Equine neuroaxonal dystrophy/degenerative myeloencephalopathy in Gypsy Vanner horses

BACKGROUND

Equine neuroaxonal dystrophy/degenerative myeloencephalopathy (eNAD/EDM) is a neurodegenerative disease that primarily affects young, genetically predisposed horses that are deficient in vitamin E. Equine NAD/EDM has not previously been documented in Gypsy Vanner horses (GVs).

OBJECTIVES

To evaluate: (1) the clinical phenotype, blood vitamin E concentrations before and after supplementation and pedigree in a cohort of GV horses with a high prevalence of neurologic disease suspicious for eNAD/EDM and (2) to confirm eNAD/EDM in GVs through postmortem evaluation.

ANIMALS

Twenty-six GVs from 1 farm in California and 2 cases from the Midwestern U.S.

METHODS

Prospective observational study on Californian horses; all 26 GVs underwent neurologic examination. Pre-supplementation blood vitamin E concentration was assessed in 17- GVs. Twenty-three were supplemented orally with 10 IU/kg of liquid RRR-alpha-tocopherol once daily for 28 days. Vitamin E concentration was measured in 23 GVs after supplementation, of which 15 (65%) had pre-supplementation measurements. Two clinically affected GVs from California and the 2 Midwestern cases had necropsy confirmation of eNAD/EDM.

RESULTS

Pre-supplementation blood vitamin E concentration was ≤2.0 μg/mL in 16/17 (94%) of GVs from California. Post-supplementation concentration varied, with a median of 3.39 μg/mL (range, 1.23-13.87 μg/mL), but only 12/23 (52%) were normal (≥3.0 μg/mL). Normalization of vitamin E was significantly associated with increasing age (P = .02). Euthanized horses (n = 4) had eNAD/EDM confirmed at necropsy.

CONCLUSIONS AND CLINICAL IMPORTANCE

GVs could have a genetic predisposition to eNAD/EDM. Vitamin E supplementation should be considered and monitored in young GVs.

A polyvalent RNA vaccine reduces the immune imprinting phenotype in mice and induces neutralizing antibodies against omicron SARS-CoV-2

Immune imprinting is now evident in COVID-19 vaccinated people. This phenomenon may impair the development of effective neutralizing antibodies against variants of concern (VoCs), mainly Omicron and its subvariants. Consequently, the boost doses with bivalent vaccines have not shown a significant gain of function regarding the neutralization of Omicron. The approach to design COVID-19 vaccines must be revised to improve the effectiveness against VoCs. Here, we took advantage of the self-amplifying characteristic of RepRNA and developed a polyvalent formulation composed of mRNA from five VoCs. LION/RepRNA Polyvalent induced neutralizing antibodies in mice previously immunized with LION/RepRNA D614G and reduced the imprinted phenotype associated with low neutralization capacity of Omicron B.1.1.529 pseudoviruses. The polyvalent vaccine can be a strategy to handle the low neutralization of Omicron VoC, despite booster doses with either monovalent or bivalent vaccines.

CD4+ T Cell Responses to Toxoplasma gondii Are a Double-Edged Sword

CD4+ T cells have been found to play critical roles in the control of both acute and chronic Toxoplasma infection. Previous studies identified a protective role for the Toxoplasma CD4+ T cell-eliciting peptide AS15 (AVEIHRPVPGTAPPS) in C57BL/6J mice. Herein, we found that immunizing mice with AS15 combined with GLA-SE, a TLR-4 agonist in emulsion adjuvant, can be either helpful in protecting male and female mice at early stages against Type I and Type II Toxoplasma parasites or harmful (lethal with intestinal, hepatic, and spleen pathology associated with a storm of IL6). Introducing the universal CD4+ T cell epitope PADRE abrogates the harmful phenotype of AS15. Our findings demonstrate quantitative and qualitative features of an effective Toxoplasma-specific CD4+ T cell response that should be considered in testing next-generation vaccines against toxoplasmosis. Our results also are cautionary that individual vaccine constituents can cause severe harm depending on the company they keep.

Immunogenicity of a Plasmodium vivax vaccine based on the duffy binding protein formulated using adjuvants compatible for use in humans

The invasion of reticulocytes by Plasmodium vivax merozoites is dependent on the interaction of the Plasmodium vivax Duffy Binding Protein (PvDBP) with the Duffy antigen receptor for chemokines (DARC). The N-terminal cysteine-rich region II of PvDBP (PvDBPII), which binds DARC, is a leading P. vivax malaria vaccine candidate. Here, we have evaluated the immunogenicity of recombinant PvDBPII formulated with the adjuvants Matrix-M and GLA-SE in mice. Analysis of the antibody responses revealed comparable ELISA recognition titres as well as similar recognition of native PvDBP in P. vivax schizonts by immunofluorescence assay. Moreover, antibodies elicited by the two adjuvant formulations had similar functional properties such as avidity, isotype profile and inhibition of PvDBPII-DARC binding. Furthermore, the anti-PvDBPII antibodies were able to block the interaction of DARC with the homologous PvDBPII SalI allele as well as the heterologous PvDBPII PvW1 allele from a Thai clinical isolate that is used for controlled human malaria infections (CHMI). The cross-reactivity of these antibodies with PvW1 suggest that immunization with the PvDBPII SalI strain should neutralize reticulocyte invasion by the challenge P. vivax strain PvW1.

