Spatially multiplexed single-molecule translocations through a nanopore at controlled speeds

In current nanopore-based label-free single-molecule sensing technologies, stochastic processes influence the selection of translocating molecule, translocation rate and translocation velocity. As a result, single-molecule translocations are challenging to control both spatially and temporally. Here we present a method using a glass nanopore mounted on a three-dimensional nanopositioner to spatially select molecules, deterministically tethered on a glass surface, for controlled translocations. By controlling the distance between the nanopore and glass surface, we can actively select the region of interest on the molecule and scan it a controlled number of times and at a controlled velocity. Decreasing the velocity and averaging thousands of consecutive readings of the same molecule increases the signal-to-noise ratio by two orders of magnitude compared with free translocations. We demonstrate the method's versatility by assessing DNA-protein complexes, DNA rulers and DNA gaps, achieving down to single-nucleotide gap detection.

Kinetics of expression of costimulatory molecules and their ligands in murine relapsing experimental autoimmune encephalomyelitis in vivo

We studied the kinetics of expression of costimulatory molecules and cytokines in the central nervous system (CNS) in murine relapsing experimental autoimmune encephalomyelitis (EAE). During the natural course of EAE, B7-2 expression in the CNS correlated with clinical signs, while B7-1 was exclusively expressed during remissions. Interestingly, B7-1 was expressed on infiltrating mononuclear cells as well as neuronal cells in the CNS. In the periphery, B7-1 expression on APCs peaked with clinical disease but decreased on T cells. CD28 and CTLA4 molecules, the two known ligands for B7-1 and B7-2, had distinct expression patterns in the CNS; CD28 was highly expressed and correlated with B7-2 expression on APCs (macrophages/microglia as well as astrocytes) and with the clinical signs of EAE. CTLA4, on the other hand, was expressed by substantially fewer cells during the effector phase of disease and peaked during remission, which is consistent with the emerging role of this molecule in the termination of immune responses. The expression of CD40 and CD40L in the CNS was increased during clinical attacks. The expression of IL-12, IFN-gamma, and TNF-alpha correlated with disease activity and severity, while TGF-beta was the only factor that was up-regulated during the recovery phase. Interestingly, TGF-beta was also expressed by neurons during remission. This is the first study demonstrating the kinetics of the in vivo expression of costimulatory molecules, their ligands, and cytokines in an autoimmune disease model characterized by remissions and relapses. Our data suggest that the targeting of costimulatory molecules to block an immune response must take into account the expression patterns in the target organ.

Linomide (roquinimex) affects the balance between pro- and anti-inflammatory cytokines in vitro in multiple sclerosis

OBJECTIVES

Multiple sclerosis (MS) is characterized by high levels of circulating mononuclear cells (MNC) that respond to myelin proteins like myelin basic protein (MBP) in vitro by expressing mRNA of both pro-inflammatory cytokines, e.g. interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha) and lymphotoxin (LT) that may make MS worse, and anti-inflammatory cytokines like IL-4, IL-10 and transforming growth factor-beta (TGF-beta) that may act beneficially. Substances that down-regulate cytokines such as TNF-alpha or promote IL-10 or TGF-beta can be anticipated to affect MS beneficially.

MATERIAL AND METHODS

In situ hybridization to detect and enumerate IFN-gamma, TNF-alpha, LT, IL-4, IL-10 and TGF-beta mRNA expressing blood MNC after stimulation with myelin basic protein (MBP), control antigens and without antigen in presence and absence of Linomide (roquinimex, LS-2616) was employed. In parallel, ELISPOT assay to detect MBP- and PHA-reactive IFN-gamma secreting blood MNC+/-Linomide was used.

RESULTS

Here we report that Linomide, a synthetic immunomodulator, at concentrations effective in vivo reduces the number of MBP-reactive TNF-alpha and increases MBP-reactive IL-10 and TGF-beta mRNA expressing MNC from MS patients' blood when analysed in vitro. Compared to dexamethasone, Linomide up-regulated levels of blood MNC expressing mRNA of TGF-beta after culture in presence of MBP.

