Preclinical and clinical studies on immunogenicity and safety of the HIV-1 p17-based synthetic peptide AIDS vaccine--HGP-30-KLH

Immunization with a synthetic HIV-1 p17 peptide analog (HGP-30; aa 85-115 of HIV p17), coupled to a carrier protein (KLH, keyhole limpet hemocyanin) given with alum as the adjuvant induces antibodies which cross-react with both HGP-30 and HIV p17 and clones of cytotoxic and helper T-cells which recognize HGP-30 and HIV p17. Proliferation of lymphocytes in response to HGP-30 has been observed in mice, in HIV-infected individuals and in healthy HIV-seronegative volunteers vaccinated with the p17-based synthetic peptide construct. Cytotoxic T-cell responses against EBV transformed, recombinant p17 pulsed targets were observed using antigen-expanded PBLs from HGP-30-KLH immunized individuals. These results are consistent with predictions that the HGP-30 domain of HIV p17 contains both T- and B-cell epitopes that are recognized by animals and humans. In preclinical toxicology studies in animals and in initial clinical trials in humans the synthetic peptide construct (HGP-30-KLH/alum) has been shown to be safe. This paper summarizes the preclinical immunogenicity and safety data for HGP-30-KLH and presents the initial results from the first Phase 1 clinical trial.

Combination ultrafiltration and 6 M urea treatment of human growth hormone effectively minimizes risk from potential Creutzfeldt-Jakob disease virus contamination

Although genetically engineered human growth hormone (hGH) is now commercially available, native pituitary-derived hGH is still used by physicians in many countries for the treatment of hormone deficiency states. We describe a method using ultrafiltration and 6 M urea that reduced infectivity in human pituitary tissue that had been deliberately contaminated with scrapie virus (an animal analogue of human Creutzfeldt-Jakob disease virus) from an initial level of 10(9.7) infectious units to just 5 infectious units. Based on estimates of the frequency of contamination and infectivity levels in batches of human pituitaries, the use of this protocol to prepare GH from cadaveric human glands yields a calculated probability of exposure to a contaminated vial of not greater than 1 in 3.2 million recipients; therefore, native hormone prepared by this method may be considered to be essentially risk-free. The same methodology may be useful in the preparation of other hormones, such as prolactin, for which no synthetic substitutes are currently available, as well as biological products derived from sheep or cattle, that may be infected with scrapie or bovine spongiform encephalopathy.

In situ hybridization detection of HTLV-I RNA in peripheral blood mononuclear cells of TSP/HAM patients and their spouses

This is the first report of the direct detection of HTLV-I RNA in uncultured peripheral blood mononuclear cells (PBMNC's) of patients with tropical spastic paraparesis and HTLV-I-associated myelopathy (TSP/HAM) and their spouses, using the technique of in situ hybridization. Twenty-one Colombian patients were tested, all of whom had antibodies to HTLV-I; the presence of HTLV-I proviral DNA in their PBMNC's was confirmed by the polymerase chain reaction technique. Of the 21 patients 15 had a clinical diagnosis of tropical spastic paraparesis (TSP/HAM), 5 were asymptomatic relatives, and 1 patient had leukemia. In situ hybridization was positive in samples from 5 patients; 2 of these were TSP/HAM patients and the other 3 were healthy wives of TSP/HAM patients. This study demonstrates for the first time that viral RNA is expressed in uncultured PBMNC's of some patients with TSP/HAM in whom proviral DNA is also present; furthermore, the detection of HTLV-I RNA in the blood of female partners of TSP/HAM patients clearly illustrates the high likelihood of HTLV-I transmission through sexual contact.

[HTLV-I retrovirus in Chile: study on 140 neurological patients]

We screened 140 patients with different neurological diseases for the presence of anti HTLV-1 virus antibodies. ELISA test confirmed with Western Blot analysis was performed in CSF and blood. Positive findings were obtained in 23 out of 52 patients with progressive spastic paraparesis (44%). All patients with multiple sclerosis, polymyositis, amyotrophic lateral sclerosis or chronic polyneuropathy were negative. Patients with progressive spastic paraparesis and positive HTLV-1 antibodies were most commonly women (78%) and middle aged (mean 46 years old), with a history of surgical interventions (70%) or blood transfusion (35%). A slowly progressive spastic paraparesis with asymmetric onset and minimal sensory complaints was observed in some cases. Mononuclear pleocytosis in the CSF was observed in 35% with an increased IgG index in 88%. A delayed latency and low amplitude of somatosensory evoked potentials was observed in 89% of patients.

