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Artificial APC

Masaki Ito, Kazumi Hayashi, Tamiko Minamisawa, Sadamu Homma, Shigeo Koido, Kiyotaka Shiba
Adjuvants are indispensable for achieving a sufficient immune response from vaccinations. From a functional viewpoint, adjuvants are classified into two categories: "physical adjuvants" increase the efficacy of antigen presentation by antigen-presenting cells (APC) and "signal adjuvants" induce the maturation of APC. Our previous study has demonstrated that a physical adjuvant can be encrypted into proteinous antigens by creating artificial proteins from combinatorial assemblages of epitope peptides and those peptide sequences having propensities to form certain protein structures (motif programming)...
2017: PloS One
Nina Chi Sabins, Olesya Chornoguz, Karen Leander, Fred Kaplan, Richard Carter, Michelle Kinder, Kurtis Bachman, Raluca Verona, Shixue Shen, Vipul Bhargava, Sandra Santulli-Marotto
T cell expression of TIM-3 following Ag encounter has been associated with a continuum of functional states ranging from effector memory T cells to exhaustion. We have designed an in vitro culture system to specifically address the impact of anti-TIM-3/TIM-3 engagement on human Ag-specific CD8 T cells during a normal response to Ag and found that anti-TIM-3 treatment enhances T cell function. In our in vitro T cell culture system, MART1-specific CD8 T cells were expanded from healthy donors using artificial APCs...
November 10, 2017: Journal of Immunology: Official Journal of the American Association of Immunologists
Xiaoqi Sun, Xiao Han, Ligeng Xu, Min Gao, Jun Xu, Rong Yang, Zhuang Liu
The development of artificial antigen presenting cells (aAPCs) to mimic the functions of APCs such as dendritic cells (DCs) to stimulate T cells and induce antitumor immune responses has attracted substantial interests in cancer immunotherapy. In this work, a unique red blood cell (RBC)-based aAPC system is designed by engineering antigen peptide-loaded major histocompatibility complex-I and CD28 activation antibody on RBC surface, which are further tethered with interleukin-2 (IL2) as a proliferation and differentiation signal...
September 1, 2017: Small
Bing-Mae Chen, Mohammad Ameen Al-Aghbar, Chien-Hsin Lee, Tien-Ching Chang, Yu-Cheng Su, Ya-Chen Li, Shih-En Chang, Chin-Chuan Chen, Tsai-Hua Chung, Yuan-Chun Liao, Chau-Hwang Lee, Steve R Roffler
T lymphocytes are important mediators of adoptive immunity but the mechanism of T cell receptor (TCR) triggering remains uncertain. The interspatial distance between engaged T cells and antigen-presenting cells (APCs) is believed to be important for topological rearrangement of membrane tyrosine phosphatases and initiation of TCR signaling. We investigated the relationship between ligand topology and affinity by generating a series of artificial APCs that express membrane-tethered anti-CD3 scFv with different affinities (OKT3, BC3, and 2C11) in addition to recombinant class I and II pMHC molecules...
2017: Frontiers in Immunology
Kods Mahdhaoui, Benjamin Fournier, Mathieu A Derbanne
OBJECTIVES: Assessing the role of dentinal fluid proteins in trans-dentinal diffusion of free monomers in vitro. METHODS: An artificial pulp chamber (APC) topped human dentin disks was used. A simplified two-step etch-and-rinse adhesive was formulated with 2-hydroethyl-methacrylate (HEMA), Bisphenol-A-diglycidyl-methacrylate (BisGMA), using Camphorquinone/tertiary amine as initiators. Two extraction media were used: buffered saline (Control), buffered saline with 1% bovine serum albumin (BSA)...
April 29, 2017: Dental Materials: Official Publication of the Academy of Dental Materials
Jitka Danadova, Natalie Matijescukova, Anna Mac Gillavry Danylevska, Martin Anger
Optimal culture conditions are essential for successful IVM of mammalian oocytes and for their further development into an embryo. In the present study we used live cell imaging microscopy to assess the effects of suboptimal culture temperature on various aspects of IVM, including duration of meiosis I, dynamics of polar body extrusion, chromosome congression, anaphase-promoting complex/cyclosome (APC/C) activation and aneuploidy. The data showed that even a small deviation from the optimal incubation temperature causes marked changes in the duration and synchronicity of meiosis, APC/C activity and the frequency of chromosome congression and segregation errors...
April 2017: Reproduction, Fertility, and Development
Gerhard J Schütz, Johannes B Huppa
T-cell antigen recognition is remarkably efficient: when scanning the surface of antigen-presenting cells (APCs), T-cells can detect the presence of just a few single antigenic peptide/MHCs (pMHCs), which are often vastly outnumbered by structurally similar non-stimulatory endogenous pMHCs (Irvine et al., Nature 419(6909):845-849, 2002; Purbhoo et al., Nat Immunol 5(5):524-530, 2004; Huang et al., Immunity 39(5):846-857, 2013). How T-cells achieve this is still enigmatic, in particular in view of the rather moderate affinity that TCRs typically exert for antigenic pMHCs, at least when measured in vitro (Davis et al...
