Multi-Omic blood analysis reveals differences in innate inflammatory sensitivity between species

Vertebrates differ greatly in responses to pro-inflammatory agonists such as bacterial lipopolysaccharide (LPS), complicating use of animal models to study human sepsis or inflammatory disorders. We compared transcriptomes of resting and LPS-exposed blood from six LPS-sensitive species (rabbit, pig, sheep, cow, chimpanzee, human) and four LPS-resilient species (mice, rats, baboon, rhesus), as well as plasma proteomes and lipidomes. Unexpectedly, at baseline, sensitive species already had enhanced expression of LPS-responsive genes relative to resilient species. After LPS stimulation, maximally different genes in resilient species included genes that detoxify LPS, diminish bacterial growth, discriminate sepsis from SIRS, and play roles in autophagy and apoptosis. The findings reveal the molecular landscape of species differences in inflammation, and may inform better selection of species for pre-clinical models.

Single-component multilayered self-assembling protein nanoparticles presenting glycan-trimmed uncleaved prefusion optimized envelope trimmers as HIV-1 vaccine candidates

Uncleaved prefusion-optimized (UFO) design can stabilize diverse HIV-1 envelope glycoproteins (Envs). Single-component, self-assembling protein nanoparticles (1c-SApNP) can display 8 or 20 native-like Env trimers as vaccine candidates. We characterize the biophysical, structural, and antigenic properties of 1c-SApNPs that present the BG505 UFO trimer with wildtype and modified glycans. For 1c-SApNPs, glycan trimming improves recognition of the CD4 binding site without affecting broadly neutralizing antibodies (bNAbs) to major glycan epitopes. In mice, rabbits, and nonhuman primates, glycan trimming increases the frequency of vaccine responders (FVR) and steers antibody responses away from immunodominant glycan holes and glycan patches. The mechanism of vaccine-induced immunity is examined in mice. Compared with the UFO trimer, the multilayered E2p and I3-01v9 1c-SApNPs show 420 times longer retention in lymph node follicles, 20-32 times greater presentation on follicular dendritic cell dendrites, and up-to-4 times stronger germinal center reactions. These findings can inform future HIV-1 vaccine development.

Comparison of oral, nebulized and combination antibiotic treatment of Bordetella bronchiseptica in baboons (Papio spp.)

Incidence of Bordetella pertussis, the causative agent of whooping cough, is rising in some global human populations despite high vaccination rates, and significant research is underway to address the issue. Baboons are an established model for pertussis research, but like many mammals, they can be naturally infected with Bordetella bronchiseptica. Because B. bronchiseptica interferes with B. pertussis research, it must be excluded from baboons under consideration for enrollment in pertussis studies. In addition to research-related concerns, B. bronchiseptica can sometimes cause clinical disease in baboons and other nonhuman primates. This study examined the use of antibiotics to clear B. bronchiseptica in naturally infected baboons. Thirty-five juvenile baboons were divided into five treatment groups: oral sulfamethoxazole/trimethoprim (TMS), nebulized gentamicin (gentamicin), combination (TMS + gentamicin) in positive animals, combination (TMS + gentamicin) as a prophylactic in exposed animals and no treatment (control). Combination of oral TMS and nebulized gentamicin given to positive animals was most effective, producing long-term clearance in 11 out of 12 treated animals. To avoid unnecessary use of antibiotics, our primary management strategy is screening and separating to allow natural clearance and limiting exposure to non-infected animals, but this study investigates an antibiotic regimen that could be used in special circumstances.

Functional convergence of a germline-encoded neutralizing antibody response in rhesus macaques immunized with HCV envelope glycoproteins

Human IGHV1-69-encoded broadly neutralizing antibodies (bnAbs) that target the hepatitis C virus (HCV) envelope glycoprotein (Env) E2 are important for protection against HCV infection. An IGHV1-69 ortholog gene, VH1.36, is preferentially used for bnAbs isolated from HCV Env-immunized rhesus macaques (RMs). Here, we studied the genetic, structural, and functional properties of VH1.36-encoded bnAbs generated by vaccination, in comparison to IGHV1-69-encoded bnAbs from HCV patients. Global B cell repertoire analysis confirmed the expansion of VH1.36-derived B cells in immunized animals. Most E2-specific, VH1.36-encoded antibodies cross-neutralized HCV. Crystal structures of two RM bnAbs with E2 revealed that the RM bnAbs engaged conserved E2 epitopes using similar molecular features as human bnAbs but with a different binding mode. Longitudinal analyses of the RM antibody repertoire responses during immunization indicated rapid lineage development of VH1.36-encoded bnAbs with limited somatic hypermutation. Our findings suggest functional convergence of a germline-encoded bnAb response to HCV Env with implications for vaccination in humans.

Woolly Monkey-HBV Infection in Squirrel Monkeys as a Surrogate Nonhuman Primate Model of HBV Infection

