Increased Spontaneous Ex Vivo Apoptosis and Subset Alterations in Peripheral Blood T Cells from Patients with Multiple Sclerosis

Pathway analysis of peripheral blood CD8+ T cell transcriptome shows differential regulation of sphingolipid signaling in multiple sclerosis and glioblastoma

Multiple sclerosis (MS) and glioblastoma (GBM) are CNS diseases in whose development and progression immune privilege is intimately important, but in a relatively opposite manner. Maintenance and strengthening of immune privilege have been shown to be an important mechanism in glioblastoma immune evasion, while the breakdown of immune privilege leads to MS initiation and exacerbation. We hypothesize that molecular signaling pathways can be oppositely regulated in peripheral blood CD8+ T cells of MS and glioblastoma patients at a transcriptional level. We analyzed publicly available data of the peripheral blood CD8+ T cell MS vs. control (MSvsCTRL) and GBM vs. control (GBMvsCTRL) differentially expressed gene (DEG) contrasts with Qiagen's Ingenuity pathway analysis software (IPA). We have identified sphingolipid signaling pathway which was significantly downregulated in the GBMvsCTRL and upregulated in the MSvsCTRL. As the pathway is important for the CD8+ T lymphocytes CNS infiltration, this result is in line with our previously stated hypothesis. Comparing publicly available lists of differentially expressed serum exosomal miRNAs from MSvsCTRL and GBMvsCTRL contrasts, we have identified that hsa-miR-182-5p has the greatest potential effect on sphingolipid signaling regarding the number of regulated DEGs in the GBMvsCTRL contrast, while not being able to find any relevant potential sphingolipid signaling target transcripts in the MSvsCTRL contrast. We conclude that the sphingolipid signaling pathway is a top oppositely regulated pathway in peripheral blood CD8+ T cells from GBM and MS, and might be crucial for the differences in CNS immune privilege maintenance of investigated diseases, but further experimental research is necessary.

Multiple sclerosis endophenotypes identified by high-dimensional blood signatures are associated with distinct disease trajectories

One of the biggest challenges in managing multiple sclerosis is the heterogeneity of clinical manifestations and progression trajectories. It still remains to be elucidated whether this heterogeneity is reflected by discrete immune signatures in the blood as a surrogate of disease pathophysiology. Accordingly, individualized treatment selection based on immunobiological principles is still not feasible. Using two independent multicentric longitudinal cohorts of patients with early multiple sclerosis (n = 309 discovery and n = 232 validation), we were able to identify three distinct peripheral blood immunological endophenotypes by a combination of high-dimensional flow cytometry and serum proteomics, followed by unsupervised clustering. Longitudinal clinical and paraclinical follow-up data collected for the cohorts revealed that these endophenotypes were associated with disease trajectories of inflammation versus early structural damage. Investigating the capacity of immunotherapies to normalize endophenotype-specific immune signatures revealed discrete effect sizes as illustrated by the limited effect of interferon-β on endophenotype 3-related immune signatures. Accordingly, patients who fell into endophenotype 3 subsequently treated with interferon-β exhibited higher disease progression and MRI activity over a 4-year follow-up compared with treatment with other therapies. We therefore propose that ascertaining a patient's blood immune signature before immunomodulatory treatment initiation may facilitate prediction of clinical disease trajectories and enable personalized treatment decisions based on pathobiological principles.

Sex-related Differences in Inflammatory Bowel Diseases: The Potential Role of Sex Hormones

Inflammatory bowel disease (IBD), characterized by chronic inflammation of the gastrointestinal tract, is a global health care problem. Compelling evidence shows sex differences regarding the prevalence, pathophysiology, clinical presentation, and treatment outcome of IBD. Sex hormones, including estrogen, progesterone, and androgen, have been proposed to have a role in the pathogenesis of sexual dimorphism in IBD. Clinical and experimental data support the modulatory effects of sex hormones on various clinical characteristics of the disease, including intestinal barrier dysfunction and mucosal immune activation. Additionally, the potential role of sex hormones in the modulation of gut microbiota is attracting increasing attention. Here, we discuss the sex dimorphic disease profile and address the potential mechanisms involved in the sex-specific pathogenesis of IBD. Improved understanding of these sex differences in the clinic could improve the knowledge of patients with IBD with heterogeneous disease profiles.