CONCLUSIONS

Changes of cytokine balance towards a production of anti-inflammatory cytokines could be a desirable effect to be evaluated in future drug studies of Linomide-like substances. At present, Linomide is not evaluable in MS clinical trials due to side-effects.

The phosphodiesterase i.v. inhibitor rolipram in vitro reduces the numbers of MBP-reactive IFN-gamma and TNF-alpha mRNA expressing blood mononuclear cells in patients with multiple sclerosis

The inflammatory nature of multiple sclerosis (MS) implicates the participation of cytokines as immune response mediators. Targeting the cytokine balance by downregulating proinflammatory cytokines and/or upregulating immunosuppressive cytokines could benefit patients with MS. This article reports on the in vitro effects of the phosphodiesterase i.v. inhibitor Rolipram on the production of pro- and anti-inflammatory cytokines in MS and, for reference, in myasthenia gravis (MG). Blood mononuclear cells (MNC) were cultured in the presence of the organ-specific autoantigens myelin basic protein (MBP) or acetylcholine receptor (AChR), and in the absence of antigens, with and without Rolipram. In situ hybridization with synthetic oligonucleotide probes was used to detect and enumerate blood MNC expressing IFN-gamma, TNF-alpha, LT, TGF-beta, IL-4, and IL-10 mRNA. Numbers of MNC-secreting IFN-gamma and IL-4 in blood blood were examined by ELISPOT assays. Rolipram reduced the numbers of MBP-reactive IFN-gamma- and TNF-alpha mRNA-expressing blood MNC in MS, and numbers of AChR-reactive IFN-gamma-, TNF-alpha-, and LT mRNA-positive cells in MG. In contrast, expression of the Th2 cell related IL-4 and the anti-inflammatory IL-10, and TGF-beta was not affected. These data support a role for Rolipram in the treatment of diseases such as MS.

Interleukin-12 and perforin mRNA expression is augmented in blood mononuclear cells in multiple sclerosis

Cytokines are suggested to orchestrate an abnormal immune response in multiple sclerosis (MS). The regulatory cytokine interleukin (IL)-12 induces T-helper (Th) cell switch to the Th1 type and the production by cytotoxic T cells of perforin, a cell lysis-inducing factor. It has been suggested that Th1-like cytokines may promote the development of MS, and the production of perforin to induce oligodendrocyte damage. In-situ hybridization with radiolabelled synthetic oligonucleotide probes was used to detect and enumerate mononuclear cells (MNC) expressing IL-12 and perforin mRNA in blood and cerebrospinal fluid (CSF) from patients with MS and controls. Plasma and CSF levels of IL-12 (p70) were evaluated by ELISA. Higher numbers of IL-12 and perforin mRNA-expressing MNC were registered in blood in MS and also in controls with aseptic meningoencephalitis (AM) compared to healthy subjects. There were a few patients with other non-inflammatory neurological diseases who also had high levels of IL-12 or perforin mRNA expressing blood MNC. A parallel elevation was observed for IL-12 (p70) concentrations in plasma. In the MS patients' CSF, there was a further augmentation of IL-12 mRNA expressing MNC. To evaluate autoantigen-induced IL-12 and perforin mRNA expression, blood MNC were cultivated +/- myelin basic protein (MBP), a candidate autoantigen in MS. Higher numbers of MBP-reactive IL-12 and perforin mRNA expressing blood MNC were detected in MS than controls. The augmentation of both IL-12 and perforin in MS might reflect ongoing inflammatory processes in MS and could represent targets for future treatments.

