Invasive pneumococcal disease in Australia, 2011 and 2012.

In Australia, there were 1,883 cases (8.3 per 100,000 population) of invasive pneumococcal disease (IPD) notified to the National Notifiable Diseases Surveillance System (NNDSS) in 2011 and 1,823 cases (8.0 per 100,000) in 2012. The overall rate of IPD in Indigenous Australians was 9 times the rate of IPD in non-Indigenous Australians in 2011 and 7 times in 2012. Following the July 2011 introduction of the 13-valent pneumococcal conjugate vaccine (13vPCV) to the National Immunisation Program, rates of IPD in children aged less than 5 years decreased from 19.5 per 100,000 in 2011 to 12.6 per 100,000 in 2012. In Indigenous adults aged 50 years or over the rates of IPD caused by serotypes included in the 23-valent pneumococcal polysaccharide vaccine (23vPPV) continued to increase in both 2011 (47.2 per 100,000) and 2012 (51.2 per 100,000). The rates of IPD in non-Indigenous adults aged 65 years or over caused by serotypes included in the 23vPPV also increased in 2011 (10.1 per 100,000) and 2012 (11.2 per 100,000). There were 134 deaths attributable to IPD in 2011 and 126 in 2012, although it should be noted that deaths may be under-reported. The number of invasive pneumococcal isolates with reduced penicillin susceptibility remained low and reduced susceptibility to ceftriaxone/cefotaxime continued to be rare.

Bortezomib Improves Adoptive T-cell Therapy by Sensitizing Cancer Cells to FasL Cytotoxicity.

Cancer immunotherapy shows great promise but many patients fail to show objective responses, including in cancers that can respond well, such as melanoma and renal adenocarcinoma. The proteasome inhibitor bortezomib sensitizes solid tumors to apoptosis in response to TNF-family death ligands. Because T cells provide multiple death ligands at the tumor site, we investigated the effects of bortezomib on T-cell responses in immunotherapy models involving low-avidity antigens. Bortezomib did not affect lymphocyte or tissue-resident CD11c(+)CD8(+) dendritic cell counts in tumor-bearing mice, did not inhibit dendritic cell expression of costimulatory molecules, and did not decrease MHC class I/II-associated antigen presentation to cognate T cells. Rather, bortezomib activated NF-κB p65 in CD8(+) T cells, stabilizing expression of T-cell receptor CD3ζ and IL2 receptor-α, while maintaining IFNγ secretion to improve FasL-mediated tumor lysis. Notably, bortezomib increased tumor cell surface expression of Fas in mice as well as human melanoma tissue from a responsive patient. In renal tumor-bearing immunodeficient Rag2(-/-) mice, bortezomib treatment after adoptive T-cell immunotherapy reduced lung metastases and enhanced host survival. Our findings highlight the potential of proteasome inhibitors to enhance antitumor T-cell function in the context of cancer immunotherapy.

Invasive pneumococcal disease in Australia, 2009 and 2010.

Enhanced surveillance for invasive pneumococcal disease (IPD) was conducted in all Australian states and territories in 2009 and 2010 with comprehensive comparative data available since 2002. There were 1,556 cases of IPD notified to the National Notifiable Diseases Surveillance System in Australia in 2009, a notification rate of 7.2 cases per 100,000 population. In 2010 there were 1,640 cases, a notification rate of 7.4 cases per 100,000. The overall rate of IPD in Indigenous Australians was almost 6 times the rate in non-Indigenous Australians in both 2009 and 2010. In 2009 and 2010, notification rates of IPD caused by serotypes included in the 7-valent pneumococcal conjugate vaccine (7vPCV) continued to decrease across all age groups. Rates of IPD caused by non-7vPCV serotypes continued to show an increasing trend in both Indigenous and non-Indigenous children aged less than 5 years. In Indigenous adults (≥50 years), rates of IPD caused by both 23-valent pneumococcal polysaccharide vaccine (23vPPV) serotypes and non-23vPPV serotypes continued to show an overall increase, particularly in 2010. There were 110 deaths attributed to IPD in 2009 and 137 in 2010, although it should be noted that deaths may be under-reported. The number of invasive pneumococcal isolates with reduced penicillin susceptibility remained low and reduced susceptibility to third generation cephalosporins was rare.

A 1536-well quantitative high-throughput screen to identify compounds targeting cancer stem cells.

Tumor cell subpopulations called cancer stem cells (CSCs) or tumor-initiating cells (TICs) have self-renewal potential and are thought to drive metastasis and tumor formation. Data suggest that these cells are resistant to current chemotherapy and radiation therapy treatments, leading to cancer recurrence. Therefore, finding new drugs and/or drug combinations that cause death of both the differentiated tumor cells as well as CSC populations is a critical unmet medical need. Here, we describe how cancer-derived CSCs are generated from cancer cell lines using stem cell growth media and nonadherent conditions in quantities that enable high-throughput screening (HTS). A cell growth assay in a 1536-well microplate format was developed with these CSCs and used to screen a focused collection of oncology drugs and clinical candidates to find compounds that are cytotoxic against these highly aggressive cells. A hit selection process that included potency and efficacy measurements during the primary screen allowed us to efficiently identify compounds with potent cytotoxic effects against spheroid-derived CSCs. Overall, this research demonstrates one of the first miniaturized HTS assays using CSCs. The procedures described here should enable further testing of the effect of compounds on CSCs and help determine which pathways need to be targeted to kill them.

