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1.
Mult Scler Relat Disord ; 59: 103554, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35180617

ABSTRACT

BACKGROUND: Vaccination against SARS CoV-2 results in excellent personal protection against a severe course of COVID19. In People with Multiple Sclerosis (PwMS) vaccination efficacy may be reduced by immunomodulatory medications. OBJECTIVE: To assess the vaccination induced cellular and humoral immune response in PwMS receiving disease modifying therapies. METHODS: In a monocentric observational study on PwMS and patients with Neuromyelitis optica we quantified the cellular and humoral immune responses to SARS CoV-2. RESULTS: PwMS receiving glatiramer acetate, Interferon-ß, Dimethylfumarate, Cladribine or Natalizumab had intact humoral and cellular immune responses following vaccination against SARS CoV-2. B-cell depleting therapies reduced B-cell responses but did not affect T cell responses. Sphingosin-1-Phospate (S1P) inhibitors strongly reduced humoral and cellular immune responses. There was a good agreement between the Interferon gamma release assay and the T-SPOT assay used to measure viral antigen induced T-cell responses. CONCLUSION: This study demonstrates that S1P inhibitors impair the cellular and humoral immune response in SARS CoV-2 vaccination, whereas patients receiving B-cell depleting therapies mount an intact cellular immune response. These data can support clinicians in counselling their PwMS and NMOSD patients during the COVID 19 pandemic.


Subject(s)
COVID-19 , Multiple Sclerosis , Antibodies, Viral , COVID-19/prevention & control , Humans , Immunity, Cellular , Immunity, Humoral , Multiple Sclerosis/drug therapy , Vaccination
2.
Poult Sci ; 98(4): 1559-1567, 2019 Apr 01.
Article in English | MEDLINE | ID: mdl-30496524

ABSTRACT

The present study shows the prevalence and severity of foot pad dermatitis (FPD) in turkeys reared in organic production systems assessed at slaughterhouses in Germany. The investigations of altogether 1,860 turkeys of the strains Kelly Broad Breasted Bronze (Kelly BBB; 540 toms, 540 hens) and British United Turkeys (B.U.T.) 6 and the Test Product 7 (TP 7; 780 hens) showed that 97.7% of the examined turkeys were diagnosed with different degrees of FPD. Only 4.6% of the toms and 1.3% of the hens had feet without lesions. Most frequent were necrotic lesions measuring up to 2 cm in diameter (64.3% of all turkeys). Extensive necrotic lesions of the foot pads (toms: 29.8%; hens: 12.4%) and necrosis of superficial scales (toms: 11.3%; hens: 7.6%) were less frequent. Plantar abscesses were rare findings (1.9%). In general, the feet of the Kelly BBB hens were more affected by foot pad lesions than those of the Kelly BBB toms. There were significant differences between the investigated flocks concerning the occurrence of foot pad lesions. The aim in rearing turkeys must be the reduction of FPD.


Subject(s)
Animal Husbandry , Dermatitis/veterinary , Foot Diseases/veterinary , Organic Agriculture , Poultry Diseases/epidemiology , Turkeys , Abattoirs , Animals , Dermatitis/epidemiology , Dermatitis/etiology , Female , Foot Diseases/epidemiology , Foot Diseases/etiology , Germany/epidemiology , Hoof and Claw , Male , Poultry Diseases/etiology , Prevalence
3.
Eur J Neurol ; 25(9): 1134-1139, 2018 09.
Article in English | MEDLINE | ID: mdl-29683546

