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Dendritic cells (DC), as the most effective antigen presenting cells, are protagonists of the complex immune network involved in multiple sclerosis (MS) lesion formation. Glatiramer acetate (GA), a synthetic random copolymer, is thought to exert its therapeutical effect in MS by favouring both Th2 cell development and IL-10 production from peripheral lymphocytes as well as by systemically affecting the antigen presenting cells. In the present study we further analysed the mechanisms of action of GA by using an autologous DC-lymphocytes (Ly) coculture system from 11 MS patients and 12 matched healthy controls (HC). We found that, in MS patients, pretreatment with GA significantly decreases the in vitro proliferative effect of DC on lymphocytes as compared to HC and to unpulsed or myelin basic protein (MBP)-pulsed DC from MS patients ( P < 0·05). In addition, GA-treated DC from both MS patients and HC significantly increase the lymphocyte production of IL-5 and IL-13 as compared to MBP-treated DC ( P < 0·05). In conclusion our in vitro study may provide new therapeutical mechanisms of GA on lymphocytes, antiproliferative and Th2-favouring effects, which are mediated by monocyte-derived DC. [ABSTRACT FROM AUTHOR]

This study was designed to investigate the therapeutic effects of interferon (IFN)-γ-modulated dendritic cells (DC) in experimental autoimmune myasthenia gravis (EAMG). We induced EAMG in Lewis rats by immunization with Torpedo nicotinic acetylcholine receptor (nAChR) and adjuvant. On day 33 post-immunization (p.i.), splenic DC were prepared, exposed to IFN-γ alone (IFN-γ-DC) or to IFN-γ in combination with 1-methyl-DL-tryptophan (1-MT), the specific inhibitor of indoleamine 2,3-dioxygenase (IDO) (IFN-γ + 1-MT-DC), and injected subcutaneously into rats with incipient EAMG on day 5 p.i. A control group of EAMG rats received naive DC on day 5 p.i., while another group received 1-MT every other day, intraperitoneally (p.i.), from days 5 to 41 p.i. The severity of clinical signs of EAMG was reduced dramatically in IFN-γ-DC-treated rats compared to rats receiving naive DC, IFN-γ + 1-MT-DC or 1-MT alone. The number of plasma cells secreting nAChR antibodies was reduced and the expression of B cell activation factor (BAFF) on splenic and lymph node mononuclear cells (MNC) was down-regulated in rats treated with IFN-γ-DC.In vitroco-culture of MNC derived from EAMG rats with IFN-γ-DC produced relatively few cells secreting nAChR antibodies. Addition of 1-MT to the co-culture significantly increased the number of cells secreting nAChR antibodies. We conclude that IFN-γ-DC reduced the number of plasma cells secreting nAChR antibodies in an IDO-dependent manner and ameliorated the development of EAMG in Lewis rats. [ABSTRACT FROM AUTHOR]

Dendritic cells (DC) represent a phenotypically heterogeneous population endowed with two important biological functions, immunity and tolerance. Here we report that the injection of splenic CD8 α+ DC, derived from rats with experimental allergic encephalomyelitis (EAE), delayed the onset and suppressed the severity of EAE in Lewis rats. This was accompanied by the lack of magnetic resonance imaging (MRI) lesions in the brain and spinal cord and by reduced numbers of inflammatory cells within the central nervous system. Injection of CD8α+ DC inhibited T cell proliferation that may relate to increased interferon (IFN)- γ and nitric oxide production. Although CD8+CD28– suppressor T cells, apoptotic cells and co-stimulatory molecules were not altered, CD4+ T cells expressing interleukin (IL)-10 were augmented in rats receiving CD8 α+ DC compared to rats receiving total DC or medium. These results demonstrate that rat splenic CD8 α+ DC could provide a cellular basis for a novel, individualized immunotherapy using autologous DC as a complement to conventional therapy in diseases with an autoimmune background such as multiple sclerosis. [ABSTRACT FROM AUTHOR]

