The CD4+ T-cell subset lacking expression of the CD28 costimulatory molecule is expanded and shows a higher activation state in multiple sclerosis

The association between various viral infections and multiple sclerosis: An umbrella review on systematic review and meta-analysis

Multiple Sclerosis (MS) is one of the immune-mediated demyelinating disorders. Multiple components, including the environment and genetics, are possible factors in the pathogenesis of MS. Also, it can be said that infections are a key component of the host's response to MS development. Finally, we evaluated the relationship between different pathogens and MS disease in this umbrella research. We systematically collected and analysed multiple meta-analyses focused on one particular topic. We utilised the Scopus, PubMed, and Web of Science databases starting with inception until 30 May 2023. The methodological quality of the analysed meta-analysis has been determined based on Assessing the Methodological Quality of Systematic Reviews 2 and Grade, and graph construction and statistical analysis were conducted using Comprehensive Meta-Analysis. The Confidence Interval of effect size was 95% in meta-analyses, and p < 0.05 indicated a statistically meaningful relationship. The included studies evaluated the association between MS and 12 viruses containing SARS-CoV-2, Epstein-Barr virus (EBV), Hepatitis B virus, varicella-zoster virus (VZV), human herpesvirus 6 (HHV-6), HHV-7, HHV-8, HSV-1, HSV-2, Cytomegalovirus, Human Papillomavirus, and influenza. SARS-CoV-2, with a 3.74 odds ratio, has a significantly more potent negative effect on MS among viral infections. After that, EBV, HHV-6, HSV-2, and VZV, respectively, with 3.33, 2.81, 1.76, and 1.72 odds ratios, had a significantly negative relationship with MS (p < 0.05). Although the theoretical evidence mostly indicates that EBV has the greatest effect on MS, recent epidemiological studies have challenged this conclusion and put forward possibilities that SARS-CoV-2 is the culprit. Hence, it was necessary to investigate the effects of SARS-CoV-2 and EBV on MS.

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.

Treg-Resistant Cytotoxic CD4+ T Cells Dictate T Helper Cells in Their Vicinity: TH17 Skewing and Modulation of Proliferation

Cytotoxic CD4⁺ T cells (CD4 CTL) are terminally differentiated T helper cells that contribute to autoimmune diseases, such as multiple sclerosis. We developed a novel triple co-culture transwell assay to study mutual interactions between CD4 CTL, conventional TH cells, and regulatory T cells (Tregs) simultaneously. We show that, while CD4 CTL are resistant to suppression by Tregs in vitro, the conditioned medium of CD4 CTL accentuates the suppressive phenotype of Tregs by upregulating IL-10, Granzyme B, CTLA-4, and PD-1. We demonstrate that CD4 CTL conditioned medium skews memory TH cells to a TH17 phenotype, suggesting that the CD4 CTL induce bystander polarization. In our triple co-culture assay, the CD4 CTL secretome promotes the proliferation of TH cells, even in the presence of Tregs. However, when cell−cell contact is established between CD4 CTL and TH cells, the proliferation of TH cells is no longer increased and Treg-mediated suppression is restored. Taken together, our results suggest that when TH cells acquire cytotoxic properties, these Treg-resistant CD4 CTL affect the proliferation and phenotype of conventional TH cells in their vicinity. By creating such a pro-inflammatory microenvironment, CD4 CTL may favor their own persistence and expansion, and that of other potentially pathogenic TH cells, thereby contributing to pathogenic responses in autoimmune disorders.