Development of curative therapies for chronic hepatitis B virus (HBV) infection will likely require new animal models. Here, we evaluate HBV infection in squirrel monkeys based on the high-sequence homology of the HBV receptor, Na+/taurocholate co-transporting peptide (NTCP), between humans and squirrel monkeys. HBV PreS1 peptide was examined for binding human and squirrel monkey NTCP. Immunodeficient Fah -/- , NOD, Rag1 -/- , Il2Rg null (FNRG) mice engrafted with human or squirrel monkey hepatocytes were challenged with HBV or Woolly Monkey HBV (WMHBV). In addition, adult squirrel monkeys were inoculated with HBV, WMHBV, adeno-associated virus containing an infectious genome of HBV (AAV-HBV), and AAV-WMHBV. Finally, neonate squirrel monkeys were assessed for the potential of chronic infection with WMHBV. PreS1 peptide efficiently bound to human and squirrel monkey NTCP but not to mouse or capuchin NTCP. FNRG mice engrafted with squirrel monkey hepatocytes were susceptible to infection by WMHBV but not human HBV. Similarly, adult squirrel monkeys could be infected with WMHBV but not human HBV, whereas chimeric mice engrafted with human hepatocytes were susceptible to HBV but not WMHBV. Infection of squirrel monkeys with AAV-WMHBV yielded maximum viremia of 108 genomes/mL with detectable virus for up to 8 months. Notably, covalently closed circular DNA was detected in the liver of these animals. Infection of neonates with WMHBV led to detectable viremia for up to 6 months. Conclusions: Adult and neonate squirrel monkeys exhibited prolonged WMHBV viremia lasting 6-8 months. This is greater than twice the duration of viremia achieved in other nonhuman primates and suggests that squirrel monkeys may be a suitable model for testing HBV therapeutics.

Antibody Responses to Immunization With HCV Envelope Glycoproteins as a Baseline for B-Cell-Based Vaccine Development

BACKGROUND & AIMS

We investigated antibody responses to hepatitis C virus (HCV) antigens E1 and E2 and the relevance of animal models for vaccine development. We compared antibody responses to vaccination with recombinant E1E2 complex in healthy volunteers, non-human primates (NHPs), and mice.

METHODS

We analyzed 519 serum samples from participants in a phase 1 vaccine trial (ClinicalTrials.gov identifier NCT00500747) and compared them with serum or plasma samples from C57BL/6J mice (n = 28) and rhesus macaques (n = 4) immunized with the same HCV E1E2 antigen. Blood samples were collected at different time points and analyzed for antibody binding, neutralizing activity, and epitope specificity. Monoclonal antibodies from the immunized NHPs were isolated from single plasmablasts and memory B cells, and their immunogenetic properties were characterized.

RESULTS

Antibody responses of the volunteers, NHPs, and mice to the non-neutralizing epitopes on the E1 N-terminus and E2 hypervariable region 1 did not differ significantly. Antibodies from volunteers and NHPs that neutralized heterologous strains of HCV primarily interacted with epitopes in the antigen region 3. However, the neutralizing antibodies were not produced in sufficient levels for broad neutralization of diverse HCV isolates. Broadly neutralizing antibodies similar to the human V_H1-69 class antibody specific for antigen region 3 were produced in the immunized NHPs.

CONCLUSIONS

In an analysis of vaccinated volunteers, NHPs, and mice, we found that recombinant E1E2 vaccine antigen induces high-antibody titers that are insufficient to neutralize diverse HCV isolates. Antibodies from volunteers and NHPs bind to the same neutralizing epitopes for virus neutralization. NHPs can therefore be used as a preclinical model to develop HCV vaccines. These findings also provide useful baseline values for development of vaccines designed to induce production of neutralizing antibodies.

Subclinical Infection of Macaques and Baboons with A Baboon Simarterivirus

Simarteriviruses (Arteriviridae: Simarterivirinae) are commonly found at high titers in the blood of African monkeys but do not cause overt disease in these hosts. In contrast, simarteriviruses cause severe disease in Asian macaques upon accidental or experimental transmission. Here, we sought to better understand the host-dependent drivers of simarterivirus pathogenesis by infecting olive baboons (n = 4) and rhesus monkeys (n = 4) with the simarterivirus Southwest baboon virus 1 (SWBV-1). Surprisingly, none of the animals in our study showed signs of disease following SWBV-1 inoculation. Three animals (two rhesus monkeys and one olive baboon) became infected and sustained high levels of SWBV-1 viremia for the duration of the study. The course of SWBV-1 infection was highly predictable: plasma viremia peaked between 1 × 10⁷ and 1 × 10⁸ vRNA copies/mL at 3–10 days post-inoculation, which was followed by a relative nadir and then establishment of a stable set-point between 1 × 10⁶ and 1 × 10⁷ vRNA copies/mL for the remainder of the study (56 days). We characterized cellular and antibody responses to SWBV-1 infection in these animals, demonstrating that macaques and baboons mount similar responses to SWBV-1 infection, yet these responses are ineffective at clearing SWBV-1 infection. SWBV-1 sequencing revealed the accumulation of non-synonymous mutations in a region of the genome that corresponds to an immunodominant epitope in the simarterivirus major envelope glycoprotein GP5, which likely contribute to viral persistence by enabling escape from host antibodies.

RNAi-based treatment of chronically infected patients and chimpanzees reveals that integrated hepatitis B virus DNA is a source of HBsAg

Chronic hepatitis B virus (HBV) infection is a major health concern worldwide, frequently leading to liver cirrhosis, liver failure, and hepatocellular carcinoma. Evidence suggests that high viral antigen load may play a role in chronicity. Production of viral proteins is thought to depend on transcription of viral covalently closed circular DNA (cccDNA). In a human clinical trial with an RNA interference (RNAi)-based therapeutic targeting HBV transcripts, ARC-520, HBV S antigen (HBsAg) was strongly reduced in treatment-naïve patients positive for HBV e antigen (HBeAg) but was reduced significantly less in patients who were HBeAg-negative or had received long-term therapy with nucleos(t)ide viral replication inhibitors (NUCs). HBeAg positivity is associated with greater disease risk that may be moderately reduced upon HBeAg loss. The molecular basis for this unexpected differential response was investigated in chimpanzees chronically infected with HBV. Several lines of evidence demonstrated that HBsAg was expressed not only from the episomal cccDNA minichromosome but also from transcripts arising from HBV DNA integrated into the host genome, which was the dominant source in HBeAg-negative chimpanzees. Many of the integrants detected in chimpanzees lacked target sites for the small interfering RNAs in ARC-520, explaining the reduced response in HBeAg-negative chimpanzees and, by extension, in HBeAg-negative patients. Our results uncover a heretofore underrecognized source of HBsAg that may represent a strategy adopted by HBV to maintain chronicity in the presence of host immunosurveillance. These results could alter trial design and endpoint expectations of new therapies for chronic HBV.