SUMMARY Myeloid and plasmacytoid dendritic cells (DC) are present in cerebrospinal fluid (CSF) in non-inflammatory neurological diseases (NIND) and elevated in clinically definite multiple sclerosis (MS) and in early MS – acute monosymptomatic optic neuritis (ON). Here, we show that expression of CCR5, a chemokine receptor for regulated on activation, normal T cell expressed and secreted (RANTES) and macrophage inflammatory protein (MIP)-1α/β, is elevated on blood myeloid (CD11c+ ) DC in MS and ON compared to non-inflammatory controls. In contrast, expression of CXCR4, a receptor for stromal cell-derived factor (SDF)-1α, is similar in all groups. Blood myeloid DC from MS patients respond chemotactically to RANTES and MIP-1β, which are expessed in MS lesions. In active MS and ON, expression of CCR5 by myeloid DC in blood correlates with numbers of these cells in CSF. Thus, elevation of CCR5 may contribute to recruitment of myeloid DC to CSF in MS and ON. Recruitment of plasmacytoid DC to CSF appears to be CCR5-independent. [ABSTRACT FROM AUTHOR]

Investigates the effect of myelin basic protein (MBP) peptide 68-86 and interleukin-4 on allergic encephalomyelitis (EAE). Prevention of EAE in Lewis rats; Decrease in the levels of antigen + cytokine; Improvement of interleukin-4 and -10 responses.

The up-regulated B cell responses detectable in cerebrospinal fluid (CSF) and the augmented myelin antigen-specific T cell responses observed in the CSF as well as systematically in patients with multiple sclerosis (MS) suggest the involvement of cytokines in disease development and perpetuation. Here we report on the parallel involvement of TNF-α, IL-6, IFN-γ and IL-10 in MS and controls, using enzyme-linked immunospot (ELISPOT) assays to detect and enumerate cytokine-secreting mononuclear cells (MNC) prepared from blood and, for IL-6 and IL-10, from CSF without in vitro stimulation. MS is associated with elevated levels of TNF-α-secreting blood MNC when compared with levels in groups of control patients with myasthenia gravis (MG) and other neurological diseases (OND) or healthy subjects. This elevation was confined to patients with untreated MS and not present in those examined during ongoing treatment with IFN-β. Untreated patients with MS had lower numbers of IL-10-secreting blood MNC compared with the three control groups. In patients undergoing treatment with IFN-β, numbers of IL-10-secreting cells were in the same range as in controls. Normalization of TNF-α from elevated, and of IL-10 from decreased levels could be one reason for the beneficial effects of IFN-β in MS, although it remains to be shown whether these changes reflect phenomena primarily involved in MS pathogenesis or secondary changes. In CSF, levels of IL-10-secreting cells were higher than in blood in both MS and OND, with no difference between these groups. Systemic aberrations of IL-6 and IFN-γ and of IL-6 in CSF in MS versus controls were only minor, irrespective of treatment with IFN-β. [ABSTRACT FROM AUTHOR]

Umbilical cord blood of newborns and peripheral blood of healthy adults were investigated by an immunospot assay for cells secreting IgG, IgA and IgM antibodies against myelin basic protein (MBP), proteolipid protein (PLP), myelin-associated glycoprotein (MAG) and myelin oligodendrocyte glycoprotein (MOG) which represent putative antigens for an autoimmune attack in multiple sclerosis (MS) and against acetylcholine receptor (AChR) which is considered an important autoantigen in myasthenia gravis. Cells secreting antibodies against one or more of these autoantigens were detected in 18 out of 24 newborns, and in eight out of 20 adults. Eight of the cord blood samples contained cells secreting antibodies of IgG, IgA and/or IgM isotypes to one antigen, five to two antigens, two to three antigens, two to four antigens, and one to five antigens. Most prominent were anti-MBP IgG antibody secreting cells which were detected in 13 newborns at a mean number of 1/20 000 cord blood cells, and in six adults at a mean number of 1/105 peripheral blood cells. Anti-AChR IgG antibody secreting cells were detected in four out of 12 newborns versus four out of 14 peripheral blood specimens, at mean values of 1/5 cells in both instances. Cells secreting autoantibodies of IgA and IgM isotypes were less frequent both in cord blood and peripheral blood. The occurrence of nervous tissue autoantibody secreting cells in newborns must be related to a possible primary role of such autoantibodies in MS and myasthenia gravis. [ABSTRACT FROM AUTHOR]