Influence of IFN-beta1b (Betaferon) on cytokine mRNA profiles in blood mononuclear cells and plasma levels of soluble VCAM-1 in multiple sclerosis

Inflammatory cell infiltration within the central nervous system (CNS) and upregulation of both pro- and anti-inflammatory cytokines are characteristic for multiple sclerosis (MS). Treatment with interferon-beta 1b (IFN-beta1b) reduces the number and severity of MS relapses. To examine whether treatment with IFN-beta1b affects levels of cytokine mRNA expressing blood mononuclear cells (MNC) we employed in-situ hybridization with synthetic oligonucleotide probes to detect and enumerate IFN-gamma, TNF-alpha, IL-10, TGF-beta and perforin mRNA expressing cells in MS patients before treatment with IFN-beta1b and during treatment for 3-6 weeks and for 3-6 months. Numbers of blood MNC spontaneously expressing TNF-alpha and IL-10 mRNA were lower after 3-6 months of treatment, while numbers of IFN-gamma, TGF-beta and perforin mRNA expressing MNC were not affected by treatment. IFN-beta1b had no influence on levels of MBP-reactive IFN-gamma, TNF-alpha, TGF-beta, IL-10 or perforin mRNA expressing blood MNC determined after 3-6 weeks or 3-6 months of treatment. Parallel measurements of plasma concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1) revealed elevated levels after 3-6 weeks of treatment and these levels remained higher after 3-6 months of treatment. The results suggest that IFN-beta1b treatment upregulates plasma levels of sVCAM-1, but has little effects on numbers of blood MNC expressing mRNA of the pro- and anti-inflammatory cytokines under study.Copyright Lippincott-Raven Publishers

Cytokines and the pathogenesis of myasthenia gravis

Myasthenia gravis (MG) and its animal model experimental autoimmune myasthenia gravis (EAMG) are caused by autoantibodies against nicotinic acetylcholine receptor (AChR) in skeletal muscle. The production of anti-AChR antibodies is mediated by cytokines produced by CD4+ and CD8+ T helper (Th) cells. Emerging investigations of the roles of cytokines in MG and EAMG have revealed that the Th2 cell related cytokine interleukin 4 (IL-4), an efficient growth promoter for B-cell proliferation and differentiation, is important for anti-AChR antibody production. IL-6 and IL-10 have similar effects. The Th1 cytokine IFN-gamma is important in inducing B-cell maturation and in helping anti-AChR antibody production and, thereby, for induction of clinical signs and symptoms. Results from studies of time kinetics of cytokines imply that IFN-gamma is more agile at the onset of EAMG, probably being one of the initiating factors in the induction of the disease, and IL-4 may be mainly responsible for disease progression and persistance. Even though other Th1 cytokines like IL-2, tumor necrosis factor alpha (TNF-alpha), and TNF-beta as well as the cytolytic compound perforin do not directly play a role in T-cell-mediated help for anti-AChR antibody production, they are actually involved in the development of both EAMG and MG, probably by acting in concert with other cytokines within the cytokine network. In contrast, transforming growth factor beta (TGF-beta) exerts immunosuppressive effects which include the down-regulation of both Th1 and Th2 cytokines in MG as well as EAMG. Suppressive effects are also exerted by interferon alpha (IFN-alpha). Based on elucidation of the role of cytokines in EAMG and MG, treatments that up-modulate TGF-beta or IFN-alpha and/or suppress cytokines that help B-cell proliferation could be useful to improve the clinical outcome.

Soluble CD30 levels in plasma and cerebrospinal fluid in multiple sclerosis, HIV infection and other nervous system diseases

The CD30 molecule, a member of tumor necrosis factor superfamily, has been suggested to be preferentially expressed and released in soluble form by activated T cells that produce T helper 2 type (Th2) cytokines. To evaluate whether determination of soluble CD30 (sCD30) levels could have a diagnostic value in diseases associated with Th1 and Th2 cytokine involvement, we investigated sCD30 in plasma and cerebrospinal fluid (CSF) from patients with multiple sclerosis (MS), HIV infection and other nervous system diseases. There was no statistically significant difference for plasma sCD30 levels in these clinical groups. However, patients with HIV infection had higher levels of sCD30 in CSF than MS patients. The mean sCD30 values were 3 to 6 folds higher in plasma than in CSF in all patient groups. No relationships were found between sCD30 levels and different clinical variables of MS and HIV infection, except that higher plasma sCD30 levels in HIV-infected patients were found in those with higher CD4+ T cell counts (> 200 x 10(6)) compared to the group with lower cell counts. The findings indicate that determinations of plasma and CSF sCD30 levels in MS and HIV infection have limited or no value as diagnostic or prognostic indicator.

