IL-2 as a therapeutic target for the restoration of Foxp3+ regulatory T cell function in organ-specific autoimmunity: implications in pathophysiology and translation to human disease

Efficacy of substances containing 3 types of active ingredients-saponins, flavones, and alkaloids in regulation of cytokines in autoimmune diseases a systematic review and Meta-analysis based on animal studies

OBJECTIVE

To investigate the efficacy of substances containing 3 types of active ingredients-saponins, flavones, and alkaloids on experimental animals with autoimmune diseases (AIDs).

METHODS

The protocol for this systematic review and Meta-analysis was prospectively registered with PROSPERO (CRD42023395741). Searches were conducted in the China National Knowledge Infrastructure, Wanfang, Chinese Science and Technology Journals, China Biomedical, PubMed, Cochrane Library, and Embase databases to screen for animal studies investigating the therapeutic effects of saponins, flavones, or alkaloids on autoimmune diseases; consequently, corresponding data extraction tables were prepared. Systematic Review Centre for Laboratory Animal Experimentation was used to assess the risk of methodological bias in the included literature. RevMan 5.4 was used for the Meta-analysis on the 8 serum cytokines.

RESULTS

A total of 31 studies were included, all of which were randomized controlled studies. Meta-analysis indicated that substances rich in saponins, flavones, and alkaloids reduced serum levels of interleukin (IL)-1β [standardized mean difference (SMD) = -1.94, 95% confidence interval (CI) (-2.99, -0.90), P = 0.0003], IL-6 [SMD = -1.65, 95% CI (-2.33, -0.97,) P < 0.000 01], IL-17 [SMD = -2.41, 95% CI (-3.61, -1.20), P < 0.0001], tumor necrosis factor (TNF)-α [SMD = -1.84, 95% CI (-2.61, -1.06), P < 0.0001], and interferon (IFN)-γ [SMD = -1.54, 95% CI (-2.43, -0.65), P = 0.0007], but increased serum levels of IL-4 [SMD = 1.30, 95% CI (0.15, 2.44), P = 0.03) and IL-10 [SMD = 2.05, 95% CI (1.39, 2.70), P < 0.000 01) in animal models. However, no significant regulatory effect of these three active components was observed on serum levels of IL-2 [SMD = -0.63, 95% CI (-1.82, 0.57), P = 0.30].

CONCLUTIONS

Substances containing saponins, flavones, and alkaloids regulated the changes of immune-related cytokines, it may be a novel dietary substance to relieve and control autoimmune diseases in the future.

Review on Monoclonal Antibodies (mAbs) as a Therapeutic Approach for Type 1 Diabetes

Monoclonal antibodies have been successfully utilized in a variety of animal models to treat auto-immune illnesses for a long time. Immune system responses will either be less active or more active depending on how the immune system is operating abnormally. Immune system hypoactivity reduces the body's capacity to fight off various invading pathogens, whereas immune system hyperactivity causes the body to attack and kill its own tissues and cells. For maximal patient compliance, we will concentrate on a variety of antibody therapies in this study to treat Type 1 diabetes (an autoimmune condition). T-cells are responsible for the auto-immune condition known as T1D, which causes irregularities in the function of β-cells in the pancreas. As a result, for the treatment and prevention of T1D, immunotherapies that selectively restore continuous beta cellspecific self-tolerance are needed. Utilizing monoclonal antibodies is one way to specifically target immune cell populations responsible for the auto-immune-driven disease (mAb). Numerous mAbs have demonstrated clinical safety and varied degrees of success in modulating autoimmunity, including T1D. A targeted cell population is exhausted by mAb treatments, regardless of antigenic specificity. One drawback of this treatment is the loss of obtained protective immunity. Immune effector cell function is regulated by nondepleting monoclonal antibodies (mAb). The antigenfocused new drug delivery system is made possible by the adaptability of mAbs. For the treatment of T1D and T-cell-mediated autoimmunity, different existing and potential mAb therapy methods are described in this article.

Regulatory T Cell Plasticity and Stability and Autoimmune Diseases

CD4⁺CD25⁺ regulatory T cells (Tregs) are a class of CD4⁺ T cells with immunosuppressive functions that play a critical role in maintaining immune homeostasis. However, in certain disease settings, Tregs demonstrate plastic differentiation, and the stability of these Tregs, which is characterized by the stable expression or protective epigenetic modifications of the transcription factor Foxp3, becomes abnormal. Plastic Tregs have some features of helper T (Th) cells, such as the secretion of Th-related cytokines and the expression of specific transcription factors in Th cells, but also still retain the expression of Foxp3, a feature of Tregs. Although such Th-like Tregs can secrete pro-inflammatory cytokines, they still possess a strong ability to inhibit specific Th cell responses. Therefore, the plastic differentiation of Tregs not only increases the complexity of the immune circumstances under pathological conditions, especially autoimmune diseases, but also shows an association with changes in the stability of Tregs. The plastic differentiation and stability change of Tregs play vital roles in the progression of diseases. This review focuses on the phenotypic characteristics, functions, and formation conditions of several plastic Tregs and also summarizes the changes of Treg stability and their effects on inhibitory function. Additionally, the effects of Treg plasticity and stability on disease prognosis for several autoimmune diseases were also investigated in order to better understand the relationship between Tregs and autoimmune diseases.