Inclusion body myositis: clinical features and pathogenesis

Inclusion body myositis (IBM) is often viewed as an enigmatic disease with uncertain pathogenic mechanisms and confusion around diagnosis, classification and prospects for treatment. Its clinical features (finger flexor and quadriceps weakness) and pathological features (invasion of myofibres by cytotoxic T cells) are unique among muscle diseases. Although IBM T cell autoimmunity has long been recognized, enormous attention has been focused for decades on several biomarkers of myofibre protein aggregates, which are present in <1% of myofibres in patients with IBM. This focus has given rise, together with the relative treatment refractoriness of IBM, to a competing view that IBM is not an autoimmune disease. Findings from the past decade that implicate autoimmunity in IBM include the identification of a circulating autoantibody (anti-cN1A); the absence of any statistically significant genetic risk factor other than the common autoimmune disease 8.1 MHC haplotype in whole-genome sequencing studies; the presence of a marked cytotoxic T cell signature in gene expression studies; and the identification in muscle and blood of large populations of clonal highly differentiated cytotoxic CD8⁺ T cells that are resistant to many immunotherapies. Mounting evidence that IBM is an autoimmune T cell-mediated disease provides hope that future therapies directed towards depleting these cells could be effective.

Characterization of naïve, memory and effector T cells in progressive multiple sclerosis

We characterized naïve, central memory (CM), effector memory (EM) and terminally differentiated effector memory (TEMRA) CD4⁺ and CD8⁺ T cells and their expression of CD49d and CD26 in peripheral blood in patients with multiple sclerosis (MS) and healthy controls. CD26⁺ CD28⁺ CD4⁺ TEMRA T cells were increased in all subtypes of MS, and CD26⁺ CD28⁺ CD8⁺ TEMRA T cells were increased in relapsing-remitting and secondary progressive MS. Conversely, in progressive MS, CD49d⁺ CM T cells were decreased and natalizumab increased the circulating number of all six subsets but reduced the frequency of most subsets expressing CD49d and CD26.

Murine Cytomegalovirus Infection Induces Susceptibility to EAE in Resistant BALB/c Mice

In contrast to C57BL/6 mice, BALB/c mice are relatively resistant to the induction of experimental autoimmune encephalomyelitis (EAE) after challenge with MOG_35–55 peptide. Here, we provide the first evidence that infection with murine cytomegalovirus (MCMV) in adulthood abrogates this resistance. Infected BALB/c mice developed clinical and histological signs similar to those seen in susceptible C57BL/6 mice. In addition to CD4⁺ cells, large proportion of cells in the infiltrate of diseased BALB/c mice was CD8⁺, similar with findings in multiple sclerosis. CD8⁺ cells that responded to ex vivo restimulation with MOG_35–55 were not specific for viral epitopes pp89 and m164. MCMV infection favors proinflammatory type of dendritic cells (CD86⁺CD40⁺CD11c⁺) in the peripheral lymph organs, M1 type of microglia in central nervous system, and increases development of Th1/Th17 encephalitogenic cells. This study indicates that MCMV may enhance autoimmune neuropathology and abrogate inherent resistance to EAE in mouse strain by enhancing proinflammatory phenotype of antigen-presenting cells, Th1/Th17, and CD8 response to MOG_35–55.

Characterization and clinical relevance of circulating CD4+CD28- T cells in Graves' disease