2017: Methods in Molecular Biology
Derfogail Delcassian, Susanne Sattler, Iain E Dunlop
Recent advances in biomaterials design offer the potential to actively control immune cell activation and behaviour. Many human diseases, such as infections, cancer, and autoimmune disorders, are partly mediated by inappropriate or insufficient activation of the immune system. T cells play a central role in the host immune response to these diseases, and so constitute a promising cell type for manipulation. In vivo, T cells are stimulated by antigen presenting cells (APC), therefore to design immunoengineering biomaterials that control T cell behaviour, artificial interfaces that mimic the natural APC-T cell interaction are required...
March 1, 2017: Integrative Biology: Quantitative Biosciences From Nano to Macro
Tatsunori Goto, Tetsuya Nishida, Erina Takagi, Kotaro Miyao, Daisuke Koyama, Reona Sakemura, Ryo Hanajiri, Keisuke Watanabe, Nobuhiko Imahashi, Seitaro Terakura, Makoto Murata, Hitoshi Kiyoi
Programmed death-ligand 1 (PD-L1) binds to programmed death-1 (PD-1) on activated T cells and contributes to T-cell exhaustion. PD-L1 expressed on antigen-presenting cells (APCs) could be thought to inhibit the induction of Ag-specific cytotoxic T lymphocytes (CTLs) by transducing negative signal into T cells; however, the roles of PD-L1 on APCs have not yet been well examined. Therefore, we evaluated the roles of PD-L1 on APCs in the induction of Ag-specific CTLs. CD3 T cells isolated from cytomegalovirus (CMV)-seropositive healthy donors were stimulated with mature dendritic cells pulsed with CMV pp65-derived HLA-restricted peptides in the presence of anti-PD-L1 blocking antibody...
October 2016: Journal of Immunotherapy
Alyssa L Siefert, Michael J Caplan, Tarek M Fahmy
Antigen-presenting cells (APCs) sense microorganisms via pathogen-associated molecular patterns (PAMPs) by both extra- and intracellular Toll-like Receptors (TLRs), initiating immune responses against invading pathogens. Bacterial PAMPs include extracellular lipopolysaccharides and intracellular unmethylated CpG-rich oligodeoxynucleotides (CpG). We hypothesized that a biomimetic approach involving antigen-loaded nanoparticles (NP) displaying Monophosphoryl Lipid A (MPLA) and encapsulating CpG may function as an effective "artificial bacterial" biomimetic vaccine platform...
August 2016: Biomaterials
Sarine Markossian, Alexei Arnaoutov, Nakhle S Saba, Vladimir Larionov, Mary Dasso
Most solid tumors are aneuploid, carrying an abnormal number of chromosomes, and they frequently missegregate whole chromosomes in a phenomenon termed chromosome instability (CIN). While CIN can be provoked through disruption of numerous mitotic pathways, it is not clear which of these mechanisms are most critical, or whether alternative mechanisms could also contribute significantly in vivo. One difficulty in determining the relative importance of candidate CIN regulators has been the lack of a straightforward, quantitative assay for CIN in live human cells: While gross mitotic abnormalities can be detected visually, moderate levels of CIN may not be obvious, and are thus problematic to measure...
July 2, 2016: Cell Cycle
Longhao Sun, Hao Guo, Ruoyu Jiang, Li Lu, Tong Liu, Zhixiang Zhang, Xianghui He
Professional antigen-presenting cells (APCs) are potent generators of tumor antigen-specific cytotoxic T lymphocytes (CTLs) for adoptive immunotherapy; however, generation of APCs is cumbersome, expensive, and subject to the tumor microenvironment. Artificial APCs (aAPCs) have been developed as a cost-effective alternative to APCs. We developed a cellular aAPC that efficiently generated alpha-fetoprotein (AFP)-specific CTLs. We genetically modified the human B cell lymphoma cell line BJAB with a lentiviral vector to establish an aAPC called BA15...
April 5, 2016: Oncotarget
Jitka Danadova, Natalie Matijescukova, Anna Mac Gillavry Danylevska, Martin Anger
Optimal culture conditions are essential for successful IVM of mammalian oocytes and for their further development into an embryo. In the present study we used live cell imaging microscopy to assess the effects of suboptimal culture temperature on various aspects of IVM, including duration of meiosis I, dynamics of polar body extrusion, chromosome congression, anaphase-promoting complex/cyclosome (APC/C) activation and aneuploidy. The data showed that even a small deviation from the optimal incubation temperature causes marked changes in the duration and synchronicity of meiosis, APC/C activity and the frequency of chromosome congression and segregation errors...
