Cek1 regulates ß(1,3)-glucan exposure through calcineurin effectors in Candida albicans.

In order to successfully induce disease, the fungal pathogen Candida albicans regulates exposure of antigens like the cell wall polysaccharide ß(1,3)-glucan to the host immune system. C. albicans covers (masks) ß(1,3)-glucan with a layer of mannosylated glycoproteins, which aids in immune system evasion by acting as a barrier to recognition by host pattern recognition receptors. Consequently, enhanced ß(1,3)-glucan exposure (unmasking) makes fungal cells more visible to host immune cells and facilitates more robust fungal clearance. However, an understanding of how C. albicans regulates its exposure levels of ß(1,3)-glucan is needed to leverage this phenotype. Signal transduction pathways and their corresponding effector genes mediating these changes are only beginning to be defined. Here, we report that the phosphatase calcineurin mediates unmasking of ß(1,3)-glucan in response to inputs from the Cek1 MAPK pathway and in response to caspofungin exposure. In contrast, calcineurin reduces ß-glucan exposure in response to high levels of extracellular calcium. Thus, depending on the input, calcineurin acts as a switchboard to regulate ß(1,3)-glucan exposure levels. By leveraging these differential ß(1,3)-glucan exposure phenotypes, we identified two novel effector genes in the calcineurin regulon, FGR41 and C1_11990W_A, that encode putative cell wall proteins and mediate masking/unmasking. Loss of either effector caused unmasking and attenuated virulence during systemic infection in mice. Furthermore, immunosuppression restored the colonization decrease seen in mice infected with the fgr41Δ/Δ mutant to wild-type levels, demonstrating a reliance on the host immune system for virulence attenuation. Thus, calcineurin and its downstream regulon are general regulators of unmasking.

Possible Cross-Reactivity of Feline and White-Tailed Deer Antibodies against the SARS-CoV-2 Receptor Binding Domain.

In late 2019, a novel coronavirus began circulating within humans in central China. It was designated SARS-CoV-2 because of its genetic similarities to the 2003 SARS coronavirus (SARS-CoV). Now that SARS-CoV-2 has spread worldwide, there is a risk of it establishing new animal reservoirs and recombination with native circulating coronaviruses. To screen local animal populations in the United States for exposure to SARS-like coronaviruses, we developed a serological assay using the receptor binding domain (RBD) from SARS-CoV-2. SARS-CoV-2's RBD is antigenically distinct from common human and animal coronaviruses, allowing us to identify animals previously infected with SARS-CoV or SARS-CoV-2. Using an indirect enzyme-linked immunosorbent assay (ELISA) for SARS-CoV-2's RBD, we screened serum from wild and domestic animals for the presence of antibodies against SARS-CoV-2's RBD. Surprisingly prepandemic feline serum samples submitted to the University of Tennessee Veterinary Hospital were ∼50% positive for anti-SARS RBD antibodies. Some of these samples were serologically negative for feline coronavirus (FCoV), raising the question of the etiological agent generating anti-SARS-CoV-2 RBD cross-reactivity. We also identified several white-tailed deer from South Carolina with anti-SARS-CoV-2 antibodies. These results are intriguing, as cross-reactive antibodies toward SARS-CoV-2 RBD have not been reported to date. The etiological agent responsible for seropositivity was not readily apparent, but finding seropositive cats prior to the current SARS-CoV-2 pandemic highlights our lack of information about circulating coronaviruses in other species. IMPORTANCE We report cross-reactive antibodies from prepandemic cats and postpandemic South Carolina white-tailed deer that are specific for that SARS-CoV RBD. There are several potential explanations for this cross-reactivity, each with important implications to coronavirus disease surveillance. Perhaps the most intriguing possibility is the existence and transmission of an etiological agent (such as another coronavirus) with similarity to SARS-CoV-2's RBD region. However, we lack conclusive evidence of prepandemic transmission of a SARS-like virus. Our findings provide impetus for the adoption of a One Health Initiative focusing on infectious disease surveillance of multiple animal species to predict the next zoonotic transmission to humans and future pandemics.

Activation of Cph1 causes ß(1,3)-glucan unmasking in Candida albicans and attenuates virulence in mice in a neutrophil-dependent manner.

