CCL5 and CCR5 genotypes modify clinical, radiological and pathological features of multiple sclerosis

Engineered immunological niche directs therapeutic development in models of progressive multiple sclerosis

Primary progressive multiple sclerosis (MS) is a demyelinating autoimmune disease with only a single class of FDA-approved treatment, B cell depletion. Novel treatments could emerge from a deeper understanding of the interplay between multiple cell types within diseased tissue throughout progression. We initially describe an engineered biomaterial-based immunological niche (IN) as a surrogate for diseased tissue to investigate immune cell function and phenotype dynamics throughout a chronic progressive mouse model of MS. Using these niches, we identify an array of dysregulated CC chemokine signaling as potential targets. We then develop antigen-loaded nanoparticles that reduce CC chemokine signaling, while delivering antigen. These nanoparticles serve as an antigen-specific treatment, and a single injection reduces disease burden, even if administered after symptomatic disease onset. This report demonstrates proof of principle of a biomaterial scaffold as a diseased tissue surrogate that can monitor immune function, identify potential drug targets, and guide the development of a therapeutic.

Immunologic analysis of CSF in patients with de novo diagnosed RRMS. The role of chemokines in the early phase of the disease

OBJECTIVES

Multiple sclerosis (MS) is a chronic CNS autoimmune disease characterized by demyelination and neurodegeneration. Chemokines regulate leukocyte migration and inflammation in MS. In the present study, we evaluated selected chemokine levels in the cerebrospinal fluid of patients with multiple sclerosis diagnosed de novo compared to healthy controls.

METHODS

We measured EOTAXIN, IP-10, MCP-1, MIP-1a, MIP-1b and RANTES in the cerebrospinal fluid of 118 patients with de novo RRMS and 112 controls, analyzing correlations with time from symptom onset to diagnosis and changes in MRI.

RESULTS

Higher levels of EOTAXIN, IP-10, MIP-1B and RANTES, and lower MCP-1 were observed in MS patients compared to controls. MIP-1A did not show statistical significance. EOTAXIN and IP-10 concentrations increased with time. RANTES concentration correlated positively with T2 changes in MRI of the cervical spine, and EOTAXIN concentration correlated negatively with gadolinium (Gd+) changes in the cervical spine. There was no correlation with changes in the thoracic spine or brain.

CONCLUSIONS

Chemokines play a significant role in the early phase of MS by influencing inflammatory activity. They may represent potential therapeutic targets for the treatment of this disease.

Low sulfated heparan sulfate mimetic differentially affects repair in immune-mediated and toxin-induced experimental models of demyelination

There is an urgent need for therapies that target the multicellular pathology of central nervous system (CNS) disease. Modified, nonanticoagulant heparins mimic the heparan sulfate glycan family and are known regulators of multiple cellular processes. In vitro studies have demonstrated that low sulfated modified heparin mimetics (LS-mHeps) drive repair after CNS demyelination. Herein, we test LS-mHep7 (an in vitro lead compound) in experimental autoimmune encephalomyelitis (EAE) and cuprizone-induced demyelination. In EAE, LS-mHep7 treatment resulted in faster recovery and rapidly reduced inflammation which was accompanied by restoration of animal weight. LS-mHep7 treatment had no effect on remyelination or on OLIG2 positive oligodendrocyte numbers within the corpus callosum in the cuprizone model. Further in vitro investigation confirmed that LS-mHep7 likely mediates its pro-repair effect in the EAE model by sequestering inflammatory cytokines, such as CCL5 which are upregulated during immune-mediated inflammatory attacks. These data support the future clinical translation of this next generation modified heparin as a treatment for CNS diseases with active immune system involvement.

The Relationship of CCL5 and CCR1 Variants with Response Rate and Survival Taking into Account Thalidomide/Bortezomib Treatment in Patients with Multiple Myeloma

(1) Background: Chemokines and chemokine receptors play an important role in tumor development. The aim of this study was to check the significance of CCL5 and CCR1 variants with response rate, survival, and the level of regulated on activation, normal T cells expressed and secreted (RANTES/CCL5) in multiple myeloma (MM) patients; (2) Methods: Genomic DNA from 101 newly diagnosed MM patients and 100 healthy blood donors were analyzed by Real-time PCR method (for CCL5 and CCR1 genotyping). In a subgroup of 70 MM patients, serum samples were collected to determine the level of RANTES; (3) Results: multivariate Cox regression showed increased risk of disease relapse or progression (HR = 4.77; p = 0.01) in MM patients with CG + CC genotypes of CCL5 rs2280788. In contrast, CT + TT genotypes of CCL5 rs2107538 were associated withdecreased risk of death (HR = 0.18; p = 0.028) and disease relapse or progression (HR = 0.26; p = 0.01). In MM patients with major genotypes of rs2280789, rs2280788, and rs2107538, higher survival rates were observed in response to treatment with thalidomide and bortezomib. Statistically significant lower RANTES levels were seen in minor genotypes and heterozygotes of CCL5 and CCR1 variants; (4) Conclusions: Major genotypes of CCL5 variants may be independent positive prognostic factors in MM.

Serological biomarkers in autoimmune GFAP astrocytopathy

Autoimmune glial fibrillary acidic protein astrocytopathy (GFAP-A) is a newly defined meningoencephalomyelitis. The pathogenesis of GFAP-A is not well understood. The present study measured the expression levels of 200 serological cytokines in GFAP-A patients, NMOSD patients and healthy controls (HCs). The correlations between serum cytokine levels and clinical information in GFAP-A patients were analyzed. A total of 147 serological proteins were differentially expressed in GFAP-A patients compared to HCs, and 33 of these proteins were not observed in NMOSD patients. Serum levels of EG-VEGF negatively correlated with GFAP antibody titers, MIP-3 alpha positively correlated with clinical severity in GFAP-A patients, and LIGHT positively correlated with WBC counts and protein levels in the CSF of GFAP-A patients. These results suggest that GFAP and AQP4 astrocytopathy share some common pathology related to TNF signaling. Serum MIP 3 alpha may be a biomarker to assess clinical severity and a potential target for therapy of autoimmune GFAP astrocytopathy.

