Mumps Virus

Virus-induced autoimmunity may play a causal role in autism. To examine the etiologic link of viruses in this brain disorder, we conducted a serologic study of measles virus, mumps virus, and rubella virus. Viral antibodies were measured by enzyme-linked immunosorbent assay in the serum of autistic children, normal children, and siblings of autistic children. The level of measles antibody, but not mumps or rubella antibodies, was significantly higher in autistic children as compared with normal children (P = 0.003) or siblings of autistic children (P ≤ 0.0001). Furthermore, immunoblotting of measles vaccine virus revealed that the antibody was directed against a protein of approximately 74 kd molecular weight. The antibody to this antigen was found in 83% of autistic children but not in normal children or siblings of autistic children. Thus autistic children have a hyperimmune response to measles virus, which in the absence of a wild type of measles infection might be a sign of an abnormal immune reaction to the vaccine strain or virus reactivation.

Mumps is a highly contagious human disease, characterized by lateral or bilateral nonsuppurative swelling of the parotid glands and neurological complications that can result in aseptic meningitis or encephalitis. A mumps vaccination program implemented since the 1960s reduced mumps incidence by more than 99% and kept the mumps case numbers as low as hundreds of cases per year in the United States before 2006. However, a large mumps outbreak occurred in vaccinated populations in 2006 and again in 2009 in the United States, raising concerns about the efficacy of the vaccination program. Previously, we have shown that clinical isolate-based recombinant mumps viruses lacking expression of either the V protein (rMuVΔV) or the SH protein (rMuVΔSH) are attenuated in a neurovirulence test using newborn rat brains (P. Xu et al., Virology 417:126-136, 2011, http://dx.doi.org/10.1016/j.virol.2011.05.003; P. Xu et al., J. Virol. 86:1768-1776, 2012, http://dx.doi.org/10.1128/JVI.06019-11) and may be good candidates for vaccine development. In this study, we examined immunity induced by rMuVΔSH and rMuVΔV in mice. Furthermore, we generated recombinant mumps viruses lacking expression of both the V protein and the SH protein (rMuVΔSHΔV). Analysis of rMuVΔSHΔV indicated that it was stable in tissue culture cell lines. Importantly, rMuVΔSHΔV was immunogenic in mice, indicating that it is a promising candidate for mumps vaccine development.

To evaluate the viral antibodies in new Iranian multiple sclerosis (MS) patients. In a cross-sectional study, sera from 61 MS patients and 60 healthy individuals were collected from January 2009 to March 2010 in the Immunology Department of Arak University of Medical Sciences, Arak, Iran, and examined for the presence of the anti-Epstein-Barr virus (EBV), human herpes virus 6 (HHV-6), measles, mumps, and para-influenza viruses IgG and IgM using an enzyme-linked immunosorbent assay or immunofluorescence. There were significant differences between the MS patients and the healthy individuals (controls) in the seroprevalence of anti-HHV-6 IgM (odds ratio [OR]=4.3, 95% confidence interval [CI]=2-9.3, p=0.001); anti-HHV-6 IgG (OR=2, 95% CI=1-4, p=0.04); anti-measles IgM (OR=3.2, 95% CI=1.5-6.9, p=0.002); and the anti-mumps IgM (OR=4.1, 95% CI=1.9-8.8, p=0.0001) and IgG (OR=9.5, 95% CI=3-29.6, p=0.0001). Almost all MS patients and the control individuals were negative to EBV and parainflue...

IgM detection is considered as the gold standard for mumps diagnosis. Currently, most cases in developed countries occur in highly vaccinated populations due to secondary vaccine failure. In these patients, pre-existing vaccine-induced antibodies are not able to neutralise the virus, but prevent the typical primary response, so that specific IgM is not always elicited. Consequently, acute infection has to be demonstrated by direct detection of the virus by viral isolation or genomic amplification. RT-PCR allows a diagnosis with the maximum sensitivity to be made and also forms the basis for genotype characterisation by sequencing the SH gene, according to WHO recommendations. However, none of the RT-PCR techniques properly evaluated for the diagnosis of acute mumps infection yields an amplification fragment useful for genotyping, and none of the amplification techniques described for genotyping has proved to be sensitive enough for diagnosis.Development of a RT-PCR for the mumps virus diagnosis and genotyping, properly evaluated in comparison with serological gold-standard technique.195 suspected mumps cases and six wild type MuV genotypes were studied.Our method was able to detect 0.001 TCID50 of mumps virus. Fifty-eight of these showed positive results, of which 54 (93.3%) showed mumps RNA in saliva, while only 20 (34.5%) had mumps IgM in serum. Genotypes G1, G2, H1, H2, D1 and C were identified in positive samples.The technique described could be a very useful tool for mumps surveillance, management and control.