Steroid-responsive myeloneuropathy in a man dually infected with HIV-1 and HTLV-I

Two human retroviruses, HIV-1 and HTLV-I, have been associated with myelopathies in addition to other neurologic disorders. We report an American dually infected with HIV-1 and HTLV-I who developed steroid-responsive myeloneuropathy. This 28-year-old bisexual man developed interstitial pneumonitis and a transient midthoracic sensory level followed by the evolution of a slowly progressive spastic paraparesis and sensorimotor neuropathy. Serologic studies demonstrated coinfection with both HIV-1 and HTLV-I. Peripheral blood absolute CD4 count was persistently within the normal range. Cranial MRI was normal and spinal MRI showed T3-T10 atrophy. Serial CSF analyses demonstrated marked intrathecal synthesis of anti-HTLV-I IgG, lymphocytic pleocytosis, elevated protein and immunoglobulin G, and oligoclonal bands. HIV-1 was isolated from CSF but not from peripheral nerve. Lymphoproliferative studies confirmed spontaneous proliferation in both blood and CSF. Soluble interleukin 2 receptor and soluble CD8 were greatly elevated in blood and CSF when compared with patients with HIV-related vacuolar myelopathy and seronegative patients with other causes of myelopathy. Nerve biopsy showed epi- and endoneurial CD8+ lymphocytic infiltration without vasculitis; muscle biopsy showed features of acute and chronic denervation. A 6-week course of prednisone produced sustained improvement in leg strength and walking times. We speculate that the myeloneuropathy was caused by HTLV-I in the setting of coinfection with HIV-1.

Detection of measles virus genomic sequences in SSPE brain tissue by the polymerase chain reaction

The polymerase chain reaction (PCR) was modified to detect RNA genomic sequences by generating cDNA copies of these sequences as a preliminary step. Oligonucleotide primer pairs complementary to sequences in each of the five major structural protein genes of the measles virus (nucleocapsid protein, phosphoprotein, matrix protein, fusion protein, and hemagglutinin protein) were synthesized. PCR products were tentatively identified by visualization of bands of the appropriate size by ethidium bromide staining after gel electrophoresis, and identity was confirmed by subsequent restriction enzyme cleavage of the products at predetermined sites to yield fragments of predicted size. This method successfully amplified 400-500 base regions from each of these five genes in RNA extracts of wild measles virus cultured in Vero cells and in RNA extracted from most of the SSPE brain tissues tested, but not in RNA from any control brain tissues. Measles virus genome was detected in SSPE brain tissues stored frozen for as long as 27 years and formalin-fixed paraffin-embedded subacute sclerosing panencephalitis (SSPE) brain tissues as old as 9 years. This method provides a simple, rapid and highly sensitive means of detecting and identifying sequences of RNA genomes by PCR. The success of this method in detecting measles virus in SSPE brain tissue suggests that PCR is appropriate to investigate the possible presence of RNA viruses in other neurological disorders of unknown etiology.

Scrapie-associated precursor proteins: antigenic relationship between species and immunocytochemical localization in normal, scrapie, and Creutzfeldt-Jakob disease brains

