Mumps virus infection disrupts blood-testis barrier through the induction of TNF-α in Sertoli cells.

Mumps virus (MuV) has high tropism to the testis and may lead to male infertility. Sertoli cells are the major targets of MuV infection. However, the mechanisms by which MuV infection impairs male fertility and Sertoli cell function remain unclear. The present study elucidated the effect of MuV infection on the blood-testis barrier (BTB). The transepithelial electrical resistance of MuV-infected mouse Sertoli cells was monitored, and the expression of major proteins of the BTB was examined. We demonstrated that MuV infection disrupted the BTB by reducing the levels of occludin and zonula occludens 1. Sertoli cells derived from Tlr2-/- and Tnfa-/- mice were analyzed for mediating MuV-induced impairment. TLR2-mediated TNF-α production by Sertoli cells in response to MuV infection impaired BTB integrity. MuV-impaired BTB was not observed in Tlr2-/- and Tnfa-/- Sertoli cells. Moreover, an inhibitor of TNF-α, pomalidomide, prevents the disruption of BTB in response to MuV infection. FITC-labeled biotin tracing assay confirmed that BTB permeability and spermatogenesis were transiently impaired by MuV infection in vivo. These findings suggest that the disruption of the BTB could be one of the mechanisms underlying MuV-impaired male fertility, in which TNF-α could play a critical role.-Wu, H., Jiang, X., Gao, Y., Liu, W., Wang, F., Gong, M., Chen, R., Yu, X., Zhang, W., Gao, B., Song, C., Han, D. Mumps virus infection disrupts blood-testis barrier through the induction of TNF-α in Sertoli cells.

C-X-C motif chemokine ligand 10 produced by mouse Sertoli cells in response to mumps virus infection induces male germ cell apoptosis.

Mumps virus (MuV) infection usually results in germ cell degeneration in the testis, which is an etiological factor for male infertility. However, the mechanisms by which MuV infection damages male germ cells remain unclear. The present study showed that C-X-C motif chemokine ligand 10 (CXCL10) is produced by mouse Sertoli cells in response to MuV infection, which induces germ cell apoptosis through the activation of caspase-3. CXC chemokine receptor 3 (CXCR3), a functional receptor of CXCL10, is constitutively expressed in male germ cells. Neutralizing antibodies against CXCR3 and an inhibitor of caspase-3 activation significantly inhibited CXCL10-induced male germ cell apoptosis. Furthermore, the tumor necrosis factor-α (TNF-α) upregulated CXCL10 production in Sertoli cells after MuV infection. The knockout of either CXCL10 or TNF-α reduced germ cell apoptosis in the co-cultures of germ cells and Sertoli cells in response to MuV infection. Local injection of MuV into the testes of mice confirmed the involvement of CXCL10 in germ cell apoptosis in vivo. These results provide novel insights into MuV-induced germ cell apoptosis in the testis.

Establishing a small animal model for evaluating protective immunity against mumps virus.

Although mumps vaccines have been used for several decades, protective immune correlates have not been defined. Recently, mumps outbreaks have occurred in vaccinated populations. To better understand the causes of the outbreaks and to develop means to control outbreaks in mumps vaccine immunized populations, defining protective immune correlates will be critical. Unfortunately, no small animal model for assessing mumps immunity exists. In this study, we evaluated use of type I interferon (IFN) alpha/beta receptor knockout mice (IFN-α/ßR-/-) for such a model. We found these mice to be susceptible to mumps virus administered intranasally and intracranially. Passive transfer of purified IgG from immunized mice protected naïve mice from mumps virus infection, confirming the role of antibody in protection and demonstrating the potential for this model to evaluate mumps immunity.

Mumps virus-induced innate immune responses in mouse Sertoli and Leydig cells.

Mumps virus (MuV) infection frequently causes orchitis and impairs male fertility. However, the mechanisms underlying the innate immune responses to MuV infection in the testis have yet to be investigated. This study showed that MuV induced innate immune responses in mouse Sertoli and Leydig cells through TLR2 and retinoic acid-inducible gene I (RIG-I) signaling, which result in the production of proinflammatory cytokines and chemokines, including TNF-α, IL-6, MCP-1, CXCL10, and type 1 interferons (IFN-α and IFN-ß). By contrast, MuV did not induce the cytokine production in male germ cells. In response to MuV infection, Sertoli cells produced higher levels of proinflammatory cytokines and chemokines but lower levels of type 1 IFNs than Leydig cells did. The MuV-induced cytokine production by Sertoli and Leydig cells was significantly reduced by the knockout of TLR2 or the knockdown of RIG-I signaling. The local injection of MuV into the testis triggered the testicular innate immune responses in vivo. Moreover, MuV infection suppressed testosterone synthesis by Leydig cells. This is the first study examining the innate immune responses to MuV infection in testicular cells. The results provide novel insights into the mechanisms underlying the MuV-induced innate immune responses in the testis.

Inhibition of virus-like particle release of Sendai virus and Nipah virus, but not that of mumps virus, by tetherin/CD317/BST-2.

