Constitutive and conditional epitope-tagging of endogenous G protein coupled receptors in Drosophila.

To visualize the cellular and subcellular localization of neuromodulatory G-protein coupled receptors (GPCRs) in Drosophila, we implement a molecular strategy recently used to add epitope tags to ionotropic receptors at their endogenous loci. Leveraging evolutionary conservation to identify sites more likely to permit insertion of a tag, we generated constitutive and conditional tagged alleles for Drosophila 5-HT1A, 5-HT2A, 5-HT2B, Octß1R, Octß2R, two isoforms of OAMB, and mGluR. The conditional alleles allow for the restricted expression of tagged receptor in specific cell types, an option not available for any previous reagents to label these proteins. We show expression patterns for these receptors in female brains, and that 5-HT1A and 5-HT2B localize to the mushroom bodies and central complex respectively, as predicted by their roles in sleep. By contrast, the unexpected enrichment of Octß1R in the central complex and of 5-HT1A and 5-HT2A to nerve terminals in lobular columnar cells in the visual system suggest new hypotheses about their functions at these sites. Using an additional tagged allele of the serotonin transporter, a marker of serotonergic tracts, we demonstrate diverse spatial relationships between postsynaptic 5-HT receptors and presynaptic 5-HT neurons, consistent with the importance of both synaptic and volume transmission. Finally, we use the conditional allele of 5-HT1A to show that it localizes to distinct sites within the mushroom bodies as both a postsynaptic receptor in Kenyon cells and a presynaptic autoreceptor.Significance Statement In Drosophila, despite remarkable advances in both connectomic and genomic studies, antibodies to many aminergic GPCRs are not available. We have overcome this obstacle using evolutionary conservation to identify loci in GPCRs amenable to epitope-tagging, and CRISPR/Cas9 genome editing to generate eight novel lines. This method may also be applied to other GPCRs and allows cell-specific expression of the tagged receptor. We have used the tagged alleles we generated to address several questions that remain poorly understood. These include the relationship between pre- and postsynaptic sites that express the same receptor, and the use of relatively distant targets by presynaptic release sites that may employ volume transmission as well as standard synaptic signaling.

Systemic Involvement in Immunoglobulin G4-Related Ophthalmic Disease.

BACKGROUND: Immunoglobulin G4-related ophthalmic disease (IgG4-ROD) poses clinical challenges due to its heterogeneous ocular and systemic manifestations. We aim to report the systemic involvement and the clinical, serological and radiological associations of a cohort of Chinese patients. METHODS: A territory-wide, biopsy-proven, Chinese cohort. A retrospective, masked chart review of medical records, orbital images, and histopathology reports. RESULTS: A total of 122 (65 male) patients with a follow-up of 81 ± 49 (24 to 84) months were reviewed. Ninety (74%) patients presented bilaterally. Subacute upper eyelid swelling was the commonest presentation (82/122, 67%). During follow-up, 91/122 patients (75%) underwent extra-orbital imaging including computer tomography (692 films), ultrasonography (182 films), magnetic resonance imaging (76 films) and whole body FDG-PET scan (33 films). Eighty-six (95%) of these 91 patients had extra-orbital involvement radiologically (2.7 ± 1.6 regions, range: 0 to 9). Lymph node was the most prevalent (N = 60,66%), followed by salivary gland (N = 51,56%), lung (N = 49,54%), kidney (N = 22, 24%), hepatobiliary tree (N = 18, 20%) and pancreas (N = 17, 19%). Other organs include thyroid, aorta, meninges/brain and skin. Twenty-eight (23%) patients had allergic diseases (19 asthma, 16 allergic rhinitis, and 6 eczemas). Fifty-seven (48%) patients had paranasal sinusitis. Serum eosinophilia was associated with a higher number (3.24 versus 2.52, P = 0.0304) of organ involvement. Patients with deep organ involvement was associated with a higher age of IgG4-ROD onset (70 ± 12 versus 56 ± 13, P < 0.0001). CONCLUSIONS: 95% of the patients who underwent systemic imaging in our cohort had systemic organ involvement. An early physicians' assessment and radiological imaging are recommended after the diagnosis of IgG4-ROD.

Bats-The Magnificent Virus Player: SARS, MERS, COVID-19 and Beyond.

Irrespective of whether COVID-19 originated from a natural or a genetically engineered virus, the ultimate source of Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) is bats [...].