Cerebrospinal fluid and serum proteomic profiles accurately distinguish neuroaxonal dystrophy from cervical vertebral compressive myelopathy in horses

BACKGROUND

Cervical vertebral compressive myelopathy (CVCM) and equine neuroaxonal dystrophy/degenerative myeloencephalopathy (eNAD/EDM) are leading causes of spinal ataxia in horses. The conditions can be difficult to differentiate, and there is currently no diagnostic modality that offers a definitive antemortem diagnosis.

OBJECTIVE

Evaluate novel proteomic techniques and machine learning algorithms to predict biomarkers that can aid in the antemortem diagnosis of noninfectious spinal ataxia in horses.

ANIMALS

Banked serum and cerebrospinal fluid (CSF) samples from necropsy-confirmed adult eNAD/EDM (n = 47) and CVCM (n = 25) horses and neurologically normal adult horses (n = 45).

METHODS

. A subset of serum and CSF samples from eNAD/EDM (n = 5) and normal (n = 5) horses was used to evaluate the proximity extension assay (PEA). All samples were assayed by PEA for 368 neurologically relevant proteins. Data were analyzed using machine learning algorithms to define potential diagnostic biomarkers.

RESULTS

Of the 368 proteins, 84 were detected in CSF and 146 in serum. Eighteen of 84 proteins in CSF and 30/146 in serum were differentially abundant among the 3 groups, after correction for multiple testing. Modeling indicated that a 2-protein test using CSF had the highest accuracy for discriminating among all 3 groups. Cerebrospinal fluid R-spondin 1 (RSPO1) and neurofilament-light (NEFL), in parallel, predicted normal horses with an accuracy of 87.18%, CVCM with 84.62%, and eNAD/EDM with 73.5%.

MAIN LIMITATIONS

Cross-species platform. Uneven sample size.

CONCLUSIONS AND CLINICAL IMPORTANCE

Proximity extension assay technology allows for rapid screening of equine biologic matrices for potential protein biomarkers. Machine learning analysis allows for unbiased selection of highly accurate biomarkers from high-dimensional data.

Recombinant protein KR95 as an alternative for serological diagnosis of human visceral leishmaniasis in the Americas

In the Americas, visceral leishmaniasis (VL) is caused by the protozoan Leishmania infantum, leading to death if not promptly diagnosed and treated. In Brazil, the disease reaches all regions, and in 2020, 1,933 VL cases were reported with 9.5% lethality. Thus, an accurate diagnosis is essential to provide the appropriate treatment. Serological VL diagnosis is based mainly on immunochromatographic tests, but their performance may vary by location, and evaluation of diagnostic alternatives is necessary. In this study, we aimed to evaluate the performance of ELISA with the scantily studied recombinant antigens, K18 and KR95, comparing their performance with the already known rK28 and rK39. Sera from parasitologically confirmed symptomatic VL patients (n = 90) and healthy endemic controls (n = 90) were submitted to ELISA with rK18 and rKR95. Sensitivity (95% CI) was, respectively, 83.3% (74.2-89.7) and 95.6% (88.8-98.6), and specificity (95% CI) was 93.3% (85.9-97.2) and 97.8% (91.8-99.9). For validation of ELISA with the recombinant antigens, we included samples from 122 VL patients and 83 healthy controls collected in three regions in Brazil (Northeast, Southeast, and Midwest). When comparing the results obtained with the VL patients' samples, significantly lower sensitivity was obtained by rK18-ELISA (88.5%, 95% CI: 81.5-93.2) compared with rK28-ELISA (95.9%, 95% CI: 90.5-98.5), but the sensitivity was similar comparing rKR95-ELISA (95.1%, 95% CI: 89.5-98.0), rK28-ELISA (95.9%, 95% CI: 90.5-98.5), and rK39-ELISA (94.3%, 95% CI: 88.4-97.4). Analyzing the specificity, it was lowest with rK18-ELISA (62.7%, 95% CI: 51.9-72.3) with 83 healthy control samples. Conversely, higher and similar specificity was obtained by rKR95-ELISA (96.4%, 95% CI: 89.5-99.2), rK28-ELISA (95.2%, 95% CI: 87.9-98.5), and rK39-ELISA (95.2%, 95% CI: 87.9-98.5). There was no difference in sensitivity and specificity across localities. Cross-reactivity assessment, performed with sera of patients diagnosed with inflammatory disorders and other infectious diseases, was 34.2% with rK18-ELISA and 3.1% with rKR95-ELISA. Based on these data, we suggest using recombinant antigen KR95 in serological assays for VL diagnosis.

Health system recovery from Covid-19: What policies are health systems using to tackle backlogs and bring down waiting times in the wake of the pandemic?

