bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of human IgG autoantibodies specific for IL-10
Authors: Menetrier-Caux C , Briere F , Jouvenne P , Peyron E , Peyron F , Banchereau J
Published: November 2003

Since autoantibodies to IL-1α, interferon-alpha (IFN-α) and IL-6 have been described, this study concentrated on the search for autoantibodies to hIL-10 using an assay based on the precipitation of 125I-hIL-10 anti-IL-10 autoantibody complexes using Protein G-Sepharose. Among 1860 tested sera, only seven were found to specifically precipitate IL-10, thus indicating the rare occurrence of such autoantibodies. Four of those seven anti-IL-10 autoantibody sera were specific for hIL-10, two recognized both human and viral IL-10, while the last one recognized human, viral and murine IL-10, thus suggesting the existence of at least three different epitopic specificities. The purification of anti-IL-10 autoantibody from one serum demonstrated the existence of a single (IgG1, λ) autoantibody that neutralized IL-10 biological activity. Thus, autoantibodies to IL-10 may represent natural antagonists to IL-10.
Effect of low dose UVB irradiation on the migratory properties and functional capacities of human skin dendritic cells
Authors: Richters C D , Reits E A J , van Pelt A M , Hoekstra M J , van Baare J , du Pont J S , Kamperdijk E W A
Published: November 2003

We recently described the ‘spontaneous’ migration of skin dendritic cells out of human split skin during culture. Since newly infiltrating cells from the circulation are excluded, this in vitro model is very suitable for studying the effect of UVB irradiation on the migratory properties, phenotype and functional capacities of skin cells. In the present study, we show that UVB irradiation of the skin before the culture period results in a significantly lower number of migrated cells that could be obtained compared with untreated skin. Relatively more dendritic cells of the population that migrated from UVB-irradiated skin were of dermal origin, as indicated by a higher percentage of CD1b+ cells. These data imply that UVB irradiation inhibits migration, especially of the epidermal Langerhans cells. Ultrastructural analysis of the irradiated skin revealed that the UVB dose used did not cause any directly visible damage to the cells. However, the cell population that had migrated from UVB-irradiated skin showed a significantly lower capacity to stimulate allogeneic T cells. This was not due to a lower expression of MHC class II on these cells. The percentage of cells expressing B7.1, B7.2 and LFA-3 was decreased in the population migrated from irradiated skin. The possible mechanism underlying the UVB-induced suppression is discussed.
Thyroid peroxidase autoantibody epitopic ‘fingerprints’ in juvenile Hashimoto’s thyroiditis: evidence for conservation over time and in families
Authors: Jaume J C , Burek C L , Hoffman W H , Rose N R , McLachlan S M , Rapoport B
Published: November 2003

In Hashimoto’s thyroiditis, the humoral component is manifest by autoantibodies to thyroid peroxidase (TPO). Epitopic ‘fingerprinting’ of polyclonal serum TPO autoantibodies has been facilitated by the molecular cloning and expression as Fab of a repertoire of human TPO autoantibody genes. To investigate whether TPO autoantibody fingerprints are (i) stable over long periods of time (∼15 years), and (ii) inherited, we studied a cohort of nine patients with juvenile Hashimoto’s thyroiditis and 21 first degree relatives of four of these patients. Fingerprints were determined by competition between four selected Fab and serum autoantibodies for binding to 125I-TPO. Regardless of titre, the TPO epitopic profile was stable in 10/12 individuals whose TPO autoantibody levels were sufficient for analysis on two or three occasions over 12–15 years. Although the TPO epitopic fingerprint profiles in two families raised the possibility of inheritance, overall the data from all four families did not reveal an obvious pattern of genetic control. In no family was the TPO epitopic fingerprint associated with HLA A, B or DR. In conclusion, TPO autoantibody epitopic fingerprints are frequently conserved over many years. Studies on additional families are necessary to establish whether or not the epitopic profiles of TPO autoantibodies are inherited.
Immunohistological study of the depressed cutaneous DTH response in sheep naturally infected with an ovine lentivirus (Maedi-Visna virus)
Authors: Pyrah I T G , Watt N J
Published: November 2003

The gross and immunohistological characteristics of the purified protein derivative (PPD)-induced cutaneous DTH reaction were studied in a group of sheep naturally infected with Maedi-Visna virus (MVV), and compared with reactions obtained in a matched control group. There was a marked, but variable, depression in the DTH lesion in the MVV group associated with a decreased density of polymorphonuclear neutrophils (PMN) and CD4+ cells in the early reaction. There were no significant differences in the densities of CD8+, γ/δ T cells, macrophages, B cells and MHC class II-expressing cells. This work indicates that there is a significant alteration in the initial trafficking of PMN and CD4+ cells into a DTH response area in sheep infected with MVV.
Proliferation of distinct human T cell subsets in response to live, killed or soluble extracts of Mycobacterium tuberculosis and Myco. avium
Authors: Esin S , Batoni G , Källenius G , Gaines H , Campa M , Svenson S B , Andersson R , Wigzell H
Published: November 2003