Tumor necrosis factor-alpha, lymphotoxin, interleukin (IL)-6, IL-10, IL-12 and perforin mRNA expression in mononuclear cells in response to acetylcholine receptor is augmented in myasthenia gravis

Myasthenia gravis (MG) is a neuromuscular disorder mediated by autoantibodies against the nicotinic acetylcholine receptor (AChR) on the postsynaptic membrane of the neuromuscular junction. The production of antibodies is regulated by T cells by means of immunoregulatory cytokines. To investigate the involvement of TNF-alpha, lymphotoxin (LT), IL-6, IL-10, IL-12 and perforin in MG, numbers of cytokine mRNA expressing blood mononuclear cells (MNC) were examined in patients with MG and controls. LT belongs to the Th1 cell related cytokines, IL-6 and IL-10 to the Th2 type, TNF-alpha is produced by both Th1 and Th2 cells, IL-12 induces T cell switch towards the Th1 type and perforin is an effector molecule inducing cell lysis. Short term culture of MNC with AChR revealed augmented levels of AChR-reactive TNF-alpha, LT, IL-6, IL-10, IL-12 and perforin mRNA expressing cells in MG compared to levels obtained without AChR or in presence of control antigen. AChR-reactive TNF-alpha, IL-6, IL-10, IL-12 and perforin mRNA expressing cells were higher in MG than controls. These findings suggest that the cytokines TNF-alpha, LT, IL-6, IL-10 and IL-12, and the cytolytic effector molecule perforin are also involved in MG.

Review: cytokines and the pathogenesis of multiple sclerosis

Perivascular accumulation of mononuclear cells (MNCs) in the central nervous system (CNS) and high levels of myelin autoantigen-reactive T cells in blood and further enriched in cerebrospinal fluid (CSF) are characteristic for multiple sclerosis (MS) and suggest a role for immunoregulatory cytokines in MS pathogenesis. The difficulties inherent to measurements of cytokine concentrations in body fluids have been partly overcome by adopting techniques allowing cytokine determinations on cellular level. MS is associated with the parallel up-regulation of proinflammatory [interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), lymphotoxin-alpha, and interleukin (IL)-12] and immune response-down-regulating [transforming growth factor-beta (TGF-beta), IL-10] cytokines systemically. A preferential up-modulation of TNF-alpha and lymphotoxin-alpha is observed in clinical exacerbations and of TGF-beta and IL-10 in remissions. The B cell-stimulating IL-4 and IL-6 are also up-regulated in MS, as is the cytolysis-promoting perforin. Cytokine production is elevated to an even higher degree in the CSF than systemically, underlining the autonomy of the immune responses in the CSF. All cytokine abnormalities are demonstrable already in very early MS, manifested by acute unilateral optic neuritis associated with more than two MS-like lesions on brain magnetic resonance imaging and oligoclonal IgG bands in CSF. The cytokine abnormalities hitherto observed are not MS specific, because they can be found in other inflammatory CNS diseases, e.g., aseptic meningitis and even noninflammatory neurological diseases like stroke. The influence on cytokine profiles, e.g., suppressing proinflammatory cytokines and promoting TGF-beta and IL-10, could be an important way to identify new and promising treatments of MS.

