Correlation between the phenotype and the functional capacity of activated T cells in patients with active systemic lupus erythematosus

Severe impairment of regulatory T-cells and Th1-lymphocyte polarization in patients with Gaucher disease

We investigated peripheral blood T-lymphocyte subpopulations and intracellular expression of IFN-γ, IL-4, IL-10, and IL-13, by whole blood flow cytometry, in 22 type I Gaucher disease (GD) patients. Results were compared with those of 19 sex- and age-matched controls. Patients with GD exhibited decreased frequencies and absolute numbers of CD3+/CD4+ helper T lymphocytes (40.8 ± 9.8% vs. 49.4 ± 5.7%, p = 0.002, and 0.77 ± 0.33 vs. 1.04 ± 0.28 × 10(9)/μL, p = 0.011), as well as increased frequencies of CD3+CD8+ suppressor T lymphocytes (23.8 ± 8.0% vs. 18.4 ± 3.8%, p = 0.010), resulting in a significantly decreased CD4/CD8 cell ratio (p < 0.001). Moreover, they had significantly increased percentages of IFNγ-producing both CD4+ and CD8+ T cells (p = 0.0003 and p = 0.023, respectively), implying a TH-1 polarization pattern. Finally, patients with GD had decreased percentages and absolute numbers of CD4+CD25(dim) T lymphocytes (p = 0.033 and p = 0.007, respectively), of CD4+CD25(high) T lymphocytes (p = 0.039 and p = 0.016, respectively), and of CD4+CD25(high)FOXP3+ regulatory T cells (p = 0.036 and p = 0.019, respectively). Our results demonstrate that patients with GD have a significant numerical impairment of T-helper lymphocytes and a constitutive TH1 direction pattern of activation of both CD4+ and CD8+ cells, associated with a significant decrease of T-regs. Ineffective T-cell control may explain the chronic inflammatory reaction and the increased incidence of lymphoid malignancies, which have been repeatedly reported among patients with GD.

Changes in the expression of telomere maintenance genes might play a role in the pathogenesis of systemic lupus erythematosus

Previous studies demonstrated that telomerase activity increased while telomere length shortened in peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE). This study aimed to examine the changes of telomere maintenance genes and their clinical significance in SLE. The mRNA level of telomeric proteins in PBMCs, including shelterin complex (TRF1, TRF2, POT1, TPP1, TIN2 and hRAP1), a set of multifunctional proteins involved in telomere maintenance (MRE11, KU80 and RPA1), and Ki67, was measured using real-time quantitative PCR in 56 SLE patients (36 treated and 20 untreated; 32 with renal involvement and 24 without renal involvement) and 46 healthy subjects (controls). The expression of TPP1, TIN2, POT1 and KU80 was significantly reduced while that of TRF2 and MRE11 increased in SLE patients ( p < 0.05, respectively); significant difference was not found in the expression of TRF1, hRAP1, RPA1 and Ki67 ( p > 0.05, respectively). The expression of TRF2, MRE11 and Ki67 was much higher in untreated SLE patients than in controls or treated SLE patients ( p < 0.05, respectively); the expression of hRAP1 was much higher in SLE patients with renal involvement than in controls or SLE patients without renal involvement ( p < 0.05, respectively). Significant positive correlation was found between level of KU80 and C3, TPP1 and TIN2, TPP1 and POT1, while significant negative correlation was found between KU80 and serum total globulins, TIN2 and RF, TPP1 and SLEDAI score ( p < 0.05, respectively). In conclusion, altered expression of telomere maintenance genes might be involved in the pathogenesis of SLE. Further study in expression and functions of telomeric proteins would be needed.