MS-driven metabolic alterations are recapitulated in iPSC-derived astrocytes

Objective

Astrocytes play a significant role in the pathology of multiple sclerosis (MS). Nevertheless, for ethical reasons, most studies in these cells were performed using the Experimental Autoimmune Encephalomyelitis model. As there are significant differences between human and mouse cells, we aimed here to better characterize astrocytes from patients with MS (PwMS), focusing mainly on mitochondrial function and cell metabolism.

Methods

We obtained and characterized induced pluripotent stem cell (iPSC)‐derived astrocytes from three PwMS and three unaffected controls, and performed electron microscopy, flow cytometry, cytokine and glutamate measurements, gene expression, in situ respiration, and metabolomics. We validated our findings using a single‐nuclei RNA sequencing dataset.

Results

We detected several differences in MS astrocytes including: (i) enrichment of genes associated with neurodegeneration, (ii) increased mitochondrial fission, (iii) increased production of superoxide and MS‐related proinflammatory chemokines, (iv) impaired uptake and enhanced release of glutamate, (v) increased electron transport capacity and proton leak, in line with the increased oxidative stress, and (vi) a distinct metabolic profile, with a deficiency in amino acid catabolism and increased sphingolipid metabolism, which have already been linked to MS.

Interpretation

Here we describe the metabolic profile of iPSC‐derived astrocytes from PwMS and validate this model as a very powerful tool to study disease mechanisms and to perform non‐invasive drug targeting assays in vitro. Our findings recapitulate several disease features described in patients and provide new mechanistic insights into the metabolic rewiring of astrocytes in MS, which could be targeted in future therapeutic studies. ANN NEUROL 2022;91:652–669

CCR5Δ32 in Brazil: Impacts of a European Genetic Variant on a Highly Admixed Population

The genetic background of Brazilians encompasses Amerindian, African, and European components as a result of the colonization of an already Amerindian inhabited region by Europeans, associated to a massive influx of Africans. Other migratory flows introduced into the Brazilian population genetic components from Asia and the Middle East. Currently, Brazil has a highly admixed population and, therefore, the study of genetic factors in the context of health or disease in Brazil is a challenging and remarkably interesting subject. This phenomenon is exemplified by the genetic variant CCR5Δ32, a 32 base-pair deletion in the CCR5 gene. CCR5Δ32 originated in Europe, but the time of origin as well as the selective pressures that allowed the maintenance of this variant and the establishment of its current frequencies in the different human populations is still a field of debates. Due to its origin, the CCR5Δ32 allele frequency is high in European-derived populations (~10%) and low in Asian and African native human populations. In Brazil, the CCR5Δ32 allele frequency is intermediate (4-6%) and varies on the Brazilian States, depending on the migratory history of each region. CCR5 is a protein that regulates the activity of several immune cells, also acting as the main HIV-1 co-receptor. The CCR5 expression is influenced by CCR5Δ32 genotypes. No CCR5 expression is observed in CCR5Δ32 homozygous individuals. Thus, the CCR5Δ32 has particular effects on different diseases. At the population level, the effect that CCR5Δ32 has on European populations may be different than that observed in highly admixed populations. Besides less evident due to its low frequency in admixed groups, the effect of the CCR5Δ32 variant may be affected by other genetic traits. Understanding the effects of CCR5Δ32 on Brazilians is essential to predict the potential use of pharmacological CCR5 modulators in Brazil. Therefore, this study reviews the impacts of the CCR5Δ32 on the Brazilian population, considering infectious diseases, inflammatory conditions, and cancer. Finally, this article provides a general discussion concerning the impacts of a European-derived variant, the CCR5Δ32, on a highly admixed population.

BMS-813160: A Potent CCR2 and CCR5 Dual Antagonist Selected as a Clinical Candidate

BMS-813160 (compound 3) was identified as a potent and selective CCR2/5 dual antagonist. Compound 3 displayed good permeability at pH = 7.4 in PAMPA experiments and demonstrated excellent human liver microsome stability. Pharmacokinetic studies established that 3 had excellent oral bioavailability and exhibited low clearance in dog and cyno. Compound 3 was also studied in the mouse thioglycollate-induced peritonitis model, which confirmed its ability to inhibit the migration of inflammatory monocytes and macrophages. As a result of this profile, compound 3 was selected as a clinical candidate.

RANTES/CCL5 Signaling from Jawbone Cavitations to Epistemology of Multiple Sclerosis - Research and Case Studies

BACKGROUND

The role played by signaling pathways in the cell-cell communication associated with multiple sclerosis (MS) progression has become a critical area in research. Chemokine RANTES (regulated upon activation, normal T-cell expressed and secreted), also named chemokine C-C motif ligand 5 (CCL5; R/C), is a protein that has been investigated in neuroinflammatory research due to its link to MS development.

OBJECTIVE

Research on bone marrow defects in the jawbone (BMDJ), which morphologically presents as fatty-degenerative osteonecrosis of the jawbone (FDOJ), presents overexpression of R/C signaling in affected areas. Here, we try to elucidate the potential link between jawbone-derived R/C and MS.

METHODS

Seventeen BMDJ/FDOJ samples extracted from 17 MS patients, as well as samples from 19 healthy controls, were analyzed for R/C expression using bead-based Luminex® analysis. The serum R/C levels from 10 MS patients were examined. Further, bone density, histology, and R/C expression were analyzed in two clinical case studies.

RESULTS

High R/C overexpression was found in all BMDJ/FDOJ samples obtained from the MS group. Serum R/C levels were also upregulated in the MS group. R/C serum levels in the MS cohort were higher than in the healthy controls. In contrast, the histology of BMDJ/FDOJ samples showed no inflammatory cells.

DISCUSSION

R/C-induced "silent inflammation" in MS is widely discussed in the scientific literature, along with R/C triggering of inflammation in the central nervous system, which might be key in the development of MS.

CONCLUSION

The authors suspect that BMDJ/FDOJ may serve as a trigger of MS progression via R/C overexpression. As such, the dental and medical communities should be made aware of BMDJ/FDOJ in cases of MS.