By two-colour flow cytometric analysis, we found increased numbers of B cells co-expressing the pan-T cell marker CD5 and the B cell marker CD19 in cerebrospinal fluid (CSF) of 21 patients with multiple sclerosis (MS), compared with 17 control subjects with muscular tension headache. Only one patient with MS, but nine controls lacked CD5+ B cells in CSP. This difference was not observed in peripheral blood. Numbers of CD5+ 19+ B cells were increased in CSF compared with blood in MS, but not in the controls. In both groups., CD5+19+ B cells were not restricted to small resting lymphocytes, but were also found among larger-sized lymphocytes. The relative density of CD5 molecules and of CD19 molecules was lower in CD5+ 19+ than in CD5- 19+ B cells and CD5+ 19+ T cells. CD5+ B cells arc assumed to be responsible for autoantibody production, and our results suggest a pathogenetic role of such cells, predominantly within the central nervous system, in MS. [ABSTRACT FROM AUTHOR]

The B cell response against measles and herpes simplex virus (HSV) was evaluated in cerebrospinal fluid (CSF) and peripheral blood from patients with multiple sclerosis (MS) and controls by enumeration of cells secreting anti-measles and anti-HSV antibodies of IgG, IgA and IgM isotypes. We used a nitrocellulose immunospot assay which enables parallel enumeration of numbers of cells secreting total IgG, IgA and IgM. Anti-measles IgG antibody-secreting cells were present in CSF from 21 of 24 MS patients (mean 24 cells/104 mononuclear cells), and against HSV in CSF from seven of eight patients (mean 23/104 cells). No antibody-secreting cells were detectable in the patients' blood. Ten MS patients examined were negative for cells in CSF and blood producing anti-measles antibodies of IgA and IgM isotypes. Anti-measles IgG antibody secreting cells were also found in CSF from four of 18 controls, and anti-HSV IgG antibody-secreting cells in six of' 13, especially in patients with subacute or chronic inflammatory nervous system diseases. Our results confirm that viral antibodies in MS are produced within CSF and that this B cell response is preferentially sequestered to this compartment. Whether this viral B cell response in MS reflects specific activation due to persistence of viral antigens or an epiphenomenon remains to be clarified. [ABSTRACT FROM AUTHOR]

HLA-DR expression on T lymphocytes in cerebrospinal fluid (CSF) from patients with multiple sclerosis (MS) and acute aseptic meningo-encephalitis (AM), and from blood only from healthy controls was examined by a new double-immunofluorescence labelling assay using species-specific second layers on prefixed cell samples. Thirteen of 16 patients with AM (81%) had an elevated percentage of DR positive T cells in CSF against only two of 20 patients with MS (10%). Our data indicate that AM, an acute infection of the central nervous system (CNS), is accompanied by accumulation in CSF of activated, DR positive T cells as a reflection of actively involved cellular immunity within the CNS, while this accumulation of DR positive T cells is not seen in MS, a chronic inflammatory CNS disease, despite some of the patients being examined during clinical exacerbations. [ABSTRACT FROM AUTHOR]

Neopterin levels in cerebrospinal fluid (CSF) and serum were measured with a sensitive radioimmunoassay in patients with multiple sclerosis (MS), aseptic meningo-encephalitis (AM), other mostly non-inflammatory neurological diseases, and controls with tension headache or psychoneurosis. Elevated levels of neopterin were found in CSF in most patients during acute phase of AM, and normalization after clinical recovery. The elevation in CSF was not reflected in serum. Only four of 24 MS patients--three of them examined during exacerbation--had slight elevation of neopterin in CSF and all had normal serum levels, Neopterin levels in CSF correlated with mononuclear cell count. The elevation of neopterin observed in CSF in inflammatory CNS diseases despite low cell numbers in CSF compared to blood might reflect a high activation level of cells locally in the CNS, Neopterin in CSF is a valuable marker of acute cellular immune response. [ABSTRACT FROM AUTHOR]

