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Mount Isa, Australia

Broughton S.E.,St. Vincents Institute | Hercus T.R.,The Center for Cancer Biology | Lopez A.F.,The Center for Cancer Biology | Parker M.W.,St. Vincents Institute | Parker M.W.,University of Melbourne
Current Opinion in Structural Biology | Year: 2012

Cytokines are well recognized for the pleiotropic nature of their signaling and biological activities on many cell types and their role in health and disease. Recent years have seen a steady stream of new cytokine receptor crystal structures including those that are activated by GM-CSF, type I interferon, and a variety of interleukins. Highlights include the observation of a dodecameric signaling complex for the GM-CSF receptor, electron microscopy imaging of an intact gp130/IL-6/IL-6Rα ternary receptor complex bound to its signal transducing Janus kinase and visualization of novel cytokine recognition mechanisms in the interleukin-17 and type I interferon families. This increasing knowledge in cytokine structural biology is driving new opportunities for developing novel therapies to modulate cytokine function in a diverse range of diseases including malignancies and chronic inflammation. © 2012 Elsevier Ltd.

Wang X.,University of Tartu | Wang X.,Shaanxi University of Chinese Medicine | Laan M.,University of Tartu | Bichele R.,University of Tartu | And 4 more authors.
Frontiers in Immunology | Year: 2012

The autoimmune regulator (Aire)-directed ectopic expression of tissue-specific antigens (TSAs) by mature medullary thymic epithelial cells (mTECs) has been viewed as an essen-tial mechanism in the induction of central tolerance. Recent data suggest that the survival of mTECs extends beyond the Aire+ cell population to form the post-Aire mTEC popula-tion and Hassall's corpuscles (HCs). The nature and function of these post-Aire epithelial cells and structures, however, have remained unidentified. In this study, we characterized in detail the end-stage development of mTECs and HCs in both Aire-sufficient and Aire-deficient mice. In addition, using a transgenic mouse model in which the LacZ reporter gene is under the control of the endogenous Aire promoter, we purified and analyzed the post-Aire mTECs to characterize their function. We showed that the end-stage maturation of mTECs closely resembles that of keratinocytes and that the lack of Aire results in a marked block of mTEC differentiation, which is partially overcome by ligands for RANK and CD40. We also provide evidence that, during mTEC development, Aire is expressed only once and during a limited 1-2 day period. The following loss of Aire expression is accompanied by a quick downregulation of MHC class II and CD80, and of most of the Aire-dependent and Aire-independent TSAs, with the exception of keratinocyte-specific genes. In the final stage of maturation, the mTECs lose their nuclei to become HCs and specifically express desmogleins (DGs) 1 and 3, which, via cross-presentation by APCs, may contribute to tolerance against these pemphigus vulgaris-related TSAs. © 2012 Wang, Laan, Bichele, Kisand, Scott and Peterson.

Lee E.M.,University of New South Wales | Yee D.,University of New South Wales | Busfield S.J.,CSL Ltd | McManus J.F.,Monash University | And 9 more authors.
Haematologica | Year: 2015

The prognosis of older patients with acute myelogenous leukemia is generally poor. The interleukin-3 receptor α- chain (CD123) is highly expressed on the surface of acute leukemia cells compared with normal hematopoietic stem cells. CSL362 is a fully humanized, CD123-neutralizing monoclonal antibody containing a modified Fc structure, which enhances human natural killer cell antibody-dependent cell-mediated cytotoxicity. Six continuous acute myelogenous leukemia xenografts established from patient explants and characterized by cell and molecular criteria, produced progressively lethal disease 42-202 days after transplantation. CSL362 alone reduced engraftment of one of four and three of four acute myelogenous leukemia xenografts in the bone marrow and peripheral organs, respectively. A cytarabine and daunorubicin regimen was optimized using this model to identify potentially synergistic interactions with CSL362. Cytarabine/daunorubicin improved the survival of mice engrafted with four of four acute myelogenous leukemia xenografts by 31-41 days. Moreover, CSL362 extended the survival of cytarabine/daunorubicin-treated mice for two of two acute myelogenous leukemia xenografts, while augmentation of natural killer cell-deficient NSG mice with adoptively transferred human natural killer cells improved survival against a single xenograft. Interestingly, this enhanced CSL362 efficacy was lost in the absence of chemotherapy. This study shows that acute myelogenous leukemia xenografts provide a platform for the evaluation of new therapeutics, simulating complex in vivo interactions, and that the in vivo efficacy of CSL362 supports continued clinical development of this drug. © 2015 Ferrata Stor ti Foundation.

Hercus T.R.,The Center for Cancer Biology | Dhagat U.,St. Vincents Institute | Kan W.L.T.,The Center for Cancer Biology | Broughton S.E.,St. Vincents Institute | And 11 more authors.
Cytokine and Growth Factor Reviews | Year: 2013

The GM-CSF, IL-3 and IL-5 family of cytokines, also known as the βc family due to their receptors sharing the signalling subunit βc, regulates multiple biological processes such as native and adaptive immunity, inflammation, normal and malignant hemopoieis, and autoimmunity. Australian scientists played a major role in the discovery and biological characterisation of the βc cytokines and their recent work is revealing unique features of cytokine receptor assembly and signalling. Furthermore, specific antibodies have been generated to modulate their function. Characterisation of the structural and dynamic requirements for the activation of the βc receptor family and the molecular definition of downstream signalling pathways are providing new insights into cytokine receptor signalling as well as new therapeutic opportunities. © 2013.

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