The proliferative responses of distinct cell subsets from healthy, bacille Calmette–Guérin (BCG)-vaccinated blood donors were assessed after in vitro stimulation with live or UV-killed Mycobacterium tuberculosis and Myco. avium or with soluble extracts obtained from either mycobacterial species. Proliferation of cell subsets was evaluated by flow cytometric determination of 5-bromo-2′-deoxy-uridine incorporation into DNA and simultaneous identification of surface phenotypic markers. In the presence of monocytes, the response to whole (live or killed) bacteria was characterized by a predominant proliferation of CD4+αβ+ T cells and, to a lesser extent, of CD8+αβ+ T cells. Proliferation of CD8+αβ+ T cells was primarily elicited by live rather than killed bacilli (P < 0.05). Conversely, when soluble bacterial extracts were used as stimulators, a preferential proliferation of γδ+ T cells, expressing predominantly Vγ9+ and Vδ2+ T cell receptor chains, was recorded. Moreover, when monocyte-depleted cell populations were directly cultured with live bacteria, a marked proportion of CD3–CD16+ (natural killer (NK)) cells was detected among the responding cells. Although both αβ, γδ and NK cells have been previously shown to react with mycobacteria in vitro, their relative contributions to the response have been difficult to assess. Using a flow cytometric technique which allows direct identification of proliferating cells within complex cell populations, our study demonstrates significant differences in the ability of various mycobacterial antigen preparations to elicit proliferation of distinct cell subsets.
Selective CD4+ T cell deletion after specific activation in HIV-infected individuals; protection by anti-CD28 monoclonal antibodies
Authors: Cottrez F , Capron A , Groux H
Published: November 2003

AIDS is characterized by a progressive decline in the number of CD4+ T cells. This is preceded by an early selective defect in the proliferation of these cells to recall antigens [1–3], pokeweed mitogen (PWM) [4–6] and to superantigens (SAg) [4,7]. In contrast, the proliferative response to phytohaemagglutinin (PHA) remains intact [1,2,5]. We and others have shown that the proliferative defect in response to some stimuli was in fact due to the induction of cell death [4,7]. The activation-induced cell death mechanism that explains the proliferative defects observed in vitro might also account for the progressive in vivo deletion of CD4+ T cells. Indeed, studies performed on different models of primates have shown that induction of cell death in CD4+ T cells was detected only when T cells were isolated from animals infected with a type of retrovirus that induces an AIDS-like disease [8]. This correlation prompted us to analyse further the mechanism of HIV-induced activation cell death to determine the specificity and rate of induction of cell death. T cells from HIV-infected individuals were activated with superantigens and the Vβ T cell receptor (TCR) expression analysed. Data presented here show that cell death is restricted to activated CD4+ T cells, and does not affect bystander cells. More importantly, addition of anti-CD28 MoAb specifically inhibited the induction of apoptosis, raising possibilities for therapy.
Soluble products of inflammatory reactions are not induced in children with asymptomatic Plasmodium falciparum infections
Authors: Jakobsen P H , Mckay V , N'Jie R , Olaleye B O , D'Alessandro U , Bendtzen K , Schousboe I , Greenwood B M
Published: November 2003

A proportion of children with Plasmodium falciparum infection have a high parasitaemia without accompanying fever, indicative of different clinical thresholds of parasitaemia. Higher levels of IL-10, IL-1Ra and sIL-4R but not sIL-2R were found in children with P. falciparum malaria, compared with levels in children with asymptomatic P. falciparum infections and in healthy children. Concentrations of IL-10 and IL-1Ra were correlated with levels of parasitaemia, but the association of cytokine levels with disease was independent of the association with parasitaemia. Children may tolerate a high parasitaemia by neutralizing the parasite-derived toxins. When studying potential anti-toxic molecules we found that children with symptomatic infections had lower concentrations of a phospholipid-binding molecule, β2-glycoprotein I (β2-GPI), compared with children with asymptomatic infections or healthy children. In conclusion, cytokines were found in much higher concentrations in children with symptomatic P. falciparum malaria than in children with asymptomatic infections, whilst the former had lower concentrations of β2-GPI.
Peptide immunization in humans: a combined CD8+/CD4+ T cell-targeted vaccine restimulates the memory CD4 T cell response but fails to induce cytotoxic T lymphocytes (CTL)
Authors: Brander C , Corradin G , Hasler T , Pichler W J
Published: November 2003

Immunization with short antigenic peptides represents a potential strategy to induce peptide-specific CTL in vivo. In this study, a synthetic vaccine consisting of an HIV-derived, HLA-A2.1-binding CTL epitope and a tetanus toxin-derived T helper epitope was evaluated for its capacity to induce peptide-specific CTL in humans. Thirteen volunteers were immunized and boosted twice with 100 μg of the CTL epitope plus 300 μg of the T helper peptide (p30). Peripheral blood mononuclear cells (PBMC) were regularly analysed for cytotoxic and proliferative responses before, between and after the immunizations, and the serum was tested for anti-peptide antibodies. No unequivocal induction of HIV peptide-specific CTL in any of the volunteers was observed. However, a wide pattern of mild and transient side reactions was observed, ranging from local redness at the injection site to generalized exanthema, myalgias, arthralgias and fever. The side-effects were related to the T helper epitope, as they were similar to the side-effects experienced after tetanus immunization, correlated to the magnitude of the p30-specific in vitro proliferative response, and occurred only if p30 was co-injected. No antibodies against the HIV-derived peptides nor against p30 were detectable in the serum after repeated immunizations. The data suggest that the CTL peptide, at the concentration used in this study, failed to induce a cytotoxic immune response in vivoalthough the T helper peptide seems to be capable of restimulating the specific memory T cells.
In vitro activation of antigen-presenting cells (APC) by defined composition of Quillaja saponaria Molina triterpenoids
Authors: Behboudi S , Morein B , Villacres-Eriksson M
Published: November 2003