Coactivation of AKT and ß-catenin in mice rapidly induces formation of lipogenic liver tumors.

Obesity is a risk factor for development of certain cancers but the basis for this risk is unclear. In this study, we developed a novel mouse model that demonstrates directly how lipogenic phenotypes commonly associated with diet-induced metabolic syndromes can influence hepatic cancer development. Activated AKT and ß-catenin (AKT/CAT) genes were hydrodynamically codelivered using the Sleeping Beauty transposon to initiate liver tumorigenesis. AKT/CAT and MET/CAT combination induced microscopic tumor foci by 4 weeks, whereas no tumorigenesis resulted from delivery of AKT, MET, or CAT alone. Primary AKT/CAT tumor cells were steatotic (fatty) hepatocellular adenomas which progressed to hepatocellular carcinomas (HCC) upon in vivo passage, whereas primary MET/CAT tumors emerged directly as frank HCC. Conversion of AKT/CAT tumor cells to frank HCC during passage was associated with induction of the human HCC marker α-fetoprotein and the stem cell marker CD133. Using hierarchical clustering and gene set enrichment analysis, we compared the primary murine AKT/CAT and MET/CAT tumors to a panel of 53 human HCCs and determined that these two mouse models could be stratified as distinct subtypes associated in humans with poor clinical prognosis. The chief molecular networks identified in primary and passaged AKT/CAT tumors were steatosis and lipid metabolic pathways, respectively. Our findings show how coactivation of the AKT and CAT pathways in hepatocytes can efficiently model development of a lipogenic tumor phenotype. Furthermore, we believe that our approach could speed the dissection of microenvironmental factors responsible for driving steatotic-neoplastic transformation to frank carcinoma, through genetic modification of existing immunodefined transgenic models.

Antigen-specific CD8 T cells can eliminate antigen-bearing keratinocytes with clonogenic potential via an IFN-gamma-dependent mechanism.

The immune system surveys the skin for keratinocytes (KCs) infected by viruses or with acquired genetic damage. The mechanism by which T cells mediate KC elimination is however undefined. In this study we show that antigen-specific CD8 T cells can eliminate antigen-bearing KCs in vivo and inhibit their clonogenic potential in vitro, independently of the effector molecules perforin and Fas-ligand (Fas-L). In contrast, IFN-gamma receptor expression on KCs and T cells producing IFN-gamma are each necessary and sufficient for in vitro inhibition of KC clonogenic potential. Thus, antigen-specific cytotoxic T lymphocytes (CTLs) may mediate destruction of epithelium expressing non-self antigen by eliminating KCs with potential for self-renewal through an IFN-gamma-dependent mechanism.

TLR7 stimulation augments T effector-mediated rejection of skin expressing neo-self antigen in keratinocytes.

Immunotherapy generally fails to induce tumour regression in spontaneously arising tumours. Failure is attributed to both tumour-related factors and an ineffective immune response. As a model of tumour immunotherapy, without the confounding effects of potential tumour-determined mechanisms of immune evasion, we studied the requirements for rejection of skin grafts expressing a neo-self antigen in somatic cells and not in antigen-presenting cells. When antigen expression was restricted to somatic cells, both CD4(+) and CD8(+) effector cells were required for graft rejection. Although freshly placed grafts were spontaneously rejected, healed grafts established under the cover of T cell depletion were not rejected even after T cell numbers recovered to a level where freshly placed grafts on the same animal were rejected, suggesting that healed skin grafts expressing a neo-self antigen only in somatic cells could not be rejected by primed recipients with functional effector T cells. Local TLR7 ligation induced inflammatory responses and rejection of healed grafts exposed to the TLR agonist but did not induce rejection of untreated healed grafts on the same animal. Thus, local pro-inflammatory signalling via TLR7 can promote effector T cell function against skin cells displaying their nominal antigen.

Generalized substitution of isoencoding codons shortens the duration of papillomavirus L1 protein expression in transiently gene-transfected keratinocytes due to cell differentiation.

Recently we reported that gene codon composition determines differentiation-dependent expression of the PV L1 genes in mouse primary keratinocytes (KCs) in vitro and in vivo (Zhao et al. 2005, Mol. Cell Biol. 25:8643-8655). Here, we investigated whether generalized substitution of isoencoding codons affects the duration of expression of PV L1 genes in mouse and human KCs in day 1 culture transiently transfected with native (Nat) and codon modified (Mod) L1 genes. Following transient transfection, KC continuously transcribed both Nat and Mod PV L1 genes for at least 12 days, with the levels of L1 mRNAs from the Mod L1 genes significantly higher than those from the Nat L1 genes. However, continuous L1 protein expression at day 9 post-transfection was observed for both mouse and human KCs transfected with the Nat L1 genes only. Further, aa-tRNAs prepared from D8 KC cultures enhanced translation of two PV Nat L1 DNAs in RRL lysate and PV Nat L1 mRNAs in D0 cell-free lysate, whereas aa-tRNAs from D0 KCs enhanced translation of PV Mod L1 mRNAs in D8 cell-free lysate. It appears that aa-tRNAs in less-differentiated and differentiated KCs differentially match the PV Nat and Mod L1 mRNAs to regulate their translations in vitro.