Multiple sclerosis: the proinflammatory cytokines lymphotoxin-alpha and tumour necrosis factor-alpha are upregulated in cerebrospinal fluid mononuclear cells

Lymphotoxin-alpha (LT-alpha) and tumour necrosis factor-alpha (TNF-alpha) promote inflammation in autoimmune diseases and have been detected in the multiple sclerosis (MS) brain lesions and blood, suggesting these cytokines are also present in the cerebrospinal fluid (CSF). To study this, mononuclear cells (MNC) were examined for transcripts of LT-alpha and TNF-alpha, using in situ hybridization (ISH) with synthetic oligonucleotide probes. Most patients with MS had LT-alpha and TNF-alpha mRNA-expressing MNC in their CSF at mean frequencies of about 1/2800 cells for both cytokines. Numbers were dramatically higher than in the paired blood specimens. Control patients with other inflammatory neurological diseases (OIND) also had LT-alpha and TNF-alpha mRNA-expressing cells in CSF but at mean frequencies of only 1/36,000 and 1/18,000 cells, respectively. In blood, levels were similar in OIND and MS. To elucidate the influence of myelin antigen stimulation on LT-alpha and TNF-alpha expression, MNC were cultivated with or without myelin basic protein. Strongly elevated levels of MBP-reactive TNF-alpha mRNA-expressing cells were detected in the MS patients' CSF, in particular when examined during clinical exacerbations, as well as MBP-reactive LT-alpha mRNA-expressing MNC. No such patterns were observed in the OIND controls. The strong accumulation of LT-alpha- and TNF-alpha-producing cells and of MBP-reactive LT-alpha and TNF-alpha mRNA-positive cells in the immediate vicinity of the demyelinating process in MS patients implicates a role of these cytokines in the development of MS.

Augmented expression of tumour necrosis factor-alpha and lymphotoxin in mononuclear cells in multiple sclerosis and optic neuritis

The involvement of proinflammatory cytokines tumour necrosis factor-alpha (TNF-alpha) and lymphotoxin (LT) in multiple sclerosis is suggested by the parallel occurrence of these proinflammatory cytokines in acute and chronic active multiple sclerosis brain lesions. We describe the use of in situ hybridization with radiolabelled cDNA oligonucleotide probes to detect and enumerate TNF-alpha and LT mRNA expressing mononuclear cells without culture, and after culture in the presence of myelin basic protein (MBP), control antigens or without antigen. Compared with patients with aseptic meningo-encephalitis, non-inflammatory neurological diseases and healthy controls, the multiple sclerosis patients had elevated numbers of TNF-alpha and LT mRNA expressing mononuclear cells in blood when enumerated without previous culture, and also after culture with MBP. The MBP-induced upregulation of TNF-alpha and LT was major histocompatibility complex (MHC) class II molecule dependent. Tumour necrosis factor-alpha mRNA expressing mononuclear cells were further enriched in the multiple sclerosis patients' CSF. Positive correlations were observed in multiple sclerosis between TNF-alpha and LT mRNA expressing blood mononuclear cells, MBP-reactive TNF-alpha and LT mRNA expressing cells, and TNF-alpha and interferon-gamma (INF-gamma) mRNA expressing mononuclear cells. Upregulation of TNF-alpha correlated positively with exacerbation, enhanced disability and the secondary progressive phase of multiple sclerosis. Patients with optic neuritis, in many instances representing very early multiple sclerosis, had TNF-alpha and LT positive blood mononuclear cells that were elevated to the same extent as patients with clinically definite multiple sclerosis. The findings support the hypothesis that TNF-alpha and LT play a harmful role in the development of multiple sclerosis and suggest that TNF-alpha could be useful as a disease activity marker in multiple sclerosis.

