Association between senescence of T cells and disease activity in patients with systemic lupus erythematosus

T-cell senescence: A crucial player in autoimmune diseases

Senescent T cells are proliferative disabled lymphocytes that lack antigen-specific responses. The development of T-cell senescence in autoimmune diseases contributes to immunological disorders and disease progression. Senescent T cells lack costimulatory markers with the reduction of T cell receptor repertoire and the uptake of natural killer cell receptors. Senescent T cells exert cytotoxic effects through the expression of perforin, granzymes, tumor necrosis factor, and other molecules without the antigen-presenting process. DNA damage accumulation, telomere damage, and limited DNA repair capacity are important features of senescent T cells. Impaired mitochondrial function and accumulation of reactive oxygen species contribute to T cell senescence. Alleviation of T-cell senescence could provide potential targets for the treatment of autoimmune diseases.

Different Types of Chronic Inflammation Engender Distinctive Immunosenescent Profiles in Affected Patients

Immunosenescence encompasses a spectrum of lymphocyte phenotypic alterations. The aim of the study was to evaluate immunosenescent effect of two different forms of chronic inflammation, Systemic Lupus Erythematosous (SLE), a systemic autoimmune disease, and End-Stage Kidney Disease (ESKD), a chronic inflammatory disorder. Certain lymphocyte surface molecules, including CD31, CD45RA, CCR7, CD28, CD57, for T, and IgD, CD27 for B lymphocytes, were analyzed by flow cytometry in 30 SLE and 53 ESKD patients on hemodialysis (HD), and results were compared to 31 healthy controls (HC) of similar age, gender, and nationality. Significant Lymphopenia was evident in both SLE and ESKD-HD patients, compared to HC, affecting B cells 75.4 (14.4−520.8), 97 (32−341), and 214 (84−576) cells/μL, respectively, p < 0.0001, and CD4 cells 651.2 (71.1−1478.2), 713 (234−1509), and 986 (344−1591) cells/μL, respectively, p < 0.0001. The allocation of B cell subpopulations was remarkably different between SLE and ESKD-HD patients. SLE showed a clear shift to senescence (CD19IgD-CD27−) cells, compared to ESKD-HD and HC, 11.75 (10)% vs. 8 (6) vs. 8.1 (10), respectively. Regarding T lymphocytes, Central Memory CD8 cells predominated in both SLE and ESKD-HD patients compared to HC, 53 (50)%, 52 (63), and 24 (64)%, respectively, while ESKD-HD but not SLE patients also had increased expression of CD4CD28− and CD8CD28− cells. In conclusion, both diseases are followed by significant lymphopenia; however, the senescent phenomenon affects the B lymphocyte compartment in SLE patients and T lymphocytes in ESKD-HD patients.

Correlation between peripheral blood lymphocyte subpopulations and primary systemic lupus erythematosus

This study explored the correlation between peripheral blood CD3^＋, CD3^＋/CD4^＋, CD3⁺/CD8⁺, CD4^＋/CD8^＋, CD3^-/CD16⁺ CD56⁺, and CD3^-CD19⁺ and disease activity of different subtypes of systemic lupus erythematosus (SLE). The percentages of CD3⁺, CD3⁺/CD4⁺, CD3⁺/CD8⁺, CD4⁺/CD8⁺, CD3^-/CD16⁺ CD56⁺, and CD3^-CD19⁺ in the peripheral blood of patients (n = 80) classified into lupus nephritis, blood involvement, and joint involvement and SLE in different active stages were detected by flow cytometry. Their correlations with baseline clinical experimental indicators of SLE patients' SLE disease activity index score (SLEDAI) and complement C3 were analyzed. The results showed that CD3⁺, CD3⁺/CD4⁺, and CD3⁺/CD8⁺ at baseline level were negatively correlated with SLEDAI scores. These were positively correlated with C3. In conclusion, T-lymphocyte subpopulations are closely related to SLE activity and can be used as reference indicators to evaluate the SLE activity.

Preclinical assessment of antigen-specific chimeric antigen receptor regulatory T cells for use in solid organ transplantation

A primary goal in transplantation medicine is the induction of a tolerogenic environment for prevention of transplant rejection without the need for long-term pharmacological immunosuppression. Generation of alloantigen-specific regulatory T cells (Tregs) by transduction with chimeric antigen receptors (CARs) is a promising strategy to achieve this goal. This publication reports the preclinical characterization of Tregs (TR101) transduced with a human leukocyte antigen (HLA)-A*02 CAR lentiviral vector (TX200) designated to induce immunosuppression of allograft-specific effector T cells in HLA-A*02-negative recipients of HLA-A*02-positive transplants. In vitro results demonstrated specificity, immunosuppressive function, and safety of TX200-TR101. In NOD scid gamma (NSG) mice, TX200-TR101 prevented graft-versus-host disease (GvHD) in a xenogeneic GvHD model and TX200-TR101 Tregs localized to human HLA-A*02-positive skin transplants in a transplant model. TX200-TR101 persisted over the entire duration of a 3-month study in humanized HLA-A*02 NSG mice and remained stable, without switching to a proinflammatory phenotype. Concomitant tacrolimus did not impair TX200-TR101 Treg survival or their ability to inhibit peripheral blood mononuclear cell (PBMC) engraftment. These data demonstrate that TX200-TR101 is specific, stable, efficacious, and safe in preclinical models, and provide the basis for a first-in-human study.

The Mango’s Mistletoe Leaves Extract Ameliorates Lupus by Inhibiting the Anti-dsDNA Antibody Production, the Percentages of CD8+CD28− and CD4+CD28− T Cells

BACKGROUND: In SLE patients, repeated antigen stimulations induce a progressive reduction in CD28 expression on the surface of T cells and the chronic inflammation condition. Mango’s mistletoe is a parasitic plant that has anti-inflammation, antiproliferation, and immunomodulatory activities. AIM: This study aimed to investigate the effect of mango’s mistletoe leaves extract (MLE) in inhibiting anti-dsDNA antibodies and ameliorating the percentages of CD8+CD28− and CD4+CD28− T cells in a pristane-induced lupus mice model. METHODS: Lupus induction was undertaken by an injection of pristane 0.5 ml intraperitoneally in 6–8-week-old female balb/c mice. Mice with lupus signs were grouped randomly into the treatment groups which received MLE at doses of 150, 300, and 600 mg/kgbw/d for 28 days, respectively, and the positive control group without MLE. On day 29, anti-dsDNA antibody levels were analyzed using an ELISA. One of the immunosenescence markers (CD28− T cells) was investigated using a flow cytometer. ANOVA test was used for statistical analysis. RESULTS: The mango’s mistletoe leaves extract (MLE) significantly decreased the number of anti-dsDNA antibodies (*p < 0.05), the percentages of CD8+CD28− T cells (*p < 0.05) and CD4+CD28− T cells (*p < 0.05). CONCLUSION: We resume that the mango’s mistletoe leaves can ameliorate lupus by inhibiting anti-dsDNA antibody production and the percentages of CD8+CD28− and CD4+CD28− T cells.