The capacity of adjuvants to stimulate cytokine production by APC is important for the initiation of the immune response. Novel adjuvant formulations based on the iscom technology have been developed using selected triterpenoid components from Quillaja saponaria Molina. Five of these new Quillaja formulations were used to prepare matrix (an antigen-free particle) and tested for their capacity to stimulate IL-1 secretion by murine peritoneal cells in vitro. The formulation denominated QH 7.0.3 was superior to the other matrix formulations, including the original spikoside matrix. The QH 7.0.3 formulation in iscoms containing influenza virus envelope antigens induced IL-1 secretion more efficiently than the antigen-free matrix, or a mixture of matrix and viral antigens, or the free Quillaja components of similar composition. Compared with adjuvants known as IL-1 inducers, QH 7.0.3 flu-iscoms were as efficient as the most prominent IL-1 inducer, i.e. lipopolysaccaride (LPS) and superior to cholera toxin (CT) and muramyl dipeptide (MDP). These results indicate that the composition per se of triterpenoids included in iscoms or matrix has a prominent influence on the level of APC activation which may result in qualitatively different immune responses in vivo
Analysis of Vκ genes in rheumatoid arthritis (RA) synovial B lymphocytes provides evidence for both polyclonal activation and antigen-driven selection
Authors: Moyes S P , Brown C M , Scott B B , Maini R N , Mageed R A
Published: November 2003

To define mechanisms of sustained activation of synovial B lymphocytes in RA, we studied hybridomas established from the local synovial B cell repertoire of two RA patients for Vκ gene expression and for antigen-binding specificity. The analyses revealed that members of the main Vκ families (I, II and III) were utilized at frequencies consistent with random Vκ gene family use. Furthermore, although the hybridomas expressed genes frequently seen in response to other self- and exogenous antigens, only one VκI- and two of three VκIII-expressing hybridomas exhibited reactivity with self-antigens. Nucleotide sequence analysis revealed that all hybridomas, with the exception of rheumatoid factor (RF)-producing hybridomas, expressed Vκ genes highly related to known germ-line genes (99.3–100% homology) and that diversity was generated by deletions and random nucleotide insertions at the Vκ–Jκ junction. Examination of the few nucleotide changes seen within the Vκ genes revealed a predominance of silent to replacement changes. Moreover, most of these changes can be attributable either to allotypic variations or to limited random nucleotide replacements independent of antigen selection. In contrast, one IgG-RF (B4D8) exhibited predominantly replacement nucleotide changes in the complementarity-determining regions, suggestive of antigen-driven selection. The random expression of immunoglobulin variable region genes with no, or little, evidence of mutation in the synovial B lymphocyte repertoire, including natural polyreactive antibodies, alongside mutated IgG-RF, suggest that both polyclonal activation and antigen-driven responses occur in RA synovia.
Activation of epitope-specific memory cytotoxic T lymphocyte responses by synthetic peptides
Authors: Reali E , Guerrini R , Giori B , Borghi M , Marastoni M , Tomatis R , Traniello S , Masucci M G , Gavioli R
Published: November 2003

Cytotoxic T lymphocytes (CTL) recognize antigens as short peptides selected for presentation by their ability to bind to MHC class I molecules. Polyclonal Epstein–Barr virus (EBV)-specific memory CTL responses, reactivated from blood lymphocytes of HLA-A11-positive individuals by stimulation with the autologous EBV-transformed lymphoblastoid cell line (LCL), are often dominated by reactivities directed to the peptide epitope IVTDFSVIK (IVT), corresponding to amino acids 416–424 of EBV nuclear antigen-4 (EBNA4). We now report the selective activation of IVT-specific CTL by stimulation of lymphocytes with the corresponding synthetic peptide. A more than 10-fold increase in frequency of CTL clones with this specificity (from 8% to 96%) was obtained when the peptide was presented by HLA-A11-transfected T2 cells (T2/A11). Titration of synthetic peptide in cytotoxic assay demonstrated that clones activated under these conditions are as efficient as clones activated by conventional LCL stimulations. Induction of memory CTL responses required low surface density of MHC : peptide complexes, since reactivation was achieved by stimulation with T2/A11 cells pulsed with concentrations of peptide that are suboptimal for induction of target cell lysis. This protocol of activation revealed the presence of IVT-specific CTL precursors in a donor that failed to mount an IVT-specific response upon stimulation with the autologous B95.8 virus-transformed LCL. The results suggest that stimulation with synthetic peptide epitopes can be efficiently used for induction of memory CTL responses, and may be particularly helpful for the selective expansion of subdominant CTL specificities.
Clinical features of anti-chromo antibodies associated with anti-centromere antibodies
Authors: Iwai T , Muro Y , Sugimoto K , Matsumoto Y , Ohashi M
Published: November 2003

Anti-chromo antibodies (AChA) are autoantibodies accompanying anti-centromere antibodies (ACA). We determined the frequency and clinical significance of AChA in autoimmune rheumatic diseases. Serum samples from 252 patients with rheumatic diseases were examined by immunoblotting with HeLa nuclear extract and with recombinant N-terminus of 25-kD chromo protein (p25). AChA were detected in 28 (36%) of 77 sera with ACA. AChA were found only in ACA-positive sera. Twenty-two (79%) of 28 recognized a recombinant N-terminal portion of p25, including the chromo domain which is conserved among species. AChA were related to leucopenia, thrombocytopenia, elevated erythrocyte sedimentation rate, and existence of Sjögren's syndrome (SS). In ACA-positive patients, AChA might be a serologic indicator of systemic sclerosis (SSc), having features of systemic lupus erythematosus and/or SS or diseases other than SSc.
Cytokine mRNA expression in the liver of patients with primary biliary cirrhosis (PBC) and chronic hepatitis B (CHB)
Authors: Shindo M , Mullin G E , Braun-Elwert L , Bergasa N V , Jones E A , James S P
Published: November 2003