Mesenchymal adipose stem cells maintain the capacity for differentiation and survival in culture beyond the long term

Mesenchymal cells (MSCs) are considered to be cellular populations of common embryological origin. For clinical research applications, MSCs are expanded and increased with cells obtained from a primary culture. By extracting cells from tissue and encouraging them to reproduce, the stem cell population ends up dominating the culture due to a high proliferation rate and self-renewal. The first subcultures between the third and sixth are chosen in order to obtain the maximum number of cells with optimal differentiation capacity. However, few studies have reported long-term cultivation of MSCs. The objective of this study was to advance the knowledge on the characteristics of MSCs by assessing their capacity for self-renewal and phenotypic maintenance beyond 50 cell subcultures, which is defined as the normal limit for cellular survival. Rat subcutaneous adipose tissue was the source of mesenchymal adipose stem cells (MASCs) cultured over 175 subcultures. Early 1 to 5 and late 25 to 30 subcultures were used to induce cellular differentiation to become adipogenic, chondrogenic and osteogenic connective tissue cells. MASCs characteristics were studied using flow cytometry, transmission electron microscopy (TEM), and immunohistochemical and reverse transcription polymerase chain reaction (RT-qPCR) assays. The MASCs maintained cell differentiation capacity for more than 30 subcultures but lost potentiality starting at 60 up to 175 subcultures. MASCs showed the embryonic phenotypes OCT3/4 and Nanog indefinitely, and developed compensatory mechanisms, such as autophagy, to achieve cell survival over a long time period. Therefore, long-term subcultures showed that MASCs could maintain their potential for clinical research use.

The effect of estrogen in coronavirus disease 2019

The outcomes of coronavirus disease 2019 (COVID-19) vary between men and women. Some statistical reports have shown that men have a higher risk of developing COVID-19 and suffer from worse outcomes than females. Although there are many factors that can explain the high prevalence of COVID-19 in men, such as lifestyle habits and the different profile of comorbidities among sexes, the distinctions between male and female immune systems cannot be ignored. It has been sufficiently shown that sex differences have a critical influence on the shaping of immune response, which then leads to different pathogenesis in infectious diseases. Compared with males, females typically have a more effective innate and adaptive immune response to viral infections in COVID-19. What's more, there is a growing body of evidence showing that estrogen exerts an effect on the regulation of immune response. This article examines the effect and mechanism of estrogen on COVID-19.

Impact of sex hormones on immune function and multiple sclerosis development

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) affecting young people and leading to demyelination and neurodegeneration. The disease is clearly more common in women, in whom incidence has been rising. Gender differences include: earlier disease onset and more frequent relapses in women; and faster progression and worse outcomes in men. Hormone-related physiological conditions in women such as puberty, pregnancy, puerperium, and menopause also exert significant influence both on disease prevalence as well as on outcomes. Hormonal and/or genetic factors are therefore believed to be involved in regulating the course of disease. In this review, we discuss clinical evidence for the impact of sex hormones (estrogens, progesterone, prolactin, and testosterone) on MS and attempt to elucidate the hormonal and immunological mechanisms potentially underlying these changes. We also review current knowledge on the relationship between sex hormones and resident CNS cells and provide new insights in the context of MS. Understanding these molecular mechanisms may contribute to the development of new and safer treatments for both men and women.

Abnormal chemokine receptor profile on circulating T lymphocytes from nonallergic asthma patients

BACKGROUND

T lymphocytes are involved in the pathogenesis of nonallergic asthma. The objective of this study was to characterize the subset distribution and pattern of chemokine receptor expression in circulating T lymphocyte subsets from nonallergic asthma patients.

METHODS

Forty stable nonallergic asthma patients and 16 sex- and age-matched healthy donors were studied. Twelve patients did not receive inhaled steroids (untreated patients), 16 received 50-500 μg b.i.d. of inhaled fluticasone propionate (FP) (standard-dose patients), and 12 received over 500 μg b.i.d. of inhaled FP (high-dose patients) for at least 12 months prior to the beginning of this study and were clinically well controlled. Flow cytometry was performed using a panel of monoclonal antibodies (4 colors).

RESULTS

Nonallergic asthma patients treated with high doses of inhaled FP showed a significant reduction in the percentages of CD3+ T lymphocytes compared to healthy controls. Untreated patients showed a significant increase in CCR6 expression in CD8+CD25+ and CD8+CD25+bright T cells compared to healthy controls. The results were similar for CXCR3 and CCR5 expression. In patients treated with standard doses of FP, CCR5 expression was significantly increased in CD3+ T lymphocytes relative to healthy controls.

CONCLUSIONS

The different groups of clinically stable nonallergic asthmatic patients showed distinct patterns of alterations in subset distribution as well as CCR6, CXCR3, and CCR5 expression on circulating T lymphocytes. .

Activation-induced cell death in T lymphocytes from multiple sclerosis patients

Apoptosis is a major mechanism regulating immune tolerance by the elimination of autoreactive T lymphocytes. A failure of activation induced cell-death (AICD) has been described in T lymphocytes from patients with multiple sclerosis (MS). The aims of this study were to evaluate AICD in T lymphocytes from patients with MS and healthy controls, and to explore the molecular mechanisms underlying the deregulation observed in apoptosis induction. PHA-induced AICD was reduced in T lymphocytes from patients with relapsing-remitting MS compared with controls. This finding was associated with a diminished expression of Fas and a failure in caspase 3 activation.

