. We attempt to search for the causative T cell clones of sarcoidosis.


METHODS
We study T cell receptor beta-chain variable region (Vbeta) repertoire in peripheral blood (PB) and bronchoalveolar lavage fluid (BALF) from patients with sarcoidosis, using semi-quantitative reverse transcriptase-polymerase chain reaction method. The expression of 22 kinds of Vbeta genes is examined in 17 patients with sarcoidosis and nine normal subjects.


RESULTS
Compared with control subjects, the group with sarcoidosis exhibits significantly high expressions of the Vbeta2 (P < 0.005, Wilcoxon's test) and Vbeta6 (P = 0.005) genes in BALF. In each BALF sample, the Vbeta2 (P < 0.01, chi2 test) and Vbeta6 (P < 0.01) genes were overexpressed (> 2 SD above the mean value for each Vbeta observed in control subjects) in 11 and 10 of 17 patients with sarcoidosis, respectively. Furthermore, the amino acid sequences of Vbeta6+ complementarity determining region 3 were conserved in one of three patients. There is, however, no disposition of Vbeta gene usage in PB from patients with sarcoidosis compared with control subjects.


CONCLUSIONS
The T lymphocytes with Vbeta2 and/or Vbeta6 are associated with the pathogenesis of sarcoidosis. The possibility exists that these T lymphocytes might be capable of recognizing the restricted antigens, thereby inducing oligoclonal expansion.
Yoshitomi
A
A
Second Department of Internal Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan.
Sato
A
A
Hayakawa
H
H
Chida
K
K
Toyoshima
M
M
Uchijima
M
M
Yoshida
A
A
Koide
Y
Y
D000328:Adult; D000595:Amino Acid Sequence; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D005260:Female; D015870:Gene Expression; D019674:Genes, T-Cell Receptor beta / Q000235:genetics*; D005819:Genetic Markers / Q000502:physiology; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012507:Sarcoidosis / Q000097:blood / Q000235:genetics*; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
D005819:Genetic Markers