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Sample records for cytotoxic-t-lymphocyte memory induction

  1. Induction of TNP-specific cytotoxic T lymphocyte memory in vivo in the absence of T helper cell activity

    SciTech Connect

    Hurme, M.; Varkila, K.; Sihvola, M.

    1986-09-15

    The question of whether TH cells are required for the priming of CTL precursors (CTLp) in vivo was studied by using Txbm mice (Thymectomized, irradiated, and stem cell-reconstituted mice). In these mice, TNP-specific CTL could be induced in vitro with TNP-coupled spleen cells only if the cultures were supplemented with an IL 2-containing supernatant (ConAsup). In contrast to normal mice, TNP-specific Lyt-2-TH cells could not be induced by skin painting with trinitrochlorobenzene (TNCB) (as tested by the ability to help CTL formation from thymocyte or normal spleen precursors). These data confirm previous findings that Txbm mice possess CTLp but that their TH compartment is deficient. TNCB skin painting had, however, a clear priming effect on the CTLp population: spleen cells from TNCB-painted mice could give rise to specific CTL with a lower amount of ConAsup than spleen cells from unprimed mice. In addition to this, priming changed the CTLp so that stimulation with lightly coupled cells (0.1 mM trinitrobenzene sulfonic acid (TNBS) instead of 10 mM TNBS) became effective. These changes took place without a significant increase in the frequency of TNP-specific CTL precursors. The data obtained are consistent with the concept that at least with some antigens, CTLp proliferation (clonal expansion), which is probably caused by activated TH cells, is not required for the induction of immunologic memory in vivo.

  2. Activation of epitope-specific memory cytotoxic T lymphocyte responses by synthetic peptides.

    PubMed

    Reali, E; Guerrini, R; Giori, B; Borghi, M; Marastoni, M; Tomatis, R; Traniello, S; Masucci, M G; Gavioli, R

    1996-08-01

    Cytotoxic T lymphocytes (CTL) recognize antigens as short peptides selected for presentation by their ability to bind to MHC class I molecules. Polyclonal Epstein-Barr virus (EBV)-specific memory CTL responses, reactivated from blood lymphocytes of HLA-A11-positive individuals by stimulation with the autologous EBV-transformed lymphoblastoid cell line (LCL), are often dominated by reactivites directed to the peptide epitope IVTDFSVIK (IVT), corresponding to amino acids 416-424 of EBV nuclear antigen-4 (EBNA4). We now report the selective activation of IVT-specific CTL by stimulation of lymphocytes with the corresponding synthetic peptide. A more than 10-fold increase in frequency of CTL clones with this specificity (from 8% to 96%) was obtained when the peptide was presented by HLA-A11-transfected T2 cells (T2/A11). Titration of synthetic peptide in cytotoxic assay demonstrated that clones activated under these conditions are as efficient as clones activated by conventional LCL stimulations. Induction of memory CTL responses required low surface density of MHC: peptide complexes, since reactivation was achieved by stimulation with T2/A11 cells pulsed with concentrations of peptide that are suboptimal for induction of target cell lysis. This protocol of activation revealed the presence of IVT-specific CTL precursors in a donor that failed to mount an IVT-specific response upon stimulation with the autologous B95.8 virus-transformed LCL. The results suggest that stimulation with synthetic peptide epitopes can be efficiently used for induction of memory CTL responses, and may be particularly helpful for the selective expansion of subdominant CTL specificities.

  3. Cell-mediated immunity against herpes simplex induction of cytotoxic T lymphocytes.

    PubMed Central

    Lawman, M J; Rouse, B T; Courtney, R J; Walker, R D

    1980-01-01

    The conditions required for the induction of both primary cytotoxic T lymphocytes (CTL) in vivo and secondary CTL in vitro against herpes simplex virus type 1 (HSV-1)-infected cells were defined. Primary CTL responses occurred only in mice exposed to infectious HSV-1. These responses, which were shown to be mediated by T lymphocytes, peaked at 1 week and had disappeared by 2 weeks after infection. The level of primary cytotoxicity was enhanced by treatment of mice with cyclophosphamide before infection. Secondary in vitro CTL responses were more pronounced and were induced by some forms of inactivated virus as well as by infectious HSV-1. Thus, both ultraviolet light- and glutaraldehyde-inactivated preparations of HSV-1 induced CTL, but heat-inactivated and detergent-extracted antigens failed to do so. The reasons for the differing efficiency of infectious and noninfectious HSV-1 for induction of CTL are discussed. PMID:6244225

  4. A new theory of cytotoxic T-lymphocyte memory: implications for HIV treatment.

    PubMed Central

    Wodarz, D; Page, K M; Arnaout, R A; Thomsen, A R; Lifson, J D; Nowak, M A

    2000-01-01

    We use simple mathematical models to examine the dynamics of primary and secondary cytotoxic T-lymphocyte (CTL) responses to viral infections. In particular, we are interested in conditions required to resolve the infection and to protect the host upon secondary challenge. While protection against reinfection is only effective in a restricted set of circumstances, we find that resolution of the primary infection requires persistence of CTL precursors (GTLp), as well as a fast rate of activation of the CTLp. Since these are commonly the defining characteristics of CTL memory, we propose that CTL memory may have evolved in order to clear the virus during primary challenge. We show experimental data from lymphocytic choriomeningitis virus infection in mice, supporting our theory on CTL memory. We adapt our models to HIV and find that immune impairment during the primary phase of the infection may result in the failure to establish CTL memory which in turn leads to viral persistence. Based on our models we suggest conceptual treatment regimes which ensure establishment of CTL memory. This would allow the immune response to control HIV in the long term in the absence of continued therapy. PMID:10794051

  5. Reduction of otherwise remarkably stable virus-specific cytotoxic T lymphocyte memory by heterologous viral infections

    PubMed Central

    1996-01-01

    Experimental analyses of the acute cytotoxic T lymphocyte (CTL) response to viruses have focused on studying these infections in immunologically naive hosts. In the natural environment, however, viral CTL responses occur in hosts that are already immune to other infectious agents. To address which factors contribute to the maintenance and waning of immunological memory, the following study examined the frequencies of virus-specific CTL precursor cells (pCTL) not only using the usual experimental paradigm where mice undergo acute infections with a single virus, and in mice immune to a single virus, but also in immune mice after challenge with various heterologous viruses. As determined by limiting dilution assays, the pCTL frequency (p/f) per CD8+ T cell specific for lymphocytic choriomeningitis virus (LCMV), Pichinde virus (PV), or vaccinia virus (VV) increased during the acute infections, peaking at days 7-8 with frequencies as high as 1/27-1/74. Acute viral infections such as these elicit major expansions in the CD8+ T cell number, which has been reported to undergo apoptosis and decline after most of the viral antigen has been cleared. Although the decline in the total number of virus-specific pCTL after their peak in the acute infection was substantial, for all three viruses the virus- specific p/f per CD8+ T cell decreased only two- to fourfold and remained at these high levels with little fluctuation for well over a year. The ratios of the three immunodominant peptide-specific to total LCMV-specific clones remained unchanged between days 7 and 8 of acute infection and long-term memory, suggesting that the apoptotic events did not discriminate on the basis of T cell receptor specificity, but instead nonspecifically eliminated a large proportion of the activated T cells. However, when one to five heterologous viruses (LCMV, PV, VV, murine cytomegalovirus, and vesicular stomatitis virus) were sequentially introduced into this otherwise stable memory pool, the

  6. Induction of cytotoxic T lymphocytes against ovarian cancer-initiating cells.

    PubMed

    Weng, Desheng; Song, Baizheng; Durfee, John; Sugiyama, Valerie; Wu, Zhengrong; Koido, Shigeo; Calderwood, Stuart K; Gong, Jianlin

    2011-10-15

    The majority of patients with stage III/IV ovarian carcinoma that respond initially to standard therapies ultimately undergo relapse due to the survival of small populations of cells with tumor-initiating potential. These ovarian cancer (OVCA)-initiating cells (OCIC) are sometimes called cancer stem cells (CSC) because they express stem cell markers, and can survive conventional therapies such as chemotherapy, which usually target rapidly replicating tumor cells, and give rise to recurrent tumors that are more chemo-resistant and more aggressive. Thus, it would be desirable to develop a therapy that could selectively target OCIC and be used to complement the conventional therapies. In this study, we isolated a subset of OVCA cells with a CD44(+) phenotype in samples from patients with OVCA that possess CSC properties including the formation of spheroids in culture, self-renewal and the ability to be engrafted in immune-compromised mice. We next explored the use of immunotherapy using fusions of dendritic cells and OCIC to specifically target the OCIC subpopulations. Fusion cells (FCs) prepared in this way activated T cells to express elevated levels of IFN-γ with enhanced killing of CD44(+) OVCA cells. We envision a combined approach where conventional therapies such as chemotherapy kill the bulk of tumor cells, whereas OCIC-reactive cytotoxic T lymphocytes target the resistant OCIC fraction. A combined therapy such as this may represent a promising approach for the treatment of OVCA. PMID:21154809

  7. High avidity cytotoxic T lymphocytes can be selected into the memory pool but they are exquisitely sensitive to functional impairment.

    PubMed

    Brentville, Victoria A; Metheringham, Rachael L; Gunn, Barbara; Durrant, Lindy G

    2012-01-01

    High avidity cytotoxic T lymphocytes (CTL) are important in viral clearance and anti-tumor immunity, however, mechanisms for their optimal generation and maintenance in vivo remain unclear. Immunizing mice with an antibody-DNA vaccine encoding a single CTL epitope, induces a 100 fold higher avidity response than peptide vaccination with the identical epitope. The high avidity response is retained into memory and can be efficiently reactivated with an antibody-DNA boost. In contrast, reactivation of high avidity CTL with peptide, stimulated responses with a significant drop in avidity, suggesting loss or conversion of the high avidity CTL to lower avidity. Similarly, high avidity T cells maintained ex vivo were exquisitely sensitive to signaling with low doses of peptide (1 ng/ml) giving optimal TCR stimulation and resulting in retained avidity, proliferation and ability to kill specific targets. In contrast, high avidity T cells maintained ex vivo with supraoptimal TCR stimulation (10 µg/ml peptide) resulted in reduced avidity and failure to kill tumor cells. They also failed to proliferate, showed a significant increase in apoptosis and expressed high levels of the exhaustion marker programmed death-1 (PD-1) and low levels of the lymphocyte-activation gene 3 (LAG-3). This suggests high avidity T cells are recruited to the memory pool but can be lost by supraoptimal stimulation in vitro and in vivo. This is characterized by loss of function and an increase in cell death. The remaining CTL, exhibit low functional avidity that is reflected in reduced anti-tumor activity. This could contribute to failure of the immune system to control the growth of tumors and has implications for vaccination strategies and adoptive transfer of T cells. PMID:22829916

  8. Development of a lipopeptide-based therapeutic vaccine to treat chronic HBV infection. I. Induction of a primary cytotoxic T lymphocyte response in humans.

    PubMed Central

    Vitiello, A; Ishioka, G; Grey, H M; Rose, R; Farness, P; LaFond, R; Yuan, L; Chisari, F V; Furze, J; Bartholomeuz, R

    1995-01-01

    Our goal is to use peptide epitopes that are recognized by cytotoxic T lymphocytes (CTL) as immunogens for the development of prophylactic and therapeutic vaccines with chronic hepatitis B virus (HBV) infection being our first therapeutic target. Because most CTL peptide epitopes are poor immunogens, we specifically modified them by covalently attaching two additional components: a T helper peptide epitope and two lipid molecules. Using the murine influenza virus CTL epitope NP 147-155 as a model system, we found this construct to be highly immunogenic, and a single injection resulted in memory CTL induction that persisted for > 1 yr. Based on the animal studies, a vaccine was designed and tested for both safety and its ability to induce a primary CTL response in normal subjects. The three vaccine components included HBV core antigen peptide 18-27 as the CTL epitope, tetanus toxoid peptide 830-843 as the T helper peptide, and two palmitic acid molecules as the lipids. A dose escalation trial (5, 50, and 500 micrograms) carried out in 26 normal subjects showed that the vaccine was safe and able to induce a primary HBV-specific CTL response. A dose-response curve was observed and five out of five subjects responded to the 500-micrograms dose. PMID:7814635

  9. 7,12-dimethylbenz(a)anthracene-induced modulation of cytokines involved in cytotoxic t lymphocyte induction

    SciTech Connect

    House, R.V.; Pallardy, M.J.; Burleson, G.R.; Dean, J.H.

    1988-01-01

    Murine lymphocytes were exposed to the carcinogenic polycyclic aromatic hydrocarbon 7,12-dimethylbenz(a)anthracene (DMBA) and several cytokines were measured. Production of interleukin-1 by macrophages, interleukin-2 by EL-4 thymoma, and gamma interferon by activated splenic lymphocytes were not affected by DMBA. However, interleukin-5 (also known as T cell replacing factor) was significantly suppressed by DMBA. Cloned cytotoxic T lymphocyte activity was inhibited in a dose-dependent manner by DMBA and the suppression was significantly enhanced by addition of beta or gamma interferon. The results support the hypothesis that, rather than acting as a non-specific inhibitor of lymphocyte proliferation, DMBA-induced suppression of antigen-specific cytolysis is a mechanism directed against highly-specific cellular targets in the immune process.

  10. Induction of cytotoxic T lymphocyte response against Mycobacterial antigen using domain I of anthrax edema factor as antigen delivery system

    SciTech Connect

    Chandra, Subhash; Kaur, Manpreet; Midha, Shuchi; Gorantala, Jyotsna; Bhatnagar, Rakesh . E-mail: rakbhat01@yahoo.com

    2007-05-25

    We have investigated the efficiency of N-terminal 1-260 residues of Edema factor (EFn) as a delivery system for ESAT-6, an antigenic protein of Mycobacterium tuberculosis H{sub 37}R{sub v}, into the cytosol of mammalian cells. The EFn.ESAT-6 recombinant protein was obtained by genetic fusion of EFn and ESAT-6 DNA. Our data shows that in the presence of PA, EFn.ESAT-6 fusion protein is internalized into the cytosol of antigen presenting cells, and the splenocytes produced both Th1 and Th2 cytokines in vitro. Further, EFn.ESAT-6 elicited effective cytotoxicT lymphocyte (CTL) response in an in vitro CTL assay. This study for the first time demonstrates that EFn can be used as a vehicle to deliver heterologous proteins of therapeutic importance.

  11. Induction of myeloma-specific cytotoxic T lymphocytes ex vivo by CD40-activated B cells loaded with myeloma tumor antigens.

    PubMed

    Kim, Sang-Ki; Nguyen Pham, Thanh-Nhan; Nguyen Hoang, Tuyet Minh; Kang, Hyun-Kyu; Jin, Chun-Ji; Nam, Jong-Hee; Chung, Sang-Young; Choi, So-Jin-Na; Yang, Deok-Hwan; Kim, Yeo-Kyeoung; Chung, Ik-Joo; Kim, Hyeoung-Joon; Lee, Je-Jung

    2009-11-01

    We investigated to establish CD40-activated B cells (CD40-B cells) as alternative antigen-presenting cells (APCs) for the induction of myeloma-specific cytotoxic T lymphocytes (CTLs). To generate CD40-B cells, peripheral blood mononuclear cells were co-cultured with CD40L-transfected J558 cells in the presence of IL-4, insulin, transferrin, and cyclosporine for 14 days, and pulsed with myeloma lysates. The CD40-B cells consistently expressed high levels of CD80, CD86, CD54, CCR7, and HLA-DR. The CD40-B cells produced IL-12, IFN-gamma, and IL-6 during the culture period, but not IL-10. In addition, the CD40-B cells showed potent allogeneic T-cell stimulatory capacities that depended on the dose ratio and had the potential to polarize naïve T cells into Th1 subsets. The CD40-B cells loaded with tumor lysates induced strong target-specific CTLs, based on large numbers of IFN-gamma secreting cells and higher cytotoxic activity against target cells compared to the CD40-B cells without the tumor lysates. These results suggest that CD40-B cells loaded with myeloma lysates might provide alternative APCs for cellular immunotherapy in patients with myeloma. PMID:19277657

  12. Heteroclitic XBP1 peptides evoke tumor-specific memory cytotoxic T lymphocytes against breast cancer, colon cancer, and pancreatic cancer cells

    PubMed Central

    Bae, Jooeun; Samur, Mehmet; Munshi, Aditya; Hideshima, Teru; Keskin, Derin; Kimmelman, Alec; Lee, Ann-Hwee; Dranoff, Glen; Anderson, Kenneth C; Munshi, Nikhil C

    2015-01-01

    XBP1 is a critical transcriptional activator of the unfolded protein response (UPR), which increases tumor cell survival under prolonged endoplasmic reticulum (ER) stress and hypoxic conditions.This study was designed to evaluate the immunogenicity of heteroclitic XBP1 unspliced (US)184–192 (YISPWILAV) and heteroclictic XBP1 spliced (SP)367–375 (YLFPQLISV) HLA-A2 peptides, and to characterize the specific activities of XBP1 peptides-specific cytotoxic T lymphocytes (XBP1-CTL) against breast cancer, colon cancer, and pancreatic cancer cells.The XBP1-CTL had upregulated expression of critical T cell markers and displayed HLA-A2-restricted and antigen-specific activities against breast cancer, colon cancer and pancreatic cancer cells. XBP1-CTL were enriched withCD45RO+ memory CTL, which showed high expression of critical T cell markers (CD28, ICOS, CD69, CD40L), cell proliferation and antitumor activities as compared to CD45RO− non-memory CTL. The effector memory (EM: CD45RO+CCR7−) subset had the highest level of cell proliferation while the central memory (CM: CD45RO+CCR7+) subset demonstrated enhanced functional activities (CD107a degranulation, IFNγ/IL-2 production) upon recognition of the respective tumor cells. Furthermore, both the EM and CM XBP1-CTL subsets expressed high levels of Th1 transcription regulators Tbet and Eomes. The highest frequencies of IFNγ or granzyme B producing cells were detected within CM XBP1-CTL subset that were either Tbet+ or Eomes+ in responding to the tumor cells.These results demonstrate the immunotherapeutic potential of a cocktail of immunogenic HLA-A2 specific heteroclitic XBP1 US184–192 and heteroclictic XBP1 SP367–375 peptides to induce CD3+CD8+ CTL enriched for CM and EM cells with specific antitumor activities against a variety of solid tumors. PMID:25941601

  13. Programmed Death-Ligand 1 on Antigen-presenting Cells Facilitates the Induction of Antigen-specific Cytotoxic T Lymphocytes: Application to Adoptive T-Cell Immunotherapy.

    PubMed

    Goto, Tatsunori; Nishida, Tetsuya; Takagi, Erina; Miyao, Kotaro; Koyama, Daisuke; Sakemura, Reona; Hanajiri, Ryo; Watanabe, Keisuke; Imahashi, Nobuhiko; Terakura, Seitaro; Murata, Makoto; Kiyoi, Hitoshi

    2016-10-01

    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. Unexpectedly, PD-L1 blockade resulted in a less efficient induction of CMV-specific CTLs, suggesting that PD-L1 play a positive role in the induction of Ag-specific CTLs. For further evaluations and application to adoptive immunotherapy, we generated K562-based artificial APCs, which were retrovirally transduced with HLA class I molecules and various combinations of CD80/86 and PD-L1. K562/HLA+CD80/86+PD-L1 cells produced significantly higher induction of CMV-specific CTLs than K562/HLA or K562/HLA+CD80/86 cells without causing excessive differentiation or functional exhaustion of the induced CTLs, whereas PD-L1 itself did not have a stimulatory effect. Furthermore, only K562/HLA+CD80/86+PD-L1 cells pulsed with HLA-A*24:02-restricted Wilms tumor 1 (WT1) peptide clearly expanded WT1-specific CTLs from healthy donors. Our findings presumed that PD-L1 expressed on APCs along with CD80/86 enhanced the induction of Ag-specific CTLs probably depending on fine-tuning excessive stimulation of CD80/86, and that K562/HLA+CD80/86+PD-L1 cells has therapeutic potential as a novel type of artificial APCs for adoptive immunotherapy. PMID:27548033

  14. Targeting cytotoxic T lymphocytes for cancer immunotherapy

    PubMed Central

    Maher, J; Davies, E T

    2004-01-01

    In light of their preeminent role in cellular immunity, there is considerable interest in targeting of cytotoxic T-lymphocytes to cancer. This review summarises the active and passive immunotherapeutic approaches under development to achieve this goal, emphasising how recent advances in tumour immunology and gene transfer have impacted upon this field. PMID:15266309

  15. Induction of the Epstein-Barr virus latent membrane protein 2 antigen-specific cytotoxic T lymphocytes using human leukocyte antigen tetramer-based artificial antigen-presenting cells.

    PubMed

    Lu, Xiao-Ling; Liang, Zhi-Hui; Zhang, Cai-E; Lu, Sheng-Jun; Weng, Xiu-Fang; Wu, Xiong-Wen

    2006-03-01

    Cytotoxic T lymphocytes (CTLs) specific for the Epstein-Barr virus (EBV) latent membrane protein 2 (LMP2) antigen are important reagents for the treatment of some EBV-associated malignancies, such as EBV-positive Hodgkin's disease and nasopharyngeal carcinoma. However, the therapeutic amount of CTLs is often hampered by the limited supply of antigen-presenting cells. To address this issue, an artificial antigen-presenting cell (aAPC) was made by coating a human leukocyte antigen (HLA)-pLMP2 tetrameric complex, anti-CD28 antibody and CD54 molecule to a cell-sized latex bead, which provided the dual signals required for T cell activation. By co-culture of the HLA-A2-LMP2 bearing aAPC and peripheral blood mononuclear cells from HLA-A2 positive healthy donors, LMP2 antigen-specific CTLs were induced and expanded in vitro. The specificity of the aAPC-induced CTLs was demonstrated by both HLA-A2-LMP2 tetramer staining and cytotoxicity against HLA-A2-LMP2 bearing T2 cell, the cytotoxicity was inhibited by the anti-HLA class I antibody (W6/32). These results showed that LMP2 antigen-specific CTLs could be induced and expanded in vitro by the HLA-A2-LMP2-bearing aAPC. Thus, aAPCs coated with an HLA-pLMP2 complex, anti-CD28 and CD54 might be promising tools for the enrichment of LMP2-specific CTLs for adoptive immunotherapy. PMID:16518539

  16. Induction of a major histocompatibility complex class I-restricted cytotoxic T-lymphocyte response to a highly conserved region of human immunodeficiency virus type 1 (HIV-1) gp120 in seronegative humans immunized with a candidate HIV-1 vaccine.

