Interferon-gamma secretion by in vivo activated cytotoxic T lymphocytes from the blood and cerebrospinal fluid during mumps meningitis

Functional studies of cerebrospinal fluid T lymphocytes during acute viral infections of the nervous system are rare. Recently, we had the opportunity to investigate the requirements for interferon-gamma (IFN-gamma) production of human in vivo activated (primary) cytotoxic T lymphocytes (CTL) generated during acute viral meningitis. Two HLA-B7-restricted, CD4-, CD8+ CTL clones from cerebrospinal fluid of one patient with mumps meningitis were studied. Although lytic activity was restricted by HLA-B7, the clones produced similar amounts of IFN-gamma when stimulated with HLA-matched and mismatched mumps virus-infected target cells. In addition, peripheral blood mononuclear cells of infected patients secreted significant amounts of IFN-gamma when incubated with autologous or allogeneic (HLA-A/B-mismatched) mumps virus-infected target cells. T cells capable of lytic activity and IFN-gamma secretion could only be isolated from venous blood during the initial phase of the infection. We suggest that the ability of human in vivo activated CTL to secrete INF-gamma early during the course of inflammation and in a HLA-unrestricted fashion is important for the elimination of viruses invading the central nervous system.     

Interferon-α and interferon-γ production capacity of idiopathic isolated optic neuritis patients

Interferon-α and interferon-γ production by idiopathic isolated optic neuritis (ON) patients was studied. The production capacity was compared with that in two control groups: patients with iritis and healthy control subjects. A sensitive and reliable interferon bioassay was applied for interferon level measurements.Statistically significant differences were not found between patients and control groups in either interferon-α production or interferon-γ production.     

Evaluation of interleukin 10 and interferon-α in the cerebrospinal fluid and serum of patients with multiple sclerosis

The activities of IL-10, a cytokine produced by TH2 cells, monocytes and B-cells, and IFN-α, a product of activated macrophages/monocytes, were investigated in the CSF and serum samples of 25 subjects with clinically definite multiple sclerosis (MS), of whom 14 were in the active and nine in the stable phase, and of 15 controls with other noninflammatory neurological diseases (OND). Elevated CSF IL-10 and IFN-α levels were found in MS patients in the stable phase with respect to patients in the active phase (p > 0.001), while no significant differences were observed in the mean serum levels between MS patients (both in the active and stable phase) and controls. Finally, a significant correlation was detected between IL-10 and IFN-α in the CSF of MS patients in remission. This study suggests that IL-10 may downregulate MS progression.     

Plasma and cerebrospinal fluid α-MSH levels in the rat after hypophysectomy and stimulation of pituitary α-MSH secretion

Immunoreactive α-MSH was measured in cerebrospinal fluid (CSF) and plasma of rats. While treatment with haloperidol increased α-MSH levels in the plasma concentration of α-MSH in the CSF showed little change. Hypophysectomy also had little effect on the concentration of α-MSH in the CSF despite the fall in plasma α-MSH levels. This lack of correlation between α-MSH levels in the CSF and plasma suggests that the systemic circulation does not deliver α-MSH to the CSF. The apparently normal levels of α-MSH in the hypothalamus after hypophysectomy suggests that this tissue is able to synthesize α-MSH and it is possible that the hypothalamus is a source of the α-MSH in the CSF.     

Lyme neuroborreliosis: cerebrospinal fluid contains myelin protein-reactive cells secreting interferon-γ