The expression of cytokine mRNA species was determined in liver biopsies from six normal subjects, 18 patients with PBC and 14 patients with hepatitis B e antigen (HBeAg)-positive CHB using a reverse transcriptase-polymerase chain reaction (RT-PCR) technique. cDNA, obtained by reverse transcription using oligo d(T) primers, was amplified by PCR using primers specific for the coding region of seven different cytokines (IL-1, IL-2, IL-4, IL-5, IL-6, interferon-gamma (IFN-γ), tumour necrosis factor-alpha (TNF-α)). The abundance of some cytokines (IL-2, IL-4, IL-5 and IFN-γ) was also estimated by semiquantitative RT-PCR, using as standards dilutions of synthetic cytokine mRNA transcripts, that could be distinguished electrophoretically from respective native cytokine mRNAs. Hepatic inflammation was assessed by a semiquantitative histologic score and by amplification of mRNA for T cell receptor (TCR)-α. mRNAs for IL-1 and IL-6 were detected in only one control liver. In CHB, mRNAs for IL-1, IL-2, IL-4, IL-5 and IFN-γ were detected in 43%, 60%, 80%, 20%, and 54% of biopsies, respectively. mRNA for IFN-γ and IL-4, but not IL-1, tended to be associated with severe inflammation. In five biopsies semiquantitative analyses revealed increased levels of mRNA for TCR-α and, when transcripts were detectable, high levels of mRNA for IFN-γ and IL-4. In PBC, mRNA for IFN-γ was detected in 60% of biopsies, but no mRNAs for IL-1, IL-2, IL-4, IL-5, or IL-6, or for TNF-α, were detected. Semiquantitative analyses revealed that absolute levels of mRNA for IFN-γ tended to correlate with the severity of hepatic inflammation. The results suggest that: (i) there may be fundamental differences in the roles that cytokines play in the hepatic inflammatory processes of PBC and CHB; and (ii) while hepatic IFN-γ mRNA expression is not specific for PBC, IFN-γ may play a prominent role in the immunopathogenesis of PBC.
Tracking of the V4–34 (VH4–21) gene in human tonsil reveals clonal isotype switch events and a highly variable degree of somatic hypermutation
Authors: Chapman C J , Mockridge C I , Hamblin T J , Stevenson F K
Published: November 2003

The V4–34 (VH4–21) gene has been found to encode certain IgM autoantibodies, and is mandatory for pathological IgM anti-erythrocyte antibodies of I/i specificity. The gene is also commonly used by normal IgM-positive B lymphocytes, but its involvement in B cells which have undergone class switching to IgG or IgA is less clear. In order to track V4–34 gene usage and class switching events during a normal immune response, we have probed RNA in a limited area of human tonsil. Results indicate that the V4–34 gene undergoes class switching to IgG or IgA, with the progeny either remaining unmutated or containing large numbers of somatic mutations. Mutational patterns indicate possible ‘hot spots’, and some mutations appear deleterious. At the level of individual B cells, we have tracked a clonal isotype switch event from IgM to IgA, with each retaining close to germ-line configuration. In addition, we have followed a clonal switch from a mutated IgM to IgG, with no further accumulation of somatic mutations. These data indicate that the V4–34 gene is involved in a maturing immune response, and that the routes to production of IgG or IgA antibodies are various.
Metabolic disturbance and sensitivity to endotoxin in patients with advanced cancer: relationship to lymphocyte reactivity, tumour necrosis factor (TNF) production and survival
Authors: Gough D B , Fearon K C H , Carter D C
Published: November 2003

Increased TNF production and impaired lymphocyte function have been individually linked with metabolic disturbance, endotoxaemia and mortality in humans. The inter-relationship between these observations was investigated in humans with cancer. In 13 patients with metastatic colorectal cancer and seven healthy volunteers, observations (n=23) included peripheral blood mononuclear cell (PBMC) TNF production, IL-2 production and phytohaemagglutinin (PHA) response; the acute-phase protein response (APPR) (serum C-reactive protein (CRP), albumin, CRP/albumin ratio), and survival. APPR correlated with survival (CRP, r=−0.689, P=0.006; CRP/albumin, r=−0.758, P=0.002; albumin, r=0.655, P=0.011), but not with TNF production. TNF production in response to in vitro endotoxin correlated with impaired lymphocyte function in patients (r=0.567, P=0.043) and in the whole group (r=0.65, P=0.001). The ratio (basal PBMC TNF production)/(lymphocyte function) correlated with CRP (r=0.569, P=0.042), CRP/albumin (r=0.617, P=0.025), endotoxin sensitivity (r=0.567, P=0.043) and survival (r=−0.545, P=0.038) in patients, and the whole group (P<0.002). Impaired lymphocyte function may influence TNF production, endotoxin sensitivity and metabolic disturbance in humans with cancer. (r=Spearman correlation coefficient.)
Morphologically and functionally intact dendritic cells can be derived from the peripheral blood of aged individuals
Authors: Steger M M , Maczek C , Grubeck-Loebenstein B
Published: November 2003