Ascariasis as cause of intestinal occlusion and concurrent appendicitis

Intestinal occlusion by ascariasis is a commonly seen socio-economic status low, is associated with poor sanitary hygiene. It is rare to see a case with both intestinal occlusion and appendicitis at the same time, as described in this report.

Characterization of γδT cells in naïve and HIV-infected chimpanzees and their responses to T-cell activators in vitro

BACKGROUND

γδT cells are effector cells that eliminate cancer and virus-infected cells. Chimpanzees are an endangered species that can naturally and experimentally be infected with SIV and HIV, respectively, but no information about the functionality of γδT cells during chronic lentiviral infection is currently available.

METHODS

Healthy and HIV-infected chimpanzee γδT cells were characterized by flow cytometry. γδT subsets were studied after stimulation with T-cell activators, and the release of cytokines was analyzed by Luminex assay.

RESULTS

γδT-cell subsets, Vδ1 and Vδ2Vγ9, showed different patterns in the expression of CD4, CD195, CD159a, and CD159c. Stimulation of γδT cells resulted in increased levels of CD4 and HLA-DR, which is more pronounced in Vδ1 T cells. Distinct cytokine patterns were found between healthy and HIV-infected chimpanzees.

CONCLUSIONS

Analyses of major chimpanzee γδT subsets show similarities to human γδT cells and suggest different functionality and roles in their immune response against HIV infection.

GS-9620, an oral agonist of Toll-like receptor-7, induces prolonged suppression of hepatitis B virus in chronically infected chimpanzees

BACKGROUND & AIMS

Direct-acting antiviral agents suppress hepatitis B virus (HBV) load, but they require life-long use. Stimulation of the innate immune system could increase its ability to control the virus and have long-lasting effects after a finite regimen. We investigated the effects of immune activation with GS-9620--a potent and selective orally active small molecule agonist of Toll-like receptor 7--in chimpanzees with chronic HBV infection.

METHODS

GS-9620 was administered to chimpanzees every other day (3 times each week) for 4 weeks at 1 mg/kg and, after a 1-week rest, for 4 weeks at 2 mg/kg. We measured viral load in plasma and liver samples, the pharmacokinetics of GS-9620, and the following pharmacodynamics parameters: interferon-stimulated gene expression, cytokine and chemokine levels, lymphocyte and natural killer cell activation, and viral antigen expression. Clinical pathology parameters were monitored to determine the safety and tolerability of GS-9620.

RESULTS

Short-term oral administration of GS-9620 provided long-term suppression of serum and liver HBV DNA. The mean maximum reduction of viral DNA was 2.2 logs, which occurred within 1 week of the end of GS-9620 administration; reductions of >1 log persisted for months. Serum levels of HBV surface antigen and HBV e antigen, and numbers of HBV antigen-positive hepatocytes, were reduced as hepatocyte apoptosis increased. GS-9620 administration induced production of interferon-α and other cytokines and chemokines, and activated interferon-stimulated genes, natural killer cells, and lymphocyte subsets.

CONCLUSIONS

The small molecule GS-9620 activates Toll-like receptor 7 signaling in immune cells of chimpanzees to induce clearance of HBV-infected cells. This reagent might be developed for treatment of patients with chronic HBV infection.

Antiviral activity and host gene induction by tamarin and marmoset interferon-alpha and interferon-gamma in the GBV-B primary hepatocyte culture model

GBV-B induces hepatitis in tamarins and marmosets and is a surrogate model for HCV infections. Here, we cloned and characterized the antiviral activity of tamarin and marmoset interferon (IFN)alpha and IFN gamma. Potent antiviral activity was observed for tamarin and marmoset IFN alpha in primary hepatocyte cultures infected with GBV-B. The antiviral activity was greater in cultures exposed to IFN alpha prior to GBV-B infection, suggesting that either GBV-B was capable of inhibition of the antiviral activity of exogenous IFN alpha or that the preexisting endogenous IFN response to the virus reduced efficacy to exogenous IFN alpha. IFN gamma also exhibited antiviral activity in GBV-B infected hepatocytes. The transcriptional response to IFN alpha in marmoset hepatocytes was characterized using human genome microarrays. Since the GBV-B hepatocyte culture model possesses a functional innate immune response, it will provide opportunities to explore the nature of the antiviral response to a virus closely related to HCV.

Lack of response to exogenous interferon-alpha in the liver of chimpanzees chronically infected with hepatitis C virus

The mechanism of the interferon-alpha (IFNalpha)-induced antiviral response is not completely understood. We recently examined the transcriptional response to IFNalpha in uninfected chimpanzees. The transcriptional response to IFNalpha in the liver and peripheral blood mononuclear cells (PBMCs) was rapidly induced but was also rapidly down-regulated, with most interferon-alpha-stimulated genes (ISGs) returning to the baseline within 24 hours. We have extended these observations to include chimpanzees chronically infected with hepatitis C virus (HCV). Remarkably, using total genome microarray analysis, we observed almost no induction of ISG transcripts in the livers of chronically infected animals following IFNalpha dosing, whereas the response in PBMCs was similar to that in uninfected animals. In agreement with this finding, no decrease in the viral load occurred with up to 12 weeks of pegylated IFNalpha therapy. The block in the response to exogenous IFNalpha appeared to be HCV-specific because the response in a hepatitis B virus-infected animal was similar to that of uninfected animals. The lack of a response to exogenous IFNalpha may be due to an already maximally induced ISG response because chronically HCV-infected chimpanzees already have a highly up-regulated hepatic ISG response. Alternatively, negative regulation may block the response to exogenous IFNalpha, yet it does not prevent the continued response to endogenous ISG stimuli. The IFNalpha response in chronically HCV-infected chimpanzees may be mechanistically similar to the null response in the human population.

