Functional Analysis of the Leading Malaria Vaccine Candidate AMA-1 Reveals an Essential Role for the Cytoplasmic Domain in the Invasion Process

A key process in the lifecycle of the malaria parasite Plasmodium falciparum is the fast invasion of human erythrocytes. Entry into the host cell requires the apical membrane antigen 1 (AMA-1), a type I transmembrane protein located in the micronemes of the merozoite. Although AMA-1 is evolving into the leading blood-stage malaria vaccine candidate, its precise role in invasion is still unclear. We investigate AMA-1 function using live video microscopy in the absence and presence of an AMA-1 inhibitory peptide. This data reveals a crucial function of AMA-1 during the primary contact period upstream of the entry process at around the time of moving junction formation. We generate a Plasmodium falciparum cell line that expresses a functional GFP-tagged AMA-1. This allows the visualization of the dynamics of AMA-1 in live parasites. We functionally validate the ectopically expressed AMA-1 by establishing a complementation assay based on strain-specific inhibition. This method provides the basis for the functional analysis of essential genes that are refractory to any genetic manipulation. Using the complementation assay, we show that the cytoplasmic domain of AMA-1 is not required for correct trafficking and surface translocation but is essential for AMA-1 function. Although this function can be mimicked by the highly conserved cytoplasmic domains of P. vivax and P. berghei, the exchange with the heterologous domain of the microneme protein EBA-175 or the rhoptry protein Rh2b leads to a loss of function. We identify several residues in the cytoplasmic tail that are essential for AMA-1 function. We validate this data using additional transgenic parasite lines expressing AMA-1 mutants with TY1 epitopes. We show that the cytoplasmic domain of AMA-1 is phosphorylated. Mutational analysis suggests an important role for the phosphorylation in the invasion process, which might translate into novel therapeutic strategies

The Role of Sialyl Glycan Recognition in Host Tissue Tropism of the Avian Parasite Eimeria tenella

Eimeria spp. are a highly successful group of intracellular protozoan parasites that develop within intestinal epithelial cells of poultry, causing coccidiosis. As a result of resistance against anticoccidial drugs and the expense of manufacturing live vaccines, it is necessary to understand the relationship between Eimeria and its host more deeply, with a view to developing recombinant vaccines. Eimeria possesses a family of microneme lectins (MICs) that contain microneme adhesive repeat regions (MARR). We show that the major MARR protein from Eimeria tenella, EtMIC3, is deployed at the parasite-host interface during the early stages of invasion. EtMIC3 consists of seven tandem MAR1-type domains, which possess a high specificity for sialylated glycans as shown by cell-based assays and carbohydrate microarray analyses. The restricted tissue staining pattern observed for EtMIC3 in the chicken caecal epithelium indicates that EtMIC3 contributes to guiding the parasite to the site of invasion in the chicken gut. The microarray analyses also reveal a lack of recognition of glycan sequences terminating in the N-glycolyl form of sialic acid by EtMIC3. Thus the parasite is well adapted to the avian host which lacks N-glycolyl neuraminic acid. We provide new structural insight into the MAR1 family of domains and reveal the atomic resolution basis for the sialic acid-based carbohydrate recognition. Finally, a preliminary chicken immunization trial provides evidence that recombinant EtMIC3 protein and EtMIC3 DNA are effective vaccine candidates

An EGF-like Protein Forms a Complex with PfRh5 and Is Required for Invasion of Human Erythrocytes by Plasmodium falciparum

Invasion of erythrocytes by Plasmodium falciparum involves a complex cascade of protein-protein interactions between parasite ligands and host receptors. The reticulocyte binding-like homologue (PfRh) protein family is involved in binding to and initiating entry of the invasive merozoite into erythrocytes. An important member of this family is PfRh5. Using ion-exchange chromatography, immunoprecipitation and mass spectroscopy, we have identified a novel cysteine-rich protein we have called P. falciparum Rh5 interacting protein (PfRipr) (PFC1045c), which forms a complex with PfRh5 in merozoites. Mature PfRipr has a molecular weight of 123 kDa with 10 epidermal growth factor-like domains and 87 cysteine residues distributed along the protein. In mature schizont stages this protein is processed into two polypeptides that associate and form a complex with PfRh5. The PfRipr protein localises to the apical end of the merozoites in micronemes whilst PfRh5 is contained within rhoptries and both are released during invasion when they form a complex that is shed into the culture supernatant. Antibodies to PfRipr1 potently inhibit merozoite attachment and invasion into human red blood cells consistent with this complex playing an essential role in this process

Instagraff:The Influence of Web 2.0, Social Media, and User-Created Content Upon Graffiti Culture Performed in Cyber/Space.