The pandemic has left even the most well-equipped health systems vulnerable and required difficult trade-offs to balance both Covid-19 and non-Covid-19 health services. Across the globe, planned and routine health services have been scaled down during peaks of the crisis to meet the needs of acute and Covid-19-related care, resulting in growing care backlogs and increase in the number of patients waiting for treatment. To identify potential policy solutions, we have consulted the Covid-19 Health System Response Monitor, interviewed experts and analysed recovery strategies in 16 OECD and EU countries. Many country responses display striking similarities despite very real differences in the organisation of health and care services. These include:

1) increasing the supply of workforce by widening the scope of authority for different roles, investing heavily in recruitment and training for key roles, and improving the terms and conditions of work;

2) boosting productivity by introducing financial incentives and targets, reconfiguring facilities to better separate planned and emergency work”, optimising referrals and waiting list management, and outsourcing more care to the private sector; and

3) investing in out-of-hospital alternatives to care, including expanding primary and community care models and developing digital, home care and rehabilitative capacity

Policymakers will need to balance the immediate pressures of clearing backlogs with long-term measures that place services on a more sustainable footing. International experience shows how these can be at odds, especially if actions taken in the short term exhaust an already depleted workforce, or resolve Covid-19-specific problems but leave services less prepared for tomorrow's challenges.

Meeting the governance challenges of integrated health and social care

Background

Many countries are experimenting with novel ways of organising and delivering more integrated health and social care. Governance is relatively neglected as a focus of attention in this context but addressing governance challenges is key for successful collaboration.

Methods

Cross-country case analysis involving document review and semi-structured interviews with 27 local, regional and national level stakeholders in Italy, the Netherlands and Scotland. We used the Transparency, Accountability, Participation, Integrity and Capability (TAPIC) framework to structure our analytical enquiry to explore factors that influence the governance arrangements in each system.

Results

Governance arrangements ranged from informal agreements in the Netherlands to mandated integration in Scotland. Novel service models were generally participative involving a wide range of stakeholders, including the public, although integration was seen to be driven, largely, from a health perspective. In Italy and Scotland some reversion to ‘command & control’ was reported in response to the imperatives of the Covid-19 pandemic. Policies, budgets, auditing and reporting systems that are clearly aligned at all levels were seen to help with implementing innovations in service organisation. Where alignment was lacking, cooperation and integration was suboptimal, regardless of whether governance arrangements were statutory or not. There was wide recognition of the importance of buy-in. Enablers of greater engagement included visible leadership, time and long-standing working relationships. Lack of suitable indicators and openness to data sharing to measure integration hindered working relationships and thus the successful delivery of integrated services.

Conclusions

Our study provides important insights into how to more effectively and efficiently govern service delivery structures within care systems. We will discuss approaches to governance that help support more resilient integrated care systems.

Key messages

• Different governance arrangements face common challenges to greater integration of care. Enablers include strong leadership, inclusivity and openness to work across traditional boundaries.

• Meeting the governance challenges of integrated health and social care requires clear lines of accountability, aligned policies, budgets and reporting systems.

A cross-country comparison on providing health services effectively during the first wave of COVID-19

At the onset of the COVID-19 pandemic, health care providers had to abruptly change their way of providing care in order to simultaneously plan for and manage a rise of COVID-19 cases while maintaining essential health services. Even the most well-resourced health systems faced pressures from new challenges brought on by COVID-19, and every country had to make difficult choices about how to maintain access to essential care while treating a novel communicable disease. Using the information available on the HSRM platform from the early phases of the pandemic, we analyze how countries planned services for potential surge capacity, designed patient flows ensuring separation between COVID-19 and non-COVID-19 patients, and maintained routine services in both hospital and outpatient settings. Many country responses displayed striking similarities despite very real differences in the organization of health and care services. These include transitioning the management of COVID-19 mild cases from hospitals to outpatient settings, increasing the use of remote consultations, and cancelling or postponing non-urgent services during the height of the first wave. In the immediate future, countries will have to continue balancing care for COVID-19 and non-COVID-19 patients to minimize adverse health outcomes, ideally with supporting guidelines and COVID-19-specific care zones. Many countries expect to operate at lower capacity for routinely provided care, which will impact patient access and waiting times. Looking forward, policymakers will have to consider whether strategies adopted during the COVID-19 pandemic will become permanent features of care provision.

Benign adenoidal hypertrophy caused by adenovirus presenting as a nasopharyngeal mass concerning for malignancy

Benign adenoidal hypertrophy is the most common cause of nasopharyngeal obstruction. However, depending on size and location, masses may cause nasopharyngeal obstruction. We present our experiences with a ten-year-old female who presented with what appeared to be a large nasopharyngeal mass that was initially favored to be malignant and was ultimately found to be adenoid hypertrophy related to acute infection with adenovirus.