ABSTRACT

BACKGROUND AND PURPOSE: The gold standard for detection of intrathecal immunoglobulin synthesis is the measurement of oligoclonal bands (OCB). In the diagnosis of multiple sclerosis, the kappa free light chains (KFLC) index has a similar sensitivity and specificity as OCB. This study investigated whether determination of the KFLC index could be used to predict the presence of OCB. METHODS: The KFLC index was determined prospectively from 295 paired serum and cerebrospinal fluid samples. KFLC were determined by nephelometry using the N Latex FLC kappa kit (Siemens Healthcare Diagnostics Products GmbH) on the BN Prospec analyzer (Siemens Healthcare Diagnostics Products GmbH) (cohort I). A cut-off value was determined using receiver operating characteristic analysis in relation to OCB positivity. These results were validated prospectively in 96 samples (cohort II) as well as retrospectively in samples of 46 patients known to be OCB positive (cohort III). We also compared the agreement of two commercially available nephelometric KFLC assays. RESULTS: In cohort I, a KFLC index of 3.61 yielded 100% sensitivity and 88% specificity. Prospective validation of this cut-off value in cohort II showed 92% sensitivity and 96% specificity. In cohort III, a sensitivity of 93% was achieved. Comparison of Siemens and Binding Site (Birmingham, UK) assays revealed good agreement (r2  = 0.86). CONCLUSIONS: The KFLC index with a cut-off value of 3.61 had high diagnostic accuracy to predict immunoglobulin G synthesis via OCB analysis. Determination of the KFLC index provided a quantitative parameter that could be used as an initial diagnostic step in inflammatory central nervous system disorders before measuring OCB.


Subject(s)
Immunoglobulin kappa-Chains/cerebrospinal fluid , Immunologic Factors/cerebrospinal fluid , Multiple Sclerosis/cerebrospinal fluid , Oligoclonal Bands/cerebrospinal fluid , Adult , Aged , Cohort Studies , Female , Humans , Immunoglobulin G/biosynthesis , Male , Middle Aged , Multiple Sclerosis/diagnosis , Multiple Sclerosis/immunology , Nephelometry and Turbidimetry , Predictive Value of Tests , Prospective Studies , ROC Curve , Reproducibility of Results , Sensitivity and Specificity
4.
Acta Neurol Scand ; 129(1): 1-12, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23848237

ABSTRACT

The treatment of ischemic stroke is one of the great challenges in modern neurology. The localization and the size of the infarct determine the long-term disability of stroke survivors. Recent observations have revealed that stroke also alters the function of the immune system and vice versa: At the site of the infarct, a local inflammatory response develops that enhances brain lesion development. In experimental stroke, proof-of-concept studies confirm that inhibition of this immune response reduces lesion volume and improves outcome. In the peripheral blood of stroke patients, though, lymphocytopenia and monocyte dysfunction develop. These changes reflect a clinically relevant impairment of bacterial defense mechanisms because they are associated with an enhanced risk to acquire post-stroke infections. Stress hormones have been identified as important mediators of stroke-induced immune suppression. The pharmacological inhibition of beta adrenergic receptors, but not the inhibition of steroids, is effective in reducing infection and improving clinical outcome in experimental stroke; catecholamine release therefore appears causally related to stroke-induced immune suppression. Strong evidence supports the hypothesis that these immune alterations impact the clinical course of stroke patients. Thus, the development of new therapeutic strategies targeted to alter the immunological consequences of stroke appears promising. However, to date, the beneficial effects seen in experimental stroke have not been successfully translated into a clinical trial. This brief review summarizes the current understanding of the immunological consequences of ischemic stroke. Finally, we propose a concept that links the peripheral immune suppression with the development of local inflammation.


Subject(s)
Brain Ischemia/immunology , Adaptive Immunity , Adrenal Cortex Hormones/blood , Animals , Antibody Specificity , Autoantibodies/biosynthesis , Autoantibodies/immunology , Autoantigens/immunology , Autoimmunity , Brain Ischemia/blood , Catecholamines/blood , Cell Movement , Cerebral Infarction/immunology , Cytokines/blood , Disease Susceptibility , Humans , Immunity, Innate , Inflammation , Lymphocyte Subsets/immunology , Membrane Proteins/immunology , Membrane Proteins/physiology , Mice , Microglia/immunology , Models, Immunological , Nerve Tissue Proteins/immunology , Neuroimmunomodulation
5.
Acta Neurol Scand ; 122(4): 237-43, 2010 Oct.
Article in English | MEDLINE | ID: mdl-19925529