During autoimmune disease the fraction of CD4+CD28- T cells in the peripheral blood of has been found to be elevated. In the present study, peripheral blood was collected from 61 patients with Graves' disease (GD) and 30 healthy control participants. Serum concentrations of thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4) and thyrotropin receptor autoantibody (TRAb) were measured and peripheral blood mononuclear cell (PBMC) surface expression of CD4 and CD28 molecules was detected by flow cytometry. CD4+CD28- cells were sorted from six patients undergoing subtotal thyroidectomy and cultured ex vivo. The influence of TSH pretreated thyroid follicular cells on CD4+CD28- cell proliferation was evaluated using the agonist CD40 mAb 5C11, the blocking CD40L mAb 4F1 or B7-1 mAb 4E5 in 3H-TdR assays. Our data showed that the fraction of CD4+CD28- T cells was higher in GD patients than healthy donors (10.21%±8.56% vs. 2.33%±1.94%; P<0.001), and further elevated in 24 of 61 patients with Graves' ophthalmopathy (GO) (7.00±6.57% vs. 15.21±8.96%; P<0.001). A higher proportion of CD4+CD28- cells was detected in patients with degree II or III goiter than those with degree I goiter (11.53±9.18% vs. 6.11±3.97%; P<0.05 and 14.50±10.41% vs. 6.11±3.97%; P<0.01). The percentage of CD4+CD28- T cells correlated positively with serum levels of FT3 (r=0.354, P<0.01) and TRAb (r=0.304, P<0.05), but did not correlate with serum FT4 or TSH. Ex vivo, 5C11 enhanced proliferation of CD4+CD28+ cells (P<0.05), but did not influence the proliferation of CD4+CD28- cells. 4F1 inhibited the proliferation of both CD4+CD28+ (P<0.05) and CD4+CD28- (P<0.01) cells, and 4E5 inhibited proliferation of CD4+CD28+ cells (P<0.05). The elevation in circulating CD4+CD28- cells in GD patients correlates with disease severity and maybe plays an important role in the pathogenesis of GD.

The story of CD4+ CD28- T cells revisited: solved or still ongoing?

CD4⁺CD28⁻ T cells are a unique type of proinflammatory T cells characterised by blockade of costimulatory CD28 receptor expression at the transcriptional level, which is still reversible by IL-12. In healthy individuals older than 65 years, these cells may accumulate to up to 50% of total CD4⁺ T lymphocytes as in many immune-mediated diseases, immunodeficiency, and specific infectious diseases. Here we focus on CD4⁺CD28⁻ T cells in chronic immune-mediated diseases, summarizing various phenotypic and functional characteristics, which vary depending on the underlying disease, disease activity, and concurrent treatment. CD4⁺CD28⁻ T cells present as effector/memory cells with increased replicative history and oligoclonality but reduced apoptosis. As an alternative costimulatory signal instead of CD28, not only natural killer cell receptors and Toll-like receptors, but also CD47, CTLA-4, OX40, and 4-1BB have to be considered. The proinflammatory and cytotoxic capacities of these cells indicate an involvement in progression and maintenance of chronic immune-mediated disease. So far it has been shown that treatment with TNF-α blockers, abatacept, statins, and polyclonal antilymphocyte globulins (ATG) mediates reduction of the CD4⁺CD28⁻ T cell level. The clinical relevance of targeting CD4⁺CD28⁻ T cells as a therapeutic option has not been examined so far.

Presence of the full-length KIR2DS4 gene reduces the chance of rheumatoid arthritis patients to respond to methotrexate treatment

Background

KIR genes coding for natural killer cell immunoglobulin-like receptors, KIR, influence the effector and regulatory function of NK cells as well as some subpopulations of T lymphocytes (e.g. CD4+CD28-KIR+) depending on presence of ligands (particularly HLA-C molecules). KIR-KIR ligand interaction may lead to the development of autoimmune disorders, including rheumatoid arthritis (RA). However, their role in the response of RA patients to methotrexate therapy is not known.

Methods

KIR genes and KIR-ligand (HLA-C C1/C2 allomorphs) genotyping was performed using the PCR-SSP method in 312 RA patients (179 classified as good responders and 133 as poor responders using DAS28 criteria). Thus, we evaluated the association of KIR genes and HLA-C allomorphs with the response to methotrexate (MTX) treatment.

Results

We observed that patients possessing the full-length KIR2DS4 (KIR2DS4f) gene had a lower chance of responding in comparison to KIR2DS4f-negative cases. This phenomenon was observed both in erosive disease (ED) and rheumatoid factor (RF) positive and in ED- and RF-negative patients. Interestingly, the observed effect of the KIR2DS4f gene was strongest in individuals possessing medium values (20-33 mm/h) of the erythrocyte sedimentation rate (ESR). Patients with high ESR values had low probability and, in contrast, patients with low ESR had a high probability of MTX response, and the presence of KIR2DS4f did not affect their outcome. Additionally, we show that the KIR2DS4f effect did not depend on the presence of either C1 or C2 allomorphs.

