Pathogenesis of Rift Valley Fever Virus in a BALB/c Mouse Model Is Affected by Virus Culture Conditions and Sex of the Animals

Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic pathogen causing disease in livestock and humans. Whilst initially restricted to the African continent, recent spread to the Arabian Peninsula has highlighted the likelihood of entry into new regions. Due to the absence of a regulatory-approved human vaccine, work is ongoing to develop and assess countermeasures. As such, small animal models play a pivotal role in providing information on disease pathogenesis and elucidating which intervention strategies confer protection. To develop and establish the BALB/c mouse model, we challenged mice with RVFV grown from two separate cell lines: one derived from mosquitoes (C6/36) and the other mammalian derived (Vero E6). Following infection, we assessed the clinical course of disease progression at days 1 and 3 post-challenge and evaluated viral tropism and immune analytes. The results demonstrated that RVFV infection was affected by the cell line used to propagate the challenge virus, with those grown in insect cells resulting in a more rapid disease progression. The lowest dose that caused uniform severe disease remained the same across both virus preparations. In addition, to demonstrate reproducibility, the lowest dose was used for a subsequent infection study using male and female animals. The results further demonstrated that male mice succumbed to infection more rapidly than their female counterparts. Our results establish an RVFV mouse model and key parameters that affect the course of disease progression in BALB/c mice.

Comparative pathology of experimental pulmonary tuberculosis in animal models

Research in human tuberculosis (TB) is limited by the availability of human tissues from patients, which is often altered by therapy and treatment. Thus, the use of animal models is a key tool in increasing our understanding of the pathogenesis, disease progression and preclinical evaluation of new therapies and vaccines. The granuloma is the hallmark lesion of pulmonary tuberculosis, regardless of the species or animal model used. Although animal models may not fully replicate all the histopathological characteristics observed in natural, human TB disease, each one brings its own attributes which enable researchers to answer specific questions regarding TB immunopathogenesis. This review delves into the pulmonary pathology induced by Mycobacterium tuberculosis complex (MTBC) bacteria in different animal models (non-human primates, rodents, guinea pigs, rabbits, cattle, goats, and others) and compares how they relate to the pulmonary disease described in humans. Although the described models have demonstrated some histopathological features in common with human pulmonary TB, these data should be considered carefully in the context of this disease. Further research is necessary to establish the most appropriate model for the study of TB, and to carry out a standard characterisation and score of pulmonary lesions.

Spore-FP1 tuberculosis mucosal vaccine candidate is highly protective in guinea pigs but fails to improve on BCG-conferred protection in non-human primates

Tuberculosis remains a major health threat globally and a more effective vaccine than the current Bacillus Calmette Guerin (BCG) is required, either to replace or boost it. The Spore-FP1 mucosal vaccine candidate is based on the fusion protein of Ag85B-Acr-HBHA/heparin-binding domain, adsorbed on the surface of inactivated Bacillus subtilis spores. The candidate conferred significant protection against Mycobacterium. tuberculosis challenge in naïve guinea pigs and markedly improved protection in the lungs and spleens of animals primed with BCG. We then immunized rhesus macaques with BCG intradermally, and subsequently boosted with one intradermal and one aerosol dose of Spore-FP1, prior to challenge with low dose aerosolized M. tuberculosis Erdman strain. Following vaccination, animals did not show any adverse reactions and displayed higher antigen specific cellular and antibody immune responses compared to BCG alone but this did not translate into significant improvement in disease pathology or bacterial burden in the organs.

Characterisation and development of histopathological lesions in a guinea pig model of Mycobacterium tuberculosis infection

Tuberculosis (TB) remains a very significant infectious disease worldwide. New vaccines and therapies are needed, even more crucially with the increase of multi-drug resistant Mycobacterium tuberculosis strains. Preclinical animal models are very valuable for the development of these new disease control strategies. Guinea pigs are one of the best models of TB, sharing many features with the pathology observed in human TB. Here we describe the development of TB lesions in a guinea pig model of infection. We characterise the granulomatous lesions in four developmental stages (I-IV), using histopathological analysis and immunohistochemical (IHC) techniques to study macrophages, T cells, B cells and granulocytes. The granulomas in the guinea pigs start as aggregations of macrophages and few heterophils, evolving to larger lesions showing central caseous necrosis with mineralisation and abundant acid-fast bacilli, surrounded by a rim of macrophages and lymphocytes in the outer layers of the granuloma. Multinucleated giant cells are very rare and fibrotic capsules are not formed in this animal model.

Refinement of an ovine-based immunoglobulin therapy against SARS-CoV-2, with comparison of whole IgG versus F(ab')2 fragments

The development of new therapies against SARS-CoV-2 is required to extend the toolkit of intervention strategies to combat the global pandemic. In this study, hyperimmune plasma from sheep immunised with whole spike SARS-CoV-2 recombinant protein has been used to generate candidate products. In addition to purified IgG, we have refined candidate therapies by removing non-specific IgG via affinity binding along with fragmentation to eliminate the Fc region to create F(ab')2 fragments. These preparations were evaluated for in vitro activity and demonstrated to be strongly neutralising against a range of SARS-CoV-2 strains, including Omicron B2.2. In addition, their protection against disease manifestations and viral loads were assessed using a hamster SARS-CoV-2 infection model. Results demonstrated protective effects of both IgG and F(ab')2, with the latter requiring sequential dosing to maintain in vivo activity due to rapid clearance from the circulation.

Adenoviral vectored vaccination protects against Crimean-Congo Haemorrhagic Fever disease in a lethal challenge model

BACKGROUND

The tick-borne bunyavirus, Crimean-Congo Haemorrhagic Fever virus (CCHFV), can cause severe febrile illness in humans and has a wide geographic range that continues to expand due to tick migration. Currently, there are no licensed vaccines against CCHFV for widespread usage.

