[T-cell receptor V alpha gene repertoire and clonal expansion in benzene-exposed workers].
OBJECTIVE
To observe the distribution of TCR V alpha gene repertoire and clonal expansion in peripheral blood mononuclear cells from 9 donors and 16 workers exposed to benzene.


METHODS
Complementarity determining region 3 (CDR3) of TCR V alpha subfamily genes were amplified using RT-PCR. The PCR products were further analyzed by genescan to evaluate clonality of T cells.


RESULTS
Almost all of 29 V alpha subfamily could be detected in 9 donors. 1 approximately 11 V alpha subfamilies were identified in all but one of the workers studied. The most frequently expressed V alpha subfamily were V alpha 3, V alpha 12 and V alpha 19 (68.8%), V alpha 14 (56.3%), with a lower expression rate found in V alpha 5, V alpha 15, V alpha 16, V alpha 22, V alpha 23 and V alpha 24 (6.3%). Clonal expansion T cells in one or more V alpha subfamily were found in 12 out of all workers studied, including oligoclonal, oligoclonal trend and biclonal patterns. The frequency of clonal expansion T cells in V alpha 12, V alpha 14 and V alpha 19 subfamilies were higher than others.


CONCLUSIONS
Skewed distribution and clonal expansion of TCR V alpha subfamily T cells could be found in workers exposed to benzene. V alpha 12, V alpha 14 and V alpha 19 subfamilies may be highly sensitive to benzene exposed. This is the first report of clonal expansion TCR V alpha T cells in the benzene-exposed group. The bias pattern of TCR V alpha T cells may be due to the immune cytotoxicity from benzene. However, whether the oligoclonality in some V alpha subfamilies reflect the phenomenon of clone absence or may be a response clone to benzene-related impairment during exposed to benzene, remains an open question.
Li
Bo
B
Institute of Hematology, Medical College, Jinan University, Guangzhou 510632, China.
Li
Yang-qiu
YQ
Yang
Li-jian
LJ
Chen
Shao-hua
SH
Yu
Wei
W
Liu
Wei-wei
WW
Chen
Jia-yu
JY
D000328:Adult; D001554:Benzene / Q000506:poisoning*; D022801:Complementarity Determining Regions / Q000235:genetics*; D005260:Female; D020869:Gene Expression Profiling; D019673:Genes, T-Cell Receptor alpha / Q000235:genetics*; D006801:Humans; D007963:Leukocytes, Mononuclear; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000235:genetics*; D055815:Young Adult
D022801:Complementarity Determining Regions; D001554:Benzene