Identification of Leishmania Proteins Preferentially Released in Infected Cells Using Change Mediated Antigen Technology (CMAT)

Although Leishmania parasites have been shown to modulate their host cell's responses to multiple stimuli, there is limited evidence that parasite molecules are released into infected cells. In this study, we present an implementation of the change mediated antigen technology (CMAT) to identify parasite molecules that are preferentially expressed in infected cells. Sera from mice immunized with cell lysates prepared from L. donovani or L. pifanoi-infected macrophages were adsorbed with lysates of axenically grown amastigotes of L. donovani or L. pifanoi, respectively, as well as uninfected macrophages. The sera were then used to screen inducible parasite expression libraries constructed with genomic DNA. Eleven clones from the L. pifanoi and the L. donovani screen were selected to evaluate the characteristics of the molecules identified by this approach. The CMAT screen identified genes whose homologs encode molecules with unknown function as well as genes that had previously been shown to be preferentially expressed in the amastigote form of the parasite. In addition a variant of Tryparedoxin peroxidase that is preferentially expressed within infected cells was identified. Antisera that were then raised to recombinant products of the clones were used to validate that the endogenous molecules are preferentially expressed in infected cells. Evaluation of the distribution of the endogenous molecules in infected cells showed that some of these molecules are secreted into parasitophorous vacuoles (PVs) and that they then traffic out of PVs in vesicles with distinct morphologies. This study is a proof of concept study that the CMAT approach can be applied to identify putative Leishmania parasite effectors molecules that are preferentially expressed in infected cells. In addition we provide evidence that Leishmania molecules traffic out of the PV into the host cell cytosol and nucleus

The role of place branding and image in the development of sectoral clusters: the case of Dubai

This paper contextualizes how place branding and image influence the development of Dubai’s key sectoral clusters, including the key determinants of growth and success under the impression of Porter’s cluster theory. The approach is exploratory and of a qualitative inductive nature. Data was collected through conducting 21 semi-structured interviews with Dubai’s marketing/communication managers and stakeholders. Findings suggest that Dubai’s traditional clusters, namely, trading, tourism and logistics that have strong place branding and image show strong signs of success owing to Dubai’s geographical location (i.e., physical conditions). Among the new clusters, the financial sector is also benefitting from place branding. The results suggest that the success of traditional clusters have a positive spill over effect on the new clusters, in particular on construction and real estate. For policy makers it is worth to note that the recent success of the financial services cluster in Dubai will have positive impact on both, the traditional as well new clusters. The marketing and brand communication managers must consider the correlation and interplay of strength of activities amongst trading, tourism and logistics clusters and its implication while undertaking place branding for clients in their sector