Expression of the simian varicella virus glycoprotein E.

Simian varicella virus (SVV) is closely related to human varicella-zoster virus (VZV) and induces a varicella-like disease in nonhuman primates. The SVV genome encodes a glycoprotein E (gE) which is homologous to the gE of VZV and other alphaherpesviruses. The SVV gE was expressed in Escherichia coli and rabbits were immunized with the recombinant gE fusion proteins to generate polyclonal gE antiserum. Immunofluorescence and immunoprecipitation analyses demonstrated that the SVV gE is expressed on the surface and within SVV-infected cells. The gE is also expressed on SVV virions as indicated by serum neutralization assay. The mature SVV gE is glycosylated and is similar in size ( approximately 100 kd) to the mature VZV gE. Immunohistochemical analysis detected gE within skin vesicles and lung tissue of SVV-infected monkeys. Analysis of the humoral immune response to gE in an SVV-infected monkey determined that anti-gE antibody is induced as early as day 9 postinfection and persists at high titer for longer than 4 months. The simian varicella model offers an opportunity to investigate the role of gE in viral pathogenesis and immunity and to evaluate its potential as a varicella vaccine.

Construction, safety, and immunogenicity in nonhuman primates of a chimeric yellow fever-dengue virus tetravalent vaccine.

We previously reported construction of a chimeric yellow fever-dengue type 2 virus (YF/DEN2) and determined its safety and protective efficacy in rhesus monkeys (F. Guirakhoo et al., J. Virol. 74:5477-5485, 2000). In this paper, we describe construction of three additional YF/DEN chimeras using premembrane (prM) and envelope (E) genes of wild-type (WT) clinical isolates: DEN1 (strain PUO359, isolated in 1980 in Thailand), DEN3 (strain PaH881/88, isolated in 1988 in Thailand), and DEN4 (strain 1228, isolated in 1978 in Indonesia). These chimeric viruses (YF/DEN1, YF/DEN3, and YF/DEN4) replicated to ~7.5 log(10) PFU/ml in Vero cells, were not neurovirulent in 3- to 4-week-old ICR mice inoculated by the intracerebral route, and were immunogenic in monkeys. All rhesus monkeys inoculated subcutaneously with one dose of these chimeric viruses (as monovalent or tetravalent formulation) developed viremia with magnitudes similar to that of the YF 17D vaccine strain (YF-VAX) but significantly lower than those of their parent WT viruses. Eight of nine monkeys inoculated with monovalent YF/DEN1 -3, or -4 vaccine and six of six monkeys inoculated with tetravalent YF/DEN1-4 vaccine seroconverted after a single dose. When monkeys were boosted with a tetravalent YF/DEN1-4 dose 6 months later, four of nine monkeys in the monovalent YF/DEN groups developed low levels of viremia, whereas no viremia was detected in any animals previously inoculated with either YF/DEN1-4 vaccine or WT DEN virus. An anamnestic response was observed in all monkeys after the second dose. No statistically significant difference in levels of neutralizing antibodies was observed between YF virus-immune and nonimmune monkeys which received the tetravalent YF/DEN1-4 vaccine or between tetravalent YF/DEN1-4-immune and nonimmune monkeys which received the YF-VAX. However, preimmune monkeys developed either no detectable viremia or a level of viremia lower than that in nonimmune controls. This is the first recombinant tetravalent dengue vaccine successfully evaluated in nonhuman primates.

Simian varicella virus infects ganglia before rash in experimentally infected monkeys.

Monkeys experimentally infected with simian varicella virus (SVV) develop rash 10-14 days later. However, the route and the time of ganglionic infection are unknown. Using PCR, we analyzed DNA extracted from tissues of 13 monkeys 5 to 60 days after either intratracheal or intravenous inoculation with SVV. SVV DNA was detected in ganglia from four of five monkeys sacrificed 6 to 7 days after intratracheal inoculation. Further, analysis of ganglia from monkeys sacrificed at 10 days revealed that intravenous inoculation produced a higher proportion of SVV DNA-positive ganglia (63%) than that after intratracheal inoculation (13%), pointing to the role of hematogenous spread in ganglionic infection. Like other organs, monkey ganglia become infected with SVV before the appearance of rash.