Cost-effectiveness of virtual reality and wet laboratory cataract surgery simulation.

PURPOSE: To evaluate the cost-effectiveness of phacoemulsification simulation training in virtual reality simulator and wet laboratory on operating theater performance. METHODS: Residents were randomized to a combination of virtual reality and wet laboratory phacoemulsification or wet laboratory phacoemulsification. A reference control group consisted of trainees who had wet laboratory training without phacoemulsification. All trainees were assessed on operating theater performance in 3 sequential cataract patients. International Council of Ophthalmology Surgical Competency Assessment Rubric-phacoemulsification (ICO OSCAR phaco) scores by 2 masked independent graders and cost data were used to determine the incremental cost-effectiveness ratio (ICER). A decision model was constructed to indicate the most cost-effective simulation training strategy based on the willingness to pay (WTP) per ICO OSCAR phaco score gained. RESULTS: Twenty-two trainees who performed phacoemulsification in 66 patients were analyzed. Trainees who had additional virtual reality simulation achieved higher mean ICO OSCAR phaco scores compared with trainees who had wet laboratory phacoemulsification and control (49.5 ± standard deviation [SD] 9.8 vs 39.0 ± 15.8 vs 32.5 ± 12.1, P < .001). Compared with the control group, ICER per ICO OSCAR phaco of wet laboratory phacoemulsification was $13,473 for capital cost and $2209 for recurring cost. Compared with wet laboratory phacoemulsification, ICER per ICO OSCAR phaco of additional virtual reality simulator training was US $23,778 for capital cost and $1879 for recurring cost. The threshold WTP values per ICO OSCAR phaco score for combined virtual reality simulator and wet laboratory phacoemulsification to be most cost-effective was $22,500 for capital cost and $1850 for recurring cost. CONCLUSIONS: Combining virtual reality simulator with wet laboratory phacoemulsification training is effective for skills transfer in the operating theater. Despite of the high capital cost of virtual reality simulator, its relatively low recurring cost is more favorable toward cost-effectiveness.

Ocular Surface Evaluation in Immunoglobulin G4-Related Ophthalmic Disease.

PURPOSE: To evaluate the functional and structural changes of the meibomian glands and ocular surface in immunoglobulin G4-related ophthalmic disease (IgG4-ROD) patients. DESIGN: Cross-sectional, matched case-control comparison study. METHODS: This study included 64 patients with biopsy-proven IgG4-ROD (aged 63.4 ± 12.2 years, 39 male) and 64 sex- and age-matched healthy controls. Patients were managed by hospitals covering the publicly funded ophthalmology service in Hong Kong. Outcome measures included anterior segment examination and keratographic and meibographic imagings. RESULTS: A total of 64 worst-affected eyes of the 64 IgG4-ROD patients were analyzed. Corneal fluorescein staining (P = .0187), lid margin telangiectasia (P = .0360), lid-parallel conjunctival folds (P = .0112), papillae (P = .0393), meibomian gland plugging (P = .0001), meibomian gland expressibility (P = .0001), and meibum quality (P = .0001) were more significant in IgG4-ROD patients compared with healthy controls. Both upper and lower meibomian gland dropouts (P = .001 and .0003), and tear meniscus height (P = .0001) were higher in IgG4-ROD patients. Non-invasive tear break-up time (NITBUT) (P = .0166) and Schirmer test results (P = .0243) were lower in IgG4-ROD patients. Upper (r = 0.336, P = .0140) meibomian gland dropouts and NITBUT (r = -0.293, P = .0497) were positively and negatively correlated with the IgG4-ROD onset age, respectively. The number of extraocular organ involvement was negatively correlated with the Schirmer test(r = -0.341, P = .0167). Lower NITBUT was found in IgG4-ROD eyes with lacrimal gland enlargement than in IgG4-ROD eyes without lacrimal gland enlargement radiologically (P < .0001). CONCLUSIONS: IgG4-ROD patients showed features of both aqueous tear deficiency and evaporative dry eye disease. We recommend ocular surface evaluation to all patients newly diagnosed with IgG4-ROD. Further studies are warranted to clarify the mechanism of IgG4-related dry eye disease.

A prospective study on neonatal ophthalmic injuries associated with forceps delivery.