Masking the immunogenic cell wall epitope ß(1,3)-glucan under an outer layer of mannosylated glycoproteins is an important virulence factor deployed by Candida albicans during infection. Consequently, increased ß(1,3)-glucan exposure (unmasking) reveals C. albicans to the host's immune system and attenuates its virulence. We have previously shown that activation of the Cek1 MAPK pathway via expression of a hyperactive allele of an upstream kinase (STE11ΔN467) induced unmasking. It also increased survival of mice in a murine disseminated candidiasis model and attenuated kidney fungal burden by ≥33 fold. In this communication, we utilized cyclophosphamide-induced immunosuppression to test if the clearance of the unmasked STE11ΔN467 mutant was dependent on the host immune system. Suppression of the immune response by cyclophosphamide reduced the attenuation in fungal burden caused by the STE11ΔN467 allele. Moreover, specific depletion of neutrophils via 1A8 antibody treatment also reduced STE11ΔN467-dependent fungal burden attenuation, but to a lesser extent than cyclophosphamide, demonstrating an important role for neutrophils in mediating fungal clearance of unmasked STE11ΔN467 cells. In an effort to understand the mechanism by which Ste11ΔN467 causes unmasking, transcriptomics were used to reveal that several components in the Cek1 MAPK pathway were upregulated, including the transcription factor CPH1 and the cell wall sensor DFI1. In this report we show that a cph1ΔΔ mutation restored ß(1,3)-glucan exposure to wild-type levels in the STE11ΔN467 strain, confirming that Cph1 is the transcription factor mediating Ste11ΔN467-induced unmasking. Furthermore, Cph1 is shown to induce a positive feedback loop that increases Cek1 activation. In addition, full unmasking by STE11ΔN467 is dependent on the upstream cell wall sensor DFI1. However, while deletion of DFI1 significantly reduced Ste11ΔN467-induced unmasking, it did not impact activation of the downstream kinase Cek1. Thus, it appears that once stimulated by Ste11ΔN467, Dfi1 activates a parallel signaling pathway that is involved in Ste11ΔN467-induced unmasking.

Beyond net-zero: Toward a "One Planet" health system.

Climate change has captured much attention, but it is just one part of a much larger set of massive and rapid global ecological changes. While the United Nations has taken to referring to the "triple planetary crisis" of climate change, biodiversity loss, and pollution, even this does not capture the full extent of human impact upon the Earth-and thus upon human well-being. Canada's ecological footprint is equivalent to five planets worth of biocapacity, and healthcare's footprint is probably greater. So while health systems need to become low-carbon or net-zero, they need to go further. If healthcare is to stand by its ethical duty to do no harm, it must become a "One Planet" system. In addition to becoming a net-zero system, healthcare must reduce the consumption of material resources, the use of toxic substances, and production of all forms of waste, and protect and restore nature.

Exiting the Anthropocene: Achieving personal and planetary health in the 21st century.

Planetary health provides a perspective of ecological interdependence that connects the health and vitality of individuals, communities, and Earth's natural systems. It includes the social, political, and economic ecosystems that influence both individuals and whole societies. In an era of interconnected grand challenges threatening health of all systems at all scales, planetary health provides a framework for cross-sectoral collaboration and unified systems approaches to solutions. The field of allergy is at the forefront of these efforts. Allergic conditions are a sentinel measure of environmental impact on human health in early life-illuminating how ecological changes affect immune development and predispose to a wider range of inflammatory noncommunicable diseases (NCDs). This shows how adverse macroscale ecology in the Anthropocene penetrates to the molecular level of personal and microscale ecology, including the microbial systems at the foundations of all ecosystems. It provides the basis for more integrated efforts to address widespread environmental degradation and adverse effects of maladaptive urbanization, food systems, lifestyle behaviors, and socioeconomic disadvantage. Nature-based solutions and efforts to improve nature-relatedness are crucial for restoring symbiosis, balance, and mutualism in every sense, recognizing that both personal lifestyle choices and collective structural actions are needed in tandem. Ultimately, meaningful ecological approaches will depend on placing greater emphasis on psychological and cultural dimensions such as mindfulness, values, and moral wisdom to ensure a sustainable and resilient future.

Priorities among effective clinical preventive services in British Columbia, Canada.

BACKGROUND: Despite the long-standing experience of rating the evidence for clinical preventive services, the delivery of effective clinical preventive services in Canada and elsewhere is less than optimal. We outline an approach used in British Columbia to assist in determining which effective clinical preventive services are worth doing. METHODS: We calculated the clinically preventable burden and cost-effectiveness for 28 clinical preventive services that received a 'strong or conditional (weak) recommendation for' by the Canadian Task Force on Preventive Health Care or an 'A' or 'B' rating by the United States Preventive Services Task Force. Clinically preventable burden is the total quality adjusted life years that could be gained if the clinical preventive services were delivered at recommended intervals to a British Columbia birth cohort of 40,000 individuals over the years of life that the service is recommended. Cost-effectiveness is the net cost per quality adjusted life year gained. RESULTS: Clinical preventive services with the highest population impact and best value for money include services that address tobacco use in adolescents and adults, exclusive breastfeeding, and screening for hypertension and other cardiovascular disease risk factors followed by appropriate pharmaceutical treatment. In addition, alcohol misuse screening and brief counseling, one-time screening for hepatitis C virus infection in British Columbia adults born between 1945 and 1965, and screening for type 2 diabetes approach these high-value clinical preventive services. CONCLUSIONS: These results enable policy makers to say with some confidence what preventive manoeuvres are worth doing but further work is required to determine the best way to deliver these services to all those eligible and to establish what supportive services are required. After all, if a clinical preventive service is worth doing, it is worth doing well.