METHODS

In this study, we describe the preclinical assessment of a chimpanzee adenoviral vectored vaccine (ChAdOx2 CCHF) which encodes the glycoprotein precursor (GPC) from CCHFV.

FINDINGS

We demonstrate here that vaccination with ChAdOx2 CCHF induces both a humoral and cellular immune response in mice and 100% protection in a lethal CCHF challenge model. Delivery of the adenoviral vaccine in a heterologous vaccine regimen with a Modified Vaccinia Ankara vaccine (MVA CCHF) induces the highest levels of CCHFV-specific cell-mediated and antibody responses in mice. Histopathological examination and viral load analysis of the tissues of ChAdOx2 CCHF immunised mice reveals an absence of both microscopic changes and viral antigen associated with CCHF infection, further demonstrating protection against disease.

INTERPRETATION

There is the continued need for an effective vaccine against CCHFV to protect humans from lethal haemorrhagic disease. Our findings support further development of the ChAd platform expressing the CCHFV GPC to seek an effective vaccine against CCHFV.

FUNDING

This research was supported by funding from the Biotechnology and Biological Sciences Research Council (UKRI-BBSRC) [BB/R019991/1 and BB/T008784/1].

Sharing the Load by One Health: Integrating Canine Rabies Vaccination With Bovine Foot-and-Mouth Vaccination Program and Community Public Health Services in Rural Nilgiris District, Tamil Nadu, India

Background

India carries the largest national burden for rabies globally. Coordinating large-scale canine rabies elimination programs is challenging, particularly in rural areas, where the majority of human rabies deaths occur. This study evaluated the feasibility of combining canine rabies vaccination with pre-existing animal-health interventions or public health programs in a rural area of India.

Materials and Methods

Canine rabies vaccination teams collaborated with a bi-annual bovine foot-and-mouth vaccination program coordinated by the Animal Husbandry Department (AH-collaboration) and with a village health program by the Public Health Department (PH-collaboration) in Nilgiris, Tamil Nadu, to vaccinate dogs during the implementation of these government-led health initiatives.

Results

A total of 251 dogs were vaccinated over 7 days during the AH-collaboration, and 1083 dogs were vaccinated over 15 days during the PH-collaboration. The AH-collaboration achieved a vaccination coverage of 76% based on same-time sighting survey, and 58% based on post-vaccination survey. The PH-collaboration achieved vaccination coverage of 79% based on the same-time survey and 83% based on the post-vaccination survey.

Conclusions

The integration of mass dog vaccination into existing government sector initiatives may facilitate the scaling up of canine rabies vaccination campaigns.

Development of a cost-effective ovine antibody-based therapy against SARS-CoV-2 infection and contribution of antibodies specific to the spike subunit proteins

Antibodies against SARS-CoV-2 are important to generate protective immunity, with convalescent plasma one of the first therapies approved. An alternative source of polyclonal antibodies suitable for upscaling would be more amendable to regulatory approval and widespread use. In this study, sheep were immunised with SARS-CoV-2 whole spike protein or one of the subunit proteins: S1 and S2. Once substantial antibody titres were generated, plasma was collected and samples pooled for each antigen. Non-specific antibodies were removed via affinity-purification to yield candidate products for testing in a hamster model of SARS-CoV-2 infection. Affinity-purified polyclonal antibodies to whole spike, S1 and S2 proteins were evaluated for in vitro for neutralising activity against SARS-CoV-2 Wuhan-like virus (Australia/VIC01/2020) and a recent variant of concern, B.1.1.529 BA.1 (Omicron), antibody-binding, complement fixation and phagocytosis assays were also performed. All antibody preparations demonstrated an effect against SARS-CoV-2 disease in the hamster model of challenge, with those raised against the S2 subunit providing the most promise. A rapid, cost-effective therapy for COVID-19 was developed which provides a source of highly active immunoglobulin specific to SARS-CoV-2 with multi-functional activity.

Influence of Aerosol Delivered BCG Vaccination on Immunological and Disease Parameters Following SARS-CoV-2 Challenge in Rhesus Macaques

The tuberculosis vaccine, Bacille Calmette-Guerin (BCG), also affords protection against non-tuberculous diseases attributable to heterologous immune mechanisms such as trained innate immunity, activation of non-conventional T-cells, and cross-reactive adaptive immunity. Aerosol vaccine delivery can target immune responses toward the primary site of infection for a respiratory pathogen. Therefore, we hypothesised that aerosol delivery of BCG would enhance cross-protective action against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and be a deployable intervention against coronavirus disease 2019 (COVID-19). Immune parameters were monitored in vaccinated and unvaccinated rhesus macaques for 28 days following aerosol BCG vaccination. High-dose SARS-CoV-2 challenge was applied by intranasal and intrabronchial instillation and animals culled 6–8 days later for assessment of viral, disease, and immunological parameters. Mycobacteria-specific cell-mediated immune responses were detected following aerosol BCG vaccination, but SARS-CoV-2-specific cellular- and antibody-mediated immunity was only measured following challenge. Early secretion of cytokine and chemokine markers associated with the innate cellular and adaptive antiviral immune response was detected following SARS-CoV-2 challenge in vaccinated animals, at concentrations that exceeded titres measured in unvaccinated macaques. Classical CD14+ monocytes and Vδ2 γδ T-cells quantified by whole-blood immunophenotyping increased rapidly in vaccinated animals following SARS-CoV-2 challenge, indicating a priming of innate immune cells and non-conventional T-cell populations. However, viral RNA quantified in nasal and pharyngeal swabs, bronchoalveolar lavage (BAL), and tissue samples collected at necropsy was equivalent in vaccinated and unvaccinated animals, and in-life CT imaging and histopathology scoring applied to pulmonary tissue sections indicated that the disease induced by SARS-CoV-2 challenge was comparable between vaccinated and unvaccinated groups. Hence, aerosol BCG vaccination did not induce, or enhance the induction of, SARS-CoV-2 cross-reactive adaptive cellular or humoral immunity, although an influence of BCG vaccination on the subsequent immune response to SARS-CoV-2 challenge was apparent in immune signatures indicative of trained innate immune mechanisms and primed unconventional T-cell populations. Nevertheless, aerosol BCG vaccination did not enhance the initial clearance of virus, nor reduce the occurrence of early disease pathology after high dose SARS-CoV-2 challenge. However, the heterologous immune mechanisms primed by BCG vaccination could contribute to the moderation of COVID-19 disease severity in more susceptible species following natural infection.