Dendritic cells are antigen-presenting cells (APC), which are crucial for the initiation of an immune response. In spite of the well known decline of immune function in old age, no information is yet available on whether dendritic cells are also affected by the ageing process. It was therefore the aim of this study to compare peripheral blood dendritic cells (DC) from old and young healthy individuals. Using granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-4, DC were propagated from peripheral blood mononuclear cells (PBMC). The obtained cell populations had a typical dendritic morphology and expressed HLA class I and class II, CD23, CD32, CD40, CD44 and CD54, but not CD3 and CD19. Larger numbers of DC were obtained from old individuals than from young ones in spite of a similar expression pattern of surface molecules. DC from aged persons also survived better under in vitro culture conditions. When tested for their antigen-presenting capacity, DC from young and old individuals were equally effective in inducing the proliferation of tetanus toxoid-specific T cell clones after antigenic stimulation. Peripheral blood DC from aged individuals may thus still function as powerful APC. They may represent useful tools for immunotherapy in the aged.
Anti-inflammatory properties of human serum IgA: induction of IL-1 receptor antagonist and FcαR (CD89)-mediated down-regulation of tumour necrosis factor-alpha (TNF-α) and IL-6 in human monocytes
Authors: Wolf H M , Hauber I , Gulle H , Samstag A , Fischer M B , Ahmad R U , Eibl M M
Published: November 2003

A deregulated expression and/or release of large amounts of inflammatory cytokines such as IL-1 and TNF-α accounts for most pathophysiological events in a variety of systemic inflammatory diseases, the effect being mediated by the interaction of these cytokines with their respective receptors. IL-1 receptor antagonist (IL-1Ra), mainly produced by monocytes/macrophages, is an inhibitor of IL-1 activity. The present study shows that human serum IgA induces significant IL-1Ra release in human peripheral blood mononuclear cells and adherent monocytes. IgA induced higher levels of IL-1Ra than Haemophilus influenzae type b (Hib) expressing lipopolysaccharide (LPS), purified LPS or phorbol myristate acetate (PMA), without induction of IL-1β release, and even inhibited LPS-induced IL-1β release. Induction of IL-1Ra by IgA could be detected both at the mRNA and protein levels in resting and activated monocytes. Ligation of FcαR with MoAb MY-43 or treatment with human serum IgA induced protein tyrosine phosphorylation in human monocytes, and herbimycin A, a specific inhibitor of protein tyrosine kinase activity, inhibited IgA-induced IL-1Ra production, suggesting that FcαR-mediated induction of tyrosine phosphorylation is required for the IgA-induced stimulation of IL-1Ra release. In addition, triggering of FcαR with MoAb specifically down-regulated TNF-α and IL-6 release in human monocytes activated with Hib. By the induction of IL-1Ra and down-regulation of the release of inflammatory cytokines such as IL-1β, TNF-α and IL-6, interaction of IgA with human monocytes may actively contribute to the regulation of the inflammatory response.
Low T cell reactivity to combined CD3 plus CD28 stimulation is predictive for progression to AIDS: correlation with decreased CD28 expression
Authors: Roos M TH L , Miedema F , Meinesz A A P , De Leeuw N A S M , Pakker N G , Lange J M A , Coutinho R A , Schellekens P TH A
Published: November 2003

In 219 HIV-1-infected men of the Amsterdam cohort we measured CD4+ T cell numbers and in vitro T cell responses to CD3 MoAbs with or without CD28 costimulation and phytohaemagglutinin (PHA). The value of these markers was estimated for disease progression within 4 years. CD28 expression on T cells has been related to T cell responses. CD28 costimulation considerably enhanced T cell reactivity (≈8–10-fold) with lower coefficients of variation compared with reactivity to CD3 MoAb alone (median 5 versus 20). T cell reactivity to CD3 plus CD28 MoAb was decreased during HIV-1 infection and was besides CD4+ T cell numbers the only independent predictor for progression to AIDS. Compared with the group with high CD4+ T cell numbers the relative risk (RR) for the group with intermediate levels was 2.28, with low levels 5.20. In the groups with intermediate and low CD3 plus CD28 responses the RR was 2.04 and 4.16, respectively. The combined RR for both was 4.65 and 21.63. The independence of this marker was confirmed when the group with low CD4+ T cell numbers was subdivided into groups with high, intermediate and low T cell responses. The expansion of CD8+CD28− T cells was already apparent in HIV− homosexual men, but CD8+CD28+ T cells specifically decreased in patients with AIDS. CD28 expression on T cells correlated moderately with T cell responses to CD3 plus CD28 MoAb. T cell reactivity to CD3 MoAb in the presence of CD28 MoAb is a stronger prognostic marker than T cell reactivity to CD3 MoAb alone.
IL-2 signalling in T and natural killer (NK) cells associated with their class I-non-restricted killing activity
Authors: Yoneda K , Osaki T , Yamamoto T
Published: November 2003

The signal transduction of IL-2 in NK cells and T cells was compared. On 5 min incubation of these cells  with IL-2, we observed tyrosine phosphorylation of 105-kD and 110-kD proteins in NK cells and of 95-kD and 110-kD proteins in T cells. The phosphorylation reached maximal levels in 15 min in both NK and T cells, but the levels were higher in NK cells, which showed superior killing against Daudi cells. With this phosphorylation, p52shc was also tyrosine-phosphorylated and p21ras was activated by the short term (10 min) treatment of NK and T cells with IL-2. These signals were completely suppressed by anti-IL-2Rβ MoAb, but only slightly suppressed by anti-IL-2Rα MoAb, correlated with the suppression of the class-I-non-restricted cytotoxic activity of NK and T cells by these MoAbs. When tyrosine phosphorylation was inhibited by herbimycin A and genistein, the cytotoxic activities of NK and T cells were nearly completely suppressed. In addition, the tyrosine phosphorylation of JAK3 by IL-2 was more prominent in NK cells than in T cells, but JAK1, JAK2, STAT1α, STAT2 and STAT3 were not phosphorylated. These results indicate that the IL-2 signal flows downstream via both ras-dependent and ras-independent pathways and that the superior killing activity of NK cells depends on their high susceptibility to protein tyrosine phosphorylation by IL-2.
In vivo effects of cytokines on psoriatic skin grafted on nude mice: involvement of the tumour necrosis factor (TNF) receptor
Authors: Gilhar A , David M , Kalish R S , Weisinger G
Published: November 2003