ABSTRACT

OBJECTIVES: Mitoxantrone is a cytotoxic drug with immune modulatory properties used in the treatment of progressive forms of multiple sclerosis (MS). We explored the effect of mitoxantrone treatment in MS patients on cytokine patterns induced in peripheral blood mononuclear cells (PBMC) and T-cell subsets ex vivo. MATERIALS AND METHODS: Blood was obtained before mitoxantrone infusion and 6, 12 and 18 days thereafter. Proliferation and prototypic TH1-, TH17- and TH2-type cytokines were determined following in vitro stimulation of PBMC, CD4+ and CD8+ T cells. In addition, a patient cohort receiving its first mitoxantrone treatment was cross-sectionally compared with a cohort of patients with more than 1 year of treatment. RESULTS: Mitoxantrone treatment increased the ex vivo production of the TH2 cytokines interleukin-4 (IL-4; P < 0.05) and IL-5 (P < 0.001) in phytohemagglutinin-stimulated CD4+ T cells within 18 days of treatment. The cross-sectional study revealed that long-term treatment with mitoxantrone increased the inducibility of IL-4 and IL-5 secretion by PBMCs and CD4+ T cells even further. No significant changes were observed for interferon-γ, tumour necrosis factor-α, IL-17 and IL-10. Mitoxantrone did not alter the proliferative capacity of ex vivo-stimulated T cells. CONCLUSION: Mitoxantrone treatment in MS enhances the inducibility of TH2-type cytokines, which may contribute to its beneficial effects in MS.


Subject(s)
Cytokines/immunology , Mitoxantrone/therapeutic use , Multiple Sclerosis/drug therapy , Multiple Sclerosis/immunology , Th2 Cells/immunology , Adult , Aged , Cell Proliferation/drug effects , Cells, Cultured , Cross-Sectional Studies , Enzyme-Linked Immunosorbent Assay , Female , Humans , Male , Middle Aged , Mitoxantrone/immunology , Mitoxantrone/pharmacology , T-Lymphocyte Subsets/drug effects , T-Lymphocyte Subsets/immunology , Th2 Cells/drug effects , Treatment Outcome
6.
Plant Biol (Stuttg) ; 11(2): 204-12, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19228327

ABSTRACT

TTG1 (Transparent Testa Glabra 1), a WD-40 repeat protein, is involved in regulation of flavonoid/anthocyanin biosynthesis, seed coat (mucilage) development/pigmentation and trichome formation in leaves. Here, we characterized the TTG1 gene of Matthiola incana wild type (e locus), showing 85.3% similarity to TTG1 of A. thaliana on the nucleotide level and 96.2% on the protein level. A white-flowered and glabrous mutant, line 17, of M. incana exhibits one nucleotide change, leading to an amino acid substitution directly in the WD motif (W158R). Correspondingly, the DFR (dihydroflavonol 4-reductase) gene, in which the expression is known to be dependent on TTG1, is not expressed in Matthiola mutant lines 17 (and 19). Comparison of the GC content of the Matthiola TTG1 (54.1%) and Arabidopsis TTG1 (46.1%) genes revealed a strong difference, mostly obtained by neutral substitutions (C to T transitions). To examine whether this is an ecologically influenced trend, a fragment of TTG1 was characterized from another Matthiola species (M. tricuspidata) and from Malcolmia flexuosa subsp. naxensis from the eastern Mediterranean, near a beach with sandy and salty soils. Both Matthiola species have a higher GC content in the TTG1 gene than Arabidopsis and the closer-related Malcolmia, indicating that the GC content is rather an evolutionary than an ecological signal. A similar WD-40 repeat protein gene (containing no intron in the 3' untranslated region) with high similarity to the Arabidopsis TTG1-like (AtAN11) gene was found in Matthiola.


Subject(s)
Arabidopsis Proteins/genetics , Brassicaceae/genetics , Genes, Plant , Alcohol Oxidoreductases/genetics , Anthocyanins/biosynthesis , Base Composition , Base Sequence , Brassicaceae/metabolism , Flavonoids/biosynthesis , Gene Expression , Genes, Plant/genetics , Molecular Sequence Data , Plant Proteins/genetics , Point Mutation , Seeds
7.
Eur J Neurol ; 15(8): 822-6, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18549400

