Monoclonal antibodies specific for Hantaan virus

Six hybridoma cell line producing monoclonal antibodies to Hantaan virus were established by fusion of NS-1 mouse myeloma cells with spleen cells of mice immunized with Hantaan virus strain 76-118. The specificity of these monoclonal antibodies was established by immunoblotting analysis and immunofluorescence. Five of the clones reacted with antigens on the cell surface and in the cytoplasm, and one clone reacted with a determinant expressed only in the cytoplasm of the infected cells. Two of the clones produced antibodies that reacted with a Mr 50,000 polypeptide in virus-infected cellular extracts and purified virus preparations. The monoclonal antibodies were used to examine the antigenic relationship among Hantaan virus strains and between Hantaan virus and Prospect Hill virus and the virus of nephropathia epidemica. Three antibodies were capable of distinguishing between the Lee strain and the 760-118 strain of Hantaan virus and three additional antibodies reacted with determinants shared by both virus strains. None of the six reacted with Prospect Hill virus or the virus of nephropathia epidemica.

Immune function among normal Guamanians of different age

To determine if immune function differed in normal Guamanian Chamorros at various ages we measured the percentage and total numbers of lymphocytes and T-lymphocytes, their response to phytohemagglutinin (PHA), and serum levels of immunoglobulin A, G, and M in subjects 20 to 83 years of age. Regression analysis showed highly significant negative correlations for total lymphocytes and T-cells with age and a less significant negative correlation for PHA response with age in this population. Serum IgA levels increased with age, IgM levels declined, and IgG levels were unchanged. These findings are similar to, but less marked than, immunologic aberrations previously observed in Guamanians with amyotrophic lateral sclerosis or Parkinsonism-dementia. The occurrence of prominent differences in immune functions between younger and older individuals in a population where neurofibrillary degeneration in brain occurs at an early age and neurodegenerative and other age-related diseases are highly prevalent suggests the possibility that immunity and age-associated degenerative disease may be linked etiologically in this population.

Syndromes of amyotrophic lateral sclerosis and dementia: relation to transmissible Creutzfeldt-Jakob disease

A review of over 2,000 cases of Creutzfeldt-Jakob disease and related disorders in the literature and our own files yielded 231 cases of dementia with early lower motor neuron signs. The clinical-pathological profiles of the 231 cases were distinctly different from those of cases of transmissible Creutzfeldt-Jakob disease: the patients had a longer illness, and their brains lacked the typical spongiform change. Brain tissue from 33 of these patients has been inoculated intracerebrally into nonhuman primates, but only 2 atypical cases transmitted a spongiform encephalopathy; 23 have been incubating from three to twelve years and can be considered negative transmission experiments. The findings suggest that most cases of dementia associated with early amyotrophy are more closely related to classic amyotrophic lateral sclerosis than to transmissible Creutzfeldt-Jakob disease and do not deserve the label of "amyotrophic Creutzfeldt-Jakob disease." When lower motor neuron involvement occurs in transmissible Creutzfeldt-Jakob disease, it is usually late and accompanied by signs of a more fulminant cerebral and cerebellar involvement.

Search for a red cell enzyme or serum protein marker in amyotrophic lateral sclerosis and parkinsonism-dementia of Guam

Frequency distributions were determined for 24 red cell enzyme and four serum protein systems, in an attempt to identify a genetic marker associated with either amyotrophic lateral sclerosis (ALS) or parkinsonism-dementia (PD), two progressive and fatal neurological disorders of unknown cause found with unusually high incidence among the Chamorros of Guam and the Northern Mariana Islands. No striking associations were identified between either disorder and any of the gene markers tested. Thus, no genetic cause is known for either disease; local environmental factors are most likely involved in pathogenesis.

The pathogenesis of transmissible spongiform encephalopathy: an ultrastructural study

The brains of 9 spider monkeys, inoculated intracerebrally with brain suspension from kuru patients and of 3 normal control monkeys have been studied. All the animals were killed by perfusion with fixative, 8 during early incubation (ranging from 2 to 40 weeks) when healthy and free from neurological signs, one after 122 weeks when the disease was fully established. The most striking feature seen in every brain between the incubation times of 4 and 40 weeks was the formation of multilaminated membranes (ACPMs). These affected stretches of two apposed, mostly neuronal, plasma membranes over variable distances and created the impression of complex ribbon-or cord-like junctions. Their number varied with the length of incubation, reaching a peak at 13 weeks and declining thereafter. ACPMs were found throughout the grey matter, but they were most numerous in phylogenetically older regions of the brain, regions which also show the severest lesions in human kuru. It is suggested that ACPMs are initially due to an excessive synthesis of some membrane constituent by the perikaryon and various possibilities for their genesis are discussed. The hypothesis is advanced that they may be due to the reactivation of embryonic growth mechanisms and represent abortive junctions which, being formed in mature neurons, take a rather bizarre shape. Other changes such as the formation of somatic spines, an excessive number of dendritic spines including a high proportion with long tortuous necks, and the presence of binucleated neurons and numerous growth cones, point to the similarly immature pattern and would support this hypothesis. The material provided ample evidence that ACPMs, which can occupy as much as 26 per cent of a dendritic surface, give rise to intracytoplasmic vacuoles, which may therefore be regarded as secondary to a primary change in the permeability of the plasma membrane at the site of ACPMs. Individual single vacuoles could often build up into complex soap-bubble-like arrays, which were interpreted as the ultrastructural equivalent of histological status spongiosus. There is some evidence that the development of status spongiosus in other transmissible spongiform encephalopathies follows the same pattern.