Comparative dermal pharmacology and toxicology of 4,4'-dihydroxybenzophenone-2,4-dinitrophenylhydrazone (A-007) in rodents and primates.

4,4'-Dihydroxybenzophenone-2,4-ditrophenylhydrazone (A-007) has demonstrated anticancer activities, when administered topically to patients with metastatic cancer to the skin. Acute, subacute and subchronic dermal studies with A-007 in adult rabbits, rats, guinea pigs and monkeys failed to demonstrate local or systemic toxicity when applied topically as a 0.25% gel. A-007 did not penetrate the dermal lymphatics and did not produce detectable levels of A-007 in the plasma when applied as a 0.25% gel topically to skin. In the above studies, topically administered A-007 stimulated local sub-epithelial and dermal lymphocyte modulation, with increased CD8+ cytotoxic lymphocytes (CTL) noted, in guinea pig skin. Generally topical A-007 is well tolerated and may have useful immune modulation properties.

Sequence analysis of the leftward end of simian varicella virus (EcoRI-I fragment) reveals the presence of an 8-bp repeat flanking the unique long segment and an 881-bp open-reading frame that is absent in the varicella zoster virus genome.

Simian varicella virus (SVV) causes varicella (chickenpox) in nonhuman primates, becomes latent in cranial and dorsal root ganglia, and reactivates to produce zoster (shingles). Because the clinical and molecular features of SVV closely resemble those of varicella zoster virus (VZV) infection of humans, SVV infection of primates has served as an experimental model of VZV pathogenesis and latency. The SVV genome has been completely mapped, but attempts to clone the 3600-bp EcoRI fragment located at the leftward end of the virus genome have hitherto been unsuccessful. Herein, we report the cloning and the complete nucleotide sequence of this region. Comparison of the SVV and VZV sequences in this region revealed an 8-bp inverted repeat sequence flanking the unique long segment of the SVV genome; an 879-bp open-reading frame (ORF) A in SVV that is absent in VZV but has 42% amino acid identity to SVV ORF 4 and 49% to VZV ORF 4; a 342-bp ORF B in SVV with 35% amino acid identity to a 387-bp ORF located to the left of ORF 1 on the VZV genome; and a 303-bp ORF in SVV with 27% amino acid identity to VZV ORF 1. No homologue of VZV ORF 2 was detected. Transcripts specific for ORFs A and B were present in SVV-infected cells in culture and in acutely infected monkey ganglia. Overall, there are more than 2000 bp of DNA in the SVV genome that are absent in the VZV genome.

Outbreak of Orthoreovirus-induced meningoencephalomyelitis in baboons.

BACKGROUND AND PURPOSE: Spontaneous viral encephalitis is rare in the baboon; yet, during a 13-month period (1993-1994), eight juvenile baboons (Papio cynocephalus spp.) developed acute, progressive nonsuppurative meningoencephalomyelitis caused by an unknown agent. Clinical signs of disease included disorientation and truncal ataxia that rapidly progressed to hemiparesis or paraparesis. Clinicopathologic findings were not remarkable and appreciable gross lesions were not seen at necropsy. Microscopic examination revealed CNS lesions that were characterized by lymphoplasmacytic perivascular cuffing, microglial nodules, demyelination, axonal degeneration, vacuolization, and hemorrhage. Subsequently, a novel syncytium-inducing mammalian orthoreovirus was isolated from the brain tissue of five baboons with clinical signs of infection. METHODS: To confirm the etiologic role of the orthoreovirus, two juvenile baboons were inoculated with the virus, then were monitored for 6 weeks. RESULTS: Lesions similar to those seen in spontaneous cases were found in the CNS, and orthoreovirus was isolated from the brain of both animals. CONCLUSION: Analysis of the outbreak indicated juvenile baboons were most susceptible to disease and the virus had a possible incubation time of 46 to 66 days, but did not indicate a source of the virus or mode of transmission.

Recombinant chimeric yellow fever-dengue type 2 virus is immunogenic and protective in nonhuman primates.

