Biomedical subjects

Hans Link

Publications and source records attributed to Hans Link.

At least 19 recordsLinked to original sources

PubMed2006

Oligoclonal bands in multiple sclerosis cerebrospinal fluid: an update on methodology and clinical usefulness.

Two or more oligoclonal IgG bands (OB) detected by separation of cerebrospinal fluid (CSF) proteins while not demonstrable in corresponding serum reflect a local B-cell response accompanying central nervous system (CNS) inflammation. Using optimized, standardized methodology, preferentially protein separation by isoelectric focusing followed by immunoblotting, more than 95% of patients with multiple sclerosis (MS) have CSF OB of IgG class not detectable in serum, thereby providing powerful evidence for the diagnosis of MS. Once present, CSF OB persists in the individual patient irrespective of MS course or therapy. Because of the high sensitivity of CSF OB in MS as well as its high specificity in the appropriate clinical setting, examination of CSF for OB of IgG class can be strongly recommended to obtain support for the diagnosis of MS and identify patients with clinically isolated syndrome (CIS) at increased risk of developing MS. The IgG index equal to CSF/serum IgG:CSF/serum albumin is elevated in about 70% of MS patients, but rarely in CSF OB-negative MS. Because of lower diagnostic sensitivity, IgG index cannot be recommended as replacement of CSF OB in the diagnosis of MS but, when elevated, as additional evidence for an augmented B-cell response within the CNS that is compatible with MS. Although the clinical picture as well as findings from magnetic resonance imaging of the brain and spinal cord are essential for an MS diagnosis, this should be re-evaluated in CSF OB-negative patients, keeping in mind the many disease entities imitating MS. Recommended diagnostic criteria for MS must include definitions of the role of lumbar puncture and of clearly specified, optimized and standardized routine CSF investigations including for the presence of CSF IgG OB. There is a need for concerted long-term follow-up studies of the subgroup of MS patients without CSF OB regarding e.g. prognostic and immunologic features. For inclusion in trials of disease-modulating drugs, it is recommended that patients with MS or CIS are selected regarding presence vs. absence of CSF OB. Development and evaluation of new technologies to define local vs. systemic B-cell responses in patients with MS or CIS vs. patients with other inflammatory neurological diseases should shed new light on the role of CSF OB, which remains enigmatic.

Animals↗

PubMed2005

CD24 and myosin light polypeptide 2 are involved in prevention of experimental autoimmune encephalomyelitis by myelin basic protein-pulsed dendritic cells.

We previously demonstrated that injection of myelin basic protein-pulsed (MBP-pulsed)--but not of unpulsed--autologous bone marrow-derived dendritic cells (DC) efficiently prevents experimental autoimmune encephalomyelitis (EAE) in Lewis rats. To define the molecules involved, we used 3 groups of rats pretreated subcutaneously with MBP-DC, or unpulsed DC, or PBS (control EAE). Four weeks later, all rats were immunized with encephalitogenic MBP peptide and adjuvant. Microarray analyses were done to screen for genes that differ among the 3 groups. Based on microarray analysis data, we used real-time PCR to measure expression of six probably involved genes in draining lymph node cells obtained on day 0, day 7 and day 14 post immunization (p.i.). Two of these 6 genes were consistently altered in both microarray analyses and RT-PCR. They are CD24 antigen being persistently low, and myosin light polypeptide 2 (Myl2) being high in the acute immune response in MBP-DC pretreated rats that develop resistance to EAE. These two genes could be targeted to treat EAE and, possibly, multiple sclerosis.

Animals↗

PubMed2005

Anti-inflammatory nuclear receptor superfamily in multiple sclerosis patients from Sardinia and Sweden.