Objective: To determine the proportion of Victorian primary school students protected against measles infection one year after the completion of the measles ’catch-up’ immunisation campaign of 1998 and to compare this with the proportion of year 9 and 10 (aged 14–16 years) students.Design & setting: Three-stage random cluster survey in Victorian primary and secondary schools.Main outcome measures: Proportion of primary and year 9 and 10 secondary school students protected against measles infection one year after the completion of the mass ’catch-up’ immunisation campaign. Secondary outcomes: the proportion of both primary and year 9 and 10 secondary school students protected against both mumps and rubella.Results: Of 1,037 Victorian primary and 2,357 years 9 and 10 secondary school students invited to participate in this study, 403 (39%) and 752 (32%) respectively provided a blood specimen for serological testing for antibodies against measles, mumps and rubella. 94.8% (95% confidence interval, 91.5, 96.9) of primary school and 93.1% (90.9, 94.8) of year 9 and 10 students were protected against measles infection.Conclusion: One year after the completion of the school-based measles ’catch-up’ immunisation campaign the level of protection in Victorian primary school aged students is sufficient to prevent the continuing circulation of measles virus within this age group. The proportion of year 9 and 10 secondary school students protected against measles is also probably sufficient to prevent continuing circulation of wild type virus in Victoria, even though this age group was not specifically targeted by the ’catch-up’ campaign.

Summary  A nationwide mumps-measles-rubella vaccination was introduced in 1982 in Finland to children aged 1.5 to 6 years and since then mumps has virtually disappeared in the country. We investigated whether this rapid epidemiological change had any impact on antibody activity against mumps virus in Type 1 (insulin-dependent) diabetic children or on the incidence of Type 1 diabetes in Finland. Two

In this study, we have developed a reverse transcription (RT)-nested polymerase chain reaction (n-PCR) for the detection of mumps virus RNA in cerebrospinal fluid (CSF) from patients with neurological infections. A specific 112-bp fragment was amplified by this method with primers from the nucleoprotein of the mumps virus genome. The mumps virus RT-n-PCR was capable of detecting 0.001 PFU/ml and 0.005 50% tissue culture infective dose/ml. This method was found to be specific, since no PCR product was detected in each of the CSF samples from patients with proven non-mumps virus-related meningitis or encephalitis. Mumps virus RNA was detected in all 18 CSF samples confirmed by culture to be infected with mumps virus. Positive PCR results were obtained for the CSF of 26 of 28 patients that were positive for signs of mumps virus infection (i.e., cultivable virus from urine or oropharyngeal samples or positivity for anti-mumps virus immunoglobulin M) but without cultivable virus in their...

SUMMARYWe undertook a national paediatric seroprevalence survey of measles, mumps and rubella (MMR) in Singapore to assess the impact of the national childhood immunization programme against these three diseases after introduction of the trivalent MMR vaccine in 1990. The survey involved 1200 residual sera of Singapore residents aged 1–17 years collected from two hospitals between 2008 and 2010. The overall prevalence of antibodies against measles, mumps and rubella was 83·1% [95% confidence interval (CI) 80·9–85·1], 71·8% (95% CI 69·1–74·2) and 88·5% (95% CI 86·6–90·2), respectively. For all three diseases, the lowest prevalence was in children aged 1 year (47·8–62·3%). The seroprevalence of the vaccinated children declined over time. The national MMR immunization programme is effective in raising the herd immunity of the childhood population, although certain age groups are more susceptible to infection, in particular, those who are not eligible for vaccination at age <15 months.

Mumps virus (MuV) remains an important pathogen worldwide, causing epidemic parotitis, orchitis, meningitis, and encephalitis. Here we show that MuV preferentially uses a trisaccharide containing α2,3-linked sialic acid in unbranched sugar chains as a receptor. Crystal structures of the MuV attachment protein hemagglutinin-neuraminidase (MuV-HN) alone and in complex with the α2,3-sialylated trisaccharide revealed that in addition to the interaction between the MuV-HN active site residues and sialic acid, other residues, including an aromatic residue, stabilize the third sugar of the trisaccharide. The importance of the aromatic residue and the third sugar in the MuV-HN−receptor interaction was confirmed by computational energy calculations, isothermal titration calorimetry studies, and glycan-binding assays. Furthermore, MuV-HN was found to bind more efficiently to unbranched α2,3-sialylated sugar chains compared with branched ones. Importantly, the strategically located aromatic re...