Engineering and characterization of a novel Self Assembling Protein for Toxoplasma peptide vaccine in HLA-A*11:01, HLA-A*02:01 and HLA-B*07:02 transgenic mice

Fighting smart diseases requires smart vaccines. Novel ways to present protective immunogenic peptide epitopes to human immune systems are needed. Herein, we focus on Self Assembling Protein Nanoparticles (SAPNs) as scaffolds/platforms for vaccine delivery that produce strong immune responses against Toxoplasma gondii in HLA supermotif, transgenic mice. Herein, we present a useful platform to present peptides that elicit CD4+, CD8+ T and B cell immune responses in a core architecture, formed by flagellin, administered in combination with TLR4 ligand-emulsion (GLA-SE) adjuvant. We demonstrate protection of HLA-A*11:01, HLA-A*02:01, and HLA-B*07:02 mice against toxoplasmosis by (i) this novel chimeric polypeptide, containing epitopes that elicit CD8+ T cells, CD4+ T helper cells, and IgG2b antibodies, and (ii) adjuvant activation of innate immune TLR4 and TLR5 pathways. HLA-A*11:01, HLA-A*02:01, and HLA-B*07:02q11 transgenic mouse splenocytes with peptides demonstrated predicted genetic restrictions. This creates a new paradigm-shifting vaccine approach to prevent toxoplasmosis, extendable to other diseases.

Acute and chronic effects of multivitamin/mineral supplementation on objective and subjective energy measures

Background

Vitamins and minerals play an essential role within many cellular processes including energy production and metabolism. Previously, supplementation with a multivitamin/mineral (MVM) for ≥28 days resulted in improvements to cognition and subjective state. We have also demonstrated shifts in metabolism during cognitively demanding tasks following MVM in females, both acutely and following 8-week supplementation. The current study aimed to assess these effects further in males and females using metabolically challenging exercise and cognitive tasks.

Methods

The current randomised, placebo-controlled, parallel groups study investigated the effects of a MVM complex in 82 healthy young (18-35y) exercisers. Subjective ratings and substrate metabolism were assessed during 30 min each of increasingly effortful incremental exercise and demanding cognitive tasks. Assessments took place on acute study days following a single dose (Day 1) of MVM, containing 3 times recommended daily allowance of water-soluble vitamins plus CoQ10, and following 4-week supplementation (Day 28).

Results

Energy expenditure (EE) was increased during cognitive tasks following MVM across Day 1 and Day 28, with greater effects in males. In males, MVM also increased carbohydrate oxidation and energy expenditure during exercise across Day 1 and Day 28. In females, mental tiredness was lower during exercise; increases in physical tiredness following 30 min of exercise were attenuated; and stress ratings following cognitive tasks were reduced following MVM. In males, MVM only lowered mental tiredness following 10 min of exercise. These effects were apparent irrespective of day, but effects on mental tiredness were greater on Day 28. Ferritin levels were also higher on Day 28 in those receiving MVM.

Conclusion

These findings extend on existing knowledge, demonstrating increased carbohydrate oxidation and increased energy expenditure in males following MVM supplementation for the first time. Importantly, they show modulation of energy expenditure and subjective tiredness following a single dose, providing further evidence for acute effects of MVM. Differential effects in men and women suggest that sex may play an important role in the effects of MVM on energy metabolism and should be considered in future research.

Trial registration

ClinicalTrials.gov, NCT03003442. Registered 22nd November 2016 – retrospectively registered

Crossbreeding with a tropically adapted Bos taurus breed (Senepol) to improve meat quality and production from Brahman herds in Northern Australia. 1. Steer performance

The performance of four year groups of Brahman and F1 Senepol × Brahman steers was compared grazing buffel pasture at the Douglas-Daly Research Farm, Douglas-Daly, NT, Australia. F1 Senepol × Brahman steers were on average 32 kg heavier at turnoff at ~18 months of age (P < 0.001) as a result of higher average weaning weights (+19 kg, P < 0.001) and higher growth during the post-weaning year (+12 kg, P < 0.001). These results, combined with previous studies that found that F1 Senepol × Brahman steers had more tender meat and performed better than Brahman in an Indonesian feedlot, indicate that crossbreeding with a tropically adapted Bos taurus breed, such as Senepol, could be an effective way for north Australian cattle producers with Brahman herds to produce cattle that perform well under northern conditions, and are suited to both the live export and domestic markets.

Development of plasmonic ELISA for the detection of anti-Leishmania sp. IgG antibodies

Recently, a novel Enzyme-Linked Immunosorbent Assay (ELISA) strategy has emerged, known as "plasmonic ELISA" (pELISA), which enables the detection of disease biomarkers at low concentrations with the naked eye. For the first time, this research has developed a signal-generation mechanism for the detection of anti-Leishmania sp. IgG antibodies with the naked eye using pELISA. The immunoassay incorporates an indirect ELISA with successive growth of gold nanoparticles to obtain blue or red-colored solutions in the presence or absence of anti-Leishmania sp. IgG antibodies in canine serum, respectively. The technique we developed was successfully tested in canine serum positive and negative for canine leishmaniasis (CanL), and was shown to be an effective method that could be used as an additional tool for CanL diagnosis. It will be particularly useful in resource-constrained countries, because it does not require sophisticated instruments to read the results, increasing the practicality of CanL detection in these areas.