Several nuclear hormone receptors have been associated with inflammatory reactions. Particularly, liver X receptors (LXRs) have recently been identified as key transcriptional regulators of genes involved in lipid homeostasis and inflammation. LXRs are negative regulators of macrophage inflammatory gene expression. Multiple sclerosis (MS), a demyelinating disease of the central nervous system of unknown cause, is characterized by recurrent inflammation involving macrophages and their inflammatory mediators. Sweden belongs to the countries with a high MS incidence. In Italy, the MS incidence is lower, except on the island of Sardinia where the incidence is even higher than in Sweden. Subjects from Sardinia are ethnically more homogeneous, and differ from Swedes also regarding genetic background and environment. We studied mRNA expression of several nuclear hormone receptors in blood mononuclear cells (MNC) from female patients with untreated relapsing-remitting MS from Sassari, Sardinia, and Stockholm, Sweden. Sex- and age-matched healthy controls (HC) were from both areas. mRNA expression was evaluated by quantitative real-time PCR. We found altered mRNA expression of LXRs, estrogen receptors (ERs), and androgen receptor (AR) in MS. mRNA expression of both LXRalpha and LXRbeta is lower in MS from Stockholm but not from Sassari. In particular, LXRalpha mRNA expression was significantly lower in MS from Stockholm as compared with all groups in the study including MS from Sassari. Low levels of ERalpha mRNA are seen in MS from both Stockholm and Sassari. The splice variant ERbetacx showed significantly higher mRNA expression in MS from Sassari and Stockholm as compared with corresponding HC. In particular, ERbetacx mRNA in MS from Sassari was remarkably higher as compared with all other groups in the study. Higher levels of AR mRNA are present in HC from Sassari. The findings indicate that the expression levels of anti-inflammatory nuclear receptor superfamily genes in MS appear to reflect both ethnic and environmental influences.

Adult↗

PubMed2005

Long-term effects of IFN-gamma, IL-10, and TGF-beta-modulated dendritic cells on immune response in Lewis rats.

Increasing data have shown that IFN-gamma, IL-10, and TGF-beta-modulated dendritic cells (DC) provide a promising strategy in treatment of experimental allergic encephalomyelitis and experimental autoimmune myasthenia gravis through different manner. To explore the immune response status after long-term application of these cytokine-modulated-DC, Lewis rats were injected subcutaneously into naive DC and IFN-gamma, IL-10, and TGF-beta-modulated DC (i.e., IFN-gamma-DC, IL-10-DC, and TGF-beta-DC) at does of 1 x 10(6) cells/rat every month for continuous 18 months, respectively. No rats suffered from decreased vigor and activity as well as cachectic condition during 18-month observation, and no rats had body-weight loss after 18-month treatment. Exploratory laparectomy did not find any tumor in all rats. IL-10-DC and TGF-beta-DC resulted in lower nonspecific (Con A-induced) and antigen specific (ovalbumin-stimulated) spleen mononuclear cells proliferation, accompanied by lower levels of IFN-gamma, IL-10, and TNF-alpha. On the contrary, IFN-gamma-DC did not suppress cell proliferation and IFN-gamma and IL-10 production except only slightly decreased TNF-alpha levels. These results suggest that IFN-gamma-DC seems to be a more ideal candidate in the treatment of autoimmune diseases without suppressing immune response.

Animals↗

PubMed2005

Immunological heterogeneity of multiple sclerosis in Sardinia and Sweden.

Subjects from Sardinia, Italy, are relatively homogeneous compared to Swedes. Although ethnically distant, both populations have similarly high multiple sclerosis (MS) incidence rates. Pro- and anti-inflammatory cytokines and their receptors, signalling molecules and other immune response-associated factors might influence MS pathogenesis, though definite proof is missing. The study of populations with similar MS incidence but different genetic and environmental background could make possible the definition of factors that relate to such background differences. We selected untreated female MS patients from Sassari, Sardinia, and Stockholm, Sweden, and corresponding sex- and age-matched healthy controls (HC), to study blood mononuclear cells (MNC) for mRNA expression of 20 immune response-related genes considered relevant in MS, employing real-time PCR. Higher expression of IL-12p40 mRNA was confined to MS from both Sassari and Stockholm, compared to corresponding HC. MS patients from Sassari, but not Stockholm, expressed higher TNF-alpha compared to corresponding HC. MS patients from Stockholm, but not Sassari, expressed higher IL-6. Indoleamine 2,3 dioxygenase (IDO), a molecule necessary in tolerance induction, was lower in MS from Stockholm compared to corresponding HC. This was not observed in Sassari. No differences were detected for other members of the IL-12 family, other Th1 and Th2 cytokines, and the signalling molecules Stat 4 and 6. The results corroborate a pro-inflammatory state in MS as reflected by high expression of IL-12, TNF-alpha and IL-6, although the extent of expression of TNF-alpha, IL-6 and IDO differs between strictly matched MS patients from different high-incidence areas. This might result from genetic and/or environmental differences. They may account for some of the discrepancies regarding immune response-related molecules previously reported in MS. In conclusion, a pro-inflammatory state exists in MS patients from Sassari as well as Stockholm. The changes of pro-inflammatory and other immune response-related variables differ however between the two MS populations. This may be attributed to the genetic and/or environmental background.