A chimeric yellow fever (YF)-dengue type 2 (dengue-2) virus (ChimeriVax-D2) was constructed using a recombinant cDNA infectious clone of a YF vaccine strain (YF 17D) as a backbone into which we inserted the premembrane (prM) and envelope (E) genes of dengue-2 virus (strain PUO-218 from a case of dengue fever in Bangkok, Thailand). The chimeric virus was recovered from the supernatant of Vero cells transfected with RNA transcripts and amplified once in these cells to yield a titer of 6.3 log(10) PFU/ml. The ChimeriVax-D2 was not neurovirulent for 4-week-old outbred mice inoculated intracerebrally. This virus was evaluated in rhesus monkeys for its safety (induction of viremia) and protective efficacy (induction of anti-dengue-2 neutralizing antibodies and protection against challenge). In one experiment, groups of non-YF-immune monkeys received graded doses of ChimeriVax-D2; a control group received only the vaccine diluents. All monkeys (except the control group) developed a brief viremia and showed no signs of illness. Sixty-two days postimmunization, animals were challenged with 5.0 log(10) focus forming units (FFU) of a wild-type dengue-2 virus. No viremia (<1.7 log(10) FFU/ml) was detected in any vaccinated group, whereas all animals in the placebo control group developed viremia. All vaccinated monkeys developed neutralizing antibodies in a dose-dependent response. In another experiment, viremia and production of neutralizing antibodies were determined in YF-immune monkeys that received either ChimeriVax-D2 or a wild-type dengue-2 virus. Low viremia was detected in ChimeriVax-D2-inoculated monkeys, whereas all dengue-2-immunized animals became viremic. All of these animals were protected against challenge with a wild-type dengue-2 virus, whereas all YF-immune monkeys and nonimmune controls became viremic upon challenge. Genetic stability of ChimeriVax-D2 was assessed by continuous in vitro passage in VeroPM cells. The titer of ChimeriVax-D2, the attenuated phenotype for 4-week-old mice, and the sequence of the inserted prME genes were unchanged after 18 passages in Vero cells. The high replication efficiency, attenuation phenotype in mice and monkeys, immunogenicity and protective efficacy, and genomic stability of ChimeriVax-D2 justify it as a novel vaccine candidate to be evaluated in humans.

Chimeric yellow fever virus 17D-Japanese encephalitis virus vaccine: dose-response effectiveness and extended safety testing in rhesus monkeys.

ChimeriVax-JE is a live, attenuated recombinant virus prepared by replacing the genes encoding two structural proteins (prM and E) of yellow fever 17D virus with the corresponding genes of an attenuated strain of Japanese encephalitis virus (JE), SA14-14-2 (T. J. Chambers et al., J. Virol. 73:3095-3101, 1999). Since the prM and E proteins contain antigens conferring protective humoral and cellular immunity, the immune response to vaccination is directed principally at JE. The prM-E genome sequence of the ChimeriVax-JE in diploid fetal rhesus lung cells (FRhL, a substrate acceptable for human vaccines) was identical to that of JE SA14-14-2 vaccine and differed from sequences of virulent wild-type strains (SA14 and Nakayama) at six amino acid residues in the envelope gene (E107, E138, E176, E279, E315, and E439). ChimeriVax-JE was fully attenuated for weaned mice inoculated by the intracerebral (i.c.) route, whereas commercial yellow fever 17D vaccine (YF-Vax) caused lethal encephalitis with a 50% lethal dose of 1.67 log(10) PFU. Groups of four rhesus monkeys were inoculated by the subcutaneous route with 2.0, 3.0, 4.0, and 5. 0 log(10) PFU of ChimeriVax-JE. All 16 monkeys developed low viremias (mean peak viremia, 1.7 to 2.1 log(10) PFU/ml; mean duration, 1.8 to 2.3 days). Neutralizing antibodies appeared between days 6 and 10; by day 30, neutralizing antibody responses were similar across dose groups. Neutralizing antibody titers to the homologous (vaccine) strain were higher than to the heterologous wild-type JE strains. All immunized monkeys and sham-immunized controls were challenged i.c. on day 54 with 5.2 log(10) PFU of wild-type JE. None of the immunized monkeys developed viremia or illness and had mild residual brain lesions, whereas controls developed viremia, clinical encephalitis, and severe histopathologic lesions. Immunized monkeys developed significant (>/=4-fold) increases in serum and cerebrospinal fluid neutralizing antibodies after i.c. challenge. In a standardized test for neurovirulence, ChimeriVax-JE and YF-Vax were compared in groups of 10 monkeys inoculated i.c. and analyzed histopathologically on day 30. Lesion scores in brains and spinal cord were significantly higher for monkeys inoculated with YF-Vax. ChimeriVax-JE meets preclinical safety and efficacy requirements for a human vaccine; it appears safer than yellow fever 17D vaccine but has a similar profile of immunogenicity and protective efficacy.

