Herpes simplex virus type 1 infection induces upregulation of interleukin-23 (p19) mRNA expression in trigeminal ganglia of BALB/c mice.

We investigated the expression kinetics of several cytokines in trigeminal ganglia (TG) and in brains of BALB/c mice during the course of ocular herpes simplex virus type 1 (HSV-1) infection. All mice recovered from the infection within 2 weeks. The quantitative rapid real-time RT-PCR method was used to analyze interleukin-4 (IL-4), interferon-gamma (IFN-gamma), IL-12p35, IL-12p40, and the recently described IL-23 (p19) mRNA in TG, brain, and splenocyte samples. In TG, we found elevated expression of mRNA for IL-23 (p19) from early acute infection (day 3) to the beginning of the latent phase (day 14). The increase was not detected in brain or in the spleen. IL-4 expression occurred in both TG and brain from the beginning of the experiment to the latent phase. During the latent phase (days 14 and 31), IL-4 expression was significantly elevated in the brain when compared with the uninfected controls (p < 0.05). Considerable expression of IFN-gamma mRNA was detected in TG of mice during acute HSV-1 infection. The expression of IL-23 was detected also in the brains of the mice, even though no significant changes were found during the acute HSV-1 infection. This is, to our knowledge, the first report to show elevated expression of IL-23 (p19) mRNA (p < 0.05) during viral infection in TG of mice.     

A peptide inhibitor of vascular adhesion protein-1 (VAP-1) blocks leukocyte-endothelium interactions under shear stress

Vascular adhesion protein-1 (VAP-1) is an endothelial adhesion molecule mediating leukocyte interactions with blood vessels during leukocyte extravasation. Molecularly VAP-1 is a cell-surface-expressed ecto-enzyme belonging to the group of semicarbazide-sensitive amine oxidases (SSAO; EC 2.4.6.3), which deaminate primary amines. Here we asked whether peptides displaying a suitable free amine group could be a substrate or inhibitor of SSAO and thus regulate VAP-1-mediated leukocyte adhesion. On the basis of a molecular model of VAP-1, we designed synthetic peptides that fit to the substrate channel of VAP-1. One of these lysine-containing peptides effectively inhibits VAP-1-dependent lymphocyte rolling and firm adhesion to primary endothelial cells under physiologically relevant shear conditions. The same peptide inhibits the SSAO activity of endothelial and recombinant VAP-1 in a selective and long-lasting manner. We also show that all enzymatically active VAP-1 is displayed on the cell surface. Our results suggest that, in addition to soluble amines, specific cell-surface-bound molecules containing free NH(2) groups in a suitable position may modulate the enzymatic activity of SSAO. Moreover, the inhibitory peptide diminishes leukocyte interactions with endothelial cells under conditions of shear, and thus it may be useful to treat inflammatory conditions.     

Cloning of human T cells specific for measles virus haemagglutinin and nucleocapsid.

T cell lines specific for measles virus (MV) were generated from blood of two DR1/DR2 heterozygous healthy donors with a history of past measles infection. The antigenic specificity of 66 T cell clones derived from the lines was studied in a blastogenic assay using whole measles virus and two purified virus components, haemagglutinin and nucleocapsid. Thirty-nine of the clones were specific for one of the two purified antigens. None of the seven synthetic peptides covering 20% of the MV haemagglutinin amino acid sequence stimulated T cell clones with haemagglutinin specificity. Responsiveness of the majority of the clones were restricted by HLA-D/DR antigens, although two clones were isolated that responded only to MV antigens presented by autologous cells. Ten of 11 clones recognizing the nucleocapsid antigen were DR1-restricted, while the haemagglutinin antigen and whole measles virions were recognized more often in association with the DR2 antigen. These results indicate that much of the MV-specific memory T cell response is specific for the haemagglutinin and nucleocapsid virus antigens, with the DR antigen being the main restriction element involved.     

Induction of vascular adhesion protein-1 during liver allograft rejection and concomitant cytomegalovirus infection in rats

Vascular adhesion protein-1 (VAP-1) is an adhesion molecule controlling lymphocyte recirculation through high endothelial venules of the lymph nodes. It has also been shown to be induced and to mediate lymphocyte adhesion at sites of inflammation. We studied the expression of VAP-1 and two other inducible adhesion molecules ICAM-1 and VCAM-1 in our experimental model of rat liver allograft rejection and, in addition, the effect of concomitant rat cytomegalovirus (RCMV) infection on this expression. Expression of VAP-1, ICAM-1, and VCAM-1 was studied in rat liver allografts with or without RCMV infection, isografts, and normal rat liver. Immunoperoxidase technique and monoclonal antibodies including a novel anti-VAP-1 reagent were used. VAP-1 expression was induced by acute rejection in sinusoids, hepatocytes, and also in bile ducts, when compared to the isografts or normal liver, where only blood vessels were consistently positive. Sinusoidal and hepatocyte expression of VAP-1 was prolonged by the presence of RCMV. ICAM-1 and VCAM-1 expression was also induced by acute rejection. However, RCMV increased sinusoidal VCAM-1 expression compared to uninfected grafts. The present experimental study shows that VAP-1 is up-regulated in acute rejection of liver allografts, and that this up-regulation is prolonged by RCMV infection.     

Intrathecal synthesis of virus antibodies in multiple sclerosis patients.