Finafloxacin, a Novel Fluoroquinolone, Reduces the Clinical Signs of Infection and Pathology in a Mouse Model of Q Fever

Finafloxacin is a novel fluoroquinolone with optimal antibacterial activity in low pH environments, therefore offering a therapeutic advantage over some traditional antibiotics, in treating bacterial infections associated with acidic foci. Coxiella burnetii, the causative agent of Q fever, is a bacterium which resides and replicates in acidic intracellular parasitic vacuoles. The efficacy of finafloxacin was evaluated in vivo using the A/J mouse model of inhalational Q fever and was compared to doxycycline, the standard treatment for this infection and ciprofloxacin, a comparator fluoroquinolone. Finafloxacin reduced the severity of the clinical signs of infection and weight loss associated with Q fever, but did not reduce the level of bacterial colonization in tissues compared to doxycycline or ciprofloxacin. However, histopathological analysis suggested that treatment with finafloxacin reduced tissue damage associated with C. burnetii infection. In addition, we report for the first time, the use of viable counts on axenic media to evaluate antibiotic efficacy in vivo.

Sequential delivery of LAIV and SARS-CoV-2 in the ferret model can reduce SARS-CoV-2 shedding and does not result in enhanced lung pathology

Co-circulation of SARS-CoV-2 and influenza viruses could pose unpredictable risks to health systems globally, with recent studies suggesting more severe disease outcomes in co-infected patients. The initial lack of a readily available COVID-19 vaccine has reinforced the importance of influenza vaccine programmes during the COVID-19 pandemic. Live Attenuated Influenza Vaccine (LAIV) is an important tool in protecting against influenza, particularly in children. However, it is unknown whether LAIV administration influences the outcomes of acute SARS-CoV-2 infection or disease. To investigate this, quadrivalent LAIV was administered to ferrets 3 days pre- or post-SARS-CoV-2 infection. LAIV administration did not exacerbate SARS-CoV-2 disease course or lung pathology with either regimen. Additionally, LAIV administered prior to SARS-CoV-2 infection significantly reduced SARS-CoV-2 replication and shedding in the upper respiratory tract. This study demonstrated that LAIV administration in close proximity to SARS-CoV-2 infection does not exacerbate mild disease and can reduce SARS-CoV-2 shedding.

Immunological and pathological outcomes of SARS-CoV-2 challenge following formalin-inactivated vaccine in ferrets and rhesus macaques

There is an urgent requirement for safe and effective vaccines to prevent COVID-19. A concern for the development of new viral vaccines is the potential to induce vaccine-enhanced disease (VED). This was reported in several preclinical studies with both SARS-CoV-1 and MERS vaccines but has not been reported with SARS-CoV-2 vaccines. We have used ferrets and rhesus macaques challenged with SARS-CoV-2 to assess the potential for VED in animals vaccinated with formaldehyde-inactivated SARS-CoV-2 (FIV) formulated with Alhydrogel, compared to a negative control vaccine. We showed no evidence of enhanced disease in ferrets or rhesus macaques given FIV except for mild transient enhanced disease seen 7 days after infection in ferrets. This increased lung pathology was observed at day 7 but was resolved by day 15. We also demonstrate that formaldehyde treatment of SARS-CoV-2 reduces exposure of the spike receptor binding domain providing a mechanistic explanation for suboptimal immunity.

One or two dose regimen of the SARS-CoV-2 synthetic DNA vaccine INO-4800 protects against respiratory tract disease burden in nonhuman primate challenge model

Safe and effective vaccines will provide essential medical countermeasures to tackle the COVID-19 pandemic. Here, we assessed the safety, immunogenicity and efficacy of the intradermal delivery of INO-4800, a synthetic DNA vaccine candidate encoding the SARS-CoV-2 spike protein in the rhesus macaque model. Single and 2 dose vaccination regimens were evaluated. Vaccination induced both binding and neutralizing antibodies, along with IFN-γ-producing T cells against SARS-CoV-2. Upon administration of a high viral dose (5 × 10⁶ pfu) via the intranasal and intratracheal routes we observed significantly reduced virus load in the lung and throat, in the vaccinated animals compared to controls. 2 doses of INO-4800 was associated with more robust vaccine-induced immune responses and improved viral protection. Importantly, histopathological examination of lung tissue provided no indication of vaccine-enhanced disease following SARS-CoV-2 challenge in INO-4800 immunized animals. This vaccine candidate is currently under clinical evaluation as a 2 dose regimen.

A randomised controlled clinical trial comparing the effectiveness of bandaging compared to the JuxtaCures™ device in the management of people with venous ulceration: Feasibility study

INTRODUCTION

The mainstay of treatment for venous ulceration remains compression therapy. Velcro Wrap devices are being increasingly used in these patients despite limited evidence. This feasibility study aimed to compare standard bandaging to the JuxtaCures™ Velcro wrap device.

METHODS

A single centre, unblinded RCT compared participants with venous ulceration randomised to either the JuxtaCures™ device or short stretch bandaging. Participants were followed up for 26 weeks.