Immunization of rhesus monkeys with a mucosal prime, parenteral boost strategy protects against infection with Helicobacter pylori.

Rhesus monkeys were immunized with recombinant Helicobacter pylori urease vaccine given solely by the parenteral route or preceded by a priming dose given by the oral route. Two groups of monkeys received parenteral urease with either a synthetic glycolipid adjuvant (Bay) or aluminum hydroxide (alum) as adjuvants. A third group of monkeys received a priming dose of oral urease given with the mucosal adjuvant LT (Escherichia coli heat labile enterotoxin), followed by parenterally administered booster doses of urease adsorbed to alum. Monkeys receiving placebo served as controls. The monkeys received a total of 4 doses of vaccine with the first 3 doses given every 3 weeks and the last booster dose administered 14 weeks later. The monkeys were challenged orally with H. pylori one week after the last vaccine dose and euthanized 10 weeks after challenge, at which time, their stomachs were collected for determination of bacterial colonization and histopathology. Monkeys primed with the oral vaccine and boosted with the parenteral vaccine showed a statistically significant reduction in bacterial colonization when compared to sham-immunized control animals (P = 0.05; Wilcoxon rank sums test). Monkeys receiving parenteral only regimes of urease plus Bay or alum showed no difference in bacterial colonization compared with sham-immunized controls (P = 1.00 and P = 0.33, respectively). The mucosal prime-parenteral boost regime did not cause gastropathy. There was no difference in any of the 3 treatment groups with respect to gastric epithelial changes compared to control animals. There was also no difference in the type and extent of gastric inflammatory cell infiltrates between animals vaccinated by the mucosal prime-parenteral boost strategy and sham immunized controls. However, monkeys receiving the two parenteral-only regimens had slightly elevated gastritis scores.

Genetically engineered Mengo virus vaccination of multiple captive wildlife species.

Encephalomyocarditis virus (EMCV), has caused the deaths of many species of animals in zoological parks and research institutions. The Audubon Park Zoo, (New Orleans, Louisiana, USA) attempted vaccination of several species with a killed EMCV vaccine with mixed results. This paper reports an attempt at vaccination against EMCV using a genetically engineered, live attenuated Mengo virus (vMC0) at the Audubon Park Zoo and Miami Metro Zoo, (Miami, Florida, USA) from December 1996 to June 1997. Several species of animals were vaccinated with vMC0, which is serologically indistinguishable from the field strain of EMCV. Serum samples were taken at the time of vaccination and again 21 days later, then submitted for serum neutralization titers against EMCV. The vaccinate species included red capped mangebey (Cercocebus torquatus), colobus (Colobus guereza), angolan colobus (Colobus angolensis), ruffed lemur (Lemur variegatus ruber and Lemur variegatus variegatus), back lemur (Lemur macaco), ring-tailed lemur (Lemur catta), siamang (Hylobates syndactylus), diana guenon (Cercopithicus diana), spider monkey (Ateles geoffroyi), common marmoset (Callithrix jacchus), talapoin monkey (Cercopithecus talapoin), Brazilian tapir (Tapirus terrestris), Baird's tapir (Tapirus bairdii), Malayan tapir (Tapirus indicus), dromedary camel (Camelus dromedarius), bactrian camel (Camelus bactrianus), gerenuk (Litocranius walleri), guanaco (Lama glama guanicoe), black duiker (Cephalophus niger), Vietnamese potbellied pig (Sus scrofa), babirusa (Babyrousa babyrussa), collard peccary (Tayass tajacu), and African crested porcupine (Hystrix africaeaustralis). The vaccine response was variable, with high virus neutralizing antibody titer responses in some primate species and mixed to poor responses for other species. No ill effects were seen with vaccination.