Increased interleukin-6 mRNA expression in blood and cerebrospinal fluid mononuclear cells in multiple sclerosis

The increased intrathecal production of immunoglobulins within the cerebrospinal fluid (CSF) compartment commonly observed in multiple sclerosis (MS) implicates participation of B cell activating factors. One effect of the cytokine interleukin (IL)-6 is induction of immunoglobulin production by activated B cells. Employing in situ hybridization (ISH) with synthetic oligonucleotide probes, we measured numbers of IL-6 mRNA-expressing mononuclear cells (MNC) in blood and CSF from patients with MS, aseptic meningo-encephalitis (AM), and in blood from patients with other neurological diseases (OND) and healthy subjects. Numbers of IL-6 mRNA-expressing MNC were elevated in blood (mean frequency 1 per 33,000 MNC) and even further enriched in the CSF (1 per 10,000 MNC) of MS patients, and to a similar extent in AM patients' blood. Cultivation in the presence of myelin basic protein and proteolipid protein revealed strong augmentation of IL-6 mRNA-positive cells in MS but not in OND. The results suggest that IL-6 is one of several cytokines which are upregulated in MS, in particular locally in the CSF. A role of IL-6 in MS, whether disease- promoting or protective, remains unclear.

Tumor necrosis factor alpha-308 alleles in multiple sclerosis and optic neuritis

Tumor necrosis factor-alpha (TNF-alpha), a proinflammatory cytokine, is believed to play an important role in multiple sclerosis (MS) pathogenesis. A bi-allelic polymorphism in the TNF-alpha promoter region (TNF alpha-308), has been reported to influence levels of TNF-alpha production. In the present study, we investigated the TNF alpha-308 polymorphism in 93 patients with MS, 17 patients with optic neuritis (ON) and 95 healthy individuals using an allele-specific PCR technique. Allelic genotype was compared with TNF-alpha mRNA expression levels and HLA class II phenotypes. No significant difference regarding the TNF alpha-308 polymorphism was observed between MS patients and controls. Specifically, the less common allele, TNF2, which is associated with higher expression levels of TNF-alpha, was somewhat less frequent among MS patients. In fact, analysis of 19 patients homozygous for the MS associated HLA-DR-DQ haplotype HLA-Dw2 showed that this haplotype does not carry the TNF2 allele. In addition, in 47 patients, the TNF-alpha alleles did not correlate with expression levels measured as numbers of TNF-alpha expressing cells. Thus, we found no evidence for an important role of TNF alpha-308 polymorphism for genetic susceptibility to MS.

Expression of IFN-gamma, IL-4, and TGF-beta in multiple sclerosis in relation to HLA-Dw2 phenotype and stage of disease

Multiple sclerosis (MS) is associated with upregulation of both proinflammatory (interferon-gamma, IFN-gamma) and immunosuppressive (transforming growth factor-beta, TGF-beta) cytokines. To examine a possible relation between the MS-related HLA haplotype Dw2 and cytokine profiles, we used in situ hybridization with labeled cDNA oligonucleotide probes to detect transcripts of the T helper type 1 (Th 1) cell related IFN-gamma, the Th2 cell related interleukin-4 (IL-4) and of TGF-beta in blood and cerebrospinal fluid (CSF) mononuclear cells from 62 patients with MS. Compared to patients with other neurological diseases and healthy controls, MS patients had elevated numbers of IFN-gamma, IL-4 and TGF-beta mRNA expressing cells in blood and further augmented in CSF. Although several HLA-Dw2-positive individuals showed very high numbers of cells expressing these cytokines, no significant difference was found in comparison with Dw2-negative patients. However, expression of IL-4 and TGF beta mRNA was significantly increased in patients with shorter duration and minor disability and, for IL-4, in patients still in the relapsing-remitting phase compared to patients with secondary chronic progressive MS. Surprisingly, these changes which favour a beneficial, disease-downregulating effect of IL-4 and TGF-beta in MS, were found to be confined to HLA-Dw2-positive patients. Our findings suggest that the HLA phenotype does not influence the overall level of immune reactivity in MS, but may distinguish subgroups characterized by particular cytokine expression patterns.