Decreased numbers of signal-joint T cell receptor excision circle-containing CD4+ and CD8+ cells in systemic lupus erythematosus patients

Systemic lupus erythematosus (SLE) patients have a decreased number of peripheral blood T cells containing signal-joint T cell receptor excision circles (Sj TRECs), which are considered an indicator of thymic output. The objective of this study was to investigate the mechanism of the decrease in such T cells. Peripheral blood T cells from SLE patients were classified into CD4+ and CD8+ cells. Sj TREC levels were measured by real-time PCR. Telomerase activity was determined by the telomeric repeat amplification protocol assay. The numbers of Sj TREC containing CD4+ and CD8+ cells were lower in the peripheral blood of SLE patients than in the controls. A correlation was found between the numbers of Sj TREC-positive CD4+ and CD8+ cells. The level of TRECs is influenced by an increase in cell division. To examine this increase, telomerase activity as an indicator of cell division was measured simultaneously; however, there was no correlation between the Sj TREC level and telomerase activity. These results suggest that decreased thymic output occurs in SLE patients.

Telomerase activity and telomere length of peripheral blood mononuclear cells in SLE patients

We evaluated the clinical significance of the telomerase activity and telomere length of peripheral blood mononuclear cells (PBMC) in systemic lupus erythematosus (SLE). PBMC were isolated from 55 patients with SLE and the telomerase activity was measured by TRAP assay. The telomere length of PBMC was also measured in 30 of these subjects. As a control group, 45 healthy adults with no particular clinical history were studied. The results were compared with clinical data. In patients with active SLE, the telomerase activity of PBMC was significantly increased compared with the control group. In patients with inactive SLE, the PBMC telomerase activity was not different compared with the controls in their 20s, 30s and 40s, but it was significantly increased compared with the controls in their 50s. In SLE patients, the telomerase activity of PBMC was significantly correlated with modified SLEDAI. The telomere length of PBMC in younger SLE patients tended to be shorter than that in the controls, but no difference was observed in older patients. The correlation coefficient between the telomerase activity and telomere length of PBMC in SLE patients was not significant. Abnormalities in the telomerase activity and telomere length observed in SLE patients are considered to be important findings for evaluation of the pathology of SLE.

Impaired recovery and cytolytic function of CD56+ T and non-T cells in systemic lupus erythematosus following in vitro polyclonal T cell stimulation. Studies in unselected patients and monozygotic disease-discordant twins

OBJECTIVE

To determine whether there is impaired generation and cytolytic function of CD56+ T cells and non-T cells in human systemic lupus erythematosus (SLE).

METHODS

Peripheral blood mononuclear cells (PBMC) were obtained from 73 patients with SLE, 39 normal controls, and 9 pairs of monozygotic (MZ) twins discordant for SLE. PBMC were stimulated with anti-CD3 monoclonal antibody, maintained in interleukin-2, and assayed for percentages of total CD56+ cells and CD56+ T cells by flow cytometry, and for cytolytic activity against 51Cr-labeled Daudi target cells.

RESULTS

Despite normal total cell expansion, the percentages of recovered CD56+ T cells and total CD56+ cells were 1.6-fold and 1.8-fold lower, respectively, in patients with SLE compared with normal controls (P = 0.011 and P < 0.001, respectively). Cytolytic activities of isolated total CD56+ cells and CD56+ T cells and were also reduced in patients with SLE compared with normal controls (P = 0.033). These defects associated with SLE were independent of disease activity and immunosuppressive medications, and they reflected impaired maturation of cytolytic effector cells rather than a deficiency in precursor cell number. In MZ twins discordant for SLE, recovered percentages of CD56+ cells and cytolytic responses were very low in 4 of 8 and 6 of 9 co-twins with SLE, respectively. Cellmixing experiments with the PBMC of the MZ twins demonstrated that the E+ cell fractions (containing all T cells and CD56+ non-T cells) from the co-twins with SLE had decreased ability to generate cytolytic activity compared with the corresponding E+ cell fractions from the healthy co-twins. However, recovered percentages of CD56+ cells and non-T cells and cytolytic responses were also depressed in 4 of 8 and 4 of 9 healthy co-twins, respectively.

CONCLUSION

Impaired CD56+ T cell and non-T cell responses are a feature of SLE and may antedate the onset of clinical disease.

Impaired polyclonal T cell cytolytic activity. A possible risk factor for systemic lupus erythematosus

OBJECTIVE

To determine whether impaired generation of polyclonal T cell cytolytic activity is over-represented in systemic lupus erythematosus (SLE) compared with other rheumatologic diseases and whether such impaired generation of cytolytic activity waxes and wanes with disease activity and/or changes in medications.