    PubMed Central

    Johnson, R P; Hammond, S A; Trocha, A; Siliciano, R F; Walker, B D

    1994-01-01

    Efforts to induce broadly reactive immunity against human immunodeficiency virus type 1 (HIV-1) have been impaired by the extent of sequence variation exhibited by this lentivirus. Cytotoxic T lymphocytes (CTL) specific for other viruses such as influenza virus have been shown to mediate immunity against divergent viral strains, a property that is related to the ability of CTL to recognize processed antigen derived from conserved viral proteins. A recent candidate HIV-1 vaccine regimen has been described in which subjects receive a primary immunization with a recombinant vaccinia virus expressing gp160 and then a booster immunization with recombinant gp160. Volunteers immunized with this regimen have exhibited augmented humoral responses and have also developed CD4+ and CD8+ CTL specific for gp160. In this report, we have identified the epitopes recognized by CD4+ and CD8+ CTL obtained from two vaccines. An immunodominant CD8+ CTL response was HLA-A3.1 restricted and recognized a 10-amino-acid epitope (gp120/38-47) in a highly conserved region of gp120. CTL specific for the epitope gp120/38-47 were able to lyse targets sensitized with peptides corresponding to all known natural sequence variants in this region. In addition, other HLA class I-restricted CTL epitopes were identified in relatively conserved regions of gp120 and gp41, and CD4+ CTL were shown to recognize two different regions of gp120. Thus, in these two volunteers, immunization with a single strain of HIV-1 induced CD4+ and CD8+ CTL that are specific for multiple conserved regions of HIV-1 and would be expected to recognize a broad range of viral isolates. PMID:7908700

  17. Theiler's virus infection induces a specific cytotoxic T lymphocyte response.

    PubMed

    Pena Rossi, C; McAllister, A; Fiette, L; Brahic, M

    1991-12-01

    Theiler's virus, a murine picornavirus, persists in the central nervous system of susceptible mouse strains and causes chronic inflammation and primary demyelination. One of the current hypotheses is that demyelination is, at least in part, mediated by virus-specific cytotoxic T lymphocytes (CTL). However, it is generally assumed that picornaviruses do not induce CTL. In point of fact, their existence has only been demonstrated for Coxsackievirus B-3. To determine whether Theiler's virus induces a CTL response, we generated a murine mastocytoma cell line stably transfected with the coding region of the genome of Theiler's virus strain DA. Using these cells as targets we showed that infected DBA/2 mice, a susceptible strain, produce cytotoxic T lymphocytes. The cytotoxic activity was Theiler's-virus specific. It was for the most part mediated by CD8+ T lymphocytes and H-2 restricted. This is the first demonstration that a specific CTL response is generated during Theiler's virus infection.

  18. The cytotoxic T lymphocyte immune synapse at a glance.

    PubMed

    Dieckmann, Nele M G; Frazer, Gordon L; Asano, Yukako; Stinchcombe, Jane C; Griffiths, Gillian M

    2016-08-01

    The immune synapse provides an important structure for communication with immune cells. Studies on immune synapses formed by cytotoxic T lymphocytes (CTLs) highlight the dynamic changes and specialised mechanisms required to facilitate focal signalling and polarised secretion in immune cells. In this Cell Science at a Glance article and the accompanying poster, we illustrate the different steps that reveal the specialised mechanisms used to focus secretion at the CTL immune synapse and allow CTLs to be such efficient and precise serial killers.

  19. Protection Against Lethal Sendai Virus Infection by in vivo Priming of Virus-Specific Cytotoxic T Lymphocytes with a Free Synthetic Peptide

    NASA Astrophysics Data System (ADS)

    Kast, W. Martin; Roux, Laurent; Curren, Joseph; Blom, Hendrika J. J.; Voordouw, Arie C.; Meloen, Rob H.; Kolakofsky, Daniel; Melief, Cornelis J. M.

    1991-03-01

    The only peptide of Sendai virus that is recognized by cytotoxic T lymphocytes (CTL) in B6 mice was found with (i) the use of recombinant vaccinia virus constructs containing separate genes of Sendai virus and (ii) a set of overlapping peptides completely spanning the identified nucleoprotein (NP) gene product. This immunodominant NP peptide is recognized by Sendai virus-specific CTL that are known to have therapeutic effects in vivo. By subcutaneous immunization, this peptide induced Sendai virus and NP peptide-specific CTL memory responses in vivo. Most importantly, mice that had been immunized with this peptide were protected against a lethal virus dose, indicating that viral peptides can be used as antiviral T-cell vaccines. The induction of T-cell memory by free peptide immunization potentially has wide applicability in biology and medicine, including protection against infectious disease.

  20. Role of vitamin D in cytotoxic T lymphocyte immunity to pathogens and cancer.

    PubMed

    Sarkar, Surojit; Hewison, Martin; Studzinski, George P; Li, Yan Chun; Kalia, Vandana

    2016-01-01

    The discovery of vitamin D receptor (VDR) expression in immune cells has opened up a new area of research into immunoregulation by vitamin D, a niche that is distinct from its classical role in skeletal health. Today, about three decades since this discovery, numerous cellular and molecular targets of vitamin D in the immune system have been delineated. Moreover, strong clinical associations between vitamin D status and the incidence/severity of many immune-regulated disorders (e.g. infectious diseases, cancers and autoimmunity) have prompted the idea of using vitamin D supplementation to manipulate disease outcome. While much is known about the effects of vitamin D on innate immune responses and helper T (T(H)) cell immunity, there has been relatively limited progress on the frontier of cytotoxic T lymphocyte (CTL) immunity--an arm of host cellular adaptive immunity that is crucial for the control of such intracellular pathogens as human immunodeficiency virus (HIV), tuberculosis (TB), malaria, and hepatitis C virus (HCV). In this review, we discuss the strong historical and clinical link between vitamin D and infectious diseases that involves cytotoxic T lymphocyte (CTL) immunity, present our current understanding as well as critical knowledge gaps in the realm of vitamin D regulation of host CTL responses, and highlight potential regulatory connections between vitamin D and effector and memory CD8 T cell differentiation events during infections.

  1. Therapeutic potential of CD8+ cytotoxic T lymphocytes in SLE☆

    PubMed Central

    Puliaeva, I.; Puliaev, R.; Via, C.S.

    2011-01-01

    Recent evidence supports the idea that following a break in tolerance, CD8 cytotoxic T lymphocytes (CTL) may be an important but unrecognized mechanism for limiting expansion of autoreactive B cells. Failure of this mechanism could allow persistence of CD4 T cell driven polyclonal B cell activation resulting in clinical lupus. Although CD8 CTL failure may occur early in disease, work in mice supports the concept that therapeutic CTL enhancement may be both practical and beneficial in lupus. Devising such therapy for humans will first require an understanding of the in vivo mechanisms critical in CTL expansion and down regulation, particularly in the lupus setting which may differ from CTL generation in other clinical settings (e.g. tumors, infections). PMID:18725326

  2. Cross reactive antibody and cytotoxic T lymphocytes from avian influenza H9N2 infected chickens against homologous and heterologous avian influenza isolates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immunity against avian influenza (AI) is largely based on the induction of neutralizing antibodies produced against the hemagglutinin, although cytotoxic T lymphocytes (CTL’s) have been reported as critical for clearance of virus from infected cells. Antibody production against a particular virus ...

  3. Physiological changes induced in cardiac myocytes by cytotoxic T lymphocytes

    SciTech Connect

    Hassin, D.; Fixler, R.; Shimoni, Y.; Rubinstein, E.; Raz, S.; Gotsman, M.S.; Hasin, Y.

    1987-01-01

    The lethal hit induced by viral specific, sensitized, cytotoxic T lymphocytes (CTL) attacking virus-infected heart cells is important in the pathogenesis of viral myocarditis and reflects the key role of CTL in this immune response. The mechanisms involved are incompletely understood. Studies of the physiological changes induced in mengovirus-infected, cultured, neonatal, rat heart cells by CTL that had been previously sensitized by the same virus are presented. The CTL were obtained from spleens of mengovirus-infected, major histocompatibility complex (MHC) matched adult rats. Cell wall motion was measured by an optical method, action potentials with intracellular microelectrodes, and total exchangeable calcium content by /sup 45/Ca tracer measurements after loading the myocytes with /sup 45/Ca and then exposing them to CTL. After 50 min (mean time) of exposing mengovirus-infected myocytes to the CTL, the mechanical relaxation of the myocyte was slowed, with a subsequent slowing of beating rate and a reduced amplitude of contraction. Impaired relaxation progressed, and prolonged oscillatory contractions lasting up to several seconds appeared, with accompanying oscillations in the prolonged plateau phase of the action potentials. Arrest of the myocyte contractions appeared 98 min (mean time) after exposure to CTL. It is concluded that infection of cultured myocytes with mengovirus predisposes them to attack by mengovirus specific CTL, and that persistent dysfunction of the myocyte is preceded by reversible changes in membrane potential and contraction. This is suggestive of an altered calcium handling by the myocytes possibly resulting in the cytotoxic effect.

  4. Genetic modification of cytotoxic T lymphocytes to express cytokine receptors.

    PubMed

    Perna, Serena K; Savoldo, Barbara; Dotti, Gianpietro

    2014-01-01

    Adoptive transfer of tumor-infiltrating lymphocytes (TIL) or antigen-specific cytotoxic T lymphocytes (CTL) is safe and can be effective in cancer patients. Achievement of clinical responses in these patients is associated with the in vivo expansion and persistence of the transferred T lymphocytes. For this reason, recombinant human interleukin-2 (IL-2) is frequently used to support the in vivo survival of T lymphocytes infused into patients. However, IL-2 also causes important side effects. Thus, alternative strategies are highly demanded to limit cytokine-related off-target effects and to redirect the responsiveness of specific T-cell subsets to selected cytokines. Interleukin-7 (IL-7) is a promising alternative cytokine as it possesses the above mentioned properties. However, because its receptor is downregulated in ex vivo-expanded T cells, methods are required to restore their responsiveness to this homeostatic cytokine. In this chapter, we describe the methodology to obtain the ectopic expression of IL-7 receptor alpha (IL-7Rα) in antigen-specific CTL, using Epstein-Barr virus-specific CTL (EBV-CTL), as a model.

  5. Human cytotoxic T lymphocytes against the Plasmodium falciparum circumsporozoite protein.

    PubMed Central

    Malik, A; Egan, J E; Houghten, R A; Sadoff, J C; Hoffman, S L

    1991-01-01

    Cytotoxic T lymphocytes (CTL) against the circumsporozoite (CS) protein of malaria sporozoites protect against malaria in rodents. Although there is interest in developing human vaccines that induce CTL against the Plasmodium falciparum CS protein, humans have never been shown to produce CTL against any Plasmodium species protein or other parasite protein. We report that when peripheral blood mononuclear cells (PBMC) from three of four volunteers immunized with irradiated P. falciparum sporozoites were stimulated in vitro with a recombinant vaccinia virus expressing the P. falciparum CS protein or a peptide including only amino acids 368-390 of the P. falciparum CS protein [CS-(368-390)], the PBMC lysed autologous Epstein-Barr virus-transformed B cells transfected with the P. falciparum CS protein gene or incubated with CS-(368-390) tricosapeptide. Activity was antigen specific, genetically restricted, and dependent on CD8+ T cells. In one volunteer, seven peptides reflecting amino acids 311-400 were tested, and, as in B10.BR mice, CTL activity was only associated with the CS-(368-390) peptide. Development of an assay for studying human CTL against the CS and other malaria proteins and a method for constructing target cells by direct gene transfection provide a foundation for studying the role of CTL in protection against malaria. PMID:1707538

  6. Effects of extracellular pH and hypoxia on the function and development of antigen-specific cytotoxic T lymphocytes.

    PubMed

    Nakagawa, Yohko; Negishi, Yasuyuki; Shimizu, Masumi; Takahashi, Megumi; Ichikawa, Masao; Takahashi, Hidemi

    2015-10-01

    The major effector cells for cellular adaptive immunity are CD8(+) cytotoxic T lymphocytes (CTLs), which can recognize and kill virus-infected cells and tumor cells. Although CTLs exhibit strong cytolytic activity against target cells in vitro, a number of studies have demonstrated that their function is often impaired within tumors. Nevertheless, CTLs can regain their cytotoxic ability after escaping from the tumor environment, suggesting that the milieu created by tumors may affect the function of CTLs. As for the tumor environment, the patho-physiological situation present in vivo has been shown to differ from in vitro experimental conditions. In particular, low pH and hypoxia are the most important microenvironmental factors within growing tumors. In the present study, to determine the effect of these factors on CTL function in vivo, we examined the cytolytic activity of CTLs against their targets using murine CTL lines and the induction of these cells from memory cells under low pH or hypoxic conditions using antigen-primed spleen cells. The results indicated that both cytotoxic activity and the induction of functional CTLs were markedly inhibited under low pH. In contrast, in hypoxic conditions, although cytotoxic activity was almost unchanged, the induction of CTLs in vitro showed a slight enhancement, which was completely abrogated in low pH conditions. Therefore, antigen-specific CTL functions may be more vulnerable to low pH than to the oxygen concentration in vivo. The findings shown here provide new therapeutic approaches for controlling tumor growth by retaining CTL cytotoxicity through the maintenance of higher pH conditions.

  7. Common antiviral cytotoxic t-lymphocyte epitope for diverse arenaviruses.

    PubMed

    Oldstone, M B; Lewicki, H; Homann, D; Nguyen, C; Julien, S; Gairin, J E

    2001-07-01

    Members of the Arenaviridae family have been isolated from mammalian hosts in disparate geographic locations, leading to their grouping as Old World types (i.e., lymphocytic choriomeningitis virus [LCMV], Lassa fever virus [LFV], Mopeia virus, and Mobala virus) and New World types (i.e., Junin, Machupo, Tacaribe, and Sabia viruses) (C. J. Peters, M. J. Buchmeier, P. E. Rollin, and T. G. Ksiazek, p. 1521-1551, in B. N. Fields, D. M. Knipe, and P. M. Howley [ed.], Fields virology, 3rd ed., 1996; P. J. Southern, p. 1505-1519, in B. N. Fields, D. M. Knipe, and P. M. Howley [ed.], Fields virology, 3rd ed., 1996). Several types in both groups-LFV, Junin, Machupo, and Sabia viruses-cause severe and often lethal human diseases. By sequence comparison, we noted that eight Old World and New World arenaviruses share several amino acids with the nucleoprotein (NP) that consists of amino acids (aa) 118 to 126 (NP 118-126) (RPQASGVYM) of LCMV that comprise the immunodominant cytotoxic T-lymphocyte (CTL) epitope for H-2(d) mice (32). This L(d)-restricted epitope constituted >97% of the total bulk CTLs produced in the specific antiviral or clonal responses of H-2(d) BALB mice. NP 118-126 of the Old World arenaviruses LFV, Mopeia virus, and LCMV and the New World arenavirus Sabia virus bound at high affinity to L(d). The primary H-2(d) CTL anti-LCMV response as well as that of a CTL clone responsive to LCMV NP 118-126 recognized target cells coated with NP 118-126 peptides derived from LCMV, LFV, and Mopeia virus but not Sabia virus, indicating that a common functional NP epitope exists among Old World arenaviruses. Use of site-specific amino acid exchanges in the NP CTL epitope among these arenaviruses identified amino acids involved in major histocompatibility complex binding and CTL recognition.

  8. Characterization of antigen-presenting properties of tumour cells using virus-specific cytotoxic T lymphocytes.

    PubMed

    Spierings, D C; Agsteribbe, E; Wilschut, J; Huckriede, A

    2000-04-01

    Immunotherapy of tumours by induction of tumour-specific cytotoxic T-lymphocytes (CTLs) will only be effective for tumours with a functional antigen processing and presentation machinery. However, many tumours are known to down-regulate expression of major histocompatibility complex (MHC) class I molecules and/or to impair antigen processing. It is therefore desirable to evaluate the ability of a given tumour to present antigenic epitopes before developing an immunotherapy protocol. In this study we have used influenza virus as a tool to determine the antigen-presenting capacities of the murine neuroblastoma C1300 cell line NB41A3, a frequently used model for human neuroblastoma. Immunofluorescence analyses revealed low and moderate expression of MHC class I molecules Dd and Kk respectively. Nevertheless, infected NB41 A3 cells were lysed efficiently by influenza-specific CTLs. These results demonstrate that all steps of the antigen-processing pathway function properly in the NB tumour cells, and that the limited MHC class I expression suffices for efficient recognition by CTLs. In addition, lysis of the NB tumour cells shows that the cells are susceptible to CTL-induced apoptosis, a pathway that is often impaired in tumour cells. These characteristics make neuroblastoma a suitable target for immunotherapy. The presented assay allows evaluation of various immunological properties of tumour cells and, thus, represents a valuable tool to assess whether a given tumour will be susceptible to immunotherapy or not.

  9. Role of interferon-γ and cytotoxic T lymphocytes in intraocular tumor rejection.

    PubMed

    Ligocki, Ann J; Brown, Joseph R; Niederkorn, Jerry Y

    2016-05-01

    The eye is normally an immunosuppressive environment. This condition is better known as immune privilege and protects the eye from immune-mediated inflammation of tissues that cannot regenerate. However, immune privilege creates a dilemma for the eye when intraocular neoplasms arise. In some cases, immune privilege is suspended, resulting in the immune rejection of intraocular tumors. This study employed a mouse model in which interferon-γ-dependent intraocular tumor rejection occurs. We tested the hypothesis that this rejection requires interferon-γ for the generation and functional capacity of cytotoxic T lymphocyte-mediated rejection of intraocular tumors. Tumors grew progressively in the eyes of interferon-γ knockout mice, even though the mice generated tumor-specific cytotoxic T lymphocyte responses in the periphery. However, interferon-γ knockout mice rejected tumors that were introduced into extraocular sites. Subcutaneous tumor immunization before intraocular challenge led to tumor rejection and preservation of the eye in wild-type mice. By contrast, tumors grew progressively in the eyes of interferon-γ knockout mice despite their ability to generate peripheral tumor-specific cytotoxic T lymphocytes as well as the capacity of CD8(+) T cells to enter the eye as shown by the presence of CD8 and perforin message and CD3(+)CD8(+) leukocytes within the tumor-bearing eye. We found that cytotoxic T lymphocytes generated in wild-type mice and adoptively transferred into interferon-γ knockout mice mediated the rejection of intraocular tumors in interferon-γ knockout hosts. The results indicate that interferon-γ is critical for the initial priming and differentiation of cytotoxic T lymphocytes residing in the periphery to produce the most effect antitumor function within the eye.

  10. CRTAM determines the CD4+ cytotoxic T lymphocyte lineage.

    PubMed

    Takeuchi, Arata; Badr, Mohamed El Sherif Gadelhaq; Miyauchi, Kosuke; Ishihara, Chitose; Onishi, Reiko; Guo, Zijin; Sasaki, Yoshiteru; Ike, Hiroshi; Takumi, Akiko; Tsuji, Noriko M; Murakami, Yoshinori; Katakai, Tomoya; Kubo, Masato; Saito, Takashi

    2016-01-11

    Naive T cells differentiate into various effector T cells, including CD4(+) helper T cell subsets and CD8(+) cytotoxic T cells (CTL). Although cytotoxic CD4(+) T cells (CD4 +: CTL) also develop from naive T cells, the mechanism of development is elusive. We found that a small fraction of CD4(+) T cells that express class I-restricted T cell-associated molecule (CRTAM) upon activation possesses the characteristics of both CD4(+) and CD8(+) T cells. CRTAM(+) CD4(+) T cells secrete IFN-γ, express CTL-related genes, such as eomesodermin (Eomes), Granzyme B, and perforin, after cultivation, and exhibit cytotoxic function, suggesting that CRTAM(+) T cells are the precursor of CD4(+)CTL. Indeed, ectopic expression of CRTAM in T cells induced the production of IFN-γ, expression of CTL-related genes, and cytotoxic activity. The induction of CD4(+)CTL and IFN-γ production requires CRTAM-mediated intracellular signaling. CRTAM(+) T cells traffic to mucosal tissues and inflammatory sites and developed into CD4(+)CTL, which are involved in mediating protection against infection as well as inducing inflammatory response, depending on the circumstances, through IFN-γ secretion and cytotoxic activity. These results reveal that CRTAM is critical to instruct the differentiation of CD4(+)CTL through the induction of Eomes and CTL-related gene.

  11. CRTAM determines the CD4+ cytotoxic T lymphocyte lineage

    PubMed Central

    Takeuchi, Arata; Badr, Mohamed El Sherif Gadelhaq; Miyauchi, Kosuke; Ishihara, Chitose; Onishi, Reiko; Guo, Zijin; Sasaki, Yoshiteru; Ike, Hiroshi; Takumi, Akiko; Tsuji, Noriko M.; Murakami, Yoshinori; Katakai, Tomoya; Kubo, Masato

    2016-01-01

    Naive T cells differentiate into various effector T cells, including CD4+ helper T cell subsets and CD8+ cytotoxic T cells (CTL). Although cytotoxic CD4+ T cells (CD4+CTL) also develop from naive T cells, the mechanism of development is elusive. We found that a small fraction of CD4+ T cells that express class I–restricted T cell–associated molecule (CRTAM) upon activation possesses the characteristics of both CD4+ and CD8+ T cells. CRTAM+ CD4+ T cells secrete IFN-γ, express CTL-related genes, such as eomesodermin (Eomes), Granzyme B, and perforin, after cultivation, and exhibit cytotoxic function, suggesting that CRTAM+ T cells are the precursor of CD4+CTL. Indeed, ectopic expression of CRTAM in T cells induced the production of IFN-γ, expression of CTL-related genes, and cytotoxic activity. The induction of CD4+CTL and IFN-γ production requires CRTAM-mediated intracellular signaling. CRTAM+ T cells traffic to mucosal tissues and inflammatory sites and developed into CD4+CTL, which are involved in mediating protection against infection as well as inducing inflammatory response, depending on the circumstances, through IFN-γ secretion and cytotoxic activity. These results reveal that CRTAM is critical to instruct the differentiation of CD4+CTL through the induction of Eomes and CTL-related gene. PMID:26694968

  12. Effect of asbestos exposure on differentiation of cytotoxic T lymphocytes in mixed lymphocyte reaction of human peripheral blood mononuclear cells.

    PubMed

    Kumagai-Takei, Naoko; Nishimura, Yasumitsu; Maeda, Megumi; Hayashi, Hiroaki; Matsuzaki, Hidenori; Lee, Suni; Hiratsuka, Junichi; Otsuki, Takemi

    2013-07-01

    Asbestos fibers are associated with tumorigenicity, and are thought to cause mesothelioma. However, their effect on immune response remains unclear. We examined the effect of asbestos exposure on differentiation of cytotoxic T lymphocytes (CTLs) in mixed lymphocyte reactions (MLR) of human peripheral blood mononuclear cells (PBMCs) upon exposure to chrysotile B (CB) or crocidolite (CR) asbestos at 5 μg/ml for 7 days. Exposure to CB during MLR suppressed increases in the percentage and number of CD8⁺ T cells in response to allogenic cells. The cytotoxicity for allogenic targets decreased in PBMCs exposed to CB, but not CR, when compared with PBMCs without any exposure during MLR. Exposure to CB during MLR resulted in suppression of increases in granzyme B⁺ cells and IFN-γ⁺ cells. CB exposure also resulted in suppression of increases in CD45RO⁺ effector/memory cells and CD25⁺-activated cells in CD8⁺ lymphocytes, and a decrease in CD45RA⁺ cells. CB exposure suppressed the proliferation of CD8⁺ lymphocytes without an increase in annexin V⁺ apoptotic cells in CD8⁺ lymphocytes. Moreover, the production of IL-10, IFN-γ, and TNF-α, but not IL-2, decreased in the presence of CB. These results suggest that exposure to asbestos potentially suppresses the differentiation of cytotoxic T lymphocyte, accompanied by decreases in IFN-γ and TNF-α.