BACKGROUND: Assisted delivery by forceps is needed to expedite vaginal delivery in certain maternal and fetal conditions. The aim of this study was to evaluate the incidence and the extent of ophthalmological injuries in neonates after forceps delivery. METHODS: Women with cephalic fetuses delivered vaginally by forceps from July 2020 to June 2022 were recruited prospectively. Ophthalmologists would be consulted when there were signs of external ophthalmic injuries, such as periorbital forceps marks or facial bruising. Demographic data, pregnancy characteristics, delivery details, and perinatal outcomes were evaluated to identify any associated risk factors for neonatal ophthalmological injuries. RESULTS: A total of 77 forceps deliveries were performed in the study period, in which 20 cases (26%) required ophthalmological consultations. There were more right or left occipital fetal head positions in the group requiring ophthalmological assessment than those that did not require assessment (35% vs 12.3% [P = 0.023]). The degree of moulding of the fetal head was more marked in the former group (65% vs 28% [P = 0.001]). The overall incidence of detectable ophthalmological lesions was 16.9% (13/77). All ophthalmic injuries were mild, and most resolved with conservative management. CONCLUSIONS: In our study cohort, external ophthalmic injuries were common after forceps delivery. We recommended ophthalmological consultation in newborns delivered by forceps with evidence of compressive trauma to rule out serious ophthalmological trauma.

Removal of Intraocular Foreign Bodies Using a Modified Flute Needle.

PURPOSE: To describe the construction of a novel intraocular snare and evaluate its effectiveness in intraocular foreign body (IOFB) removal. METHOD: This is a retrospective consecutive case series. Five patients underwent pars plana vitrectomy and IOFB removal using the intraocular snare constructed from modified flute needle. RESULTS: All IOFBs were successfully engaged and removed with the snare on the first attempt. Three of the 5 cases (60%) enjoyed good visual outcome (0.4-1.0) postoperatively. No complication related to the use of the snare was encountered in this case series. CONCLUSION: Intraocular foreign body snare is simple, safe, and effective in IOFB removal.

Combining Transoral Nasopharyngeal Brush and Plasma Epstein-Barr Virus DNA in Detecting Locally Recurrent Nasopharyngeal Carcinoma.

OBJECTIVE: To evaluate the sensitivities and specificities of Epstein-Barr virus (EBV) DNA in the detection of locally recurrent or persistent nasopharyngeal carcinoma (NPC) through nasopharyngeal (NP) brush biopsy and plasma, respectively, and whether a combination of both would be superior to the individual tests. STUDY DESIGN: A case-control study was conducted from September 2016 to June 2022. SETTING: A multicentre study at 3 tertiary referral centers in Hong Kong was conducted by the Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong. METHODS: Twenty-seven patients with biopsy-confirmed locally recurrent NPC were recruited as study subjects. Magnetic resonance imaging was performed to rule out regional recurrence. The control group consisted of 58 patients with a prior history of NPC who were now disease-free based on endoscopic and imaging findings. Patients underwent both the transoral NP brush (NP Screen®) and blood for plasma Epstein-Barr DNA levels. RESULTS: The sensitivity and specificity of the combined modalities were 84.62% and 85.19%, respectively. The positive predictive value was 73.33% and the negative predictive value was 92.0%. CONCLUSION: The combination of NP brush biopsy and plasma EBV DNA is potentially an additional surveillance modality in detecting the local recurrence of NPC. Further study with a larger sample size would be required to validate the cutoff values.

An autocrine signaling circuit in hepatic stellate cells underlies advanced fibrosis in nonalcoholic steatohepatitis.

Advanced hepatic fibrosis, driven by the activation of hepatic stellate cells (HSCs), affects millions worldwide and is the strongest predictor of mortality in nonalcoholic steatohepatitis (NASH); however, there are no approved antifibrotic therapies. To identify antifibrotic drug targets, we integrated progressive transcriptomic and morphological responses that accompany HSC activation in advanced disease using single-nucleus RNA sequencing and tissue clearing in a robust murine NASH model. In advanced fibrosis, we found that an autocrine HSC signaling circuit emerged that was composed of 68 receptor-ligand interactions conserved between murine and human NASH. These predicted interactions were supported by the parallel appearance of markedly increased direct stellate cell-cell contacts in murine NASH. As proof of principle, pharmacological inhibition of one such autocrine interaction, neurotrophic receptor tyrosine kinase 3-neurotrophin 3, inhibited human HSC activation in culture and reversed advanced murine NASH fibrosis. In summary, we uncovered a repertoire of antifibrotic drug targets underlying advanced fibrosis in vivo. The findings suggest a therapeutic paradigm in which stage-specific therapies could yield enhanced antifibrotic efficacy in patients with advanced hepatic fibrosis.