A Single Nucleotide ADA Genetic Variant Is Associated to Central Inflammation and Clinical Presentation in MS: Implications for Cladribine Treatment

In multiple sclerosis (MS), activated T and B lymphocytes and microglial cells release various proinflammatory cytokines, promoting neuroinflammation and negatively affecting the course of the disease. The immune response homeostasis is crucially regulated by the activity of the enzyme adenosine deaminase (ADA), as evidenced in patients with genetic ADA deficiency and in those treated with cladribine tablets. We investigated in a group of patients with MS the associations of a single nucleotide polymorphism (SNP) of ADA gene with disease characteristics and cerebrospinal fluid (CSF) inflammation. The SNP rs244072 of the ADA gene was determined in 561 patients with MS. Disease characteristics were assessed at the time of diagnosis; furthermore, in 258 patients, proinflammatory and anti-inflammatory molecules were measured in the CSF. We found a significant association between rs244072 and both clinical characteristics and central inflammation. In C-carriers, significantly enhanced disability and increased CSF levels of TNF, IL-5 and RANTES was observed. In addition, lower CSF levels of the anti-inflammatory cytokine IL-10 were found. Finally, the presence of the C allele was associated with a tendency of increased lymphocyte count. In MS patients, ADA SNP rs244072 is associated with CSF inflammation and disability. The selective targeting of the ADA pathway through cladribine tablet therapy could be effective in MS by acting on a pathogenically relevant biological mechanism.

Metformin as a Potential Agent in the Treatment of Multiple Sclerosis

Metformin, a synthetic derivative of guanidine, is commonly used as an oral antidiabetic agent and is considered a multi-vector application agent in the treatment of other inflammatory diseases. Recent studies have confirmed the beneficial effect of metformin on immune cells, with special emphasis on immunological mechanisms. Multiple Sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) characterized by various clinical courses. Although the pathophysiology of MS remains unknown, it is most likely a combination of disturbances of the immune system and biochemical pathways with a disruption of blood-brain barrier (BBB), and it is strictly related to injury of intracerebral blood vessels. Metformin has properties which are greatly desirable for MS therapy, including antioxidant, anti-inflammatory or antiplatelet functions. The latest reports relating to the cardiovascular disease confirm an increased risk of ischemic events in MS patients, which are directly associated with a coagulation cascade and an elevated pro-thrombotic platelet function. Hence, this review examines the potential favourable effects of metformin in the course of MS, its role in preventing inflammation and endothelial dysfunction, as well as its potential antiplatelet role.

Metabolomics as an Approach to Characterise the Contrasting Roles of CCR5 in the Presence and Absence of Disease

Chemokine receptors such as C-C chemokine receptor 5 (CCR5) are activated through interaction with their ligands and are well known for their role in chemotaxis and signal transduction. While serving these roles, cellular responses are effected, hence the immune function of these molecules is established. Given the role of CCR5 in immune function and that the immune and metabolic systems are interlinked, subsequent immune-directed changes should be measurable at a metabolic level. Numerous investigations have reported on metabolic changes associated with CCR5 status in the presence of disease, so as to understand whether specific CCR5 genotypes, frequency and/or levels offer protection to the host or not. However, these metabolic changes were recorded using older conventional techniques. Depending on certain factors such as the disease model, the geography of the samples and/or the ethnic group under study, the role of CCR5 in disease differs. In addition, little is known about CCR5's role in the absence of an enhanced inflammatory state, such as when infection persists. Metabolomics is defined as the study of metabolites and informs on metabolic changes within living organisms as induced by various stimuli, such as the interaction of CCR5 with its ligand. Since metabolomics reflects the underlying biochemical activity and state of cells/tissues, this review proposes it as a tool to clarify the contrasting roles of CCR5.

Post-mortem multiple sclerosis lesion pathology is influenced by single nucleotide polymorphisms

Over the last few decades, several common single nucleotide polymorphisms (SNPs) have been identified that correlate with clinical outcome in multiple sclerosis (MS), but the pathogenic mechanisms underlying the clinical effects of these SNPs are unknown. This is in part because of the difficulty in the functional translation of genotype into disease-relevant mechanisms. Building on our recent work showing the association of clinical disease course with post-mortem MS lesion characteristics, we hypothesized that SNPs that correlate with clinical disease course would also correlate with specific MS lesion characteristics in autopsy tissue. To test this hypothesis, 179 MS brain donors from the Netherlands Brain Bank MS autopsy cohort were genotyped for 102 SNPs, selected based on their reported associations with clinical outcome or their associations with genes that show differential gene expression in MS lesions. Three SNPs linked to MS clinical severity showed a significant association between the genotype and either the proportion of active lesions (rs2234978/FAS and rs11957313/KCNIP1) or the proportion of mixed active/inactive lesions (rs8056098/CLEC16A). Three SNPs linked to MS pathology-associated genes showed a significant association with either proportion of active lesions (rs3130253/MOG), incidence of cortical gray matter lesions (rs1064395/NCAN) or the proportion of remyelinated lesions (rs5742909/CTLA4). In addition, rs2234978/FAS T-allele carriers showed increased FAS gene expression levels in perivascular T cells and perilesional oligodendrocytes, cell types that have been implicated in MS lesion formation. Thus, by combining pathological characterization of MS brain autopsy tissue with genetics, we now start to translate genotypes linked to clinical outcomes in MS into mechanisms involved in MS lesion pathogenesis.

Impact of fingolimod on CD4+ T cell subset and cytokine profile of relapsing remitting multiple sclerosis patients

Fingolimod inhibits the egress of lymphocytes from lymphatic tissues and also directly affects their functions by modulation of the sphingosine-1-phosphate receptor 1 (S1P1). Our aim was to evaluate the impact of fingolimod on diverse CD4+ T cell subsets, and cytokines. Sixty-six relapsing remitting multiple sclerosis (RRMS) patients were treated with oral fingolimod (0.5 mg) for 6 months, and blood samples were collected at baseline, 3 months, and 6 months. Serum levels of seven cytokines and five chemokines were measured by multiplex immunoassay, and frequencies of peripheral blood mononuclear cell subsets were assessed by flow cytometry, and compared with those of 60 healthy controls. CCL2 (p = 0.039), and CCL5 (p = 0.001) levels were significantly higher in fingolimod-treated patients than healthy controls, whereas end-of-study serum levels of IL-6, IL-8, IL-17A, IL-22, IL-23, TNF-α, CXCL10, and CXCL13 were comparable to the baseline levels. Six months of fingolimod treatment reduced CD3+ T cell (mean ± standard deviation, 72.9% ± 5.5 vs. 60.1% ± 11.1, p < 0.001), CD4+ T cell (62.2% ± 8.5 vs. 24.6% ± 12.9, p < 0.001), CD4+CD25hi regulatory T cell (Treg) (3.4% ± 1.3 vs. 2.0% ± 1.4, p < 0.01), and CD19+ B cell (13.2% ± 5.8 vs. 5.3% ± 2.7, p < 0.001) frequencies, while CD8+ T cells (31.8% ± 7.8 vs. 57.8% ± 13.2, p < 0.001) were increased, and NK and NKT cells remained unchanged. The proportions of intracytoplasmic IL-4, IL-10, IFN-γ, and TNF-α-producing T cells were increased, whereas IL-17-producing cells remained relatively constant as measured by flow cytometry. Fingolimod appears to primarily diminish lymphocyte subsets involved in antigen presentation (CD19+ B and CD4+ T cells) rather than immune cells (CD8+ T, NK, and NKT cells) in charge of host defense against pathogens. In contrast, a relative increase is observed in pro- and anti-inflammatory cytokine-producing T helper subsets (IFN-γ, TNF-α, IL-4, and IL-10-producing CD4+ T cells), suggesting that effector T cells are suppressed to a lesser degree by S1P1 modulation.