RESULTS

160 participants were screened with 40 randomised. 3 participants in bandaging and 1 in JuxtaCures™ didn't complete the study. 60% in JuxtaCures™ healed v 55% in bandaging despite larger ulcers in the JuxtaCures™ arm (9.33 cm² v 6.97 cm²). There was no significant difference in time to healing (12.17 v 13.64 weeks). JuxtaCures™ showed improved ulcer reduction for those that didn't heal (14.91-5.00 cm² v 14.20-8.62 cm²; P = 0.06). JuxtaCures™ had more consistent sub-bandage pressure dropping from 39-36 mmHg versus 41-25 mmHg in bandaging between application and removal (P < 0.001). Quality of life (EQ5D) was improved in JuxtaCures at 3 months (mean difference 0.14, p = 0.04), but not at 1 and 6 months, or in disease specific quality of life. Cost was lower in JuxtaCures™ £842.47 v £1064.68. Duration of appointment was significantly shorter in JuxtaCures™ (41 minutes v 53 minutes; P = 0.003).

CONCLUSION

This study has shown the feasibility and necessity of running a multicentre trial to evaluate the use of Velcro wrap devices for venous ulceration. It highlights the potential benefits of more consistent pressure, increased self-care, and potential with regards to ulcer healing, cost, nursing resource and quality of life.

Prophylactic intranasal administration of a TLR2/6 agonist reduces upper respiratory tract viral shedding in a SARS-CoV-2 challenge ferret model

BACKGROUND

The novel human coronavirus SARS-CoV-2 is a major ongoing global threat with huge economic burden. Like all respiratory viruses, SARS-CoV-2 initiates infection in the upper respiratory tract (URT). Infected individuals are often asymptomatic, yet highly infectious and readily transmit virus. A therapy that restricts initial replication in the URT has the potential to prevent progression of severe lower respiratory tract disease as well as limiting person-to-person transmission.

METHODS

SARS-CoV-2 Victoria/01/2020 was passaged in Vero/hSLAM cells and virus titre determined by plaque assay. Challenge virus was delivered by intranasal instillation to female ferrets at 5.0 × 106 pfu/ml. Treatment groups received intranasal INNA-051, developed by Ena Respiratory. SARS-CoV-2 RNA was detected using the 2019-nCoV CDC RUO Kit and QuantStudio™ 7 Flex Real-Time PCR System. Histopathological analysis was performed using cut tissues stained with haematoxylin and eosin (H&E).

FINDINGS

We show that prophylactic intra-nasal administration of the TLR2/6 agonist INNA-051 in a SARS-CoV-2 ferret infection model effectively reduces levels of viral RNA in the nose and throat. After 5 days post-exposure to SARS-CoV-2, INNA-051 significantly reduced virus in throat swabs (p=<0.0001) by up to a 24 fold (96% reduction) and in nasal wash (p=0.0107) up to a 15 fold (93% reduction) in comparison to untreated animals.

INTERPRETATION

The results of our study support clinical development of a therapy based on prophylactic TLR2/6 innate immune activation in the URT, to reduce SARS-CoV-2 transmission and provide protection against COVID-19.

FUNDING

This work was funded by Ena Respiratory, Melbourne, Australia.

Therapeutic Monoclonal Antibodies for Ebola Virus Infection Derived from Vaccinated Humans

We describe therapeutic monoclonal antibodies isolated from human volunteers vaccinated with recombinant adenovirus expressing Ebola virus glycoprotein (EBOV GP) and boosted with modified vaccinia virus Ankara. Among 82 antibodies isolated from peripheral blood B cells, almost half neutralized GP pseudotyped influenza virus. The antibody response was diverse in gene usage and epitope recognition. Although close to germline in sequence, neutralizing antibodies with binding affinities in the nano- to pico-molar range, similar to "affinity matured" antibodies from convalescent donors, were found. They recognized the mucin-like domain, glycan cap, receptor binding region, and the base of the glycoprotein. A cross-reactive cocktail of four antibodies, targeting the latter three non-overlapping epitopes, given on day 3 of EBOV infection, completely protected guinea pigs. This study highlights the value of experimental vaccine trials as a rich source of therapeutic human monoclonal antibodies.

Protective Efficacy of Inhaled BCG Vaccination Against Ultra-Low Dose Aerosol M. tuberculosis Challenge in Rhesus Macaques

Ten million cases of tuberculosis (TB) were reported in 2018 with a further 1.5 million deaths attributed to the disease. Improved vaccination strategies are urgently required to tackle the ongoing global TB epidemic. In the absence of a validated correlate of protection, highly characterised pre-clinical models are required to assess the protective efficacy of new vaccination strategies. In this study, we demonstrate the application of a rhesus macaque ultra-low dose (ULD) aerosol M. tuberculosis challenge model for the evaluation of TB vaccination strategies by directly comparing the immunogenicity and efficacy of intradermal (ID) and aerosol BCG vaccination delivered using a portable vibrating mesh nebulizer (VMN). Aerosol- and ID-delivered Bacille Calmette-Guérin (BCG) induced comparable frequencies of IFN-γ spot forming units (SFU) measured in peripheral blood mononuclear cells (PBMCs) by ELISpot, although the induction of IFN-γ SFU was significantly delayed following aerosol immunisation. This delayed response was also apparent in an array of secreted pro-inflammatory and chemokine markers, as well as in the frequency of antigen-specific cytokine producing CD4 and CD8 T-cells measured by multi-parameter flow cytometry. Interrogation of antigen-specific memory T-cell phenotypes revealed that vaccination-induced CD4 and CD8 T-cell populations primarily occupied the central memory (TCM) and transitional effector memory (TransEM) phenotype, and that the frequency of CD8 TCM and TransEM populations was significantly higher in aerosol BCG-vaccinated animals in the week prior to M. tuberculosis infection. The total and lung pathology measured following M. tuberculosis challenge was significantly lower in vaccinated animals relative to the unvaccinated control group and pathology measured in extra-pulmonary tissues was significantly reduced in aerosol BCG-vaccinated animals, relative to the ID-immunised group. Similarly, significantly fewer viable M. tuberculosis CFU were recovered from the extra-pulmonary tissues of aerosol BCG-vaccinated macaques relative to unvaccinated animals. In this study, a rhesus macaque ULD M. tuberculosis aerosol challenge model was applied as a refined and sensitive system for the evaluation of TB vaccine efficacy and to confirm that aerosol BCG vaccination delivered by portable VMN can confer a significant level of protection that is equivalent, and by some measures superior, to intradermal BCG vaccination.