We describe the antigenic properties and detection of a normal isoform of scrapie-associated precursor protein (PrP33-35C) in normal, and both normal and scrapie isoforms in scrapie- or Creutzfeldt-Jakob disease (CJD)-infected mouse, hamster, and human brains, using a variety of specific antibodies. Polyclonal antibodies raised against mouse and hamster PrP27-30 and against a synthetic peptide of the N-terminal sequence of this protein were used as immunologic probes. PrP27-30 purified as a primary immunogen corresponded to the lower molecular mass peptide, with Mr between 9.3 and 13.5 kd as estimated by size-exclusion high-pressure liquid chromatography. ELISA and immunoblot techniques demonstrated that antibodies recognized homologous antigens as well as precursor proteins from brains (PrP33-35C) and the scrapie isoform of scrapie-associated proteins (PrP33-35Sc/CJD and PrP27-30) from scrapie- and CJD-infected brains. The normal, scrapie, and CJD isoforms of scrapie-associated proteins share common epitopes with varying degrees of interspecies homology. Specific antigen detected in neurons indicated that these proteins are synthesized primarily in these cells. In infected brains, extracellular amyloid deposits formed by the scrapie isoform of PrP protein also strongly reacted with anti-PrP antibodies.

Immunohistochemical localization of prion protein in spongiform encephalopathies and normal brain tissue

We used polyclonal antibodies raised against hamster and mouse PrP27-30 as immunologic probes to study the localization of intracellular and extracellular deposits of prion protein in normal and scrapie-infected mouse and hamster brains and in Creutzfeldt-Jakob disease (CJD)-infected mouse brains. In addition, we examined normal human brain and brain tissues from patients with CJD, kuru, Alzheimer's disease, and idiopathic chronic encephalitis. There was positive staining in the cytoplasm of neurons of normal and scrapie- and CJD-infected mice, and in the neurons of normal and scrapie-infected hamsters. The staining pattern suggests the localization of PrP in an intracellular membrane compartment, most likely the rough endoplasmic reticulum or Golgi apparatus. Antibodies raised against a 15-amino-acid synthetic peptide of the N-terminal of hamster PrP27-30 displayed a similar pattern of staining in mouse brain sections. We observed no intracellular staining in human brain sections obtained at autopsy. Antibodies prepared against mouse and hamster PrP27-30 reacted with amyloid plaques in scrapie-infected mouse and kuru- and CJD-infected human brain sections but not with amyloid plaques in the brain of a patient with Alzheimer's disease.

Subcellular distribution and physicochemical properties of scrapie-associated precursor protein and relationship with scrapie agent

We studied the biologic properties of hamster-adapted scrapie (strain 263K) and its relationship to the precursor protein of scrapie (PrP33-35Sc). The highest titer of infectious material and the greatest concentration of PrP33-35Sc were in the fractions containing microsomal and synaptosomal membranes. We found traces of infectivity in the absence of PrP33-35Sc associated with matrix protein. Partitioning of membranes with neutral chloroform-methanol resulted in concentration of PrP33-35Sc and infectivity within the interphase layer. Recombination of membrane glycoproteins (interphase) with lipids extracted from homologous brains decreased infectivity greater than or equal to 4 logs. Temperature-dependent phase separation of infected synaptosomal and microsomal membranes with Triton X-114 yielded a phospholipid-rich phase containing a high concentration of PrP33-35Sc and greatest infectivity titers. This material spontaneously formed liposomes, indicating that PrP33-35Sc and PrP33-35C precursor proteins are highly hydrophobic intrinsic membrane components integrated with phospholipids. Homologous membrane phospholipids appear to prevent aggregation of the scrapie isoform of PrP and maintain high levels of infectivity.

Scrapie infectivity and prion protein are distributed in the same pH range in agarose isoelectric focusing

We separated lysed synaptosomal-microsomal membrane fraction from scrapie-infected hamster brain in preparative agarose isoelectric focusing. We also studied the distribution of PrP27-30 and scrapie infectivity in 13 regions of the gel in the range of pH 3.5 to 9.3. Most of the infectivity remained in the trough, where it had been placed at the beginning of the electrophoresis, along with PrP27-30. Scrapie infectious particles that encountered the gel demonstrated charge heterogeneity and were distributed in the range of pH 5.4 to 9.3. Analysis of charge heterogeneity of PrP27-30 after sodium dodecyl sulfate solubilization showed an isoelectric pattern in the same pH range as that for scrapie infectious particles. The similarity in charge heterogeneity between infectivity and PrP27-30, together with copurification, support the idea that PrP27-30 is an essential component of the scrapie infectious agent.