Recombinant, chimaeric live, attenuated vaccine (ChimeriVax) incorporating the envelope genes of Japanese encephalitis (SA14-14-2) virus and the capsid and nonstructural genes of yellow fever (17D) virus is safe, immunogenic and protective in non-human primates.

Yellow fever 17D virus, a safe and effective live, attenuated vaccine, was used as a vector for genes encoding the protective antigenic determinants of a heterologous member of the genus Flavivirus, Japanese encephalitis (JE) virus, the leading cause of acute viral central nervous system infection and death throughout Asia. The viral envelope (prM and E) genes of a full-length cDNA clone of YF 17D virus were replaced with the corresponding genes of JE SA14-14-2, a strain licensed as a live, attenuated vaccine in China. Full-length RNA transcripts of the YF/JE chimaera were used to transfect Vero cells. The progeny virus (named 'ChimeriVax-JE'), was used to define safety after intracerebral (i.c.) inoculation of rhesus monkeys. Monkeys (N = 3) inoculated with a high dose (6.6 log10 pfu) developed a brief viremia, showed no signs of illness, developed high titers of anti-JE neutralizing antibody, and had minimal brain and spinal cord lesion scores according to criteria specified in the WHO monkey neurovirulence test. A control group of 3 monkeys that received a lower dose (4.2 log10 pfu) of commercial YF 17D vaccine had slightly higher lesion scores. To develop a lethal monkey model of JE for vaccine protection tests, we inoculated groups of monkeys i.c. or intranasally (i.n.) with a JE virus strain found to be highly neurovirulent and neuroinvasive for mice. Monkeys inoculated i.c., but not i.n., developed severe encephalitis after an incubation period of 8-13 days. The ChimeriVax-JE virus was passed in a cell line acceptable for human use (diploid fetal rhesus lung) and 4.3 or 5.3 log10 pfu were inoculated into groups of 3 monkeys by the subcutaneous route. All 6 animals developed brief viremias (peak titer < 2.0 log10 pfu/ml) and subsequently had anti-JE but no yellow fever neutralizing antibodies. On day 64, the monkeys were challenged i.c. with 5.5 log10 pfu of virulent JE virus. The immunized animals had no detectable viremia post-challenge, whereas 4 unimmunized controls became viremic. Only 1 of 6 (17%) vaccinated monkeys but 4 of 4 (100%) unvaccinated controls developed encephalitis. Histopathological examination 30 days after challenge confirmed that the protected, immunized animals had no or minimal evidence of encephalitis. These data demonstrated the ability of the ChimeriVax-JE to induce a rapid humoral immune response and to protect against a very severe, direct intracerebral virus challenge. Target areas of neuronal damage and inflammation in monkeys infected IC with wild-type JE, the chimaeric virus and YF 17D were similar, indicating that the histopathological scoring system used for the WHO yellow fever monkey neurovirulence test will be applicable to control testing of chimaeric seed viruses and vaccines.

Immunization with recombinant Helicobacter pylori urease decreases colonization levels following experimental infection of rhesus monkeys.

Rhesus monkeys, naturally colonized with H. pylori as indicated by culture and histology were immunized with either 40 mg recombinant H. pylori urease administered orally together with 25 microg Escherichia coli heat-labile enterotoxin (LT) or immunized with LT alone. An initial 6 doses were administered over an 8 week period. All five vaccinated monkeys had a greater than two-fold rise in urease-specific serum IgG and IgA level and urease-specific salivary IgA was induced in 3 of 5 vaccinated animals after 6 or 7 doses of vaccine. Vaccination had no measurable therapeutic effect on H. pylori colonization. H. pylori was eradicated from these monkeys with a course of antimicrobials plus omeprazole, a 7th vaccine dose was given (10 months after the 6th dose) and they were rechallenged with H. pylori. Necropsy was performed 23 weeks after rechallenge and H. pylori colonization was determined by histological examination of 12 individual gastric sites. A significant reduction in colonization (p < or = 0.0001; Friedman's analysis of variance) was found in the vaccinated animals. Histopathologic examination of necropsy tissues also revealed a trend towards reduced gastritis and epithelial alterations in the vaccinated group compared to animals receiving LT alone. This study provides the first evidence for effective vaccination of nonhuman primates against H. pylori, and preliminary evidence that a reduction in bacterial density attributable to immunization may lessen gastric inflammation.