Adult↗

PubMed2005

Autoantigen-pulsed dendritic cells constitute a beneficial cytokine and growth factor network in ameliorating experimental allergic encephalomyelitis.

Injection of myelin basic protein (MBP)-pulsed dendritic cells (DC) into healthy rats, as we reported before and observed in this study, did not induce clinical experimental allergic encephalomyelitis (EAE), but effectively protected the rats from subsequent EAE induction. The mechanisms by which MBP-pulsed DC mediate immune protection are not completely understood. In the present study, we mainly explored the dynamic change of cytokine and growth factor mRNA expression in spinal cords after subcutaneous injection of MBP-pulsed and unpulsed DC. The expression of interleukin (IL)-1, interferon-gamma and tumour necrosis factor-alpha as well as programmed death ligand (PDL)-1, PDL-2, signal transducer and activator of transcription (STAT)4, STAT6, matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloproteinases (TIMP)-2 was increased on day 0 postimmunization (p.i.). The increase of IL-12 expression was observed on day 7 p.i., while the increase of IL-10 expression mainly occurred on day 14 p.i. Except downregulation of insulin-like growth factor-1, the expression of brain-derived neurotrophic factor, ciliary neurotrophic factor, fibroblast growth factor (FGF)-2 and platelet-derived growth factor (PDGF)-B/C as well as nerve growth factor receptor (NGF-R), FGF receptor, PDGF-R-alpha and beta was elevated on day 0 p.i., while the increase of TIMP and NGF was observed on days 0 and 7 p.i. There were no significant differences on MMP-2, spinal cord-derived growth factor and PDGF-A mRNA expression. In line with the suppression of EAE induced by MBP-pulsed DC, the dynamic change of cytokines and growth factors in spinal cords should constitute a beneficial microenvironment against EAE.

Animals↗

PubMed2004

Efficacy of peripheral tolerance induced by dendritic cells is dependent on route of delivery.

Previous studies have demonstrated that the route of delivery of dendritic cells (DC) is an important variable in eliciting anti-tumor immunity. In contrast, little is known about different routes of DC administration to influence peripheral tolerance in autoimmune diseases. Here we compared therapeutic effect of splenic IFN-gamma-modified-DC (IFN-gamma-DC) in actively induced experimental allergic encephalomyelitis (EAE) by different routes of DC delivery. Following subcutaneous (s.c.) injection, IFN-gamma-DC effectively suppressed clinical signs of EAE, whereas intravenous (i.v.) injection did not inhibit clinical signs of EAE. Compared to s.c. injection, i.v. injection of IFN-gamma-DC failed to mediate T cell responses, but stimulated anti-MBP antibody production and upregulated pro-inflammatory IL-1beta, IFN-gamma and TNF-alpha as well as RANTES expression which may contribute to the accumulation of inflammatory cells within the central nervous system. These results suggest that the administration route of DC should be considered as an important factor for DC-based immunotherapy in autoimmune diseases.

Animals↗

PubMed2004

Laquinimod (ABR-215062) suppresses the development of experimental autoimmune encephalomyelitis, modulates the Th1/Th2 balance and induces the Th3 cytokine TGF-beta in Lewis rats.