METHODS

Peripheral blood mononuclear cells from 84 SLE patients, 55 rheumatologic disease (RD) controls, and 44 normal subjects were stimulated with anti-CD3 monoclonal antibody, maintained in interleukin-2, and assayed for cytolytic activity against 51Cr-labeled Daudi target cells.

RESULTS

Generation of cytolytic activity was significantly lower in SLE patients than in either RD or normal controls. Abnormal cytolytic responses in SLE could not be attributed to the patient's sex, race, age, disease activity, or antirheumatic medications (including corticosteroids and cytotoxics), although both SLE and RD patients taking azathioprine (AZA) manifested lower responses than did corresponding patients not taking AZA. Abnormal cytolytic activity reflected, in large measure, impaired cytolytic activity of CD8+ T cells. No significant difference in the generation of cytolytic activity between RD and normal controls was detected.

CONCLUSION

Impaired generation of polyclonal T cell cytolytic activity may be a predisposing factor in the development of SLE.

Up-regulated expression of Fas antigen (CD95) by peripheral naive and memory T cell subsets in patients with systemic lupus erythematosus (SLE): a possible mechanism for lymphopenia

Fas antigen (CD95) is a membrane-associated molecule that mediates apoptotic cell death and may play a role in the induction and maintenance of T cell tolerance. To elucidate the involvement of Fas antigen in human autoimmune diseases, we analysed Fas antigen expression by peripheral T cells from patients with SLE and rheumatoid arthritis (RA), using three-colour flow cytometry. Both CD4+ and CD8+ T cells from SLE patients expressed Fas antigen in a higher density than did these cells from healthy donors and from RA patients. Enhancement of Fas antigen density was noted in Fas+CD45RO+ memory T cells from SLE patients. More remarkably, a significant expression of Fas antigen was observed in CD45RO- naive T cells from SLE patients. CD4+CD45RO- T cells from SLE patients co-expressed Fas antigen and early to intermediate activation antigens such as CD25 and CD71, and late activation antigen HLA-DR in only FashiCD4+ naive T cells. Such up-regulation of Fas antigen expression in SLE patients seems to be clinically meaningful, because mean fluorescence intensity (MFI) of Fas antigen on CD4+ T cell subsets inversely correlates with the absolute size of CD4+ T cell subsets in peripheral blood of SLE patients. These results suggest that T cells with increased Fas antigen expression may be highly susceptible to apoptotic cell death, in vivo. A putative mechanism for lymphopenia in SLE patients is discussed.

Immune restoration in children after partial splenectomy

Splenectomy (SE) is recognized to be a therapeutical approach in treating children with severe autoimmune diseases (chronic idiopathic thrombocytopenia; hemolytic anemia) or hypersplenism because of portal hypertension. Nevertheless, removal of a main immune organ results in elevated infection risk for these patients. Partial splenectomy (PSE) was developed as a therapeutical compromise to retain immunologically active spleen tissue. Here, we document the analysis of immune parameters obtained from children after both partial and total splenectomy, which have been followed up for a period of more than 6 years: (i) Lymphocytes from both groups of patients failed to produce IgG in response to pokeweed mitogen in vitro. This was observed in 11/20 splenectomized patients even 10 years after operation, whereas in PSE patients a restoration of this parameter after 1-2 years was seen. (ii) In patients after PSE, but not in splenectomized persons, an elevated number of HLA-class II positive cells had been detected suggesting a different situation of immune regulation following this operation. However, in parallel with an improvement of B cell in vitro activity this parameter was found to achieve normal values. Our findings indicate that partial splenectomy may be a therapeutical alternative, if the therapeutic goal can be achieved by this procedure.

