Art centres supporting our Elders - 'old people, that's where our strength comes from' - results from a national survey of Australian Aboriginal and Torres Strait Islander community controlled art centres.

INTRODUCTION: There are approximately 90 Aboriginal and Torres Strait Islander community controlled art centres across Australia, the majority in geographically remote locations. This survey explored how these centres are supporting older people, including people living with dementia, if and how they are collaborating with aged care services and what challenges and opportunities they identify in these arrangements. METHODS: An online survey was developed by a team of Aboriginal and non-Aboriginal researchers, art centre staff and art centre consultants. The survey was distributed in 2018 to art centres across Australia via their four art centre peak bodies: Desart; the Association of Northern, Kimberley and Arnhem Aboriginal Artists; the Indigenous Art Centre Alliance - Far North Queensland and Torres Strait Islands; and the Aboriginal Art Centre Hub - Western Australia. The survey was also conducted face-to-face with participants at art centre annual events; and on field trips to North Western and Central Australia, conducted as part of an overarching study. RESULTS: There were 53 completed surveys, with the highest proportion of responses (43%) from art centre managers. The survey generated 330 qualitative responses to the 13 questions that provided this option. The results showed that art centres play a wide ranging and vital role in supporting the health and wellbeing of older artists, many of whom are considered Elders within their communities, and that this reaches far beyond the production of art. The results showed that art centres are a safe place providing older people with the purpose and means to generate income, to enact governance, and to share cultural knowledge through intergenerational connection. Additionally, the results indicate that art centres provide a significant amount of direct care for older people, and that relationships are fundamental to delivering this social, emotional, spiritual and physical care. Furthermore, they showed a great deal of collaboration between art centres and aged care services, although little of this is formally documented or resourced. CONCLUSION: The survey results demonstrate that art centres play a significant and previously unexplored role in supporting the wellbeing of older people and people living with dementia in remote Aboriginal and Torres Strait Islander communities across Australia. Respondents shared diverse examples of providing physical, social, emotional, spiritual and cultural care, assistance with navigating health and aged care systems, as well as examples of collaborations with aged care and health providers. The results demonstrate opportunities to recognise and resource this vital work. These findings are particularly important in the context of Australia's recent Royal Commission into Aged Care Quality and Safety, which found that systemic change is urgently required. Additionally, Indigenous scholars have called for a swell of system reform to address inequities in health and aged care systems. They advocate for a fundamental shift from biomedical and siloed models of care to integrated models that centralise culture, intergenerational connection and the cultural determinants of health. The results show that art centres could bring their expertise to this conversation.

Determination of Active Phagocytosis of Unopsonized Porphyromonas gingivalis by Macrophages and Neutrophils Using the pH-Sensitive Fluorescent Dye pHrodo.

Phagocytosis of pathogens is an important component of the innate immune system that is responsible for the removal and degradation of bacteria as well as their presentation via the major histocompatibility complexes to the adaptive immune system. The periodontal pathogen Porphyromonas gingivalis exhibits strain heterogeneity, which may affect a phagocyte's ability to recognize and phagocytose the bacterium. In addition, P. gingivalis is reported to avoid phagocytosis by antibody and complement degradation and by invading phagocytic cells. Previous studies examining phagocytosis have been confounded by both the techniques employed and the potential of the bacteria to invade the cells. In this study, we used a novel, pH-sensitive dye, pHrodo, to label live P. gingivalis strains and examine unopsonized phagocytosis by murine macrophages and neutrophils and human monocytic cells. All host cells examined were able to recognize and phagocytose unopsonized P. gingivalis strains. Macrophages had a preference to phagocytose P. gingivalis strain ATCC 33277 over other strains and clinical isolates in the study, whereas neutrophils favored P. gingivalis W50, ATCC 33277, and one clinical isolate over the other strains. This study revealed that all P. gingivalis strains were capable of being phagocytosed without prior opsonization with antibody or complement.

Tannerella forsythia Outer Membrane Vesicles Are Enriched with Substrates of the Type IX Secretion System and TonB-Dependent Receptors.

Tannerella forsythia, a Gram-negative oral bacterium closely associated with chronic periodontitis, naturally produces outer membrane vesicles (OMVs). In this study, OMVs were purified by gradient centrifugation, and the proteome was investigated together with cellular fractions using LC-MS/MS analyses of SDS-PAGE fractions, resulting in the identification of 872 proteins including 297 OMV proteins. Comparison of the OMV proteome with the subcellular proteomes led to the localization of 173 proteins to the vesicle membrane and 61 proteins to the vesicle lumen, while 27 substrates of the type IX secretion system were assigned to the vesicle surface. These substrates were generally enriched in OMVs; however, the stoichiometry of the S-layer proteins, TfsA and TfsB, was significantly altered, potentially to accommodate the higher curvature required of the S-layer around OMVs. A vast number of TonB-dependent receptors related to SusC, together with their associated SusD-like lipoproteins, were identified, and these were also relatively enriched in OMVs. In contrast, other lipoproteins were significantly depleted from the OMVs. This study identified the highest number of membrane-associated OMV proteins to date in any bacterium and conclusively demonstrates cargo sorting of particular classes of proteins, which may have significant impact on the virulence of OMVs.

Porphyromonas gingivalis outer membrane vesicles exclusively contain outer membrane and periplasmic proteins and carry a cargo enriched with virulence factors.