Conclusion

Our results suggest that the response of RA patients with medium ESR values to MTX treatment may be dependent on the full-length KIR2DS4 gene.

Killer-cell immunoglobulin-like receptor expression on lymphocyte subsets in multiple sclerosis patients treated with interferon-β: evaluation as biomarkers for clinical response

BACKGROUND

Both the adaptative and the innate immune systems interplay in multiple sclerosis (MS) pathogeny. Killer-cell immunoglobulin-like receptors (KIRs) are key regulators of the immune response, with activating and inhibitory isoforms.

OBJECTIVE

In this study we analysed whether the expression of KIR isoforms is implicated in MS pathogenesis and in the therapeutic response to interferon (IFN)-β.

METHODS

Peripheral blood samples were collected from 78 IFN-β-treated MS patients and 46 healthy controls (HC). KIR expression was evaluated by flow cytometry on natural killer (NK) and T cells.

RESULTS

The expression of KIRs on NK cells and T lymphocytes did not differ between MS patients and HC. IFN-β therapy decreased the expression of KIR2DL1/2DS1 and increased that of KIR2DL2/3 on NK cells. This therapy also reduced KIR2DL1/2DS1, KIR2DL2/2DL3 and KIR3DL2 expression on CD8(+) T cells. The baseline evaluation of the percentage of circulating CD16(+) NK cells was predictive of the clinical response to IFN-β; however, response to this therapy did not appear related to KIR expression.

CONCLUSIONS

This study shows that expression of KIR isoforms on NK and T lymphocytes correlated in different ways with IFN-β therapy, suggesting that KIR dynamics may be associated with the pathways involved in the mechanisms of action of IFN-β.

High numbers of differentiated effector CD4 T cells are found in patients with cancer and correlate with clinical response after neoadjuvant therapy of breast cancer

CD4(+) T cells influence tumor immunity in complex ways that are not fully understood. In this study, we characterized a population of human differentiated effector CD4(+) T cells that is defined by low levels of the interleukin (IL)-2 and IL-7 receptors (CD25(-)CD127(-)). We found that this cell population expands in patients with various types of cancer, including breast cancer, to represent 2% to 20% of total CD4(+) blood T lymphocytes as compared with only 0.2% to 2% in healthy individuals. Notably, these CD25(-)CD127(-)CD4 T cells expressed effector markers such as CD244 and CD11b with low levels of CD27, contrasting with the memory phenotype dominating this population in healthy individuals. These cells did not cycle in patients, nor did they secrete IL-10 or IL-17, but instead displayed cytotoxic features. Moreover, they encompassed oligoclonal expansions paralleling an expansion of effector CD8(+) T cells that included tumor antigen-specific T cells. During neoadjuvant chemotherapy in patients with breast cancer, we found that the increase in CD25(-)CD127(-) CD4(+) T cells correlated with tumor regression. This observation suggested that CD4(+) T cells included tumor antigen-specific cells, which may be generated by or participate in tumor regressions during chemotherapy. In summary, our results lend support to the hypothesis that CD4(+) T cells are involved in human antitumor responses.

Standardization of whole blood immune phenotype monitoring for clinical trials: panels and methods from the ONE study

Background

Immune monitoring by flow cytometry is a fast and highly informative way of studying the effects of novel therapeutics aimed at reducing transplant rejection or treating autoimmune diseases. The ONE Study consortium has recently initiated a series of clinical trials aimed at using different cell therapies to promote tolerance to renal allografts. To compare the effectiveness of different cell therapies, the consortium developed a robust immune monitoring strategy, including procedures for whole blood (WB) leukocyte subset profiling by flow cytometry.

