Cell Biology Commons^™

Constitutive Interferon Signaling Maintains Critical Threshold Of Mlkl Expression To License Necroptosis, Joseph Sarhan, Beiyun C. Liu, Hayley I. Muendlein, Chi G. Weindel, Irina Smirnova, Amy Y. Tang, Vladimir Ilyukha, Maxim Sorokin, Anton Buzdin, Katherine A. Fitzgerald, Alexander Poltorak

Katherine A. Fitzgerald

Interferons (IFNs) are critical determinants in immune-competence and autoimmunity, and are endogenously regulated by a low-level constitutive feedback loop. However, little is known about the functions and origins of constitutive IFN. Recently, lipopolysaccharide (LPS)-induced IFN was implicated as a driver of necroptosis, a necrotic form of cell death downstream of receptor-interacting protein (RIP) kinase activation and executed by mixed lineage kinase like-domain (MLKL) protein. We found that the pre-established IFN status of the cell, instead of LPS-induced IFN, is critical for the early initiation of necroptosis in macrophages. This pre-established IFN signature stems from cytosolic DNA sensing via cGAS/STING, and …

A Lipopolysaccharide-Induced Dna-Binding Protein For A Class Ii Gene In B Cells Is Distinct From Nf-Kappa B, Ellen M. Gravallese, Mark R. Boothby, Cynthia M. Smas, Laurie H. Glimcher

Ellen M. Gravallese

Class II (Ia) major histocompatibility complex molecules are cell surface proteins normally expressed by a limited subset of cells of the immune system. These molecules regulate the activation of T cells and are required for the presentation of antigens and the initiation of immune responses. The expression of Ia in B cells is determined by both the developmental stage of the B cell and by certain external stimuli. It has been demonstrated previously that treatment of B cells with lipopolysaccharide (LPS) results in increased surface expression of Ia protein. However, we have confirmed that LPS treatment results in a significant …

Tattletales And T-Bow Update 20141018, George Mcnamara

George McNamara

Tattletales and T-Bow Update 20141018

http://works.bepress.com/gmcnamara/63

Tattletales is my concept to multiplex fluorescent protein biosensors ("Tattletales", which is also the overall concept name) and multicolor FP reporters ("T-Bow" for Rainbow T-cells and tumor cells) to study the physiology of live cells.

These are based on:

1. LacI-GFP :: LacO operator synthetic tandem repeat array (Robinett et al 1996 JCB, Fig 4A, http://jcb.rupress.org/content/135/6/1685.full.pdf )

2. the plethora of fluorescent protein biosensors - see page 1 of this "63" download site.

3. the many colors, and combinations of colors (CY11.5, CyPet-YPet 90% FRET, simple color combination fusions, Steven Vogel's "V6" and "V8" …

Tattletales And T-Bow Update 20140602mon, George Mcnamara

George McNamara

Tattletales and T-Bow Update 20140602Mon

http://works.bepress.com/gmcnamara/42

Please see also http://works.bepress.com/gmcnamara/26

Tattletales: multiplex fluorescent protein biosensors by spatial localization with TALE-FPs, Cas9-FPs, ZF-FPs, LacI-FPs, TetR-FPs, etc.

T-Bow: Rainbow T-cells and Tumor cells (and ES cells, iPS cells, other cells and organisms). You can think of this as "Brainbow meets TALENs/Cas9/ZFNs/other DNA sequence specific binding proteins".

If not familiar with Brainbow, see

http://en.wikipedia.org/wiki/Brainbow

If not familiar with TALENs, Cas9, etc, see

http://www.addgene.org/genome_engineering/

Big idea: localizing fluorescent proteins - and/or Nano-Lanterns (Take Nagai) - to tandem repeat arrays - is a great way to improve signal to noise ratio compared to the usual …

Stomatin-Like Protein 2 Deficiency In T Cells Is Associated With Altered Mitochondrial Respiration And Defective Cd4+ T Cell Responses., Darah A Christie, Panagiotis Mitsopoulos, Julianna Blagih, Stanley D Dunn, Julie St-Pierre, Russell G Jones, Grant M Hatch, Joaquín Madrenas

Stanley D Dunn

Stomatin-like protein 2 (SLP-2) is a mostly mitochondrial protein that regulates mitochondrial biogenesis and function and modulates T cell activation. To determine the mechanism of action of SLP-2, we generated T cell-specific SLP-2-deficient mice. These mice had normal numbers of thymocytes and T cells in the periphery. However, conventional SLP-2-deficient T cells had a posttranscriptional defect in IL-2 production in response to TCR ligation, and this translated into reduced CD4(+) T cell responses. SLP-2 deficiency was associated with impaired cardiolipin compartmentalization in mitochondrial membranes, decreased levels of the NADH dehydrogenase (ubiquinone) iron-sulfur protein 3, NADH dehydrogenase (ubiquinone) 1β subcomplex subunit …

Splenic Endothelial Cell Lines Support Development Of Dendritic Cells From Bone Marrow, Geneviève Despars, Helen O'Neill

Helen O'Neill

Although growth factors are commonly used to generate dendritic cells (DCs) in vitro, the role of the microenvironment necessary for DC development is still poorly understood. The mixed splenic stromal cell population STX3 defines an in vitro microenvironment supportive of DC development. Dissection of cellular components of the STX3 stroma should provide information about a niche for DC development. STX3 was therefore cloned by single-cell sorting, and a panel of 102 splenic stromal cell lines was established. Four representative splenic stromal cell lines that support hematopoiesis from bone marrow are described here in terms of stromal cell type and DC …

Cell Surface Expression Of A Peptide Encoded By The Unrearranged Tcr-Vβ8.2 Gene, Janice Abbey, Mark Hulett, Helen O'Neill

Helen O'Neill

Germline transcription of T-cell receptor (TCR) genes has been described in early lymphoid cells. The most common explanation for this phenomenon is that transcription of unrearranged Vβ genes directs gene usage during the rearrangement event. Germline transcription of the TCR-Vβ8.2 gene has been detected in a precursor T-cell line, C1-V13D, which shows no rearrangement at any of the TCR gene loci. This cell line also shows weak binding of specific anti-V 8.2 antibody to the cell surface, consistent with expression of a truncated TCR chain. RT-PCR has been used to confirm expression of spliced germline transcripts of TCR-Vβ8.2 in C1-V13D …

The Immunogenicity Of Dendritic Cell-Derived Exosomes, Ben Quah, Helen O'Neill

Helen O'Neill

Exosome production represents an alternate endocytic pathway for secretion. Multivesicular endosomes (MVE) fuse with the plasma membrane expelling internal vesicles or exosomes from cells. Exosome production has been recently described for immune cells including B cells, dendritic cells (DC), mast cells, macrophages and T cells. Exosomes derived from some DC populations stimulate T lymphocyte proliferation in vitro and have potent capacity to generate anti-tumour immune responses in vivo. These reported studies have involved in vitro grown mature DC expanded from precursors with cytokines. However, immature DC produce higher numbers of exosomes than mature DC and this is thought to be …