  13. Variant antigenic peptide promotes cytotoxic T lymphocyte adhesion to target cells without cytotoxicity

    PubMed Central

    Shotton, David M.; Attaran, Amir

    1998-01-01

    Timelapse video microscopy has been used to record the motility and dynamic interactions between an H-2Db-restricted murine cytotoxic T lymphocyte clone (F5) and Db-transfected L929 mouse fibroblasts (LDb) presenting normal or variant antigenic peptides from human influenza nucleoprotein. F5 cells will kill LDb target cells presenting specific antigen (peptide NP68: ASNENMDAM) after “browsing” their surfaces for between 8 min and many hours. Cell death is characterized by abrupt cellular rounding followed by zeiosis (vigorous “boiling” of the cytoplasm and blebbing of the plasma membrane) for 10–20 min, with subsequent cessation of all activity. Departure of cytotoxic T lymphocytes from unkilled target cells is rare, whereas serial killing is sometimes observed. In the absence of antigenic peptide, cytotoxic T lymphocytes browse target cells for much shorter periods, and readily leave to encounter other targets, while never causing target cell death. Two variant antigenic peptides, differing in nonamer position 7 or 8, also act as antigens, albeit with lower efficiency. A third variant peptide NP34 (ASNENMETM), which differs from NP68 in both positions and yet still binds Db, does not stimulate F5 cytotoxicity. Nevertheless, timelapse video analysis shows that NP34 leads to a significant modification of cell behavior, by up-regulating F5–LDb adhesive interactions. These data extend recent studies showing that partial agonists may elicit a subset of the T cell responses associated with full antigen stimulation, by demonstrating that TCR interaction with variant peptide antigens can trigger target cell adhesion and surface exploration without activating the signaling pathway that results in cytotoxicity. PMID:9861010

  14. Polymer nanoparticles for cross-presentation of exogenous antigens and enhanced cytotoxic T-lymphocyte immune response

    PubMed Central

    Song, Chanyoung; Noh, Young-Woock; Lim, Yong Taik

    2016-01-01

    Effective induction of an antigen-specific cytotoxic T lymphocyte (CTL) immune response is one of the key goals of cancer immunotherapy. We report the design and fabrication of polyethylenimine (PEI)-coated polymer nanoparticles (NPs) as efficient antigen-delivery carriers that can induce antigen cross-presentation and a strong CTL response. After synthesis of poly(d,l-lactide-co-glycolide) (PLGA) NPs containing ovalbumin (OVA) by the double-emulsion solvent-evaporation method, cationic-charged PLGA NPs were generated by coating them with PEI. In a methyl tetrazolium salt assay, no discernible cytotoxic effect of PEI-coated PLGA (OVA) NPs was observed. The capacity and mechanism of PEI-coated PLGA (OVA) NPs for antigen delivery and cross-presentation on dendritic cells (DCs) were determined by fluorescence microscopy and flow cytometry. PEI-coated PLGA (OVA) NPs were internalized efficiently via phagocytosis or macropinocytosis in DCs and induced efficient cross-presentation of the antigen on MHC class I molecules via both endosome escape and a lysosomal processing mechanism. The DCs treated with PEI-coated PLGA (OVA) NPs induced a release of IL-2 cytokine from OVA-specific CD8-OVA1.3 T cells more efficiently than DCs treated with PLGA (OVA) NPs. Therefore, the PEI-coated PLGA (OVA) NPs can induce antigen cross-presentation and are expected to be used for induction of a strong CTL immune response and for efficient anticancer immunotherapy. PMID:27540289

  15. The 22,000-kilodalton protein of respiratory syncytial virus is a major target for Kd-restricted cytotoxic T lymphocytes from mice primed by infection.

    PubMed Central

    Openshaw, P J; Anderson, K; Wertz, G W; Askonas, B A

    1990-01-01

    Recombinant vaccinia viruses containing the 22-kilodalton protein (matrixlike or 22K protein) or phosphoprotein gene from respiratory syncytial virus were constructed. These recombinant viruses expressed proteins which were immunoprecipitated by appropriate respiratory syncytial virus antibodies and comigrated with authentic proteins produced by respiratory syncytial virus infection. The new recombinant viruses (and others previously described containing the attachment glycoprotein, fusion, or nucleoprotein genes of respiratory syncytial virus) were used to infect target cells for cultured polyclonal cytotoxic T lymphocytes generated from the spleens of BALB/c or DBA/2 mice primed by intranasal infection with respiratory syncytial virus. Respiratory syncytial virus-specific cytotoxic T lymphocytes (CTL) showed strong Kd (but not Dd)-restricted recognition of the 22K protein. As previously reported, the fusion protein and nucleoprotein were both seen by CTL, but recognition of these proteins was comparatively weak. There was no detectable recognition of other respiratory syncytial virus proteins tested (including phosphoprotein). 22K protein-specific splenic memory CTL persisted for at least 11 months after infection of BALB/c mice. Priming BALB/c mice with recombinant vaccinia virus containing the 22K protein gene induced respiratory syncytial virus-specific memory CTL at lower levels than that previously reported following infection with a similar recombinant containing the fusion protein gene. These data identify the 22K protein as a major target antigen for respiratory syncytial virus-specific CTL from H-2d mice primed by respiratory syncytial virus infection. Images PMID:2319650

  16. Inhibitory effects of various oxygenated sterols on the differentiation and function of tumor-specific cytotoxic T lymphocytes

    SciTech Connect

    Spangrude, G.J.; Sherris, D.; Daynes, R.A.

    1982-05-01

    Irradiation of skin with ultraviolet light (UVL) is capable of causing many biological and biochemical changes in this complex organ. One early consequence is the oxidation of epidermal plasma membrane cholesterol, causing the induction of a wide variety of photoproducts. It is well recognized that some oxygenated sterols possess potent biological activity on mammalian cells by their ability to inhibit endogeneous mevalonate and cholesterol biosynthesis. In the few immunological systems that have been studied, there is general agreement that lymphocyte function is altered in the presence of certain oxygenated sterols. Insight into the biochemical basis for altered lymphocyte function is lacking, as both afferent and efferent blockades have been suggested. These studies were undertaken to determine the effect of various oxygenated sterols (representing a number of known cholesterol-derived photoproducts) on the generation (afferent) and function (efferent) of cytotoxic T lymphocytes (CTLs). Cell-mediated immune responses which result in the generation of both alloantigen-specific and syngeneic tumor-specific CTLs were evaluated. (JMT)

  17. Mouse hepatitis virus-specific cytotoxic T lymphocytes protect from lethal infection without eliminating virus from the central nervous system.

    PubMed Central

    Stohlman, S A; Bergmann, C C; van der Veen, R C; Hinton, D R

    1995-01-01

    Acute infection of the central nervous system by the neurotropic JHM strain of mouse hepatitis virus (JHMV) induces nucleocapsid protein specific cytotoxic T lymphocytes (CTL) not found in the periphery (S. Stohlman, S. Kyuwa, J. Polo, D. Brady, M. Lai, and C. Bergmann, J. Virol. 67:7050-7059, 1993). Peripheral induction of CTL specific for the nucleocapsid protein of JHMV by vaccination with recombinant vaccinia viruses was unable to provide significant protection to a subsequent lethal virus challenge. By contrast, the transfer of nucleoprotein-specific CTL protected mice from a subsequent lethal challenge by reducing virus replication within the central nervous system, demonstrating the importance of the CTL response to this epitope in JHMV infection. Transfer of these CTL directly into the central nervous system was at least 10-fold more effective than peripheral transfer. Histological analysis indicated that the CTL reduced virus replication in ependymal cells, astrocytes, and microglia. Although the CTL were relatively ineffective at reducing virus replication in oligodendroglia, survivors showed minimal evidence of virus persistence within the central nervous system and no evidence of chronic ongoing demyelination. PMID:7815531

  18. Functional Alteration of Natural Killer Cells and Cytotoxic T Lymphocytes upon Asbestos Exposure and in Malignant Mesothelioma Patients

    PubMed Central

    Nishimura, Yasumitsu; Kumagai-Takei, Naoko; Matsuzaki, Hidenori; Lee, Suni; Maeda, Megumi; Kishimoto, Takumi; Fukuoka, Kazuya; Nakano, Takashi; Otsuki, Takemi

    2015-01-01

    Malignant mesothelioma is caused by exposure to asbestos, which is known to have carcinogenic effects. However, the development of mesothelioma takes a long period and results from a low or intermediate dose of exposure. These findings have motivated us to investigate the immunological effects of asbestos exposure and analyze immune functions of patients with mesothelioma and pleural plaque, a sign of exposure to asbestos. Here, we review our knowledge concerning natural killer (NK) cells and cytotoxic T lymphocytes (CTL). NK cells showed impaired cytotoxicity with altered expression of activating receptors upon exposure to asbestos, while induction of granzyme+ cells in CD8+ lymphocytes was suppressed by asbestos exposure. It is interesting that a decrease in NKp46, a representative activating receptor, is common between NK cells in PBMC culture with asbestos and those of mesothelioma patients. Moreover, it was observed that CD8+ lymphocytes may be stimulated by some kind of “nonself” cells in plaque-positive individuals and in mesothelioma patients, whereas CTL in mesothelioma is impaired by poststimulation maintenance of cytotoxicity. These findings suggest that analysis of immunological parameters might contribute to the evaluation of health conditions of asbestos-exposed individuals and to a greater understanding of the pathology of malignant mesothelioma. PMID:26161391

  19. Delayed Cytotoxic T Lymphocyte-Associated Protein 4-Immunoglobulin Treatment Reverses Ongoing Alloantibody Responses and Rescues Allografts From Acute Rejection.

    PubMed

    Young, J S; Chen, J; Miller, M L; Vu, V; Tian, C; Moon, J J; Alegre, M-L; Sciammas, R; Chong, A S

    2016-08-01

    Antibody-mediated rejection has emerged as the leading cause of late graft loss in kidney transplant recipients, and inhibition of donor-specific antibody production should lead to improved transplant outcomes. The fusion protein cytotoxic T lymphocyte-associated protein 4-immunoglobulin (CTLA4-Ig) blocks T cell activation and consequently inhibits T-dependent B cell antibody production, and the current paradigm is that CTLA4-Ig is effective with naïve T cells and less so with activated or memory T cells. In this study, we used a mouse model of allosensitization to investigate the efficacy of continuous CTLA4-Ig treatment, initiated 7 or 14 days after sensitization, for inhibiting ongoing allospecific B cell responses. Delayed treatment with CTLA4-Ig collapsed the allospecific germinal center B cell response and inhibited alloantibody production. Using adoptively transferred T cell receptor transgenic T cells and a novel approach to track endogenous graft-specific T cells, we demonstrate that delayed CTLA4-Ig minimally inhibited graft-specific CD4(+) and T follicular helper responses. Remarkably, delaying CTLA4-Ig until day 6 after transplantation in a fully mismatched heart transplant model inhibited alloantibody production and prevented acute rejection, whereas transferred hyperimmune sera reversed the effects of delayed CTLA4-Ig. Collectively, our studies revealed the unexpected efficacy of CTLA4-Ig for inhibiting ongoing B cell responses even when the graft-specific T cell response was robustly established. PMID:26928966

  20. Novel epitope evoking CD138 antigen-specific cytotoxic T lymphocytes targeting multiple myeloma and other plasma cell disorders.

    PubMed

    Bae, Jooeun; Tai, Yu-Tzu; Anderson, Kenneth C; Munshi, Nikhil C

    2011-11-01

    The development of an immunotherapeutic strategy targeting CD138 antigen could potentially represent a new treatment option for multiple myeloma (MM). This study evaluated the immune function of CD138 peptide-specific cytotoxic T lymphocytes (CTL), generated ex vivo using an HLA-A2-specific CD138 epitope against MM cells. A novel immunogenic HLA-A2-specific CD138(260-268) (GLVGLIFAV) peptide was identified from the full-length protein sequence of the CD138 antigen, which induced CTL specific to primary CD138(+) MM cells. The peptide-induced CD138-CTL contained a high percentage of CD8(+) activated/memory T cells with a low percentage of CD4(+) T cell and naive CD8(+) T cell subsets. The CTL displayed HLA-A2-restricted and CD138 antigen-specific cytotoxicity against MM cell lines. In addition, CD138-CTL demonstrated increased degranulation, proliferation and γ-interferon secretion to HLA-A2(+) /CD138(+) myeloma cells, but not HLA-A2(-) /CD138(+) or HLA-A2(+) /CD138(-) cells. The immune functional properties of the CD138-CTL were also demonstrated using primary HLA-A2(+) /CD138(+) cells isolated from myeloma patients. In conclusion, a novel immunogenic CD138(260-268) (GLVGLIFAV) peptide can induce antigen-specific CTL, which might be useful for the treatment of MM patients with peptide-based vaccine or cellular immunotherapy strategies. PMID:21902685

  1. Novel epitope evoking CD138 antigen-specific cytotoxic T lymphocytes targeting multiple myeloma and other plasma cell disorders

    PubMed Central

    Bae, Jooeun; Tai, Yu-Tzu; Anderson, Kenneth C.; Munshi, Nikhil C.

    2012-01-01

    The development of an immunotherapeutic strategy targeting CD138 antigen could potentially represent a new treatment option for multiple myeloma (MM). This study evaluated the immune function of CD138 peptide-specific cytotoxic T lymphocytes (CTL), generated ex vivo using an HLA-A2-specific CD138 epitope against MM cells. A novel immunogenic HLA-A2-specific CD138260-268 (GLVGLIFAV) peptide was identified from the full-length protein sequence of the CD138 antigen, which induced CTL specific to primary CD138+ MM cells. The peptide-induced CD138-CTL contained a high percentage of CD8+ activated/memory T cells with a low percentage of CD4+ T cell and naive CD8+ T cell subsets. The CTL displayed HLA-A2-restricted and CD138 antigen-specific cytotoxicity against MM cell lines. In addition, CD138-CTL demonstrated increased degranulation, proliferation and γ–interferon secretion to HLA-A2+/CD138+ myeloma cells, but not HLA-A2−/CD138+ or HLA-A2+/CD138− cells. The immune functional properties of the CD138-CTL were also demonstrated using primary HLA-A2+/CD138+ cells isolated from myeloma patients. In conclusion, a novel immunogenic CD138260-268 (GLVGLIFAV) peptide can induce antigen-specific CTL, which might be useful for the treatment of MM patients with peptide-based vaccine or cellular immunotherapy strategies. PMID:21902685

  2. Increased prevalence of peripheral blood granulysin-producing cytotoxic T lymphocytes in preeclampsia.

    PubMed

    Molvarec, Attila; Shiozaki, Arihiro; Ito, Mika; Toldi, Gergely; Stenczer, Balázs; Szarka, András; Nakashima, Akitoshi; Vásárhelyi, Barna; Rigó, János; Saito, Shigeru

    2011-09-01

    Preeclampsia (PE) is a severe complication of pregnancy characterized by an excessive maternal systemic inflammatory response with activation of both the innate and adaptive arms of the immune system. Granulysin is a cytolytic and pro-inflammatory molecule expressed by activated human cytotoxic T lymphocytes and natural killer (NK) cells. Recent data show that serum granulysin levels are elevated in preeclampsia. The purpose of this study was to determine whether the proportion of peripheral blood cytotoxic T lymphocytes and NK cells that express intracellular granulysin is altered in PE. Twenty-two preeclamptic patients and 29 healthy pregnant women were involved in this case-control study. Intracellular granulysin expression of lymphocytes was determined with flow cytometric examination. In healthy pregnant women, the majority of NK cells and a small fraction of cytotoxic T cells expressed granulysin in their cytoplasma (median (25-75 percentile): 53.5 (45.6-68.0)% and 13.8 (8.5-23.1)%, respectively). In PE, the percentage of granulysin-positive cytotoxic T lymphocytes was markedly increased, while the proportion of granulysin-producing NK cells was unchanged as compared to healthy pregnant women (for cytotoxic T cells: 34.1 (19.3-45.6)%, p<0.001; for NK cells: 57.2 (42.9-74.9)%, p>0.05). Maternal age of healthy pregnant women showed a significant inverse correlation with the frequency of granulysin-expressing NK cells (Spearman R=-0.44, p<0.05), while their BMI correlated positively with the proportions of granulysin-positive cytotoxic T cells and NK cells (Spearman R=0.43, p<0.05 for both). In conclusion, the majority of circulating NK cells but only a small population of cytotoxic T cells shows intracellular granulysin expression in normal pregnancy. In preeclampsia, the proportion of granulysin-producing cytotoxic T cells in the peripheral blood is markedly increased, which might contribute to the development of the pro-inflammatory Th1-type immune responses

  3. Cytotoxic T-lymphocyte activity specific for hemagglutinin (H) protein of canine distemper virus in dogs.

    PubMed

    Hirama, Kyoko; Togashi, Ken-ichi; Wakasa, Chiaki; Yoneda, Misako; Nishi, Toshiya; Endo, Yasuyuki; Miura, Ryuichi; Tsukiyama-Kohara, Kyoko; Kai, Chieko

    2003-01-01

    Cytotoxic T-lymphocyte (CTL) responses to hemagglutinin (H) protein of canine distemper virus (CDV) were evaluated in dogs using the replication-deficient adenovirus protein expression system. Skin fibroblasts were isolated from two dogs and were infected with recombinant adenovirus bearing the CDV-H gene (Ade-CDVH). CTL assay was performed using fibroblasts expressing CDV-H protein as target cells and peripheral blood lymphocytes (PBL) collected from the same dogs one week after immunization of CDV as effector cells. Specific cytotoxic activity was observed against autologous but not heterologous fibroblasts expressing CDV-H protein. These results indicate that the CTL epitope(s) were localized in the H protein. PMID:12576714

  4. Cytotoxic T lymphocyte antigen-4 expression in esophageal carcinoma: implications for prognosis

    PubMed Central

    Zhang, Xiao-Fei; Pan, Ke; Weng, De-Sheng; Chen, Chang-Long; Wang, Qi-Jing; Zhao, Jing-Jing; Pan, Qiu-Zhong; Liu, Qing; Jiang, Shan-Shan; Li, Yong-Qiang; Zhang, Hong-Xia; Xia, Jian-Chuan

    2016-01-01

    To examine the relationship between cytotoxic T lymphocyte antigen-4 (CTLA-4) expression and esophageal carcinoma prognosis, CTLA-4 expression was immunohistochemically detected in paraffin-embedded primary tumor specimens from 158 patients with esophageal cancer. CTLA-4 was detected in the cytoplasm and cell membranes of esophageal cancer cells and in interstitial lymphocytes. In univariate analyses (log-rank), higher interstitial CTLA-4+ lymphocyte density and higher tumor CTLA-4 expression were associated with shorter overall survival (OS). After controlling for age and clinical stage, multivariate analysis (Cox) found that tumor CTLA-4 expression was an independent predictor of shorter OS (HR 2.016, P = 0.004). These results indicate that CTLA-4 expression in the tumor environment (both lymphocytes and tumor cells) is associated with poorer prognosis. In addition, CTLA-4 profiles may be useful for predicting the benefits and toxicity of CTLA-4 blockade in patients with esophageal carcinoma. PMID:27050369

  5. A novel immunogenic CS1-specific peptide inducing antigen-specific cytotoxic T lymphocytes targeting multiple myeloma

    PubMed Central

    Bae, Jooeun; Song, Weihua; Smith, Robert; Daley, John; Tai, Yu-Tzu; Anderson, Kenneth C.; Munshi, Nikhil C.

    2013-01-01

    The CS1 antigen provides a unique target for the development of an immunotherapeutic strategy to treat patients with multiple myeloma (MM). This study aimed to identify HLA-A2+ immunogenic peptides from the CS1 antigen, which induce peptide-specific cytotoxic T lymphocytes (CTL) against HLA-A2+ MM cells. We identified a novel immunogenic HLA-A2-specific CS1239–247 (SLFVLGLFL) peptide, which induced CS1-specific CTL (CS1-CTL) to MM cells. The CS1-CTL showed a distinct phenotype, with an increased percentage of effector memory and activated CTL and a decreased percentage of naive CTL. CS1239–247 peptide-specific CD8+ T cells were detected by DimerX analyses and demonstrated functional activities specific to the peptide. The CTL displayed HLA-A2-restricted and antigen-specific cytotoxicity, proliferation, degranulation and γ-interferon (IFN-γ)production against both primary MM cells and MM cell lines. In addition, the effector memory cells subset (CD45RO−CCR7−/CD3+CD8+) within CS1-CTL showed a higher level of CD107a degranulation and IFN-γproduction as compared to effector cells (CD45RO−CCR7−/CD3+CD8+) against HLA-A2+ primary MM cells or MM cell lines. In conclusion, this study introduced a novel immunogenic HLA-A2-specific CS1239–247 peptide capable of inducing antigen-specific CTL against MM cells that will provide a framework for its application as a novel MM immunotherapy. PMID:22533610

  6. A novel immunogenic CS1-specific peptide inducing antigen-specific cytotoxic T lymphocytes targeting multiple myeloma.

    PubMed

    Bae, Jooeun; Song, Weihua; Smith, Robert; Daley, John; Tai, Yu-Tzu; Anderson, Kenneth C; Munshi, Nikhil C

    2012-06-01

    The CS1 antigen provides a unique target for the development of an immunotherapeutic strategy to treat patients with multiple myeloma (MM). This study aimed to identify HLA-A2(+) immunogenic peptides from the CS1 antigen, which induce peptide-specific cytotoxic T lymphocytes (CTL) against HLA-A2(+) MM cells. We identified a novel immunogenic HLA-A2-specific CS1(239-247) (SLFVLGLFL) peptide, which induced CS1-specific CTL (CS1-CTL) to MM cells. The CS1-CTL showed a distinct phenotype, with an increased percentage of effector memory and activated CTL and a decreased percentage of naïve CTL. CS1(239-247) peptide-specific CD8(+) T cells were detected by DimerX analyses and demonstrated functional activities specific to the peptide. The CTL displayed HLA-A2-restricted and antigen-specific cytotoxicity, proliferation, degranulation and γ-interferon (IFN-γ) production against both primary MM cells and MM cell lines. In addition, the effector memory cells subset (CD45RO(+) CCR7(-) /CD3(+) CD8(+) ) within CS1-CTL showed a higher level of CD107a degranulation and IFN-γ production as compared to effector cells (CD45RO(-) CCR7(-) /CD3(+) CD8(+) ) against HLA-A2(+) primary MM cells or MM cell lines. In conclusion, this study introduced a novel immunogenic HLA-A2-specific CS1(239-247) peptide capable of inducing antigen-specific CTL against MM cells that will provide a framework for its application as a novel MM immunotherapy. PMID:22533610

  7. Effective Cytotoxic T Lymphocyte Targeting of Persistent HIV-1 during Antiretroviral Therapy Requires Priming of Naive CD8+ T Cells

    PubMed Central

    Smith, Kellie N.; Mailliard, Robbie B.; Piazza, Paolo A.; Fischer, Will; Korber, Bette T.; Fecek, Ronald J.; Ratner, Deena; Gupta, Phalguni; Mullins, James I.