ABSTRACT

BACKGROUND AND PURPOSE: Interferon beta (IFNbeta) preparations have some effect on the progressive phase of multiple sclerosis (MS). This limited effect might be partially because of a certain number of IFNbeta non-responders. Myxovirus resistance protein A (MxA)--a marker of IFNbeta bioactivity--was correlated with the clinical response during an uncontrolled trial, investigating the safety of IFNbeta-1b in primary progressive (PPMS) patients. METHODS: Twenty PPMS were treated with IFNbeta-1b (s.c.) for 1 year. Blood samples were taken before and 1, 2, 3, 6, 9, 12, and 15 months after treatment initiation and MxA protein levels were measured. Patients were clinically evaluated by EDSS and the more sensitive Incapacity Status Scale (ISS) and stratified in a stable and a progressing group. RESULTS: Using ISS criteria, 11 patients remained stable and nine patients progressed during treatment. The mean area under the curve of log MxA levels during treatment were significantly higher in stable than in progressing patients (10.87 vs. 5.99; P = 0.002). CONCLUSION: A good biological response to IFNbeta might be associated with a better clinical effect of this drug and could be helpful in future clinical studies for early identification of treatment responders.


Subject(s)
Adjuvants, Immunologic/therapeutic use , Biomarkers/blood , GTP-Binding Proteins/blood , Interferon-beta/therapeutic use , Multiple Sclerosis, Chronic Progressive/drug therapy , Adolescent , Adult , Area Under Curve , Enzyme-Linked Immunosorbent Assay , Female , Humans , Interferon beta-1b , Male , Middle Aged , Multiple Sclerosis, Chronic Progressive/blood , Myxovirus Resistance Proteins
8.
Eur J Neurol ; 15(6): 634-6, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18474079

ABSTRACT

Neutrophils in cerebrospinal fluid (CSF) samples are commonly considered a pathological feature; however, there is little information on the frequency and significance of these cells in CSF samples without pleocytosis. Therefore, the frequency and possible clinical significance of neutrophils in CSF was investigated. In a retrospective study comprising 1556 consecutive CSF samples, cytologies and patient records were reviewed. Five hundred thirty-eight CSF samples without pleocytosis were identified. Neutrophils were detected in 35.5% of these samples. The presence of neutrophils was associated with sepsis (P < 0.01), recent epileptic seizure (P < 0.0001), and blood contamination (P < 0.01). Amongst patients without CSF pleocytosis, CNS infections were not more frequent if neutrophils were present. Neutrophils are frequently observed in CSF with normal leukocyte counts. As sepsis but not CNS infection occurred more frequently in these patients, we conclude that in the absence of CSF pleocytosis, neutrophils are not indicative of CNS infections.


Subject(s)
Cerebrospinal Fluid/cytology , Leukocytosis/cerebrospinal fluid , Neutrophils , Epilepsy/cerebrospinal fluid , Female , Humans , Male , Middle Aged , Retrospective Studies , Seizures/cerebrospinal fluid , Sepsis/cerebrospinal fluid
9.
Acta Neurol Scand ; 116(3): 164-8, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17714329

ABSTRACT

OBJECTIVES: Migration of inflammatory cells across the blood-brain barrier is a central event in the formation of multiple sclerosis (MS) lesions and is known to be enhanced in MS patients. This study investigates the migration of CD4+ and CD8+ T-cell subsets and the effects of interferon-beta1a (IFN-beta1a) treatment on migration and matrix metalloproteinase-9 (MMP-9) production of these T-cell subsets. MATERIALS AND METHODS: An ex vivo transwell system was established to compare the migratory behaviour of lymphocytes isolated from normal controls and untreated MS patients. In addition, MS patients were investigated longitudinally after initiation of IFN-beta1a treatment. RESULTS: Migration of CD4+ T cells (P < 0.05), but not of CD8+ T cells, was enhanced in untreated MS patients compared with controls and was normalized by treatment with IFN-beta1a. In addition, IFN-beta1a treatment reduced MMP-9 production of CD4+ but not CD8+ T cells. CONCLUSION: Our results indicate that CD4+ T cells, but not CD8+ T cells, contribute to the enhanced ex vivo migration observed in MS.