Towards healthy One Planet cities and communities: planetary health promotion at the local level.

Health promotion has paid a lot of attention to the social determinants of health and to health equity but much less attention to the ecological determinants. Yet the most fundamental determinants of health are the natural systems that make the Earth liveable and are the source of our air, water, food, fuels and materials. Yet they are threatened by the very economic and social development that we have created to meet the social determinants of health. Moreover, the benefits and burdens of that development are inequitably distributed, resulting in both ecological and social injustice. In the past few years the new field of planetary health-'the health of human civilization and the state of the natural systems on which it depends'-has emerged, while WHO has confirmed that 'the source of human health [is] nature'. So arguably the most important task facing health promotion in the 21st century is to turn its attention to planetary health: health promotion workers must become planetary health promoters. Local health promotion in the 21st century needs to incorporate the concept of planetary health promotion and its application in the creation of healthy 'One Planet' communities and must become part of the emerging network of community organizations and individuals working to create sustainable, just and healthy communities.

Critical considerations for the practical utility of health equity tools: a concept mapping study.

BACKGROUND: Promoting health equity within health systems is a priority and challenge worldwide. Health equity tools have been identified as one strategy for integrating health equity considerations into health systems. Although there has been a proliferation of health equity tools, there has been limited attention to evaluating these tools for their practicality and thus their likelihood for uptake. METHODS: Within the context of a large program of research, the Equity Lens in Public Health (ELPH), we conducted a concept mapping study to identify key elements and themes related to public health leaders and practitioners' views about what makes a health equity tool practical and useful. Concept mapping is a participatory mixed-method approach to generating ideas and concepts to address a common concern. Participants brainstormed responses to the prompt "To be useful, a health equity tool should…" After participants sorted responses into groups based on similarity and rated them for importance and feasibility, the statements were analyzed using multidimensional scaling, then grouped using cluster analysis. Pattern matching graphs were constructed to illustrate the relationship between the importance and feasibility of statements, and go-zone maps were created to guide subsequent action. RESULTS: The process resulted in 67 unique statements that were grouped into six clusters: 1) Evaluation for Improvement; 2) User Friendliness; 3) Explicit Theoretical Background; 4) Templates and Tools 5) Equity Competencies; and 6) Nothing about Me without Me- Client Engaged. The result was a set of concepts and themes describing participants' views of the practicality and usefulness of health equity tools. CONCLUSIONS: These thematic clusters highlight the importance of user friendliness and having user guides, templates and resources to enhance use of equity tools. Furthermore, participants' indicated that practicality was not enough for a tool to be useful. In addition to practical characteristics of the tool, a useful tool is one that encourages and supports the development of practitioner competencies to engage in equity work including critical reflections on power and institutional culture as well as strategies for the involvement of community members impacted by health inequities in program planning and delivery. The results of this study will be used to inform the development of practical criteria to assess health equity tools for application in public health.

Healthcare in the Anthropocene: Challenges and Opportunities.

We are entering the Anthropocene. So large is our impact on the planet that Earth scientists suggest our presence will show up in the geologic record far into the future. The global ecological changes we are creating pose a threat to health not only from climate change but from pollution and ecotoxicity, ocean acidification, resource depletion and the loss of biodiversity that threatens a sixth "Great Extinction." These health threats will impose an added burden on the healthcare system, while the ecological changes will force it to adapt to the new realities. The healthcare system contributes to these changes. It is an energy and resource-intensive part of society that also produces large volumes of solid and liquid wastes and air pollutants, some of them quite toxic; the system has a large ecological footprint; yet, at the same time, the system has an ethical duty to do no harm, and thus should be a leader in the transition to a more ecologically sustainable and healthier future.

Reducing health inequities: the contribution of core public health services in BC.