Alzheimer's disease and transmissible virus dementia (Creutzfeldt-Jakob disease)

Ample justification exists on clinical, pathologic, and biologic grounds for considering a similar pathogenesis for AD and the spongiform virus encephalopathies. However, the crux of the comparison rests squarely on results of attempts to transmit AD to experimental animals, and these results have not as yet validated a common etiology. Investigations of the biologic similarities between AD and the spongiform virus encephalopathies proceed in several laboratories, and our own observation of inoculated animals will be continued in the hope that incubation periods for AD may be even longer than those of CJD.

Heterogeneic autoantibody against neurofilament protein in the sera of animals with experimental kuru and Creutzfeldt-Jakob disease and natural scrapie infection

Heterogeneic autoantibodies against axonal neurofilament proteins of mature mouse neurons grown in vitro were detected by the indirect immunofluorescence technique in 12.7% (9 of 71) of the sera from nonhuman primates infected with kuru, in 14.5% (17 of 117) and 4% (1 of 25), respectively, of the sera from nonhuman primates and laboratory rodents infected with Creutzfeldt-Jakob disease, and in 35% (7 of 20) of the sera from sheep naturally infected with scrapie. Autoantibody titers ranged from 1:16 to 1:512 in Creutzfeldt-Jakob disease-infected animals, 1:32 to 1:512 in kuru-infected animals, and 1:64 to 1:1,024 in sheep with natural scrapie. The sera from 11 monkeys and 17 hamsters infected with scrapie and from 19 chimpanzees inoculated with brain tissues from humans with other neurological diseases did not contain autoantibodies. Of the 41 chimpanzees with Creutzfeldt-Jakob disease, 6 had autoantibodies against neurofilament proteins before experimental inoculation, whereas 6 others developed autoantibodies after inoculation, 4 developed autoantibodies during the asymptomatic phase, and 2 developed autoantibodies during the terminal clinical phase. Of the 48 chimpanzees with kuru, 2 had autoantibodies before inoculation, 6 developed autoantibodies after inoculation, 3 developed autoantibodies during the asymptomatic phase, and 3 developed autoantibodies during the terminal clinical phase. Among the normal nonhuman primate controls, 4.6% (9 of 195) had autoantibodies. In contrast, no autoantibodies were detected in 49 control rodents and 13 control sheep. The increased incidence of autoantibodies against neurofilament proteins in animals with kuru, Creutzfeldt-Jakob disease, and scrapie constitutes the first evidence of an immunological reaction in this group of atypical infections caused by unconventional viruses and suggests that neurofilaments may be involved in pathogenesis.

Intraneuronal aluminum accumulation in amyotrophic lateral sclerosis and Parkinsonism-dementia of Guam

Scanning electron microscopy with energy-dispersive x-ray spectrometry was used to analyze the elemental content of neurofibrillary tangle (NFT)-bearing and NFT-free neurons within the Sommer's sector (H1 region) of the hippocampus in Guamanian Chamorros with amyotrophic lateral sclerosis and parkinsonism-dementia and in neurologically normal controls. Preliminary data indicate prominent accumulation of aluminum within the nuclear region and perikaryal cytoplasm of NFT-bearing hippocampal neurons, regardless of the underlying neurological diagnosis. These findings further extend the association between intraneuronal aluminum and NFT formation and support the hypothesis that environmental factors are related to the neurodegenerative changes seen in the Chamorro population.

Evidence for an unconventional virus in mouse-adapted Creutzfeldt-Jakob disease

Homogenates of a human brain from a case of Creutzfeldt-Jakob disease and a homogenate of mouse brains from mouse passage 1 of the disease in mice contained no detectable conventional viruses. Both human material and mouse-passaged material were inoculated into nude mice, and the mouse-passaged material was also inoculated into eight different tissue culture lines. The tissue cultures showed no cytopathic changes or hemadsorption and failed to produce an increased amount of reverse transcriptase. The nude mice inoculated with human brain suspensions developed a disease identical to that in immunocompetent mice, with a nearly identical incubation period of 9 to 13 months. The incubation period of the disease in mice was under host genetic control and was, additionally, directly related to the inoculum size. The agent was resistant to 10% Formalin, 5% deoxycholate, 1% Triton X-100, and 5% glutaraldehyde; however, glutaraldehyde treatment resulted in a significant loss of infectivity. Approximately 1 log of infectivity was lost by heating brain suspensions to 80 degrees C for 15 min, with no additional loss upon further incubation up to 45 min. Heating at 100 degrees C for 15 min led to a 3-log loss of infectivity.