Subject(s)
CD4-Positive T-Lymphocytes/physiology , CD8-Positive T-Lymphocytes/physiology , Cell Movement/physiology , Multiple Sclerosis, Relapsing-Remitting/pathology , Adjuvants, Immunologic/therapeutic use , Adult , Case-Control Studies , Female , Humans , Interferon beta-1a , Interferon-beta/therapeutic use , Longitudinal Studies , Male , Matrix Metalloproteinase 9/metabolism , Multiple Sclerosis, Relapsing-Remitting/drug therapy , Multiple Sclerosis, Relapsing-Remitting/enzymology
10.
Acta Neurol Scand ; 114(6): 368-73, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17083335

ABSTRACT

OBJECTIVES: It is unknown whether the immunological effects of beta-interferon (IFN-beta) differ in primary progressive multiple sclerosis (PPMS) when compared with relapsing-remitting multiple sclerosis (RRMS). Therefore, we investigated the effects of IFN-beta1b treatment in PPMS on proliferation and cytokine pattern of peripheral blood mononuclear cells (PBMC) and interleukin-10 (IL-10) serum level. METHODS: Eighteen patients were treated with IFN-beta1b for 12 months in an open-label trial. Serum and PBMC were collected longitudinally. RESULTS: Interleukin-10 serum levels increased (P = 0.02) during treatment. Tumor necrosis factor-alpha was increased in anti CD3 (OKT3) antibody stimulated PBMC during treatment (P = 0.04), whereas secretion of IL-10 was decreased in OKT3 (P = 0.04), but increased in concavalin A stimulated PBMC (P = 0.02). CONCLUSIONS: Interleukin-10 serum levels rose in IFN-beta1b-treated patients as has been observed in RRMS. The changes in cytokine patterns secreted by T-lymphocytes of PPMS patients, however, differ from effects observed in RRMS supporting the hypothesis that PPMS differs in some immunological aspects from RRMS.


Subject(s)
Adjuvants, Immunologic/pharmacology , Cell Proliferation/drug effects , Interferon-beta/pharmacology , Interleukin-10/blood , Leukocytes, Mononuclear/drug effects , Multiple Sclerosis, Chronic Progressive/blood , Adjuvants, Immunologic/therapeutic use , Adolescent , Adult , Cell Culture Techniques , Cytokines/metabolism , Female , Humans , Interferon beta-1b , Interferon-beta/therapeutic use , Leukocytes, Mononuclear/physiology , Male , Middle Aged , Multiple Sclerosis, Chronic Progressive/drug therapy
11.
Acta Neurol Scand ; 110(6): 386-92, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15527451

ABSTRACT

Endothelial activation is a key feature of multiple sclerosis (MS) pathogenesis. It is modulated by interferon beta-1b (IFNB-1b) treatment in relapsing-remitting MS (RRMS) patients. This particular pharmacodynamic effect still has to be proven in primary progressive MS (PPMS). In the current study, serum concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1) and sE-selectin were analyzed longitudinally in 18 PPMS patients before, during and after 12 months of treatment with IFNB-1b. During drug therapy there was a significant early and sustained increase of sVCAM-1 (overall P < 0.0001). Flu-like symptoms induced by IFNB-1b and also concomitant infections were associated with higher sVCAM-1 levels. Neutralizing antibodies to IFNB-1b were associated with lower sVCAM-1 levels. In conclusion, IFNB-1b modulates the adhesion cascade in patients with PPMS in a similar way it does in RRMS. Nevertheless, a clinical effect of IFNB in PPMS still has to be proven in a randomized controlled clinical trial.


Subject(s)
Adjuvants, Immunologic/pharmacology , Interferon-beta/immunology , Interferon-beta/pharmacology , Multiple Sclerosis/drug therapy , Multiple Sclerosis/immunology , Vascular Cell Adhesion Molecule-1/blood , Adjuvants, Immunologic/adverse effects , Adolescent , Adult , Cell Adhesion/drug effects , Endothelial Cells/physiology , Female , Humans , Interferon beta-1b , Interferon-beta/adverse effects , Male , Middle Aged
12.
J Neuroimmunol ; 133(1-2): 193-7, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12446022

ABSTRACT

The soluble form of the CD14 molecule (sCD14), a macrophage activity marker, was measured in the plasma of 17 patients with primary progressive multiple sclerosis (PPMS) and 20 patients with relapsing remitting MS (RRMS). In patients with PPMS, sCD14 levels were determined before and after treatment with interferon beta (IFNB). In both PPMS and in RRMS, sCD14 levels were significantly elevated compared to healthy controls. In patients with PPMS, sCD14 levels increased significantly during the first 3 months of IFNB therapy, then slightly decreased, but still remained elevated compared with levels before therapy. Therefore, the elevated sCD14 levels may be a marker in evaluating biological response to IFNB therapy.