Prevalence of skin wounds in working donkeys in Bukombe, Tanzania

BACKGROUND

Preventable wounds are a common welfare issue in working donkeys in many countries. In the Bukombe District of Tanzania, there are estimated to be 3000 working donkeys, used primarily to transport loads for direct income generation. For historical reasons, oxen-yoke carts are used; their design is inappropriate for donkeys and results in serious neck wounds. The project aim was to assess the prevalence and nature of wounds in working donkeys.

METHODS

In November 2018, 148 donkeys owned by 48 owners were examined, and data were collected.

RESULTS

The study revealed that one or more wounds were present in 56.1% of the population and yoke-related, dorsal neck wounds comprised 79.5% of these. These wounds ranged in surface area from 1 cm² to 300 cm². Clinically, 96.6% of all wound types were superficial and the majority of these (51.1%) were granulating.

CONCLUSION

These data will enable the future evaluation of targeted interventions aimed at reducing the prevalence of these specific wounds.

Lineage-dependent differences in the disease progression of Zika virus infection in type-I interferon receptor knockout (A129) mice

Zika virus (ZIKV) falls into two lineages: African (ZIKVAF) and Asian (ZIKVAS). These lineages have not been tested comprehensively in parallel for disease progression using an animal model system. Here, using the established type-I interferon receptor knockout (A129) mouse model, it is first demonstrated that ZIKVAF causes lethal infection, with different kinetics of disease manifestations according to the challenge dose. Animals challenged with a low dose of 10 plaque-forming units (pfu) developed more neurological symptoms than those challenged with 5-log higher doses. By contrast, animals challenged with ZIKVAS displayed no clinical signs or mortality, even at doses of 106 pfu. However, viral RNA was detected in the tissues of animals infected with ZIKV strains from both lineages and similar histological changes were observed. The present study highlights strain specific virulence differences between the African and Asian lineages in a ZIKV mouse model.

Post-exposure treatment of non-human primates lethally infected with Ebola virus with EBOTAb, a purified ovine IgG product

Despite sporadic outbreaks of Ebola virus (EBOV) over the last 4 decades and the recent public health emergency in West Africa, there are still no approved vaccines or therapeutics for the treatment of acute EBOV disease (EVD). In response to the 2014 outbreak, an ovine immunoglobulin therapy was developed, termed EBOTAb. After promising results in the guinea pig model of EBOV infection, EBOTAb was tested in the cynomolgus macaque non-human primate model of lethal EBOV infection. To ensure stringent therapeutic testing conditions to replicate likely clinical usage, EBOTAb was first delivered 1, 2 or 3 days post-challenge with a lethal dose of EBOV. Results showed a protective effect of EBOTAb given post-exposurally, with survival rates decreasing with increasing time after challenge. Viremia results demonstrated that EBOTAb resulted in a decreased circulation of EBOV in the bloodstream. Additionally, assay of liver enzymes and histology analysis of local tissues identified differences between EBOTAb-treated and untreated groups. The results presented demonstrate that EBOTAb conferred protection against EBOV when given post-exposure and should be explored and developed further as a potential intervention strategy for future outbreaks, which are likely to occur.

A Crimean-Congo hemorrhagic fever (CCHF) viral vaccine expressing nucleoprotein is immunogenic but fails to confer protection against lethal disease

Crimean-Congo Hemorrhagic Fever (CCHF) is a severe tick-borne disease, endemic in many countries in Africa, the Middle East, Eastern Europe and Asia. Between 15–70% of reported cases are fatal with no approved vaccine available. In the present study, the attenuated poxvirus vector, Modified Vaccinia virus Ankara, was used to develop a recombinant candidate vaccine expressing the CCHF virus nucleoprotein. Cellular and humoral immunogenicity was confirmed in 2 mouse strains, including type I interferon receptor knockout mice, which are susceptible to CCHF disease. Despite the immune responses generated post-immunisation, the vaccine failed to protect animals from lethal disease in a challenge model.

Alternative BCG delivery strategies improve protection against Mycobacterium tuberculosis in non-human primates: Protection associated with mycobacterial antigen-specific CD4 effector memory T-cell populations

Intradermal (ID) BCG injection provides incomplete protection against TB in humans and experimental models. Alternative BCG vaccination strategies may improve protection in model species, including rhesus macaques. This study compares the immunogenicity and efficacy of BCG administered by ID and intravenous (IV) injection, or as an intratracheal mucosal boost (ID + IT), against aerosol challenge with Mycobacterium tuberculosis Erdman strain. Disease pathology was significantly reduced, and survival improved, by each BCG vaccination strategy, relative to unvaccinated animals. However, IV induced protection surpassed that achieved by all other routes, providing an opportunity to explore protective immunological mechanisms using antigen-specific IFN-γ ELISpot and polychromatic flow cytometry assays. IFN-γ spot forming units and multifunctional CD4 T-cell frequencies increased significantly following each vaccination regimen and were greatest following IV immunisation. Vaccine-induced multifunctional CD4 T-cells producing IFN-γ and TNF-α were associated with reduced disease pathology following subsequent M.tb challenge; however, high frequencies of this population following M.tb infection correlated with increased pathology. Cytokine producing T-cells primarily occupied the CD4 transitional effector memory phenotype, implicating this population as central to the mycobacterial response, potentially contributing to the stringent control observed in IV vaccinated animals. This study demonstrates the protective efficacy of IV BCG vaccination in rhesus macaques, offering a valuable tool for the interrogation of immunological mechanisms and potential correlates of protection.

