William W. Hall

Evidence for lack of synthesis of the M polypeptide of measles virus in brain cells in subacute sclerosing panencephalitis

Abstract The synthesis of measles virus polypeptides in cells in their fifth passage after removal from the brain of a patient with subacute sclerosing panencephalitis (SSPE) has been investigated using immunoprecipitation techniques. Although the other major virion polypeptides were found, synthesis of the M polypeptide was not detected. High titers of antibodies to the other virion proteins were found in the cerebrospinal fluid, as well as the serum, of a patient with SSPE, but only a trace of antibody to the M polypeptide was found at the lowest dilutions. These results, and the earlier finding of the lack of antibody to M in the sera of many patients with SSPE, support the previous suggestion that there is decreased synthesis of the M polypeptide in the cells of the brain in patients with SSPE.

The polypeptides of canine distemper virus: synthesis in infected cells and relatedness to the polypeptides of other morbilliviruses.

Abstract The biochemical and immunological properties of the polypeptides of canine distemper virus (CDV), their synthesis and processing in infected cells, and their relatedness to the polypeptides of other morbilliviruses have been studied. CDV virions contain six major polypeptides which are analogous to those of measles virus (MV). These polypeptides with their estimated molecular weights (mr) are: L (200,000); H (76,000); P (66,000); NP (58,000); F (62,000), which consists of two disulfide-linked polypeptides, F1 (40,000) and F2 (23,000); and M (34,000). The H, F1, and F2 polypeptides of CDV are glycosylated; the presence of carbohydrate on F1 is in contrast to its absence on the F1 of MV. The CDV F2 has a larger apparent Mr than the MV F2 (23,000 vs 12,000). The NP and P polypeptides of CDV are phosphorylated, and in pulse-chase experiments in CDV-labe;ed cells the P polypeptide was rapidly lost. In addition to the structural polypeptides, a putative nonstructural protein, NS (Mr ∼ 18,000), was found in CDV-infected cells. The polypeptide also turned over rapidly in pulse-chase experiments. The immunological relatedness of the polypeptides of MV and CDV and of two other morbilliviruses, rinderpest (RV) and a bovine encephalitis virus (107) was shown by immuno-precipitation of the viral polypeptides from CDV- and MV-infected cells with antisera against each of the four viruses. The only failure to exhibit reciprocal reactivity between CDV and MV was found with the H polypeptides, where only a one-way cross was found, i.e., MV antiserum precipitated all of the CDV polypeptides, whereas CDV antiserum precipitated all of the MV polypeptides except H. RV antiserum resembled that of MV; it precipitated all of the polypeptides of both MV and CDV, whereas 107 antiserum, like that of CDV, precipitated all of the CDV polypeptides and all of the MV polypeptides except H. These results indicate that these four morbilliviruses with different host ranges are antigenically closely related, with MV apparently more closely related to RV, and CDV to 107 virus. In spite of their antigenic similarities, the individual polypeptides of CDV and MV could be easily distinguished by peptide mapping. Some similarities were found in the internal polypeptides P, NP, and M, but very little in the surface glycoproteins, H and F1.

A rat model of Parkinson's disease induced by Japanese encephalitis virus.

In Fischer rats infected with Japanese encephalitis virus (JEV) at 13 days after birth and sacrificed 12 weeks later, the major pathological changes resembled those found in Parkinsons disease. Specifically there was neuronal loss with gliosis which was confined mainly to the zona compacta of the substantia nigra, with a notable absence of lesions in the cerebral cortex and cerebellum. Changes were bilateral being most severe in the central part of the zona compacta. Immunohistochemical studies with anti-tyrosine hydroxylase (TH) demonstrated that the number of TH-positive neurons was significantly decreased in the substantia nigra compared to controls, while comparable numbers of TH-positive neurons were found in the basal ganglia in both JEV-treated rats and age-matched controls. JEV-infected rats showed marked bradykinesia, with significant behavioral improvement being observed following administration of L-DOPA. Immunohistochemical studies failed to detect JEV antigens in any region of the rat brain and the JEV genome was undetectable in the substantia nigra and the cerebral cortex using the reverse transcription-polymerase chain reaction (RT-PCR). The findings suggest that JEV infection of rats under the conditions described may serve as a model of virus induced Parkinsons Disease.

Immunological evidence for the synthesis of all canine distemper virus polypeptides in chronic neurological diseases in dogs. Chronic distemper and old dog encephalitis differ from SSPE in man.