CONCLUSION

In chimpanzees infected with HCV, the highly elevated hepatic ISG expression may prevent the further induction of ISGs and antiviral efficacy following an IFNalpha treatment.

Menopausal symptoms and associated risk factors among postmenopausal women screened for the metabolic syndrome

BACKGROUND

Although the frequency of menopausal symptoms may vary according to the studied population, in general severe intensity has been related to lower quality of life.

OBJECTIVE

To assess the frequency of menopausal symptoms and involved risk factors in an Ecuadorian postmenopausal population.

METHODS

Postmenopausal women that participated in a metabolic syndrome screening program were interviewed with the Menopause-specific quality of life questionnaire (MENQOL) in order to determine the most frequently presenting menopausal symptoms and correlate these symptoms with socio-demographic data and the main results of the screening program.

RESULTS

Three hundred and twenty-five postmenopausal women (n = 325) were surveyed with the MENQOL. Mean age of participants was 55.9 +/- 8.1 years (median: 54 years). The most frequently presenting symptoms were: hot flushes (53.3%), sweating (49.2%), poor memory (80.6%), feeling depressed (67.4%), aching in muscles and joints (84%), drying of their skin (85.5%), avoiding intimacy (76.2%) and change in their sexual desire (76.5%). Multivariate analysis determined that abdominal obesity was a significant risk factor for presenting hot flushes, depression and muscle and joint pain. High triglyceride levels were associated to higher rates of sweating and depression. While women with basal hyperglycemia were associated to dry skin and changes in sexual desire in a higher proportion, those who were older and with more years of menopause onset were related less frequently to vasomotor symptoms. Older age was also significantly associated in a higher rate to dry skin.

CONCLUSION

In this postmenopausal Ecuadorian population, the frequency of menopausal symptoms, as assessed with the MENQOL, was found to be relatively similar to other Latin and non-Latin American populations and associated to age, hormonal status and related metabolic conditions.

Genomic response to interferon-alpha in chimpanzees: implications of rapid downregulation for hepatitis C kinetics

The mechanism of the interferon-alpha (IFN-alpha)-induced antiviral response during hepatitis C virus (HCV) therapy is n o t completely understood. In this study,we examined the transcriptional response to IFN-alpha in uninfected chimpanzees after single doses of chimpanzee, human, or human-pegylated IFN-alpha. Liver and peripheral blood mononuclear cell (PBMC) samples were used for total genome microarray analysis. Most induced genes achieved maximal response within 4 hours, began to decline by 8 hours, and were at baseline levels by 24 hours postinoculation, a time when high levels of circulating pegylated IFN-alpha were still present. The rapid downregulation of the IFN-alpha response may be involved in the transition between the observed phase I and phase II viral kinetics during IFN-alpha therapy in HCV-infected patients. The response to all three forms of IFN-alpha was similar; thus, the reasons for previous failures in antiviral treatment of chimpanzees with human IFN-alpha were not due to species specificity of IFN-alpha. The response to IFN-alpha was partially tissue-specific. A total of 1778 genes were altered in expression by twofold or more by IFN-alpha, with 538 and 950 being unique to the liver or PBMC, respectively. Analysis of the IFN-alpha and IFN-gamma responses in primary chimpanzee and human hepatocytes were compared as well. IFN-alpha and IFN-gamma induced partially overlapping sets of genes in hepatocytes. In conclusion, the response to IFN-alpha is largely tissue-specific, and the response is rapidly downregulated in vivo, which may have a significant influence on the kinetics of antiviral response.

Cross-genotype immunity to hepatitis C virus

Recent studies in humans and chimpanzees suggest that immunity can be induced to diminish the incidence of chronic hepatitis C virus (HCV) infection. However, the immunity that promotes viral recovery is poorly understood, and whether the breadth of this adaptive immunity is sufficient to overcome the substantial intergenotype antigenic diversity represents a final obstacle to demonstrating the feasibility of vaccine development. Here we demonstrate that recovery from a genotype 1 HCV infection protects chimpanzees against infection with representatives of other genotypes that exhibit up to 30% divergence at the amino acid level, including challenges with genotype 4, a mixture of genotypes 2 and 3, and a complex inoculum containing genotypes 1, 2, 3, and 4. In each instance, the level and duration of viremia were markedly reduced in comparison to the primary infection in the same animal. The data indicate that epitopes conserved between genotypes must play an essential role in immunity. The inocula used in the rechallenge studies induced typical primary infection profiles in naïve chimpanzees. Rechallenge infections were associated with rapid increases in the intrahepatic transcripts of interferon-stimulated genes, even in animals exhibiting apparent sterilizing immunity. Protective immunity was often associated with an early increase in gamma interferon transcripts in the liver and increases in intrahepatic transcripts of Mig, a T-cell chemokine that is a gamma interferon response gene. These studies are the first to show that cross-genotype immunity can be induced to HCV, demonstrating the feasibility of developing a vaccine protective against all HCV strains.