Infectious simian varicella virus expressing the green fluorescent protein.

Clinical, pathologic, immunologic and virologic features of simian varicella virus (SVV) infection in primates closely resemble varicella-zoster virus (VZV) infection in humans. Such similarities provide a rationale to analyze SVV infection in primates as a model of varicella pathogenesis and latency. Thus, we constructed an SVV-expressing green fluorescent protein (SVV-GFP) by inserting the GFP gene into the unique short segment of the virus genome by homologous recombination. Analysis of recombinant viral DNA and the expressed proteins of plaque-purified SVV-GFP confirmed the location of the GFP insert and that the recombinant SVV expressed the 27 kDa GFP. Infection of monkey kidney cells in tissue culture with SVV-GFP revealed bright green fluorescence associated with the characteristic focal cytopathic effect produced by SVV infection. Microscopic examination of lung from a 3-month-old African green monkey 10 days after infection with SVV-GFP revealed bright green fluorescence in areas of acute necrotizing pneumonitis. SVV-GFP allows ready identification of cells infected with SVV both in vitro and in vivo, and will be useful for further analysis of varicella pathogenesis and latency in experimentally infected animals--studies not possible in humans.

Rapid diagnosis of simian varicella using the polymerase chain reaction.

Simian varicella virus (SVV) causes sporadic epizootics of a varicella-like disease in nonhuman primates. Rapid diagnosis of simian varicella is critical in controlling epizootics. A polymerase chain reaction (PCR)-based diagnostic assay for detection of SVV DNA in cell culture and clinical samples from SVV-infected monkeys was developed. The assay is rapid, specific, and highly sensitive. The SVV DNA is readily detected in skin rash specimens and in peripheral blood lymphocytes of infected monkeys during the early stages of clinical varicella. In addition to providing an important diagnostic tool, the SVV PCR assay is also useful for investigating the epidemiology and pathogenesis of simian varicella.

Experimental simian varicella virus infection of St. Kitts vervet monkeys.

Experimental simian varicella virus (SVV) infection of St. Kitts vervet monkeys was evaluated as an animal model to investigate human varicella-zoster virus (VZV) infections. During the incubation period, viremia disseminated infectious virus throughout the body via infected peripheral blood lymphocytes (PBLs). A vesicular skin rash in the inguinal area, and on the abdomen, extremities, and face appeared on day 7-10 postinfection. Necrosis and hemorrhage in lung and liver tissues from acutely infected monkeys were evident upon histologic analysis. Recovery from simian varicella was accompanied by a rise in the serum neutralizing antibody response to the virus. SVV latency was established in trigeminal ganglia of monkeys which resolved the acute infection. This study indicates that experimental SVV infection of St. Kitts vervets is a useful animal model to investigate SVV and VZV pathogenesis and to evaluate potential antiviral agents and vaccines.

Intranasal Sendai virus vaccine protects African green monkeys from infection with human parainfluenza virus-type one.

Human parainfluenza virus-type I (hPIV-1) infections are a common cause of "group" and hospitalizations among young children. Here we address the possibility of using the xenotropic Sendai virus [a mouse parainfluenza virus (PIV)] as a vaccine for hPIV-1. Sendai virus was administered to six African green monkeys (Cercopithecus aethiops) by the intranasal (i.n.) route. A long lasting virus-specific antibody response was elicited, both in the serum and nasal cavity. Sendai virus caused no apparent clinical symptoms in the primates, but live virus was detected in the nasal cavity for several days after inoculation. No virus was detected after a second dose of Sendai virus was administered on day 126 after the initial priming. Animals were challenged with hPIV-1 i.n. on day 154. All six vaccinated animals were fully protected from infection while six of six control animals were infected with hPIV-1. The antibody responses induced by Sendai virus immunizations proved to be greater than those induced by hPIV-1. These results demonstrate that unmanipulated Sendai virus is an effective vaccine against hPIV-1 in a primate model and may constitute a practical vaccine for human use.

Further observations on coronavirus infection of primate CNS.