Subject(s)
Central Nervous System/immunology , Interferon-beta/therapeutic use , Lipopolysaccharide Receptors/immunology , Macrophage Activation/immunology , Macrophages/immunology , Multiple Sclerosis/blood , Multiple Sclerosis/immunology , Up-Regulation/immunology , Adult , Age Factors , Central Nervous System/drug effects , Central Nervous System/metabolism , Female , Humans , Interferon beta-1a , Interferon beta-1b , Lipopolysaccharide Receptors/drug effects , Macrophage Activation/drug effects , Macrophages/drug effects , Male , Middle Aged , Multiple Sclerosis/drug therapy , Predictive Value of Tests , Sex Factors , Treatment Outcome , Up-Regulation/drug effects
13.
Hematol J ; 3(4): 179-84, 2002.
Article in English | MEDLINE | ID: mdl-12189563

ABSTRACT

INTRODUCTION: Radiation therapy (RT) was the first treatment modality demonstrating cure of Hodgkin's disease. Long-term side-effects of this treatment, however, have become evident in the past few years. PATIENTS AND METHODS: By reviewing the results of megavoltage radiotherapy as initial treatment in a consecutive series of 106 patients with early-stage Hodgkin's disease (HD), survival, relapse-free interval, salvage rate of relapsing cases, and incidence of second tumours were evaluated. RESULTS: Subtotal node irradiation was given to all patients with supradiaphragmatic disease, except for 15 patients with limited stage IA-IIA, who received mantle field treatment only. Inverted Y field irradiation was given to all seven patients with subdiaphragmatic disease. The median age was 32 years (range 14-77). The median follow-up was 140 months. The relapse-free interval of the patient population was 78% at 5 years and 72% at 10 years. The overall survival (OS) was 90% and 79%, respectively. Salvage therapy was successful in 26 of 30 relapsing patients. Twelve recurrences were located inside the treatment field. Sixteen patients (15%) developed second malignancies: cancer of the lung (two), ovary (two), cervix (one), colon (two), breast (three), stomach (one), skin (two), hypopharynx (one), and non-Hodgkin lymphoma (two). Eleven of these were located within the radiation field. CONCLUSION: Although RT is intended to be a curative treatment, up to 30% recurrences occur. Mortality was not determined by primary HD, but by second malignancies, which are likely related to treatment. New treatment strategies, aiming at long-term freedom from relapse without carcinogenic side-effects, are urgently needed.


Subject(s)
Hodgkin Disease/radiotherapy , Radiotherapy, High-Energy , Adolescent , Adult , Aged , Disease-Free Survival , Female , Follow-Up Studies , Heart Diseases/etiology , Heart Diseases/mortality , Humans , Male , Middle Aged , Neoplasms, Radiation-Induced/epidemiology , Neoplasms, Radiation-Induced/etiology , Neoplasms, Second Primary/epidemiology , Neoplasms, Second Primary/etiology , Radiotherapy, High-Energy/adverse effects , Recurrence , Salvage Therapy , Survival Analysis , Survival Rate , Treatment Outcome
16.
J Immunol ; 159(10): 4943-51, 1997 Nov 15.
Article in English | MEDLINE | ID: mdl-9366420