Instagraff, graffiti found on the social media website Instagram, examines social and technological advances that have prompted graffiti culture to appear ‘mainstream’. Recognising the birth of Web 2.0 as a key turning point, this study analyses images from social media accounts of graffiti writers, relating them to the works of Goffman (1959), Burgess (2007), and Baudrillard (1970). Its findings suggest that online representations of graffiti culture are no longer necessarily based upon sensory, deviant, risk-taking associated with urban graffiti. The use of social media by young would-be graffiti writers has created new avenues for the commercialisation of a vibrant, but deviant, subculture. Therefore, graffiti shared on social media cannot be considered a true representation of graffiti subculture, but a procession of simulacra, developing new forms of graffiti culture dislocated from graffiti’s deviant origins

Event Management and MICE: ISE case study

Conferència a càrrec de Mr. Mike Blackman, managing director ISE-Integrated Systems Europe, sobre les àrees clau de l'esdeveniment, concretament, en la promoció, relació amb agents clau, visitants i convidats, mitjans i mètriques per analitzar l'impacte de l'esdeveniment. La conferència s'emmarca dins de l'assignatura 'Turisme de Negocis i Esdeveniments' de 3r/4rt curs del Grau en Turisme, impartida pel Sr. Pol Fage

Comrades! Lives of Australian Communists

This collection of biographies of 100 Australian communists celebrates a century of the Communist Party of Australia (CPA). The CPA started small, on 30 October 1920, but its members' dedication and the course of world events made it a national, even international, force. They worked on the wharves, building sites, railways" in factories, mines, shops and hospitals. Others were novelists, playwrights, filmmakers, singers and lawyers. Many were union officials" one was Australia's only Communist Member of Parliament. Some were seared by World War, Depression, or the Cold War. Others were propelled by the social movements of the sixties and seventies. What drew them together was their opposition to the global dominance of capitalism, their desire for industrial and social justice, and the impulse to escape religious orthodoxy and class and gender privilege.Communists dared to think about a world without war, without divisions of race and class" of a society based on cooperation and shared wealth, and an economy run for the people. They believed that ordinary people, working together, could change the world.The CPA was the first party to oppose the White Australia policy, to stand up against fascism, and to fight for Aboriginal rights. Its members imposed the world's first Green Bans, and they helped build hundreds of social movement organizations though which people fought to have their say in the country's future. The books, plays, films and songs created by its members helped create a uniquely Australian culture. Many were subjected to surveillance and repression by Australian political police, discrimination at work, and constant public attacks. Few were ever acknowledged in history books or the media. To mark the centenary of the Communist Party of Australia, the SEARCH Foundation, in association with the Australian Society for the Study of Labour History, is compiling short biographies of Australian communists. This selection of 100 will be supplemented by many more on the SEARCH website (www.search.org.au

The accessibility of public spaces for people with dementia: A new priority for the 'open city'

The social model of disability de-medicalises disability and politicises it as an issue of universal rights. However, the rights of people with dementia have been less strongly advocated than those of people with physical disabilities. This is particularly the case with environmental planning and design. The needs of people with dementia are now informing the design of residential homes and day centres, but the issue of accessibility to public spaces and amenities has been almost completely neglected. Many outdoor environments such as shopping centres or parks may be inhospitable for people with dementia because they are disorientating, difficult to interpret and navigate, threatening or distressing. The article reviews the literature on indoor design for dementia, reports on research investigating the accessibility of outdoor environments, and describes a new approach using virtual reality technology to enable people with dementia to identify and test outdoor design and planning improvements themselves

Making the outside world dementia-friendly: design issues and considerations

Design guidelines for dementia care homes have, in recent years, acknowledged the important role the internal environment plays in influencing the functional capabilities and emotional well-being of people with dementia. However, although the majority of people with dementia live in the community, similar guidance does not exist in relation to the outdoor environment. To identify aspects of design that should be considered in making the outside world dementia-friendly an analysis of the literature on the needs of older people with dementia and on current knowledge of best practice for internal environments was carried out. By drawing parallels with the outside environment this paper demonstrates that design solutions do potentially exist which would enable older people with dementia to continue to negotiate and use their local neighbourhoods. Familiarity, legibility, distinctiveness, accessibility, comfort, and safety all appear to have a major influence. Small street blocks with direct, connected routes and good visual access, varied urban form, and architectural features, and distinctive, unambiguous environmental cues could enhance successful orientation and wayfinding. Services and facilities within walking distance with adequate seating, lighting, shelter, and well-maintained, smooth, level, plain paving would ameliorate attending problems of physical frailty. The authors are now empirically testing these initial findings.