An infectious clone of woolly monkey hepatitis B virus

Members of the Hepadnaviridae family have been isolated from birds, rodents, and primates. A new hepadnavirus isolated from the woolly monkey, a New World primate, is phylogenetically distinct from other primate isolates. An animal model has been established for woolly monkey hepatitis B virus (WMHBV) by using spider monkeys, since woolly monkeys are endangered. In this study, a greater-than-genome length construct was prepared without amplification by using covalently closed circular DNA extracted from the liver of an infected woolly monkey. Transfection of the human liver cell line Huh7 with WMHBV DNA resulted in the production of viral transcripts, DNA replicative intermediates, and secreted virions at levels similar to those obtained with an infectious human HBV clone, demonstrating that the host range restriction of WMHBV is not at the level of genome replication. WMHBV particles from the medium of transfected cultures initiated an infection in a spider monkey similar to that obtained with virions derived from woolly monkey serum. In an attempt to adapt the virus for higher levels of replication in spider monkeys, immunosuppressed and newborn animals were inoculated. Neither procedure produced persistent infections, and the level of viral replication remained several logs lower than that observed in persistently infected woolly monkeys. These data demonstrate the production of an infectious clone for WMHBV and extend the characterization of the spider monkey animal model.

Comparison of tamarins and marmosets as hosts for GBV-B infections and the effect of immunosuppression on duration of viremia

GBV-B virus is a close relative to hepatitis C virus (HCV) that causes hepatitis in tamarins, and thus, is an attractive surrogate model for HCV. In this study, we demonstrate that the host range of GBV-B extends to the common marmoset with an infection profile similar to that observed for tamarins. Marmoset hepatocytes were susceptible to in vitro infection with GBV-B. Virus was efficiently secreted into the medium, and approximately 25% of hepatocytes were positive for NS3 staining. In an attempt to induce persistent infections, tamarins were immunosuppressed with FK506 and inoculated with GBV-B. Although no chronic infections were induced, the duration of viremia was increased in most animals. In one animal, the duration of viremia was extended to 46 weeks, but viral clearance occurred 18 weeks after stopping FK506 therapy. The greater availability of marmosets in comparison to tamarins will greatly facilitate future research efforts with this model.

Antiviral effect and virus-host interactions in response to alpha interferon, gamma interferon, poly(i)-poly(c), tumor necrosis factor alpha, and ribavirin in hepatitis C virus subgenomic replicons

The recently developed hepatitis C virus (HCV) subgenomic replicon system was utilized to evaluate the efficacy of several known antiviral agents. Cell lines that persistently maintained a genotype 1b replicon were selected. The replicon resident in each cell line had acquired adaptive mutations in the NS5A region that increased colony-forming efficiency, and some replicons had acquired NS3 mutations that alone did not enhance colony-forming efficiency but were synergistic with NS5A mutations. A replicon constructed from the infectious clone of the HCV-1 strain (genotype 1a) was not capable of inducing colony formation even after the introduction of adaptive mutations identified in the genotype 1b replicon. Alpha interferon (IFN-alpha), IFN-gamma, and ribavirin exhibited antiviral activity, while double-stranded RNA (dsRNA) and tumor necrosis factor alpha did not. Analysis of transcript levels for a series of genes stimulated by IFN (ISGs) or dsRNA following treatment with IFN-alpha, IFN-gamma, and dsRNA revealed that both IFNs increased ISG transcript levels, but that some aspect of the dsRNA response pathway was defective in Huh7 cells and replicon cell lines in comparison to primary chimpanzee and tamarin hepatocytes. The colony-forming efficiency of the replicon was reduced or eliminated following replication in the presence of ribavirin, implicating the induction of error-prone replication. The potential role of error-prone replication in the synergy observed between IFN-alpha and ribavirin in attaining sustained viral clearance is discussed. These studies reveal characteristics of Huh7 cells that may contribute to their unique capacity to support HCV RNA synthesis and demonstrate the utility of the replicon system for mechanistic studies on antiviral agents.

Ribavirin induces error-prone replication of GB virus B in primary tamarin hepatocytes

GB virus B (GBV-B) is the closest relative of hepatitis C virus (HCV) and is an attractive surrogate model for HCV antiviral studies. GBV-B induces an acute, resolving hepatitis in tamarins. Utilizing primary cultures of tamarin hepatocytes, we have previously developed a tissue culture system that exhibits high levels of GBV-B replication. In this report, we have extended the utility of this system for testing antiviral compounds. Treatment with human interferon provided only a marginal antiviral effect, while poly(I-C) yielded >3 and 4 log units of reduction of cell-associated and secreted viral RNA, respectively. Interestingly, treatment of GBV-B-infected hepatocytes with ribavirin resulted in an approximately 4-log decrease in viral RNA levels. Guanosine blocked the antiviral effect of ribavirin, suggesting that inhibition of IMP dehydrogenase (IMPDH) and reduction of intracellular GTP levels were essential for the antiviral effect. However, mycophenolic acid, another IMPDH inhibitor, had no antiviral effect. Virions harvested from ribavirin-treated cultures exhibited a dramatically reduced specific infectivity. These data suggest that incorporation of ribavirin triphosphate induces error-prone replication with concomitant reduction in infectivity and that reduction of GTP pools may be required for incorporation of ribavirin triphosphate. In contrast to the in vitro studies, no significant reduction in viremia was observed in vivo following treatment of tamarins with ribavirin during acute infection with GBV-B. These findings are consistent with the observation that ribavirin monotherapy for HCV infection decreases liver disease without a significant reduction in viremia. Our data suggest that nucleoside analogues that induce error-prone replication could be an attractive approach for the treatment of HCV infection if administered at sufficient levels to result in efficient incorporation by the viral polymerase.

