Publications by authors named "Tania Crough"

Background: The inter-jurisdictional National Mutual Acceptance (NMA) scheme for Human Research Ethics Committee (HREC) approvals of human research is designed to reduce the reported delays and costs of ethical review. Introduction of the NMA set forth an uncoupling of the ethics and governance review processes, permitting a single ethical review for multiple sites, while continuing separate governance review for each centre covering financial and operational aspects of the research project.

Aim: To compare the time required to gain ethics and governance approvals in Australia for a non-interventional investigator-led study from December 2015 to approval times for an earlier pre-NMA study utilising a similar study design and study sites and evaluate the effect that the NMA has had on total approval time for non-interventional multi-centre projects.

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Glioblastoma multiforme (GBM) is one of the most aggressive human brain malignancies. Even with optimal treatment, median survival is less than 6 months for patients with recurrent GBM. Immune-based therapies have the potential to improve patient outcome by supplementing standard treatment.

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The reconstitution of anti-viral cellular immunity following hematopoietic stem cell transplantation (HSCT) is crucial in preventing cytomegalovirus (CMV)-associated complications. Thus immunological monitoring has emerged as an important tool to better target pre-emptive anti-viral therapies. However, traditional laboratory-based assays are too cumbersome and complicated to implement in a clinical setting.

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The frequent detection of human cytomegalovirus (CMV) antigens in glioblastoma multiforme (GBM) has raised the possibility of exploiting CMV-specific T-cell immunotherapy to control this disease in CMV--seropositive patients. Here, we have conducted a comprehensive ex vivo profiling of CMV-specific CD8(+) T-cell responses in a cohort of GBM patients. Of the patients analyzed, approximately half exhibited serological evidence of past infection with CMV.

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Primary infection or recrudescence of latent virus infection in transplant recipients can be manifested either as asymptomatic or symptomatic disease. Here we show that symptomatic human cytomegalovirus (HCMV) or Epstein-Barr virus (EBV) infection or recrudescence following solid organ transplantation (SOT) was coincident with a dramatic skewing of T-cell receptor beta variable (TRBV) repertoire, with expansions of monoclonal/oligoclonal clonotypes. As the clinical symptoms resolved, the peripheral blood repertoire reverted to a more diverse distribution.

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Activation of the nuclear factor-kappaB pathway by Epstein-Barr virus-encoded latent membrane protein-1 (LMP-1) leads to an up-regulation of the major histocompatibility complex class I antigen-processing pathway. Paradoxically, LMP-1 itself induces a subdominant CD8+ T-cell response and appears to have evolved to avoid immune recognition. Here we show that, although expression of LMP-1 in human cells dramatically enhanced the trans-presentation of CD8+ T-cell epitopes, cis-presentation of LMP-1-derived epitopes was severely impaired.

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Following primary infection, human cytomegalovirus (HCMV) establishes lifelong latency and periodically reactivates without causing symptoms in healthy individuals. In the absence of an adequate host-derived immune response, this fine balance of permitting viral reactivation without causing pathogenesis is disrupted, and HCMV can subsequently cause invasive disease and an array of damaging indirect immunological effects. Over the last decade, our knowledge of the immune response to HCMV infection in healthy virus carriers and diseased individuals has allowed us to translate these findings to develop better diagnostic tools and therapeutic strategies.

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Using ex vivo antigen-specific T-cell analysis, we found that symptomatic cytomegalovirus recrudescence in transplant recipients was coincident with reduced expression of gamma interferon (IFN-gamma) by virus-specific CD8(+) T cells and an up-regulation of CD38 expression on these T cells, although there was no significant change in the absolute number of virus-specific cells (as assessed by major histocompatibility complex-peptide multimers). In contrast, HLA class I-matched transplant patients with asymptomatic viral recrudescence showed increased expansion of antigen-specific T cells and highly stable IFN-gamma expression by epitope-specific T cells. These studies suggest that a strong functional T-cell response plays a crucial role in defining the clinical outcome of acute viral recrudescence.

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Stem cell transplantation (SCT) remains the most effective curative therapy for the majority of hematopoietic malignancies. Unfortunately, SCT is limited by its toxicity and infectious complications that result from profound immunosuppression. In particular, acquisition of exogenous or reactivation of endogenous human cytomegalovirus (HCMV) is common after SCT.

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The classical paradigm for T cell dynamics suggests that the resolution of a primary acute virus infection is followed by the generation of a long-lived pool of memory T cells that is thought to be highly stable. Very limited alteration in this repertoire is expected until the immune system is re-challenged by reactivation of latent viruses or by cross-reactive pathogens. Contradicting this view, we show here that the T cell repertoire specific for two different latent herpes viruses in the peripheral blood displayed significant contemporaneous co-fluctuations of virus-specific CD8(+) T cells.

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Despite more than a 10-fold increase in T cell numbers in G-CSF-mobilized peripheral blood stem cell (PBSC) grafts, incidence and severity of acute graft-vs-host disease (GVHD) are comparable to bone marrow transplantation. As CD1d-restricted, Valpha24+Vbeta11+ NKT cells have pivotal immune regulatory functions and may influence GVHD, we aimed to determine whether G-CSF has any effects on human NKT cells. In this study, we examined the frequency and absolute numbers of peripheral blood NKT cells in healthy stem cell donors (n = 8) before and following G-CSF (filgrastim) treatment.

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Although the importance of CD4+ T cell responses to human cytomegalovirus (HCMV) has recently been recognized in transplant and immunosuppressed patients, the precise specificity and nature of this response has remained largely unresolved. In the present study we have isolated CD4+ CTL which recognize epitopes from HCMV glycoproteins gB and gH in association with two different HLA-DR antigens, DRA1*0101/DRB1*0701 (DR7) and DRA1*0101/DRB1*1101 (DR11). Comparison of amino acid sequences of HCMV isolates revealed that the gB and gH epitope sequences recognized by human CD4+ T cells were not only conserved in clinical isolates from HCMV but also in CMV isolates from higher primates (chimpanzee, rhesus and baboon).

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There are a number of observations that suggest the dsRNA-activated protein kinase, PKR, may play an active role in formation and maintenance of leukemia, including nonrandom chromosomal deletions in acute leukemia as well as truncations and deletions of the PKR gene in some leukemia cell lines. However, there is little direct evidence from patient material that this is so. Here we show that full-length PKR is present but not active in 21 of 28 patient samples from B-cell chronic lymphocytic leukemia (B-CLL).

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Human cytomegalovirus (HCMV) can establish both nonproductive (latent) and productive (lytic) infections. Many of the proteins expressed during these phases of infection could be expected to be targets of the immune response; however, much of our understanding of the CD8(+)-T-cell response to HCMV is mainly based on the pp65 antigen. Very little is known about T-cell control over other antigens expressed during the different stages of virus infection; this imbalance in our understanding undermines the importance of these antigens in several aspects of HCMV disease pathogenesis.

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The BCR-ABL fusion proteins, b2a2 and b3a2, are potential targets for a beneficial graft-versus-leukemia (GVL) effect after allogeneic stem cell transplantation for chronic myeloid leukemia (CML). This study demonstrates that CD4+ T cells specific to the b2a2 peptide can be generated from a normal allogeneic stem cell transplant donor after stimulation with monocyte-derived dendritic cells (Mo-DC) using culture conditions applicable to clinical use. Stimulation of donor T-cell enriched mononuclear cells (MNC) with b2a2-pulsed Mo-DC produced approximately 3 x 10(9) b2a2-specific CD4+ T cells.

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