The new orally active drug laquinimod (ABR-215062) was evaluated in experimental autoimmune encephalomyelitis (EAE) in the Lewis rat. EAE shares important immunological and clinical features with multiple sclerosis (MS). Doses of 16, 1.6 and 0.16 mg/kg/day laquinimod dose-dependently inhibited disease and showed better disease inhibitory effects as compared to roquinimex (Linomide). Furthermore, laquinimod inhibited the inflammation of both CD4+ T cells and macrophages into central nervous tissues, i.e. the spinal cord. It also changed the cytokine balance in favour of TH2/TH3 cytokines IL-4, IL-10 and TGF-beta. Laquinimod therefore represents a new orally active immunoregulatory drug without general immunosuppressive properties with a potential for the treatment of severe autoimmune diseases like MS.

Animals↗

PubMed2004

Dendritic cells activate autologous T cells and induce IL-4 and IL-10 production in myasthenia gravis.

Dendritic cells (DC), as initiators and orchestrators of immune responses, control both naive and primed T cell responses. Depending on their maturation stage, DC promote immunity or tolerance. Here we investigated (1) the phenotype and cytokine secretion patterns of IL-10-modulated immature DC (IL-10-DC) and lipopolysaccharide (LPS)-driven mature DC (LPS-DC) in comparison with unmodulated immature DC (imDC) and (2) the effects of IL-10-DC, and of LPS-DC, vs. imDC on autologous T cell responses in patients with myasthenia gravis (MG) compared with healthy controls (HC). All three types of DC derived from MG significantly increased the levels of CD4+CD25+ T cells and of their subfraction expressing CD69, when compared to DC derived from HC. IL-10-DC induced production of IL-10 and IL-4 by T cells from MG patients, but only IL-10 production from HC. LPS-DC activated autologous T cells as reflected by augmented CD25, CD69 and CTLA-4 expression on CD4+ T cells, without differences between MG and HC. This was associated with increased production of both Th1 (IFN-gamma) and Th2 (IL-10 and IL-4) cytokines by T cells. These results indicate that DC-induced activation of autologous T cells is more pronounced in MG than in HC. In addition, DC-induced T cell responses in MG vs. HC are more Th2-prone.

Adult↗

PubMed2004

Dendritic cells exposed to estrogen in vitro exhibit therapeutic effects in ongoing experimental allergic encephalomyelitis.

Immunomodulatory effects of estrogen have been demonstrated by clinical and experimental observations, but the mechanisms by which estrogen exhibits the effects remain to be defined. One possible mechanism by which estrogen inhibits the development of experimental allergic encephalomyelitis (EAE), a commonly used model of multiple sclerosis (MS) in humans, is over the functions of dendritic cells (DC). Here, we describe that splenic DC from Lewis rats obtained on day 12 post-immunization (p.i.) with myelin basic protein (MBP) encephalitogenic peptide 68-86+Freund's complete adjuvant (FCA), after being exposed in vitro 17beta-estradiol, exhibited therapeutic effects on acute EAE when injected subcutaneously on day 5 p.i. Blood mononuclear cells (MNC) were isolated from thus treated rats on day 12 p.i. Administration of estrogen-exposed DC prevented the expansion of CD4+ T cells and increased proportions of regulatory T cells producing IL-10 and CD4+CD28- suppressor T cells, accompanied with increased IL-10 and IFN-gamma, and reduced TNF-alpha production. Infiltrates of CD68+ macrophages within the central nervous system and MBP 68-86-induced T cell proliferation were inhibited in rats injected with estrogen-exposed DC compared to rats injected with naive DC. Estrogen up-regulated the expression of indoleamine 2,3-dioxygenase, which promotes tolerogenic properties of DC. The results suggest that in vitro exposure of DC to estrogen modulates DC functions and results in a therapeutic effect of DC.

Adjuvants, Immunologic↗

PubMed2004

Protective potential of experimental autoimmune myasthenia gravis in Lewis rats by IL-10-modified dendritic cells.