Chloroquine inhibited Ebola virus replication in vitro but failed to protect against infection and disease in the in vivo guinea pig model

Ebola virus (EBOV) is highly pathogenic, with a predisposition to cause outbreaks in human populations accompanied by significant mortality. Owing to the lack of approved therapies, screening programmes of potentially efficacious drugs have been undertaken. One of these studies has demonstrated the possible utility of chloroquine against EBOV using pseudotyped assays. In mouse models of EBOV disease there are conflicting reports of the therapeutic effects of chloroquine. There are currently no reports of its efficacy using the larger and more stringent guinea pig model of infection. In this study we have shown that replication of live EBOV is impaired by chloroquine in vitro. However, no protective effects were observed in vivo when EBOV-infected guinea pigs were treated with chloroquine. These results advocate that chloroquine should not be considered as a treatment strategy for EBOV.

TNFα promotes CAR-dependent migration of leukocytes across epithelial monolayers

Trans-epithelial migration (TEpM) of leukocytes during inflammation requires engagement with receptors expressed on the basolateral surface of the epithelium. One such receptor is Coxsackie and Adenovirus Receptor (CAR) that binds to Junctional Adhesion Molecule-like (JAM-L) expressed on leukocytes. Here we provide the first evidence that efficient TEpM of monocyte-derived THP-1 cells requires and is controlled by phosphorylation of CAR. We show that TNFα acts in a paracrine manner on epithelial cells via a TNFR1-PI3K-PKCδ pathway leading to CAR phosphorylation and subsequent transmigration across cell junctions. Moreover, we show that CAR is hyper-phosphorylated in vivo in acute and chronic lung inflammation models and this response is required to facilitate immune cell recruitment. This represents a novel mechanism of feedback between leukocytes and epithelial cells during TEpM and may be important in controlling responses to pro-inflammatory cytokines in pathological settings.

A Susceptible Mouse Model for Zika Virus Infection

Zika virus (ZIKV) is a mosquito-borne pathogen which has recently spread beyond Africa and into Pacific and South American regions. Despite first being detected in 1947, very little information is known about the virus, and its spread has been associated with increases in Guillain-Barre syndrome and microcephaly. There are currently no known vaccines or antivirals against ZIKV infection. Progress in assessing interventions will require the development of animal models to test efficacies; however, there are only limited reports on in vivo studies. The only susceptible murine models have involved intracerebral inoculations or juvenile animals, which do not replicate natural infection. Our report has studied the effect of ZIKV infection in type-I interferon receptor deficient (A129) mice and the parent strain (129Sv/Ev) after subcutaneous challenge in the lower leg to mimic a mosquito bite. A129 mice developed severe symptoms with widespread viral RNA detection in the blood, brain, spleen, liver and ovaries. Histological changes were also striking in these animals. 129Sv/Ev mice developed no clinical symptoms or histological changes, despite viral RNA being detectable in the blood, spleen and ovaries, albeit at lower levels than those seen in A129 mice. Our results identify A129 mice as being highly susceptible to ZIKV and thus A129 mice represent a suitable, and urgently required, small animal model for the testing of vaccines and antivirals.

Development of a Cost-effective Ovine Polyclonal Antibody-Based Product, EBOTAb, to Treat Ebola Virus Infection

The highly glycosylated glycoprotein spike of Ebola virus (EBOV-GP1,2) is the primary target of the humoral host response. Recombinant EBOV-GP ectodomain (EBOV-GP1,2ecto) expressed in mammalian cells was used to immunize sheep and elicited a robust immune response and produced high titers of high avidity polyclonal antibodies. Investigation of the neutralizing activity of the ovine antisera in vitro revealed that it neutralized EBOV. A pool of intact ovine immunoglobulin G, herein termed EBOTAb, was prepared from the antisera and used for an in vivo guinea pig study. When EBOTAb was delivered 6 hours after challenge, all animals survived without experiencing fever or other clinical manifestations. In a second series of guinea pig studies, the administration of EBOTAb dosing was delayed for 48 or 72 hours after challenge, resulting in 100% and 75% survival, respectively. These studies illustrate the usefulness of EBOTAb in protecting against EBOV-induced disease.

Increased protective efficacy of recombinant BCG strains expressing virulence-neutral proteins of the ESX-1 secretion system

BACKGROUND

Mycobacterium bovis BCG is presently the only available anti-tuberculosis vaccine used, worldwide. While BCG protects against miliary tuberculosis (TB) and tuberculoid meningitis in children, it often fails to protect against adult pulmonary TB. It is thus imperative that new improved anti-TB vaccines are developed. The integration of the ESX-1 secretion system, absent from BCG due to the deletion of region of difference 1 (RD1), into the genome of BCG has been shown to confer to BCG::ESX-1 enhanced protection against TB as compared to BCG.

METHODS

In the present study, to counterbalance the increase in virulence resulting from the integration of the RD1 region into BCG, we have constructed and evaluated several BCG::ESX-1 variants that carry selected amino-acid changes in the ESX-1-secreted antigen ESAT-6. In order to find the candidate that combines low virulence with high protective efficacy, these novel recombinant BCG::ESX-1 strains were tested for their virulence properties and their protective efficacy against Mycobacterium tuberculosis in two different animal models (mouse and guinea-pig).

RESULTS

Among several candidates tested, the BCG::ESAT-L28A/L29S strain, carrying modifications at residues Leu(28)-Leu(29) of the ESAT molecule, showed strong attenuation in mice and high protective efficiency both in mouse and guinea-pig vaccination-infection models.

CONCLUSION

This strain thus represents a promising candidate that merits further investigations and development. Our research also provides the proof of concept that selected ESX-1-complemented BCG strains may show low virulence and increased protective potential over parental strains.

