Effect of interferon-β1b on CXCR4-dependent chemotaxis in T cells from multiple sclerosis patients

Infiltration by monocytes of the central nervous system and its role in multiple sclerosis: reflections on therapeutic strategies

Mononuclear macrophage infiltration in the central nervous system is a prominent feature of neuroinflammation. Recent studies on the pathogenesis and progression of multiple sclerosis have highlighted the multiple roles of mononuclear macrophages in the neuroinflammatory process. Monocytes play a significant role in neuroinflammation, and managing neuroinflammation by manipulating peripheral monocytes stands out as an effective strategy for the treatment of multiple sclerosis, leading to improved patient outcomes. This review outlines the steps involved in the entry of myeloid monocytes into the central nervous system that are targets for effective intervention: the activation of bone marrow hematopoiesis, migration of monocytes in the blood, and penetration of the blood-brain barrier by monocytes. Finally, we summarize the different monocyte subpopulations and their effects on the central nervous system based on phenotypic differences. As activated microglia resemble monocyte-derived macrophages, it is important to accurately identify the role of monocyte-derived macrophages in disease. Depending on the roles played by monocyte-derived macrophages at different stages of the disease, several of these processes can be interrupted to limit neuroinflammation and improve patient prognosis. Here, we discuss possible strategies to target monocytes in neurological diseases, focusing on three key aspects of monocyte infiltration into the central nervous system, to provide new ideas for the treatment of neurodegenerative diseases.

Sex-dependent expression levels of VAV1 and P2X7 in PBMC of multiple sclerosis patients

Multiple sclerosis (MS) is an inflammatory autoimmune disorder of the central nervous system and the leading cause of progressive neurological disability in young adults. It decreases the patient's lifespan by about 10 years and affects women more than men. No medication entirely restricts or reverses neurological degradation. However, early diagnosis and treatment increase the possibility of a better outcome. To identify new MS biomarkers, we tested the expression of six potential markers (P2X4, P2X7, CXCR4, RGS1, RGS16 and VAV1) using qPCR in peripheral blood mononuclear cells (PBMC) of MS patients treated with interferon β (IFNβ), with glatiramer acetate (GA) or untreated. We showed that P2X7 and VAV1 are significantly induced in MS patients. In contrast, the expression of P2X4, CXCR4, RGS1 and RGS16 was not significantly modified by MS in PBMC. P2X7 and VAV1 are essentially induced in female patients, suggesting these markers are connected to sex-specific mechanisms. Strikingly, VAV1 expression is higher in healthy women than healthy men and IFNβ treatment of MS reduced VAV1 expression in female MS patients while it up-regulated VAV1 in male MS patients. Our data point to the differential, sex-dependent value of MS markers and treatment effects. Although rgs16 expression in PBMC was not a valid MS marker in patients, the strong upregulation of P2X4 and P2X7 induced in the spinal cord of WT mice by EAE was abrogated in rgs16KO mice suggesting that rgs16 is required for P2X4 and P2X7 induction by neurological diseases.

Strategy and application of manipulating DCs chemotaxis in disease treatment and vaccine design

As the most versatile antigen-presenting cells (APCs), dendritic cells (DCs) function as the cardinal commanders in orchestrating innate and adaptive immunity for either eliciting protective immune responses against canceration and microbial invasion or maintaining immune homeostasis/tolerance. In fact, in physiological or pathological conditions, the diversified migratory patterns and exquisite chemotaxis of DCs, prominently manipulate their biological activities in both secondary lymphoid organs (SLOs) as well as homeostatic/inflammatory peripheral tissues in vivo. Thus, the inherent mechanisms or regulation strategies to modulate the directional migration of DCs even could be regarded as the crucial cartographers of the immune system. Herein, we systemically reviewed the existing mechanistic understandings and regulation measures of trafficking both endogenous DC subtypes and reinfused DCs vaccines towards either SLOs or inflammatory foci (including neoplastic lesions, infections, acute/chronic tissue inflammations, autoimmune diseases and graft sites). Furthermore, we briefly introduced the DCs-participated prophylactic and therapeutic clinical application against disparate diseases, and also provided insights into the future clinical immunotherapies development as well as the vaccines design associated with modulating DCs mobilization modes.