    2016-01-01

    ABSTRACT Curing HIV-1 infection will require elimination of persistent cellular reservoirs that harbor latent virus in the face of combination antiretroviral therapy (cART). Proposed immunotherapeutic strategies to cure HIV-1 infection include enhancing lysis of these infected cells by cytotoxic T lymphocytes (CTL). A major challenge in this strategy is overcoming viral immune escape variants that have evaded host immune control. Here we report that naive CD8+ T cells from chronic HIV-1-infected participants on long-term cART can be primed by dendritic cells (DC). These DC must be mature, produce high levels of interleukin 12p70 (IL-12p70), be responsive to CD40 ligand (CD40L), and be loaded with inactivated, autologous HIV-1. These DC-primed CD8+ T cell responders produced high levels of gamma interferon (IFN-γ) in response to a broad range of both conserved and variable regions of Gag and effectively killed CD4+ T cell targets that were either infected with the autologous latent reservoir-associated virus or loaded with autologous Gag peptides. In contrast, HIV-1-specific memory CD8+ T cells stimulated with autologous HIV-1-loaded DC produced IFN-γ in response to a narrow range of conserved and variable Gag peptides compared to the primed T cells and most notably, displayed significantly lower cytolytic function. Our findings highlight the need to selectively induce new HIV-1-specific CTL from naive precursors while avoiding activation of existing, dysfunctional memory T cells in potential curative immunotherapeutic strategies for HIV-1 infection. PMID:27247230

  8. Identification of ribosomal protein L19 as a novel tumor antigen recognized by autologous cytotoxic T lymphocytes in lung adenocarcinoma.

    PubMed

    Kuroda, Koji; Takenoyama, Mitsuhiro; Baba, Tetsuro; Shigematsu, Yoshiki; Shiota, Hironobu; Ichiki, Yoshinobu; Yasuda, Manabu; Uramoto, Hidetaka; Hanagiri, Takeshi; Yasumoto, Kosei

    2010-01-01

    The purpose of the present study was to identify a novel tumor-specific antigen capable of inducing a specific cellular immune response in lung cancer patients. The co-culture of regional lymph node lymphocytes and the CD80-transfected autologous lung adenocarcinoma cell line H1224L resulted in a successful induction of bulk cytotoxic T lymphocytes (CTL). CTL clone L7/8 was established by the limiting dilution method from these bulk CTLs and lysed H1224L but not autologous Epstein-Barr virus-transformed B cells or K562. The CTL clone also recognized allogeneic lung cancer cell lines in an HLA-A*31012-restricted manner. Using the CTL clone, an antigen-coding gene was identified using the cDNA expression cloning technique, which encodes ribosomal protein L19 (RPL19). Finally, a 9 mer antigenic peptide was identified by means of construction of mini-genes. RPL19 was overexpressed in the lung cancer tissue from patient H1224. All of the normal tissues examined expressed lower levels of RPL19 mRNA than that of the lung cancer tissue. RPL19 was also found to be overexpressed in 12 of 30 (40%) non-small-cell lung cancer tissues by immunohistochemical staining. The expression level of RPL19 in tumor cell lines correlated positively with the production of interferon (IFN)-gammaby CTL clone L7/8 in response to such cell lines. In addition, the suppression of RPL19 expression by transfection with small interfering RNA resulted in the suppression of cyclinD1, D3 synthesis, and the growth inhibition of lung cancer cell lines overexpressing RPL19. Therefore, this growth suppression could be ascribed to the inhibition of the cell cycle. These results may indicate that RPL19 is a novel overexpressed antigen which may therefore be a useful candidate as a target for specific immunotherapy.

  9. Cytotoxic T lymphocyte response to hepatitis C virus-derived peptides containing the HLA A2.1 binding motif.

    PubMed Central

    Cerny, A; McHutchison, J G; Pasquinelli, C; Brown, M E; Brothers, M A; Grabscheid, B; Fowler, P; Houghton, M; Chisari, F V

    1995-01-01

    The HLA class I-restricted cytotoxic T lymphocyte (CTL) response is a major defense mechanism in viral infections. It has been suggested that the CTL response may contribute to viral clearance and liver cell injury during hepatitis C virus (HCV) infection. To test this hypothesis requires an understanding of the characteristics of HCV-specific cytotoxic effector cells and identification of the target antigens to which they respond. To begin this process we stimulated peripheral blood mononuclear cells (PBMC) from a group of HLA-A2 positive patients with chronic hepatitis C with a panel of 130 HCV-derived peptides containing the HLA-A2 binding motif. Effector cells were tested for their capacity to lyse HLA-A2-matched target cells that were either sensitized with peptide or infected with a vaccinia virus construct containing HCV sequences. Using this approach we have identified nine immunogenic peptides in HCV, three of which are derived from the putative core protein, three from the nonstructural (NS) 3 domain, two from NS4 and one from NS5. Selected responses were shown to be HLA-A2 restricted, mediated by CD8+ T cells and to recognize endogenously synthesized viral antigen. Unexpectedly, peptide-specific CTL responses could also be induced in sero-negative individuals, suggesting in vitro activation of naive CTL precursors. The precursor frequency of peptide-specific CTL was 10 to 100-fold higher in infected patients compared to uninfected controls, and the responses were greatly diminished by removal of CD45 RO+ (memory) T cells. Further quantitative studies are clearly required to establish whether a correlation exists between the HCV-specific CTL response and the clinical course of this disease. Definition of the molecular targets of the human CTL response to HCV creates this opportunity, and may also contribute to the development of a T cell-based HCV vaccine. PMID:7860734

  10. Dengue virus protein recognition by virus-specific murine CD8+ cytotoxic T lymphocytes.

    PubMed Central

    Rothman, A L; Kurane, I; Lai, C J; Bray, M; Falgout, B; Men, R; Ennis, F A

    1993-01-01

    The identification of the protein targets for dengue virus-specific T lymphocytes may be useful for planning the development of subunit vaccines against dengue. We studied the recognition by murine dengue virus-specific major histocompatibility complex class I-restricted, CD8+ cytotoxic T lymphocytes (CTL) of dengue virus proteins using recombinant vaccinia viruses containing segments of the dengue virus genome. CTL from H-2k mice recognized a single serotype-cross-reactive epitope on the nonstructural (NS) protein NS3. CTL from H-2b mice recognized a serotype-cross-reactive epitope that was localized to NS4a or NS4b. CTL from H-2d mice recognized at least three epitopes: a serotype-specific epitope on one of the structural proteins, a serotype-cross-reactive epitope on NS3, and a serotype-cross-reactive epitope on NS1 or NS2a. Our findings demonstrate the limited recognition of dengue virus proteins by CTL from three inbred mouse strains and the predominance of CTL epitopes on dengue virus nonstructural proteins, particularly NS3. Since human dengue virus-specific CTL show similar patterns of recognition, these findings suggest that nonstructural proteins should be considered in designing vaccines against dengue. PMID:7678307

  11. Identification of new HLA-A*0201-restricted cytotoxic T lymphocyte epitopes from neuritin.

    PubMed

    Yang, Zhao; Zhao, Tianzhi; Liu, Yong; Gong, Zili; Cheng, Saiyu; Yang, Qingwu

    2013-08-01

    Identification of cytotoxic T lymphocyte (CTL) epitopes from additional tumor antigens is essential for the development of specific immunotherapy of malignant tumors. Neuritin, a recently discovered antigen overexpressed in astrocytoma, is considered to be a promising target for biological therapy. In the present study, we predicted and identified HLA-A2-restricted CTL epitopes from neuritin by using the following four-step procedure: (1) computer-based epitope prediction from the amino acid sequence of neuritin; (2) peptide-binding assay to determine the affinity of the predicted peptide with HLA-A2.1 molecule; (3) stimulation of primary T cell response against the predicted peptides in vitro; and (4) testing of the induced CTLs toward target cells expressing neuritin and HLA-A2.1. The results demonstrated that effectors induced by peptides of neuritin containing residues 13-21, 121-129 and 4-12 could specifically-secrete interferon-γ and lyse target cells. Our results indicate that these peptides are new HLA-A2.1-restricted CTL epitopes, and may serve as valuable tools for astrocytoma immunotherapy. PMID:23754640

  12. Hitchhiking nanoparticles: Reversible coupling of lipid-based nanoparticles to cytotoxic T lymphocytes.

    PubMed

    Wayteck, Laura; Dewitte, Heleen; De Backer, Lynn; Breckpot, Karine; Demeester, Jo; De Smedt, Stefaan C; Raemdonck, Koen

    2016-01-01

    Following intravenous injection of anti-cancer nanomedicines, many barriers need to be overcome en route to the tumor. Cell-mediated delivery of nanoparticles (NPs) is promising in terms of overcoming several of these barriers based on the tumoritropic migratory properties of particular cell types. This guided transport aims to enhance the NP accumulation in the tumor and moreover enhance the infiltration of regions that are typically inaccessible for free NPs. Within this study, cytotoxic CD8(+) T cells were selected as carriers based on both their ability to migrate to the tumor and their intrinsic cytolytic activity against tumor cells. Many anti-cancer nanomedicines require tumor cell internalization to mediate cytosolic drug delivery and enhance the anti-cancer effect. This proof-of-concept therefore reports on the reversible attachment of liposomes to the surface of cytotoxic T lymphocytes via a reduction sensitive coupling. The activation status of the T cells and the liposome composition are shown to strongly influence the loading efficiency. Loading the cells with liposomes does not compromise T cell functionalities like proliferation and cytolytic function. Additionally, the triggered liposome release is demonstrated upon the addition of glutathione. Based on this optimization using liposomes as model NPs, a small interfering RNA (siRNA)-loaded NP was developed that can be coupled to the surface of CD8(+) T cells.

  13. Syntaxin 8 is required for efficient lytic granule trafficking in cytotoxic T lymphocytes.

    PubMed

    Bhat, Shruthi S; Friedmann, Kim S; Knörck, Arne; Hoxha, Cora; Leidinger, Petra; Backes, Christina; Meese, Eckart; Keller, Andreas; Rettig, Jens; Hoth, Markus; Qu, Bin; Schwarz, Eva C

    2016-07-01

    Cytotoxic T lymphocytes (CTL) eliminate pathogen-infected and cancerous cells mainly by polarized secretion of lytic granules (LG, containing cytotoxic molecules like perforin and granzymes) at the immunological synapse (IS). Members of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) family are involved in trafficking (generation, transport and fusion) of vesicles at the IS. Syntaxin 8 (Stx8) is expressed in LG and colocalizes with the T cell receptor (TCR) upon IS formation. Here, we report the significance of Stx8 for human CTL cytotoxicity. We found that Stx8 mostly localized in late, recycling endosomal and lysosomal compartments with little expression in early endosomal compartments. Down-regulation of Stx8 by siRNA resulted in reduced cytotoxicity. We found that following perforin release of the pre-existing pool upon target cell contact, Stx8 down-regulated CTL regenerate perforin pools less efficiently and thus release less perforin compared to control CTL. CD107a degranulation, real-time and end-point population cytotoxicity assays, and high resolution microscopy support our conclusion that Stx8 is required for proper and timely sorting and trafficking of cytotoxic molecules to functional LG through the endosomal pathway in human CTL.

  14. Mass spectrometric identification of a naturally processed melanoma peptide recognized by CD8+ cytotoxic T lymphocytes

    PubMed Central

    1995-01-01

    We and others have previously reported that melanoma-specific, cytotoxic T lymphocytes (CTL) define a minimum of six class I-presented peptide epitopes common to most HLA-A2+ melanomas. Here we show that three of these peptide epitopes are coordinately recognized by a CTL clone obtained by limiting dilution from the peripheral blood of an HLA- A2+ melanoma patient. Tandem mass spectrometry was used to characterize and sequence one of these three naturally processed melanoma peptides. One of the potential forms of the deduced peptide sequence (XXTVXXGVX, X = I or L) matches positions 32-40 of the recently identified melanoma gene MART-1/Melan-A. This peptide (p939; ILTVILGVL) binds to HLA-A2 with an intermediate-to-low affinity and is capable of sensitizing the HLA-A2+ T2 cell line to lysis by CTL lines and clones derived from five different melanoma patients. A relative high frequency of anti-p939- specific effector cells appear to be present in situ in HLA-A2+ melanoma patients, since p939 is also recognized by freshly isolated tumor infiltrating lymphocytes. p939 represents a good candidate for the development of peptide-based immunotherapies for the treatment of patients with melanoma. PMID:7807017

  15. Evolution of viral life-cycle in response to cytotoxic T lymphocyte-mediated immunity.

    PubMed

    Louzoun, Yoram; Ganusov, Vitaly V

    2012-10-01

    Viruses in mammals are constantly faced with the problem of elimination by the host immunity. Cytotoxic T lymphocyte (CTL) responses are thought to play a major role in the control and clearance of several viral infections in mice and humans. It is therefore expected that over evolutionary time, viruses would be forced to evolve to avoid recognition by CTLs. Indeed, a number of studies have documented the accumulation of viral variants with escape mutations. These mutations allow viruses to hide from CTL responses common in the host population. CTLs recognize viruses by short protein sequences, named epitopes, derived from viral proteins. The efficiency of viral recognition by epitope-specific CTL responses depends on the expression pattern of the proteins carrying these epitopes, and the total amount of that protein (and thus epitopes) in the cell. When a virus replicates in a cell, some viral genes are expressed early in the life cycle of the virus, while other proteins are expressed late. For example, HIV infected cells first express Rev and Tat proteins, and the Gag proteins are expressed late. Here we propose a dynamical model of the viral life cycle to study how expression level of early vs. late genes may affect viral dynamics within the host and virus transmission over the course of infection. We find that for acute and chronic viral infections lower expression of early genes than that of the late genes is expected to give selective advantage and higher transmission to viruses.

  16. Syntaxin 8 is required for efficient lytic granule trafficking in cytotoxic T lymphocytes.

    PubMed

    Bhat, Shruthi S; Friedmann, Kim S; Knörck, Arne; Hoxha, Cora; Leidinger, Petra; Backes, Christina; Meese, Eckart; Keller, Andreas; Rettig, Jens; Hoth, Markus; Qu, Bin; Schwarz, Eva C

    2016-07-01

    Cytotoxic T lymphocytes (CTL) eliminate pathogen-infected and cancerous cells mainly by polarized secretion of lytic granules (LG, containing cytotoxic molecules like perforin and granzymes) at the immunological synapse (IS). Members of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) family are involved in trafficking (generation, transport and fusion) of vesicles at the IS. Syntaxin 8 (Stx8) is expressed in LG and colocalizes with the T cell receptor (TCR) upon IS formation. Here, we report the significance of Stx8 for human CTL cytotoxicity. We found that Stx8 mostly localized in late, recycling endosomal and lysosomal compartments with little expression in early endosomal compartments. Down-regulation of Stx8 by siRNA resulted in reduced cytotoxicity. We found that following perforin release of the pre-existing pool upon target cell contact, Stx8 down-regulated CTL regenerate perforin pools less efficiently and thus release less perforin compared to control CTL. CD107a degranulation, real-time and end-point population cytotoxicity assays, and high resolution microscopy support our conclusion that Stx8 is required for proper and timely sorting and trafficking of cytotoxic molecules to functional LG through the endosomal pathway in human CTL. PMID:27094127

  17. Visualization of antigen-specific human cytotoxic T lymphocytes labeled with superparamagnetic iron-oxide particles.

    PubMed

    Beer, Ambros J; Holzapfel, Konstantin; Neudorfer, Juliana; Piontek, Guido; Settles, Marcus; Krönig, Holger; Peschel, Christian; Schlegel, Jürgen; Rummeny, Ernst J; Bernhard, Helga

    2008-06-01

    New technologies are needed to characterize the migration and survival of antigen-specific T cells in vivo. In this study, we developed a novel technique for the labeling of human cytotoxic T lymphocytes with superparamagnetic iron-oxide particles and the subsequent depiction with a conventional 1.5-T magnetic resonance scanner. Antigen-specific CD8(+) T lymphocytes were labeled with ferucarbotran by lipofection. The uptake of ferucarbotran was confirmed by immunofluorescence microscopy using a dextran-specific antibody, and the intracellular enrichment of iron was measured by atomic absorption spectrometry. The imaging of T cells was performed by magnetic resonance on day 0, 2, 7 and 14 after the labeling procedure. On day 0 and 2 post labeling, a pronounced shortening of T2*-relaxation times was observed, which diminished after 7 days and was not detectable anymore after 14 days, probably due to the retained mitotic activity of the labeled T cells. Of importance, the antigen-specific cytolytic activity of the T cells was preserved following ferucarbotran labeling. Efficient ferucarbotran labeling of functionally active T lymphocytes and their detection by magnetic resonance imaging allows the in vivo monitoring of T cells and, subsequently, will impact the further development of T cell-based therapies. PMID:18286290

  18. Identification of novel myeloma-specific XBP1 peptides able to generate cytotoxic T lymphocytes: a potential therapeutic application in multiple myeloma.

    PubMed

    Bae, J; Carrasco, R; Lee, A-H; Prabhala, R; Tai, Y-T; Anderson, K C; Munshi, N C

    2011-10-01

    The purpose of these studies was to identify human leukocyte antigen (HLA)-A2(+) immunogenic peptides derived from XBP1 antigens to induce a multiple myeloma (MM)-specific immune response. Six native peptides from non-spliced XBP1 antigen and three native peptides from spliced XBP1 antigen were selected and evaluated for their HLA-A2 specificity. Among them, XBP1(184-192), XBP1 SP(196-204) and XBP1 SP(367-375) peptides showed the highest level of binding affinity, but not stability to HLA-A2 molecules. Novel heteroclitic XBP1 peptides, YISPWILAV or YLFPQLISV, demonstrated a significant improvement in HLA-A2 stability from their native XBP1(184-192) or XBP1 SP(367-375) peptide, respectively. Cytotoxic T lymphocytes generated by repeated stimulation of CD3(+) T cells with each HLA-A2-specific heteroclitic peptide showed an increased percentage of CD8(+) (cytotoxic) and CD69(+)/CD45RO(+) (activated memory) T cells and a lower percentage of CD4(+) (helper) and CD45RA(+)/CCR7(+) (naïve) T cells, which were distinct from the control T cells. Functionally, the cytotoxic T lymphocytes (CTL) demonstrated MM-specific and HLA-A2-restricted proliferation, interferon-γ secretion and cytotoxic activity in response to MM cell lines and importantly, cytotoxicity against primary MM cells. These data demonstrate the distinct immunogenic characteristics of unique heteroclitic XBP1 peptides, which induce MM-specific CTLs and highlights their potential application for immunotherapy to treat the patients with MM or its pre-malignant condition. PMID:21660045

  19. Breast and ovarian cancer-specific cytotoxic T lymphocytes recognize the same HER2/neu-derived peptide.

    PubMed Central

    Peoples, G E; Goedegebuure, P S; Smith, R; Linehan, D C; Yoshino, I; Eberlein, T J

    1995-01-01

    The identification of antigenic peptides presented on the tumor cell surface by HLA class I molecules and recognized by tumor-specific cytotoxic T lymphocytes may lead to a peptide vaccine capable of inducing protective cellular immunity. We demonstrate that both HLA-A2-restricted breast and ovarian tumor-specific cytotoxic T lymphocytes recognize shared antigenic peptides. At least one of these peptides is derived from the oncogene product of HER2/neu, which is overexpressed in 30-40% of all breast and ovarian cancers. T cells sensitized against this nine-amino acid sequence demonstrate significant recognition of HLA-A2+, HER2/neu+ tumors. Since 50% of the tumor-cell population is HLA-A2+ and many different tumors express HER2/neu, this peptide may be widely recognized and have many clinical applications. PMID:7831305

  20. Designing and testing broadly-protective filoviral vaccines optimized for cytotoxic T-lymphocyte epitope coverage.

    PubMed

    Fenimore, Paul W; Muhammad, Majidat A; Fischer, William M; Foley, Brian T; Bakken, Russell R; Thurmond, James R; Yusim, Karina; Yoon, Hyejin; Parker, Michael; Hart, Mary Kate; Dye, John M; Korber, Bette; Kuiken, Carla

    2012-01-01

    We report the rational design and in vivo testing of mosaic proteins for a polyvalent pan-filoviral vaccine using a computational strategy designed for the Human Immunodeficiency Virus type 1 (HIV-1) but also appropriate for Hepatitis C virus (HCV) and potentially other diverse viruses. Mosaics are sets of artificial recombinant proteins that are based on natural proteins. The recombinants are computationally selected using a genetic algorithm to optimize the coverage of potential cytotoxic T lymphocyte (CTL) epitopes. Because evolutionary history differs markedly between HIV-1 and filoviruses, we devised an adapted computational technique that is effective for sparsely sampled taxa; our first significant result is that the mosaic technique is effective in creating high-quality mosaic filovirus proteins. The resulting coverage of potential epitopes across filovirus species is superior to coverage by any natural variants, including current vaccine strains with demonstrated cross-reactivity. The mosaic cocktails are also robust: mosaics substantially outperformed natural strains when computationally tested against poorly sampled species and more variable genes. Furthermore, in a computational comparison of cross-reactive potential a design constructed prior to the Bundibugyo outbreak performed nearly as well against all species as an updated design that included Bundibugyo. These points suggest that the mosaic designs would be more resilient than natural-variant vaccines against future Ebola outbreaks dominated by novel viral variants. We demonstrate in vivo immunogenicity and protection against a heterologous challenge in a mouse model. This design work delineates the likely requirements and limitations on broadly-protective filoviral CTL vaccines.