ABSTRACT

Determination of immunodominant epitopes of MHC class I-restricted self-Ags and elucidation of TCR contact residues is of potential importance in providing a means of manipulating the immune response to self-Ags in human autoimmune diseases. A computer algorithm was used to examine the sequences of the two major encephalitogenic proteins of myelin, MBP and PLP, for HLA-A2 binding motifs. Thirty-eight peptides with HLA-A2.1 binding motifs were synthesized and their binding to HLA-A2.1 was measured. A panel of HLA-A2-restricted T cell clones directed against the PLPp80-88 epitope, which exceeded the binding affinity of the other myelin-peptides tested by at least one order of magnitude, was generated. Using a set of analogue peptides with single amino acid substitutions, we detected a distinct pattern of TCR contact residues for each clone. Surprisingly, modification of different presumed TCR contact residues generated superagonist peptides, which are defined as peptides with equal or lower MHC binding affinity to HLA-A2 that induce half-maximal effector responses at 100-fold lower concentrations than the original peptide. These agonist peptides could drive cytotoxic T cell clones to proliferate, secrete cytokines, and clonally expand at concentrations at which the native peptide induced only cytotoxic responses. The proliferation induced by the superagonist peptides gives additional evidence that the clonal expansion of CD8 T cell clones may in part be regulated on the level of Ag recognition by the TCR.


Subject(s)
Autoantigens/metabolism , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Peptides/agonists , Peptides/metabolism , Amino Acid Substitution , Autoantigens/immunology , Cell Line , Clone Cells , Cytotoxicity, Immunologic , HLA-A2 Antigen/genetics , HLA-A2 Antigen/immunology , HLA-A2 Antigen/metabolism , Humans , Interferon-gamma/metabolism , Interleukin-4/metabolism , Ligands , Multiple Sclerosis/immunology , Myelin Basic Protein/agonists , Myelin Basic Protein/immunology , Myelin Basic Protein/metabolism , Peptides/immunology , Proteolipids/agonists , Proteolipids/immunology , Proteolipids/metabolism , Receptors, Antigen, T-Cell/metabolism
17.
J Immunol ; 157(12): 5269-76, 1996 Dec 15.
Article in English | MEDLINE | ID: mdl-8955172

ABSTRACT

Induction of T cell anergy is thought to occur during activation in the absence of adequate costimulation. Here we demonstrate induction of anergy in a CD8 T cell clone by its cognate Ag in the presence of B7-1 and B7-2 costimulation. Primary activation of a CD28+CD8+ T cell clone by either human T cell lymphotrophic virus type I (HTLV-I) Tax11-19 peptide-pulsed EBV-transformed B cells, CD40L-stimulated B cells, or T cells was sufficient to induce complete unresponsiveness to a secondary Ag challenge. This was not caused by lack of B7 costimulation since the APCs expressed B7-1 and B7-2 and failed to induce anergy in an MBP peptide 84-102-reactive CD4 T cell clone. While anergic CD8 T cells did not proliferate, they retained their ability to lyse peptide-pulsed target cells. However, Ag stimulation failed to induce IL-2 mRNA transcription and IL-2 secretion, although immediate early tyrosine phosphorylation was normal and anti-CD3 cross-linking induced identical levels of CD40L expression in anergized and non-anergized CD8 T cells. Secondary Ag stimulation in the presence of exogenous IL-2, however, resulted in normal proliferative response. Moreover, while stimulation of CD8 T cells with PHA and B cells induced anergy, CD8 T cell stimulation with PHA and mononuclear cells failed to do so. In addition, the presence of mononuclear cells during the exposure of CD8 T cells to peptide-pulsed B cells prevented the induction of anergy. Together, our observations demonstrate that at least a subpopulation of CD8 T cells are anergized when costimulation is provided by B cells or T cells.


Subject(s)
Antigen-Presenting Cells/immunology , B-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Clonal Anergy , B7-1 Antigen/immunology , CD40 Ligand , Cell Line , Cytotoxicity, Immunologic , Gene Expression , Humans , Immunologic Memory , Interleukin-2/genetics , Lymphocyte Activation , Membrane Glycoproteins/immunology , Receptors, Antigen, T-Cell/physiology , Signal Transduction , Transcription, Genetic
18.
Antimicrob Agents Chemother ; 40(3): 763-6, 1996 Mar.
Article in English | MEDLINE | ID: mdl-8851607