The mechanisms causing neurological manifestations and influencing the outcome in patients infected with the spirochete Borrelia burgdorferi are unknown. To study the involvement of autoimmune mechanisms in patients with Lyme neuroborreliosis (LN), ELIspot assays were used to determine the numbers of T lymphocytes which, upon stimulation with the myelin components myelin basic protein (MBP) and proteolipid protein (PLP) and two MBP peptides, responded by the secretion of interferon-γ (IFN-γ). LN patients had compared to patients with other neurological diseases and tension headache in CSF elevated numbers of MBP- and PLP-reactive T helper type 1 (Th1) like IFN-γ secreting cells at mean frequencies of about 1 per 1300 and 1 per 1500 CSF cells, respectively. Numbers were elevated up to 5 months after successful treatment of LN, and they did not correlate with clinical findings. Autoreactive T cells were not elevated in the LN patients' blood. These findings match the previously reported elevation of anti-MBP IgG antibody secreting cells exclusively in CSF in LN. The IFN-γ release by autoreactive cells and the secretion of autoantibodies in the CSF may have relevance for development and outcome of LN.     

Interferon-γ enhances the expression of retinal S-antigen, a specific neuronal cel marker

Interferon-γ (IFN-γ) is a potent lymphokine which can modify a variety of cellular processes. One of the mechanisms involved in these processes is the ability of IFN-γ to alter the regulation and expression of cellular proteins. Using analytical flow cytometry, we show that recombinant human IFN-γ can enhance the expression or retinal S-antigen in retinoblastoma cells. This enhancement was selective since two other retinal cell proteins, interphotoreceptor binding protein (IRBP) and photo-6, were not affected by IFN-γ treatment. Retinal S-antigen plays an important role in vision and is one of the retinal proteins capable of inducing an inflammatory eye disease called experimental autoimmune uveitis. These studies therefore demonstrate an important role for this lymphokine, that is, the enhanced expression of a neuronal cell protein. This finding may also identify additional mechanisms by which IFN-γ may participate in immunopathologic events in nervous tissue.     

Diagnostic value of atypical lymphocytes in cerebrospinal fluid from adults with enteroviral meningitis

We have noted two morphologically distinct types of atypical lymphocytes (AL) in the cerebrospinal fluid (CSF) of adult patients with meningitis: one, which we designate type-I AL, with multilobulated nuclei resembling those of the abnormal cells in adult T-cell leukaemia (ATL); and another, type-II AL, characterized by large lymphocytes with basophilic cytoplasm and nuclei containing coarse chromatin. Type-I AL were detected in 25 of 39 patients (64%) with enteroviral and in 11 of 109 (11%) with aseptic meningitis presumed to be caused by other viruses, but not in meningitis resulting from Cryptococcus neoformans (n = 14), Mycobacterium tuberculosis (n = 19) or acute bacterial infection (n = 49). Type-I AL were not seen in herpes zoster (n = 15) aseptic meningeal reactions (n = 15), or in leptomeningeal carcinomatosis (n = 14). Type-II AL were often present in meningitis of various aetiologies and in aseptic meningeal reactions, but not in leptomeningeal carcinomatosis. The presence of type-I AL in the CSF was found to be indicative of enteroviral meningitis with the highest predictive value (69%), while type-II AL had a lower diagnostic positive predictive value in meningitis of the five aetiologies above. Type-I AL immunostained for CD4, while type-II AL were stained for CD8. The presence of type-I AL in CSF strongly suggests enteroviral meningitis, which warrants careful follow-up without antifungal, antituberculous or antibacterial agents. However, type-I AL, which are likely to be virally transformed lymphocytes, must be distinguished from ATL cells, which frequently involve the meninges. Received: 29 May 1997 Received in revised: 1 November 1997 Accepted: 20 March 1998     

Interferon-α inhibits long-term potentiation and unmasks a long-term depression in the rat hippocampus