BACKGROUND: Within Canada, many public health leaders have long identified the importance of improving the health of all Canadians especially those who face social and economic disadvantages. Future improvements in population health will be achieved by promoting health equity through action on the social determinants of health. Many Canadian documents, endorsed by government and public health leaders, describe commitments to improving overall health and promoting health equity. Public health has an important role to play in strengthening action on the social determinants and promoting health equity. Currently, public health services in British Columbia are being reorganized and there is a unique opportunity to study the application of an equity lens in public health and the contribution of public health to reducing health inequities. Where applicable, we have chosen mental health promotion, prevention of mental disorders and harms of substance use as exemplars within which to examine specific application of an equity lens. METHODS/DESIGN: This research protocol is informed by three theoretical perspectives: complex adaptive systems, critical social justice, and intersectionality. In this program of research, there are four inter-related research projects with an emphasis on both integrated and end of grant knowledge translation. Within an overarching collaborative and participatory approach to research, we use a multiple comparative case study research design and are incorporating multiple methods such as discourse analysis, situational analysis, social network analysis, concept mapping and grounded theory. DISCUSSION: An important aim of this work is to help ensure a strong public health system that supports public health providers to have the knowledge, skills, tools and resources to undertake the promotion of health equity. This research will contribute to increasing the effectiveness and contributions of public health in reducing unfair and inequitable differences in health among population groups. As a collaborative effort between public health practitioners/decision makers and university researchers, this research will provide important understanding and insights about the implementation of the changes in public health with a specific focus on health equity, the promotion of mental health and the prevention of harms of substance use.

A secreted sirtuin from Campylobacter jejuni contributes to neutrophil activation and intestinal inflammation during infection.

Histone modifications control numerous processes in eukaryotes, including inflammation. Some bacterial pathogens alter the activity or expression of host-derived factors, including sirtuins, to modify histones and induce responses that promote infection. In this study, we identified a deacetylase encoded by Campylobacter jejuni which has sirtuin activities and contributes to activation of human neutrophils by the pathogen. This sirtuin is secreted from the bacterium into neutrophils, where it associates with and deacetylates host histones to promote neutrophil activation and extracellular trap production. Using the murine model of campylobacteriosis, we found that a mutant of this bacterial sirtuin efficiently colonized the gastrointestinal tract but was unable to induce cytokine production, gastrointestinal inflammation, and tissue pathology. In conclusion, these results suggest that secreted bacterial sirtuins represent a previously unreported class of bacterial effector and that bacterial-mediated modification of host histones is responsible for the inflammation and pathology that occurs during campylobacteriosis.

Development and characterization of a prototypic pan-amyloid clearing agent - a novel murine peptide-immunoglobulin fusion.

Introduction: Systemic amyloidosis is a progressive disorder characterized by the extracellular deposition of amyloid fibrils and accessory proteins in visceral organs and tissues. Amyloid accumulation causes organ dysfunction and is not generally cleared by the immune system. Current treatment focuses on reducing amyloid precursor protein synthesis and slowing amyloid deposition. However, curative interventions will likely also require removal of preexisting amyloid deposits to restore organ function. Here we describe a prototypic pan-amyloid binding peptide-antibody fusion molecule (mIgp5) that enhances macrophage uptake of amyloid. Methods: The murine IgG1-IgG2a hybrid immunoglobulin with a pan amyloid-reactive peptide, p5, fused genetically to the N-terminal of the immunoglobulin light chain was synthesized in HEK293T/17 cells. The binding of the p5 peptide moiety was assayed using synthetic amyloid-like fibrils, human amyloid extracts and amyloid-laden tissues as substrates. Binding of radioiodinated mIgp5 with amyloid deposits in vivo was evaluated in a murine model of AA amyloidosis using small animal imaging and microautoradiography. The bioactivity of mIgp5 was assessed in complement fixation and in vitro phagocytosis assays in the presence of patient-derived amyloid extracts and synthetic amyloid fibrils as substrates and in the presence or absence of human serum. Results: Murine Igp5 exhibited highly potent binding to AL and ATTR amyloid extracts and diverse types of amyloid in formalin-fixed tissue sections. In the murine model of systemic AA amyloidosis, 125I-mIgp5 bound rapidly and specifically to amyloid deposits in all organs, including the heart, with no evidence of non-specific uptake in healthy tissues. The bioactivity of the immunoglobulin Fc domain was uncompromised in the context of mIgp5 and served as an effective opsonin. Macrophage-mediated uptake of amyloid extract and purified amyloid fibrils was enhanced by the addition of mIgp5. This effect was exaggerated in the presence of human serum coincident with deposition of complement C5b9. Conclusion: Immunostimulatory, amyloid-clearing therapeutics can be developed by incorporating pan-amyloid-reactive peptides, such as p5, as a targeting moiety. The immunologic functionality of the IgG remains intact in the context of the fusion protein. These data highlight the potential use of peptide-antibody fusions as therapeutics for all types of systemic amyloidosis.