Tetherin (also known as BST-2 or CD317) has recently been identified as a potent IFN-induced anti-viral protein that inhibits the release of diverse enveloped virus particles from infected cells. The anti-viral activity of tetherin on a number of enveloped viruses, including retroviruses, filoviruses and arenaviruses, has been examined. Here, we show that tetherin is also capable of blocking the release of virus-like particles (VLPs) driven by the matrix protein of Sendai virus. Together with inhibition of Nipah virus VLP release by tetherin, these results indicate that paramyxoviruses are to be added to the list of viruses that are susceptible to tetherin inhibition. Tetherin co-localized with Nipah virus matrix proteins and accumulated in cells, indicating that it is present at, or recruited to, sites of particle assembly. It should be noted, however, that tetherin was not effective against the release of paramyxovirus mumps VLPs, indicating that certain enveloped viruses may not be sensitive to tetherin activity.

Experimental mumps virus-induced hydrocephalus: viral neurotropism and neuronal maturity.

In order to elucidate the relationship between virus neurotropism and neuronal maturity, two experiments were performed. First, mumps virus infectivity was compared among the different developmental stages of hamster brains inoculated with mumps virus by examining the immunohistochemical distribution of mumps virus antigen. Second, brain lesions resulting from mumps virus infection during the period of neuronal migration were histologically and ultrastructurally analyzed. Three groups of Syrian hamsters, Group E12 (fetuses on the 12th day of gestation), and Groups P2 and P30 (2 and 30 days old, respectively), were injected with mumps virus intraplacentally or intracerebrally. In Group P30, mumps virus antigen was observed specifically in ependymal cells and the choroid plexus. In addition to these areas, in Group P2, some neurons in layers II and III of the cerebral cortex also showed virus antigen immunoreactivity. In Group E12, mumps virus antigen accumulated primarily in the neuroepithelial cells within the ventricular zone. Neither specific intranuclear changes related to viral replication nor the formation of complete virions and nucleocapsids was observed. We conclude that mumps virus neurotropism to hamster brains is dependent on the degree of neuronal maturity and that mumps virus can induce an abortive infection and resultant neuronal cell necrosis in the immature developing hamster brain.

Reduction of voltage-dependent calcium currents in mumps virus-infected cultures of rat hippocampal neurons.

The effects of a mumps virus infection on functional properties of embryonic hippocampal neurons in culture were analysed with special emphasis on voltage-dependent Ca2+ channels. Cultures with higher or lower density of glial cells (not treated or treated with mitotic inhibitor, respectively) were infected with the relatively non-cytolytic RW strain of mumps virus and currents were recorded from neurons using whole cell voltage clamp. More than 65% of neurons and glial cells contained viral antigens 1-2 days post infection (p.i.). Glial cells remained infected 6-7 days p.i., while the ratio of infected versus uninfected neurons, especially in cultures with higher glial cell density, was reduced. In both infected and uninfected cultures the somal voltage-dependent Ca2+ currents were stronger in cultures with a higher glial cell density, which indicates that these currents are influenced by glial cells. Introduction of the virus into cultures caused a selective decrease in inward Ca2+ currents, which was most marked at days 6-7 p.i., and which included both infected and unifected neurons. Spontaneous synaptic currents and other ion channel conductances appeared normal in the infected cultures. Dantrolene, which inhibits release of Ca2+ from intracellular stores, decreased the neurons that died during the infection. Taken together the results show that a mumps viral infection can selectively alter the number of function of somal voltage dependent Ca2+ channels in immature hippocampal neurons and that this may reflect a disturbed glia-nerve cell interaction.

Two-dimensional electrophoretic patterns of acute-phase human serum proteins in the course of bacterial and viral diseases.

Acute-phase serum proteins were analyzed by two-dimensional electrophoresis with isoelectric focusing in 3-10 immobilized pH gradients. Most spots were identified by reference to the plasma map in the SWISS-2DPAGE database. Serum amyloid A protein spots were identified by immunoblotting with specific antiserum and by matching determined with predicted values of electrophoretic parameters. Changes in the concentrations of alpha 1-antitrypsin, leucine-rich glycoprotein, haptoglobin, serum retinol-binding protein and transthyretin were quantitated by densitometry of silver-stained gels. Electrophoretic patterns from 18 patients with bacterial diseases and 16 patients with viral diseases were compared. The incidence of serum amyloid A protein spots was 18/18 in bacterial diseases and 6/16 in viral diseases. As the the other reactants studied, variations were simultaneous in bacterial disease and tended to be staggered in viral diseases.

Mumps and Coxsackie B3 virus infection of human fetal pancreatic islet-like cell clusters.