Interferons (IFN) appear to have various neuromodulatory actions. Here, we characterized the actions of IFN-α on the electrophysiological properties of CA1 hippocampal neurons using intracellular recordings. Superfusion of this cytokine did not alter the resting membrane potential, cell input resistance, action potentials, nor GABA-mediated fast synaptic potentials. IFN-α inhibited glutamate-mediated excitatory postsynaptic potentials (gEPSPs) and reversed or prevented long-term potentiation (LTP) induced by high-frequency tetanic stimulation. IFN-α reduced gEPSP amplitude far below its control value. Only a short-term potentiation (STP) was observed when either IFN-α or -2-amino-5-phosphonovalerato (APV; NMDA receptor antagonist) were present during tetanic stimulation. After this STP in presence of APV, IFN-α had no effect on gEPSPs. APV had no effect on LTP when applied after tetanic stimulation and did also not prevent IFN-α effect on LTP. Genistein (a tyrosine kinase inhibitor) or heat inactivation prevented IFN-α effects. IFN-α also decreased the depolarization induced by local application of glutamate but did not modify those induced by NMDA. Similarly, IFN-α reversed the potentiation (induced by tetanic stimulation) of glutamate-induced depolarizations. IFN-α did not affect long-term depression (LTD) induced by low-frequency tetanic stimulation. In conclusion, IFN-α-induced inhibition of LTP is, at least in part, mediated by a postsynaptic effect, by tyrosine kinase activity, and by non-NMDA glutamate receptors. Inhibition of LTP by IFN-α unmasks LTD which is induced by the same high-frequency tetanic stimulation.     

Reduction of cerebrospinal fluid amyloid β after systemic administration of M1 muscarinic agonists

Overproduction of the peptide amyloid β (Aβ) is a critical event in Alzheimer’s disease (AD). Systemic administration of 3 M1-selective muscarinic agonists, AF102B, AF150S and AF267B, decreased cerebrospinal fluid (CSF) Aβ concentrations; levels of CSF secreted β-APP were not significantly altered. Rabbits treated for 5 days with s.c. injections of each drug (2 mg/kg/day) had levels of CSF Aβ which were between 55 and 71% of control for Aβ 1–40 and between 59 and 84% of control for Aβ 1–42.     

Active and total T cells in blood and cerebrospinal fluid during the course of aseptic meningitis

Patients with aseptic meningitis (AM) were examined with the active T cell rosette test, which has been claimed to reflect cell-mediated immunocompetence more accurately than determination of total T cells. Higher percentages of active T cells were demonstrated in CSF compared to blood regardless if specimens were obtained on days 1–4, days 5–10, or later than 20 days after onset of symptoms. Active T cell percentages in CSF decreased when values for specimens obtained on days 5–10 were compared with those taken later than 20 days after onset, while no significant variations of active T cell percentages in blood were observed. The percentages of total T cells were higher in CSF than blood in specimens from days 5–10, and later than 20 days after onset, but no significant fluctuations of total T cells occurred in either CSF or blood over the course of AM.     

Virus-reactive and autoreactive T cells are accumulated in cerebrospinal fluid in multiple sclerosis

Elevated numbers of B cells--plasma cells secreting antibodies to measles and mumps virus, and to myelin associated glycoprotein (MAG), one of several putative myelin autoantigens--have previously been reported in cerebrospinal fluid (CSF) from patients with multiple sclerosis (MS), while it is unknown if corresponding T cell reactivities occur. We have defined the T cell reactivities to measles and mumps virus and to MAG in an immunospot assay which is based on the detection of secretion of interferon-gamma (IFN-gamma) by single cells upon stimulation with specific antigen in short term cultures. Patients with MS had higher numbers of MAG-reactive T cells in blood compared to controls, while no differences were observed for measles or mumps virus-reactive T cells. In CSF, elevated numbers of MAG-reactive T cells and also of measles- and mumps-reactive T cells were found in patients with MS compared to other neurological diseases. A strong accumulation of antigen-reactive T cells was observed in the MS patients' CSF compared to blood. The magnitude of these T cell reactivities did not correlate with clinical MS variables. The T cell repertoire in MS thus includes, besides myelin basic protein, proteolipid protein and myelin oligodendrocyte glycoprotein, also MAG and, in addition, measles and mumps virus. It is not clear whether these T cell reactivities accumulated in the CSF have importance for the pathogenesis of MS or reflect phenomena secondary to myelin damage, or result from both these alternatives.     