Dimethyl fumarate promotes B cell-mediated anti-inflammatory cytokine profile in B and T cells, and inhibits immune cell migration in patients with MS

Dimethyl Fumarate (DMF), known for its mechanism of action targeting Nrf2 and related redox homeostasis, is an approved immunotherapy for patients with Multiple Sclerosis (PwMS) in the relapsing form. We assessed how DMF modulates immune cell functions, namely the cytokine profile of co-cultured B and T cells, and the chemokine-mediated migration of immune cells. Following DMF therapy, LTα⁺, TNFα⁺ and IFNγ⁺ B cells were reduced while TGFβ and IL10 expression elevated. B cells from DMF-treated patients increased TGFβ and LTα expression on T cells, while DMF directly reduced TNFα⁺ and IFNγ⁺ T cells. CXCL12/CXCL13-mediated migration of B cells, Monocytes, CD4 and CD8 T cells was reduced, with altered CXCR5 and CXCR4 expression. Induction of regulatory B and T cells and reduced migration of immune cells may be part of the beneficial mechanism of DMF in PwMS.

Modulating acute neuroinflammation in intracerebral hemorrhage: the potential promise of currently approved medications for multiple sclerosis

The secondary inflammatory injury following intracerebral hemorrhage (ICH) results in increased morbidity and mortality. White blood cells have been implicated as critical mediators of this inflammatory injury. Currently, no medications have been clinically proven to ameliorate or beneficially modulate inflammation, or to improve outcomes by any mechanism, following ICH. However, other neuroinflammatory conditions, such as multiple sclerosis, have approved pharmacologic therapies that modulate the inflammatory response and minimize the damage caused by inflammatory cells. Thus, there is substantial interest in existing therapies for neuroinflammation and their potential applicability to other acute neurological diseases such as ICH. In this review, we examined the mechanism of action of twelve currently approved medications for multiple sclerosis: alemtuzumab, daclizumab, dimethyl fumarate, fingolimod, glatiramer acetate, interferon beta-1a, interferon beta-1b, mitoxantrone, natalizumab, ocrelizumab, rituximab, teriflunomide. We analyzed the existing literature pertaining to the effects of these medications on various leukocytes and also with emphasis on mechanisms of action during the acute period following initiation of therapy. As a result, we provide a valuable summary of the current body of knowledge regarding these therapies and evidence that supports or refutes their likely promise for treating neuroinflammation following ICH.

Lymphocyte integrin expression differences between SIRS and sepsis patients

BACKGROUND

Systemic Inflammatory Response Syndrome (SIRS) and sepsis remain leading causes of death. Despite many similarities, the two entities are very distinct clinically and immunologically. T-Lymphocytes play a key pivotal role in the pathogenesis and ultimately outcome following both SIRS and sepsis. Integrins are essential in the trafficking and migration of lymphocytes. They also serve vital roles in efficient wound healing and clearance of infections. Here, we investigate whether integrin expression, specifically β1 (CD29) and β2 (CD18), are disrupted in SIRS and sepsis, and assess differences in integrin expression between these two critically ill clinical categories.

METHODS

T-Lymphocytes were isolated from whole blood collected from ICU patients exhibiting SIRS or sepsis. Samples were analyzed for CD18 (β2) and CD29 (β1) on CD3⁺ T cells through flow cytometry. Septic patients were stratified into either exclusively abdominal or non-abdominal sources of sepsis.

RESULTS

CD18 was almost ubiquitously expressed on CD3⁺ T cells irrespective of clinical condition. However, CD29 (β1 integrin) was lowest in SIRS patients (20.4% of CD3⁺ T cells) when compared with either septic patients (35.5%) or healthy volunteers (54.1%). Furthermore, there was evidence of compartmentalization in septic patients, where abdominal sources had a greater percentage of CD3⁺CD29⁺ T cells (41.7%) when compared with those with non-abdominal sources (29.5%).

CONCLUSION

Distinct differences in T-cell integrin expression exists between patients in SIRS versus sepsis, as well as relative to the source of sepsis. Further work is needed to understand cause and effect relative to the progression from SIRS into sepsis.