Islet-like cell clusters (ICCs) prepared from human fetal pancreases were infected with mumps or coxsackie B3 virus. Double-labeled antibody technique showed that the viruses infected both insulin-secreting and other pancreatic cells and that secretion of immunoreactive insulin into the culture medium of the mumps virus-infected cells had already ceased on day 7. The mumps virus-infected ICC clusters produced virus for 14 days, and the mumps virus antigen was detected in the ICCs through the whole 22-day observation period. The coxsackie B3 virus-infected ICCs contained cells highly positive for viral antigen during the first 2 days after infection, and the infectious virus was detected in the culture medium for 22 days. This in vitro model indicates that mumps and coxsackie B3 viruses infect human fetal pancreatic endocrine cells and are able to alter beta-cell function. Coxsackie B3 virus infection in ICCs is lytical and seems to lead to rapid cell destruction, but long-lasting, restricted mumps virus infection in human fetal pancreatic ICCs offers an interesting model to study the effects of viral infection in the endocrine pancreas and beta cell.

Metabolic, hormonal, and immunological alterations in subjects with antecedent mumps infection.

Since mumps virus seems to be one of the most likely candidates in viral etiology of insulin-dependent diabetes (IDDM) we studied the possible relationship of glucose tolerance (75 g oGTT), beta cell function, diabetes associated HLA antigens, haptoglobin phenotype, islet cell antibodies (ICA) and islet cell surface antibodies (ICSA) in 125 subjects with antecedent mumps infection. Impaired glucose tolerance (IGT) was diagnosed in 3.2% (n = 4) but onset of diabetes did not appear within 14 months after mumps infection. There was no relationship between glucose tolerance and complications of antecedent mumps infection (e.g. pancreatitis, meningitis, orchitis). The prevalence rate of ICA was 76%. ICSA were detectable in about 36% of children and 62% of the adults tested (p less than 0.01). There was no relationship between ICA/ICSA and diabetes-associated HLA antigens, haptoglobin phenotype or beta cell function (fasting C-peptide and insulin response to 75 g oGTT). However, adults with circulating ICA were characterized by a significantly lower insulin response to glucose. Fifty two "risk" subjects characterized by IGT, diabetes associated HLA antigen(s), ICA or ICSA either alone or combined were studied again 26 months after mumps infection. No symptomatic diabetes appeared and IGT was diagnosed in one case only. ICA and ICSA persisted in more than 50% of subjects in whom ICA or ICSA were present 14 months after mumps infection. Since the used immunological techniques do not clearly distinguish organ-specific from non-organ-specific antibodies the results must be interpreted with caution. To summarize, the preliminary results do not support a close temporal relationship between mumps infection and the onset of IDDM. The pathogenetic role of mumps virus and ICA/ICSA and their possible relation to a slow progressive beta cell destruction has still to be determined.

[Metabolism of various biogenic amines in acute viral neuroinfections]. / Ob obmene nekotorykh biogennykh aminov pri ostrykh virusnykh neiroinfektsiiakh.

The metabolism of biogenic amines was examined in 62 patients with various acute viral neuroinfections. The control group consisted of 57 persons. Depending on the process character and disease period variations of the levels of serotonin, 5-hydroxyindolylacetic acid, coeruloplasmin and histamine were discovered. A comparison of the results obtained with the clinical course of the diseases revealed a certain correlation, especially in patients with acute meningoencephalitis.

Viral antibodies in oligoclonal and polyclonal IgG synthesized within the central nervous system over the course of mumps meningitis.

The occurrence of viral antibodies in relation to IgG separated by thin-layer polyacrylamide gel isoelectric focusing was studied in CSF and serum from 24 patients with mumps meningitis by immunofixation with viral antigens and autoradiography. Eleven of the patients displayed on the autoradiograms evidence of locally in the central nervous system synthesized mumps virus antibodies which were related to oligoclonal IgG bands in all 5 patients who displayed this CSF abnormality, otherwise to polyclonal IgG bands. Local synthesis of mumps virus antibodies was detectable in 43% of specimens obtained 1-13 days after onset, and in 75% obtained 27-47 days after onset. Only one patient displayed local synthesis of antibodies to other viruses (measles and herpes simplex) which could then be traced to polyclonal IgG bands.

Lipids in human testis.

The lipid composition of human testis intesticular and post-testicular causes of infertility was studied. The testicular causes of infertility was represented by patients with adult seminiferous tubule failure and Klinefelter's syndrome. The post-testicular causes of infertility were represented by patients with obstruction of efferent ducts of testes. A significant accumulation of total testicular lipids was observed in both causes of infertility. A marked increase in free and esterified cholesterol, monoglycerides and triglycerides caused the accumulation of total testicular lipids in testicular causes of infertility. The accumulation of these lipids was more pronounced in Klinefelter's syndrome compared to adult seminiferous tubule failure. In post-testicular causes of infertility, a vary marked increase in phospholipids along with cholesterol fractions and glycerides led to the accumulation of total testicular lipids. The significant increase in total phospholipids caused by the increases in phosphatidylcholine and phosphatidylethanolamine differentiates post-testicular causes of infertility from testicular causes in which phospholipid classes remained unaffected. Thus, changes in hormonal mileu due to pathological conditions also lead to marked alterations in testicular lipids.