HIV infection of dendritic cells subverts the IFN induction pathway via IRF-1 and inhibits type 1 IFN production

Many viruses have developed mechanisms to evade the IFN response. Here, HIV-1 was shown to induce a distinct subset of IFN-stimulated genes (ISGs) in monocyte-derived dendritic cells (DCs), without detectable type I or II IFN. These ISGs all contained an IFN regulatory factor 1 (IRF-1) binding site in their promoters, and their expression was shown to be driven by IRF-1, indicating this subset was induced directly by viral infection by IRF-1. IRF-1 and -7 protein expression was enriched in HIV p24 antigen-positive DCs. A HIV deletion mutant with the IRF-1 binding site deleted from the long terminal repeat showed reduced growth kinetics. Early and persistent induction of IRF-1 was coupled with sequential transient up-regulation of its 2 inhibitors, IRF-8, followed by IRF-2, suggesting a mechanism for IFN inhibition. HIV-1 mutants with Vpr deleted induced IFN, showing that Vpr is inhibitory. However, HIV IFN inhibition was mediated by failure of IRF-3 activation rather than by its degradation, as in T cells. In contrast, herpes simplex virus type 2 markedly induced IFNβ and a broader range of ISGs to higher levels, supporting the hypothesis that HIV-1 specifically manipulates the induction of IFN and ISGs to enhance its noncytopathic replication in DCs.

Alteration of the proline at position 7 of the HIV-1 spacer peptide p1 suppresses viral infectivity in a strain dependent manner

The HIV-1 spacer peptide p1 is located in the C-terminus of the Gag polyprotein and separates the nucleocapsid (NC) and p6(Gag). Research centered on p1 has been limited and as yet no function has been ascribed to this spacer peptide. We have previously found that the conserved p1 proline residues (position 7 and 13) are critical for replication in the HIV-1 strain HXB2-BH10. In this study we have focused on the proline rich p1-p6(Gag) C-terminus of HIV-1. We individually examined the role of p1 proline's in multiple strains of HIV-1 and investigated the role of three proline residues in p6(Gag) (P24, P25 and P30). Assessment of the HXB2-BH10 based mutants revealed that Gag-Pol incorporation relative to Gag decreased in the p1 mutant virions, with the double proline mutant the most impaired. Mutating both p1 proline residues was found to abolish infectivity in multiple strains of HIV-1. Independent mutation of the p1 proline at position 7 resulted in a strain-dependent suppression of viral infectivity. This defect correlates with the presence of a tyrosine residue at position 9 of p1 and occurs in the early phase of the HIV-1 replication cycle. The p1 proline residues were found to be functionally distinct from P24, P25 and P30 in p6(Gag). This work affords novel insights into our understanding of the role of p1 in HIV-1 replication.

The packaging and maturation of the HIV-1 Pol proteins

The Pol protein of human immunodeficiency virus type 1 (HIV-1) harbours the viral enzymes critical for viral replication; protease (PR), reverse transcriptase (RT), and integrase (IN). PR, RT and IN are not functional in their monomeric forms and must come together as either dimers (PR), heterodimers (RT) or tetramers (IN) to be catalytically active. Our knowledge of the tertiary structures of the functional enzymes is well advanced, and substantial progress has recently been made towards understanding the precise steps leading from Pol protein synthesis through viral assembly to the release of active viral enzymes. This review will summarise our current understanding of how the Pol proteins, which are initially expressed as a Gag-Pol fusion product, are packaged into the assembling virion and discuss the maturation process that results in the release of the viral enzymes in their active forms. Our discussion will focus on the relationship between structure and function for each of the viral enzymes. This review will also provide an overview of the current status of inhibitors against the HIV-1 Pol proteins. Effective inhibitors of PR and RT are well established and we will discuss the next generation inhibitors of these enzymes as well recent investigations that have highlighted the potential of IN and RNase H as antiretroviral targets.