March 9, 2016: Reproduction, Fertility, and Development
Anthony Garnier, Mohamad Hamieh, Aurélie Drouet, Jérôme Leprince, Denis Vivien, Thierry Frébourg, Brigitte Le Mauff, Jean-Baptiste Latouche, Olivier Toutirais
Owing to their multiple immune functions, CD4(+) T cells are of major interest for immunotherapy in chronic viral infections and cancer, as well as for severe autoimmune diseases and transplantation. Therefore, standardized methods allowing rapid generation of a large number of CD4(+) T cells for adoptive immunotherapy are still awaited. We constructed stable artificial antigen-presenting cells (AAPCs) derived from mouse fibroblasts. They were genetically modified to express human leukocyte antigen (HLA)-DR molecules and the human accessory molecules B7...
August 2016: Immunology and Cell Biology
Anita Wnętrzak, Kazimierz Łątka, Katarzyna Makyła-Juzak, Joanna Zemla, Patrycja Dynarowicz-Łątka
Outer layer of cellular membrane contains ordered domains enriched in cholesterol and sphingolipids, called 'lipid rafts', which play various biological roles, i.e., are involved in the induction of cell death by apoptosis. Recent studies have shown that these domains may constitute binding sites for selected drugs. For example alkylphosphocholines (APCs), which are new-generation antitumor agents characterized by high selectivity and broad spectrum of activity, are known to have their molecular targets located at cellular membrane and their selective accumulation in tumor cells has been hypothesized to be linked with the alternation of biophysical properties of lipid rafts...
August 2015: Molecular Membrane Biology
Hyun-Woo Cho, Su-Yeon Kim, Dae-Hee Sohn, Min-Ji Lee, Mi-Young Park, Hyun-Jung Sohn, Hyun-Il Cho, Tai-Gyu Kim
Human γδ T cells play important roles in the regulation of infection and cancer. To understand the roles of costimulatory signals in activation and expansion ex vivo, Vγ9Vδ2 T cells were grown with artificial APCs that express CD83, 4-1BB ligand, and/or CD32, which allowed a loading of αCD3 and αCD28 antibodies. The costimulatory signals through CD80, 4-1BB, and CD83 ligand in low levels of IL-2 triggered an explosive ex vivo proliferation of Vγ9Vδ2 T cells capable of secreting high levels of IL-2, IFN-γ, and TNF-α...
April 2016: Journal of Leukocyte Biology
Markus Axmann, Gerhard J Schütz, Johannes B Huppa
T-cells are remarkably specific and effective when recognizing antigens in the form of peptides embedded in MHC molecules (pMHC) on the surface of Antigen Presenting Cells (APCs). This is despite T-cell antigen receptors (TCRs) exerting usually a moderate affinity (µM range) to antigen when binding is measured in vitro(1). In view of the molecular and cellular parameters contributing to T-cell antigen sensitivity, a microscopy-based methodology has been developed as a means to monitor TCR-pMHC binding in situ, as it occurs within the synapse of a live T-cell and an artificial and functionalized glass-supported planar lipid bilayer (SLB), which mimics the cell membrane of an Antigen presenting Cell (APC) (2)...
October 30, 2015: Journal of Visualized Experiments: JoVE
Alexander A Celik, Thomas Kraemer, Trevor Huyton, Rainer Blasczyk, Christina Bade-Döding
Human leukocyte antigen (HLA)-E molecules are potent inhibitors of NK cell-mediated killing. Low in polymorphisms, two alleles are widely expressed among diverse populations: HLA-E*01:01 and HLA-E*01:03. Both alleles are distinguished by one SNP resulting in the substitution Arg107Gly. Both alleles present a limited set of peptides derived from class I leader sequences physiologically; however, HLA-E*01:01 presents non-canonical peptides in the absence of HLA class I molecules. To further assess the functional differences between both alleles, we analyzed the peptide repertoire of HLA-E*01:03 by applying soluble HLA technology followed by mass-spectrometric peptide sequencing...
January 2016: Immunogenetics
S Davoodi, R F Cooke, A C C Fernandes, B I Cappellozza, J L M Vasconcelos, R L A Cerri
The aim of this study was to test the effect of expression of estrus at artificial insemination (AI) on endometrium, conceptus, and CL gene expression of beef cows. Thirty-six multiparous nonlactating Nelore cows were enrolled on an estradiol- and progesterone (P4)-based timed AI protocol (AI = Day 0) and then slaughtered for the endometrium, CL, and conceptus collection on Day 19. The animals were retrospectively grouped on the basis of cows that (1) showed signs of estrus near AI (n = 19; estrus) and (2) did not show any signs of estrus (n = 17; nonestrus)...
March 1, 2016: Theriogenology
Quan Wang, W E Moerner
Oligomerization plays a critical role in shaping the light-harvesting properties of many photosynthetic pigment-protein complexes, but a detailed understanding of this process at the level of individual pigments is still lacking. To study the effects of oligomerization, we designed a single-molecule approach to probe the photophysical properties of individual pigment sites as a function of protein assembly state. Our method, based on the principles of anti-Brownian electrokinetic trapping of single fluorescent proteins, step-wise photobleaching, and multiparameter spectroscopy, allows pigment-specific spectroscopic information on single multipigment antennae to be recorded in a nonperturbative aqueous environment with unprecedented detail...
November 10, 2015: Proceedings of the National Academy of Sciences of the United States of America
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