Autoimmune hepatitis association with single nucleotide polymorphism of interleukin-2, but not interferon-gamma

BACKGROUND

Autoimmune hepatitis (AIH) is a chronic inflammation in hepatocellular tissues associated with circulating autoantibodies. Imbalance in T-cells population and dysregulation in several cytokine profiles has been implicated in pathogenesis of AIH. This study was performed to assess potential association of AIH with interleukin-2 (IL-2) and interferon-gamma (IFN-γ) genes single nucleotide polymorphisms (SNPs).

METHODS

Fifty-six patients with AIH and 139 healthy individuals were enrolled in this study. IL-2 and IFN-γ typing was performed, using polymerase chain reaction with sequence-specific primers (PCR-SSP) assay. The frequencies of alleles, genotypes and haplotypes in AIH patients were compared to healthy controls.

RESULTS

IL-2 T allele at position +166 (rs2069763) showed significant higher frequency in AIH group (36%), compared to the controls (21%) (OR=2.06; 95% CI, 1.24-3.43, P-value<0.01). The frequency of IL-2 TT genotype at +166 position was also associated with AIH (OR=18.68, 95% CI 3.74-126.04, P-value<0.01). G/T alleles of IL-2 at -330 (rs2069762) and A/T alleles on UTR +5644 position at IFN-γ and their subsequent haplotypes, did not show significant association with AIH.

CONCLUSIONS

This study identified IL-2T allele at +166 position and TT genotype as susceptibility gene in AIH which would provide better understandings into the mechanisms of AIH and potential immune modulation therapies.

Deficiencies of the T and natural killer cell system in major depressive disorder: T regulatory cell defects are associated with inflammatory monocyte activation

BACKGROUND

In a previous study, we found an up-regulated inflammatory monocyte gene expression profile in major depressive disorder (MDD) patients aged ⩾ 28 years and a down-regulated inflammatory gene expression profile in MDD patients aged<28 years. In the same sample of patients, we aimed to investigate immune dysregulation in the lymphocyte arm of the immune system, particularly in the context of the described monocyte (de-)activation states.

METHODS

From deep frozen leukocytes, circulating percentages of monocytes, lymphocytes, B, T, and natural killer (NK) cells, and various functional subsets of T and T helper (Th) cells (Th1, Th2, Th17, and natural T regulatory cells) were measured in N=50 MDD patients and N=58 age- and gender-matched healthy controls (HC). In addition, serum levels of interleukin (IL)-6, sCD25, IL-7, IL-3, SCF, IGF-BP2, and EGF were evaluated.

RESULTS

MDD patients were in general characterized by an impaired maturation of Th2 cells, Th17 cells, and NK cells and by decreased serum levels of IL-7 and sCD25. MDD patients aged ⩾ 28 years additionally exhibited decreased percentages of CD4(+)CD25(high)FoxP3(+) T regulatory cells, next to signs of the above described partial T cell defects. Natural T regulatory cells were inversely associated with the pro-inflammatory state of the monocytes (r=-.311; p=.034) that characterized this patient subgroup.

CONCLUSIONS

Deficiencies of the NK and T (regulatory) cell system and inflammatory monocyte immune activation co-occur as partly interrelated phenomena within the same MDD patients.

Ameliorative effect of supplementation with L-glutamine on oxidative stress, DNA damage, cell viability and hepatotoxicity induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in rat hepatocyte cultures

The most potent of the dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), is a persistent and ubiquitous environmental contaminant. And the health impact of exposure to TCDD is of great concern to the general public. Recent data indicate that L-glutamine (Gln) has antioxidant properties and may influence hepatotoxicity. The objective of the present study was undertaken to explore the effectiveness of Gln in alleviating the hepatotoxicity of TCDD on primary cultured rat hepatocytes. Gln (0.5, 1 and 2 mM) was added to cultures alone or simultaneously with TCDD (0.005 and 0.01 mM). The hepatocytes were treated with TCDD and Gln for 48 h. Then cell viability was detected by [3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide] (MTT) assay and lactate dehydrogenase (LDH) release, while total antioxidant capacity (TAC), total glutathione (TGSH) and total oxidative stress (TOS) levels were determined to evaluate the oxidative injury. The DNA damage was also analyzed by liver micronucleus assay (MN) and 8-oxo-2-deoxyguanosine (8-OH-dG). The results of MTT and LDH assays showed that TCDD decreased cell viability but not L-glutamine. TCDD also increased TOS level in rat hepatocytes and significantly decreased TAC and TGSH levels. On the basis of increasing doses, the dioxin in a dose-dependent manner caused significant increases of micronucleated hepatocytes (MNHEPs) and 8-OH-dG as compared to control culture. Whereas, in cultures exposured with Gln alone, TOS levels were not changed and TAC and TGSH together were significantly increased in dose-dependent fashion. The presence of Gln with TCDD modulated the hepatotoxic effects of TCDD on primary hepatocytes cultures. Noteworthy, Gln has a protective effect against TCDD-mediated DNA damages. As conclusion, we reported here an increased potential therapeutic significance of L-glutamine in TCDD-mediated hepatic injury for the first time.