Increased CCL18 plasma levels are associated with neurodegenerative MRI outcomes in multiple sclerosis patients

BACKGROUND

Chemokine ligands and co-stimulatory factors are involved in macrophage activation and differentiation processes that could contribute to multiple sclerosis (MS) pathogenesis.

OBJECTIVE

To investigate associations of C-C motif Ligand 18 (CCL18), C-C motif ligand 5 (CCL5) and soluble Cluster of Differentiation 86 (sCD86) with clinical and MRI measures in MS patients.

METHODS

Plasma levels of CCL18, CCL5 and sCD86 were evaluated in 138 MS patients (85 relapsing-remitting, RR-MS; 53 progressive, P-MS), and in 42 age- and sex-matched healthy individuals (HI). All subjects underwent standardized 3T MRI and clinical examinations. Multiple regression analysis of MRI outcomes as dependent variables was performed with age, gender, having P-MS, and plasma proteins as predictor variables.

RESULTS

Higher CCL18 plasma levels were found in P-MS (median = 51.5, IQR = 41.0-63.6 ng/mL) compared to RR-MS (median = 43.0, IQR = 29.1-55.0 ng/mL, p = 0.014) and to HI (median = 41.3, IQR = 30.9-54.1 ng/mL, p = 0.009). Disease-modifying treatments altered CCL5 (p = 0.036) and sCD86 (p < 0.001) levels. Higher CCL18 levels were associated with increased lateral ventricular volume (p = 0.006) and T2 lesion volume (LV) (p = 0.034), and decreased grey matter (p = 0.006), thalamic (p = 0.007) and cortical (p = 0.01) volumes.

CONCLUSIONS

Our results provide evidence that higher CCL18 plasma levels are associated with more severe inflammatory and neurodegenerative brain MRI outcomes in MS.

CCR5Δ32 - A piece of protection in the inflammatory puzzle of multiple sclerosis susceptibility

BACKGROUND

Leucocyte infiltration and activation in the central nervous system (CNS) is an important step in the pathogenesis of multiple sclerosis (MS). The Chemokine receptor 5 (CCR5) is implicated in immune cell migration and cytokine release in the CNS, and it was demonstrated to strongly contribute to CNS inflammation and damage in several models of sterile and pathogen-mediated CNS diseases. Although the inhibition of CCR5 results in a beneficial effect in experimental models of MS, conflicting results have been found about the loss-of-function variant CCR5Δ32 (rs333) in MS patients. The aim of this study was to evaluate the association of CCR5Δ32 and MS in a Brazilian case/control cohort.

PATIENTS AND METHODS

261 MS patients and 435 healthy controls were genotyped for CCR5Δ32. Allelic and genotypic frequencies were compared between patients and controls (case/control analysis), and among patients classified according to the MS clinical form (relapsing remitting versus progressive) and severity (EDSS, MSSS and progression index).

RESULTS AND DISCUSSION

The CCR5Δ32 variant frequency was statistically higher in controls as compared to patients presenting European-derived ethnic background. The variant was more frequent in progressive MS as compared to RR-MS patients, and, although not statistically significant, a higher frequency of the truncated allele was observed among patients with less severe forms of MS. These findings emphasize the potential involvement of CCR5 signaling in CNS inflammation and damage in MS.

CONCLUSION

The CCR5Δ32 deletion is a protective factor against the development and progression of MS in European-derived Brazilian patients.

The Expanding Therapeutic Perspective of CCR5 Blockade

CCR5 and its interaction with chemokine ligands have been crucial for understanding and tackling HIV-1 entry into target cells. However, over time, CCR5 has witnessed an impressive transition from being considered rather unimportant in physiology and pathology to becoming central in a growing number of pathophysiological conditions. It now turns out that the massive efforts devoted to combat HIV-1 entry by interfering with CCR5, and the subsequent production of chemokine ligand variants, small chemical compounds, and other molecular entities and strategies, may set the therapeutic standards for a wealth of different pathologies. Expressed on various cell types, CCR5 plays a vital role in the inflammatory response by directing cells to sites of inflammation. Aside HIV-1, CCR5 has been implicated in other infectious diseases and non-infectious diseases such as cancer, atherosclerosis, and inflammatory bowel disease. Individuals carrying the CCR5Δ32 mutation live a normal life and are warranted a natural barrier to HIV-1 infection. Therefore, CCR5 antagonism and gene-edited knockout of the receptor gained growing interest for the therapeutic role that CCR5 blockade may play in the attenuation of the severity or progression of numerous diseases.

CCL5-Glutamate Cross-Talk in Astrocyte-Neuron Communication in Multiple Sclerosis

The immune system (IS) and the central nervous system (CNS) are functionally coupled, and a large number of endogenous molecules (i.e., the chemokines for the IS and the classic neurotransmitters for the CNS) are shared in common between the two systems. These interactions are key elements for the elucidation of the pathogenesis of central inflammatory diseases. In recent years, evidence has been provided supporting the role of chemokines as modulators of central neurotransmission. It is the case of the chemokines CCL2 and CXCL12 that control pre- and/or post-synaptically the chemical transmission. This article aims to review the functional cross-talk linking another endogenous pro-inflammatory factor released by glial cells, i.e., the chemokine Regulated upon Activation Normal T-cell Expressed and Secreted (CCL5) and the principal neurotransmitter in CNS (i.e., glutamate) in physiological and pathological conditions. In particular, the review discusses preclinical data concerning the role of CCL5 as a modulator of central glutamatergic transmission in healthy and demyelinating disorders. The CCL5-mediated control of glutamate release at chemical synapses could be relevant either to the onset of psychiatric symptoms that often accompany the development of multiple sclerosis (MS), but also it might indirectly give a rationale for the progression of inflammation and demyelination. The impact of disease-modifying therapies for the cure of MS on the endogenous availability of CCL5 in CNS will be also summarized. We apologize in advance for omission in our coverage of the existing literature.

