[Changes in T-cell receptor repertoire in aplastic anemia and effects of Shengxue Mixture].

OBJECTIVE: To explore the immune pathogenesis of aplastic anemia (AA) and the therapeutic effects of Shengxue Mixture (SM) through the gene expressions of subfamilies of T-cell receptor variable region beta (TCR Vbeta) using immunologic and molecular biologic technology. METHODS: Gene expressions of TCR Vbeta sub-families in peripheral blood mononuclear cells from 20 AA patients were detected before and after treatment with SM using RT-PCR and gene scanning method. RESULTS: TCR Vbeta gene repertoire of the 24 subfamily genes deviated in AA patients, and the oligoclonal gene expressions increased obviously compared with those in healthy people (P < 0.01), including Vbeta2, 5, 6, 15, 16, 22, and 23 were found in 30%-50% AA patients, and Vbeta8, 21 were in more than 50% patients. These oligoclonal genes reduced significantly after treatment with SM compared with those before treatment (P < 0.05). CONCLUSION: Multiple TCR Vbeta subfamilies of clonal proliferation participate in the pathogenesis of AA. SM can rectify the deviation of TCR Vbeta gene repertoire, reduce the abnormal clonal proliferation of T cells, thus to alleviate the immune injury to hematopoietic tissue, and thus to benefit the recovery of hematopoiesis of bone marrow.

Changes in T-cell receptor repertoire in aplastic anemia and effects of Shengxue Mixture / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the immune pathogenesis of aplastic anemia (AA) and the therapeutic effects of Shengxue Mixture (SM) through the gene expressions of subfamilies of T-cell receptor variable region beta (TCR Vbeta) using immunologic and molecular biologic technology.</p><p><b>METHODS</b>Gene expressions of TCR Vbeta sub-families in peripheral blood mononuclear cells from 20 AA patients were detected before and after treatment with SM using RT-PCR and gene scanning method.</p><p><b>RESULTS</b>TCR Vbeta gene repertoire of the 24 subfamily genes deviated in AA patients, and the oligoclonal gene expressions increased obviously compared with those in healthy people (P < 0.01), including Vbeta2, 5, 6, 15, 16, 22, and 23 were found in 30%-50% AA patients, and Vbeta8, 21 were in more than 50% patients. These oligoclonal genes reduced significantly after treatment with SM compared with those before treatment (P < 0.05).</p><p><b>CONCLUSION</b>Multiple TCR Vbeta subfamilies of clonal proliferation participate in the pathogenesis of AA. SM can rectify the deviation of TCR Vbeta gene repertoire, reduce the abnormal clonal proliferation of T cells, thus to alleviate the immune injury to hematopoietic tissue, and thus to benefit the recovery of hematopoiesis of bone marrow.</p>

Aberrant transcription of unrearranged T-cell receptor beta gene in mouse brain.

The nervous system and the immune system share several functional molecules involved in various cell-cell interaction events. In this study, we used in situ hybridization to identify immune molecules that are expressed by a restricted population of neurons in the mouse brain and found that mRNA for the beta subunit of T-cell receptor (TCRbeta) was predominantly and strongly localized to neurons in deep layers of the cerebral neocortex and weakly expressed in the thalamus. Developmentally, TCRbeta mRNA expression started at embryonic day 15 in the thalamic nuclei and at postnatal day 1 in the cerebral neocortex. The level of TCRbeta mRNA in the neocortex subsequently increased until postnatal day 21, and it remained high in the adult. Detailed analysis revealed that only the Cbeta2 segment of TCRbeta, not the Cbeta1 or Vbeta segments, was expressed by the brain neurons. By the 5' rapid amplification of cDNA ends method, we determined a brain-specific transcription start site in the Jbeta2 region locus, not in the Vbeta region locus. Furthermore, we confirmed that the aberrant transcription around the Jbeta2 region took place only in neurons and lymphocytes in transgenic mice. These results demonstrate that the transcriptional machinery for unrearranged TCRbeta expression is shared by the nervous and immune systems and raise a possibility of gene rearrangement in neurons under certain circumstances.

The T cell response to Art v 1, the major mugwort pollen allergen, is dominated by one epitope.

Mugwort (Artemisia vulgaris) pollen allergens represent the main cause of pollinosis in late summer in Europe. At least 95% of sera from mugwort pollen-allergic patients contain IgE against a highly glycosylated 24- to 28-kDa glycoprotein. Recently, this major allergen, termed Art v 1, was characterized, cloned in Escherichia coli, and produced in recombinant form. In the present study we characterized and compared the T cell responses to natural (nArt v 1) and recombinant Art v 1 (rArt v 1). In vitro T cell responses to nArt v 1 and rArt v 1 were studied in PBMC, T cell lines (TCL), and T cell clones (TCC) established from PBMC of mugwort-allergic patients. Stimulation of PBMC or allergen-specific TCL with either nArt v 1 or rArt v 1 resulted in comparable proliferative T cell responses. Eighty-five percent of the TCC reactive with rArt v 1 cross-reacted with the natural protein. The majority of the CD4(+)CD8(-)TCR alphabeta(+) Art v 1-specific TCC, obtained from 10 different donors, belonged to the Th2 phenotype. Epitope mapping of TCL and TCC using overlapping peptides revealed a single immunodominant T cell epitope recognized by 81% of the patients. Inhibition experiments demonstrated that the presentation of this peptide is restricted by HLA-DR molecules. In conclusion, the T cell response to Art v 1 is characterized by one strong immunodominant epitope and evidently differs from the T cell responses to other common pollen allergens known to contain multiple T cell epitopes. Therefore, mugwort allergy may be an ideal candidate for a peptide-based immunotherapy approach.

T cell receptor Vbeta expression in patients with allergic asthma before and after repeated low-dose allergen inhalation.

The objective of this study was to identify disease-associated T cell subsets by characterizing the lung and blood T cell receptor (TCR) repertoires in allergic asthmatics before and after repeated low-dose allergen challenge. Peripheral blood lymphocyte (PBL) and bronchoalveolar lavage (BAL) samples were obtained from eight patients with allergic asthma before and after a period of repeated low-dose allergen inhalations. RT-PCR followed by Southern blot allowed the quantification of relative Vbeta gene segment usage. Thirteen healthy individuals served as controls at PBL level. PBL as well as BAL T cells of asthmatics displayed a higher usage of Vbeta3, Vbeta5.2, and Vbeta6.1-3 and a lower usage of Vbeta16, Vbeta18, and Vbeta19 compared to PBL of healthy controls. Interestingly, TCR Vbeta7 and Vbeta9 usage was significantly higher in BAL than in PBL in asthmatics before as well as after challenge. TCR repertoire alterations after allergen challenge differed between individuals, with relatively mild changes.