Dendritic cells (DC) are usually regarded as antigen-presenting cells (APC) involved in T cell activation, but DC also directly or indirectly affect B cell function, antibody synthesis and isotype switch. In this study, we explore potential of DC-based immunotherapy in ongoing experimental autoimmune myasthenia gravis (EAMG) in Lewis rats, which is mediated by anti-acetylcholine receptor (AChR) antibodies. Spleen DC were isolated from onset of Lewis rat EAMG on day 39 post immunization (p.i.), exposed in vitro to IL-10 and then injected intraperitoneally into ongoing EAMG Lewis rats at dose of 1 x 10(6) cells/rat on day 5 p.i. with AChR + complete Freund's adjuvant. IL-10-modified DC resulted in lower clinical scores, less body weight loss, lower numbers of anti-AChR IgG antibody-secreting cells and lower affinity of anti-AChR antibodies in rats receiving IL-10-modified DC, accompanied with lower expression of CD80 and CD86 and lower lymphocyte proliferation among lymph node mononuclear cells compared with control EAMG rats. Lower levels of IL-10 and IFN-gamma were also found in the supernatants of AChR-stimulated lymph node MNC culture in rats receiving IL-10-modified DC. These results demonstrate that IL-10-modified DC induced hypo-responsiveness by down-regulating co-stimulatory molecules, and reduced production of anti-AChR antibodies possibly by inhibiting IL-10 production. Importantly, this procedure that autologous DC from EAMG were adopted to treat ongoing EAMG is more close to clinical trial in human, encouraging future evaluation in human myasthenia gravis.

Animals↗

PubMed2004

Antigen-specific T cell functions are suppressed over the estrogen-dendritic cell-indoleamine 2,3-dioxygenase axis.

Estrogen results in the suppression of experimental allergic encephalomyelitis (EAE), a frequently used experimental animal model of multiple sclerosis (MS). The mechanism by which estrogen acts in diseases with an autoimmune background is less clear. Here, we used splenic dendritic cells (DC) from the Lewis rats EAE model as target cells, and explored the pathway of estrogen in immune modulation. Estrogen did not affect the expression of MHC class II, CD80 and CD86 by DC, but inhibited the ability of DC to stimulate T cell proliferation and production of both Th1 and Th2 cytokines. This was accompanied by increased T cell apoptosis. Estrogen up-regulated DC to express indoleamine 2,3-dioxygenase (IDO) which can limit T cell responses. The effects of estrogen-exposed DC on T cell proliferation and apoptosis were partly abolished by addition of an IDO inhibitor (1-methyl-dl-tryptophan, 1-MT), indicating that estrogen-exposed DC induced IDO-dependent T cell suppression. Our data support the hypothesis that the estrogen-induced suppression of EAE, as well as the reduction in number of MS relapses observed during pregnancy, may be related to the estrogen-DC-IDO axis. This observation could open up a novel therapeutic target for influencing the course of MS and other diseases with an autoimmune diseases background.

Animals↗

PubMed2004

Circulating CD4+CD25+ T regulatory cells are not altered in multiple sclerosis and unaffected by disease-modulating drugs.

Experimental animal models for autoimmunity have demonstrated the existence and crucial role of CD4(+)CD25(+) T regulatory (Tr) cells in suppressing autoreactive T cells and promoting peripheral tolerance. Recent in vitro functional studies showed that Tr cells are enriched in the CD25(high) cell population among CD4(+) T cells, and that they totally inhibit proliferation and cytokine secretion by CD4(+) T cells. It is not yet known if circulating Tr cells are involved in multiple sclerosis (MS). This study was done firstly to determine whether alterations of the CD4 (+) CD25(high) T cells occur in MS, examining their frequencies. As it was reported that the suppressive activity of CD4(+)CD25(+) Tr cells is mainly through cell surface contact pathway, we secondly analyzed the expression of the functionally important cell surface molecules of CD4(+)CD25(high) Tr cells. Two- or three-colour flow cytometry was used to identify and quantify CD4(+)CD25(+) Tr cells and CD4(+)CD25(high) Tr cells among blood CD4(+) T cells in MS patients without treatment vs. patients treated with either interferon-beta (IFN-beta) or glatiramer acetate (GA) or IFN-beta + GA in combination vs. healthy controls (HC). Expression of functionally important surface molecules CD45RO, CD69, CD95, HLA-DR, and intracellular CTLA-4 and IL-10 production by CD4(+)CD25(high) Tr cells were investigated. CD4(+)CD25(+) T cells constituted around 6% of CD4(+)T cells in all MS patient groups, and 7% in HC. There were also no changes in the proportions of CD4(+)CD25(+) Tr cells and CD4(+)CD25(high) Tr cells in a longitudinal follow-up of MS patients before and during IFN-beta treatment. Frequencies of circulating CD4(+)CD25(high)Tr cells among CD4(+) T cells were also similar and their surface or intracellular molecular expression did not vary in MS patients, irrespective of treatment, compared to HC. This study suggests that levels of circulating CD4(+)CD25(+) Tr cells and CD4(+)CD25(high) Tr cells are not altered in MS, and are unaffected by substances currently used to modulate the disease.