An early activation antigen of murine T cells recognized by monoclonal natural autoantibody NTA204 and the expression on T cells from aged NZB x NZW F1 mice with overt autoimmune disease

A monoclonal natural thymocytotoxic autoantibody NTA204 established from an autoimmune-prone NZB mouse reacted with the majority of thymocytes, all peripheral B cells, granulocytes and bone marrow myeloid cells, but not with peripheral resting T cells of normal mice. In aged NZB/W F1 mice with overt autoimmune disease, the population of NTA204+ CD4+ CD25- T cells was remarkably increased. The NTA204 antigen could be induced on splenic T cells from normal healthy mice as early as 3 hr after the initiation of culture with stimulant Con A, and was expressed on the vast majority in the 48-hr culture. The expression preceded that of other T cell activation antigens tested, CD25 and CD45R. Cell cycle analysis suggested that NTA204 is expressed at an early phase of G1A. T cells, particularly CD8+ T cells, in the allogeneic mixed lymphocyte culture (MLC) could be divided into two populations, NTA204+ and NTA204-. By immunohistochemical analysis, 30% of NTA204+ CD8+, but few NT204- CD8+ T cells were intensely positive for large cytoplasmic granules of perforin, an important cytolytic mediator of cytotoxic T cells. Thus the increased population of NTA204+ T cells in aged NZB/W F1 mice appear to be activated T cells and might be at least partly involved in the pathogenesis of disease in these mice. Immunoblotting analysis of Con A-activated splenic T cells showed that NTA204 molecules have a molecular mass of 49 Kd.

Increased expression of proliferating cell nuclear antigen mRNA in peripheral blood mononuclear cells from patients with IgA nephropathy

Proliferating cell nuclear antigen (PCNA)/cyclin is an intranuclear polypeptide antigen whose appearance correlates with the proliferative state of cells. The authors investigated the expression of PCNA from peripheral blood mononuclear cells (PBMC) in 23 patients with IgA nephropathy and 10 healthy age-matched controls, using ribonucleic acid hybridization techniques. The majority of patients with IgA nephropathy (22 of 23 patients) showed elevated PCNA expression in PBMC, while no PCNA expression was detected in PBMC of normal controls. A positive correlation was noted between PCNA expression of PBMC and glomerular injuries and PCNA expression and urinary protein excretion. Sixty-three percent of patients with grade III and IV histological findings showed strong PCNA (more than ) expression in their PBMC. The urinary protein excretion in patients who showed more than ( ) PCNA expression was more than 2.5 g/d, while that in patients with less than (+) PCNA expression was less than 1.0 g/day. These findings indicate that abnormally regulated PCNA expression in PBMC may play an important role in the progression of IgA nephropathy, and that PCNA expression in PBMC may be a useful indicator of disease activity.

CD8+ lymphocytes from patients with systemic lupus erythematosus sustain, rather than suppress, spontaneous polyclonal IgG production and synergize with CD4+ cells to support autoantibody synthesis

The cellular requirements for B cell hyperactivity in systemic lupus erythematosus (SLE) were studied. Removal of either CD8+ or CD4+ lymphocyte markedly decreased the spontaneous in vitro production of polyclonal IgG and of antigen-specific (anti-double-stranded DNA and antinucleoprotein) antibodies by SLE peripheral blood mononuclear cells (PBMC). The CD8+ lymphocytes that sustained IgG production were CD3+, HLA-DR+, and their activity was abrogated by preincubation with anti-HLA-DR monoclonal antibody. When both CD4+ and CD8+ cells were removed, the readdition of either subset partially restored polyclonal IgG production, but both cell subsets were required to reconstitute autoantibody production. Purified SLE B cell cultures, which generated only 15% of the IgG produced by unseparated PBMC, were fully reconstituted only by mixtures of CD4+ with CD8+ cells, and with CD8-, CD4-, CD16+ cells. At least part of the support for spontaneous IgG production can be attributed to endogenous interleukin-2 and interleukin-6.