Malaria vaccine candidate based on Duffy-binding protein elicits strain transcending functional antibodies in a Phase I trial

Reticulocyte invasion by Plasmodium vivax requires interaction of the Duffy-binding protein (PvDBP) with host Duffy antigen receptor for chemokines (DARCs). The binding domain of PvDBP maps to a cysteine-rich region referred to as region II (PvDBPII). Blocking this interaction offers a potential path to prevent P. vivax blood-stage growth and P. vivax malaria. This forms the rationale for development of a vaccine based on PvDBPII. Here we report results of a Phase I randomized trial to evaluate the safety and immunogenicity of recombinant PvDBPII formulated with glucopyranosyl lipid adjuvant-stable emulsion (GLA-SE). Thirty-six malaria-naive, healthy Indian male subjects aged 18-45 years were assigned into three cohorts corresponding to doses of 10, 25 and 50 µg of PvDBPII formulated with 5 µg of GLA-SE. Each cohort included nine PvDBPII/GLA-SE vaccinees and three hepatitis B control vaccine recipients. Each subject received the assigned vaccine intramuscularly on days 0, 28 and 56, and was followed up till day 180. No serious AE was reported and PvDBPII/GLA-SE was well-tolerated and safe. Analysis by ELISA showed that all three doses of PvDBPII elicited antigen-specific binding-inhibitory antibodies. The 50 µg dose elicited antibodies against PvDBPII that had the highest binding-inhibitory titres and were most persistent. Importantly, the antibody responses were strain transcending and blocked receptor binding of diverse PvDBP alleles. These results support further clinical development of PvDBPII/GLA-SE to evaluate efficacy against sporozoite or blood-stage challenge in controlled human malaria infection (CHMI) models and against natural P. vivax challenge in malaria endemic areas.

Abstract GS3-07: Genome-wide copy number analysis of chemotherapy-resistant metastatic triple-negative breast cancer from cell-free DNA

Introduction:

Triple-negative breast cancer (TNBC) is a poor prognosis breast cancer subset characterized by relatively few mutations but extensive copy number alterations (CNAs). Cell-free DNA (cfDNA) offers the potential to overcome infrequent tumor biopsies in metastatic TNBC (mTNBC) and interrogate the genomics of chemotherapy resistance.

Methods:

506 archival or fresh plasma samples were identified from 164 patients with mTNBC who had previously received chemotherapy. We performed low coverage whole genome sequencing to determine genome-wide copy number and estimate 'tumor fraction' of cfDNA (TFx) using our recently-developed approach, ichorCNA. In patient samples with TFx >10%, we identified regions that were significantly gained or lost using GISTIC2.0. We compared CNAs of 20 paired primary-metastatic samples and also mTNBCs from cfDNA versus primary TNBCs from TCGA and METABRIC.

Results:

We successfully obtained high quality, low coverage whole genome sequencing data for 478 (94.5%) plasma samples from 158 patients, with 1 to 14 samples per patient. TFx and copy number profiles were highly concordant with paired metastatic biopsy (n=10, range 0-7 days from biopsy to blood draw) with sensitivity of 0.86 and specificity of 0.90 and reproducible in independently-processed blood draws (TFx intraclass correlation coefficient 0.984). Median overall survival from time of first blood draw was 8 months, and TFx was highly correlated independent of primary stage, primary receptor status, age at primary diagnosis, BRCA status, and metastatic line of therapy: adjusted hazard ratio between 4th and 1st quartiles = 2.14 (95% CI 1.40-3.28; p=0.00049). 101/158 patients (63.9%) had at least one sample with TFx >10%, our threshold for high confidence CNA calls. Copy number profiles and percent genome altered were remarkably similar between mTNBCs and primary TNBCs in TCGA and METABRIC (n=433), suggesting that large-scale chromosomal events are infrequent in TNBC metastatic progression. We identified chromosomal gains that demonstrated significant enrichment in mTNBCs relative to paired primary TNBCs (n=20) and also TCGA/METABRIC, including driver genes (NOTCH2, AKT2, AKT3) and putative antibody-drug conjugate targets. Finally, we identify a novel association of gains of 18q11 and/or 19p13 with poor metastatic prognosis, independent of clinicopathologic factors and TFx.

Conclusions:

Here, we present the first large-scale genomic characterization of metastatic TNBC to our knowledge, derived exclusively from cfDNA. 'Tumor fraction' of cfDNA is an independent prognostic marker in mTNBC. Primary and metastatic TNBC have remarkably similar copy number profiles yet we identify alterations enriched and prognostic in mTNBC. Collectively, these data have potential implications in the understanding of metastasis, therapeutic resistance, and novel therapeutic targets.

Citation Format: Stover DG, Parsons HA, Ha G, Freeman S, Barry B, Guo H, Choudhury A, Gydush G, Reed S, Rhoades J, Rotem D, Hughes ME, Dillon DA, Partridge AH, Wagle N, Krop IE, Getz G, Golub TA, Love JC, Winer EP, Tolaney SM, Lin NU, Adalsteinsson VA. Genome-wide copy number analysis of chemotherapy-resistant metastatic triple-negative breast cancer from cell-free DNA [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr GS3-07.