GB virus B as a model for hepatitis C virus

GB viruses A and B (GBV-A and GBV-B) are members of the Flaviviridae family and are isolated from tamarins injected with serum from a human hepatitis patient. Along with a related human virus, GB virus C, or alternatively, hepatitis G virus (GBV-C/HGV), the three viruses represent the GB agents. Of the three viruses, GBV-B has been proposed as a potential surrogate model for the study of hepatitis C virus (HCV) infections of humans. GBV-B is phylogenetically most closely related to HCV and causes an acute, self-resolving hepatitis in tamarins as indicated by an increase in alanine aminotransferase and changes in liver histology. Similarities between GBV-B and HCV are found at the nucleotide sequence level with the two viruses sharing 28% amino acid homology over the lengths of their open reading frames. Short regions have even higher levels of homology that are functionally significant as shown by the ability of the GBV-B NS3 protease to cleave recombinant HCV polyprotein substrates. The shared protease substrate specificities suggest that GBV-B may be useful in testing antiviral compounds for activity against HCV. Although there are numerous similarities between GBV-B and HCV, there are important differences in that HCV frequently causes chronic infections in people, whereas GBV-B appears to cause only acute infections. The acute versus chronic course of infection may point to important differences between the two viruses that, along with the numerous similarities, will make GBV-B in tamarins a good surrogate model for HCV.

Infectious cDNA clone of the hepatitis C virus genotype 1 prototype sequence

A full-length cDNA clone of the hepatitis C virus (HCV) genotype 1 prototype (subtype 1a) sequence was constructed. Synthetic RNA produced from the initial cDNA clone was not infectious following intrahepatic inoculation of a chimpanzee. A consensus clone was prepared by comparison with multiple full-length HCV sequences of genotypes 1, 2 and 3. A total of 11 non-consensus amino acid residues were altered by mutagenesis. Synthetic RNA from the repaired clone initiated a typical, acute-resolving HCV infection following intrahepatic inoculation of a chimpanzee. In addition, at least one of three chimeric cDNA clones constructed between the HCV-1 and H77 genotype 1a strains of HCV was infectious in a chimpanzee. This is the first example of an infectious chimeric HCV clone. An infectious cDNA clone of HCV-1 will be of particular value, since it is the prototype HCV sequence and many commonly used reagents are based on this sequence.

Oculo-palatal-cerebral syndrome: a second case

Oculo-palato-cerebral syndrome is an extremely rare disorder consisting of low birth weight, microcephaly, short stature, persistent hyperplastic primary vitreous, microphthalmia, large ears, small hands and feet, cleft palate, joint hypermobility, developmental delay, and cerebral atrophy. There has been one report of a consanguineous family with three affected children, suggesting autosomal recessive inheritance. We report on the second case of this disorder. Our patient, a 2-year-old boy, had growth delay, microcephaly, bilateral persistent hyperplastic primary vitreous with right microphthalmia, long ears with thickened helices, small hands and feet, highly arched palate, joint hypermobility, hypoplastic nails, frontal cerebral atrophy and thinning of the corpus callosum on brain magnetic resonance imaging, and mild developmental delay. He has much milder features than those seen in the previously reported cases.

Development of a primary tamarin hepatocyte culture system for GB virus-B: a surrogate model for hepatitis C virus

GB virus-B (GBV-B) causes an acute hepatitis in tamarins characterized by increased alanine transaminase levels that quickly return to normal as the virus is cleared. Phylogenetically, GBV-B is the closest relative to hepatitis C virus (HCV), and thus GBV-B infection of tamarins represents a powerful surrogate model system for the study of HCV. In this study, the course of infection of GBV-B in tamarins was followed using a real-time 5' exonuclease (TaqMan) reverse transcription-PCR assay to determine the level of GBV-B in the serum. Peak viremia levels exceeded 10(9) genome equivalents/ml, followed by viral clearance within 14 to 16 weeks. Rechallenge of animals that had cleared infection resulted in viremia that was limited to 1 week, suggestive of a strong protective immune response. A robust tissue culture system for GBV-B was developed using primary cultures of tamarin hepatocytes. Hepatocytes obtained from a GBV-B-infected animal maintained high levels of cell-associated viral RNA and virion secretion for 42 days of culture. In vitro infection of normal hepatocytes resulted in rapid amplification of cell-associated viral RNA and secretion of up to 10(7) genome equivalents/ml of culture supernatant. In addition, infection could be monitored by immunofluorescence staining for GBV-B nonstructural NS3 protein. This model system overcomes many of the current obstacles to HCV research, including low levels of viral replication, lack of a small primate animal model, and lack of a reproducible tissue culture system.

Hepadnavirus infection in captive gibbons

The recent isolation of a nonhuman primate hepadnavirus from woolly monkeys prompted an examination of other primates for potentially new hepadnaviruses. A serological analysis of 30 captive gibbons revealed that 47% were positive for at least one marker of ongoing or previous infection with a hepatitis B virus (HBV). The amino acid sequences of the core and surface genes of human and gibbon virus isolates were very similar. Phylogenetic analysis indicated that the gibbon isolates lie within the human HBV family, indicating that these HBV isolates most likely stem from infection of gibbons from a human source.