In vitro evaluation of physiologically relevant concentrations of teriflunomide on activation and proliferation of primary rodent microglia

Background

Teriflunomide, an inhibitor of dihydroorotate dehydrogenase, is thought to ameliorate multiple sclerosis by reducing activation-induced proliferation of lymphocytes, which is highly dependent on de novo pyrimidine synthesis. Nevertheless, its immunomodulatory effects on resident glial cells in the central nervous system are only poorly understood.

Methods

In this study, we employed physiologically relevant concentrations of teriflunomide and investigated its effects on survival, proliferation, activation, and function of primary rat microglia in vitro.

Results

We demonstrate that teriflunomide had no cytotoxic effect on microglia and had only a minor impact on microglial activation. In a concentration- and time-dependent manner, teriflunomide significantly downregulated surface expression of the co-stimulatory molecule CD86. Furthermore, in the highest concentration applied (5 μM), it slightly increased the expression of interleukin-10 in microglia in response to lipopolysaccharide. Treatment with low concentrations of teriflunomide (0.25–1 μM) did not have any impact on the activation or proliferation of microglia. At 5 μM concentration of teriflunomide, we observed a reduction of approximately 30 % in proliferation of microglia in mixed glial cell cultures.

Conclusions

Taken together, our in vitro findings suggest that at higher concentrations, teriflunomide potentially exerts its effects by reducing microglial proliferation and not by modulating the M1-/M2-like cell differentiation of primary rat microglia. Thus, teriflunomide has no major impact on the plasticity of microglia; however, the anti-proliferative and minimal anti-inflammatory effects might be clinically relevant for immune modulation in the treatment of neuroinflammatory CNS diseases such as multiple sclerosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-016-0715-3) contains supplementary material, which is available to authorized users.

Anti-metastatic functions of type 1 interferons: Foundation for the adjuvant therapy of cancer

The anti-tumorigenic effects that type 1 interferons (IFN1) elicited in the in vitro studies prompted consideration of IFN1 as a potent candidate for clinical treatment. Though not all patients responded to IFN1, clinical trials have shown that patients with high risk melanoma, a highly refractory solid malignancy, benefit greatly from intermediate IFN1 treatment in regards to relapse-free and distant-metastasis-free survival. The mechanisms by which IFN1 treatment at early stages of disease suppress tumor recurrence or metastatic incidence are not fully understood. Intracellular IFN1 signaling is known to affect cell differentiation, proliferation, and apoptosis. Moreover, recent studies have revealed specific IFN1-regulated genes that may contribute to IFN1-mediated suppression of cancer progression and metastasis. In concert, expression of these different IFN1 stimulated genes may impede numerous mechanisms that mediate metastatic process. Though, IFN1 treatment is still utilized as part of standard care for metastatic melanoma (alone or in combination with other therapies), cancers find the ways to develop insensitivity to IFN1 treatment allowing for unconstrained disease progression. To determine how and when IFN1 treatment would be most efficacious during disease progression, we must understand how IFN1 signaling affects different metastasis steps. Here, we specifically focus on the anti-metastatic role of endogenous IFN1 and parameters that may help to use pharmaceutical IFN1 in the adjuvant treatment to prevent cancer recurrence and metastatic disease.

R4 Regulator of G Protein Signaling (RGS) Proteins in Inflammation and Immunity

G protein-coupled receptors (GPCRs) have important functions in both innate and adaptive immunity, with the capacity to bridge interactions between the two arms of the host responses to pathogens through direct recognition of secreted microbial products or the by-products of host cells damaged by pathogen exposure. In the mid-1990s, a large group of intracellular proteins was discovered, the regulator of G protein signaling (RGS) family, whose main, but not exclusive, function appears to be to constrain the intensity and duration of GPCR signaling. The R4/B subfamily--the focus of this review--includes RGS1-5, 8, 13, 16, 18, and 21, which are the smallest RGS proteins in size, with the exception of RGS3. Prominent roles in the trafficking of B and T lymphocytes and macrophages have been described for RGS1, RGS13, and RGS16, while RGS18 appears to control platelet and osteoclast functions. Additional G protein independent functions of RGS13 have been uncovered in gene expression in B lymphocytes and mast cell-mediated allergic reactions. In this review, we discuss potential physiological roles of this RGS protein subfamily, primarily in leukocytes having central roles in immune and inflammatory responses. We also discuss approaches to target RGS proteins therapeutically, which represents a virtually untapped strategy to combat exaggerated immune responses leading to inflammation.