The protein A plaque assay was used to enumerate IgM, IgA and IgG producing cells per 20 × 103 lymphocytes in cerebrospinal fluid (CSF) and peripheral blood (PB) from 37 patients with multiple sclerosis (MS) and in PB from healthy controls. Fifty-seven percent of the MS patients displayed in CSF cells producing IgM. 70% IgA and 89% IgG. IgM or IgA producing cells predominated in CSF from 10 patients, IgG in 27. Immunoglobulin producing cells were often present when the corresponding CSF Ig index was normal, confirming that enumeration of Ig producing cells is a more sensitive variable of the intrathecal immune status. No Ig producing ceils were found in CSF from four patients with tension headache, indicating absence of intrathecal Ig synthesis in healthy individuals. The patients with MS had higher numbers of IgM. IgA and IgG producing cells in PB than healthy controls, confirming occurrence of an extrathecal B cell response in MS. Active and stable MS patients did not differ regarding Ig producing cells in CSF nor in PB, which speaks in favour of continuous immune activity within as well as outside the CNS independent of clinical symptoms. [ABSTRACT FROM AUTHOR]

Umbilical cord blood of neonates and peripheral blood of healthy adults were analysed by in situ hybridization for numbers of mononuclear cells (MNC) expressing the cytokines IFN-γ, TGF-β and IL-4 mRNA without culture and after culture in the presence of acetylcholine receptor (AChR), myelin basic protein (MBP) and peripheral myelin protein P2. These antigens were chosen since they represent autoantigens in putatively immune-mediated neurological diseases, The numbers of cells expressing cytokine mRNA after 72 h culture in the presence of AChR, MBP and P2 were higher in cord blood than in peripheral blood of healthy adults. IFN-γ, TGF-β and IL-4 were always elevated in parallel. In cord blood there was a pronounced reactivity to several of the tested antigens, while such broad reactivity was not found in peripheral blood of healthy adults. No differences in cytokine mRNA expression were found between cord blood and peripheral blood of adults when cells were analysed without culture. The results show a capacity of cord blood cells to react to several autoantigens by the up-regulation of cytokine mRNA expression. [ABSTRACT FROM AUTHOR]

Experimental allergic neuritis (EAN) serves as a useful model for inflammation in the peripheral nervous system. To study the potential role of important immunoregulatory and effector lytokines in EAN, we examined the expression of mRNA for interferon-gamma (IFN-γ), IL-4 and TGF-β by in situ hybridization in lymph node and splenic cells cultured with bovine peripheral nerve myelin (BPM). P2 and P0 during the course of EAN in Lewis rats. Levels of IFN-γ mRNA expressing mononuclear cells (MNC) from lymph nodes and spleens roughly correlated with clinical status, consistent with a disease-promoting role for IFN-γ. BPM, P0 and P2-reactive IFN-γ mRNA-expressing T cells appeared in lymph nodes and spleen before onset of the disease, whereas a significant TGF-β response to BPM, P2 and P0 was observed at lower levels than the IFN-γ response and at onset of recovery, consistent with a disease down-regulating role of TGF-β. IL-4 mRNA-expressing cells were found at levels similar to TGF-β mRNA-expressing cells, and with the latest peak of the three cytokines examined. This result suggests that IL-4 may also suppress IFN-γ expression at late recovery phase of EAN. [ABSTRACT FROM AUTHOR]

Evidence has been presented for the involvement of IFN-γ, IL-4 and TGF-β 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 lo 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-β 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. [ABSTRACT FROM AUTHOR]

The electrophoretic distribution of Kappa and Lambda light chain antigenic determinants were studied in cerebrospinal fluid (CSF) and serum from cases with abnormal immunoglobulin G patterns on agar gel electrophoresis of CSF. Electrophoretically homogeneous immunoglobulin fractions containing an excess of either Kappa or Lambda determinants were found in CSF but not in serums. The findings indicate the production of monoclonal immunoglobulins within the central nervous system in multiple sclerosis. [ABSTRACT FROM AUTHOR]

Abnormal kappa : lambda chain ratios were found in cerebrospinal fluid from some patients with multiple sclerosis, but not in a variety of other neurological disorders. The increase in ratio was a property of immunoglobulin G. [ABSTRACT FROM AUTHOR]