Characterization of exosomes from body fluids of dairy cows

Exosomes are a specific subpopulation of extracellular vesicles that are widely released by cells of different origins with divergent functions that make their way into body fluids that can be conveniently sampled. In the current study, we isolated and evaluated exosomes from concurrently collected samples of milk, plasma, saliva, and urine from a group of 6 pregnant Holstein-Friesian dairy cows (aged 7 mo, 174 to 203 d of gestation). The cows had BCS of 3.5 to 5.25 (on a scale of 1 to 10), and the milk production for the season to the time of sampling ranged between 5,118 and 6,959 kg. The low levels of extracellular vesicles in saliva and urine (more than 86% fewer compared to the extracellular vesicles in milk and plasma) precluded further detailed evaluation since utility for diagnostics was deemed unlikely. In exosomes isolated from milk and plasma, size distribution, morphology, and the presence of exosome markers was confirmed by nanoparticle tracking analysis, electron microscopy, and Western blot. In addition, a targeted proteomic approach using the quadrupole ion trap mass spectrometer was also used in the study to screen for the exosome marker (e.g., Tumor susceptibility gene 101). Following confirmation of the presence of exosomes, the proteomic profiles of milk and plasma exosomes were evaluated using information-dependent acquisition-mediated liquid chromatography-tandem mass spectrometry (LC-MS/MS). The milk exosomes contain proteins that differed greatly from the plasma exosomes, with only 8 similar proteins harbored in both the milk and plasma exosomes. The milk and plasma exosomes were found to contain proteins (e.g., immunoglobulin J chain and α2 macroglobulin) associated with specific biological processes and molecular functions. Hence, the fluid of origin required for exosome analysis will be dependent on the specific information needed. In conclusion, isolated exosomes from milk and plasma samples collected at the same time point from the same dairy cows encapsulated different profiles of proteins associated with different biological processes and molecular functions.

Protein nanovaccine confers robust immunity against Toxoplasma

We designed and produced a self-assembling protein nanoparticle. This self-assembling protein nanoparticle contains five CD8+ HLA-A03-11 supertypes-restricted epitopes from antigens expressed during Toxoplasma gondii's lifecycle, the universal CD4+ T cell epitope PADRE, and flagellin as a scaffold and TLR5 agonist. These CD8+ T cell epitopes were separated by N/KAAA spacers and optimized for proteasomal cleavage. Self-assembling protein nanoparticle adjuvanted with TLR4 ligand-emulsion GLA-SE were evaluated for their efficacy in inducing IFN-γ responses and protection of HLA-A*1101 transgenic mice against T. gondii. Immunization, using self-assembling protein nanoparticle-GLA-SE, activated CD8+ T cells to produce IFN-γ. Self-assembling protein nanoparticle-GLA-SE also protected HLA-A*1101 transgenic mice against subsequent challenge with Type II parasites. Hence, combining CD8+ T cell-eliciting peptides and PADRE into a multi-epitope protein that forms a nanoparticle, administered with GLA-SE, leads to efficient presentation by major histocompatibility complex Class I and II molecules. Furthermore, these results suggest that activation of TLR4 and TLR5 could be useful for development of vaccines that elicit T cells to prevent toxoplasmosis in humans.

Fatal and serious collisions involving pedal cyclists and trucks in London between 2007 and 2011

OBJECTIVE

Increased numbers of people riding pedal cycles have led to a greater focus on pedal cycle safety. The aim of this article is to explore factors that are associated with fatal and a small number of serious-injury pedal cyclist crashes involving trucks that occurred in London between 2007 and 2011.

METHODS

Data were collected from police collision files for 53 crashes, 27 of which involved a truck (≥3.5 tonnes) and a pedal cycle. A systematic case review approach was used to identify the infrastructure, vehicle road user, and management factors that contributed to these crashes and injuries and how these factors interacted.

RESULTS

Trucks turning left conflicting with pedal cyclists traveling straight ahead was a common crash scenario. Key contributory factors identified included the pedal cyclists not being visible to the truck drivers, road narrowing, and inappropriate positioning of pedal cyclists.

CONCLUSIONS

Crashes involving trucks and pedal cyclists are complex events that are caused by multiple interacting factors; therefore, multiple measures are required to prevent them from occurring.

Effect of circulating exosomes from transition cows on Madin-Darby bovine kidney cell function