HLA-DP+ T cells and deficient interleukin-2 production in patients with systemic lupus erythematosus

In patients with systemic lupus erythematosus (SLE), frequency of the T cells positive for HLA-DP, one of the major histocompatibility complex (MHC) class II molecules, was markedly increased in peripheral blood lymphocytes (PBL), in association with an increase in the amount of specific cytoplasmic transcript of the HLA-DP gene segment. Cell cycle analysis showed that HLA-DP is an early activation marker of T cells and that the high ratios of HLA-DP+ T cells from SLE patients are associated with high frequency of T cells at early activation phases, mainly of G1A. Initial high ratios of HLA-DP+ T cells decreased to a great extent during 4 days of in vitro culture, in the absence of mitogens. This event was associated with decreases in the amount of HLA-DP transcript and the disappearance of activated T cells. Studies on the interleukin 2 (IL-2) production of T cells from patients with SLE demonstrated that while the PBL rich in HLA-DP+ T cells show a markedly low production of IL-2, preculture of these PBL restores the ability to produce IL-2. Thus, it appears that the T cells in patients with SLE are essentially intact with regard to the capacity to produce IL-2 and that T cell activation events continuously occurring in SLE patients are related to a deficiency in IL-2 production. The possible underlying mechanisms are discussed.

Activated peripheral blood mononuclear cells detected by murine monoclonal antibodies to proliferating cell nuclear antigen in active lupus patients

Hybridoma producing monoclonal antibody to proliferating cell nuclear antigen (PCNA/cyclin) (TOB7, IgG1 kappa) was newly established. Using TOB7, PCNA was detected in the peripheral blood mononuclear cells (PBMC) in patients with systemic lupus erythematosus (SLE). Forty-four of 58 patients with SLE had PBMC expressing PCNA. The percentage of PCNA-positive PBMC in patients with SLE was 0-20% (mean: 2.63%) which was significantly higher (P less than 0.01) compared with normal controls (mean: 0.18%), patients with rheumatoid arthritis (mean: 0.83%), and patients with mixed connective tissue disease (mean: 0.38%). Patients with high numbers of PCNA positive PBMC tended to complicate pulmonary disorders (P less than 0.005), especially pulmonary fibrosis (P less than 0.005). In addition, the percentage of PCNA-positive cells in SLE patients correlated with the disease activity (r = 0.45, P less than 0.01). The lymphocyte subsets of PCNA-positive PBMC were examined, and most of those cells belonged to CD4- or CD8-positive T-cell populations in three lupus patients. Our findings indicate that PCNA-positive activated PBMC are present in SLE patients and the percentage of PCNA-positive PBMC may be used as an indicator of disease activity.

Systemic lupus erythematosus of childhood onset: correlation between T cells expressing early and late activation antigens and disease activity

Correlation between T cell phenotypes, especially activated T cells expressing early (EA1) and late (HLA-DR) activation antigens and clinical features were investigated in 22 patients with systemic lupus erythematosus (SLE) of childhood onset. Percentages of T cells expressing EA1 and HLA-DR in 22 patients with SLE were significantly higher than those in controls. Comparison of T cell phenotypes between patients with active and inactive SLE showed that eight patients with active disease had significantly increased percentages of HLA-DR positive T cells than 14 with inactive disease (P less than 0.01). Serial examinations showed that the percentages of HLA-DR positive T cells were decreased after therapy in seven with active non-renal or active non-renal and renal diseases but not in one with only active renal disease. A possible significance of T cells expressing EA1 and HLA-DR in the management of patients with SLE is discussed.

A myelopeptide from unstimulated bone marrow cells with immunomodulatory activity in lymphocyte cultures from healthy donors and patients with hypogammaglobulinemia and active lupus erythematosus