Increased mRNA expression of IL-6, IL-10, TNF-alpha, and perforin in blood mononuclear cells in human HIV infection

Evidence has been presented for the involvement of various cytokines, including interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-alpha, in the pathogenesis of human immunodeficiency virus (HIV) infection. Since measured plasma levels may poorly reflect in vivo production of cytokines, we adopted in situ hybridization with cDNA oligonucleotide probes to enumerate blood mononuclear cells (MNCs) expressing mRNA for IL-6, IL-10, TNF-alpha, and perforin. The HIV-infected patients had elevated levels of MNCs expressing mRNA for all four cytokines compared to healthy controls. Numbers of IL-6 mRNA-expressing cells were higher in patients with clinical AIDS than in asymptomatic seropositive patients, and correlated inversely with CD4+ cell counts in blood, reflecting the involvement of IL-6 in later stages of HIV infection. The described approach could be an alternative way to study cytokines in HIV infection.

Cytokine mRNA profiles in mononuclear cells in acute aseptic meningoencephalitis

Cytokines are important modulators of inflammation and immune responses. Using in situ hybridization with radiolabelled cDNA oligonucleotide probes, we studied the expression of mRNA encoding the cytokines gamma interferon (IFN-gamma), interleukin 4 (IL-4), IL-6, IL-10, transforming growth factor beta (TGF-beta), tumor necrosis factor alpha (TNF-alpha), lymphotoxin, and perforin in mononuclear cells (MNC) from blood and cerebrospinal fluid (CSF) of patients with acute aseptic meningoencephalitis (AM) and from blood of healthy controls. Patients in the acute phase of AM had elevated numbers of IFN-gamma mRNA-expressing cells in the blood compared with that of controls and higher numbers of IFN-gamma mRNA-expressing cells in their CSF compared with that of convalescent-phase patients, which is in accordance with the antiviral effects of this cytokine. Upregulation of IL-4, IL-6, and IL-10 was found in convalescent-phase patients, which is consistent with the longstanding B-cell response found in AM. TGF-beta and perforin were upregulated in both stages of AM, while the numbers of blood and CSF MNC expressing cytokine mRNA of the TNF family (TNF-alpha and lymphotoxin) did not differ between patients with AM and controls. An even higher elevation in CSF was noticed for MNC expressing most of the cytokines, particularly IL-4 and TGF-beta, reflecting the autonomy of the immune response in the CSF. The definition of cytokine profiles in AM, a self-limiting and benign disease, provides a foundation for future comparisons with other infectious and inflammatory nervous system diseases.

Transforming growth factor-beta 1 suppresses autoantigen-induced expression of pro-inflammatory cytokines but not of interleukin-10 in multiple sclerosis and myasthenia gravis

Multiple sclerosis (MS) is associated with high levels of circulating T lymphocytes that respond to the myelin antigens myelin basic protein (MBP) and proteolipid protein (PLP) by producing various cytokines including interferon-gamma (IFN-gamma) that makes MS worse and transforming growth factor-beta (TGF-beta), an endogenously produced immunosuppressant that might act beneficially. To further define the role of TGF-beta in MS, we examined the effects of recombinant TGF-beta 1 (rTGF-beta 1) on autoantigen-mediated regulation of cytokines in MS and myasthenia gravis (MG). Blood mononuclear cells (MNC) were cultivated with or without rTGF-beta 1, and with or without autoantigen or the recall antigen PPD. MNC expressing cytokine mRNA were detected after in situ hybridization with radiolabeled cDNA oligonucleotide probes. Femtogram concentrations of rTGF-beta 1 suppressed MBP-, PLP- and PPD-induced upregulation of IFN-gamma, IL-4, IL-6, tumor necrosis factor-alpha (TNF-alpha), TNF-beta and perforin in MS, and acetylcholine receptor (AChR)-induced augmentation of these pro-inflammatory cytokines in MG, but had no effects on autoantigen- or PPD-induced expression of IL-10 or TGF-beta itself. rTGF-beta 1 also suppressed numbers of myelin antigen-reactive IFN-gamma- and IL-4-secreting cells in MS and AChR-reactive IFN-gamma and IL-4 secreting cells in MG. The selective suppressive effects of TGF-beta 1 on autoantigen-induced upregulation of pro-inflammatory cytokines makes TGF-beta 1 attractive as a treatment alternative in MS and MG.