Spread of Creutzfeldt-Jakob disease virus along visual pathways after intraocular inoculation

We studied the targeting of spongiform lesions within the visual pathways after intraocular injection with the Fujisaki strain of Creutzfeldt-Jakob disease (CJD) virus. The first lesions were observed 18 weeks postinoculation in the most superficial layer of the superior colliculus and in the lateral geniculate body contralateral to the side of the inoculation. Asymmetrical lesions in the superior colliculus were found also in mice sacrificed at 19, 22, and 27 weeks postinoculation. These results demonstrate that CJD virus spreads within the CNS via central axons of the visual pathways following intraocular inoculation.

Coexistence of Creutzfeldt-Jakob disease and Alzheimer's disease in the same patient

We report the case of a 73-year-old patient in whom a diagnosis of Creutzfeldt-Jakob disease, suggested by the clinical course, was verified by the neuropathologic finding of widespread spongiform change and astrogliosis, the presence of proteinase-resistant protein in brain extracts, and the experimental transmission of spongiform encephalopathy to primates inoculated with brain tissue. However, neuropathologic examination also revealed a profusion of senile and neuritic plaques and neurofibrillary tangles that reacted with antibody to the amyloid beta-protein characteristic of Alzheimer's disease, but not with antibody to the scrapie amyloid protein characteristic of Creutzfeldt-Jakob disease.

Reevaluation of the ultrastructural pathology of experimental Creutzfeldt-Jakob disease. Serial studies of the Fujisaki strain of Creutzfeldt-Jakob disease virus in mice

We describe the serial ultrastructural pathology of experimental Creutzfeldt-Jakob disease (CJD) in mice. Spongiform vacuoles, widespread myelin and axonal pathology, accompanied by abundant macrophagic reaction and neuroaxonal dystrophy, were consistently found in mice infected with CJD virus. By contrast, intranuclear vacuolation and swelling of astrocytic and neuronal processes were nonspecific changes that also occurred in control animals. We conclude that CJD-related neuropathological phenomena do not accumulate gradually through the incubation period but develop relatively abruptly and in complete form.

Appearance of tubulovesicular structures in experimental Creutzfeldt-Jakob disease and scrapie precedes the onset of clinical disease

We have consistently observed tubulovesicular structures in brain tissues during the terminal stages of naturally occurring and experimentally induced spongiform encephalopathies, irrespective of the host species and virus strain. In NIH Swiss mice inoculated intracerebrally or intraocularly with the Fujisaki strain of Creutzfeldt-Jakob disease (CJD) virus, tubulovesicular structures, measuring 20-50 nm in diameter, were particularly prominent in dilated, pre- and postsynaptic neuronal processes, occasionally being mixed with synaptic vesicles. These structures appeared 13 weeks following intracerebral inoculation, 5 weeks before the onset of clinical signs, when spongiform changes were also detected. The number and density of tubulovesicular structures increased steadily during the course of clinical disease, and were particularly abundant in mice 47 to 51 weeks after intraocular inoculation. In hamsters infected with the 263 K strain of scrapie virus, these structures were initially detected 3 weeks following intracerebral inoculation and increased dramatically at 10 weeks postinoculation. The appearance of tubulovesicular structures before the onset of overt disease in mice inoculated with CJD virus by either the intracerebral or intraocular route, and before the appearance of other neuropathological changes in hamsters infected with scrapie virus, indicate that they represent either a part or aggregate of the infectious virus or a pathological product of the infection.

Change in a public sector health setting: some factors contributing to success

The differential impact of two action research projects involving the implementation of change in a public sector psychiatric health setting was examined. Particular factors which influenced the projects were the political and policy environment and the internal organisational culture. Implications for the management of change and for the policy implementation process are discussed.

Scrapie as a model for neuroaxonal dystrophy: ultrastructural studies

Neuritic degeneration is a prominent ultrastructural feature of scrapie in hamsters. To investigate the morphogenesis of neuritic degeneration, we examined brain tissues from hamsters infected with the 263K strain of scrapie virus and from age-matched controls at varying intervals following intracerebral inoculation. Dystrophic neurites--defined as dendrites, axonal preterminals, and myelinated axons containing mitochondria and pleomorphic, electron-dense inclusion bodies--were found as early as 2 weeks postinoculation. Their numbers increased with the incubation period, and their highest density was observed at the terminal stage of disease. Occasionally, small clusters of these structures formed neuritic plaques. Such dystrophic neurites were only rarely seen in brains of uninfected hamsters. Experimental scrapie thus provides an animal model for human neuroaxonal dystrophies. In addition, since this model allows predictable formation of brain amyloid, it may serve as a model for the study of neuronal aging and Alzheimer's disease.

