Granzyme A induces caspase-independent mitochondrial damage, a required first step for apoptosis.
AuthorsMartinvalet D, Zhu P, Lieberman J
JournalImmunity
PubMed ID15780992
'Granzyme A (GzmA) triggers cell death with apoptotic features by targeting the endoplasmic reticulum-associated SET complex, which contains the GzmA-activated DNase NM23-H1, its inhibitor SET, and Ape1. The SET complex was postulated to translocate to the nucleus in response to oxidative stress and participate in its repair. Because mitochondrial damage ... More
Microenvironmental contaminations induced by fluorescent lipophilic dyes used for noninvasive in vitro and in vivo cell tracking.
AuthorsLassailly F, Griessinger E, Bonnet D,
JournalBlood
PubMed ID20215639
'Determining how normal and leukemic stem cells behave in vivo, in a dynamic and noninvasive way, remains a major challenge. Most optical tracking technologies rely on the use of fluorescent or bioluminescent reporter genes, which need to be stably expressed in the cells of interest. Because gene transfer in primary ... More
Interleukin-7-dependent expansion and persistence of melanoma-specific T cells in lymphodepleted mice lead to tumor regression and editing.
AuthorsWang LX, Li R, Yang G, Lim M, O'Hara A, Chu Y, Fox BA, Restifo NP, Urba WJ, Hu HM
JournalCancer Res
PubMed ID16288050
'Active-specific immunotherapy with dendritic cells loaded with peptide derived from the melanoma antigen, gp100, failed to mediate regression of established B16F10 melanoma in normal mice. Dendritic cell vaccination induced activation and subsequent deletion of adoptively transferred naive CD8+ T-cell receptor transgenic (pmel-1) T cells specific for gp100 in normal mice. ... More
High-throughput flow cytometry to detect selective inhibitors of ABCB1, ABCC1, and ABCG2 transporters.
'Up-regulation of pump (transporter) expression and selection of resistant cancer cells result in cancer multidrug resistance to diverse substrates of these transporters. While more than 48 members of the ATP binding cassette (ABC) transporter superfamily have been identified, up to now only three human ABC transporters-ABCB1, ABCC1, and ABCG2-have unambiguously ... More
Editing antigen presentation: antigen transfer between human B lymphocytes and macrophages mediated by class A scavenger receptors.
AuthorsHarvey BP, Quan TE, Rudenga BJ, Roman RM, Craft J, Mamula MJ,
JournalJ Immunol
PubMed ID18768860
'B lymphocytes can function independently as efficient APCs. However, our previous studies demonstrate that both dendritic cells and macrophages are necessary to propagate immune responses initiated by B cell APCs. This finding led us to identify a process in mice whereby Ag-specific B cells transfer Ag to other APCs. In ... More
Multiplexed labeling of viable cells for high-throughput analysis of glycine receptor function using flow cytometry.
AuthorsGilbert DF, Wilson JC, Nink V, Lynch JW, Osborne GW,
JournalCytometry A
PubMed ID19184990
Flow cytometry is an important drug discovery tool because it permits high-content multiparameter analysis of individual cells. A new method dramatically enhanced screening throughput by multiplexing many discrete fixed cell populations; however, this method is not suited to assays requiring functional cellular responses. HEK293 cells were transfected with unique mutant ... More
A flow cytometry-based assay to assess minute frequencies of CD8+ T cells by their cytolytic function.
AuthorsStanke J, Hoffmann C, Erben U, von Keyserling H, Stevanovic S, Cichon G, Schneider A, Kaufmann AM,
JournalJ Immunol Methods
PubMed ID20558172
Limited sample size and low sensitivity of currently used functional assays challenge direct analysis of cytotoxic CD8+ T lymphocyte activity to quantify antigen-specific immunity after infection or vaccination. Our flow cytometry-based assay reproducibly detects at least three epitope-specific CD8+ T lymphocytes by their cytolytic function. As exemplified for viral epitopes ... More
Transcriptional profiling of antigen-dependent murine B cell differentiation and memory formation.