Following engraftment of human involved psoriatic skin to nude mice there is a partial normalization of pathology associated with a loss of inflammatory leucocytes. However, the epidermis remains hyperproliferative, which may reflect a primary defect. The roles of TNF-α, IL-1 and IL-6 in epidermal hyperproliferation of grafted psoriatic lesions were investigated. Before and after treatment, grafts were analysed to determine epidermal thickness and labelling index (LI). HLA-DR, intercellular adhesion molecule-1 (ICAM-1), and TNF receptor (TNF-R; p75 and p55) expression were determined by immunoperoxidase staining. Psoriatic epidermis was found consistently to be negative for p55 TNF-R and p75 TNF-R before grafting. Following engraftment, TNF-R-positive cells (i.e. p55 by keratinocytes; p75 by epidermal dendritic cells) were identified throughout the epidermis. Higher numbers of p75 TNF-R epidermal dendritic cells were found in grafts following a course of TNF-α, IL-6 or IL-1 treatment. The p55 form of the TNF-R expressed by keratinocytes was significantly elevated after treatment with TNF-α or IL-6. HLA-DR and ICAM-1 were also expressed in these grafts. TNF-α, anti-IL-1, and anti-IL-6 treatment induced a marked decrease in the epidermal thickness and LI of psoriatic graft tissue, correcting the hyperproliferation associated with psoriatic epidermis. Supraphysiological levels of TNF-α may saturate and consequently down-regulate their own receptors, leading to a paradoxical inhibitory effect.
Inhibitory effect of salmeterol on the respiratory burst of adherent human neutrophils
Authors: Ottonello L , Morone P , Dapino P , Dallegri F
Published: November 2003

Human neutrophils, plated in fibronectin-coated wells and stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP), were found to undergo a massive and prolonged respiratory burst, as measured by monitoring superoxide production. The β2-agonist salmeterol inhibited the respiratory burst in a dose-dependent manner. In contrast, salbutamol was ineffective. Moreover, the neutrophil respiratory burst was partially suppressed by prostaglandin E2 (PGE2) and the phosphodiesterase type IV (PDE-IV) inhibitor RO 20-1724. When salmeterol was used in combination with PGE2 or RO 20-1724, additive inhibitory effects were observed. The inhibitory activity of salmeterol was not reversed in the presence of the β-blocker propranolol, and did not correlate with its ability of increasing cyclic AMP (cAMP) levels. Finally, the compounds used did not affect neutrophil adherence to fibronectin-coated wells. The results suggest that salmeterol is capable of down-regulating the neutrophil oxidative response to fMLP, also of co-operating with PGE2 and PDE-IV inhibitor RO 20-1724 in a manner not related to its β2-receptor binding activity. In other words, salmeterol displays neutrophil-directed effects, susceptible to be amplified by natural mediators such as PGE2 or PDE-IV inhibitors, consistent with possible anti-inflammatory properties of the drug.
Complement plays an essential role in shock following intestinal ischaemia in rats
Authors: Ikai M , Itoh M , Joh T , Yokoyama Y , Okada N , Okada H
Published: November 2003

Intestinal ischaemia lasting more than 30 min in rats causes fatal systemic shock. Systemic shock was suppressed by preadministration of cobra venom factor (CVF), which reduced the serum complement to less than 5% of the normal level, indicating that complement is involved in the syndrome. After complement activation, anaphylatoxins such as C3a and C5a are generated, and their activity is restricted by carboxypeptidases which remove C-terminal arginine from such bioactive peptides. As expected, preadministration of a carboxypeptidase inhibitor enhanced the systemic shock induced by the intestinal ischaemia. However, when the complement level was suppressed by CVF treatment, no fatal systemic shock was induced by the intestinal ischaemia even with preadministration of the carboxypeptidase inhibitor. These results indicate that complement plays a crucial role in systemic shock induced by intestinal ischaemia, and that anaphylatoxins generated by the complement activation should be involved in induction of the shock syndrome.
Expression of functionally active α4β1 integrin by thymic epithelial cells
Authors: Nieto M , Gómez M , Sánchez-Mateos P , Fernández E , Marazuela M , Sacedón R , Varas A , González-Amaro R , Zapata A G , Toribio M L , Sánchez-Madrid F
Published: November 2003

We have investigated the expression and function of the VLA-4 heterodimer α4β1, a member of the β1 integrin subfamily, on human thymic epithelial cells (TEC) derived from cortical epithelium. The expression of the α4 integrin chain was studied in four different cloned TEC lines derived from either  fetal or post-natal human thymus by both flow cytometry and immunoprecipitation techniques with anti-α4 MoAbs. All different cell lines assayed expressed significant levels of α4, as revealed by their reactivity with MoAbs specific for distinct α4 epitopes. The α4 subunit expressed by TEC was associated to β1 but not to β7 chain, and displayed the characteristic 80/70 kD pattern of proteolytic cleavage. The VLA-4 integrin in these cells was constitutively active in terms of adhesiveness to both fibronectin and vascular cell adhesion molecule-1 (VCAM-1). In addition, this heterodimer localized to punctate regions of the cell in the area of contact with the substratum, named point contacts assessed by staining with the anti-β1 activation epitope 15/7 MoAb. According to the cortical origin of the TEC lines expressing VLA-4, human thymus sections stained with different anti-α4 antibodies revealed the presence of cortical, and in smaller numbers medullary epithelial cells bearing α4 integrin. The expression of α4 in the thymus was also found in both adult and fetal rats, in which epithelial cells were also specifically stained. Altogether, our data show that VLA-4 is an additional component of the integrin repertoire of TEC, and suggest that it could have an important role in thymus epithelial cell–thymocyte interactions.
Blood monocyte activation in rheumatoid arthritis: increased monocyte adhesiveness, integrin expression, and cytokine release
Authors: Lioté F , Boval-Boizard B , Weill D , Kuntz D , Wautier J-L
Published: November 2003