Elevated Levels of Proinflammatory Cytokines in Cerebrospinal Fluid of Multiple Sclerosis Patients

Multiple sclerosis (MS) is an autoimmune neurodegenerative disease characterized by chronic brain inflammation. Leukocyte infiltration of brain tissue causes inflammation, demyelination, and the subsequent formation of sclerotic plaques, which are a hallmark of MS. Activation of proinflammatory cytokines is essential for regulation of lymphocyte migration across the blood–brain barrier. We demonstrate increased levels of many cytokines, including IL-2RA, CCL5, CCL11, MIF, CXCL1, CXCL10, IFNγ, SCF, and TRAIL, were upregulated in cerebrospinal fluid (CSF), whereas IL-17, CCL2, CCL3, CCL4, and IL-12(p40) were activated in MS serum. Interaction analysis of cytokines in CSF demonstrated a connection between IFNγ and CCL5 as well as MIF. Many cells can contribute to production of these cytokines including CD8 and Th1 lymphocytes and astrocytes. Therefore, we suggest that IFNγ released by Th1 lymphocytes can activate astrocytes, which then produce chemoattractants, including CCL5 and MIF. These chemokines promote an inflammatory milieu and interact with multiple chemokines including CCL27 and CXCL1. Of special note, upregulation of CCL27 was found in CSF of MS cases. This observation is the first to demonstrate CCL27 as a potential contributor of brain pathology in MS. Our data suggest that CCL27 may be involved in activation and migration of autoreactive encephalitogenic immune effectors in the brain. Further, our data support the role of Th1 lymphocytes in the pathogenesis of brain inflammation in MS, with several cytokines playing a central role.

An MRI-defined measure of cerebral lesion severity to assess therapeutic effects in multiple sclerosis

Assess the sensitivity of the Magnetic Resonance Disease Severity Scale (MRDSS), based on cerebral lesions and atrophy, for treatment monitoring of glatiramer acetate (GA) in relapsing-remitting multiple sclerosis (MS). This retrospective non-randomized pilot study included patients who started daily GA [n = 23, age (median, range) 41 (26.2, 53.1) years, Expanded Disability Status Scale (EDSS) score 1.0 (0, 3.5)], or received no disease-modifying therapy (noDMT) [n = 21, age 44.8 (28.2, 55.4), EDSS 0 (0, 2.5)] for 2 years. MRDSS was the sum of z-scores (normalized to a reference sample) of T2 hyperintense lesion volume (T2LV), the ratio of T1 hypointense LV to T2LV (T1/T2), and brain parenchymal fraction (BPF) multiplied by negative 1. The two groups were compared by Wilcoxon rank sum tests; within group change was assessed by Wilcoxon signed rank tests. Glatiramer acetate subjects had less progression than noDMT on T1/T2 [(median z-score change (range), 0 (−1.07, 1.20) vs. 0.41 (−0.30, 2.51), p = 0.003)] and MRDSS [0.01 (−1.33, 1.28) vs. 0.46 (−1.57, 2.46), p = 0.01]; however, not on BPF [0.12 (−0.18, 0.58) vs. 0.10 (−1.47,0.50), p = 0.59] and T2LV [−0.03 (−0.90, 0.57) vs. 0.01 (−1.69, 0.34), p = 0.40]. While GA subjects worsened only on BPF [0.12 (−0.18, 0.58), p = 0.001], noDMT worsened on BPF [0.10 (−1.47, 0.50), p = 0.002], T1/T2 [0.41 (−0.30, 2.51), p = 0.0002], and MRDSS [0.46 (−1.57, 2.46), p = 0.0006]. These preliminary findings show the potential of two new cerebral MRI metrics to track MS therapeutic response. The T1/T2, an index of the destructive potential of lesions, may provide particular sensitivity to treatment effects.

RANTES correlates with inflammatory activity and synaptic excitability in multiple sclerosis

BACKGROUND

Alterations of synaptic transmission induced by inflammatory activity have been linked to the pathogenic mechanisms of multiple sclerosis (MS). Regulated upon activation, normal T-cell expressed, and secreted (RANTES) is a pro-inflammatory chemokine involved in MS pathophysiology, potentially able to regulate glutamate release and plasticity in MS brains, with relevant consequences on the clinical manifestations of the disease.

OBJECTIVE

To assess the role of RANTES in the regulation of cortical excitability.

METHODS

We explored the association of RANTES levels in the cerebrospinal fluid (CSF) of newly diagnosed MS patients with magnetic resonance imaging (MRI) and laboratory measures of inflammatory activity, as well its role in the control of cortical excitability and plasticity explored by means of transcranial magnetic stimulation (TMS), and in hippocampal mouse slices in vitro.

RESULTS

CSF levels of RANTES were remarkably high only in active MS patients and were correlated with the concentrations of interleukin-1β. RANTES levels were associated with TMS measures of cortical synaptic excitability, but not with long-term potentiation (LTP)-like plasticity. Similar findings were obtained in mouse hippocampal slices in vitro, where we observed that RANTES enhanced basal excitatory synaptic transmission with no effect on LTP.

CONCLUSION

RANTES correlates with inflammation and synaptic excitability in MS brains.

The uniqueness of biobanks for neurological and psychiatric diseases: potentials and pitfalls

OBJECTIVES

Central nervous system (CNS) biobanks are facing difficult and specific challenges due to the sensitive issue of collecting specimens of the CNS, and especially the brain. At present, there is no global network/central database to serve researchers, clinicians and pharma companies, or to supply the special specimens and the accompanying data in sufficient numbers and detail, respectively. The main challenge/objective is to standardize and harmonize all the facets involved in CNS biobanking in order to maximize efficient sample collection.