Porphyromonas gingivalis, a keystone pathogen associated with chronic periodontitis, produces outer membrane vesicles (OMVs) that carry a cargo of virulence factors. In this study, the proteome of OMVs was determined by LC-MS/MS analyses of SDS-PAGE fractions, and a total of 151 OMV proteins were identified, with all but one likely to have originated from either the outer membrane or periplasm. Of these, 30 exhibited a C-terminal secretion signal known as the CTD that localizes them to the cell/vesicle surface, 79 and 27 were localized to the vesicle membrane and lumen respectively while 15 were of uncertain location. All of the CTD proteins along with other virulence factors were found to be considerably enriched in the OMVs, while proteins exhibiting the OmpA peptidoglycan-binding motif and TonB-dependent receptors were preferentially retained on the outer membrane of the cell. Cryo-transmission electron microscopy analysis revealed that an electron dense surface layer known to comprise CTD proteins accounted for a large proportion of the OMVs' volume providing an explanation for the enrichment of CTD proteins. Together the results show that P. gingivalis is able to specifically concentrate and release a large number of its virulence factors into the environment in the form of OMVs.

Aboriginal community-controlled art centres: Keeping Elders strong and connected. Articulating an ontologically situated, intergenerational model of care.

OBJECTIVE: To articulate how Aboriginal community-controlled art centres support the role of Elders and older people within an ontologically situated, intergenerational model of care. METHODS: In this paper, we draw on stories (data) generated through interviews involving 75 people associated with three Aboriginal community-controlled art centres and field notes taken during a Participatory Action Research (PAR) study. The study was undertaken in collaboration with three community-controlled art centres and two aged care providers over almost 4 years, in diverse Indigenous sovereignties, all located in geographically remote Australian locations. RESULTS: Engaging with decolonising and Indigenous theoretical frameworks, our analysis identified three interwoven meta-themes. These include connection to law and culture; purpose; and healing. Each theme had important subthemes, and all were central to upholding the well-being of older people and their families, as well as the art centre workforce, Country, and their broader communities. CONCLUSIONS: Our analysis articulates an ontologically situated model of care within Aboriginal community-controlled art centres. The model sees that older people receive care from art centres and provide care to each other, to younger generations, to art centre staff, to Country, and to their broader communities. In this model, those in receipt of care, many of whom are older people, art centre directors, and important artists, govern how care is conceptualised and delivered.

Outer Membrane Vesicle-Host Cell Interactions.

Outer membrane vesicles (OMVs) are nanosized proteoliposomes derived from the outer membrane of Gram-negative bacteria. They are ubiquitously produced both in culture and during infection and are now recognized to play crucial roles during host-microbe interactions. OMVs can transport a broad range of chemically diverse cargoes, including lipids and lipopolysaccharides, membrane-embedded and associated proteins and small molecules, peptidoglycan, and nucleic acids. Particularly, virulence factors such as adhesins and toxins are often enriched in OMVs. Here we discuss a variety of ways in which OMVs facilitate host-microbe interactions, including their contributions to biofilm formation, nutrient scavenging, and modulation of host cell function. We particularly examine recent findings regarding OMV-host cell interactions in the oral cavity and the gastrointestinal tract.

Outer Membrane Vesicles Prime and Activate Macrophage Inflammasomes and Cytokine Secretion In Vitro and In Vivo.

Outer membrane vesicles (OMVs) are proteoliposomes blebbed from the surface of Gram-negative bacteria. Chronic periodontitis is associated with an increase in subgingival plaque of Gram-negative bacteria, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia. In this study, we investigated the immune-modulatory effects of P. gingivalis, T. denticola, and T. forsythia OMVs on monocytes and differentiated macrophages. All of the bacterial OMVs were phagocytosed by monocytes, M(naïve) and M(IFNγ) macrophages in a dose-dependent manner. They also induced NF-κB activation and increased TNFα, IL-8, and IL-1ß cytokine secretion. P. gingivalis OMVs were also found to induce anti-inflammatory IL-10 secretion. Although unprimed monocytes and macrophages were resistant to OMV-induced cell death, lipopolysaccharide or OMV priming resulted in a significantly reduced cell viability. P. gingivalis, T. denticola, and T. forsythia OMVs all activated inflammasome complexes, as monitored by IL-1ß secretion and ASC speck formation. ASC was critical for OMV-induced inflammasome formation, while AIM2-/- and Caspase-1-/- cells had significantly reduced inflammasome formation and NLRP3-/- cells exhibited a slight reduction. OMVs were also found to provide both priming and activation of the inflammasome complex. High-resolution microscopy and flow cytometry showed that P. gingivalis OMVs primed and activated macrophage inflammasomes in vivo with 80% of macrophages exhibiting inflammasome complex formation. In conclusion, periodontal pathogen OMVs were found to have significant immunomodulatory effects upon monocytes and macrophages and should therefore influence pro-inflammatory host responses associated with disease.

Differential Responses of Pattern Recognition Receptors to Outer Membrane Vesicles of Three Periodontal Pathogens.

Highly purified outer membrane vesicles (OMVs) of the periodontal pathogens, Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia were produced using tangential flow ultrafiltration, ultracentrifugation and Optiprep density gradient separation. Cryo-TEM and light scattering showed OMVs to be single lipid-bilayers with modal diameters of 75 to 158 nm. Enumeration of OMVs by nanoparticle flow-cytometry at the same stage of late exponential culture indicated that P. gingivalis was the most prolific OMV producer. P. gingivalis OMVs induced strong TLR2 and TLR4-specific responses and moderate responses in TLR7, TLR8, TLR9, NOD1 and NOD2 expressing-HEK-Blue cells. Responses to T. forsythia OMVs were less than those of P. gingivalis and T. denticola OMVs induced only weak responses. Compositional analyses of OMVs from the three pathogens demonstrated differences in protein, fatty acids, lipopolysaccharide, peptidoglycan fragments and nucleic acids. Periodontal pathogen OMVs induced differential pattern recognition receptor responses that have implications for their role in chronic periodontitis.