Determination of interferon-γ in the peripheral blood of multiple sclerosis patients in remission, using a chemiluminescence technique

The plasma from eight patients with multiple sclerosis (MS) whose disease was in remission, was investigated by a chemiluminescence technique for its ability to stimulate the oxidate metabolism of peripheral blood monocytes (PBM). The active fraction identified had a molecular weight between 13 700 and 43 000 Da. Its activity was reduced by incubation at pH 2, pH 4 or pH 6, or by treatment at 56°C for 1–3 h. The activity was also decreased, 58–100%, by prior incubation with antibodies to human interferon-γ (IFN-γ). We suggest that these results indicate that the increased chemiluminescence activity (CL-A) of PBM in MS patients in remission is due mainly to the presence of circulating IFN-γ.     

Treatment with Anti-interferon-γ Monoclonal Antibodies Modifies Experimental Autoimmune Encephalomyelitis in Interferon-γ Receptor Knockout Mice

The role of interferon-γ (IFN-γ) in the pathogenesis of multiple sclerosis and experimental autoimmune encephalomyelitis (EAE) is still controversial. We have studied the function of IFN-γ and its receptor in the EAE model using two different IFN-γ receptor knockout (IFN-γ R^−/−) mouse types: C57Bl/6×129Sv, with a disruption of the IFN-γ receptor cytoplasmic domain, and 129Sv, homozygous for a disrupted IFN-γ receptor gene. Mice were immunized with peptide 40-55 from rat myelin oligodendrocyte glycoprotein. A subgroup of mice was treated with anti-IFN-γ monoclonal antibodies (mAb) on day 8 postimmunization. Clinical scoring and both histological and immunohistochemical studies were undertaken for all groups. We hereby show that treatment with anti-IFN-γ mAb worsened the disease course of 129Sv wild-type mice. However, it decreased the mean daily score in IFN-γ R^−/− 129Sv and the incidence of the disease down to 50% in C57Bl/6×129Sv IFN-γ R^−/− mice. Moreover, after anti-IFN-γ mAb treatment, oxidative stress levels, metallothionein I and II antioxidant protein expression, and apoptoticneuronal death were increased in wild-type mice while decreased in IFN-γ R^−/− mice. These results suggest a putative alternative mechanism of action of this cytokine that works independent of its receptor.     

Lymphocyte subpopulations in cerebrospinal fluid and peripheral blood in multiple sclerosis

Lymphocytes subpopulations in cerebro-spinal fluid (CSF) and peripheral blood (PB) from multiple sclerosis (MS) patients were studied. PB of MS patients contains the same prevalence of E and EA rosette forming cells compared with controls, consisting of patients affected by various "nonimmunological" neuropsychiatric diseases. Cytochemical identification by the method of acid esterases in PB demonstrated in MS a prevalence of lymphocyte subpopulations similar to controls, and a relatively high percentage of macrophages compared with other methods, especially in MS patients: this may partially account for variable results obtained by various authors with the rosette technique. In CSF a significant decrease of total T, and particularly of T gamma cells, was found. Since T gamma lymphocytes have a suppressor effect on B cell proliferation and Ig synthesis, their decrease could be related with Ig hypersynthesis commonly found in the central nervous system of MS patients.     

Detection of tumor necrosis factor-α-positive cells in cerebrospinal fluid of patients with HTLV-I-associated myelopathy

Tumor necrosis factor (TNF)-α-positive cells constituted 1.6–18% and 8.2–23.5% of the total number of cerebrospinal fluid cells from six of 12 patients with HTLV-I-associated myelopathy and in all samples obtained from inflammatory cases, respectively. However, in non-inflammatory cases no TNF-α-positive cells were detected. These results suggest that some of the infiltrating CSF cells produce TNF-α, which plays a role in host immune defenses against causative agents including HTLV-I and in lesion formation within the central nervous system in inflammatory diseases.     