Search for cellular stress biomarkers in lymphocytes from patients with multiple sclerosis: a pilot study

Multiple Sclerosis (MS) is a chronic disease of the central nervous system, the etiology of which, although not completely known, involves inflammation and autoimmunity. In the present study we aimed at identifying molecular markers of apoptosis, cellular stress and DNA damage in isolated peripheral blood mononuclear cells (PBMCs) of MS patients. The analysis was carried on 19 relapsing-remitting untreated MS patients and 13 healthy individuals. We investigated the emergency-driven synthesis of poly(ADP-ribose) (PAR), the expression level of the constitutive enzyme poly(ADP-ribose) polymerase-1 (PARP-1) and the DNA damage-induced phosphorylation of histone H2AX. PAR accumulation, PARP-1 and phosphorylated H2AX (γH2AX) were detected by immunofluorescence experiments on PBMCs isolated from 19 patients and 13 healthy volunteers. Our results show for the first time a net increased amount in PAR and γH2AX in MS patients compared to healthy individuals. Patients were further subdivided in three groups, according to the neuroimaging (MRI)-based classification of disease phase. Remarkably, we found a positive correlation between the level of γH2AX and MS aggressiveness. In addition, apoptosis in PBMCs was monitored by flow cytometry of both phosphatidylserine exposure (revealed by Annexin V-FITC labeling) and membrane permeability to propidium iodide. Our observations provide the evidence that the number of apoptotic cells was significantly higher in patients compared to healthy individuals, thus suggesting that apoptosis could affect MS lymphocyte function.

Risk of cataract and glaucoma in patients with multiple sclerosis

BACKGROUND

The aim of the study was to evaluate whether multiple sclerosis (MS) is associated with risk of cataract or glaucoma.

METHODS

We conducted a population-based cohort study utilizing the UK General Practice Research Database (1987-2009) linked to the national hospital registry of England (1997-2008). Incident MS patients (5576 cases) were identified and each was matched to six patients without MS (controls) by age, gender, and practice. Cox proportional hazard models were used to estimate hazard ratios (HRs) of incident cataract and glaucoma in MS. Time-dependent adjustments were made for age, history of diseases and drug use.

RESULTS

MS patients had no overall increased risk of cataract, adjusted (adj.) HR 1.15 (95% CI 0.94-1.41) or glaucoma, adj. HR 1.02 (95% CI 0.78-1.33). Risk of cataract (adj. HR 2.45 (95% CI 1.56-3.86)) and glaucoma (adj. HR 1.70 (95% CI 1.01-2.86)) was significantly greater in patients < 50 years, particularly in men < 50 years: cataract, adj. HR 4.23 (95% CI 2.22-8.05) and glaucoma, adj. HR 2.76 (95% CI 1.28-5.93).

CONCLUSION

This is the first study which showed that the risk of cataract and glaucoma is elevated in MS patients younger than 50 years, particularly men.

Inhaled IL-2 induces systemic immunomodulation in patients with renal cell carcinoma and lung metastasis

The peripheral blood lymphocytes of eight patients with metastatic renal cell carcinoma, and of eight healthy volunteers were analyzed by four-color flow cytometry to characterize the immunophenotypic alterations manifested, determine the prevalence of lymphocyte apoptosis, and detect evidence of the systemic effect of inhaled IL-2. The T, B and NK lymphocytes of untreated patients were found to have undergone profound changes characterized by an increase in susceptibility to both spontaneous and mitogen-induced ex vivo apoptosis, a modified distribution of the main lymphocyte populations in the peripheral blood, and alterations in activation status. An increase in the proportion of regulatory T cells was also seen in these patients. Treatment with inhaled IL-2, however, normalized the rate of apoptosis in all the lymphocyte subpopulations studied, as well as their distribution and activation status. These findings demonstrate that inhaled IL-2 has systemic immunomodulatory effects.

The involvement of mitochondria in the pathogenesis of multiple sclerosis

Multiple sclerosis is an immune-mediated disorder of the central nervous system. Major pathological characteristics include the loss of oligodendrocytes, demyelination and neuroaxonal depletion in association with inflammation. The complex pathophysiology of tissue loss is only partially understood. Here we discuss a variety of mitochondrion-driven mechanisms involved in immune regulation, oligodendrocyte depletion and neurodegeneration. The recognition of a mitochondrial link between inflammation and neurodegeneration underscores the importance of an early aggressive intervention for halting inflammation and preventing neurodegeneration, and identifies the mitochondrion as a potential target in neuroprotection.

CD4(+) memory T cells with high CD26 surface expression are enriched for Th1 markers and correlate with clinical severity of multiple sclerosis

An aberrant immune activation is believed to be important in the pathogenesis of multiple sclerosis (MS). Expression of CD4(+) T lymphocyte surface molecules indicative of immune activation and effector functions has been correlated with disease severity and activity. CD4(+) CD45R0(+) CD26(high) memory T lymphocytes contained the high levels of markers of Th1, activation, and effector functions and cell counts of this subset correlated with MS disease severity. This subset had lower expression of PD-1, CCR4, and L-selectin in MS than in controls. These changes were only partially normalised by treatment with interferon-beta. We point to this subset as a putative target for immunological monitoring of MS disease activity and of treatment efficacy.