A myelopeptide (SAP) was derived from culture supernatants of unstimulated animal bone marrow. SAP consists of a group of peptides with a molecular weight of about 2000 D, having a broad variety of biological activities. Testing immunoregulatory properties of the purified factor Petrov, Mickhailova & Zacharova [(1971). Immunoglobin synthesis in syngenic cells of different lymphoid tissues. J. Immun., 106 1086-1089] found enhanced antibody production in mice (SAP-stimulator of antibody production). We show here that the substance could induce expression of activation markers on human lymphocytes (4F2, HLA-class II antigens, thermostable SE rosette formation) and potentiate their appearance in combination with mitogens (PWM, PHA, Con A). Although SAP was not mitogenic for itself, it enhanced lectin-induced 3H-thymidine incorporation and T-cell-dependent B-cell differentiation in a dose-dependent manner. The factor was able to reconstitute disturbed PWM-driven Ig synthesis in lymphocyte cultures derived from two patients with hypogammaglobulinemia and a healthy non-responder to PWM. On the other side, SAP potentiated the inhibitory activity of PWM on elevated spontaneous IgG secretion in cultures derived from patients with active SLE. Findings of this study indicate immunomodulatory capacity of SAP on human peripheral blood lymphocytes possible via T-cell activation. The results suggest a potential therapeutic application of SAP in patients with disturbances in the T-dependent B-cell differentiation.

Quantitative defect of CD4+2H4+ cells in systemic lupus erythematosus and Sjögren's syndrome

Surface antigens of T lymphocytes in peripheral blood mononuclear cells from 19 patients with systemic lupus erythematosus (SLE), 14 patients with Sjögren's syndrome (SS), and 14 healthy control subjects were studied by 2-color analysis. The proportion of CD4+2H4+ cells, which correspond to a suppressor/inducer subset, was decreased significantly in both SLE and SS. In contrast, the percentage of CD4+4B4+ cells, which define a helper/inducer subset, showed no significant difference among the patient groups. These data suggest that quantitative defect of suppressor/inducer cells may play an important role in the immunoregulatory disturbance in SLE and SS.

Increased percentage of activated Ia+ T lymphocytes in peripheral blood of neonates following exchange blood transfusion

The expression of Ia-like antigens in peripheral blood T lymphocytes from newborns receiving postnatal total blood exchange was analyzed. A significantly increased percentage of Ia-positive T lymphocytes (Ia+ T cells) was observed 2 days after postnatal transfusion with total blood in comparison to data observed on Days 0, 5, and 15. Ia+ T cells were also significantly higher than in normal control newborns tested in the same period. When newborns received the blood exchange with irradiated total blood or with leukocyte-depleted blood, no increase in Ia+ T cells was observed and the percentage of these cells remained in the normal range (1-7%) on all the days tested (0, 2, 5, 15 days). For easy identification of the origin of Ia+ T cells, sex-incompatible blood was used for exchange, and a karyotype analysis was carried out for the detection of the Y chromosome on Ia+ T cells separated from peripheral blood on Day 2 and then cultured with interleukin 2 (IL-2) for 48 hr. It was thus established that Ia+ T cells were not of donor origin. Simultaneously with the expression of Ia-like antigens, host T cells also carried the interleukin-2 receptor (TAC). An allogeneic response, comparable to a host-versus-graft reaction, was probably responsible for the activation of T cells 2 days after total blood exchange in newborns.

The influence of interferon-gamma, interleukin-2, prostaglandin E2, and cyclosporine on the polyclonal and anti-DNA antibody secretion in lymphocyte cultures derived from patients with systemic lupus erythematosus

The influence of various immunoregulatory substances was studied in lymphocyte cultures derived from patients suffering from systemic lupus erythematosus (SLE) by using the model of spontaneous secretion of polyclonal immunoglobulin G (IgG)/immunoglobulin M (IgM) and anti-DNA autoantibodies. Compared with healthy donors, lymphocytes derived from patients with active SLE disease showed an elevated secretion of total IgG as well as anti-DNA-IgG in vitro, which was associated with an increase in the proportion of activated (HLA-class II +) T cells in their peripheral blood. Recombinant interferon-gamma increases the total IgG/IgM as well as anti-DNA-IgG/IgM secretion, which suggests that it has a possible role in the pathogenesis of SLE disease. Recombinant interleukin-2 and prostaglandin E2 normalize the high, spontaneous total IgG secretion, but elevate anti-DNA-IgG/IgM secretion. These results suggest that autoreactive B-cell clones are regulated differently in SLE patients. Cyclosporine inhibits total IgG/IgM secretion in all patients and anti-DNA-IgG/IgM secretion in six of eight patients. The possible therapeutic use of such immunomodulatory substances in SLE disease is discussed.