Adult↗

PubMed2004

Therapeutic potential of IFN-gamma-modified dendritic cells in acute and chronic experimental allergic encephalomyelitis.

Dendritic cells (DC) are antigen-presenting cells specialized to regulate immune responses. DC not only control immunity, but also maintain tolerance to self-antigens-two complementary functions that would ensure the integrity of the organism in an environment full of pathogens. Here we report that splenic DC that had been exposed in vitro to IFN-gamma (IFN-gamma-DC) exhibit therapeutic potential on acute experimental allergic encephalomyelitis (EAE) in Lewis rats, and on chronic-relapsing EAE in B6 and SJL/J mice. During incipient EAE [day 5 post-immunization (p.i.) in rats, day 7 p.i. in mice], IFN-gamma-DC were injected s.c. Severity of clinical signs of EAE was dramatically inhibited in animals injected with IFN-gamma-DC, showing normal magnetic resonance imaging (MRI) of the spinal cord and brain. In contrast, the EAE rats receiving PBS or naive DC had severe clinical signs with multiple and extensive MRI lesions in the spinal cord and brain. IFN-gamma-DC triggered an antigen-specific IFN-gamma production, and induced apoptosis of CD4(+) T cells possibly through DC expressing indoleamine 2,3-dioxygenase and/or an IFN-gamma-dependent pathway. As a result, infiltration of macrophages and CD4(+) T cells within the spinal cords was dramatically reduced in animals injected with IFN-gamma-DC as compared to animals injected with PBS or naive DC. This approach may represent a novel possibility of individualized immunotherapy using autologous, in vitro modified DC as a complement to conventional therapy in multiple sclerosis and other diseases with an autoimmune background.

Acute Disease↗

PubMed2004

Multiple sclerosis: expression of CD1a and production of IL-12p70 and IFN-gamma by blood mononuclear cells in patients on combination therapy with IFN-beta and glatiramer acetate compared to monotherapy with IFN-beta.

Current therapy of multiple sclerosis (MS) with interferon-beta (IFN-beta) or glatiramer acetate (GA) has modest effects on the course of MS. Both compounds affect several immune variables, like expression of cell surface molecules and cytokine levels. Here we compared untreated MS, therapy with IFN-beta alone and combined with GA, and healthy controls (HC), regarding expression on HLA-DR+ blood mononuclear cells (MNC) of CD1a that is a cell surface molecule with capacity to present glycolipids to T cells, and of CD80 and CD86 which are costimulatory molecules that activate Th1 and Th2 responses. Cytokine production by MNC was also measured. Flow cytometry and ELISA were used. Cross-sectional comparisons revealed that untreated MS patients had higher CD1a+ HLA-DR+ MNC and lower IL-10 production compared to patients treated with IFN-beta or IFN-beta+GA or HC. Untreated MS patients also had higher spontaneous IFN-gamma and IL-12p70 production compared to MS patients treated with IFN-beta+GA or HC, but not when compared to MS patients on monotherapy with IFN-beta. Low CD1a+ HLA-DR+ MNC and low spontaneous production of IL-12p70 and IFN-gamma were more pronounced in patients treated with IFN-beta+GA than with IFN-beta alone. In order to clarify whether these changes reflect disease activity or treatment effects, we performed a follow up study. Nineteen MS patients with disease progression, despite monotherapy with IFN-beta for more than one year; were re-examined after one to three and four to six months of treatment with IFN-beta+GA. This combination therapy was associated with normalization of CD1a+ HLA-DR+ MNC, IL-12p70 and IFN-gamma. It remains to be shown whether these immunological changes imply a clinical benefit. Follow up studies of immune variables versus clinical effects during combined therapy of MS with IFN-beta+GA are ongoing.