  1. IFN-γ mediates graft-versus-breast cancer effects via enhancing cytotoxic T lymphocyte activity.

    PubMed

    Zhao, Qianjie; Tong, Lingling; He, Ningning; Feng, Guowei; Leng, Liang; Sun, Weijun; Xu, Yang; Wang, Yuebing; Xiang, Rong; Li, Zongjin

    2014-08-01

    Previous studies have demonstrated the beneficial effect of graft-versus-tumor (GVT) following hematopoietic stem cell transplantation (HSCT) on the incidence of leukemia relapse and the overall survival rate of patients with leukemia; however, detailed mechanisms underlying the effects GVT exhibits on solid tumors following allogeneic HSCT are yet to be elucidated. The aim of the present study was to investigate the immune mechanism underlying the effect of interferon (IFN)-γ on GVT following allogeneic HSCT in breast cancer therapy. An in situ breast cancer mouse model was established by injecting 5×10(4) 4T1 cells into the mammary fat pads of BALB/c mice. The 4T1 cells were transfected with the firefly luciferase reporter gene in order to monitor the tumor progression in real time. An allogeneic HSCT model was then established by transplanting bone marrow mononuclear cells from C57BL/6 mice to the BALB/c mice. To investigate the influence of T lymphocyte proliferation following allogeneic bone marrow transplantation, the levels of CD3(+)CD8(+) cytotoxic T lymphocytes (CTLs) and CD4(+)CD25(+) regulatory T cells were determined. In addition, IFN-γ and granzyme B expression levels in splenic lymphocytes were analyzed using flow cytometry. Allogeneic HSCT was found to significantly promote the proliferation and cytotoxicity of CTLs and suppress the growth of breast cancer. Furthermore, the secretory levels of IFN-γ and granzyme B by T cells were elevated following allogeneic HSCT. These results indicated that alloreactive T cells increased the secretion of IFN-γ, which promoted the alloresponse of donor CTLs. In addition, the CTLs produced granzyme B, which exerted a tumor suppressive effect. PMID:25009582

  2. Efficient lysis of human immunodeficiency virus type 1-infected cells by cytotoxic T lymphocytes.

    PubMed

    Yang, O O; Kalams, S A; Rosenzweig, M; Trocha, A; Jones, N; Koziel, M; Walker, B D; Johnson, R P

    1996-09-01

    Numerous studies of human immunodeficiency virus type 1 (HIV-1)-specific cytotoxic T lymphocytes (CTL) have examined their ability to recognize B-cell lines expressing recombinant HIV-1 proteins, but relatively few data regarding the lysis of HIV-1-infected cells by CTL are available. We studied the ability of HIV-1-specific CTL clones of defined epitope specificity and HLA restriction to lyse infected CD4+ cells at serial time points following infection. CD4+ cell lines were acutely infected with HIV-1 IIIB at a high multiplicity of infection, and the kinetics of cell lysis were examined and compared with the kinetics of viral replication. Intracellular HIV-1 p24 expression was detected by 1 to 2 days after infection, reaching over 98% positive cells by day 4. Recognition of the infected cells by HLA A2- and B14-restricted CTL clones closely paralleled intracellular p24 expression and preceded peak virion production. The maximal levels of lysis with Gag-, reverse transcriptase-, and envelope-specific clones were different, however. The Gag- and envelope-specific clones lysed infected cells at levels equivalent to peptide-sensitized controls, whereas lysis by the reverse transcriptase-specific clones plateaued at a lower level. Peptide titration curves indicated that this effect was not due to differences in sensitivity to the cognate epitopes for the different clones. Although HIV-1 infection induced an approximately 50% decrease in class I HLA expression on the surface of infected cells, lysis by CTL clones was unaffected. These studies indicate that HIV-1-specific CTL can efficiently lyse HIV-1-infected CD4+ cells and suggest that the partial downregulation of class I molecules in infected cells does not significantly affect recognition by CTL.

  3. Serglycin determines secretory granule repertoire and regulates natural killer cell and cytotoxic T lymphocyte cytotoxicity.

    PubMed

    Sutton, Vivien R; Brennan, Amelia J; Ellis, Sarah; Danne, Jill; Thia, Kevin; Jenkins, Misty R; Voskoboinik, Ilia; Pejler, Gunnar; Johnstone, Ricky W; Andrews, Daniel M; Trapani, Joseph A

    2016-03-01

    The anionic proteoglycan serglycin is a major constituent of secretory granules in cytotoxic T lymphocyte (CTL)/natural killer (NK) cells, and is proposed to promote the safe storage of the mostly cationic granule toxins, granzymes and perforin. Despite the extensive defects of mast cell function reported in serglycin gene-disrupted mice, no comprehensive study of physiologically relevant CTL/NK cell populations has been reported. We show that the cytotoxicity of serglycin-deficient CTL and NK cells is severely compromised but can be partly compensated in both cell types when they become activated. Reduced intracellular granzyme B levels were noted, particularly in CD27(+) CD11b(+) mature NK cells, whereas serglycin(-/-) TCR-transgenic (OTI) CD8 T cells also had reduced perforin stores. Culture supernatants from serglycin(-/-) OTI T cells and interleukin-2-activated NK contained increased granzyme B, linking reduced storage with heightened export. By contrast, granzyme A was not significantly reduced in cells lacking serglycin, indicating differentially regulated trafficking and/or storage for the two granzymes. A quantitative analysis of different granule classes by transmission electronmicroscopy showed a selective loss of dense-core granules in serglycin(-/-) CD8(+) CTLs, although other granule types were maintained quantitatively. The findings of the present study show that serglycin plays a critical role in the maturation of dense-core cytotoxic granules in cytotoxic lymphocytes and the trafficking and storage of perforin and granzyme B, whereas granzyme A is unaffected. The skewed retention of cytotoxic effector molecules markedly reduces CTL/NK cell cytotoxicity, although this is partly compensated for as a result of activating the cells by physiological means.

  4. Manipulation of regulatory T cells and antigen-specific cytotoxic T lymphocyte-based tumour immunotherapy

    PubMed Central

    Karimi, Shirin; Chattopadhyay, Subhasis; Chakraborty, Nitya G

    2015-01-01

    The most potent killing machinery in our immune system is the cytotoxic T lymphocyte (CTL). Since the possibility for self-destruction by these cells is high, many regulatory activities exist to prevent autoimmune destruction by these cells. A tumour (cancer) grows from the cells of the body and is tolerated by the body's immune system. Yet, it has been possible to generate tumour-associated antigen (TAA) -specific CTL that are also self-antigen specific in vivo, to achieve a degree of therapeutic efficacy. Tumour-associated antigen-specific T-cell tolerance through pathways of self-tolerance generation represents a significant challenge to successful immunotherapy. CD4+ CD25+ FoxP3+ T cells, referred to as T regulatory (Treg) cells, are selected in the thymus as controllers of the anti-self repertoire. These cells are referred to as natural T regulatory (nTreg) cells. According to the new consensus (Nature Immunology 2013; 14:307–308) these cells are to be termed as (tTreg). There is another class of CD4+ Treg cells also involved in regulatory function in the periphery, also phenotypically CD4+ CD25±, classified as induced Treg (iTreg) cells. These cells are to be termed as peripherally induced Treg (pTreg) cells. In vitro-induced Treg cells with suppressor function should be termed as iTreg. These different Treg cells differ in their requirements for activation and in their mode of action. The current challenges are to determine the degree of specificity of these Treg cells in recognizing the same TAA as the CTL population and to circumvent their regulatory constraints so as to achieve robust CTL responses against cancer. PMID:25243729

  5. Increased lung epithelial permeability in HIV-infected patients with isolated cytotoxic T-lymphocytic alveolitis

    SciTech Connect

    Meignan, M.; Guillon, J.M.; Denis, M.; Joly, P.; Rosso, J.; Carette, M.F.; Baud, L.; Parquin, F.; Plata, F.; Debre, P. )

    1990-05-01

    HIV-related lymphocytic alveolitis is common in HIV-seropositive patients without lung infection or tumor. In some of them a fraction of alveolar lymphocytes are HIV-specific cytotoxic T-lymphocytes (CTL) bearing the CD8 and D44 cell surface markers and capable of killing HIV-infected alveolar macrophages. In order to evaluate the in vivo effect of these CTL on lung function, we measured the pulmonary clearance of aerosolized 99mTc-diethylene triamine penta-acetate (DTPA-CI) on 24 occasions in 22 patients with lymphocytic alveolitis. DTPA-CI has been selected as a highly sensitive test to detect injury of the lung epithelium. In 13 of the patients, we found a high DTPA-CI of 4.56 +/- 2.54%.min-1 (mean +/- SD), suggesting an increase of the epithelial permeability. The lymphocytic alveolitis was then characterized by a high cellularity, a high proportion of lymphocytes (59 +/- 18%), mainly composed of CD8+D44+ T-lymphocytes (149 +/- 109 cells/mm3), which spontaneously exhibited a cytolytic activity against the autologous alveolar macrophages in a standard 51Cr release assay. In the remaining 11 patients, DTPA-CI was normal (less than 1.78%.min-1), lymphocytic alveolitis being characterized by a low number or an absence of CD8+D44+ alveolar lymphocytes (9 +/- 13 cells/mm3) with no significant cytolytic activity. In the whole group, a significant correlation (r = 0.74, p = 0.0004) was found between the DTPA-CI and the number of CD8+D44+ lymphocytes and their cytotoxic activity against alveolar macrophages. Altogether, these results suggest that an injury of the lung epithelium could result from a HIV-specific CTL-induced immunologic conflict.

  6. Mathematical modeling of escape of HIV from cytotoxic T lymphocyte responses

    NASA Astrophysics Data System (ADS)

    Ganusov, Vitaly V.; Neher, Richard A.; Perelson, Alan S.

    2013-01-01

    Human immunodeficiency virus (HIV-1 or simply HIV) induces a persistent infection, which in the absence of treatment leads to AIDS and death in almost all infected individuals. HIV infection elicits a vigorous immune response starting about 2-3 weeks postinfection that can lower the amount of virus in the body, but which cannot eradicate the virus. How HIV establishes a chronic infection in the face of a strong immune response remains poorly understood. It has been shown that HIV is able to rapidly change its proteins via mutation to evade recognition by virus-specific cytotoxic T lymphocytes (CTLs). Typically, an HIV-infected patient will generate 4-12 CTL responses specific for parts of viral proteins called epitopes. Such CTL responses lead to strong selective pressure to change the viral sequences encoding these epitopes so as to avoid CTL recognition. Indeed, the viral population ‘escapes’ from about half of the CTL responses by mutation in the first year. Here we review experimental data on HIV evolution in response to CTL pressure, mathematical models developed to explain this evolution, and highlight problems associated with the data and previous modeling efforts. We show that estimates of the strength of the epitope-specific CTL response depend on the method used to fit models to experimental data and on the assumptions made regarding how mutants are generated during infection. We illustrate that allowing CTL responses to decay over time may improve the model fit to experimental data and provides higher estimates of the killing efficacy of HIV-specific CTLs. We also propose a novel method for simultaneously estimating the killing efficacy of multiple CTL populations specific for different epitopes of HIV using stochastic simulations. Lastly, we show that current estimates of the efficacy at which HIV-specific CTLs clear virus-infected cells can be improved by more frequent sampling of viral sequences and by combining data on sequence evolution with

  7. Behavior and Properties of Mature Lytic Granules at the Immunological Synapse of Human Cytotoxic T Lymphocytes

    PubMed Central

    Ming, Min; Schirra, Claudia; Becherer, Ute; Stevens, David R.; Rettig, Jens

    2015-01-01

    Killing of virally infected cells or tumor cells by cytotoxic T lymphocytes requires targeting of lytic granules to the junction between the CTL and its target. We used whole-cell patch clamp to measure the cell capacitance at fixed intracellular [Ca2+] to study fusion of lytic granules in human CTLs. Expression of a fluorescently labeled human granzyme B construct allowed identification of lytic granule fusion using total internal reflection fluorescence microscopy. In this way capacitance steps due to lytic granule fusion were identified. Our goal was to determine the size of fusing lytic granules and to describe their behavior at the plasma membrane. On average, 5.02 ± 3.09 (mean ± s.d.) lytic granules were released per CTL. The amplitude of lytic granule fusion events was ~ 3.3 fF consistent with a diameter of about 325 nm. Fusion latency was biphasic with time constants of 15.9 and 106 seconds. The dwell time of fusing lytic granules was exponentially distributed with a mean dwell time of 28.5 seconds. Fusion ended in spite of the continued presence of granules at the immune synapse. The mobility of fusing granules at the membrane was indistinguishable from that of lytic granules which failed to fuse. While dwelling at the plasma membrane lytic granules exhibit mobility consistent with docking interspersed with short periods of greater mobility. The failure of lytic granules to fuse when visible in TIRF at the membrane may indicate that a membrane-confined reaction is rate limiting. PMID:26296096

  8. A Pilot Study on Cytotoxic T Lymphocyte-4 Gene Polymorphisms in Urinary Schistosomiasis

    PubMed Central

    Idris, Zulkarnain Md; Yazdanbakhsh, Maria; Adegnika, Ayola Akim; Lell, Bertrand; Issifou, Saadou

    2012-01-01

    Urinary schistosomiasis is caused by the digenetic trematode Schistosoma haematobium, characterized by accumulation of eggs in the genitourinary tract. Cytotoxic T-lymphocyte antigen 4 (CTLA-4) can play an important role in parasitic infection due to its major role as a negative regulator of T-cell activation and proliferation. This study was performed in patients with schistosomiasis and healthy controls to analyze the allele and genotype frequencies of four CTLA-4 gene polymorphisms. The CTLA-4 gene was amplified using Taqman real-time polymerase chain reaction, and allele and genotypes of 49 patients with schistosomiasis were analyzed using allelic discrimination analysis followed by subsequent direct sequencing. The results were compared with healthy control subjects. The frequencies of CTLA-4 rs733618 A allele at position −1722 (p=0.001), rs11571316 C allele at position −1577 (p<0.001), and rs231775 A allele at position +49 (p=0.002) in the patient group were significantly higher than the control group. The rs733618 AA genotype (p=0.001), rs11571316 CC genotype (p<0.001), and rs231775 AA genotype (p=0.007) were also significantly overrepresented. Meanwhile, rs733618 AG genotype (p=0.001), rs11571316 CT genotype (p=0.02), and rs231775 GG genotype (p=0.029) were significantly decreased in the patients with schistosomiasis, as compared with the controls. No significant difference was observed in both allele and genotype of rs16841252. The results of this study suggest that the rs733618, rs11571316, and rs231775 polymorphisms in the CTLA-4 gene may influence susceptibility to schistosomiasis infection in the Gabonese children. PMID:22288822

  9. Detection of Cytotoxic T-Lymphocyte Associated Antigen-4 Gene Polymorphism in Type 1 Diabetes Mellitus.

    PubMed

    Arafa, Roshdan M; Desouky, Somaya M; Emam, Sherin M; Abed, Neveen Tawfik; Mohamed, Sahar Y

    2015-01-01

    Type 1 diabetes is one of the most common chronic childhood illnesses. Interplay between genetic susceptibility and environmental factors is thought to provide the fundamental element for the disease. It has been shown that more than 40 genetic loci are associated with T1DM. Important one among these is the CTLA-4. This work aimed to detect Cytotoxic T Lymphocyte-associated antigen 4 (CTLA-4) gene polymorphism in patients with type 1 diabetes mellitus T1DM using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to clarify its role in the susceptibility to T1DM. The study was carried out on forty unrelated Egyptian children with TIDM. Twenty unrelated healthy children were enrolled as a control group. Blood samples were collected from patients and control groups and subjected to CTLA-4 gene polymorphism analysis using polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP). CTLA-4 G allele and GG homozygous genotype were significantly increased in T1DM patients than in control group (P < 0.001, P = 0.002 respectively). There was significant association between the three CTLA-4 genotypes (AA, AG, GG) and diabetic complications (p = 0.002), AG and GG polymorphisms were associated with complications of diabetes with ratio 84.6% and 100% respectively. While no association was found with sex, weight, height, risk factors of diabetes or insulin treatment. It was concluded that there is a strong association between AG polymorphism and T1DM (P = 0.002). PMID:26415372

  10. Infection of lymphocytes by a virus that aborts cytotoxic T lymphocyte activity and establishes persistent infection

    PubMed Central

    1991-01-01

    For viruses to establish persistent infections in their hosts, they must possess some mechanism for evading clearance by the immune system. When inoculated into adult immunocompetent mice, wild-type lymphocytic choriomeningitis virus (LCMV ARM) induces a CD8(+)-mediated cytotoxic T lymphocyte (CTL) response that clears the infection within 7-14 d (CTL+ [P-]). By contrast, variant viruses isolated from lymphoid tissues of persistently infected mice fail to induce a CTL response and are thus able to establish a persistent infection in adult mice (CTL- [P+]). This report compares the interaction of CTL+ (P-) and CTL- (P+) viruses with cells of the immune system. Both types of virus initially bind to 2-4% of CD4+ and CD8+ T lymphocytes and replicate within cells of both subsets. The replication of CTL- (P+) and CTL+ (P-) viruses in lymphocytes in vivo is similar for the first 5 d after initiating infection. Thereafter, in mice infected with CTL- (P+) variants, lymphocytes retain viral genetic information, and infectious virus can be recovered throughout the animals' lives. In contrast, when adult mice are infected with wild-type CTL+ (P-) LCMV ARM, virus is not recovered from lymphocytes for greater than 7 d after infection. A CD8(+)-mediated anti-LCMV CTL response is induced in such mice. Clearance of infected lymphocytes is produced by these LCMV-specific CTLs, as shown by their ability to lyse lymphocytes expressing LCMV determinants in vitro and the fact that depletion of CD8+ lymphocytes before infection with CTL+ (P-) viruses results in levels of infected lymphocytes similar to those found in undepleted CTL- (P+)-infected mice. Hence, CTL-mediated lysis of T lymphocytes carrying infectious virus is a critical factor determining whether virus persists or the infection is terminated. PMID:1905339

  11. Adoptive transfer of cytotoxic T lymphocytes targeting two different antigens limits antigen loss and tumor escape.

    PubMed

    Kaluza, Karen M; Kottke, Timothy; Diaz, Rosa Maria; Rommelfanger, Diana; Thompson, Jill; Vile, Richard

    2012-10-01

    An antitumor T-cell response can lead to tumor control without clearing all tumor cells. As long as residual tumor cells remain, there is a constant risk of escape from that T-cell response. We previously showed that adoptive transfer of anti-ova OT-I T cells into B16ova-bearing mice led to tumor regression followed by escape of tumors that had lost the ova gene, rendering the OT-I T cells ineffective. In this study, we hypothesized that simultaneous transfer of cytotoxic T lymphocytes targeted against two independent antigens would reduce selection for single-antigen-loss cells, thereby limiting tumor escape. Using OT-I and Pmel T cells to treat B16ova tumors, we found that early cotransfer could prevent tumor emergence in most mice, whereas neither T-cell specificity alone was able to do so. When combined with total body irradiation for the treatment of larger 7-day tumors, cotransfer was also better at limiting tumor recurrence, and the tumors that did escape combination therapy continued to express both target antigens. As adoptively transferred T cells also persisted in vivo, even in mice with recurrent tumors, we hypothesized that restimulation of these antitumor T cells would prolong survival of mice with recurrent tumors. Consistent with this hypothesis, administration of a low-dose regimen of cyclophosphamide following tumor escape slowed tumor growth in mice that had previously received T-cell therapy, but not in control-treated mice, an effect that was associated with increased activation of T cells in vitro by low- but not high-dose cyclophosphamide.

  12. Longitudinal analysis of feline leukemia virus-specific cytotoxic T lymphocytes: correlation with recovery from infection.

    PubMed

    Flynn, J Norman; Dunham, Stephen P; Watson, Vivien; Jarrett, Oswald

    2002-03-01

    Feline leukemia virus (FeLV) is a common naturally occurring gammaretrovirus of domestic cats that is associated with degenerative diseases of the hematopoietic system, immunodeficiency, and neoplasia. Although the majority of cats exposed to FeLV develop a transient infection and recover, a proportion of cats become persistently viremic and many subsequently develop fatal diseases. To define the dominant host immune effector mechanisms responsible for the outcome of infection, we studied the longitudinal changes in FeLV-specific cytotoxic T lymphocytes (CTLs) in a group of naïve cats following oronasal exposure to FeLV. Using (51)Cr release assays to measure ex vivo virus-specific cytotoxicity, the emerging virus-specific CTL response was correlated with modulations in viral burden as assessed by detection of infectious virus, FeLV p27 capsid antigen, and proviral DNA in the blood. High levels of circulating FeLV-specific effector CTLs appeared before virus neutralizing antibodies in cats that recovered from exposure to FeLV. In contrast, persistent viremia was associated with a silencing of virus-specific humoral and cell-mediated host immune effector mechanisms. A single transfer of between 2 x 10(7) and 1 x 10(8) autologous, antigen-activated lymphoblasts was associated with a downmodulation in viral burden in vivo. The results suggest an important role for FeLV-specific CTLs in retroviral immunity and demonstrate the potential to modulate disease outcome by the adoptive transfer of antigen-specific T cells in vivo.

  13. Correlation between CD8 dependency and determinant density using peptide-induced, Ld-restricted cytotoxic T lymphocytes.

    PubMed

    Alexander, M A; Damico, C A; Wieties, K M; Hansen, T H; Connolly, J M

    1991-04-01

    We have taken advantage of some unique properties of H-2Ld to investigate the determinant density requirements for cytotoxic T lymphocyte (CTL) priming versus effector function and to correlate the determinant density requirements with CD8 dependency. In a previous study (Lie, W.-R., N. B. Myers, J. Gorka, R. J. Rubocki, J. M. Connolly, and T. H. Hansen. 1990. Nature [Lond.]. 344:439), we demonstrated that culturing normal cells with peptides known to be restricted by H-2Ld led to a two- to fourfold increase in surface Ld expression. In the present study, we demonstrate the generation of Ld-restricted, peptide-specific in vitro primary CTL by culturing spleen cells with murine cytomegalovirus or tum- peptide at concentrations previously shown to result in maximum induction of Ld expression. Target cells can be sensitized for recognition by these CTL with lower dose of peptide than are required for the primary sensitization. This demonstrates differences in the determinant density requirements for priming versus effector function. The in vitro primary CTL generated with peptide can weakly lyse target cells that express the determinant endogenously, and CTL lines and clones capable of strong lysis of endogenous expressors are easily obtained. In both cases, target cells treated with exogenous peptide are lysed better than target cells expressing antigen endogenously. This suggested that there are differences in the determinant density of peptide-fed versus endogenous targets. This interpretation was substantiated when it was observed that the level of lysis of target cells expressing endogenous determinants correlated inversely with the amount of peptide required to sensitize targets for recognition by various tum- -specific CTL clones. Furthermore, simultaneous titration of both the peptide used to treat target cells and the antibody to CD8 revealed that the various CTL clones analyzed displayed widely disparate CD8 dependencies. In each case, the CD8 dependency

  14. The cytotoxic T lymphocyte response to multiple hepatitis B virus polymerase epitopes during and after acute viral hepatitis

    PubMed Central

    1995-01-01

    Cytotoxic T lymphocytes (CTL) are thought to contribute to viral clearance and liver cell injury during hepatitis B virus (HBV) infection. Using a strategy involving the in vitro stimulation of peripheral blood mononuclear cells (PBMC) with HBV-derived synthetic peptides containing HLA-A2.1, -A31, and -Aw68 binding motifs, we have previously described CTL responses to several epitopes within the HBV nucleocapsid and envelope antigens in patients with acute hepatitis. In this study we define six HLA-A2-restricted CTL epitopes located in the highly conserved reverse transcriptase and RNase H domains of the viral polymerase protein, and we show that the CTL response to polymerase is polyclonal, multispecific, and mediated by CD8+ T cells in patients with acute viral hepatitis, but that it is not detectable in patients with chronic HBV infection or uninfected healthy blood donors. Importantly, the peptide-activated CTL recognize target cells that express endogenously synthesized polymerase protein, suggesting that these peptides represent naturally processed viral epitopes. DNA sequence analysis of the viruses in patients who did not respond to peptide stimulation indicated that CTL nonresponsiveness was not due to infection by viral variants that differed in sequences from the synthetic peptides. CTL specific for one of the epitopes were unable to recognize several naturally occurring viral variants, except at high peptide concentration, underlining the HBV subtype specificity of this response. Furthermore, CTL responses against polymerase, core, and envelope epitopes were detectable for more than a year after complete clinical recovery and seroconversion, reflecting either the persistence of trace amounts of virus or the presence of long lived memory CTL in the absence of viral antigen. Finally, we demonstrated that wild type viral DNA and RNA can persist indefinitely, in trace quantities, in the serum and PBMC after complete clinical and serological recovery

  15. Prospective study of cytotoxic T lymphocyte responses to influenza and antibodies to human T lymphotropic virus-III in homosexual men. Selective loss of an influenza-specific, human leukocyte antigen-restricted cytotoxic T lymphocyte response in human T lymphotropic virus-III positive individuals with symptoms of acquired immunodeficiency syndrome and in a patient with acquired immunodeficiency syndrome.