Attaining health for all through community partnerships: principles of the census-based, impact-oriented (CBIO) approach to primary health care developed in Bolivia, South America

This article describes a flexible primary health care methodology which was developed by Andean Rural Health Care and its colleagues in Bolivia, South America. This methodology, the census-based, impact-oriented (CBIO) approach to primary health care, involves determining local health priorities as defined both by locally acquired epidemiologic information and by the local people themselves. The CBIO approach to primary health care is now functioning successfully at seven program sites in Bolivia, which together serve 75,000 people in urban and rural communities in three distinct cultural and ecological regions of the country. High levels of coverage of basic health services can be achieved through a system of 'epidemographic' surveillance of all families and through home delivery, when needed, of priority services to those at risk. When the services provided are based on local health priorities, when they are provided in a technically effective manner, and when the community has a strong partnership in planning, implementation and evaluation, then the CBIO approach to primary health care will lead to measurable health improvements as defined by changes in population-based rates of mortality and illness in the community. On the basis of our experience, we believe that the CBIO approach offers great potential for strengthening the effectiveness of local health programs in impoverished communities around the world in a way which fosters community ownership and, hence, long-term sustainability.

Diarrhoea prevention in Bolivia through point-of-use water treatment and safe storage: a promising new strategy

A novel water quality intervention that consists of point-of-use water disinfection, safe storage and community education was field tested in Bolivia. A total of 127 households in two periurban communities were randomized into intervention and control groups, surveyed and the intervention was distributed. Monthly water quality testing and weekly diarrhoea surveillance were conducted. Over a 5-month period, intervention households had 44% fewer diarrhoea episodes than control households (P = 0.002). Infants < 1 year old (P = 0.05) and children 5-14 years old (P = 0.01) in intervention households had significantly less diarrhoea than control children. Campylobacter was less commonly isolated from intervention than control patients (P = 0.02). Stored water in intervention households was less contaminated with Escherichia coli than stored water in control households (P < 0.0001). Intervention households exhibited less E. coli contamination of stored water and less diarrhoea than control households. This promising new strategy may have broad applicability for waterborne disease prevention.

Academic models for practice relief, recruitment, and retention at the University of New Mexico Medical Center and East Carolina University School of Medicine

Locum tenens programs were independently developed by the University of New Mexico Health Sciences Center and East Carolina University School of Medicine to address health care needs within their states. The programs represent distinct models to provide locum tenens services for practices in rural and medically underserved regions through collaboration with stage government representatives and agencies. Differences between programs include years of operation, days of coverage provided, types of learners and providers involved, sources of funding, costs of the programs, and extent of institutional support. Common beneficial outcomes of the programs include coverage for struggling practices, training in rural medicine for locum tenens providers, recruitment of physicians to rural practice sites, and improved relationships with program partners. Adequate funding and institutional support are essential for success of locum tenens programs.

The census-based, impact-oriented approach: its effectiveness in promoting child health in Bolivia

This paper describes the effectiveness for child health of a primary health care approach developed in Bolivia by Andean Rural Health Care and its colleagues, the census-based, impact-oriented (CBIO) approach. Here, we describe selected achievements, including child survival service coverage, mortality impact, and the level of resources required to attain these results. As a result of first identifying the entire programme population through visits at least biannually to all homes and then targeting selected high-impact services to those at highest risk of death, the mortality levels of children under five years of age in the established programme areas was one-third to one-half of mortality levels in comparison areas. Card-documented coverage for the complete series of all the standard six childhood immunizations among children 12-23 months of age was 78%, and card-documented coverage for three nutritional monitorings during the previous 12 months among the same group of children was 80%. Coverage rates in comparison areas for similar services was less than 21%. The local annual recurring cost of this approach was US $8.57 for each person (of all ages) in the programme population. This cost includes the provision of primary care services for all age groups as well as targeted child survival services. This cost is well within the affordable range for many, if not most, developing countries. Manpower costs for field staff in Bolivia are relatively high, so in countries with lower salary scales, the overall recurring cost could be substantially less. An Expert Review Panel reviewed the CBIO approach and found it to be worthy of replication, particularly if stronger community involvement and greater reliance on volunteer or minimally paid staff could be attained. The results of this approach are sufficiently promising to merit implementation and evaluation in other sites, including sites beyond Bolivia.

Isolation of a hepadnavirus from the woolly monkey, a New World primate

Hepatitis B virus (HBV) infections are a major worldwide health problem with chronic infections leading to cirrhosis and liver cancer. Viruses related to human HBV have been isolated from birds and rodents, but despite efforts to find hepadnaviruses that infect species intermediate in evolution between rodents and humans, none have been described. We recently isolated a hepadnavirus from a woolly monkey (Lagothrix lagotricha) that was suffering from fulminant hepatitis. Phylogenetic analysis of the nucleotide sequences of the core and surface genes indicated that the virus was distinct from the human HBV family, and because it is basal (ancestral) to the human monophyletic group, it probably represents a progenitor of the human viruses. This virus was designated woolly monkey hepatitis B virus (WMHBV). Analysis of woolly monkey colonies at five zoos indicated that WMHBV infections occurred in most of the animals at the Louisville zoo but not at four other zoos in the United States. The host range of WMHBV was examined by inoculation of one chimpanzee and two black-handed spider monkeys (Ateles geoffroyi), the closest nonendangered relative of the woolly monkey. The data suggest that spider monkeys are susceptible to infection with WMHBV and that minimal replication was observed in a chimpanzee. Thus, we have isolated a hepadnavirus with a host intermediate between humans and rodents and establishes a new animal model for evaluation of antiviral therapies for treating HBV chronic infections.