Infiltration of the synovium by mononuclear cells, namely lymphocytes and monocytes, is one of the main features of rheumatoid arthritis (RA) and is considered to be responsible for the development of the disease. In this study in 31 consecutive patients with RA, we investigated whether peripheral blood monocytes exhibited markers of cellular activation related to cell migration. Using flow cytometry with the respective specific antibodies, we studied the expression of integrins CD11a, CD11b, CD11c, CD49d (VLA-4), and CD49e (VLA-5) on monocytes from patients with RA and from normal (N) subjects. IL-1β, IL-6, and tumour necrosis factor-alpha (TNF-α) production by cultured monocytes was measured by immunoassay. Adhesiveness of monocytes was studied on various surfaces (plastic, human fibronectin, gelatin-coated plasma, subendothelial matrix) and on cultured endothelial cells under basal conditions or after stimulation by IL-1β. An increased number of CD14+ monocytes (Mo) from RA patients expressed the CD11b molecule (RA Mo = 90.3%, N Mo = 83.4%, P < 0.005). The expression of CD11b on CD14+ monocytes was significantly increased in RA patients (median fluorescence intensity (FI): RA Mo = 145 (range 80–466) units; normal Mo = 95 (range 24–164) units; P < 0.003). Production of extracellular IL-1β and IL-6 by RA monocytes was significantly enhanced compared with monocytes from normal subjects (IL-1β : RA = 2.65 ± 0.91 ng/ml versusN = 1.35 ± 0.85 pg/ml, P < 0.05; IL-6: RA = 4.83 ± 0.90 ng/ml versusN = 2.40 ± 0.95 ng/ml, P < 0.05). Compared with normal monocytes, RA monocytes exhibited increased adhesion to the various surfaces studied (plastic, P < 0.01; fibronectin, P < 0.01; and gelatin-coated normal or RA plasma, P < 0.01) as well as to unstimulated (P < 0.01) and IL-1β-stimulated endothelial cells (IL-1β for 4 h, P < 0.05; IL-1β for 24 h, P < 0.05). In our study, blood monocytes from RA patients exhibited features of activation related to cell adhesion.
Spontaneous CD30 mRNA expression in peripheral blood mononuclear cells from atopic patients with high IgE serum levels
Authors: Esnault S , Benbernou N , Lavaud F , Guenounou M
Published: November 2003

CD30 is a surface molecule which can be expressed by normal B and T lymphocytes. Our study focused on the CD30 expression and release compared with IL-4 expression as well as CD23-α/β in peripheral blood mononuclear cells (PBMC) from atopic subjects and controls. Data showed a lack of CD30 mRNA expression in the PBMC of control subjects, while it was significantly expressed in those of 6/11 atopic patients. No substantial amounts of spontaneous soluble CD30 (sCD30) could be detected by ELISA in both atopic and control groups. Interestingly, CD30 mRNA expression in PBMC of allergic patients was positively correlated with IgE serum levels (r = 0.79, P = 0.003). Studies on purified B cells showed that CD30 was expressed mainly in CD19+B cells of allergic patients. These data suggest highly a potential functional significance of the CD30 molecule in IgE response during allergic diseases.
Heat shock-enhanced T cell apoptosis with heat shock protein 70 on T cell surface in multicentric Castleman's disease
Authors: Ishiyama T , Koike M , Akimoto Y , Fukuchi K , Watanabe K , Yoshida M , Wakabayashi Y , Tsuruoka N
Published: November 2003

We report here that T cells from patients with multicentric Castleman's disease (MCD) are sensitive to hyperthermia. T cells from two of three patients with MCD revealed DNA ladder formation and chromatin condensation following heat shock (30 min at 41.5°C). Peripheral blood mononuclear cells (PBMC) from the same MCD patients exhibited high levels of spontaneous apoptosis after 72 h in culture and elevated apoptosis after heat shock, as evaluated by a quantitative flow cytometric assay. Heat shock protein 70 (hsp70) was detected on the cell surface of T cells in all three patients after heat shock. Furthermore, hsp70 was detected on T cells in the two MCD patients with apoptosis even in the absence of heat shock. T cells from normal samples did not show either heat-shock-induced expression of cell-surface hsp70 or apoptosis. Thus, heat shock treatment augmented hsp70 expression on the cell surface of T cells and enhanced apoptosis. Our studies suggest that hyperthermia may influence the clinical course of MCD.
Macrophage-colony stimulating factor (M-CSF) enhances proteinuria and recruitment of macrophages into the glomerulus in experimental murine nephritis
Authors: Utsunomiya Y , Omura K , Yokoo T , Imasawa T , Kawamura T , Abe A , Hirano K , Mitarai T , Maruyama N , Sakai O
Published: November 2003