    PubMed Central

    Shearer, G M; Salahuddin, S Z; Markham, P D; Joseph, L J; Payne, S M; Kriebel, P; Bernstein, D C; Biddison, W E; Sarngadharan, M G; Gallo, R C

    1985-01-01

    Peripheral blood leukocytes (PBL) from 18 homosexual men who did not have acquired immunodeficiency syndrome (AIDS) and from 9 heterosexual men were repetitively tested for their ability to generate HLA self-restricted cytotoxic T lymphocyte responses to influenza virus (flu-self) over a 2-yr period. The sera of the same donors were tested for antibodies to human T lymphotropic virus-III (HTLV-III). Six of the homosexual and none of the heterosexual donors consistently generated weak cytotoxic T lymphocyte responses to flu-self. Seven of the homosexual and none of the heterosexual donors were seropositive for antibodies to HTLV-III. No obvious correlation was detected between weak flu-self cytotoxic T lymphocyte responses and antibodies to HTLV-III. However, one homosexual donor generated no detectable cytotoxic T lymphocyte activity to flu-self, although he was a strong responder to HLA-alloantigens. This donor had an OKT4:OKT8 ratio of 0.4 and was seropositive for HTLV-III antigens; HTLV-III virus was identified in his PBL; and he developed AIDS during the course of this study. A second donor with lymphadenopathy and who was seropositive for HTLV-III antigens exhibited marginal cytotoxic T lymphocyte activity to flu-self which he subsequently lost. PBL from two patients, one with Kaposi's sarcoma and one with generalized lymphadenopathy, were also tested for cytotoxic T lymphocyte responses to flu-self and to alloantigens. Both donors failed to generate cytotoxic T lymphocyte to flu-self, but generated strong cytotoxic T lymphocyte responses to alloantigens. The selective loss of an HLA-restricted cytotoxic T lymphocyte response without loss of HLA alloantigenic cytotoxic T lymphocyte activity may be an important functional immunologic characteristic in the development of AIDS. PMID:2997287

  16. Immunization with a replication-deficient mutant of herpes simplex virus type 1 (HSV-1) induces a CD8+ cytotoxic T-lymphocyte response and confers a level of protection comparable to that of wild-type HSV-1.

    PubMed Central

    Brehm, M A; Bonneau, R H; Knipe, D M; Tevethia, S S

    1997-01-01

    Replication-deficient viruses provide an attractive alternative to conventional approaches used in the induction of antiviral immunity. We have quantitatively evaluated both the primary and memory cytotoxic T-lymphocyte (CTL) responses elicited by immunization with a replication-deficient mutant of herpes simplex virus type 1 (HSV-1). In addition, we have examined the potential role of these CTL in protection against HSV infection. Using bulk culture analysis and limiting-dilution analysis, we have shown that a replication-deficient virus, d301, generates a strong primary CTL response that is comparable to the response induced by the wild type-strain, KOS1.1. Furthermore, the CTL induced by d301 immunization recognized the immunodominant, H-2Kb-restricted, CTL recognition epitope gB498-505 to a level similar to that for CTL from KOS1.1-immunized mice. The memory CTL response evoked by d301 was strong and persistent, even though the frequencies of CTL were slightly lower than the frequencies of CTL induced by KOS1.1. Adoptive transfer studies indicated that both the CD8+ and the CD4+ T-cell responses generated by immunization with d301 and KOS1.1 were able to limit the extent of a cutaneous HSV infection to comparable levels. Overall, these results indicate that viral replication is not necessary to elicit a potent and durable HSV-specific immune response and suggest that replication-deficient viruses may be effective in eliciting protection against viral pathogens. PMID:9094625

  17. Apoptosis and expression of cytotoxic T lymphocyte effector molecules in renal allografts.

    PubMed

    Olive, C; Cheung, C; Falk, M C

    1999-03-01

    Cytotoxic T lymphocyte (CTL) mediated apoptosis is thought to play a major role in the rejection of renal allografts following transplantation, however, the CTL effector mechanism that is primarily responsible for immunological rejection is unknown. The two major effector pathways of CTL killing which lead to apoptosis involve the Fas/Fas ligand (Fas L) lytic pathway, and the perforin/granzyme degranulation pathway. The expression of CTL effector molecules which influence these pathways include Fas, Fas L and TiA-1 (cytotoxic granule protein). This study has investigated apoptosis by in situ terminal deoxytransferase-catalysed DNA nick end labelling (TUNEL), and the expression of CTL effector molecules by immunohistochemistry, in renal allograft biopsies obtained from patients following kidney transplantation. Renal biopsies were classified into three histological groups; acute cellular rejection, chronic rejection, or no rejection. The extent of T-cell infiltration of renal tissues was assessed by immunohistochemical staining with an anti-CD3 monoclonal antibody. Numerous TUNEL positive cells were detected in all transplant biopsies examined; these consisted mainly of renal tubular cells and infiltrating cells, with some TUNEL positive cells also detected in the glomeruli. In the case of normal kidney tissue, renal cells also stained positive for TUNEL but there was no lymphocytic infiltration. There was significantly more T-cell infiltration observed in acute rejection biopsies compared to the no rejection biopsies. In the case of Fas L expression, there was little expression in all three biopsy groups, apart from one case of chronic rejection. Conversely, although there were no significant differences in TiA-1 expression between the three biopsy groups, TiA-1 expression was more prominent in acute rejection biopsies. Furthermore, Fas expression was significantly decreased in acute rejection biopsies when compared to those of chronic and no rejection in which Fas

  18. Recognition of hybrid HLA molecules expressed on murine P815 cells using human alloreactive cytotoxic T lymphocytes.

    PubMed

    Healy, F; Sire, J; Kahn-Perles, B; Gomard, E; Levy, J P; Jordan, B R

    1987-01-01

    The HLA-A2 and -A3 genes were used to construct intra-exon hybrids in which part of the third exon (corresponding to the second domain) was of one type and the rest of the other. Murine P815 cells expressing these hybrid constructs were assayed with human alloreactive cytotoxic T-lymphocyte lines specific for either HLA-A2 or HLA-A3. Specific recognition patterns were obtained which indicate that, in some cases, a small portion of the HLA-A2 sequence in an HLA-A3 background is sufficient for recognition by HLA-A2-specific cytotoxic T cells. PMID:3107590

  19. Human immunodeficiency virus type 1 envelope-specific cytotoxic T lymphocytes response dynamics after prime-boost vaccine regimens with human immunodeficiency virus type 1 canarypox and pseudovirions.

    PubMed

    Arp, J; Rovinski, B; Sambhara, S; Tartaglia, J; Dekaban, G

    1999-01-01

    Virus-specific cytotoxic T lymphocytes (CTLs) may represent significant immune mechanisms in the control of human immunodeficiency virus (HIV) infection and, therefore, CTL induction may be a fundamental goal in the development of an efficacious acquired immunodeficiency syndrome (AIDS) vaccine. In the current study, prime-boost protocols were used to investigate the potential of noninfectious human immunodeficiency virus type 1 (HIV-1) pseudovirions (HIV PSV) in enhancing HIV-specific CTL responses in Balb/c mice primed with the recombinant canarypox vector, vCP205, encoding HIV-1 gp120 (MN strain) in addition to Gag/Protease (HIB strain). The prime-boost immunization regimens were administered intramuscularly and involved injections of vCP205 followed by boosts with HIV PSV. Previous vaccination strategies solely involving vCP205 had induced good cellular immune responses in uninfected human volunteers, despite some limitations. The use of genetically engineered HIV PSV was a logical step in the evaluation of whole noninfectious virus or inactivated virus vaccine strategies, particularly as a potential boosting agent for vCP205-primed recipients. Based on this current study, HIV PSV appeared to have the capability to effectively induce and boost cell-mediated HIV-1-specific responses. In order to observe the immune effects of HIV PSV in a prime-boost immunization strategy, both HIV vaccine immunogens required careful titration in vivo. This suggests that careful consideration should be given to the optimization of immunization protocols destined for human use.

  20. Stimulus-dependent triggering or inhibition of cytotoxicity in human cytotoxic T lymphocytes by activators of protein kinase C.

    PubMed Central

    Schrezenmeier, H; Kurrle, R; Fleischer, B

    1986-01-01

    The influence of activators of protein kinase C (PKC) on the delivery of the lethal hit by human cytotoxic T lymphocyte (CTL) clones was studied. In the absence of other signals, short-term incubation with two structurally unrelated activators of PKC, but not with a non-activating phorbolester, resulted in significant triggering of CTL, whereas overnight incubation with PKC activators led to reduction of cytotoxic activity. Furthermore, activation of PKC had an inhibitory effect on simultaneous triggering by anti-T3 monoclonal antibodies or by phytohaemagglutinin, but strongly enhanced the activating effect of anti-T11 antibodies. These results suggest that PKC is part of the cascade of signals transmitted within a CTL after triggering. PMID:3491782

  1. Relative dominance of Gag p24-specific cytotoxic T lymphocytes is associated with human immunodeficiency virus control.

    PubMed

    Zuñiga, Rosario; Lucchetti, Aldo; Galvan, Patricia; Sanchez, Shyla; Sanchez, Carmen; Hernandez, Ana; Sanchez, Hugo; Frahm, Nicole; Linde, Caitlyn H; Hewitt, Hannah S; Hildebrand, William; Altfeld, Marcus; Allen, Todd M; Walker, Bruce D; Korber, Bette T; Leitner, Thomas; Sanchez, Jorge; Brander, Christian

    2006-03-01

    Conflicting data on the role of total virus- and protein-specific cytotoxic-T-lymphocyte (CTL) responses in the control of human immunodeficiency virus (HIV) disease progression exist. We present data generated from a Peruvian cohort of untreated, clade B-infected subjects, demonstrating that the proportion of Gag-specific, and in particular p24-reactive, CTL responses among the total virus-specific CTL activity is associated with individuals' CD4 counts and viral loads. Analyses in a second cohort in the United States confirm these findings and point towards a dominant role of Gag-specific immunity in effective control of HIV infection, providing important guidance for HIV vaccine development. PMID:16501126

  2. Definition of an optimal cytotoxic T lymphocyte epitope in the latently expressed Kaposi's sarcoma-associated herpesvirus kaposin protein.

    PubMed

    Brander, C; O'Connor, P; Suscovich, T; Jones, N G; Lee, Y; Kedes, D; Ganem, D; Martin, J; Osmond, D; Southwood, S; Sette, A; Walker, B D; Scadden, D T

    2001-07-15

    Cytotoxic T lymphocytes (CTL) recognize and kill virus-infected cells and contribute to immunologic control of viral replication. For many herpesviruses (e.g., Epstein-Barr and cytomegalovirus), virus-specific CTL responses can be readily detected in infected persons, but CTL responses against Kaposi's sarcoma-associated herpesvirus (KSHV) appear to be weak and remain poorly characterized. Using a human leukocyte antigen (HLA) binding motif-based epitope prediction algorithm, we identified 37 HLA-A*0201 binding peptides from 8 KSHV open-reading frames (ORFs). After in vitro stimulation of peripheral blood mononuclear cells from KSHV-infected persons, CTL responses against 1 peptide in the KSHV kaposin protein (ORF K12) were detected in 2 HLA-A*0201-positive subjects. The optimal CTL epitope was identified by HLA restriction analysis and peptide titration assays. These data describe a latent phase viral gene product targeted by CTL that may be relevant for KSHV immunopathogenesis.

  3. Dynamic visualization the whole process of cytotoxic T lymphocytes killing the B16 tumor cells in vitro

    NASA Astrophysics Data System (ADS)

    Qi, Shuhong; Zhang, Zhihong

    2016-03-01

    Cytotoxic T lymphocytes (CTLs) played a key role in the immune system to destroy the tumor cells. Although some mechanisms of CTLs killing the tumor cells are revealed already, the dynamic information of CTLs interaction with tumor cells are still not known very clearly. Here we used confocal microscopy to visualize the whole process of CTLs killing the tumor cells in vitro. The imaging data showed that CTLs destroyed the target tumor cells rapidly and efficiently. Several CTLs surrounded one or some tumor cells and the average time for CTLs destroying one tumor cell is just a few minutes in vitro. The study displayed the temporal events of CTLs interacting with tumor cells at the beginning and finally killing them and directly presented the efficient tumor cell cytotoxicity of the CTLs. The results helped us to deeply understand the mechanism of the CTLs destroying the tumor cells and to develop the cancer immunotherapy.

  4. From sabotage to camouflage: viral evasion of cytotoxic T lymphocyte and natural killer cell-mediated immunity.

    PubMed

    Farrell, H E; Davis-Poynter, N J

    1998-06-01

    The outcome of a virus infection is strongly influenced by interactions between host immune defences and virus 'antidefence' mechanisms. For many viruses, their continued survival depends on the speed of their attack:their capacity to replicate and transmit to uninfected hosts prior to their elimination by an effective immune response. In contrast, the success of persistent viruses lies in their capacity for immunological subterfuge: the evasion of host defence mechanism by either mutation (covered elsewhere in this issue, by Gould and Bangham, pp. 331-338) or interference with the action of host cellular proteins that are important components of the immune response. This review will focus on the strategies employed by persistent viruses against two formidable host defences against virus infection: the CD8+ cytotoxic T lymphocyte (CTL) and natural killer (NK) cell responses.

  5. Inhibition of alloreactive cytotoxic T lymphocytes by peptides from the alpha 2 domain of HLA-A2.

    PubMed

    Parham, P; Clayberger, C; Zorn, S L; Ludwig, D S; Schoolnik, G K; Krensky, A M

    Class I major histocompatibility complex (MHC) molecules function in the recognition of antigens by cytotoxic T lymphocytes (CTL). Although this biological role is firmly established and much has been learnt about their structure and polymorphic variation, little is known of the regions of class I molecules that are involved in functional interactions with components of the T-cell surface. Here we show that peptides derived from residues 98-113 of the alpha 2 domain of HLA-A2 specifically inhibit the recognition of target cells by many HLA-A2-specific CTL. In addition to identifying a region that is probably involved in binding the T-cell receptor these results raise the possibility that alloreactive CTL may recognize degraded fragments of class I histocompatibility antigens. PMID:2433598

  6. A Multiepitope of XBP1, CD138 and CS1 Peptides Induces Myeloma-Specific Cytotoxic T lymphocytes in T cells of Smoldering Myeloma Patients

    PubMed Central

    Bae, Jooeun; Prabhala, Rao; Voskertchian, Annie; Brown, Andrew; Maguire, Craig; Richardson, Paul; Dranoff, Glen; Anderson, Kenneth C.; Munshi, Nikhil C.

    2014-01-01

    We evaluated a cocktail of HLA-A2-specific peptides including heteroclitic XBP1 US184-192 (YISPWILAV), heteroclitic XBP1 SP367-375 (YLFPQLISV), native CD138260-268 (GLVGLIFAV) and native CS1239-247 (SLFVLGLFL), for their ability to elicit multipeptide specific cytotoxic T lymphocytes (MP-CTL) using T cells from smoldering multiple myeloma (SMM) patients. Our results demonstrate that MP-CTL generated from SMM patients’ T cells show effective anti-MM responses including CD137 (4-1BB) upregulation, CTL proliferation, IFN-γ production, and degranulation (CD107a) in an HLA-A2-restricted and peptide-specific manner. Phenotypically, we observed increased total CD3+CD8+ T cells (>80%) and cellular activation (CD69+) within the memory SMM MP-CTL (CD45RO+/CD3+CD8+) subset after repeated multipeptide stimulation. Importantly, SMM patients could be categorized into distinct groups by their level of MP-CTL expansion and anti-tumor activity. In high responders, the effector memory (CCR7-CD45RO+/CD3+CD8+) T cell subset was enriched, while the remaining responders’ CTL contained a higher frequency of the terminal effector (CCR7-CD45RO-/CD3+CD8+) subset. These results suggest that this multipeptide cocktail has the potential to induce effective and durable memory MP-CTL in SMM patients. Therefore, our findings provide the rationale for clinical evaluation of a therapeutic vaccine to prevent or delay progression of SMM to active disease. PMID:24935722

  7. A multiepitope of XBP1, CD138 and CS1 peptides induces myeloma-specific cytotoxic T lymphocytes in T cells of smoldering myeloma patients.

    PubMed

    Bae, J; Prabhala, R; Voskertchian, A; Brown, A; Maguire, C; Richardson, P; Dranoff, G; Anderson, K C; Munshi, N C

    2015-01-01

    We evaluated a cocktail of HLA-A2-specific peptides including heteroclitic XBP1 US184-192 (YISPWILAV), heteroclitic XBP1 SP367-375 (YLFPQLISV), native CD138260-268 (GLVGLIFAV) and native CS1239-247 (SLFVLGLFL), for their ability to elicit multipeptide-specific cytotoxic T lymphocytes (MP-CTLs) using T cells from smoldering multiple myeloma (SMM) patients. Our results demonstrate that MP-CTLs generated from SMM patients' T cells show effective anti-MM responses including CD137 (4-1BB) upregulation, CTL proliferation, interferon-γ production and degranulation (CD107a) in an HLA-A2-restricted and peptide-specific manner. Phenotypically, we observed increased total CD3(+)CD8(+) T cells (>80%) and cellular activation (CD69(+)) within the memory SMM MP-CTL (CD45RO(+)/CD3(+)CD8(+)) subset after repeated multipeptide stimulation. Importantly, SMM patients could be categorized into distinct groups by their level of MP-CTL expansion and antitumor activity. In high responders, the effector memory (CCR7(-)CD45RO(+)/CD3(+)CD8(+)) T-cell subset was enriched, whereas the remaining responders' CTL contained a higher frequency of the terminal effector (CCR7(-)CD45RO(-)/CD3(+)CD8(+)) subset. These results suggest that this multipeptide cocktail has the potential to induce effective and durable memory MP-CTL in SMM patients. Therefore, our findings provide the rationale for clinical evaluation of a therapeutic vaccine to prevent or delay progression of SMM to active disease. PMID:24935722

  8. Cytotoxic T lymphocytes from cattle immunized against Theileria parva exhibit pronounced cross-reactivity among different strain-specific epitopes of the Tp1 antigen.

    PubMed

    Steinaa, L; Saya, R; Awino, E; Toye, P

    2012-02-15

    The protozoan parasite Theileria parva causes a usually fatal disease in cattle, known as East Coast fever. Cattle can be vaccinated by injecting live parasites simultaneously with long acting oxytetracycline (the infection and treatment method, ITM). The immunity induced by ITM is believed to be mediated by cytotoxic T lymphocytes (CTL). Although effective, the ITM vaccine has disadvantages such as the need for a liquid nitrogen cold chain and a complex production process, which may be overcome by the development of a subunit vaccine. However, the high level of antigenic polymorphism among different strains of T. parva may hinder the development of a subunit vaccine aimed at induction of a protective CTL response. In this study, the CTL cross-reactivity among T. parva strains was examined. The Tp1(214-224) epitope has previously been shown to be recognized by cattle of the A18 BoLA type. Three different variants of this epitope have been identified from different T. parva strains. Here, bulk CTL and CTL clones were generated from two animals using both the live sporozoite vaccine composed of three different strains and a Muguga strain for immunization. The cross-reactivity of these CTL with the three variant Tp1 epitopes was examined in interferon gamma ELISPOT assays and CTL killing assays. CD8(+) cells from both animals cross-reacted with the three variant CTL epitopes in interferon gamma ELISPOT assays, although the CD8(+) cells from the Muguga-immunized animal showed a more epitope restricted response. Clones from the vaccine immunized animal showed diverse response patterns with clones responding to each variant peptide. Although some variability in the cytotoxic response was observed, overall strong cross-reactivity among the variant Tp1 epitopes was seen in both animals. Such epitope polymorphism does not, in this case, serve as a potential challenge in a putative subunit vaccine as it would be sufficient to only include one of the variant epitopes.

  9. Multifunctional nanoparticles co-delivering Trp2 peptide and CpG adjuvant induce potent cytotoxic T-lymphocyte response against melanoma and its lung metastasis.

    PubMed

    Xu, Zhenghong; Ramishetti, Srinivas; Tseng, Yu-Cheng; Guo, Shutao; Wang, Yuhua; Huang, Leaf

    2013-11-28

    Immunotherapy has shown the potential to become an essential component of the successful treatment of various malignancies. In many cases, such as in melanoma, however, induction of a potent and specific T-cell response against the endogenous antigen or self-antigen still remains a major challenge. To induce a potent MHC I-restricted cytotoxic T-lymphocyte (CTL) response, cytosol delivery of an exogenous antigen into dendritic cells is preferred, if not required. Lipid-calcium-phosphate (LCP) nanoparticles represent a new class of intracellular delivery systems for impermeable drugs. We are interested in exploring the potential of LCP NPs for use as a peptide vaccine delivery system for cancer therapy. To increase the encapsulation of Trp2 peptide into the calcium phosphate precipitate core of LCP, two phosphor-serine residues were added to the N-terminal of the peptide (p-Trp2). CpG ODN was also co-encapsulated with p-Trp2 as an adjuvant. The NPs were further modified with mannose to enhance and prolong the cargo deposit into the lymph nodes (LNs), which ensured persistent antigen loading and stimulation. Compared with free Trp2 peptide/CpG, vaccination with LCP encapsulating p-Trp2 and CpG resulted in superior inhibition of tumor growth in both B16F10 subcutaneous and lung metastasis models. An IFN-γ production assay and in vivo CTL response study revealed that the improved efficacy was a result of a Trp2-specific immune response. Thus, encapsulation of phospho-peptide antigens into LCP may be a promising strategy for enhancing the immunogenicity of poorly immunogenic self-antigens for cancer therapy.

  10. Recognition of HLA-A2 and -B7 antigens by cloned cytotoxic T lymphocytes after gene transfer into human and monkey, but not mouse, cells.

    PubMed Central

    Barbosa, J A; Mentzer, S J; Minowada, G; Strominger, J L; Burakoff, S J; Biro, P A

    1984-01-01

    The genes that code for the human major histocompatibility class I antigens, HLA-A2 and HLA-B7, were introduced into human, monkey, and mouse cell lines by cotransfection with suitable biochemical markers and the fluorescence-activated cell sorter was used to identify and/or select stable cell populations expressing high surface levels of these antigens. Levels of expression obtained were similar to those observed for endogenous HLA antigens on various human cell lines and were 25-80% of those observed on the human B-lymphoblastoid cell line JY. Serologically defined HLA-A2 and HLA-B7 polymorphic determinants remained intact on all transfected recipient cells analyzed. Cloned human allospecific cytotoxic T lymphocytes (CTL) specific for HLA-A2 or HLA-B7 were capable of lysing appropriate HLA-transfected human cells with comparable efficiency to JY cell lysis. Two of 10 CTL clones lysed appropriate monkey cell transfectants with approximately equal to 20% the efficiency of human cell transfectants. No specific lysis of any HLA-transfected mouse cell lines, including a B cell lymphoma, was observed despite comparable levels of surface antigen expression or after induction of higher levels by mouse gamma-interferon. Furthermore, L cells expressing human beta 2-microglobulin in addition to HLA-A2 or -B7 were not lysed by these CTL. Thus, an additional species-specific component may be involved in lysis by allogeneic CTL--possibly related to the function(s) of other surface proteins on target cells. PMID:6390442

  11. Immunization with antigenic peptides complexed with β-glucan induces potent cytotoxic T-lymphocyte activity in combination with CpG-ODNs.