Are we facing an increasing surgical demand for high myopic traction maculopathies? A 12-year study from Hong Kong.

PURPOSE: We aimed to investigate the longitudinal change in the number of surgically operated myopic traction maculopathies (MTM) cases at a tertiary eye centre. METHODS: A retrospective study of all consecutive cases of surgically operated MTM over 12 years (2009-2020) was conducted in a myopia prevalent region. We compared outcomes among three groups: (1) myopic macular hole (MH), (2) myopic macular hole with retinal detachment (MHRD), and (3) myopic foveoschisis with retinal detachment (MFRD). RESULTS: Fifty-one cases were included in the study (8 cases of MH, 33 cases of MHRD and 10 cases of MFRD). The overall mean age was 63.8 +/- 8.7 with a female preponderance (2:1). The mean age of the MH group (58.6) was significantly younger than the MHRD group (64.2) and MFRD group (66.6) (p = 0.02). Subgroup analysis using ATN classification did not show its correlation with both visual improvement and anatomical success. When comparing the first 6-year period (2009-2014) with the second 6-year period (2015-2020), there was a significant increase in the number of cases (p = 0.01). CONCLUSION: We observe an increase in the number of surgically operated MTM. This follows the trend of the global rise in the prevalence of myopia and baby boomers entering retirement.

Malignancies in Immunoglobulin G4-related ophthalmic disease.

PURPOSE: Clinical phenotypes in Immunoglobulin G4-related disease (IgG4-RD) according to the patterns of affecting organs have different risks of malignancies. We attempt to determine the association of malignancies with IgG4-related ophthalmic disease (IgG4-ROD). DESIGN: Retrospective cohort study. METHODS: Review of medical records, orbital images and histopathology reports in a territory-wide cohort of biopsy proven IgG4-ROD patients from 2005-2019. FINDINGS: Among 122 patients who had biopsies taken from adnexal lesions including lacrimal glands (n = 108), orbital mass (n = 30), infiltrated orbital fat (n = 10), conjunctiva (n = 2) or extraocular muscles (n = 3), 13% (16/122) developed malignancies over 73 ± 48months' follow-up. There were 9 cases of ocular adnexal lymphoma (OAL) and 7 extra-orbital malignancies. Compared with the general population, the incidence of OAL was significantly higher (standardized incidence ratios, SIRs = 10.0, 95%CI = 4.5-17.6) while that of extra-orbital malignancies was similar. The SIRs was highest within the first year (SIR = 46.7, 95%CI = 18.5-87.6) when 7 OAL were concomitantly diagnosed. Patients who developed OAL or extra-orbital malignancies were older than other patients at IgG4-ROD diagnosis (64.9 ± 7.1, 68.3 ± 8.5 versus 55.2 ± 15.0 years, P < 0.05). Asymmetric lacrimal gland enlargement (78% versus 13%), lack of frontal (0% versus 12%) or infraorbital nerve enlargement (0% versus 36%) were associated with OAL (all P < 0.05). Pre-treatment serum IgG4 level or extra-orbital IgG4-RD involvement was similar among patients with or without malignancies. CONCLUSION: In this biopsy-proven IgG4-ROD cohort, 7% developed OAL which was 10 times higher than the general population. Patients with asymmetric lacrimal gland enlargement or without trigeminal nerves involvement radiologically were associated with OAL.

Treatment outcomes and their determinants of IgG4-related ophthalmic disease: a territory-wide cohort study.