METHODS

Since the number of CNS biospecimens stored in existing biobanks is relatively limited and the accompanying data are not always readily available and hard to identify, we propose using optimal procedures for handling and storage of these specimens, and the global standardization of the cliniconeuropathological diagnostic criteria.

RESULTS

One of the prominent achievements of the current global activity in brain tissue biobanks (BTB-banks) is the development of an inventory of international standards, available specimens and concomitant data, and national registries.

CONCLUSIONS

Taking into consideration the huge variety of the specimens stored in different repositories and the enormous differences in medicolegal systems and ethics regulations in different countries, we strongly recommend that healthcare systems and institutions who host BTB-banks make efforts to secure adequate funding for the infrastructure and daily activities. BTB-banks will refine standard operating procedures and their internal guides of best practices/codes of conduct. This in turn will enable the BTB-banks to share the collected specimens and data with the largest possible number of researchers, aiming at maximal scientific spin-off and advance of public health research.

Chemokine receptor V Δ32 deletion in multiple sclerosis patients in Csongrád County in Hungary and the North-Bácska region in Serbia

The roles of chemokine receptor V (CCR5) and its polymorphism, rs333 in multiple sclerosis (MS) are controversial. We investigated the receptor and its deletion in a large MS (428) and a numerous control (831) population in Csongrád County (Hungary) and North-Bácska (Serbia). Taqman probes firstly were used for the allele discrimination. There was no significant difference in genotype (OR=1.092, 95% CI=0.807-1.478, p=0.568 for wt/wt (wt=wild type allele) vs wt/Δ32, Δ32/Δ32 (Δ32=Δ32 base pair deletion allele)) or allele frequency (OR=0.914, 95% CI=0.692-1.207, p=0.525). Neither the deletion nor the wt allele affected the Expanded Disability Status Scale score or the age at onset. Our results indicate no association between the CCR5 Δ32 allele and MS.

The chemokine receptor CCR5 Δ32 allele in natalizumab-treated multiple sclerosis

OBJECTIVE

The chemokine receptor CCR5 may be important for the recruitment of pathogenic T cells to the CNS in multiple sclerosis (MS). We hypothesized that this chemokine receptor might still be important for T-cell migration during treatment with anti-very late antigen (VLA)-4 antibody. We therefore analysed whether natalizumab-treated MS patients carrying the CCR5 Δ32 deletion allele, which results in reduced expression of CCR5 on the cell surface, had lower disease activity.

METHODS

CCR5 Δ32 was analysed in 212 natalizumab-treated MS patients.

RESULTS

CCR5 Δ32 status had no significant impact on the frequency of relapses 1 year prior to natalizumab treatment or during the first 48 weeks of treatment. The multiple sclerosis severity score (MSSS) was significantly lower at baseline in patients carrying CCR5 Δ32 (P = 0.031).

CONCLUSIONS

CCR5 Δ32 is not associated with lower disease activity in MS patients treated with natalizumab. We found lower MSSS scores in patients carrying CCR5 Δ32 compared with the remaining patients, which is consistent with previous studies reporting an association with a more favourable disease course. Further studies are, however, needed before the relationship between CCR5 Δ32 and disease activity in MS can be definitely established.

HPA axis activity in multiple sclerosis correlates with disease severity, lesion type and gene expression in normal-appearing white matter

The hypothalamus-pituitary-adrenal (HPA) axis is activated in most, but not all multiple sclerosis (MS) patients and is implicated in disease progression and comorbid mood disorders. In this post-mortem study, we investigated how HPA axis activity in MS is related to disease severity, neurodegeneration, depression, lesion pathology and gene expression in normal-appearing white matter (NAWM). In 42 MS patients, HPA axis activity was determined by measuring cortisol in cerebrospinal fluid (CSF) and counting hypothalamic corticotropin-releasing hormone (CRH)-expressing neurons. Degree of neurodegeneration was based on levels of glutamate, tau and neurofilament in CSF. Duration of MS and time to EDSS 6 served as indicators of disease severity. Glutamate levels correlated with numbers of CRH-expressing neurons, most prominently in primary progressive MS patients, suggesting that neurodegeneration is a strong determinant of HPA axis activity. High cortisol levels were associated with slower disease progression, especially in females with secondary progressive MS. Patients with low cortisol levels had greater numbers of active lesions and tended towards having less remyelinated plaques than patients with high cortisol levels. Interestingly, NAWM of patients with high cortisol levels displayed elevated expression of glucocorticoid-responsive genes, such as CD163, and decreased expression of pro-inflammatory genes, such as tumor necrosis factor-α. Thus, HPA axis hyperactivity in MS coincides with low inflammation and/or high neurodegeneration, and may impact on lesion pathology and molecular mechanisms in NAWM and thereby be of great importance for suppression of disease activity.

Transcriptomics of cortical gray matter thickness decline during normal aging

INTRODUCTION

We performed a whole-transcriptome correlation analysis, followed by the pathway enrichment and testing of innate immune response pathway analyses to evaluate the hypothesis that transcriptional activity can predict cortical gray matter thickness (GMT) variability during normal cerebral aging.

METHODS

Transcriptome and GMT data were available for 379 individuals (age range=28-85) community-dwelling members of large extended Mexican American families. Collection of transcriptome data preceded that of neuroimaging data by 17 years. Genome-wide gene transcriptome data consisted of 20,413 heritable lymphocytes-based transcripts. GMT measurements were performed from high-resolution (isotropic 800 μm) T1-weighted MRI. Transcriptome-wide and pathway enrichment analysis was used to classify genes correlated with GMT. Transcripts for sixty genes from seven innate immune pathways were tested as specific predictors of GMT variability.

RESULTS

Transcripts for eight genes (IGFBP3, LRRN3, CRIP2, SCD, IDS, TCF4, GATA3, and HN1) passed the transcriptome-wide significance threshold. Four orthogonal factors extracted from this set predicted 31.9% of the variability in the whole-brain and between 23.4 and 35% of regional GMT measurements. Pathway enrichment analysis identified six functional categories including cellular proliferation, aggregation, differentiation, viral infection, and metabolism. The integrin signaling pathway was significantly (p<10(-6)) enriched with GMT. Finally, three innate immune pathways (complement signaling, toll-receptors and scavenger and immunoglobulins) were significantly associated with GMT.