    PubMed

    Mochizuki, Shinichi; Morishita, Hiromi; Kobiyama, Kouji; Aoshi, Taiki; Ishii, Ken J; Sakurai, Kazuo

    2015-12-28

    The induction of antigen-specific immune responses requires immunization with not only antigens, but also adjuvants. CpG oligonucleotides (CpG-ODNs) are well-known ligands for Toll-like receptor 9 and a potent adjuvant that induces both Th1-type humoral and cellular immune responses including cytotoxic T-lymphocyte responses. We previously demonstrated that β-glucan schizophyllan (SPG) can form complexes with CpG-ODNs with attached dA40 (CpG-dA/SPG), which can accumulate in macrophages in the draining inguinal lymph nodes and induce strong immune responses by co-administration of antigenic proteins, namely ovalbumin (OVA). Immunization with antigenic peptides, OVA257-264, did not induce these antigen-specific immune responses even in combination with CpG-dA/SPG, indicating that peptides require a carrier to antigen presenting cells. In this study, we prepared conjugates comprising OVA257-264 and dA40, and made complexes with SPG. Immunization with OVA257-264-dA/SPG induced peptide-specific immune responses in combination with CpG-dA regardless of complexation with SPG both in vitro and in vivo. When splenocytes from immunized mice were incubated with E.G7-OVA tumor model cells presenting OVA peptides, the number of cells drastically decreased after 24h. Furthermore, mice pre-immunized with OVA257-264-dA/SPG and CpG-ODNs exhibited a long delay in tumor growth after tumor inoculation. Therefore, these peptide-dA/SPG and CpG-dA/SPG complexes could be used as a potent vaccine for the treatment of cancers and infectious diseases. PMID:26562685

  12. Identification of novel myeloma-specific XBP1 peptides able to generate cytotoxic T lymphocytes: A potential therapeutic application in multiple myeloma

    PubMed Central

    Bae, Jooeun; Carrasco, Ruben; Lee, Ann-Hwee; Tai, Yu-Tzu; Anderson, Kenneth C.; Munshi, Nikhil C.

    2012-01-01

    The purpose of these studies was to identify HLA-A2+ immunogenic peptides derived from XBP1 antigens to induce a multiple myeloma (MM)-specific immune response. Six native peptides from non-spliced XBP1 antigen and three native peptides from spliced XBP1 antigen were selected and evaluated for their HLA-A2 specificity. Among them, XBP1184–192, XBP1 SP196–204 and XBP1 SP367–375 peptides showed the highest level of binding affinity, but not stability to HLA-A2 molecules. Novel heteroclitic XBP1 peptides, YISPWILAV or YLFPQLISV, demonstrated a significant improvement in HLA-A2 stability from their native XBP1184–192 or XBP1 SP367–375 peptide, respectively. Cytotoxic T lymphocytes generated by repeated stimulation of CD3+ T cells with each HLA-A2-specific heteroclitic peptide showed an increased percentage of CD8+ (cytotoxic) and CD69+/CD45RO+ (activated memory) T cells and a lower percentage of CD4+ (helper) and CD45RA+/CCR7+ (naïve) T cells, which were distinct from the control T cells. Functionally, the CTLs demonstrated MM-specific and HLA-A2-restricted proliferation, IFN-γ secretion and cytotoxic acivity in response to MM cell lines and importantly, cytotoxicty against primary MM cells. These data demonstrate the distinct immunogenic characteristics of unique heteroclitic XBP1 peptides which induce MM-specific CTLs and highlights their potential application for immunotherapy to treat the patients with MM or its pre-malignant condition. PMID:21660045

  13. Myeloma-specific multiple peptides able to generate cytotoxic T lymphocytes: A potential therapeutic application in multiple myeloma and other plasma cell disorders

    PubMed Central

    Bae, Jooeun; Smith, Robert; Daley, John; Mimura, Naoya; Tai, Yu-Tzu; Anderson, Kenneth C.; Munshi, Nikhil C.

    2013-01-01

    Purpose The efficacy of peptide vaccines may be enhanced by stimulating immune cells with multiple peptides derived from distinct tumor-associated antigens. We have evaluated the heteroclitic XBP1 US184–192 (YISPWILAV), heteroclitic XBP1 SP367–375 (YLFPQLISV), native CD138260–268 (GLVGLIFAV), and native CS1239–247 (SLFVLGLFL) peptides, which have strong HLA-A2 affinity and immunogenicity in combination, for their ability to elicit multiple myeloma antigen-specific responses. Experimental Design Multipeptide-specific cytotoxic T lymphocytes (MP-CTL) were generated by the stimulation of CD3+ T lymphocytes from HLA-A2+ individuals with either autologous mature dendritic cells or T2 cells pulsed with a cocktail of these four peptides. Results The peptide cocktail did not compromise tumor antigen-specific activity of CTL. MP-CTL displayed increased total, effector memory (CCR7−CD45RO+), and activated (CD69+) CD3+CD8+ T lymphocytes. In addition, MP-CTL demonstrated IFN-γ production, cell proliferation, and cytotoxicity against HLA-A2+ multiple myeloma cells, including HLA-A2+ MM patients’ cells. Importantly, MP-CTL showed specific responses in functional assays to each relevant peptide, but not to an irrelevant HLA-A2 specific CMV pp65 (NLVPMVATV) peptide. Conclusions These results highlight the potential therapeutic application of vaccination with a cocktail of HLA-A2 specific peptides to induce CTL with a broad spectrum of immune responses against multiple myeloma antigens. PMID:22753586

  14. Cationic micelle delivery of Trp2 peptide for efficient lymphatic draining and enhanced cytotoxic T-lymphocyte responses.

    PubMed

    Zeng, Qin; Jiang, Hao; Wang, Ting; Zhang, Zhirong; Gong, Tao; Sun, Xun

    2015-02-28

    Neutral particles 20-45 nm in diameter showed potential as tumor antigen vectors because they targeted the draining lymph nodes after subcutaneous injection. However, they were weakly immune-stimulatory and could also spread throughout the body, raising the risk of systemic toxicity. Here we explored whether incorporating positively charged amphiphilic polymers into micelles improves their site specificity and immunogenicity. Cationic polyethylenimine (2k)-stearic acid (PSA) micelles were loaded with the melanoma antigen peptide Trp2; they showed an average size of 28.7±8.2 nm and an encapsulation efficiency of 99.21±5.38%. Empty PSA micelles acted as a robust adjuvant in vitro, promoting maturation, proliferation and migration of bone marrow-derived dendritic cells in a dose-dependent manner. After subcutaneous injection into mice, Trp2-loaded PSA micelles accumulated preferentially in the medulla and paracortex of the draining lymph nodes and were present at negligible levels in the systemic circulation. Mice immunized with Trp2-loaded PSA micelles showed significantly higher Trp2-specific cytotoxic T lymphocyte activity than mice immunized with free Trp2 or a mixture of Trp2 and empty PSA micelles. In a B16-F10 murine melanoma model, Trp2-loaded PSA micelles inhibited tumor growth significantly more than did free Trp2 and PSA micelles caused less systemic toxicity. These findings suggest that cationic PSA micelles loaded with Trp2 may be a potential approach for melanoma immunotherapy.

  15. Determinants of human immunodeficiency virus type 1 escape from the primary CD8+ cytotoxic T lymphocyte response.

    PubMed

    Jones, Nicola A; Wei, Xiping; Flower, Darren R; Wong, Mailee; Michor, Franziska; Saag, Michael S; Hahn, Beatrice H; Nowak, Martin A; Shaw, George M; Borrow, Persephone

    2004-11-15

    CD8+ cytotoxic T lymphocytes (CTLs) play an important role in containment of virus replication in primary human immunodeficiency virus (HIV) infection. HIV's ability to mutate to escape from CTL pressure is increasingly recognized; but comprehensive studies of escape from the CD8 T cell response in primary HIV infection are currently lacking. Here, we have fully characterized the primary CTL response to autologous virus Env, Gag, and Tat proteins in three patients, and investigated the extent, kinetics, and mechanisms of viral escape from epitope-specific components of the response. In all three individuals, we observed variation beginning within weeks of infection at epitope-containing sites in the viral quasispecies, which conferred escape by mechanisms including altered peptide presentation/recognition and altered antigen processing. The number of epitope-containing regions exhibiting evidence of early CTL escape ranged from 1 out of 21 in a subject who controlled viral replication effectively to 5 out of 7 in a subject who did not. Evaluation of the extent and kinetics of HIV-1 escape from >40 different epitope-specific CD8 T cell responses enabled analysis of factors determining escape and suggested that escape is restricted by costs to intrinsic viral fitness and by broad, codominant distribution of CTL-mediated pressure on viral replication.

  16. Increased numbers of granzyme-B-expressing cytotoxic T-lymphocytes in the small intestine of HIV-infected patients.

    PubMed

    Snijders, F; Wever, P C; Danner, S A; Hack, C E; ten Kate, F J; ten Berge, I J

    1996-07-01

    The objective of this study was to determine whether granzyme B-expressing cells, which identify activated cytotoxic lymphocytes, are present in the small intestinal mucosa of human immunodeficiency virus (HIV)-infected patients with and without diarrhea. Therefore, duodenal biopsy specimens from 29 HIV-infected patients (11 with diarrhea and 18 without diarrhea) and 15 control patients were stained for the presence of granzyme B expressing cells. In HIV-infected patients, a significantly increased expression of granzyme B in the lamina propria was observed (p = 0.00001): In 22 of 29 patients, at least 5-10 cells per high-power field were counted. In contrast, in 13 of 15 control patients, granzyme B was not expressed or minimally so, and in two others a maximum of five granzyme-B-expressing cells could be detected per high-power field. No significant difference was found between the HIV-infected patients with and without diarrhea. Double staining revealed that the granzyme-B-expressing cells were mainly CD3 positive. These data show that activated cytotoxic T lymphocytes (CTLs) are present in the duodenal mucosa of HIV-infected patients. No relation between the number of CTLs and the presence of diarrhea was demonstrated. CTLs are known to be involved in the pathogenesis of HIV infection and in the production of tissue injury, but their functional role in intestinal HIV-related pathology has yet to be elucidated.

  17. Hypophysitis Induced by Monoclonal Antibodies to Cytotoxic T Lymphocyte Antigen 4: Challenges from a New Cause of a Rare Disease

    PubMed Central

    Torino, Francesco; Barnabei, Agnese; De Vecchis, Liana; Salvatori, Roberto

    2012-01-01

    Specific human monoclonal antibodies antagonize cytotoxic T-lymphocyte antigen 4 (anti–CTLA-4 mAbs), a negative regulator of the immune system, inducing unrestrained T-cell activation. In patients with advanced or metastatic melanoma, one of these agents, ipilimumab, produced considerable disease control rates and, for the first time, a clear improvement in overall survival outcomes. However, accumulating clinical experience with anti–CTLA-4 mAbs identified a novel syndrome of autoimmune and autoinflammatory side effects, designated as “immune-related adverse events,” including mainly rash, colitis, and hepatitis. Autoimmune hypophysitis has emerged as a distinctive side effect induced by anti–CTLA-4 mAbs. This condition may be life threatening because of adrenal insufficiency if not promptly recognized, but it may easily be diagnosed and treated if clinically suspected. Hypopituitarism caused by these agents is rarely reversible and prolonged or life-long substitutive hormonal treatment is often required. The precise mechanism of injury to the pituitary triggered by anti–CTLA-4 mAbs is yet to be fully elucidated. PMID:22477725

  18. Cancer-induced defective cytotoxic T lymphocyte effector function: another mechanism how antigenic tumors escape immune-mediated killing.

    PubMed Central

    Radoja, S.; Frey, A. B.

    2000-01-01

    BACKGROUND: The notion that a deficit in immune cell functions permits tumor growth has received experimental support with the discovery of several different biochemical defects in T lymphocytes that infiltrate cancers. Decreased levels of enzymes involved with T-cell signal transduction have been reported by several laboratories, suggesting that tumors or host cells recruited to the tumor site actively down-regulate antitumor T-cell immune response. This permits tumor escape from immune-mediated killing. The possibility that defects in T-cell signal transduction can be reversed, which would potentially permit successful vaccination or adoptive immunotherapy, motivates renewed interest in the field. Summarizing the literature concerning tumor-induced T-cell dysfunction, we focus on the end stage of immune response to human cancer, that of defective cytotoxic T lymphocyte killing function. Based on the data from several laboratories, we hypothesize a biochemical mechanism that accounts for the unusual phenotype of antitumor T-cell accumulation in tumors, but with defective killing function. PMID:10972084

  19. Targeting miR-23a in CD8+ cytotoxic T lymphocytes prevents tumor-dependent immunosuppression

    PubMed Central

    Lin, Regina; Chen, Ling; Chen, Gang; Hu, Chunyan; Jiang, Shan; Sevilla, Jose; Wan, Ying; Sampson, John H.; Zhu, Bo; Li, Qi-Jing

    2014-01-01

    CD8+ cytotoxic T lymphocytes (CTLs) have potent antitumor activity and therefore are leading candidates for use in tumor immunotherapy. The application of CTLs for clinical use has been limited by the susceptibility of ex vivo–expanded CTLs to become dysfunctional in response to immunosuppressive microenvironments. Here, we developed a microRNA-targeting (miRNA-targeting) approach that augments CTL cytotoxicity and preserves immunocompetence. Specifically, we screened for miRNAs that modulate cytotoxicity and identified miR-23a as a strong functional repressor of the transcription factor BLIMP-1, which promotes CTL cytotoxicity and effector cell differentiation. In a cohort of advanced lung cancer patients, miR-23a was upregulated in tumor-infiltrating CTLs, and expression correlated with impaired antitumor potential of patient CTLs. We determined that tumor-derived TGF-β directly suppresses CTL immune function by elevating miR-23a and downregulating BLIMP-1. Functional blocking of miR-23a in human CTLs enhanced granzyme B expression, and in mice with established tumors, immunotherapy with just a small number of tumor-specific CTLs in which miR-23a was inhibited robustly hindered tumor progression. Together, our findings provide a miRNA-based strategy that subverts the immunosuppression of CTLs that is often observed during adoptive cell transfer tumor immunotherapy and identify a TGF-β–mediated tumor immune-evasion pathway. PMID:25347474

  20. Identification of cytotoxic T lymphocyte epitopes on swine viruses: multi-epitope design for universal T cell vaccine.

    PubMed

    Liao, Yu-Chieh; Lin, Hsin-Hung; Lin, Chieh-Hua; Chung, Wen-Bin

    2013-01-01

    Classical swine fever (CSF), foot-and-mouth disease (FMD) and porcine reproductive and respiratory syndrome (PRRS) are the primary diseases affecting the pig industry globally. Vaccine induced CD8(+) T cell-mediated immune response might be long-lived and cross-serotype and thus deserve further attention. Although large panels of synthetic overlapping peptides spanning the entire length of the polyproteins of a virus facilitate the detection of cytotoxic T lymphocyte (CTL) epitopes, it is an exceedingly costly and cumbersome approach. Alternatively, computational predictions have been proven to be of satisfactory accuracy and are easily performed. Such a method enables the systematic identification of genome-wide CTL epitopes by incorporating epitope prediction tools in analyzing large numbers of viral sequences. In this study, we have implemented an integrated bioinformatics pipeline for the identification of CTL epitopes of swine viruses including the CSF virus (CSFV), FMD virus (FMDV) and PRRS virus (PRRSV) and assembled these epitopes on a web resource to facilitate vaccine design. Identification of epitopes for cross protections to different subtypes of virus are also reported in this study and may be useful for the development of a universal vaccine against such viral infections among the swine population. The CTL epitopes identified in this study have been evaluated in silico and possibly provide more and wider protection in compared to traditional single-reference vaccine design. The web resource is free and open to all users through http://sb.nhri.org.tw/ICES. PMID:24358361

  1. Antigen-specific cytotoxic T lymphocytes target airway CD103+ and CD11b+ dendritic cells to suppress allergic inflammation.

    PubMed

    Daniels, N J; Hyde, E; Ghosh, S; Seo, K; Price, K M; Hoshino, K; Kaisho, T; Okada, T; Ronchese, F

    2016-01-01

    Allergic airway inflammation is driven by the recognition of inhaled allergen by T helper type 2 (Th2) cells in the airway and lung. Allergen-specific cytotoxic T lymphocytes (CTLs) can strongly reduce airway inflammation, however, the mechanism of their inhibitory activity is not fully defined. We used mouse models to show that allergen-specific CTLs reduced early cytokine production by Th2 cells in lung, and their subsequent accumulation and production of interleukin (IL)-4 and IL-13. In addition, treatment with specific CTLs also increased the proportion of caspase(+) dendritic cells (DCs) in mediastinal lymph node (MLN), and decreased the numbers of CD103(+) and CD11b(+) DCs in the lung. This decrease required expression of the cytotoxic mediator perforin in CTLs and of the appropriate MHC-antigen ligand on DCs, suggesting that direct CTL-DC contact was necessary. Lastly, lung imaging experiments revealed that in airway-challenged mice XCR1-GFP(+) DCs, corresponding to the CD103(+) DC subset, and XCR1-GFP(-) CD11c(+) cells, which include CD11b(+) DCs and alveolar macrophages, both clustered in the areas surrounding the small airways and were closely associated with allergen-specific CTLs. Thus, allergen-specific CTLs reduce allergic airway inflammation by depleting CD103(+) and CD11b(+) DC populations in the lung, and may constitute a mechanism through which allergic immune responses are regulated.

  2. Cystine-knot peptides targeting cancer-relevant human cytotoxic T lymphocyte-associated antigen 4 (CTLA-4).

    PubMed

    Maaß, Franziska; Wüstehube-Lausch, Joycelyn; Dickgießer, Stephan; Valldorf, Bernhard; Reinwarth, Michael; Schmoldt, Hans-Ulrich; Daneschdar, Matin; Avrutina, Olga; Sahin, Ugur; Kolmar, Harald

    2015-08-01

    Cystine-knot peptides sharing a common fold but displaying a notably large diversity within the primary structure of flanking loops have shown great potential as scaffolds for the development of therapeutic and diagnostic agents. In this study, we demonstrated that the cystine-knot peptide MCoTI-II, a trypsin inhibitor from Momordica cochinchinensis, can be engineered to bind to cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), an inhibitory receptor expressed by T lymphocytes, that has emerged as a target for the treatment of metastatic melanoma. Directed evolution was used to convert a cystine-knot trypsin inhibitor into a CTLA-4 binder by screening a library of variants using yeast surface display. A set of cystine-knot peptides possessing dissociation constants in the micromolar range was obtained; the most potent variant was synthesized chemically. Successive conjugation with neutravidin, fusion to antibody Fc domain or the oligomerization domain of C4b binding protein resulted in oligovalent variants that possessed enhanced (up to 400-fold) dissociation constants in the nanomolar range. Our data indicate that display of multiple knottin peptides on an oligomeric scaffold protein is a valid strategy to improve their functional affinity with ramifications for applications in diagnostics and therapy. PMID:25964162

  3. Determinants of human immunodeficiency virus type 1 escape from the primary CD8+ cytotoxic T lymphocyte response.

    PubMed

    Jones, Nicola A; Wei, Xiping; Flower, Darren R; Wong, Mailee; Michor, Franziska; Saag, Michael S; Hahn, Beatrice H; Nowak, Martin A; Shaw, George M; Borrow, Persephone

    2004-11-15

    CD8+ cytotoxic T lymphocytes (CTLs) play an important role in containment of virus replication in primary human immunodeficiency virus (HIV) infection. HIV's ability to mutate to escape from CTL pressure is increasingly recognized; but comprehensive studies of escape from the CD8 T cell response in primary HIV infection are currently lacking. Here, we have fully characterized the primary CTL response to autologous virus Env, Gag, and Tat proteins in three patients, and investigated the extent, kinetics, and mechanisms of viral escape from epitope-specific components of the response. In all three individuals, we observed variation beginning within weeks of infection at epitope-containing sites in the viral quasispecies, which conferred escape by mechanisms including altered peptide presentation/recognition and altered antigen processing. The number of epitope-containing regions exhibiting evidence of early CTL escape ranged from 1 out of 21 in a subject who controlled viral replication effectively to 5 out of 7 in a subject who did not. Evaluation of the extent and kinetics of HIV-1 escape from >40 different epitope-specific CD8 T cell responses enabled analysis of factors determining escape and suggested that escape is restricted by costs to intrinsic viral fitness and by broad, codominant distribution of CTL-mediated pressure on viral replication. PMID:15545352

  4. Dendritic cells transduced with Rsf-1/HBXAP gene generate specific cytotoxic T lymphocytes against ovarian cancer in vitro

    SciTech Connect

    Sun, Li; Kong, Beihua; Sheng, Xiugui; Sheu, Jim Jinn-Chyuan; Shih, Ie-Ming

    2010-04-09

    Recently, some studies have indicated that Rsf-1/HBXAP plays a role in chromatin remodeling and transcriptional regulation that may contribute to tumorigenesis in ovarian cancer. The present study demonstrates that using dendritic cells (DCs) from human cord blood CD34{sup +} cells transduced with Rsf-1/HBXAP DNA plasmids by nucleofection generate specific cytotoxic T lymphocytes (CTL) against ovarian cancer in vitro. After transfection, DCs were analyzed for Rsf-1/HBXAP mRNA expression by RT-PCR and protein expression by Western blot. Then the DC phenotypes, T-cell stimulatory capacity, endocytic activity and migration capacity were explored by flow cytometry analysis, allogeneic mixed lymphocyte reaction, endocytosis and transwell chemotaxis assay, respectively. After transfection, Rsf-1/HBXAP expression was detected at mRNA and protein levels. Allogeneic T-cell proliferation induced by transfected DCs was obviously higher than non-transfected DCs, but the endocytosis capacity and migratory ability were not different. Rsf-1/HBXAP gene-transduced DCs could induce antigen-specific CTL and generate a very potent cytotoxicity to OVCAR3 cells. These data suggest that Rsf-1/HBXAP gene-transduced DCs may be a potential adjuvant immunotherapy for ovarian cancer in clinical applications.

  5. Folate-Modified Chitosan Nanoparticles Coated Interferon-Inducible Protein-10 Gene Enhance Cytotoxic T Lymphocytes' Responses to Hepatocellular Carcinoma.