Abstract Immunoprecipitation of the polypeptides of canine distemper virus (CDV) from lysates of infected cells has revealed that the serum and cerebrospinal fluid (CSF) of dogs with chronic distemper and old dog encephalitis contain high levels of antibody to all the viral structural polypeptides, indicating that all of these polypeptides are being synthesized in the dogs. These findings, and the fact that infectious virus has been isolated from explants of brain tissue without cocultivation techniques, differ from those with measles virus in subacute sclerosing panencephalitis (SSPE) in which there is a lack of antibody to the virus membrane (M) protein and cocultivation of brain explants with permissive cells is required for virus isolation. These results indicate that CDV undergoes complete replication in the brain in the persistent infection resulting in chronic neurological disease, in contrast to the situation with measles virus in SSPE in which replication appears to be abortive.

Anti-viral and immunomodulatory effects of interferon-α on cultured lymphocytes from patients with human T lymphotropic virus type I-associated myelopathy (HAM/TSP)

In contrast to therapeutic benefits of interferon-alpha (IFN-alpha) in patients with human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP), little is known about the mechanisms underlying its clinical efficacy. To investigate the anti-viral and/or immunomodulatory properties of IFN-alpha in HTLV-I infection, the effects of IFN-alpha on HTLV-I-induced in vitro phenomena were evaluated. In vitro activation of HTLV-I in fractionated CD4+ T lymphocyte-rich cells (CD4+ cells) could be demonstrated by increased thymidine incorporation into the cells, detection of proviral HTLV-I and viral RNA, and by assays of reverse transcriptase activities in culture supernatants. T cell immune responses were evaluated by thymidine incorporation into CD8+ T lymphocyte-rich cells (CD8+ cells) responding to cultured and irradiated autologous CD4+ cells possessing HTLV-I antigens. It could be shown that IFN-alpha suppressed both the in vitro activation of HTLV-I and the CD8+ cell response. Moreover, 1 day supplementation of IFN-alpha as a pretreatment was sufficient for the induction of these properties. These findings, together with the clinical efficacy of IFN-alpha administration in patients with HAM/TSP, support the view that viral activation and T cell responses are critical components in the pathogenic processes involved in HAM/TSP.

Induction of chronic neurologic disease in mice with canine distemper virus

The capacity of a mouse-adapted strain of canine distemper virus (CDV) to induce central nervous system (CNS) disease in weanling mice was investigated. Lethality of infection was found to be mouse-strain-dependent. In sensitive strains, an acute meningoencephalomyelitis developed. Brain tissue from acutely ill animals demonstrated numerous foci of viral antigen, and extracts yielded infectious virus. Mice of resistant strains, notably the SJL strain, survived the effects of acute infection, appeared well for several weeks, and then began to develop signs of subacute CNS disease. Preliminary histopathologic examination of brain and cord from acutely ill animals revealed prominent perivascular mononuclear cell infiltrates, mononuclear cell meningitis, and gliosis. These features were also found in the subacute disease, where, however, the lesions were less severe. Also, in the latter, virus antigen could not be demonstrated. The results indicate that CDV infection of mice may provide a promising model system for the study of virus-induced chronic CNS disease.

In vitro virus propagation and high cellular responsiveness to the infected cells in patients with HTLV-I-associated myelopathy (HAM/TSP)

The reasons for the development of HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in certain infected individuals remain poorly understood, but the susceptibility should involve both viral factors and host conditions. To assess simultaneously both virus-induced activation of infected cells and the cellular response to virus producing cells, an analysis of fractionated peripheral blood lymphocytes obtained from patients with HAM/TSP (n = 15) were compared with those of asymptomatic HTLV-I carriers (n = 9) in an age-matched manner. The in vitro propagation of HTLV-I infection was evaluated as the spontaneous thymidine incorporation into CD4+ cells, and proliferative response of CD8+ cells against cultured and irradiated autologous CD4+ cells was employed to analyze the HTLV-I-induced cellular response. The comparative analysis using these two parameters demonstrated that HAM/TSP patients were characterized by the concomitance of a high inducibility of HTLV-I propagation and a high cellular responsiveness against HTLV-I as compared with asymptomatic HTLV-I carriers, suggesting the involvement of both of these factors in disease susceptibility. In addition, the coupled evaluation of these two in vitro phenomena may offer a better diagnostic hallmark for HTLV-I seropositive myelopathy cases with other known cause of myelopathy.

Detection of an HTLV‐II‐Seropositive Blood Donor in Japan

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A Novel BSE screening kit with simplified preparation method for EIA

Introduction In Japan, all slaughtered and deceased bovine materials are tested for BSE infection. The primary screening test is undertaken by the meat inspection office or live stock hygiene service center in each prefecture. In these circumstances, BSE kits adapted for relatively small number of samples are required. Here we describe the development of a neŵ BSE screening system, which has simpler and safer protocol for sample preparation steps for EIA. This assay system has been named the NippIBL BSE Assay system.