CONCLUSION

Expression activity for the genes that regulate cellular proliferation, adhesion, differentiation and inflammation can explain a significant proportion of individual variability in cortical GMT. Our findings suggest that normal cerebral aging is the product of a progressive decline in regenerative capacity and increased neuroinflammation.

Demographic, genetic, and environmental factors that modify disease course

As with susceptibility to disease, it is likely that multiple factors interact to influence the phenotype of multiple sclerosis and long-term disease outcomes. Such factors may include genetic factors, socioeconomic status, comorbid diseases, and health behaviors, as well as environmental exposures. An improved understanding of the influence of these factors on disease course may reap several benefits, such as improved prognostication, allowing us to tailor disease management with respect to intensity of disease-modifying therapies and changes in specific health behaviors, in the broad context of coexisting health issues. Such information can facilitate appropriately adjusted comparisons within and between populations. Elucidation of these factors will require careful study of well-characterized populations in which the roles of multiple factors are considered simultaneously.

Genetics for understanding and predicting clinical progression in multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is a dys-immune disease of the central nervous system with highly variable and unpredictable long-term outcome.

STATE OF THE ART

In the early 1970s association between HLA alleles and MS was established. Very recently, the power of Genome Wide Association Studies (GWAS) enabled the identification of several loci involved in immune functions as genetic risk factors in MS. Recent data suggest that common genetic variations might modulate the clinical phenotype of MS through a regulation of key pathophysiological pathways.

PERSPECTIVES

Identification of modifier genes might offer an opportunity to explore new relevant therapeutic targets and early prognostic markers. To date, studies of modifier genes in MS are numerous but results are still unclear. This research field may now benefit from large cohorts of patients available for association studies.

CONCLUSION

In this context, we propose a review of epidemiological and association studies of genetic modifying effect in MS.

CCL5 induces a pro-inflammatory profile in microglia in vitro

The chemokine receptors CCR1, CCR2, CCR3, CCR5, and CXCR2 have been found to be expressed on microglia in many neurodegenerative diseases, such as multiple sclerosis and Alzheimer's disease. There is emerging evidence that chemokines, besides chemoattraction, might directly modulate reactive profiles of microglia. To address this hypothesis we have investigated the effects of CCL2, CCL3, CCL5, and CXCL1 on cytokine and growth factor production, NO synthesis, and phagocytosis in non-stimulated and lipopolysaccharide-stimulated primary rat microglia. The respective receptors CCR1, CCR5, and CXCR2 were shown to be functionally expressed on microglia. All tested chemokines stimulated chemotaxis whereas only CCL5 increased NO secretion and attenuated IL-10 as well as IGF-1 production in activated microglia. Based on these findings we propose that besides its chemoattractant function CCL5 has a modulatory effect on activated microglia.

Genetic correlations of brain lesion distribution in multiple sclerosis: an exploratory study

BACKGROUND AND PURPOSE

In MS, the total brain lesion volume and spatial distribution of lesions across the brain vary widely among individual patients. We hypothesized that spatial distribution may be partially driven by genetic predisposition, and we aimed to explore relations among candidate genes and the spatial distribution of white matter brain lesions in MS.

MATERIAL AND METHODS

Genotypes of 69 SNPs in 208 patients with MS were related to the spatial distribution of T2 brain lesions. Lesions were manually outlined on MR images, and binary lesion masks were produced and registered to a common space. With Randomise software, the lesion masks were related to genotype by using a voxelwise nonparametric GLM approach, followed by clusterwise analysis. We used a DNA chip with SNPs selected from the literature on MS susceptibility, severity, and phenotypes.

RESULTS

For 11 of these SNPs, 1 of the genotypes expressed significant clusters of increased or decreased lesion probability in varying, predominantly periventricular, brain regions. When we statistically controlled the voxelwise analyses for effects of total brain lesion volume, only 1 SNP remained significant: rs2227139, located within the MHC class II region. This SNP retained its periventricular cluster of significantly increased lesion probability for the heterozygote genotype.

CONCLUSIONS

Heterozygosity of rs2227139 (MHC class II region) is associated with increased right frontal periventricular lesion probability (P<.01). Ten other SNPs showed associations between genotype and spatial lesion distribution that are partly explained by total lesion volume.

TNF-α and IL-1β mediate Japanese encephalitis virus-induced RANTES gene expression in astrocytes

Infection with Japanese encephalitis virus (JEV) causes neuroinfection and neuroinflammation characterized by profound neuronal destruction/dysfunction, concomitant microgliosis/astrogliosis, and production of various molecules that initiate the recruitment of immune cells to the sites of infection. Previously, we reported that glial cells expressed RANTES (regulated upon activation, normal T cell expressed and secreted) with chemotactic activity in response to JEV infection. In this study, we further demonstrated that JEV-infected microglia had an additional activity in regulating RANTES production. Both astrocytes and microglia responded to JEV infection by releasing RANTES through a process likely related to viral replication. Independent of infectious virus, supernatants of JEV-infected microglia, but not JEV-infected astrocytes, caused additional RANTES production from astrocytes. Antibody neutralization studies suggested the potential involvement of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) in mediating additional RANTES production. Treatment of astrocyte cultures with TNF-α and IL-1β caused activation of several signaling molecules and transcription factors crucial to RANTES gene expression, including reactive oxygen species, extracellular signal-regulated kinase, NF-κB, and NF-IL6, increased RANTES gene promoter activity, and provoked RANTES production. As with RANTES, neutralization of bioactive TNF-α and IL-1β caused an attenuation of chemotactic activity from supernatants of mixed glia containing astrocytes and microglia during the course of JEV infection. In conclusion, TNF-α and IL-1β produced by JEV-infected microglia might trigger another mechanism which induces a secondary wave of RANTES gene expression by activating astrocytes. The released RANTES from glial cells might play a role in the recruitment of immune cells during JEV infection.

The chemokine receptor CCR5 in the central nervous system

The expression and the role of the chemokine receptor CCR5 have been mainly studied in the context of HIV infection. However, this protein is also expressed in the brain, where it can be crucial in determining the outcome in response to different insults. CCR5 expression can be deleterious or protective in controlling the progression of certain infections in the CNS, but it is also emerging that it could play a role in non-infectious diseases. In particular, it appears that, in addition to modulating immune responses, CCR5 can influence neuronal survival. Here, we summarize the present knowledge about the expression of CCR5 in the brain and highlight recent findings suggesting its possible involvement in neuroprotective mechanisms.