Monoclonal antibody specific for myelin glycoprotein P0: derivation and characterization

A monoclonal antibody was produced against the major structural glycoprotein (P0) of human peripheral nervous system myelin. The hybridomas were generated by fusion of mouse myeloma line NS-1 with spleen cells of C3H mice immunized with purified human peripheral nervous system myelin. Hybridomas were screened by a two-step solid-phase radioimmunoassay, with P0 adsorbed on microtiter plates and with addition of 125I-labeled rabbit anti-mouse IgG as the second step. One derived clone, designated 41G10, bound P0 in the radioimmunoassay 4-fold over the background value obtained by using bovine serum albumin as the negative control antigen. Clone 41G10 was shown by immunofluorescence to bind to frozen sections of human intercostal nerve. Diffuse fluorescent staining occurred uniformly over the entire myelin sheath. The cylindrical axons were unstained. The same pattern of immunofluorescence was noted on rat, hamster, mouse, and rabbit sciatic nerve. Immunofluorescence was abolished when 41G10 was absorbed by P0. The monoclonal antibody 41G10 was absorbed by P0. The monoclonal antibody 41G10 is of the IgM class and activated complement in the presence of myelin vesicles or P0 liposomes but not in their absence.

Enzyme-linked immunosorbent assay (ELISA) for the detection of antibody to cysticerci of Taenia solium

An enzyme-linked immunosorbent assay (ELISA) for the detection of antibody to cysticerci of Taenia solium has been developed that employs a pork muscle antigen control for the cysticercus test antigen, somewhat improving the serological distinction between infected and uninfected subjects. Serum antibody to cysticercus was detected in 79% of classical neurocysticercosis patients from Mexico, and in 61% of a group of cysticercosis patients with an unusually rapid invasion of the central nervous system in an endemic focus of disease in Irian Jaya. Antibody was absent in a group of healthy American laboratory personnel, and in residents of a non-endemic region of Papua New Guinea. Additional test on sera from patients with other parasitic diseases showed that cross-reactivity may occur in some patients with schistosomiasis, echinococcosis, and possibly angiostrongyliasis; however, these parasites are not known to cause human infection in Irian Jaya.

Inability to transmit scrapie by transfection of mouse embryo cells in vitro

Infectivity of nucleic acid from highly infectious mouse scrapie brains was studied by transfecting the nucleic acid in vitro prior to inoculation into animals. Foetal mouse brain and whole mouse embryo cultures were chosen as the cells used for the transfection. As an internal control, infectious nucleic acid was recovered from bacteriophage phi X174 and whole virus particles were obtained when cultures were transfected with herpes simplex virus DNA. In contrast, none of the animals inoculated with nucleic acid preparations derived from scrapie-infected tissues developed scrapie disease either with or without transfection procedures. These findings (i) show transfection techniques fail to elicit evidence of a scrapie-specific infectious nucleic acid and (ii) confirm the observation that scrapie is not a viroid.

Longitudinal spinal cord sections as substratum for anti-neurofilament antibody detection

A rapid and technically simple method for demonstrating anti-neurofilament antibodies using longitudinal sections of rat spinal cord as substratum and indirect immunofluorescent technique is reported. The results compare well with those obtained by the technically more difficult and time-consuming methods using as substratum central neurons cultivated in vitro. A total of 195 serum specimens from different neurological disorders and healthy subjects were studied. Immunofluorescent autoantibodies to neurofilaments were found in specimens of serum from patients with Creutzfeldt-Jakob disease (CJD), kuru, amyotrophic lateral sclerosis, parkinsonism dementia (Guam), Alzheimer's disease, and multiple sclerosis but in higher frequency in CJD and kuru than in the other disease or in healthy control subjects.

Indirect immunofluorescence tests in Korean hemorrhagic fever and epidemic (endemic) nephropathia: treatment at low pH for removal of 'nonspecific' fluorescence in tissues from immunocompetent hosts

A 'nonspecific' fluorescence probably caused by immunocomplexes appears in the lung tissue of immunocompetent hosts infected with Korean hemorrhagic fever (KHF) or epidemic nephropathy (EN) viruses. Indirect immunofluorescence tests with such KHF- or EN-infected tissue as antigen are unsatisfactory for the detection of low-titer antibody or the reading of titer endpoints. Treatment of acetone-fixed lung sections at pH 3.0 followed by washing with 0.01 M phosphate-buffered saline and distilled water apparently dissolves the immunocomplexes, resulting in an effective removal of the 'nonspecific' fluorescence while the viral antigens are not significantly impaired. Lung sections of KHF-infected Apodemus agrarius coreae and EN-infected Clethrionomys glareolus, acetone-fixed and treated at pH 3.0, were used for the antigenic differentiation of the EN and KHF viruses.