Noninvasive comprehensive characterization of renal artery stenosis by combination of STAR angiography and EPISTAR perfusion imaging

In a small fraction of patients with hypertension, the cause is stenosis of the renal artery. To date, there is no established noninvasive screening technique available to identify this population, for whom treatment with a surgical procedure or percutaneous transluminal angioplasty is often possible. In this study, the sensitivity and specificity of STAR angiography and EPISTAR perfusion imaging in characterizing renal artery stenosis were evaluated in an animal model. Qualitatively, STAR provided projection angiograms that were comparably sensitive to x-ray angiograms but obtained noninvasively. The sensitivity for detecting the stenosis was 100%. The specificity varied according to the definition of the threshold for significance, which varied 78-94%, depending on whether > 70% or > 50% diameter reduction was considered. Improvements in specificity will depend upon use of shorter echo times and higher spatial resolution. Our preliminary data indicate that EPISTAR provides sensitivity and specificity of 100% for characterizing stenosis with diameter reductions of > 70%.

Magnetic resonance urography by breath-hold contrast-enhanced three-dimensional FISP

The purpose of this study was to present our initial experience with contrast-enhanced MR urography with a breath-hold three-dimensional imaging technique. We performed MR urographic studies in two pigs (four studies) and five human subjects using gadopentetate dimeglumine. The FISP sequence we used was the same as the one used for contrast-enhanced three-dimensional breath-hold angiography. MR three-dimensional urograms were obtained 7-24 minutes after the contrast injection with a dose as low as .03 mmol/kg. The calyces, renal pelves, and ureters were very well visualized. Three-dimensional MR urography can be acquired within a single breath-hold after administration of gadolinium chelates. This technique could become part of a protocol that could potentially lead to a single comprehensive diagnostic workup for suspected ureteral obstruction and gross hematuria.

Lack of susceptibility of baboons to infection with hepatitis B virus

Historically, hepatitis B virus (HBV) has been considered species specific and unable to infect baboons. Based on this premise, two patients with HBV endstage liver disease underwent baboon liver xenotransplantation. To study whether baboons are susceptible to HBV infection, four baboons (two receiving immunosuppressive therapy) were inoculated with HBV. Animals were followed for 6 months: clinical examinations and biochemical studies were normal, hepatitis B surface antigen and hepatitis B core antigen staining of biopsies was negative, and HBV serology remained negative. HBV polymerase chain reaction was transiently positive in one animal, which most likely reflects the initial inoculation. This pilot study corroborates historical evidence and beliefs that baboons are resistant to HBV.

Lack of detection of negative-strand hepatitis C virus RNA in peripheral blood mononuclear cells and other extrahepatic tissues by the highly strand-specific rTth reverse transcriptase PCR

To further explore the controversial potential for extrahepatic replication of hepatitis C virus (HCV), the highly strand-specific rTth method of reverse transcriptase PCR was used to examine sera, liver, peripheral blood mononuclear cells, and other extrahepatic tissues from HCV-infected chimpanzees and humans. Positive-strand HCV RNA was present in the liver at approximately 10-fold-higher levels than negative-strand HCV RNA. No negative-strand RNA was detected in peripheral blood mononuclear cells or other extrahepatic tissues despite the presence of abundant positive-strand RNA. These data demonstrate that within the limits of sensitivity of this highly strand-specific reverse transcriptase PCR method, no extrahepatic replication of HCV was detected.

Persistence of extrahepatic hepatitis B virus DNA in the absence of detectable hepatic replication in patients with baboon liver transplants

The presence of hepatitis B virus (HBV) DNA in extrahepatic tissues has been well documented. Whether HBV DNA can persist in extrahepatic tissues for long periods of time in the absence of replication in the liver has not been determined previously. Recently, two patients with end-stage liver disease secondary to chronic active HBV were treated with baboon liver xenotransplants as these animals are felt to be resistant to HBV infection. Multiple tissues from these two patients were examined for HBV DNA using polymerase chain reaction (PCR). HBV DNA was not detectable in four of five samples of the liver xenografts. A positive signal was observed in a single assay for one sample, but this sample was not positive in subsequent assays. HBV DNA was detected in peripheral blood lymphocytes, spleen, kidney, bone marrow, pancreas, lymph node, heart and small intestine. The level of HBV DNA in these tissues was too low for the detection of HBV DNA replicative intermediates by Southern hybridization; thus, it could not be determined whether the HBV DNA in these tissues represented actively replicating HBV in extrahepatic sites, integrated HBV sequences, HBV in infiltrating lymphocytes, or deposition of HBV immune complexes originating from the plasma. However, it is clear from this study that HBV DNA persisted in multiple tissues for 70 days after replication in the liver had ceased or at least was below the level of detection by PCR.

Analysis of hepatitis C virus capsid, E1, and E2/NS1 proteins expressed in insect cells

The baculovirus/insect cell expression system was used to express the capsid protein and glycoproteins (e1 and e2/NS1) of the hepatitis C virus (HCV). Each polypeptide domain was expressed individually using two different constructs varying at their carboxy termini in order to retain or delete hydrophobic domains that may be involved in membrane association. The capsid proteins were transported to the nucleus where they formed a single large crystal-like inclusion. The capsid proteins were phosphorylated in insect cells. The e1 and e2 polypeptides were present in both the soluble and insoluble cellular fractions. Deletion of a hydrophobic domain in the carboxy terminus of e2 resulted in the polypeptide becoming soluble but not secreted. Deletion of the carboxy terminus of e1 had no effect on solubility. Both e1 and e2 were glycosylated, with variable glycosylation of e1 giving rise to a series of polypeptides varying in apparent molecular weight. Co-infection of insect cells with viruses expressing e1 and e2 resulted in a complex that permitted the coimmunoprecipitation of e1 with antibodies to e2 and vice versa. Immunofluorescence staining of insect cells expressing e1 and e2 indicated that reactivity to e2 was more prevalent in anti-HCV positive human sera.