BACKGROUND: Oral corticosteroid remains the first-line treatment of IgG4-related ophthalmic disease, but steroid-dependence is common and serious. Factors associated with steroid dependence and relapse have to be further explored. STUDY POPULATION: A city-wide, biopsy-proven, Chinese cohort. METHODS: Retrospective, masked review of medical records, orbital images and histopathology reports. RESULTS: There were 101 patients with at least 24-month follow-up. Up to 82% (82/101) received oral corticosteroid as first-line treatments, and 7 of them received also concomitant steroid-sparing agents (SSA)/biological agents as primary treatment. There was 61% (50/82) of patients required long-term corticosteroid (alone=23, with SSA=27) after 1.9±0.7 (range 1-5) relapses. When compared with the 21% (17/82) of patients who tapered corticosteroid successfully for 24 months, steroid dependence was associated with elevated baseline serum IgG4 level (94% vs 65%, p<0.01) and Mikulicz syndrome (46% vs 18%, p<0.05). Up to 13% (11/82) of patients tolerated residual disease after tapering off corticosteroid. There was 17% (17/101) of patients did not require any medications after biopsies. They were more likely to have debulking surgeries (71% vs 40%, p<0.05), discrete orbital lesions (65% vs 26%, p<0.05), normal baseline serum IgG4 level (24% vs 6%, p<0.05) and no Mikulicz syndrome (94% vs 61%, p<0.05). CONCLUSION: In this cohort, 60% of patients required long-term maintenance oral corticosteroid. Elevated pretreatment serum IgG4 level and Mikulicz syndrome were associated with steroid dependence. Debulking surgery is an alternative for a subgroup of patients with discrete orbital lesions, normal baseline IgG4 level and no Mikulicz syndrome.

Constitutive and conditional epitope-tagging of endogenous G protein coupled receptors in Drosophila.

To visualize the cellular and subcellular localization of neuromodulatory G-protein coupled receptors (GPCRs) in Drosophila , we implement a molecular strategy recently used to add epitope tags to ionotropic receptors at their endogenous loci. Leveraging evolutionary conservation to identify sites more likely to permit insertion of a tag, we generated constitutive and conditional tagged alleles for Drosophila 5-HT1A, 5-HT2A, 5-HT2B, Octß1R, Octß2R, two isoforms of OAMB, and mGluR. The conditional alleles allow for the restricted expression of tagged receptor in specific cell types, an option not available for any previous reagents to label these proteins. We show that 5-HT1A and 5-HT2B localize to the mushroom bodies and central complex respectively, as predicted by their roles in sleep. By contrast, the unexpected enrichment of Octß1R in the central complex and of 5-HT1A and 5-HT2A to nerve terminals in lobular columnar cells in the visual system suggest new hypotheses about their function at these sites. Using an additional tagged allele of the serotonin transporter, a marker of serotonergic tracts, we demonstrate diverse spatial relationships between postsynaptic 5-HT receptors and presynaptic 5-HT neurons, consistent with the importance of both synaptic and volume transmission. Finally, we use the conditional allele of 5-HT1A to show that it localizes to distinct sites within the mushroom bodies as both a postsynaptic receptor in Kenyon cells and a presynaptic autoreceptor. Significance Statement: In Drosophila , despite remarkable advances in both connectomic and genomic studies, antibodies to many aminergic GPCRs are not available. We have overcome this obstacle using evolutionary conservation to identify loci in GPCRs amenable to epitope-tagging, and CRISPR/Cas9 genome editing to generated eight novel lines. This method also may be applied to other GPCRs and allows cell-specific expression of the tagged locus. We have used the tagged alleles we generated to address several questions that remain poorly understood. These include the relationship between pre- and post-synaptic sites that express the same receptor, and the use of relatively distant targets by pre-synaptic release sites that may employ volume transmission as well as standard synaptic signaling.

Fixed Quarterly Dosing of Aflibercept after Loading Doses in Neovascular Age-Related Macular Degeneration in Chinese Eyes.

We aimed to investigate the success rate of planned fixed quarterly aflibercept injections after three loading doses (QDA3L) to achieve stability without recurrence in neovascular age-related macular degeneration (nAMD) at a tertiary eye centre. A retrospective study was conducted over five years (2017-2021) by including all consecutive cases of nAMD treated with three initial aflibercept injections four weeks apart, followed by planned injection appointments every 12 to 16 weeks starting from week 20. The primary endpoint was to determine the proportion of patients who maintained disease inactivity at week 52 and week 104. A total of 40 eyes of 40 patients were included. The overall mean age was 80.8, with a male preponderance. The overall success rate in our study population was 52.9% and 53.6% at week 52 and week 104, respectively. The fovea remained dry at 85.3% at week 52 and 82.1% at week 104, and 85.3% and 85.7% of subjects lost fewer than 15 ETDRS letters at week 52 and week 104, respectively. While this study does not suggest the superiority of this regimen, the success and failure rates obtained in our study can be used in the counselling process for this particular fixed treatment regimen for nAMD.