Increased mRNA expression of IL-10 in mononuclear cells in multiple sclerosis and optic neuritis

The inflammatory nature of multiple sclerosis (MS) implicates the participation of immunoregulatory cytokines, including the Th2 related IL-10. We describe the use of in situ hybridization with cDNA oligonucleotide probes to detect and enumerate mononuclear cells (MNC) expressing mRNA for IL-10, which is known to down-regulate Th1 cell related cytokines such as interferon-gamma. Expression of IL-10 was studied in blood MNC of MS and blood and cerebrospinal fluid (CSF) MNC of optic neuritis (ON) patients without culture and after culture in the presence of myelin basic protein (MBP), the control antigen acetylcholine receptor (AChR), and without antigen. Numbers of IL-10 mRNA expressing MNC were elevated in the MS patients' blood both when enumerated without culture and after culture with MBP. Control patients with myasthenia gravis had elevated numbers of AChR-reactive IL-10 mRNA expressing cells, while numbers of MBP-reactive IL-10 positive cells did not differ from numbers registered in cells without antigen. Patients with ON, in many instances representing early MS, had IL-10 positive blood MNC that were elevated to the same extent as in clinically definite MS, and further increased in the CSF. ON patients examined within 1 month after onset had lower numbers of MBP induced IL-10 mRNA expressing blood MNC compared with patients examined later suggesting that IL-10 is related to the degree of inflammation and outcome in ON.

Augmented interferon-gamma, interleukin-4 and transforming growth factor-beta mRNA expression in blood mononuclear cells in myasthenia gravis

The abnormal T lymphocyte-dependent production of antibodies to the nicotinic acetylcholine receptor (AChR) in myasthenia gravis (MG) suggests a role for immunoregulatory cytokines. We examined the T helper type 1 (Th1) cell-associated interferon-gamma (IFN-gamma) that promotes cell-mediated immunity, the Th2 cell-related interleukin-4 (IL-4) that augments B cell immunity, and transforming growth factor-beta (TGF-beta) that downregulates immune responses but enhances isotype switching. Blood mononuclear cells (MNC) expressing cytokine mRNA were enumerated after in situ hybridization with labelled complementary DNA oligonucleotide probes for IFN-gamma, IL-4 and TGF-beta. MG patients had elevated numbers of cells expressing IFN-gamma and IL-4 compared to patients with non-inflammatory neurological diseases and healthy controls, implying that both Th1- and Th2-like cells are involved in MG. TGF-beta-positive cells were also elevated in MG. The levels of cytokine-positive MNC were similar in MG and in control patients with other inflammatory neurological diseases. There were no associations between numbers of cytokine-positive blood MNC and clinical variables of MG, but individual patients need to be studied over the course of MG to clarify a relation between the cytokines under study and clinical or laboratory variables of MG.

Increased levels of interferon-gamma (IFN-gamma), IL-4 and transforming growth factor-beta (TGF-beta) mRNA expressing blood mononuclear cells in human HIV infection

Evidence has been presented for the involvement of IFN-gamma, IL-4 and TGF-beta in AIDS. Measured plasma levels may, however, poorly reflect in vivo production, since cytokines act auto- and paracrinally and have very short half life in plasma. In situ hybridization with complementary DNA oligonucleotide probes was used to enumerate blood mononuclear cells expressing cytokine messenger RNA (mRNA). HIV-infected patients had elevated blood levels of cells expressing each of the cytokines, with predominance for cells expressing TGF-beta mRNA. All AIDS patients included had elevated numbers of IL-4 mRNA-expressing cells, and levels of cells expressing this cytokine correlated inversely with counts of CD4+ cells in blood, reflecting the involvement of Th2-like cells in later stages of HIV infection. The described approach should be useful in further studies of cytokines in HIV infection and other diseases.