Granulocyte-macrophage colony-stimulating factor augments phagocytosis of mycobacterium avium complex by human immunodeficiency virus type 1-infected monocytes/macrophages in vitro and in vivo

The role of human immunodeficiency virus type 1 (HIV-1) infection on the ability of human monocytes/macrophages to phagocytose Mycobacterium avium complex (MAC) in vivo and in vitro and the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on this function were investigated. By use of a flow cytometric assay to quantify phagocytosis, HIV-1 infection was found to impair the ability of monocyte-derived macrophages to phagocytose MAC in vitro, whereas GM-CSF significantly improved this defect. Phagocytosis was not altered by exposure to a mutant form of GM-CSF (E21R) binding only to the α chain of the GM-CSF receptor, suggesting that signaling by GM-CSF that leads to augmentation of phagocytosis is via the β chain of the receptor. In a patient with AIDS and disseminated multidrug-resistant MAC infection, GM-CSF treatment improved phagocytosis of MAC by peripheral blood monocytes and reduced bacteremia. These results imply that GM-CSF therapy may be useful in restoring antimycobacterial function by human monocytes/macrophages.

Proline residues within spacer peptide p1 are important for human immunodeficiency virus type 1 infectivity, protein processing, and genomic RNA dimer stability

The full-length human immunodeficiency virus type 1 (HIV-1) mRNA encodes two precursor polyproteins, Gag and GagProPol. An infrequent ribosomal frameshifting event allows these proteins to be synthesized from the same mRNA in a predetermined ratio of 20 Gag proteins for each GagProPol. The RNA frameshift signal consists of a slippery sequence and a hairpin stem-loop whose thermodynamic stability has been shown in in vitro translation systems to be critical to frameshifting efficiency. In this study we examined the frameshift region of HIV-1, investigating the effects of altering stem-loop stability in the context of the complete viral genome and assessing the role of the Gag spacer peptide p1 and the GagProPol transframe (TF) protein that are encoded in this region. By creating a series of frameshift region mutants that systematically altered the stability of the frameshift stem-loop and the protein sequences of the p1 spacer peptide and TF protein, we have demonstrated the importance of stem-loop thermodynamic stability in frameshifting efficiency and viral infectivity. Multiple changes to the amino acid sequence of p1 resulted in altered protein processing, reduced genomic RNA dimer stability, and abolished viral infectivity. The role of the two highly conserved proline residues in p1 (position 7 and 13) was also investigated. Replacement of the two proline residues by leucines resulted in mutants with altered protein processing and reduced genomic RNA dimer stability that were also noninfectious. The unique ability of proline to confer conformational constraints on a peptide suggests that the correct folding of p1 may be important for viral function.

The A-rich RNA sequences of HIV-1 pol are important for the synthesis of viral cDNA

The bias of A-rich codons in HIV-1 pol is thought to be a record of hypermutations in viral genomes that lack biological functions. Bioinformatic analysis predicted that A-rich sequences are generally associated with minimal local RNA structures. Using codon modifications to reduce the amount of A-rich sequences within HIV-1 genomes, we have reduced the flexibility of RNA sequences in pol to analyze the functional significance of these A-rich ‘structurally poor’ RNA elements in HIV-1 pol. Our data showed that codon modification of HIV-1 sequences led to a suppression of virus infectivity by 5–100-fold, and this defect does not correlate with, viral entry, viral protein expression levels, viral protein profiles or virion packaging of genomic RNA. Codon modification of HIV-1 pol correlated with an enhanced dimer stability of the viral RNA genome, which was associated with a reduction of viral cDNA synthesis both during HIV-1 infection and in a cell free reverse transcription assay. Our data provided direct evidence that the HIV-1 A-rich pol sequence is not merely an evolutionary artifact of enzyme-induced hypermutations, and that HIV-1 has adapted to rely on A-rich RNA sequences to support the synthesis of viral cDNA during reverse transcription, highlighting the utility of using ‘structurally poor’ RNA domains in regulating biological process.

Contemporary planning education and Indigenous cultural competency agendas : erasing terra nullius, respect and responsibility

As noted in Universities Australia’s (2011a, 2011b) investigations into Indigenous Cultural Competency, most universities have struggled with successfully devising and achieving a translation of Indigenous protocols into their curricula. Walliss & Grant (2000: 65) have also concluded that, given the nature of the built environment disciplines, including planning, and their professional practice activities, there is a “need for specific cultural awareness education” to service these disciplines and not just attempts to insert Indigenous perspectives into their curricula. Bradley’s policy initiative at the University of South Australia (1997-2007), “has not achieved its goal of incorporation of Indigenous perspectives into all its undergraduate programs by 2010, it has achieved an incorporation rate of 61%” (Universities Australia 2011a: 9; http://www.unisa.edu.au/ducier/icup/default.asp).