Serial ultrastructural studies of scrapie in hamsters

We report sequential studies of the ultrastructural neuropathology of the subcortical grey matter of hamsters infected with the 263K strain of scrapie virus. Vacuolation in this model develops relatively late in the incubation period, while tubulovesicular structures appear early. Furthermore, neuroaxonal dystrophy, accumulations of branching tubules, and neuronal change consisting of intracytoplasmic "whorls" of proliferating membranes constitute prominent features of scrapie-related neurodegeneration.

White matter ultrastructural pathology of experimental Creutzfeldt-Jakob disease in mice

Creutzfeldt-Jakob disease (CJD), previously regarded as a neurodegenerative disorder strictly of the gray matter, occasionally occurs as a panencephalopathic form which is characterized by severe white matter damage. An ultrastructural study of the white matter pathology in mice experimentally infected with the Fujisaki strain of CJD virus revealed: (1) vacuoles within myelin sheaths, formed by splitting either at the major dense or intraperiod lines, or within axons; (2) macrophages filled with numerous myelin figures, lipid droplets and paracrystalline inclusions; (3) astrocytes actively digesting myelin debris; (4) unusual wrapping of several axons by a common myelin sheath; (5) vesicular degeneration of myelin sheaths; (6) close contact between numerous coated pits and outer myelin lamellae; and (7) proliferation of inner mesaxons. Our data indicate that the damage to myelinated axons in the panencephalopathic type of CJD is accomplished primarily by active degradation of myelin by macrophages and astrocytes and by formation of intra-axonal and intra-myelin vacuoles. The myelin vacuolation is most consistent with that produced by leukolysins released from activated macrophages and astrocytes.

Isolation and characterization of HTLV-I from symptomatic family members with tropical spastic paraparesis (HTLV-I encephalomyeloneuropathy)

Human T lymphotropic virus type I (HTLV-I) was isolated from peripheral blood- and cerebrospinal fluid-derived mononuclear cells of a 13-y-old boy and from the peripheral blood lymphocytes of both his parents. All three had IgG antibodies to HTLV-I and varying degrees of the clinical features of tropical spastic paraparesis (TSP). The son also had IgM antibodies specific for HTLV-I in his serum. Isolations were successfully made from peripheral blood lymphocytes and cerebrospinal fluid lymphocytes stimulated with interleukin-2 or cocultivated with umbilical cord blood mononuclear cells. Established cell lines contained HTLV-I antigen by immunfluorescence and cell-associated virus by electron microscopy; cells became transformed in vitro as determined by their continuous growth in the absence of exogenous interleukin-2. This boy is the youngest TSP patient known to be reported, and the isolation of HTLV-I from all three family members suggests the causative role of this virus in TSP.

Hemorrhagic fever with renal syndrome in Yugoslavia: antigenic characterization of hantaviruses isolated from Apodemus flavicollis and Clethrionomys glareolus

Hantavirus antigens were detected in lung tissues of 8/113 Apodemus flavicollis and 2/17 Clethrionomys glareolus captured in 1984 in Fojnica, a region of Yugoslavia endemic for hemorrhagic fever with renal syndrome; hantavirus antigens were not detected in lung tissues from 126 other mammals collected in Fojnica. Three hantaviruses, 2 from A. flavicollis and 1 from C. glareolus, were isolated directly in Vero E6 cells and were partially characterized. The isolates from A. flavicollis, designated Fojnica virus, were antigenically similar but not identical to Hantaan virus strain 76-118, whereas the isolate from C. glareolus was antigenically indistinguishable from Puumala virus, strain Hällnäs B1. These data are consistent with previous studies that indicate the existence of at least 2 hantavirus serotypes in Yugoslavia.