Sequence of pathogenic events in cynomolgus macaques infected with aerosolized monkeypox virus

To evaluate new vaccines when human efficacy studies are not possible, the FDA's "Animal Rule" requires well-characterized models of infection. Thus, in the present study, the early pathogenic events of monkeypox infection in nonhuman primates, a surrogate for variola virus infection, were characterized. Cynomolgus macaques were exposed to aerosolized monkeypox virus (10(5) PFU). Clinical observations, viral loads, immune responses, and pathological changes were examined on days 2, 4, 6, 8, 10, and 12 postchallenge. Viral DNA (vDNA) was detected in the lungs on day 2 postchallenge, and viral antigen was detected, by immunostaining, in the epithelium of bronchi, bronchioles, and alveolar walls. Lesions comprised rare foci of dysplastic and sloughed cells in respiratory bronchioles. By day 4, vDNA was detected in the throat, tonsil, and spleen, and monkeypox antigen was detected in the lung, hilar and submandibular lymph nodes, spleen, and colon. Lung lesions comprised focal epithelial necrosis and inflammation. Body temperature peaked on day 6, pox lesions appeared on the skin, and lesions, with positive immunostaining, were present in the lung, tonsil, spleen, lymph nodes, and colon. By day 8, vDNA was present in 9/13 tissues. Blood concentrations of interleukin 1ra (IL-1ra), IL-6, and gamma interferon (IFN-γ) increased markedly. By day 10, circulating IgG antibody concentrations increased, and on day 12, animals showed early signs of recovery. These results define early events occurring in an inhalational macaque monkeypox infection model, supporting its use as a surrogate model for human smallpox.

IMPORTANCE

Bioterrorism poses a major threat to public health, as the deliberate release of infectious agents, such smallpox or a related virus, monkeypox, would have catastrophic consequences. The development and testing of new medical countermeasures, e.g., vaccines, are thus priorities; however, tests for efficacy in humans cannot be performed because it would be unethical and field trials are not feasible. To overcome this, the FDA may grant marketing approval of a new product based upon the "Animal Rule," in which interventions are tested for efficacy in well-characterized animal models. Monkeypox virus infection of nonhuman primates (NHPs) presents a potential surrogate disease model for smallpox. Previously, the later stages of monkeypox infection were defined, but the early course of infection remains unstudied. Here, the early pathogenic events of inhalational monkeypox infection in NHPs were characterized, and the results support the use of this surrogate model for testing human smallpox interventions.

A novel vaccine against Crimean-Congo Haemorrhagic Fever protects 100% of animals against lethal challenge in a mouse model

Crimean-Congo Haemorrhagic Fever (CCHF) is a severe tick-borne disease, endemic in many countries in Africa, the Middle East, Eastern Europe and Asia. Between 15-70% of reported cases are fatal. There is no approved vaccine available, and preclinical protection in vivo by an experimental vaccine has not been demonstrated previously. In the present study, the attenuated poxvirus vector, Modified Vaccinia virus Ankara, was used to develop a recombinant candidate vaccine expressing the CCHF virus glycoproteins. Cellular and humoral immunogenicity was confirmed in two mouse strains, including type I interferon receptor knockout mice, which are susceptible to CCHF disease. This vaccine protected all recipient animals from lethal disease in a challenge model adapted to represent infection via a tick bite. Histopathology and viral load analysis of protected animals confirmed that they had been exposed to challenge virus, even though they did not exhibit clinical signs. This is the first demonstration of efficacy of a CCHF vaccine.

Hazara virus infection is lethal for adult type I interferon receptor-knockout mice and may act as a surrogate for infection with the human-pathogenic Crimean-Congo hemorrhagic fever virus

Hazara virus (HAZV) is closely related to the Crimean-Congo hemorrhagic fever virus (CCHFV). HAZV has not been reported to cause human disease; work with infectious material can be carried out at containment level (CL)-2. By contrast, CCHFV causes a haemorrhagic fever in humans and requires CL-4 facilities. A disease model of HAZV infection in mice deficient in the type I interferon receptor is reported in this study. Dose-response effects were seen with higher doses, resulting in a shorter time to death and earlier detection of viral loads in organs. The lowest dose of 10 p.f.u. was still lethal in over 50 % of the mice. Histopathological findings were identified in the liver, spleen and lymph nodes, with changes similar to a recent mouse model of CCHFV infection. The findings demonstrate that inoculation of mice with HAZV may act as a useful surrogate model for the testing of antiviral agents against CCHFV.

Some functions of being fair and just--or not, in clinical psychoanalysis

The author suggests that the concepts of fairness and justice might be psychoanalytically useful. They are social ideas but often arise clinically. Since psychoanalysis is about intimate and internal events, the wide social and legal settings associated with formal justice are not addressed. Fairness and informal justice arise more intimately and are central here. Fairness is concerned with thorough consideration of an issue. To be fair, the people involved must be considered with impartiality before a decision. Justice generally is more formal, aiming to ensure the integrity of a system, its parts and individual members. It is noted that psychopathogenic conditions can arise in conflicting situations involving fairness and justice. Clinical illustrations suggest that the psychoanalytic process can implicitly aim to resolve their after-effects. Technique is addressed in this light. A central suggestion emerges here. The philosopher Jürgen Habermas proposes that justice rests essentially upon opportunity for argumentation between all those affected. The author suggests that psychoanalytic therapy is likewise a constructive argumentation.

Functional domains of the SYT and SYT-SSX synovial sarcoma translocation proteins and co-localization with the SNF protein BRM in the nucleus

The t(X;18)(p11.2;q11.2) chromosomal translocation commonly found in synovial sarcomas fuses the SYT gene on chromosome 18 to either of two similar genes, SSX1 or SSX2, on the X chromosome. The SYT protein appears to act as a transcriptional co-activator and the SSX proteins as co-repressors. Here we have investigated the functional domains of the proteins. The SYT protein has a novel conserved 54 amino acid domain at the N-terminus of the protein (the SNH domain) which is found in proteins from a wide variety of species, and a C-terminal domain, rich in glutamine, proline, glycine and tyrosine (the QPGY domain), which contains the transcriptional activator sequences. Deletion of the SNH domain results in a more active transcriptional activator, suggesting that this domain acts as an inhibitor of the activation domain. The C-terminal SSX domain present in SYT-SSX translocation protein contributes a transcriptional repressor domain to the protein. Thus, the fusion protein has transcriptional activating and repressing domains. We demonstrate that the human homologue of the SNF2/Brahama protein BRM co-localizes with SYT and SYT-SSX in nuclear speckles, and also interacts with SYT and SYT-SSX proteins in vitro. This interaction may provide an explanation of how the SYT protein activates gene transcription.