Contextually, Bradley’s strategic educational aim at University of South Australia led a social reformist agenda, which has been continued in Universities Australia’s release of Indigenous Cultural Competency (2011a; 2011b) reports that has attracted mixed media criticism (Trounson 2012a: 5, 2012b: 5) and concerns that it represents “social engineering” rather than enhancing “criticism as a pedagogical tool ... as a means of advancing knowledge” (Melleuish 2012: 10). While the Planning Institute of Australia’s (PIA) Indigenous Planning Policy Working Party has observed that fundamental changes are needed to the way Australian planning education addresses Indigenous perspectives and interests, it has concluded that planners “! perceptual limitations of their own discipline and the particular discourse of our own craft” were hindering enhanced learning outcomes (Wensing 2007: 2). Gurran (PIA 2007) has noted that the core curriculum in planning includes an expectation of “knowledge of ! Indigenous Australian cultures, including relationships between their physical environment and associated social and economic systems” but that it has not been addressed. This paper critiques these discourses and offers an Indigenous perspective of the debate.

Coastal planning, education and the Australian context

The Victorian Planning Minister’s response to the ‘Coastal Climate Change Advisor Report’, initiated by the Baillieu government in 2010, identified the need to “initiate ! a skills audit with the view to developing a range of professional development courses to meet the shortfall of professionals with the capability to assess coastal climate change impacts” (Victoria 2012). The following paper addresses this deficiency by examining how Australia’s higher education and further education sectors currently attend to the issue of coastal planning.

A detailed review of a large number of national and international planning programs was undertaken to highlight the subject matter contained in each program with a specific focus on any coastal planning courses. Working from a theoretical perspective, the first part of the paper addresses why a dedicated subject on Coastal Planning is required in the present Australian planning school syllabus, and how such a program would be positioned within the intent of PIA’s Education Policy.

Utilising the benefits of Problem Based learning and Student Centred Learning in relating to delivering a Coastal planning course, the second part of the paper provides a theoretical overview of the types of competencies which students may be expected to attain when undertaking such a course. The third part of the paper proposes a series of 12 lectures to underpin a unit titled “Coastal Planning: The Australian Context” which includes a draft lecture relating to the monitoring of Coastal Erosion in Adelaide.

Planning research and educational partnerships with Indigenous communities : practice, realities and lessons

Increasingly planning practice and research are having to engage with Indigenous communities in Australia to empower and position their knowledge in planning strategies and arguments. But also to act as articulators of their cultural knowledge, landscape aspirations and responsibilities and the need to ensure that they are directly consulted in projects that impact upon their ‘country’ generally and specifically. This need has changed rapidly over the last 25 years because of land title claim legal precedents, state and Commonwealth legislative changes, and policy shifts to address reconciliation and the consequences of the fore-going precedents and enactments. While planning instruments and their policies have shifted, as well as research grant expectations and obligations, many of these Western protocols do not recognise and sympathetically deal with the cultural and practical realities of Indigenous community management dynamics, consultation practices and procedures, and cultural events much of which are placing considerable strain upon communities who do not have the human and financial resources to manage, respond, co-operate and inform in the same manner expected of non-Indigenous communities in Australia. This paper reviews several planning formal research, contract research and educational engagements and case studies between the authors and various Indigenous communities, and highlights key issues, myths and flaws in the way Western planning and research expectations are imposed upon Indigenous communities that often thwart the quality and uncertainty of planning outcomes for which the clients, research agencies, and government entities were seeking to create.

What's 'childless' got to do with it?

Childlessness is increasing in Australia and has resulted in an upsurge of media commentary on the lives of childless women, This paper investigates the use of the label 'childless' in the Australian print media by drawing meaning and understanding from these representations within the context of pronatalist ideologies. Our analysis suggests that childless(ness) is used as an irrelevant descriptor and as a discreditable attribute, which fudher serves to perpetuate negative othering stereotypes of childless women. This is particularly exemplified through the representation of Australia's Prime Minister Julia Gillard by the print media. This analysis highlights the continued positioning of women in regards to their reproductive status.

Interconnectedness, multiplexity and the global student : the role of blogging and micro blogging in opening students horizons

The authors explore the world of blogging and micro blogging (twitter) as a means of mediating engagement with students, lawyers, academics and other interested and interesting people around the world. Through the use of auto-ethnographic case studies of their own experiences with blogging and micro blogging tools, the authors propose that far from being a distraction from student learning, these tools have the potential to open up an international professional collaborative space beyond the physical classroom, for both academics and our students, from their first year experience through to practical legal training and continuing professional development.