A follow-up study on the intrathecal synthesis of viral antibodies in multiple sclerosis patients was made on 28 patients over a period of about 2 years. Serial serum and cerebrospinal fluid specimens were assayed for antibodies against measles, rubella, parainfluenza type 2, respiratory syncytial, mumps, influenza A, influenza B, adeno, and herpes simplex viruses by employing a solid-phase enzyme immunoassay technique. All patients had local antibody synthesis against one or more of the antigens studied. Rubella and measles virus antibodies were found with the highest frequency and were synthesized at the highest rate. Simultaneous intrathecal antibody synthesis against the greater number of the viruses studied was associated with higher local immunoglobulin G synthesis. A good overall correspondence in the fluctuations of the different viral antibodies synthesized intrathecally was usually found. Sometimes the changes in intrathecal antibody levels correlated well with the changes in immunoglobulin G index and sometimes not. These fluctuations could not be correlated with the clinical course of the disease. The results of this study suggest that the viral antibodies studied are not relevant to the etiology or the pathogenesis of multiple sclerosis.     

Function-blocking antibodies to human vascular adhesion protein-1: a potential anti-inflammatory therapy

Human vascular adhesion protein-1 (VAP-1) is a homodimeric 170-kDa sialoglycoprotein that is expressed on the surface of endothelial cells and functions as a semicarbazide-sensitive amine oxidase and as an adhesion molecule. Blockade of VAP-1 has been shown to reduce leukocyte adhesion and transmigration in in vivo and in vitro models, suggesting that VAP-1 is a potential target for anti-inflammatory therapy. In this study we have constructed mouse-human chimeric antibodies by genetic engineering in order to circumvent the potential problems involved in using murine antibodies in man. Our chimeric anti-VAP-1 antibodies, which were designed to lack Fc-dependent effector functions, bound specifically to cell surface-expressed recombinant human VAP-1 and recognized VAP-1 in different cell types in tonsil. Furthermore, the chimeric antibodies prevented leukocyte adhesion and transmigration in vitro and in vivo. Hence, these chimeric antibodies have the potential to be used as a new anti-inflammatory therapy.     

Pathways to care of first-admitted subjects with psychosis in South-Western France

BACKGROUND: A limited number of studies have assessed the pathways to care of patients with first-episode psychosis. The aim of the study was to describe the pathways to care of subjects with psychosis between onset of psychosis and first admission, and to examine the demographic and clinical factors influencing access to care. METHOD: Number and type of helping contacts since onset of first psychotic symptoms were assessed using multiple sources of information in 86 subjects with psychosis first-admitted in two hospitals of South-Western France. Characteristics independently associated with long delays between onset of symptoms and first helping contact, first treatment and first admission were explored using logistic regressions. RESULTS: Twelve per cent of subjects were first admitted without any previous helping contact. The patients were seen by a median of two helpers (maximum 7). For most patients (70%), the first helping contact was a health care professional, and the same proportion of patients had a first contact with a GP or a psychiatrist. The type of first contact was not predicted by demographic or clinical characteristics. Subjects with poor pre-morbid functioning or at-risk behaviour were more likely to have a delayed access to care. CONCLUSIONS: The delay in access to care may not be totally attributed to inadequate management by health professionals, but may be a characteristic of the disease itself, at least in part independent of the organization of the health system.     

No GIST-type c-kit gain of function mutations in neuroblastic tumours

AIMS: Neuroblastic tumours (NTs) have been shown to respond to imatinib treatment in vivo and in vitro, possibly via inactivating the c-kit receptor. The purpose of this study was to identify gastrointestinal stromal tumour (GIST)-type c-kit gene associated mutations in exons 9, 11, 13, and 17 in NTs to recognise a subset of tumours that would probably respond to imatinib treatment. METHODS: Expression of the c-kit protein was detected immunohistochemically in a total of 37 archival paraffin wax embedded NTs using polyclonal rabbit antihuman c-kit antibody. After immunohistochemistry, c-kit gene associated chromosomal mutations in all cases of NT were detected with denaturing high performance liquid chromatography (HPLC). RESULTS: Denaturing HLPC analysis did not reveal GIST-type mutations in four immunohistochemically detected c-kit positive or in 33 c-kit negative NTs. CONCLUSIONS: c-kit receptor expression and GIST-type c-kit gene mutations are rare events in NTs. Oncogenic activation of c-kit in NTs presumably differs from that of GISTs, which may influence their responsiveness to imatinib treatment. Whether c-kit has an essential role in the pathogenesis of NTs remains to be investigated.     

Measles virus inhibits lymphocyte proliferation in vitro by two different mechanisms.

We studied the effect of two different strains of measles virus (MV) on the lymphocyte blast transformation response. Infectious virus inhibited the proliferation response to PHA early during the culture when freshly isolated PBMC were stimulated. However, MV stimulated the proliferation of T cell lines early after infection and the inhibition was a late phenomenon associated with cell death. The early inhibition by the Edmonston strain of MV was shown to be monocyte-dependent by depletion studies with monoclonal antibodies. It could be partially explained by IFN-alpha production as the addition of anti-IFN-alpha antiserum to the cultures reversed the virus-induced inhibition and the addition of IFN reduced the response of uninfected PBMC. The late inhibition by the Edmonston strain was associated neither with monocytes nor with IFN-alpha but correlated with cell death in cultures. The inhibition by the Halle strain of MV was strong and associated with cell death already early after infection. The results demonstrate that MV inhibits lymphocyte proliferation by two different mechanisms and different virus strains vary both in the magnitude and mechanism of inhibition.