ABSTRACT

Ceftazidime has proven to be effective for the treatment of bacterial meningitis caused by multiresistant gram-negative bacteria. Since nosocomial central nervous system infections are often accompanied by only a minor dysfunction of the blood-cerebrospinal fluid (CSF) barrier, patients with noninflammatory occlusive hydrocephalus who had undergone external ventriculostomy were studied (n = 8). Serum and CSF were drawn repeatedly after the administration of the first dose of ceftazidime (3 g over 30 min intravenously), and concentrations were determined by high-performance liquid chromatography by using UV detection. The concentrations of ceftazidime in CSF were maximal at 1 to 13 h (median, 5.5 h) after the end of the infusion and ranged from 0.73 to 2.80 mg/liter (median, 1.56 mg/liter). The elimination half-lives were 3.13 to 18.1 h (median, 10.7 h) in CSF compared with 2.02 to 5.24 h (median, 3.74 h) in serum. The ratios of the areas under the concentration-time curves in CSF and serum (AUCCSF/AUCS) ranged from 0.027 to 0.123 (median, 0.054). After the administration of a single dose of 3 g, the maximum concentrations of ceftazidime in CSF were approximately four times higher than those after the administration of 2-g intravenous doses of cefotaxime (median, 0.44 mg/liter) and ceftriaxone (median, 0.43 mg/liter) (R. Nau, H. W. Prange, P. Muth, G. Mahr, S. Menck, H. Kolenda, and F. Sörgel, Antimicrob. Agents Chemother. 37:1518-1524, 1993). The median AUCCSF/AUCS ratio of ceftazidime was slightly below that of cefotaxime (0.12), but it was 1 order of magnitude above the median AUCCSF/AUCS of ceftriaxone (0.007) (Nau et al., Antimicrob. Agents Chemother. 37:1518-1524, 1993). The concentrations of ceftazidime observed in CSF were above the MICs for most Pseudomonas aeruginosa strains. However, they are probably not high enough to be rapidly bactericidal. For this reason, the daily dose should be increased to 12 g in cases of P. aeruginosa infections of the central nervous system when the blood-CSF barrier is minimally impaired.


Subject(s)
Ceftazidime/cerebrospinal fluid , Ceftazidime/pharmacokinetics , Cephalosporins/cerebrospinal fluid , Cephalosporins/pharmacokinetics , Ventriculostomy , Adult , Aged , Ceftazidime/administration & dosage , Cephalosporins/administration & dosage , Female , Half-Life , Humans , Hydrocephalus/surgery , Infusions, Intravenous , Male , Middle Aged
19.
Leukemia ; 6(8): 828-33, 1992 Aug.
Article in English | MEDLINE | ID: mdl-1640736

ABSTRACT

Chemical inducers of the differentiation are known to cause an early transient decrease in c-myc and c-myb mRNA levels in Friend erythroleukemia cells preceding the down-regulation of c-myc and c-myb expression in the course of irreversible terminal differentiation. We therefore investigated the early effect of the potent differentiation-inducing anthracycline antitumor antibiotic, aclacinomycin A, on the c-myc and c-myb mRNA levels in the Friend cell line, F4-6, using Northern blot analysis. Aclacinomycin A induced a rapid decrease in the levels of c-myc and c-myb transcripts within 0.5-1 h and 2-3 h, respectively. The time course of decline in c-myc and c-myb expression was similar to that observed with dimethylsulfoxide or after transcription blockage brought about by a high concentration of actinomycin D. By 12 to 18 h after aclacinomycin A exposure, the c-myc and c-myb mRNA levels had returned to about pretreatment levels. When the cells were treated with adriamycin, an anthracycline that reduces cell proliferation in F4-6 cells without increasing differentiation, an early decrease in c-myc and c-myb expression was not observed. These results suggest that the transient decrease in c-myc and c-myb mRNA levels in F4-6 cells may be an early differentiation-related biochemical effect of aclacinomycin A.


Subject(s)
Aclarubicin/pharmacology , Genes, myc/drug effects , Leukemia, Erythroblastic, Acute/metabolism , Oncogenes/drug effects , Animals , Cell Differentiation/drug effects , Dimethyl Sulfoxide/pharmacology , Doxorubicin/pharmacology , Friend murine leukemia virus , Gene Expression/drug effects , Hemoglobins/biosynthesis , Kinetics , Leukemia, Erythroblastic, Acute/pathology , Mice , RNA, Messenger/biosynthesis , RNA, Neoplasm/biosynthesis , Tumor Cells, Cultured
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