Previously, we demonstrated that intracerebral (IC) inoculation of a murine coronavirus, MHV-JHM, into two species of primates can result in acute encephalomyelitis (Murray et al., 1992a). Infectious virus isolated from acutely infected animals, designated JHM-OMp1, was inoculated IC into a second group of monkeys. In this report we describe observations on the acutely infected animals and those surviving the acute infection were sacrificed at later times post-infection. Results from dual in situ hybridization/immunohistochemistry screening of tissues show that astrocytes are target cells in white matter lesions during acute infection. In animals sacrificed 150 days post-infection, areas of demyelinated gliotic lesions, prominent in the spinal cord, were seen throughout the neuraxis. No virus products were detected in these late-infection lesions.

Comparative preclinical toxicology and pharmacology of 4,4'-dihydroxybenzophenone-2,4-dinitrophenylhydrazone (A-007) in vitro and in rodents and primates.

4,4'-Dihydroxybenzophenone-2,4-dinitrophenylhydrazone (A-007) is being evaluated for its anticancer activities. Acute, subacute and chronic oral, dermal, opthalmic and dermal LD50 and acceptance studies in adult mice, rats, rabbits and monkeys demonstrated some vomiting at 5 g/kg doses in monkeys but otherwise no unacceptable toxicities. In vitro, T.I. for A-007 were calculated using murine bone marrow GM-CFC and human cancer cell lines. A relative oral bioavailability factor of 2% was calculated for rats and monkeys for plasma A-007. Non-compartmental pharmacokinetic analysis suggests enterohepatic circulation. Plasma A-007 could not be detected after applying a 0.25% gel topically. Generally, A-007 is well tolerated.

Intranasal monoclonal IgA antibody to respiratory syncytial virus protects rhesus monkeys against upper and lower respiratory tract infection.

Respiratory syncytial virus (RSV), the major cause of lower respiratory tract disease in infants, is thought to infect the upper airways before spreading to the lower respiratory tract. A rhesus monkey model of RSV infection after upper airway inoculation was used to test the protective effect of intranasal treatment with HNK20, a mouse monoclonal IgA antibody against RSV F glycoprotein. HNK20 was administered once daily for 2 days before RSV challenge and 4 days after challenge. Treatment with 0.5 mg/kg HNK20 reduced viral shedding in the nose, throat, and lungs by 3-4 log10/mL (P < or = .002). All monkeys developed RSV neutralizing antibody in serum, even in the absence of detectable viral replication. Neutralizing concentrations of monoclonal antibody remained in nasal secretions for > 1 day after treatment. These results suggest that nose-drop application of monoclonal antibody could provide convenient and effective protection against RSV infection in human infants at risk of severe lower respiratory tract disease.

Temporal association of interferon-alpha and p27 core antigen levels in sera of simian immunodeficiency virus infected monkeys.

We report the temporal association of interferon (IFN) and p27 core antigen production during experimental simian immunodeficiency virus Delta B670 (SIV) infection in rhesus monkeys. Peak serum IFN-alpha levels (10(2.8-5.0)U/ml) occurred 10 days post infection (p.i.) and peak p27 levels (3.1-34.4 ng/ml) occurred 10-14 days p.i. Acid-stable IFN-alpha (10(1.6-2.5)U/ml) was detected 3-5 days before p27 in sera from three monkeys and was detected with p27 (0.06-3.06 ng/ml) in four monkeys during the primary infection. Serum IFN-alpha and p27 levels became undetectable 24-40 days p.i. Two monkeys remained asymptomatic for SIV after the primary p27 antigenaemia, three monkeys had recrudescent (3-4 months p.i.) acid stable interferonaemias (10(1-2.5)U/ml) with p27 antigenaemias (0.06-2.7 ng/ml) that persisted until death, and two monkeys had acute SIV infections (died < or = 7 months p.i.) with persistent acid-stable interferonaemia (10(1.6-2.5)U/ml) and p27 antigenaemia (6-9 ng/ml). Our results indicate that the detection of acid-stable IFN-alpha in serum is closely associated with detection of p27 (P = 0.0001) and suggest that detection of acid-stable IFN-alpha and p27 core antigen is indicative of active SIV infection.