T and B lymphocytes in the cerebrospinal fluid of various neurological diseases

Summary Cerebrospinal fluids (CSF) from 66 patients with a variety of neurological disorders were studied for total protein content, absolute amount of albumin, IgA, IgG and IgM, as well as their quotients (fraction to total protein ratio), cell numbers and B cell and T cell levels. In addition, the percentage of B cells and T cells in the blood was determined in 34 patients and serum immunoglobulin levels were estimated in 51 patients. In noninflammatory diseases of the CNS, the percentage of B cells was slightly higher and T cell levels were lower in the CSF in comparison to corresponding blood values. The B cell to T cell ratio in viral meningitis was altered in the CSF. An apparent increase in the T cell level led to a decrease of B cell values. Similar changes were also found in optic neuritis. The percentage of T cells was higher in relapsing multiple sclerosis than in the chronic progressive form. There were less striking changes in the B cell to T cell ratios in the CSF of other inflammatory diseases of the CNS.

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Zusammenfassung Von 66 Patienten wurden im Liquor außer Zellzahl, den B-und T-Zellen noch der Gesamteiweißgehalt sowie die absoluten Werte von Albumin, IgA, IgG, IgM und deren relativer Anteil am Gesamteiweiß untersucht. Im Blut war die Bestimmung der B- und T-Zellen bei 34 Patienten, die der Immunglobuline bei 51 Patienten möglich. Bei nicht entzündlichen Erkrankungen des zentralen Nervensystems liegt der prozentuelle Anteil der T-Zellen im Liquor zumeist etwas niedriger, der der B-Zellen etwas höher als die entsprechenden Blutwerte. Bei viralen Miningitiden kommt es zu einer deutlichen Verschiebung dieses B:T-Zellen-Verhältnisses, und zwar zu einem Ansteigen der T-Zellen bei daraus resultierendem B-Zellen-Abfall. Ähnliche Relationsveränderungen sind bei retrobulbären Neuritiden, die als Erstsymptome einer MS auftreten, zu finden. MS-Fälle mit schubförmiger Verschlechterung weisen einen höheren Anteil an T-Zellen auf als MS-Fälle mit chronisch progredientem Verlauf. Eitrige Meningitiden, Myelitiden und Polyneuropathie-Syndrome zeigen die Tendenz des T-Zellen-Anstieges und B-Zellen-Abfalles im Liquor in geringerer Ausprägung.

     

Polymorphonuclear pleocytosis in the cerebrospinal fluid during chemotherapy for tuberculous meningitis

Summary Five patients on chemotherapy for tuberculous meningitis developed sudden and unexpected cerebrospinal fluid pleocytosis consisting predominantly of polymorphonuclear leucocytes. The cellular changes, which developed 4–108 days after starting treatment, were not accompanied by an alteration in the clinical state and disappeared within a week whether or not an additional antibiotic was prescribed. Though the cause is uncertain, possible mechanisms are discussed. We are prompted to report these cases because the cytological changes are not well recognised and may cause difficulties in management.     

脑脊液14-3-3蛋白检测对隐球菌性脑膜炎的意义

目的评价脑脊液酪氨酸3-加单氧酶/色氨酸5-加单氧酶激活蛋白(14-3-3蛋白)含量的变化与隐球菌性脑膜炎(CM)患者病情及预后之间的联系。方法从16例隐球菌性脑膜炎患者和18例对照组中获取脑脊液标本,进行脑脊液细胞学检测,并用ELISA法检测脑脊液中14-3-3蛋白含量。结果隐球菌性脑膜炎患者脑脊液中14-3-3蛋白含量较对照组增高,P<0.05。在隐球菌性脑膜炎患者中,有7例患者经过抗真菌治疗症状好转,脑脊液中的隐球菌被清除,但14-3-3蛋白并没有随着治疗的好转及隐球菌的清除有显著下降。结论隐球菌性脑膜炎患者脑脊液中14-3-3蛋白含量较对照组明显增高,且不会在短期内随着治疗的进行和临床症状的改善而显著下降。