Role of platelets in neuroinflammation: a wide-angle perspective

OBJECTIVES

This review summarizes recent developments in platelet biology relevant to neuroinflammatory disorders. Multiple sclerosis (MS) is taken as the "Poster Child" of these disorders but the implications are wide. The role of platelets in inflammation is well appreciated in the cardiovascular and cancer research communities but appears to be relatively neglected in neurological research.

ORGANIZATION

After a brief introduction to platelets, topics covered include the matrix metalloproteinases, platelet chemokines, cytokines and growth factors, the recent finding of platelet PPAR receptors and Toll-like receptors, complement, bioactive lipids, and other agents/functions likely to be relevant in neuroinflammatory diseases. Each section cites literature linking the topic to areas of active research in MS or other disorders, including especially Alzheimer's disease.

CONCLUSION

The final section summarizes evidence of platelet involvement in MS. The general conclusion is that platelets may be key players in MS and related disorders, and warrant more attention in neurological research.

HIV Coreceptors and Their Roles in Leukocyte Trafficking During Neuroinflammatory Diseases

Due to the increasing resistance of HIV-1 to antiretroviral therapies, there has been much emphasis on the discovery and development of alternative therapeutics for HIV-1-infected individuals. The chemokine receptors CXCR4 (Bleul et al. 1996a; Feng et al. 1996; Nagasawa et al. 1996; Oberlin et al. 1996) and CCR5 (Alkhatib et al. 1996; Deng et al. 1996; Dragic et al. 1996) were identified as target molecules from the time their role as coreceptors for HIV-1 entry into leukocytes was first discovered 10 years ago. Initial studies focused on the use of the chemokine ligands, or altered derivatives, of CXCR4 and CCR5 to prevent the entrance of HIV-1 into immune cells (Schols 2006). While these studies showed some initial promise, there was evidence of significant caveats to their use, including selection of alternative coreceptor utilizing strains (Marechal et al. 1999; Mosier et al. 1999) and the potential to cause inflammatory side effects. These data prompted the development and study of small molecule inhibitors of CXCR4 and CCR5, which have also been used to examine the roles of these molecules in a variety of inflammatory and infectious diseases.

Brain imaging of multiple sclerosis: the next 10 years

MR imaging has had a major impact on understanding the dynamic neuropathologic findings of multiple sclerosis (MS), early diagnosis of the disease, and clinical trial conduct. The next 10 years can be expected to see further advances with a greater emphasis on large multicenter studies, new techniques and hardware allowing greater imaging sensitivity and resolution, and the exploitation of positron emission tomography molecular imaging for MS. The impact should be felt with a new emphasis on gray matter disease and processes of repair. With new ways of monitoring the disease, new treatment targets should become practical, helping to translate advances in the understanding of immunology and regenerative medicine into novel therapies.

Association of CCR5-delta32 mutation with reduced risk of nonatopic asthma in Slovenian children

Asthma is one of the most common chronic diseases of childhood. Asthma results from the interaction of several genes and environmental influences. Viral infections are common triggers of asthma attacks, especially in nonatopic asthmatics. CCR5 is a chemokine receptor involved in the immune response against a number of viruses. A 32 base pair deletion (delta32) in the CCR5 receptor gene causes loss of gene function and is associated with several chronic diseases due to the resulting altered immunity. The results of the association studies exploring the role of the CCR5 receptor gene in asthma pathogenesis are contradictory. We studied 111 children aged between 5 and 18 years with mild or moderate persistent asthma; 75 of them were atopic and 36 had nonatopic asthma. We carried out allergy and spirometry tests, a bronchoprovocation test with methacholine and performed measurement of exhaled nitric oxide and genotyping for CCR5-delta32 mutation. Compared with 365 nonatopic, nonasthmatic controls we found significantly lower CCR5-delta32 allelic frequency in nonatopic asthmatics (p = 0.016, OR 0.139, 95% CI 0.02 to 0.984) but not in atopic asthmatics. CCR5-delta32 mutation protects against nonatopic asthma. This association offers new insights into the pathogenesis of an important asthma phenotype and could serve as useful information for the future research of new asthma management strategies.

Pediatric multiple sclerosis

Diagnosing multiple sclerosis (MS) in a child is challenging because of the limited diagnostic criteria and their overlap with acute disseminated encephalomyelitis. Pediatric-onset MS patients are more likely to be male, have seizures, and have brainstem and cerebellar symptoms than adults, and are less likely to have spinal cord symptoms than adults. They mostly experience a relapsing-remitting course. Their initial brain MRI shows more frequent involvement of the posterior fossa, less well-defined ovoid lesions, and more confluent lesions that decrease over time in patients with prepubertal onset, making early diagnosis even more difficult. Although disability progression is slower than in adults, pediatric onset MS leads to significant disability at a younger age and may be worse in non-white patients (up to 50% in North America). The rareness of pediatric-onset MS has precluded enrollment in clinical trials. Thus, children are receiving off-label adult therapies without clear evidence of their effectiveness and limited knowledge of their tolerability.

Decreased spinal cord opioid receptor mRNA expression and antinociception in a Theiler's murine encephalomyelitis virus model of multiple sclerosis

Multiple sclerosis patients typically experience increased pain that is relatively insensitive to opiate treatment. The mechanistic basis for this increased nociception is currently poorly understood. In the present study, we utilized the Theiler's murine encephalomyelitis virus (TMEV) model of MS to examine possible changes in spinal cord opioid receptor mRNA over the course of disease progression. TMEV infection led to significantly decreased mu, delta and kappa opioid receptor mRNA expression as analyzed by quantitative real-time PCR in both male and female mice at days 90, 150 and 180 post-infection (PI). Since opioid receptor mRNA expression decreased in TMEV mice, we examined whether opiate analgesia is also altered. TMEV infected female mice had significantly decreased opiate analgesia in thermal nociceptive tests beginning at day 90 PI, while TMEV-infected male mice did not display significantly decreased opiate analgesia until day 120 PI. The novel finding that opioid receptor expression is significantly decreased in the spinal cord of TMEV mice could explain the increased nociception and loss of opiate analgesia observed in both TMEV mice and multiple sclerosis patients.