The greatest risk of metabolic and infectious disease in dairy cows is during the transition from pregnancy to lactating (i.e., the transition period). The objective of this experiment was to determine the effects of extracellular vesicles (microvesicles involved in cell-to-cell signaling) isolated from transition cows on target cell function. We previously identified differences in the protein profiles of exosomes isolated from cows divergent in metabolic health status. Therefore, we hypothesized that these exosomes would affect target tissues differently. To investigate this, 2 groups of cows (n = 5/group) were selected based on the concentration of β-hydroxybutyrate and fatty acids in plasma and triacylglycerol concentration in liver at wk 1 and 2 postcalving. Cows with high concentrations of β-hydroxybutyrate, fatty acids, and triacylglycerol were considered at increased risk of clinical disease during the transition period (high-risk group; n = 5) and were compared with cows that had low concentrations of the selected health indicators (low-risk group; n = 5). At 2 time points during the transition period (postcalving at wk 1 and 4), blood was sampled and plasma exosomes were isolated from the high-risk and low-risk cows. The exosomes were applied at concentrations of 10 and 1 µg/mL to 5 × 10³ Madin-Darby bovine kidney cells grown to 50% confluence in 96-well plates. Results indicate a numerical increase in cell proliferation when exosomes from high-risk cows were applied compared with those from low-risk cows. Consistent with an effect on cell proliferation, quantitative reverse transcriptase PCR indicated a trend for upregulation of 3 proinflammatory genes (granulocyte colony-stimulating factor, ciliary neurotrophic factor, and CD27 ligand) with the application of high-risk exosomes, which are involved in cellular growth and survival. Proteomic analysis indicated 2 proteins in the low-risk group that were not identified in the high-risk group (endoplasmin and catalase), which may also be indicative of the metabolic state of origin. It is likely that the metabolic state of the transition cow affects cellular function through exosomal messaging; however, more in-depth research into cross-talk between exosomes and target cells is required to determine whether exosomes influence Madin-Darby bovine kidney cells in this manner.

Recombinant polymorphic membrane protein D in combination with a novel, second-generation lipid adjuvant protects against intra-vaginal Chlamydia trachomatis infection in mice

•

rPmpD in combination with SLA elicits significant protection against intra-vaginal Ct challenge.

•

Antibodies induced by immunisation with rPmpD recognise Ct elementary bodies.

•

SLA is a novel adjuvant class that may be widely used in future preclinical Ct vaccine development.

The development of a chlamydial vaccine that elicits protective mucosal immunity is of paramount importance in combatting the global spread of sexually transmitted Chlamydia trachomatis (Ct) infections. While the identification and prioritization of chlamydial antigens is a crucial prerequisite for efficacious vaccine design, it is likely that novel adjuvant development and selection will also play a pivotal role in the translational potential of preclinical Ct vaccines. Although the molecular nature of the immuno-modulatory component is of primary importance, adjuvant formulation and delivery systems may also govern vaccine efficacy and potency. Our study provides the first preclinical evaluation of recombinant Ct polymorphic membrane protein D (rPmpD) in combination with three different formulations of a novel second-generation lipid adjuvant (SLA). SLA was rationally designed in silico by modification of glucopyranosyl lipid adjuvant (GLA), a TLR4 agonistic precursor molecule currently in Phase II clinical development. We demonstrate robust protection against intra-vaginal Ct challenge in mice, evidenced by significantly enhanced resistance to infection and reduction in mean bacterial load. Strikingly, protection was found to correlate with the presence of robust anti-rPmpD serum and cervico-vaginal IgG titres, even in the absence of adjuvant-induced Th1-type cellular immune responses elicited by each SLA formulation, and we further show that anti-rPmpD antibodies recognize Ct EBs. These findings highlight the utility of SLA and rational molecular design of adjuvants in preclinical Ct vaccine development, but also suggest an important role for anti-rPmpD antibodies in protection against urogenital Ct infection.

Plasma exosome profiles from dairy cows with divergent fertility phenotypes

Cell-to-cell communication in physiological and pathological conditions may be influenced by neighboring cells, distant tissues, or local environmental factors. Exosomes are specific subsets of extracellular vesicles that internalize and deliver their content to near and distant sites. Exosomes may play a role in the maternal-embryo crosstalk vital for the recognition and maintenance of a pregnancy; however, their role in dairy cow reproduction has not been established. This study aimed to characterize the exosome profile in the plasma of 2 strains of dairy cow with divergent fertility phenotypes. Plasma was obtained and characterized on the basis of genetic ancestry as fertile (FERT; <23% North American genetics, New Zealand Holstein-Friesian strain, n=8) or subfertile (SUBFERT; >92% North American genetics, North American Holstein-Friesian strain, n=8). Exosomes were isolated by differential and buoyant density centrifugation and characterized by size distribution (nanoparticle tracking analysis, NanoSight NS500, NanoSight Ltd., Amesbury, UK), the presence of CD63 (Western blot), and their morphology (electron microscopy). The total number of exosomes was determined by quantifying the immunoreactive CD63 (ExoELISA kit, System Biosciences), and the protein content established by mass spectrometry. Enriched exosome fractions were identified as cup-shape vesicles with diameters around 100 nm and positive for the CD63 marker. The concentration of exosomes was 50% greater in FERT cows. Mass spectrometry identified 104 and 117 proteins in FERT and SUBFERT cows, of which 23 and 36 were unique, respectively. Gene ontology analysis revealed enrichment for proteins involved in immunomodulatory processes and cell-to-cell communication. Although the role of exosomes in dairy cow reproduction remains to be elucidated, their quantification and content in models with divergent fertility phenotypes could provide novel information to support both physiological and genetic approaches to improving dairy cow fertility.