Methods

Six leukocyte profiling panels computing 7- to 9-surface marker antigens for monitoring the major leukocyte subsets as well as characteristics of T cell, B cell, and dendritic cell (DC) subsets were designed. The precision and variability of these panels were estimated. The assay was standardized within eight international laboratories using Flow-Set Pro beads for mean fluorescence intensity target definition and the flow cytometer setup procedure. Standardization was demonstrated by performing inter-site comparisons.

Results

Optimized methods for sample collection, storage, preparation, and analysis were established, including protocols for gating target subsets. WB specimen age testing demonstrated that staining must be performed within 4 hours of sample collection to keep variability low, meaning less than or equal to 10% for the majority of defined leukocyte subsets. Inter-site comparisons between all participating centers testing shipped normal WB revealed good precision, with a variability of 0.05% to 30% between sites. Intra-assay analyses revealed a variability of 0.05% to 20% for the majority of subpopulations. This was dependent on the frequency of the particular subset, with smaller subsets showing higher variability. The intra-assay variability performance defined limits of quantitation (LoQ) for subsets, which will be the basis for assessing statistically significant differences achieved by the different cell therapies.

Conclusions

Local performance and central analysis of the ONE Study flow cytometry panel yields acceptable variability in a standardized assay at multiple international sites. These panels and procedures with WB allow unmanipulated analysis of changes in absolute cell numbers of leukocyte subsets in single- or multicenter clinical trials. Accordingly, we propose the ONE Study panel may be adopted as a standardized method for monitoring patients in clinical trials enrolling transplant patients, particularly trials of novel tolerance promoting therapies, to facilitate fair and meaningful comparisons between trials.

Immunosenescence, aging, and systemic lupus erythematous

Senescence is a normal biological process that occurs in all organisms and involves a decline in cell functions. This process is caused by molecular regulatory machinery alterations, and it is closely related to telomere erosion in chromosomes. In the context of the immune system, this phenomenon is known as immunosenescence and refers to the immune function deregulation. Therefore, functions of several cells involved in the innate and adaptive immune responses are severely compromised with age progression (e.g., changes in lymphocyte subsets, decreased proliferative responses, chronic inflammatory states, etc.). These alterations make elderly individuals prone to not only infectious diseases but also to malignancy and autoimmunity. This review will explore the molecular aspects of processes related to cell aging, their importance in the context of the immune system, and their participation in elderly SLE patients.

Targeting the shift from M1 to M2 macrophages in experimental autoimmune encephalomyelitis mice treated with fasudil

We observed the therapeutic effect of Fasudil and explored its mechanisms in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Fasudil, a selective Rho kinase (ROCK) inhibitor, was injected intraperitoneally at 40 mg/kg/d in early and late stages of EAE induction. Fasudil ameliorated the clinical severity of EAE at different stages, and decreased the expression of ROCK-II in spleen, accompanied by an improvement in demyelination and inhibition of inflammatory cells. Fasudil mainly inhibited CD4⁺IL-17⁺ T cells in early treatment, but also elevated CD4⁺IL-10⁺ regulatory T cells and IL-10 production in late treatment. The treatment of Fasudil shifted inflammatory M1 to anti-inflammatory M2 macrophages in both early and late treatment, being shown by inhibiting CD16/32, iNOS, IL-12, TLR4 and CD40 and increasing CD206, Arg-1, IL-10 and CD14 in spleen. By using Western blot and immunohistochemistry, iNOS and Arg-1, as two most specific markers for M1 and M2, was inhibited or induced in splenic macrophages and spinal cords of EAE mice treated with Fasudil. In vitro experiments also indicate that Fasudil shifts M1 to M2 phenotype, which does not require the participation or auxiliary of other cells. The polarization of M2 macrophages was associated with the decrease of inflammatory cytokine IL-1β, TNF-α and MCP-1. These results demonstrate that Fasudil has therapeutic potential in EAE possibly through inducing the polarization of M2 macrophages and inhibiting inflammatory responses.