Adult↗

PubMed2003

Decreased levels of CD95 and caspase-8 mRNA in multiple sclerosis patients with gadolinium-enhancing lesions on MRI.

Magnetic resonance imaging (MRI) allows examining inflammation and central nervous system (CNS) tissue damage in patients suffering from multiple sclerosis (MS), a demyelinating disease of the CNS. Using real-time PCR, we quantified mRNA levels of apoptosis regulators CD95, CD95 ligand, caspase-8, -10 and cellular FLICE-inhibitory protein (cFLIP), and cytokines IL-10 and TNF-alpha in blood mononuclear cells of MS patients at the time of MRI examination. Patients with detectable gadolinium-enhancing lesions had lower expression of CD95 and caspase-8 (P<0.05). Lesion load and brain atrophy did not correlate with expression levels of any of the target molecules studied. Disease duration correlated positively with both FLIP/caspase-8 and CD95/CD3 ratios (P<0.05). These results support the notion that the CD95-dependent pathway plays a complex role in the regulation of survival of activated immune cells in MS.

Adult↗

PubMed2003

Effect of glatiramer acetate (Copaxone) on CD4+CD25high T regulatory cells and their IL-10 production in multiple sclerosis.

CD4(+)CD25(high) T regulatory (Tr) cells, representing high IL-2 receptor alpha chain expressing cells, have been shown to inhibit proliferation and cytokine secretion by CD4(+) T cells that are assumed to represent important effector cells in auto-aggressive immunity. Tr cells may therefore be considered of importance in the pathogenesis of multiple sclerosis (MS). Glatiramer acetate (GA; Copaxone) is approved as a disease-modulating agent that ameliorates the course of MS. The goal of this study was to examine in vitro effects of GA on Tr cells from MS patients subgrouped according to treatment without or with disease-modulating drugs, and healthy controls (HC). Three-colour flow cytometry was used to investigate in vitro influence of GA, and of the encephalitogenic myelin basic protein (MBP) peptide 83-89 as control, on the blood Tr cell proportion and on their functionally important cell surface molecules CD45RO, CD69, CD95 and HLA-DR, and on intracellular CTLA-4 and IL-10. Irrespective of exposure to GA or MBP((83-99)), levels of blood Tr cells expressing HLA-DR remained low in untreated MS patients and HC compared to the three treated MS patient groups. In vitro exposure to GA resulted in elevated levels of IL-10 producing Tr cells in all MS patient groups irrespective of receiving treatment as well as in HC. Exposure to GA or MBP((83-99)) had no effects on levels of Tr cells expressing other above-mentioned molecules. We conclude that GA induces elevated IL-10 production by Tr cells that is uniform and independent of ongoing MS treatment with IFN-beta or GA or IFN-beta+GA.

Adjuvants, Immunologic↗

PubMed2003

Induction of peripheral tolerance to experimental autoimmune myasthenia gravis by acetylcholine receptor-pulsed dendritic cells.

Dendritic cells (DC) are usually regarded as antigen-presenting cells involved in T cell activation, but DC also directly and indirectly affect B cell activation, antibody synthesis, and isotype switch. In the present study, bone marrow (BM)-derived DC from healthy rats were pulsed in vitro with acetylcholine receptor (AChR) and injected subcutaneously into healthy Lewis rats. No clinical signs of the first phase of experimental autoimmune myasthenia gravis (EAMG) were observed during 3 weeks of observation. Upon immunization with AChR and complete Freund's adjuvant, the rats that had received AChR-pulsed DC did not develop clinical EAMG. This tolerance of rats injected with AChR-pulsed DC was associated with reduced expression of B cell-activating factor (BAFF) and by reduced numbers of B cells among splenic mononuclear cells (MNC) compared to rats injected with medium or unpulsed DC. Anti-AChR IgG antibody-secreting cells were decreased, while the ratio of IgG1:IgG2b isotypes was enhanced in rats treated with AChR-pulsed DC compared to control EAMG rats. These results demonstrate that AChR-pulsed DC induce peripheral tolerance to EAMG by possibly inhibiting the expression of BAFF and production of anti-AChR antibodies, providing a possible potential for immunotherapy of antibody-mediated autoimmune diseases.

Animals↗