Targeting HIV-1 Env gp140 to LOX-1 Elicits Immune Responses in Rhesus Macaques

Improved antigenicity against HIV-1 envelope (Env) protein is needed to elicit vaccine-induced protective immunity in humans. Here we describe the first tests in non-human primates (NHPs) of Env gp140 protein fused to a humanized anti-LOX-1 recombinant antibody for delivering Env directly to LOX-1-bearing antigen presenting cells, especially dendritic cells (DC). LOX-1, or 1ectin-like oxidized low-density lipoprotein (LDL) receptor-1, is expressed on various antigen presenting cells and endothelial cells, and is involved in promoting humoral immune responses. The anti-LOX-1 Env gp140 fusion protein was tested for priming immune responses and boosting responses in animals primed with replication competent NYVAC-KC Env gp140 vaccinia virus. Anti-LOX-1 Env gp140 vaccination elicited robust cellular and humoral responses when used for either priming or boosting immunity. Co-administration with Poly ICLC, a TLR3 agonist, was superior to GLA, a TLR4 agonist. Both CD4+ and CD8+ Env-specific T cell responses were elicited by anti-LOX-1 Env gp140, but in particular the CD4+ T cells were multifunctional and directed to multiple epitopes. Serum IgG and IgA antibody responses induced by anti-LOX-1 Env gp140 against various gp140 domains were cross-reactive across HIV-1 clades; however, the sera neutralized only HIV-1 bearing sequences most similar to the clade C 96ZM651 Env gp140 carried by the anti-LOX-1 vehicle. These data, as well as the safety of this protein vaccine, justify further exploration of this DC-targeting vaccine approach for protective immunity against HIV-1.

Radiation doses from fluoroscopically guided cardiac catheterization procedures in children and young adults in the United Kingdom: a multicentre study

OBJECTIVE

To gather data on radiation doses from fluoroscopically guided cardiac catheterization procedures in patients aged under 22 years at multiple centres and over a prolonged period in the UK. To evaluate and explain variation in doses. To estimate patient-specific organ doses and allow for possible future epidemiological analysis of associated cancer risks.

METHODS

Patient-specific data including kerma area product and screening times from 10,257 procedures carried out on 7726 patients at 3 UK hospitals from 1994 until 2013 were collected. Organ doses were estimated from these data using a dedicated dosimetry system based on Monte Carlo computer simulations.

RESULTS

Radiation doses from these procedures have fallen significantly over the past two decades. The organs receiving the highest doses per procedure were the lungs (median across whole cohort, 20.5 mSv), heart (19.7 mSv) and breasts (13.1 mSv). Median cumulative doses, taking into account multiple procedures, were 23.2, 22.2 and 16.7 mSv for these organs, respectively. Bone marrow doses were relatively low (median per procedure, 3.2 mSv; cumulative, 3.6 mSv).

CONCLUSION

Most modern cardiac catheterizations in children are moderately low-dose procedures. Technological advances appear to be the single most important factor in the fall in doses. Patients undergoing heart transplants undergo the most procedures. An epidemiological assessment of cancer risks following these procedures may be possible, especially using older data when doses were higher.

ADVANCES IN KNOWLEDGE

This is the first large-scale, patient-specific assessment of organ doses from these procedures in a young population.

NEOCENT: a randomised feasibility and translational study comparing neoadjuvant endocrine therapy with chemotherapy in ER-rich postmenopausal primary breast cancer

Neoadjuvant endocrine therapy is an alternative to chemotherapy for women with oestrogen receptor (ER)-positive early breast cancer (BC). We aimed to assess feasibility of recruiting patients to a study comparing chemotherapy versus endocrine therapy in postmenopausal women with ER-rich primary BC, and response as well as translational endpoints were assessed. Patients requiring neoadjuvant therapy were randomised to chemotherapy: 6 × 3-weekly cycles FE₁₀₀C or endocrine therapy: letrozole 2.5 mg, daily for 18-23 weeks. Primary endpoints were recruitment feasibility and tissue collection. Secondary endpoints included clinical, radiological and pathological response rates, quality of life and translational endpoints. 63/80 patients approached were eligible, of those 44 (70, 95% CI 57-81) were randomised. 12 (54.5, 95% CI 32.2-75.6) chemotherapy patients showed radiological objective response compared with 13 (59.1, 95% CI 36.4-79.3) letrozole patients. Compared with baseline, mean Ki-67 levels fell in both groups at days 2-4 and at surgery [fold change: 0.24 (95% CI 0.12-0.51) and 0.24; (95% CI 0.15-0.37), respectively]. Plasma total cfDNA levels rose from baseline to week 8 [fold change: chemotherapy 2.10 (95% CI 1.47-3.00), letrozole 1.47(95% CI 0.98-2.20)], and were maintained at surgery in the chemotherapy group [chemotherapy 2.63; 95% CI 1.56-4.41), letrozole 0.95 (95% CI 0.71-1.26)]. An increase in plasma let-7a miRNA was seen at surgery for patients with objective radiological response to chemotherapy. Recruitment and tissue collection endpoints were met; however, a larger trial was deemed unfeasible due to slow accrual. Both regimens were equally efficacious. Dynamic changes were seen in Ki-67 and circulating biomarkers in both groups with increases in cfDNA and let-7a miRNA persisting until surgery for chemotherapy patients.