Etiology and outcome of acute pelvic inflammatory disease

We studied 71 women with the clinical diagnosis of acute pelvic inflammatory disease (PID) by laparoscopy and comprehensive microbiology in order to define the major etiologic determinants of poor fertility prognosis after tubal infection. Fifty women were found to have acute PID. Of the 50 women, 23 were pregnancy seeking and had a subsequent evaluation to determine fertility outcome. Seven of 13 women with non-gonococcal infection had an adverse reproductive outcome, compared with none of 10 women with gonococcal infection (P = .007). Two groups of causes for adverse reproductive outcome were found. Of the seven infertile women, four had initial tubal abscess, and three had evidence of Chlamydia trachomatis infection. This study directly documents the poor fertility prognosis for women with tubal abscess and suggests that women with culture and/or serological evidence of chlamydial infection also have a poor fertility prognosis.

Comparison of norfloxacin with cotrimoxazole for infection prophylaxis in acute leukemia. The trade-off for reduced gram-negative sepsis

A total of 63 neutropenic patients receiving cytotoxic therapy for acute leukemia were randomly allocated to receive norfloxacin (400 mg every 12 hours) or cotrimoxazole (160/800 mg every 12 hours) to prevent bacterial infection. Compliance was more than 95 percent and no adverse effects attributable to the study drugs were observed. The overall incidence of febrile illness (67 percent) was similar between the groups; however, no gram-negative bacillary infections were observed in 31 norfloxacin recipients compared with four of 32 cotrimoxazole recipients. Furthermore, nine norfloxacin recipients had 17 gram-positive bacteremias compared with two in two cotrimoxazole recipients (p = 0.0034). Norfloxacin was more effective than cotrimoxazole for preventing acquisition of aerobic gram-negative bacilli in surveillance cultures. Neither study drug allocation nor the presence of an indwelling central venous catheter influenced outcome among the 42 patients who subsequently received empiric systemic antibiotics for suspected infection. Although gram-positive infection remains an unsolved problem, norfloxacin appears to be a safe, effective, well-tolerated alternative to cotrimoxazole for preventing gram-negative infection in neutropenic patients with acute leukemia.

Selective gut decontamination with nalidixic acid or trimethoprim-sulfamethoxazole for infection prophylaxis in neutropenic cancer patients: relationship of efficacy to antimicrobial spectrum and timing of administration

Eighty-four cancer patients at risk of infection because of neutropenia were randomized to receive nalidixic acid as an alternative to trimethoprim-sulfamethoxazole (TMP-SMX) for infection prophylaxis. Infections were documented significantly earlier and more often among patients who entered the trial with neutrophil counts of less than 0.1 X 10(9)/liter. TMP-SMX recipients experienced fewer microbiologically documented infections and bacteremias and were free of infection for a higher proportion of days with severe neutropenia (less than 0.1 X 10(9)/liter) than nalidixic acid recipients. Gram-negative bacillary and Staphylococcus aureus infections accounted for the major differences. Although the majority of aerobic gram-negative bacilli were eliminated from the feces after 1 week of prophylaxis with either agent, TMP-SMX was proved superior to nalidixic acid in this regard and was associated with acquired drug resistance by gram-negative bacilli less frequently. Both agents selected for colonization and subsequent infection by gram-positive cocci. Our data suggest that prophylaxis is most likely to be effective if administered to patients for at least 1 week before they become severely neutropenic. Nalidixic acid used as a single agent in doses of 4 g daily, however, cannot be recommended as an alternative to TMP-SMX for infection prophylaxis in neutropenic cancer patients.

Preservation of colonization resistance parameters during empiric therapy with aztreonam in the febrile neutropenic patient

The role of the anaerobic intestinal flora in maintaining colonization resistance was examined in a study of empiric therapy in febrile neutropenic patients who received aztreonam plus tobramycin, aztreonam plus cloxacillin, or moxalactam plus tobramycin, regimens with differential effects on the anaerobic intestinal flora. Surveillance cultures showed that all regimens eradicated fecal carriage of enteric gram-negative bacilli but that fecal acquisition of fungi occurred in 4 (27%) of 15 aztreonam/tobramycin, 6 (43%) of 14 aztreonam/cloxacillin, and 13 (81%) of 16 moxalactam/tobramycin recipients. Fungi were acquired at 11 (22%) of 49 sites in aztreonam/tobramycin, 15 (31%) of 48 sites in aztreonam/cloxacillin, and 28 (54%) of 52 sites in moxalactam/tobramycin recipients. Aztreonam/tobramycin reduced fecal anaerobe counts by less than 1 log10; aztreonam/cloxacillin, by a mean of 2.5 log10; and moxalactam/tobramycin, by 5.1 log10 colony-forming units (cfu)/g of feces by day 10 +/- 3 of therapy. Elimination of the anaerobes was reflected by a reduction in concentrations of short-chain fatty acids (SCFAs) in fecal supernatants. Fecal specimens containing greater than or equal to 10(6) cfu of Bacteroides fragilis group organisms/g (dry weight) contained significantly higher concentrations of succinic, propionic, and isobutyric acids. Flat SCFA chromatograms were observed in 90% of fecal samples from which no anaerobes were recovered. Preservation of the anaerobic flora appears critical in the prevention of fungal acquisition in neutropenic patients.