AuthorsBhattacharya D, Cheah MT, Franco CB, Hosen N, Pin CL, Sha WC, Weissman IL,
JournalJ Immunol
PubMed ID17982071
Humoral immunity is characterized by the generation of Ab-secreting plasma cells and memory B cells that can more rapidly generate specific Abs upon Ag exposure than their naive counterparts. To determine the intrinsic differences that distinguish naive and memory B cells and to identify pathways that allow germinal center B ... More
The role of endothelial cells in the retinal stem and progenitor cell niche within a 3D engineered hydrogel matrix.
AuthorsAizawa Y, Shoichet MS
JournalBiomaterials
PubMed ID22560669
Cell-cell interactions are critical to understanding functional tissues. A number of stem cell populations have been shown to receive key regulatory information from endothelial cells (ECs); however, the role of ECs in the retinal stem and progenitor cell (RSPC) niche has been largely unexplored. To gain greater insight into the ... More
Perforin triggers a plasma membrane-repair response that facilitates CTL induction of apoptosis.
Perforin delivers granzymes to induce target-cell apoptosis. At high concentrations, perforin multimerizes in the plasma membrane to form pores. However, whether granzymes enter target cells via membrane pores is uncertain. Here we find that perforin at physiologically relevant concentrations and during cell-mediated lysis creates pores in the target-cell membrane, transiently ... More
Quantum dot/peptide-MHC biosensors reveal strong CD8-dependent cooperation between self and viral antigens that augment the T cell response.
AuthorsAnikeeva N, Lebedeva T, Clapp AR, Goldman ER, Dustin ML, Mattoussi H, Sykulev Y
JournalProc Natl Acad Sci U S A
PubMed ID17077145
Cytotoxic T lymphocytes (CTL) can respond to a few viral peptide-MHC-I (pMHC-I) complexes among a myriad of virus-unrelated endogenous self pMHC-I complexes displayed on virus-infected cells. To elucidate the molecular recognition events on live CTL, we have utilized a self-assembled biosensor composed of semiconductor nanocrystals, quantum dots, carrying a controlled ... More
Identification of pathways regulating cell size and cell-cycle progression by RNAi.
AuthorsBjörklund M, Taipale M, Varjosalo M, Saharinen J, Lahdenperä J, Taipale J
JournalNature
PubMed ID16496002
Many high-throughput loss-of-function analyses of the eukaryotic cell cycle have relied on the unicellular yeast species Saccharomyces cerevisiae and Schizosaccharomyces pombe. In multicellular organisms, however, additional control mechanisms regulate the cell cycle to specify the size of the organism and its constituent organs. To identify such genes, here we analysed ... More
Rapid conversion of effector mechanisms from NK to T cells during virus-induced lysis of allogeneic implants in vivo.
AuthorsBrehm MA, Daniels KA, Ortaldo JR, Welsh RM
JournalJ Immunol
PubMed ID15905505
Viral infections can strongly stimulate both NK cell and allospecific CD8 T cell responses, and these same effector cells can lyse allogeneic cell lines in vitro. However, the impact of viral infections on the effector systems mediating rejection of allogeneic tissues in vivo has not been fully explored. Using in ... More
Cytolytic cells induce HMGB1 release from melanoma cell lines.
AuthorsIto N, DeMarco RA, Mailliard RB, Han J, Rabinowich H, Kalinski P, Stolz DB, Zeh HJ, Lotze MT
JournalJ Leukoc Biol
PubMed ID16968820
High mobility group box 1 (HMGB1) is one of the recently defined damage-associated molecular pattern molecules, passively released from necrotic cells and secreted by activated macrophage/monocytes. Whether cytolytic cells induce HMGB1 release from tumor cells is not known. We developed a highly sensitive method for detecting intracellular HMGB1 in tumor ... More