In this study, we examined the effects of macrophage-colony stimulating factor (M-CSF) on glomerular macrophages in lipopolysaccharide (LPS)-induced murine nephritis. Mice injected intraperitoneally with either M-CSF plus LPS, LPS alone, M-CSF alone or saline every day for 8 days were examined for the degree of urine albumin excretion and lymphocyte-function associated antigen-1-positive (LFA-1+) cells in peripheral blood as well as renal pathology. From our results, LPS or M-CSF combined with LPS emphasized the degree of proteinuria, glomerular deposition of immunoglobulins and mesangial proliferation, associated with accumulation of macrophages in the glomeruli. However, in immunohistological examination of kidneys from these nephritic mice, neither intercellular adhesion molecule-1 (ICAM-1), which may play an important role in the recruitment of macrophages into glomeruli, M-CSF receptor nor the number of LFA-1+ cells in peripheral blood was enhanced by M-CSF. On the other hand, M-CSF alone induced neither proteinuria nor any pathological changes and did not increase the number of glomerular Mac-1+ cells above that in saline-treated controls. These results indicate that M-CSF does not directly cause glomerulonephritis but might participate in accelerating the glomerular inflammatory process by stimulating a potent chemoattractant to recruit monocytes-macrophages into the glomeruli.
Testosterone inhibits immunoglobulin production by human peripheral blood mononuclear cells
Authors: Kanda N , Tsuchida T , Tamaki K
Published: November 2003

We studied the in vitro effect of testosterone on spontaneous immunoglobulin production by human peripheral blood mononuclear cells (PBMC). Testosterone inhibited IgG and IgM production by PBMC both from males and females. The inhibitory effect of testosterone was revealed at doses more than 1 nm, increased dose-dependently, and reached a plateau at 100 nm. At doses <1000 nm, testosterone did not reduce cell viability. Testosterone treatment reduced IgG production by 59.0% and that of IgM by 61.3% compared with control. Immunoglobulin production by B cells was also suppressed by testosterone, though the magnitude of the suppressive effect on B cells was lower than that on whole PBMC; testosterone-induced decrease of IgG production compared with control was 26.9% and that of IgM was 24.9%. Exogenous IL-6 partially restored the impaired immunoglobulin production of testosterone-treated PBMC; IgG production in testosterone culture was increased by IL-6 from 35.6% to 66.5% of control and that of IgM was also increased from 38.9% to 71.2%, respectively. Testosterone treatment reduced IL-6 production of monocytes by 78.4% compared with control, but neither affected that of T cells or B cells. These results suggest that testosterone may suppress immunoglobulin production of human PBMC directly by inhibiting B cell activity and indirectly by reducing IL-6 production of monocytes. It is thus indicated that this hormone may have protective and therapeutic effects on human autoimmune diseases.
Neutrophils in mucosal secretion are functionally active
Authors: Ebenfelt A , Lundqvist H , Dahlgren C , Lundberg C
Published: November 2003

The leucocytes in the secretion on the tonsillar surface have been regarded as inactivated and dying cells with no essential function in the defence of the underlying mucosa. In recent studies, we showed that in acute tonsillitis there are very few, if any, bacteria in the parenchyma, whereas in the secretion on the tonsillar surface there are huge numbers of bacteria and neutrophils, and furthermore, extensive phagocytosis. The present study was performed to elucidate the functional capacity of the neutrophils in the secretion on the tonsillar surface. Secretion samples were taken from the tonsillar surface of healthy volunteers with an imprint technique which allows transfer of secretion from the mucosa to a glass slide with maintained topographic position of the cells. The capacity of the neutrophils to respond to chemotactic stimuli and to phagocytize and further process labelled yeast particles was studied in this in vitro system. The results show that the neutrophils in the secretion have the same properties as in tissue, and also when having arrived in the secretion they can identify and attack new prey.
Differential clearance of glycoforms of IgG in normal and autoimmune-prone mice
Authors: Newkirk M M , Novick J , Stevenson M M , Fournier M-J , Apostolakos P
Published: November 2003

In order to understand better the origins of the elevated levels of the glycoform of IgG that lacks galactose on both arms of the oligosaccharide chain (G0%) located in the Fc, which occurs in man and mouse with age, and in particular in autoimmune disease, we investigated the clearance of two glycosylated forms of IgG2a and IgG1 in normal (BALB/c) and autoimmune-prone (MRL/lpr, MRL/+, and non-obese diabetic (NOD)) mice. To investigate the possibility of different rates of catabolism, enzymatically generated glycoforms of monomeric IgG1 and IgG2a (fully glycosylated or G0%), were iodinated and injected into the tail vein of the mice. We found that the G0% IgG2a remained in circulation significantly longer than the fully glycosylated variants, in all of the mouse strains tested. In contrast, the two forms of IgG1 had similar kinetics in all the autoimmune-prone mice, whereas in BALB/c, there was a longer half-life (t1/2) for G0% IgG1. These data suggest that there may be differences in the ability of the IgG glycoforms to bind to the Fcγ receptors, in particular FcγRI. The clearance rates were found to vary among the strains studied, with MRL/lpr having the fastest catabolic rates for all glycoforms and IgG subclasses tested. This appeared to be due to the presence of circulating IgG and IgM rheumatoid factors (RF). There were significantly increased frequencies and titres for both IgM and IgG RF in MRL/lpr mice compared with the other strains. In contrast, interferon-gamma, known to induce the FcγRI, was found to be similar in the sera, in all of the strains of mice examined. These results suggest that RF probably play an important biological function in the MRL/lpr mice and aid in the clearance of circulating IgG. Our study shows that the state of glycosylation of IgG affects the t1/2in vivo, and that by removing the terminal sugars (sialic acid and galactose), the antibody (IgG2a) will remain in circulation significantly longer. These observations may thus provide a partial explanation for the increase in relative percentage of this glycoform that occurs with age.