A high rate of post-vaccinal aseptic meningitis for Urabe AM9 mumps virus strain is well documented. This strain is composed of two virus variants differing at the nt 1081 (A/G) region in the hemagglutinin-neuraminidase (HN) gene. An association of HN-A1081 variant with neurovirulence has been proposed. In order to test for neurotropism we isolated the HN-A1081 and HN-G1081 virus variants from Urabe AM9 mumps virus vaccine. Sequential passages were performed in monkey kidney Vero cells and human neuroblastoma SH-SY5Y cells. Viral replication was determined by conventional and real-time RT-PCR. The results show that clone HN-A1081 can replicate efficiently in both cell types. However, a defective replication of clone HN-G1081, lacking its genetic marker, was observed after the third passage in neuroblastoma cells. Kinetics assays showed that clone HN-A1081 replicates faster than clone HN-G1081. Viral clones were also inoculated into the brains of newborn rats. Clone HN-A1081 replicated 14 times, while clone HN-G1081 merely duplicated its level over the initial inoculum. These results suggest that there is a selective replication of HN-A1081 mumps virus variants in cells of nervous origin.

Background The hemagglutinin-neuraminidase (HN) protein is the major antigenic determinant of the Mumps virus (MuV) and plays an important role in the viral infectious cycle through its hemagglutination/hemadsorption (HA/HD) and neuraminidase (NA) activities. Objective: analyze the biological and immunological properties of a polypeptide derived from a highly conserved region of the HN ectodomain. Methods: a highly conserved region of the HN gene among several MuV genotypes was chosen to be cloned in a eukaryotic expression vector. The pcDNAHN176-construct was transfected into Vero cells and RNA expression was detected by RT-PCR, while the corresponding polypeptide was detected by immunofluorescence and immunochemistry techniques. The HD and NA activities were also measured. The immunogenic properties of the construct were evaluated using two systems: rabbit immunization to obtain sera for detection of the HN protein and neutralization of MuV infection, and hamster immunization to evaluate protection against MuV infection. Results A 567 nucleotide region from the HN gene was amplified and cloned into the plasmid pcDNA3.1. Vero cells transfected with the construct expressed a polypeptide that was recognized by a MuV-hyperimmune serum. The construct-transfected cells showed HD and NA activities. Sera from immunized rabbits in vitro neutralized two different MuV genotypes and also detected both the HN protein and the HN176 polypeptide by western blot. Hamsters immunized with the pcDNAHN176-construct and challenged with MuV showed a mild viral infection in comparison to non-immunized animals, and Th1 and Th2 cytokines were detected in them. Conclusions The pcDNAHN176-construct was capable of expressing a polypeptide in Vero cells that was identified by a hyperimmune serum anti Mumps virus, and these cells showed the HD and NA activities of the complete MuV HN protein. The construct also elicited a specific immune response against MuV infection in hamsters.

Waning immunity to mumps after one or two doses of the measles, mumps and rubella (MMR) vaccine has been described. Using a human peripheral blood lymphocyte (PBL)–severe combined immunodeficiency (SCID) mouse model, MMR vaccine recipients with undetectable and high antibody titres against mumps were compared for the presence of circulating mumps-specific memory B cells. Peripheral blood mononuclear cells (PBMC) from six donors (three subjects with undetectable and three with high antibody titres against mumps) were injected into the spleens of non-obese diabetic (NOD)-SCID mice (three mice per subject). Mice were pretreated with TMβ1 and total body irradiation to improve engraftment. In vivo production of human antibodies against mumps was evaluated in mouse plasma on days 7, 10 and 13 with a commercial enzyme-linked immunosorbent assay (ELISA), functional reduction neutralization test. Three donors had mumps antibody titres below the detection limit (titre < 230) and three had high antibody titres (range 5700–7300). None of the mice injected with PBMC from subjects with undetectable antibody titres showed detectable human antibody titres, despite the presence of cell-mediated immunity in two of the three donors. Seven out of nine mice injected with PBMC from subjects with high antibody titres acquired detectable antibody titres for mumps in their plasma. PBMC from vaccinees without detectable serum antibodies against mumps virus were unable to induce secretion of anti-mumps antibodies in the blood of recipient mice, whereas PBMC from vaccinees with high antibody titres were able to do so. This observation suggests that the frequency of mumps-specific memory B cells is very low in vaccinees with undetectable antibody titres. These individuals may therefore be at risk of developing mumps disease upon encounter with wild-type virus.

Mumps virus (MuV) is a highly contagious pathogen, and despite extensive vaccination campaigns, outbreaks continue to occur worldwide. The virus has a negative-sense, single-stranded RNA genome that is encapsidated by the nucleocapsid protein (N) to form the nucleocapsid (NC). NC serves as the template for both transcription and replication. In this paper we solved an 18-Å-resolution structure of the authentic MuV NC using cryo-electron microscopy. We also observed the effects of phosphoprotein (P) binding on the MuV NC structure. The N-terminal domain of P (PNTD) has been shown to bind NC and appeared to induce uncoiling of the helical NC. Additionally, we solved a 25-Å-resolution structure of the authentic MuV NC bound with the C-terminal domain of P (PCTD). The location of the encapsidated viral genomic RNA was defined by modeling crystal structures of homologous negative strand RNA virus Ns in NC. Both the N-terminal and C-terminal domains of MuV P bind NC to participate in acce...