Evolution of Th2 responses : Characterization of IL-4/13 in sea bass (Dicentrarchus labrax L.) and studies of expression and biological activity

Acknowledgements This research was funded by the European Commission under the 7th Framework Programme for Research and Technological Development (FP7) of the European Union (Grant Agreement 311993 TARGETFISH). T.W. received funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland). MASTS is funded by the Scottish Funding Council (grant reference number HR09011) and contributing institutions.Peer reviewedPublisher PD

TLR1/2, TLR7, and TLR9 Signals Directly Activate Human Peripheral Blood Naive and Memory B Cell Subsets to Produce Cytokines, Chemokines, and Hematopoietic Growth Factors

Recently, it has been reported that using multiple signals, murine and human B cells secrete several cytokines with pro-inflammatory and immunoregulatory properties. We present the first comprehensive analysis of 24 cytokines, chemokines, and hematopoietic growth factors production by purified human peripheral blood B cells (CD19+), and naive (CD19+CD27-) and memory (CD19+CD27+) B cells in response to direct and exclusive signaling provided by toll-like receptor (TLR) ligands Pam3CSK (TLR1/TLR2), Imiquimod (TLR7), and GpG-ODN2006 (TLR9). All three TLR ligands stimulated B cells (CD19+) to produce cytokines IL-1α, IL-1β, IL-6, TNF-α, IL-13, and IL-10, and chemokines MIP-1α, MIP-1β, MCP-1, IP-10, and IL-8. However, GM-CSF and G-CSF production was predominantly induced by TLR2 agonist. Most cytokines/chemokines/hematopoietic growth factors were predominantly or exclusively produced by memory B cells, and in general, TLR2 signal was more powerful than signal provided viaTLR7 and TLR9. No significant secretion of eotaxin, IFN-α, IFN-γ, IL-2, IL-3, IL-4, IL-5, IL-7, IL-15, IL-17, IL-12p40, IL-12p70, and TNF-β (lymphotoxin) was observed. These data demonstrate that human B cells can be directly activated viaTLR1/TLR2, TLR7, and TLR9 to induce secretion of cytokines, chemokines, and hematopoietic growth factors and suggest a role of B cells in immune response against microbial pathogenesis and immune homeostasis

Inositol Hexakisphosphate-Induced Autoprocessing of Large Bacterial Protein Toxins

Large bacterial protein toxins autotranslocate functional effector domains to the eukaryotic cell cytosol, resulting in alterations to cellular functions that ultimately benefit the infecting pathogen. Among these toxins, the clostridial glucosylating toxins (CGTs) produced by Gram-positive bacteria and the multifunctional-autoprocessing RTX (MARTX) toxins of Gram-negative bacteria have distinct mechanisms for effector translocation, but a shared mechanism of post-translocation autoprocessing that releases these functional domains from the large holotoxins. These toxins carry an embedded cysteine protease domain (CPD) that is activated for autoprocessing by binding inositol hexakisphosphate (InsP6), a molecule found exclusively in eukaryotic cells. Thus, InsP6-induced autoprocessing represents a unique mechanism for toxin effector delivery specifically within the target cell. This review summarizes recent studies of the structural and molecular events for activation of autoprocessing for both CGT and MARTX toxins, demonstrating both similar and potentially distinct aspects of autoprocessing among the toxins that utilize this method of activation and effector delivery

A dual role for the N-terminal domain of the IL-3 receptor in cell signalling

The interleukin-3 (IL-3) receptor is a cell-surface heterodimer that links the haemopoietic, vascular and immune systems and is overexpressed in acute and chronic myeloid leukaemia progenitor cells. It belongs to the type I cytokine receptor family in which the α-subunits consist of two fibronectin III-like domains that bind cytokine, and a third, evolutionarily unrelated and topologically conserved, N-terminal domain (NTD) with unknown function. Here we show by crystallography that, while the NTD of IL3Rα is highly mobile in the presence of IL-3, it becomes surprisingly rigid in the presence of IL-3 K116W. Mutagenesis, biochemical and functional studies show that the NTD of IL3Rα regulates IL-3 binding and signalling and reveal an unexpected role in preventing spontaneous receptor dimerisation. Our work identifies a dual role for the NTD in this cytokine receptor family, protecting against inappropriate signalling and dynamically regulating cytokine receptor binding and function.Sophie E. Broughton, Timothy R. Hercus, Tracy L. Nero, Winnie L. Kan ... Timothy P. Hughes, Angel F. Lopez ... et al

A splicing mutation affecting expression of ataxia-telangiectasia and Rad3-related protein (ATR) results in Seckel syndrome

Seckel syndrome (OMIM 210600) is an autosomal recessive disorder characterized by intrauterine growth retardation, dwarfism, microcephaly and mental retardation. Clinically, Seckel syndrome shares features in common with disorders involving impaired DNA-damage responses, such as Nijmegen breakage syndrome (OMIM 251260) and LIG4 syndrome (OMIM 606593). We previously mapped a locus associated with Seckel syndrome to chromosome 3q22.1–q24 in two consanguineous Pakistani families1. Further marker analysis in the families, including a recently born unaffected child with a recombination in the critical region, narrowed the region to an interval of 5 Mbp between markers D3S1316 and D3S1557 (145.29 Mbp and 150.37 Mbp). The gene encoding ataxia–telangiectasia and Rad3–related protein (ATR) maps to this region2,3. A fibroblast cell line derived from an affected individual displays a defective DNA damage response caused by impaired ATR function. We identified a synonymous mutation in affected individuals that alters ATR splicing. The mutation confers a phenotype including marked microcephaly (head circumference 12 s.d. below the mean) and dwarfism (5 s.d. below the mean). Our analysis shows that UV-induced ATR activation can occur in non-replicating cells following processing by nucleotide excision repair

An IL13Rα2 peptide exhibits therapeutic activity against metastatic colorectal cancer

36 p.-6 fig.BACKGROUND:Interleukin 13 receptor α2 (IL13Rα2) is overexpressed in metastatic colorectal cancer. Here, we have developed novel strategies to block IL-13 binding to IL13Rα2 in order to reduce metastatic spread.METHODS:Synthetic IL13Rα2 D1 peptide (GSETWKTIITKN) was tested for the inhibition of IL-13 binding to IL13Rα2 using ELISA and different cellular assays. Peptide blocking effects on different cell signalling mediators were determined by western blot. An enantiomer version of the peptide (D-D1) was prepared to avoid proteolytic digestion. Nude mice were used for tumour growth and survival analysis after treatment with IL13Rα2 peptides.RESULTS:IL13Rα2 D1 peptide inhibited migration, invasion, and proliferation in metastatic colorectal and glioblastoma cancer cells treated with IL-13. Residues 82K, 83T, 85I and 86T were essential for blocking IL-13. IL13Rα2 peptide abolished ligand-mediated receptor internalisation and degradation, and substantially decreased IL-13 signalling capacity through IL13Rα2 to activate the FAK, PI3K/AKT and Src pathways as well as MT1-MMP expression. In addition, D1 significantly inhibited IL-13-mediated STAT6 activation through IL13Rα1. Nude mice treated with the enantiomer D-D1 peptide showed a remarkable survival increase.CONCLUSIONS:We propose that the D-D1 peptide from IL13Rα2 represents a promising therapeutic agent to inhibit metastatic progression in colorectal cancer and, likely, other solid tumours.This research was supported by grants BIO2015-66489-R from the MINECO, Foundation Ramón Areces and PRB2 (IPT13/0001-ISCIII-SGEFI/FEDER).Peer reviewe