Functional stability of Foxp3+ regulatory T cells

Significant evidence demonstrates that CD4(+) regulatory T cells (T(reg)) expressing the Forkhead box P3 (Foxp3) transcription factor are a distinct lineage of CD4(+) T cells that are essential for maintaining self-tolerance and modulating immunity to various nonself-antigens under changing inflammatory settings. Stable Foxp3 expression ensures T(reg) function in a variety of inflammatory contexts. However, the model of T(reg) cells as a stable, long-lived lineage is controversial. Whereas some studies have observed long-lived T(reg) function, recent studies suggest that T(reg) cells adapt to microenvironmental changes and consequently manifest functional plasticity by reprogramming into inflammatory T cells. Here, we review the evidence addressing the functional stability or plasticity of Foxp3(+) T(reg) cells and the implications for immune homeostasis and disease.

Sequential administration of GM-CSF and IL-2 surface-modified MB49 cells vaccines against the metastatic bladder cancer

OBJECTIVES

Many strategies are pursued to enhance tumor vaccine immune response, including the utilization of cytokines. We have developed a novel protein-anchor technology to immobilize cytokines on tumor cell surface. Here we reported the preparation of tumor cell vaccines by immobilizing GM-CSF or IL-2 on MB49 bladder cancer cells and evaluated their antitumor efficacy (administrated alone or sequentially) in a metastatic mouse model.

MATERIALS AND METHODS

SA-mGM-CSF or SA-hIL-2 surface-modified MB49 cells were prepared as vaccine. Mice were treated with MB49 cell vaccines (administrated alone or sequentially). Survival time, tumor growth, flow cytometry, immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), and cytotoxic T lymphocytes (CTL) assay were used to evaluate the antitumor efficiency of the vaccines in the pulmonary metastatic model of bladder cancer.

RESULTS

GM-CSF vaccine induced more mature dendritic cells in the mice spleen. Combination with subsequent IL-2 vaccine significantly increased CD4(+), CD8(+), and IFN-γ(+)CD8(+) T but not CD4(+)Foxp3(+) T cell population and induced the highest production of IFN-γ, IL-12, but not IL-10. Furthermore, the splenocytes from the sequentially combined vaccines group showed the most potent cytotoxicity on MB49 cells. Finally, the sequentially combined vaccines evidently extended the survival time of mice (the median survival time of PBS, ethanol-fixed, anchored GM-CSF, anchored IL-2, and anchored GM-CSF + anchored IL-2 groups were 34, 37, 45, 47, and 59 days, respectively) and effectively protected the mice against a second MB49 cells but not RM-1 cells challenge.

CONCLUSIONS

This study demonstrated that sequential administration of GM-CSF and IL-2 surface-modified MB49 cells vaccines could effectively induce specific antitumor immune response.

Lotus (Nelumbo nucifera Gaertn) plumule polysaccharide protects the spleen and liver from spontaneous inflammation in non-obese diabetic mice by modulating pro-/anti-inflammatory cytokine gene expression

A novel lotus plumule polysaccharide (LPPS) was administered to non-obese diabetic (NOD) mice for 15weeks to evaluate the protective effects of LPPS on type 1 diabetes. After the 15-week feeding experiment, tumour necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10 expressions in the spleen, liver and kidney of the experimental mice were measured using enzyme-linked immunosorbent assay or real-time quantitative polymerase chain reaction assay. The results showed that LPPS significantly (p<0.05) decreased the absolute weights of the enlarged spleens in the NOD mice in a dose-dependent manner, inhibited pro-inflammatory TNF-α and IL-6 cytokine production and decreased the secretion ratio of IL-6/IL-10 in splenocyte cultures. LPPS markedly decreased the relative expression of pro-/anti-inflammatory cytokine genes (TNF-α/IL-10 and IL-6/IL-10) in the livers of NOD mice. Our results suggest that LPPS protected the spleen and liver from spontaneous inflammation in NOD mice by modulating pro-/anti-inflammatory cytokine gene expression.