Self-adjuvanting lipopeptide vaccines

Despite the important role of adjuvants for vaccine development, relatively few adjuvants have been successfully incorporated into vaccines intended for human administration. This is in part due to the high toxicity associated with many experimental adjuvants. This lack of choice effectively hinders the ability to produce vaccines against many diseases, or to improve current vaccine formulations. The conjugation of immunostimulatory lipids to peptide antigens, to produce self-adjuvanting lipopeptide vaccines, has been tested in human clinical trials. These systems appear to have a number of advantages over more traditional adjuvants (e. g. alum salts) including the capacity for these vaccines to be administered via mucosal routes (e. g. orally or nasally) instead of by injection, elicitation of antigen-specific cytotoxic T-lymphocytes and mucosal immunity, as well as little-to-no observed toxicity. Several lipopeptide vaccine systems have been described in the literature, ranging from the conjugation of single fatty acid chains, to the conjugation of more complex lipids and glycolipids onto peptide antigens. The following review provides an overview of the most studied lipopeptide vaccine systems rouped into the following categories: 1) bacterial lipopeptides, including tri-palmitoyl-S-glyceryl cysteine (Pam(3)Cys) and di-palmitoyl-S- glyceryl cysteine (Pam(2)Cys); 2) the lipid-core peptide (LCP) and multiple antigen lipophilic adjuvant carrier (MALAC) systems; 3) single-chain palmitoylated peptides; and 4) glycolipids (e. g. monophosphoryl lipid A). The review also discusses the potential mechanisms of action for lipopeptide and glycolipopeptide vaccines, as well as structure activity relationships, and provides examples of studies utilising each system

Mucosal immunization: Adjuvants and delivery systems

The mucosal administration of vaccines is an area currently receiving a high level of interest due to potential advantages offered by this technique. These advantages include the ability to administer vaccines without need for needles, thus improving patient compliance with vaccination schedules, and the capacity to induce immune responses capable of preventing infections at the site of acquisition. Despite these advantages a number of limitations exist which currently inhibit our ability to successfully develop new mucosal vaccines. As such, much research is currently focused on developing new adjuvants and delivery systems to overcome these difficulties. However, despite high levels of interest in this area, relatively few mucosal vaccine candidates have successfully progressed to human clinical trials. In the review that follows, we aim to provide the reader with an overview of the immune system with respect to induction of mucosal immune responses. Furthermore, the review provides an overview of a number of microbial (bacterial toxins, CpG DNA, cytokines/chemokines, live vectors, and virus like particles) and synthetic (microspheres, liposomes, and lipopeptides) strategies that have been investigated as adjuvants or delivery systems for mucosal vaccine development, with a focus on the delivery of vaccines via the oral route

Tracking the concept of sustainability in Australian tourism policy and planning documents

In the current climate of intense turbulence, tourism must transform to a more sustainable development platform. Yet it remains unclear how the concept of sustainability is embedded at different levels of government policy and planning, and how this has evolved over time. This paper identifies the concept of sustainability as it is articulated in 339 Australian tourism strategic planning and policy documents published between 2000 and 2011. The paper examines the extent to which the concept of sustainable tourism is evident in the discourse of Australian tourism strategic planning documents at the national, state, regional and local levels, as well as the balance of the discourse in relation to sustainability objectives. The results show that the frequency of occurrence of sustainability as a concept has slightly increased in strategies over the past decade. At the same time, there has been a shift in the conceptualisation of sustainability, with thinking evolving from nature-based, social and triple bottom line concepts toward a focus on climate change, responsibility, adaption and transformation