Psychological Impact of Cancellation of Elective Surgeries for Ophthalmic Patients during COVID-19 Pandemic.

The COVID-19 pandemic has disrupted routine hospital services globally. The cancellation of elective surgeries placed a psychological burden on patients. A questionnaire study was conducted to identify the psychological impact of canceling cataract operations on patients at Kowloon East Cataract Center, Tseung Kwan O Hospital, Hong Kong, from April to June 2020. In total, 99 participants aged 59 years old and above, who had their cataract surgeries postponed or as scheduled, were studied using the standardized patient health questionnaire (PHQ-9) and generalized anxiety disorder questionnaire (GAD-7). None of the patients who had their cataract surgeries rescheduled reached the cutoff score for major depression in PHQ-9, whereas, according to GAD-7, five patients had mild symptoms of anxiety, and one had severe symptoms. There was no significant psychosocial impact of the cancellation of cataract surgeries on patients.

Radiological Determinants of Complicated Immunoglobulin G4-Related Ophthalmic Disease: A Territory-Wide Cohort Study.

PURPOSE: To evaluate the presenting radiological features of immunoglobulin G4-related ophthalmic disease (IgG4-ROD) and their associations with IgG4-related optic neuropathy (IgG4-RON), and IgG4-related ocular adnexal lymphoma (IgG4-ROL). METHODS: A territory-wide, biopsy-proven, Chinese cohort. Masked review of orbital images, medical records, and histopathology reports. RESULTS: A total of 115 (94%) of the 122 patients in our cohort had preoperative orbital images (computed tomography=105, magnetic resonance imaging=40). Among them, 103/115 (90%) showed enlarged lacrimal glands, and 91 (88%) were bilateral. Nerve enlargement was observed: infraorbital in 31/115 (27%) patients and frontal in 17/115 (15%), 10 and 9 being bilateral, respectively. At least 1 or more extraocular muscle (EOM) enlargement was found in 41/115 (37%) patients, bilaterally in 20. Lateral rectus occurred in 30 (73%) of these 41 EOM patients and inferior rectus in 28 (68%). Two adjacent EOMs (inferior and lateral recti in 11 patients, inferior and medial recti in 7 patients) or multiple EOMs (at least 3) were enlarged in 23/41 (56%) and 13/41 (32%) of the patients, respectively. Intraconal lesions (67% vs 11%, P<0.05), infraorbital (83% vs 23%, P<0.005), or frontal (50% vs 15%, P<0.05) nerve enlargement was significantly associated with IgG4-RON (6 patients) by univariate analyses. Asymmetric lacrimal gland enlargement and discrete orbital mass (both P<0.05) were associated with IgG4-ROL (9 patients) by multivariate analyses. CONCLUSIONS: In this IgG4-ROD cohort, most patients had bilateral enlarged lacrimal glands, and the lateral rectus is the most frequently involved EOM. For the first time, unique radiological patterns associated with the development of IgG4-RON and IgG4-ROL are found.

A platform technology for generating subunit vaccines against diverse viral pathogens.

The COVID-19 pandemic response has shown how vaccine platform technologies can be used to rapidly and effectively counteract a novel emerging infectious disease. The speed of development for mRNA and vector-based vaccines outpaced those of subunit vaccines, however, subunit vaccines can offer advantages in terms of safety and stability. Here we describe a subunit vaccine platform technology, the molecular clamp, in application to four viruses from divergent taxonomic families: Middle Eastern respiratory syndrome coronavirus (MERS-CoV), Ebola virus (EBOV), Lassa virus (LASV) and Nipah virus (NiV). The clamp streamlines subunit antigen production by both stabilising the immunologically important prefusion epitopes of trimeric viral fusion proteins while enabling purification without target-specific reagents by acting as an affinity tag. Conformations for each viral antigen were confirmed by monoclonal antibody binding, size exclusion chromatography and electron microscopy. Notably, all four antigens tested remained stable over four weeks of incubation at 40°C. Of the four vaccines tested, a neutralising immune response was stimulated by clamp stabilised MERS-CoV spike, EBOV glycoprotein and NiV fusion protein. Only the clamp stabilised LASV glycoprotein precursor failed to elicit virus neutralising antibodies. MERS-CoV and EBOV vaccine candidates were both tested in animal models and found to provide protection against viral challenge.