Decreased mRNA expression of two FOXP3 isoforms in peripheral blood mononuclear cells from patients with rheumatoid arthritis and systemic lupus erythematosus.

Both the number and functional capacity of T-regulatory (Treg) cells are known to be decreased in various autoimmune diseases. FOXP3, an essential transcription factor for Treg cells, has three isoforms in humans, wild, and exon 2- and exon 2-exon 7-lacking, although their role in autoimmunity is not clearly understood. Here, we investigated the messenger RNA (mRNA) expression of the major wild and exon-2 isoforms in peripheral mononuclear cells by quantitative PCR methods in 56 subjects, consisting of 23 rheumatoid arthritis (RA) and 25 systemic lupus erythematosus (SLE) patients, and 8 healthy controls (HCs). Although mRNA expression of the two isoforms did not directly correlate with clinical disease activity, relative expression of both was significantly lower in SLE and RA patients than in HCs. Furthermore, we found a significant statistical correlation between the two isoforms, suggesting that they are similarly regulated. Decreased expression of these isoforms in RA and SLE may reflect Treg cell abnormalities in these autoimmune diseases.

Defective expression and tyrosine phosphorylation of the T cell receptor zeta chain in peripheral blood T cells from systemic lupus erythematosus patients.

We have reported that tyrosine phosphorylation and expression of the T cell receptor zeta chain (TCR zeta) was decreased in two systemic lupus erythematosus (SLE) patients with an abnormal TCR zeta lacking exon-7. To examine further the TCR zeta defect and any possible relationship with specific clinical features, we studied the expression of TCR zeta in peripheral blood T cells from 44 patients with SLE, 53 with other rheumatic diseases (30 rheumatoid arthritis (RA), 11 systemic sclerosis (SSc) and 12 primary Sjögren's syndrome(SjS)) and 39 healthy individuals. Flow cytometric analysis demonstrated a significant decrease in the expression of TCR zeta in SLE (P < 0.001), but not in the other rheumatic diseases. Immunoprecipitation experiments confirmed that the expression of TCR zeta in SLE T cells was decreased dramatically (normal: 111.4 +/- 22.6%, SLE: 51.6 +/- 37.4%, P < 0.0001). The decrease in TCR zeta did not correlate with disease activity, or with the dose of prednisolone (PSL). There were, however, three SLE patients in whom the level of TCR zeta expression normalized after treatment, suggesting that mechanisms responsible for the TCR zeta defect appear to be heterogeneous. These results confirm the defective expression and altered tyrosine phosphorylation of TCR zeta in a large proportion of SLE patients, suggesting that it may play an important role in T cell dysfunction in SLE.

T-cell receptor ζ mRNA with an alternatively spliced 3' untranslated region is generated predominantly in the peripheral blood T cells of systemic lupus erythematosus patients.

Abstract To investigate the mechanism of the downregulation of T-cell receptor ζ chain (TCRζ) expression in the peripheral blood T cells (PBTs) of systemic lupus erythematosus (SLE) patients, we analyzed the 3' untranslated region (3'UTR) of TCRζ mRNA, because the 3'UTR in mRNA is responsible for posttranscriptional regulation. Use of the reverse transcriptase polymerase chain reaction (RT-PCR) to amplify the 917 bp TCRζ 3'UTR cDNA demonstrated that the short variant cDNA (355 bp), expressed as an alternatively spliced 3'UTR with 562-bp deletion, was predominated in the PBTs of 11 of 14 SLE patients, whereas mainly the wild-form cDNA (917 bp) was detected in the PBTs of seven negative controls (two systemic sclerosis patients, five normal controls) and in two T-cell line hybridomas. Semiquantitative PCR also revealed the predominant expression of the TCRζ mRNA with alternatively spliced 3'UTR (TCRζ mRNA/as-3'UTR), and a decreased expression of TCRζ mRNA with the wild form 3'UTR (TCRζ mRNA/w-3'UTR) in SLE T cells. However, there was no difference in the expression of the open reading frame (ORF) TCRζ mRNA between the negative controls and SLE patients. The TCRζ protein expression level according to Western blot analysis correlated well with that of TCRζ mRNA/w-3'UTR (r= 0.931) and reversibly with TCRζ mRNA/as-3'UTR (r=-0.614), but not with ORF TCRζ mRNA (r=-0.296). It can be concluded that the reduced expression of TCRζ mRNA/w-3'UTR and the predominant expression of TCRζ mRNA/as-3'UTR lead to downregulation of the TCRζ protein in SLE T cells.

Soluble interleukin-2 receptor in blood from patients with sarcoidosis and idiopathic pulmonary fibrosis.

Soluble interleukin-2 receptor (sIL-2R) concentration is considered to reflect disease activity in patients with sarcoidosis. However, it remains to be evaluated whether or not the sIL-2R concentration reflects the total burden of granulomatous lesions, or if it can be a useful marker for other interstitial lung diseases such as IPF, the lesions of which are restricted to the lungs. In this study, we demonstrated that sIL-2R concentrations in 16 patients with active sarcoidosis increased (2031 +/- 1222 U/ml), compared to those in 29 patients with inactive disease (796 +/- 313), 24 with IPF (859 +/- 694) and 33 healthy controls (467 +/- 174). sIL-2R concentrations in patients with IPF also increased, more than those in healthy subjects. sIL-2R concentrations in 10 patients with extrathoracic lesions (ETL) were not different from those in 6 patients without ETL. Correlation between serum sIL-2R concentrations and serum ACE activity, BAL macrophage %, and BAL lymphocyte % was shown in patients with sarcoidosis. In patients with IPF, a correlation between sIL-2R concentrations and BAL macrophage % was found but there was no correlation between sIL-2R concentrations and BAL lymphocyte %. In conclusion, serum sIL-2R concentrations seem to reflect total inflammatory lesions. In addition, they reflect total inflammatory lesions of the lungs in sarcoidosis and IPF. For clinical purposes, its measurement may be more useful than that of BAL fluid concentrations in patients with sarcoidosis and IPF.

[Usefulness of the measurement of serum soluble IL-2 receptor alpha chain levels in clinical monitoring of non-Hodgkin lymphoma].

We measured the serum concentrations of the soluble form of interleukin-2 receptor alpha chain (sIL-2R alpha) in 25 patients with non-Hodgkin lymphoma (NHL) and 1 patient with virus-associated hemophagocytic syndrome (VHAS) by an enzyme-linked immunosorbent assay (ELISA) using two anti-IL-2R alpha monoclonal antibodies which recognize different epitopes. The sIL-2R alpha levels were markedly higher (n = 12, range = 469.2-11020 U/ml, mean +/- SD = 6153.0 +/- 1687.2 U/ml) in the sera of patients with NHL than in healthy individuals (n = 46, range = 290.1-849.3 U/ml, mean +/- SD = 459.8 +/- 126.9 U/ml, p < 0.01). The serum sIL-2R alpha levels in the NHL patients were closely associated with the stage of disease. The mean value of the serum sIL-2R alpha in each stage of NHL was as follows: stage I (469.2 U/ml, n = 1), stage II (4879.0 U/ml, n = 3), stage III (7364.8 U/ml, n = 8), stage IV (13796.2 U/ml, n = 10). However, there was no clear correlation between the elevation of serum sIL-2R alpha level and the pathological (LSG) classification of NHL. The serum sIL-2R alpha levels serially measured during the clinical course of 2 NHL patients were closely associated with the severity and the progression of the disease. Thus, the measurement of serum sIL-2R alpha levels is very useful not only for the diagnosis but also to monitor the clinical course of NHL.