    PubMed

    Duan, Siliang; Song, Mongkhoune; He, Jian; Zhou, Nuo; Zhou, Sufang; Zhao, Jing; Fang, Yuan; Yi, Peng; Huang, Xianing; Luo, Guorong; Lai, Chunhui; Yu, Xia; Zhang, Zhiyong; Xie, Yuan; Zhao, Yongxiang; Lu, Xiaoling

    2016-04-01

    Adoptive therapy using tumor antigen-specific cytotoxic T lymphocytes (CTLs) is a promising approach for treatment of human cancers. Due to immune suppression in cancer patients, it is difficult for tumor antigen-specific CTLs to arrive at tumor tissues. Interferon-inducible protein-10 (IP-10) is a powerful chemokine that effectively attracts CTLs to tumor tissues and improves their anti-tumor activity. Increase over expression of IP-10 in tumor tissues can efficiently promote efficacy of adoptive therapy. Folate-modified chitosan nanoparticles coating the human IP-10 gene (FA-CS-hIP-10) were therefore developed in this study. The FA-CS-hIP-10 nanoparticles were specifically bound to folate receptors on hepatoma cells and promoted the expression of IP-10, to improve the activity of pMAGE-A1(278-286) specific CTLs. Combination of the FA-CS-hIP-10 and pMAGE-A1(278-286) specific CD8+ CTLs efficiently increased secretion of IFN-γ, inhibited tumor growth and extended survival of nude mice with subcutaneously transplanted human hepatocellular carcinoma. Our results demonstrated that the mechanism behind this novel therapeutic approach involved inhibition of angiogenesis and proliferation, and also promoted apoptosis of tumor cells. Our study provides a potentially novel approach for treatment of human hepatocellular carcinoma by improving the activity of tumor antigen-specific CTLs. PMID:27301196

  6. Cystine-knot peptides targeting cancer-relevant human cytotoxic T lymphocyte-associated antigen 4 (CTLA-4).

    PubMed

    Maaß, Franziska; Wüstehube-Lausch, Joycelyn; Dickgießer, Stephan; Valldorf, Bernhard; Reinwarth, Michael; Schmoldt, Hans-Ulrich; Daneschdar, Matin; Avrutina, Olga; Sahin, Ugur; Kolmar, Harald

    2015-08-01

    Cystine-knot peptides sharing a common fold but displaying a notably large diversity within the primary structure of flanking loops have shown great potential as scaffolds for the development of therapeutic and diagnostic agents. In this study, we demonstrated that the cystine-knot peptide MCoTI-II, a trypsin inhibitor from Momordica cochinchinensis, can be engineered to bind to cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), an inhibitory receptor expressed by T lymphocytes, that has emerged as a target for the treatment of metastatic melanoma. Directed evolution was used to convert a cystine-knot trypsin inhibitor into a CTLA-4 binder by screening a library of variants using yeast surface display. A set of cystine-knot peptides possessing dissociation constants in the micromolar range was obtained; the most potent variant was synthesized chemically. Successive conjugation with neutravidin, fusion to antibody Fc domain or the oligomerization domain of C4b binding protein resulted in oligovalent variants that possessed enhanced (up to 400-fold) dissociation constants in the nanomolar range. Our data indicate that display of multiple knottin peptides on an oligomeric scaffold protein is a valid strategy to improve their functional affinity with ramifications for applications in diagnostics and therapy.

  7. Comparative structural analysis of HLA-A2 antigens distinguishable by cytotoxic T lymphocytes: variants M7 and DR1.

    PubMed

    Krangel, M S; Taketani, S; Biddison, W E; Strong, D M; Strominger, J L

    1982-11-23

    Comparative primary structural analyses have begun to elucidate polymorphic residues and segments of the class I antigens of the major histocompatibility complex, at least some of which presumably contribute to determinants important in immune recognition events. HLA-A2 structural variants have been described which are serologically indistinguishable from other HLA-A2 antigens, yet which can be recognized neither by HLA-A2 specific alloimmune nor by HLA-A2 restricted, virus immune cytotoxic T lymphocytes. This study utilizes double-label tryptic peptide comparisons in combination with both conventional and microsequence analyses to investigate the structure of two such variants, M7 and DR1. We find that these variants are identical with each other and differ from the predominant HLA-A2 heavy chain species by a glutamine to arginine substitution at residue 43, by an unidentified substitution in the tryptic peptide spanning residues 147-157, and by an as yet poorly defined alteration in glycosylation. Structural information from these and other variants should be useful in precisely defining functionally important determinants on the molecule. PMID:6983890

  8. A mutated HLA-A2 molecule recognized by autologous cytotoxic T lymphocytes on a human renal cell carcinoma

    PubMed Central

    1996-01-01

    Many human tumor cells have been shown to express antigens that are recognized by autologous cytotoxic T lymphocytes (CTL) and the molecular nature of a number of melanoma antigens has been defined recently. Here we describe the characterization of an antigen recognized on a renal cell carcinoma by autologous CTL clones. This antigen is encoded by the HLA-A2 gene present in the tumor cells. The sequence of this gene differs from the HLA-A2 sequence found in autologous peripheral blood lymphocytes by a point mutation that results in an arginine to isoleucine exchange at residue 170, which is located on the alpha-helix of the alpha 2 domain. Transfection experiments with the normal and mutated HLA-A2 cDNA demonstrated that this amino acid replacement was responsible for the recognition of the HLA-A2 molecule expressed on the tumor cells. The mutant HLA-A2 gene was also detected in the original tumor tissue from the patient, excluding the possibility that the mutation had appeared in vitro. Thus, HLA class I molecules carrying a tumor-specific mutation can be involved in the recognition of tumor cells by autologous CTL. PMID:8676070

  9. Waiting times for the appearance of cytotoxic T-lymphocyte escape mutants in chronic HIV-1 infection

    SciTech Connect

    Liu Yi . E-mail: yiliu197@u.washington.edu; Mullins, James I.; Mittler, John E.

    2006-03-30

    The failure of HIV-1 to escape at some cytotoxic T-lymphocyte (CTL) epitopes has generally been explained in terms of viral fitness costs or ineffective or attenuated CTL responses. Relatively little attention has been paid to the evolutionary time required for escape mutants to be detected. This time is significantly affected by selection, mutation rates, the presence of other advantageous mutations, and the effective population size of HIV-1 in vivo (typically estimated to be {approx}10{sup 3} in chronically infected patients, though one study has estimated it to be {approx}10{sup 5}). Here, we use a forward simulator with experimentally estimated HIV-1 parameters to show that these delays can be substantial. For an effective population size of 10{sup 3}, even highly advantageous mutants (s = 0.5) may not be detected for a couple of years in chronically infected patients, while moderately advantageous escape mutants (s = 0.1) may not be detected for up to 10 years. Even with an effective population size of 10{sup 5}, a moderately advantageous escape mutant (s = 0.1) may not be detected in the population within 2 years if it has to compete with other selectively advantageous mutants. Stochastic evolutionary forces, therefore, in addition to viral fitness costs and ineffective or attenuated CTL responses, must be taken into account when assessing the selection of CTL escape mutations.

  10. Different responses are elicited in cytotoxic T lymphocytes by different levels of T cell receptor occupancy

    PubMed Central

    1996-01-01

    We have investigated the level of TCR occupancy required to elicit different biological responses in human CTL clones specific for an influenza matrix peptide. Specific cytotoxicity could be detected at extremely low peptide concentrations (10(-12) to 10(-15) M). However, IFN-gamma production, responsiveness to IL-2 and Ca++ fluxes were observed only at peptide concentrations > 10(-9) M, while autonomous proliferation required even higher peptide concentrations. In parallel experiments we measured TCR downregulation to estimate the number of TCRs triggered. We observed that at low peptide concentrations, where only cytotoxicity is triggered, TCR downregulation was hardly detectable. Conversely, induction of IFN-gamma production and proliferation required triggering of at least 20-50% of TCRs. Taken together these results indicate that a single CTL can graduate different biological responses as a function of antigen concentration and that killing of the specific target does not necessarily result in full activation. PMID:8666949

  11. Autoreactive cytotoxic T lymphocytes in human immunodeficiency virus type 1-infected subjects

    PubMed Central

    1996-01-01

    A subtractive analysis of peptides eluted from major histocompatibility complex (MHC) class I human histocompatibility leukocyte antigen (HLA)- A2.1 molecules purified from either human immunodeficiency virus type-1 (HIV-1)-infected or uninfected cells was performed using micro high- performance liquid chromatography and mass spectrometry. Three peptides unique to infected cells were identified and found to derive from a single protein, human vinculin, a structural protein not known to be involved in viral pathogenesis. Molecular and cytofluorometric analyses revealed vinculin mRNA and vinculin protein overexpression in B and T lymphocytes from HIV-1-infected individuals. Vinculin peptide-specific CTL activity was readily elicited from peripheral blood lymphocytes of the majority of HLA-A2.1+, HIV+ patients tested. Our observations suggest that atypical vinculin expression and MHC class I-mediated presentation of vinculin-derived peptides accompany HIV infection of lymphoid cells in vivo, with a resultant induction of antivinculin CTL in a significant portion of HIV+ (HLA-A2.1+) individuals. PMID:8676071

  12. In vitro activation of cytotoxic T-lymphocytes by hTERT-pulsed dendritic cells.

    PubMed

    Kryukov, Fedor; Ocadlíková, Darina; Kovárová, Lucie; Buresová, Ivana; Hájek, Roman; Michálek, Jaroslav

    2009-12-01

    Multiple myeloma has been considered a weakly immunogenic malignancy that can cause profound defects in the immune system. An important issue for the immunotherapy of myeloma is the identification of appropriate tumor-associated antigens (TAAs). Recently, hTERT (human telomerase reverse transcriptase) was detected on a majority of human malignancies. In the studies reported here, we studied antigen-specific and HLA-A2-restricted cytotoxic activity against an ARH77 myeloma cell line in vitro. An HLA-A2-specific hTERT-derived nonapeptide ((540)ILAKFLHWL(548)) was used as a TAA. Myeloma-specific cytotoxic activity of hTERT-reactive cytotoxic lymphocytes (CTLs) was established by repeated stimulation of the CTLs via dendritic cells loaded with hTERT-derived nonapeptide. These studies were able to demonstrate that hTERT-reactive T-lymphocytes can be identified and expanded using relatively simple in vitro techniques consisting of antigen-specific stimulation, immunomagnetic sorting, and then induction of rapid expansion. PMID:19908943

  13. Modulation of MUC1 mucin as an escape mechanism of breast cancer cells from autologous cytotoxic T-lymphocytes

    PubMed Central

    Kontani, K; Taguchi, O; Narita, T; Izawa, M; Hiraiwa, N; Zenita, K; Takeuchi, T; Murai, H; Miura, S; Kannagi, R

    2001-01-01

    MUC1 mucin is known to serve as a target molecule in the killing of breast cancer cells by cytotoxic T-lymphocytes (CTLs). We searched for a possible mechanism allowing tumour cells to escape from autologous CTLs. When the killing of breast cancer cells by autologous lymphocytes was examined in 26 patients with breast cancer, significant tumour cell lysis was observed in 8 patients, whereas virtually no autologous tumour cell lysis was detected in as many as 18 patients. In the patients who showed negligible tumour cell lysis, the autologous tumour cells expressed MUC1-related antigenic epitopes much more weakly than the tumour cells in the patients who exhibited strong cytotoxicity (significant statistically at P< 0.0005–0.0045), suggesting that the unresponsiveness of cancer cells to CTLs observed in these patients was mainly due to loss of MUC1 expression or modulation of its antigenicity. A breast cancer cell line, NZK-1, established from one of the cytotoxicity-negative patients, did not express MUC1 and was resistant to killing by CTLs, while control breast cancer cell lines expressing MUC-1 were readily killed by CTLs. Transfection of NZK-1 cells with MUC1 cDNA induced significant lysis by autologous T-lymphocytes. These results supported the importance of MUC1 mucin in autologous anti-tumour immunity, but suggested that the major escape mechanism of tumour cells from autologous T-lymphocytes is the loss and/or modulation of MUC1 antigenicity on tumour cells, which would limit the effectiveness of possible immunotherapy designed to target the MUC1 mucin. © 2001 Cancer Research Campaign http://www.bjcancer.com PMID:11336479

  14. Cytotoxic T lymphocyte-dependent tumor growth inhibition by a vascular endothelial growth factor-superantigen conjugate

    SciTech Connect

    Sun, Qingwen; Jiang, Songmin; Han, Baohui; Sun, Tongwen; Li, Zhengnan; Zhao, Lina; Gao, Qiang; Sun, Jialin

    2012-11-02

    Highlights: Black-Right-Pointing-Pointer We construct and purify a fusion protein VEGF-SEA. Black-Right-Pointing-Pointer VEGF-SEA strongly repressed the growth of murine solid sarcoma 180 (S180) tumors. Black-Right-Pointing-Pointer T cells driven by VEGF-SEA were accumulated around tumor cells bearing VEGFR by mice image model. Black-Right-Pointing-Pointer VEGF-SEA can serve as a tumor targeting agent and sequester CTLs into the tumor site. Black-Right-Pointing-Pointer The induced CTLs could release the cytokines, perforins and granzyme B to kill the tumor cells. -- Abstract: T cells are major lymphocytes in the blood and passengers across the tumor vasculature. If these T cells are retained in the tumor site, a therapeutic potential will be gained by turning them into tumor-reactive cytotoxic T lymphocytes (CTLs). A fusion protein composed of human vascular endothelial growth factor (VEGF) and staphylococcal enterotoxin A (SEA) with a D227A mutation strongly repressed the growth of murine solid sarcoma 180 (S180) tumors (control versus VEGF-SEA treated with 15 {mu}g, mean tumor weight: 1.128 g versus 0.252 g, difference = 0.876 g). CD4{sup +} and CD8{sup +} T cells driven by VEGF-SEA were accumulated around VEGFR expressing tumor cells and the induced CTLs could release the tumoricidal cytokines, such as interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha). Meanwhile, intratumoral CTLs secreted cytolytic pore-forming perforin and granzyme B proteins around tumor cells, leading to the death of tumor cells. The labeled fusion proteins were gradually targeted to the tumor site in an imaging mice model. These results show that VEGF-SEA can serve as a tumor targeting agent and sequester active infiltrating CTLs into the tumor site to kill tumor cells, and could therefore be a potential therapeutical drug for a variety of cancers.

  15. HIV-1 Nef sequence and functional compartmentalization in the gut is not due to differential cytotoxic T lymphocyte selective pressure.

    PubMed

    Lewis, Martha J; Frohnen, Patricia; Ibarrondo, F Javier; Reed, Diane; Iyer, Varun; Ng, Hwee L; Elliott, Julie; Yang, Otto O; Anton, Peter

    2013-01-01

    The gut is the largest lymphoid organ in the body and a site of active HIV-1 replication and immune surveillance. The gut is a reservoir of persistent infection in some individuals with fully suppressed plasma viremia on combination antiretroviral therapy (cART) although the cause of this persistence is unknown. The HIV-1 accessory protein Nef contributes to persistence through multiple functions including immune evasion and increasing infectivity. Previous studies showed that Nef's function is shaped by cytotoxic T lymphocyte (CTL) responses and that there are distinct populations of Nef within tissue compartments. We asked whether Nef's sequence and/or function are compartmentalized in the gut and how compartmentalization relates to local CTL immune responses. Primary nef quasispecies from paired plasma and sigmoid colon biopsies from chronically infected subjects not on therapy were sequenced and cloned into Env(-) Vpu(-) pseudotyped reporter viruses. CTL responses were mapped by IFN-γ ELISpot using expanded CD8+ cells from blood and gut with pools of overlapping peptides covering the entire HIV proteome. CD4 and MHC Class I Nef-mediated downregulation was measured by flow cytometry. Multiple tests indicated compartmentalization of nef sequences in 5 of 8 subjects. There was also compartmentalization of function with MHC Class I downregulation relatively well preserved, but significant loss of CD4 downregulation specifically by gut quasispecies in 5 of 7 subjects. There was no compartmentalization of CTL responses in 6 of 8 subjects, and the selective pressure on quasispecies correlated with the magnitude CTL response regardless of location. These results demonstrate that Nef adapts via diverse pathways to local selective pressures within gut mucosa, which may be predominated by factors other than CTL responses such as target cell availability. The finding of a functionally distinct population within gut mucosa offers some insight into how HIV-1 may persist in

  16. Cytotoxic T lymphocytes and natural killer cells display impaired cytotoxic functions and reduced activation in patients with alcoholic hepatitis.

    PubMed

    Støy, Sidsel; Dige, Anders; Sandahl, Thomas Damgaard; Laursen, Tea Lund; Buus, Christian; Hokland, Marianne; Vilstrup, Hendrik

    2015-02-15

    The dynamics and role of cytotoxic T lymphocytes (CTLs), natural killer (NK) cells, and NKT cells in the life-threatening inflammatory disease alcoholic hepatitis is largely unknown. These cells directly kill infected and damaged cells through, e.g., degranulation and interferon-γ (IFNγ) production, but cause tissue damage if overactivated. They also assist tissue repair via IL-22 production. We, therefore, aimed to investigate the frequency, functionality, and activation state of such cells in alcoholic hepatitis. We analyzed blood samples from 24 severe alcoholic hepatitis patients followed for 30 days after diagnosis. Ten healthy abstinent volunteers and 10 stable abstinent alcoholic cirrhosis patients were controls. Using flow cytometry we assessed cell frequencies, NK cell degranulation capacity following K562 cell stimulation, activation by natural killer group 2 D (NKG2D) expression, and IL-22 and IFNγ production. In alcoholic hepatitis we found a decreased frequency of CTLs compared with healthy controls (P < 0.001) and a similar trend for NK cells (P = 0.089). The NK cell degranulation capacity was reduced by 25% compared with healthy controls (P = 0.02) and by 50% compared with cirrhosis patients (P = 0.04). Accordingly, the NKG2D receptor expression was markedly decreased on NK cells, CTLs, and NKT cells (P < 0.05, all). The frequencies of IL-22-producing CTLs and NK cells were doubled compared with healthy controls (P < 0.05, all) but not different from cirrhosis patients. This exploratory study for the first time showed impaired cellular cytotoxicity and activation in alcoholic hepatitis. This is unlikely to cause hepatocyte death but may contribute toward the severe immune incompetence. The results warrant detailed and mechanistic studies.

  17. Thymic selection and adaptability of cytotoxic T lymphocyte responses in transgenic mice expressing a viral protein in the thymus

    PubMed Central

    1994-01-01

    Upon primary challenge with lymphocytic choriomeningitis virus (LCMV), H-2d (BALB/cByJ) mice mount a cytotoxic T lymphocyte (CTL) response to a single immunodominant domain of the viral nucleoprotein (NP) but no detectable response to the viral glycoprotein (GP). To manipulate this CTL response, the viral NP gene was expressed in the thymus and peripheral T lymphocytes using the murine Thy1.2 promoter. As a result, such Thy1.2-NP (H-2d) transgenic (tg) mice deleted their high-affinity anti-LCMV-NP CTL, but generated equal numbers of lower-affinity NP CTL. Further, they made an alternative anti-LCMV-GP CTL response that is not normally found in non-tg mice indicating a hierarchial control of the CTL response. Unlike the H-2d mice, H-2b (C57Bl/6J) mice normally mount a CTL response to both LCMV-GP and -NP. When the LCMV-NP was expressed using the Thy1.2 promoter in these H-2b mice, the LCMV-NP-specific CTL response was completely aborted and no CTL to new, alternative viral epitopes were generated. Dilutions of H-2b or H-2d NP peptides indicated that 3-4 logs less H-2b NP peptide was required to sensitize syngeneic target cells for CTL-specific lysis, suggesting that the differing affinities of H-2b and H-2d major histocompatibility complex molecules for their peptides likely account for the total removal of NP CTL in the H-2b mice but only partial removal in H-2d mice made to express thymic NP. Thymic grafting experiments done with thymi from newborn Thy1.2-NP tg mice show that selection processes studied in this model are of central (thymic) origin and are not caused by Thy1.2- positive LCMV-NP-expressing T lymphocytes in the periphery. PMID:7525843

  18. Mouse lymphoblasts lose their immunogenicity and susceptibility to specific cytotoxic T lymphocyte lysis during maintenance in culture.

    PubMed Central

    Leshem, B; Brass, D

    1998-01-01

    This study was undertaken to search for possible mechanisms by which T-cell lines become non-immunogenic and refractory to cellular-mediated lysis during culture. We demonstrate that mouse lymphoblasts (LB) lost their susceptibility to specific cytotoxic T lymphocyte (CTL)-mediated lysis following culture for more than 5 days in the presence interleukin-2 (IL-2), IL-7 but not IL-4. In contrast, the cultured lymphoblasts (CLB) were efficiently lysed by specific antibody and C' and by CTL in the presence of concanavalin A. In addition, CLB did not inhibit cytotoxicity against LB in a cold target competition assay, indicating that CLB and LB differ in the expression of certain surface molecules. Indeed, a significantly lower expression of H-2D class I antigen, the Fas antigen and the adhesion molecules intracelluar adhesion molecule-1 (ICAM-1) and very late activation antigen-4 (VLA-4) was observed on the CLB surface. Consequently, CLB could not form conjugates with specific CTL, a prerequisite for CTL-mediated lysis. In addition, there was a marked decrease in CLB immunogenicity: the cultured cells were unable to stimulate allogeneic spleen cells in mixed lymphocyte culture nor could they induce a cytotoxic response following their injection into allogeneic mice. The reduced immunogenicity enabled the prolonged survival of active CLB in an allogeneic host. We suggest that the extended survival in an allogeneic tumour-bearing host of cultured, hence weakly immunogenic, anti-tumour CTL, will enable them the in vivo implementation of their anti-tumour activity. PMID:9824505

  19. Uncovering subdominant cytotoxic T-lymphocyte responses in lymphocytic choriomeningitis virus-infected BALB/c mice.

    PubMed Central

    van der Most, R G; Concepcion, R J; Oseroff, C; Alexander, J; Southwood, S; Sidney, J; Chesnut, R W; Ahmed, R; Sette, A

    1997-01-01

    The cytotoxic T-lymphocyte response against lymphocytic choriomeningitis virus (LCMV) in BALB/c mice is predominantly directed against a single, Ld-restricted epitope in the viral nucleoprotein (residues 118 to 126). To investigate whether any Kd/Dd-restricted responses were activated but did not expand during the primary response, we used a BALB/c mutant, BALB/c-H-2dm2, which does not express the Ld molecule. Splenocytes from LCMV-infected BALB/c mice were transferred into irradiated BALB/c-H-2dm2 mice and rechallenged with LCMV. Thus, they were exposed to an antigenic stimulus without the involvement of the immunodominant Ld-restricted epitope. In this adoptive transfer model, the donor splenocytes protected the recipient mice against chronic LCMV infection by mounting a potent Kd- and/or Dd-restricted secondary antiviral response. Analysis of a panel of Kd binding LCMV peptides revealed that residues 283 to 291 from the viral glycoprotein (GP(283-291)) comprise a major new epitope in the adoptive transfer model. Because the donor splenocytes were first activated during the primary infection in BALB/c mice, the GP(283-291) epitope is a subdominant epitope in BALB/c mice that becomes dominant after rechallenge in BALB/c-H-2dm2 mice. This study makes two points. First, it shows that subdominant CTL responses can be protective, and second, it provides a general experimental approach for uncovering subdominant CTL responses in vivo. This strategy can be used to identify subdominant T-cell responses in other systems. PMID:9188577

  20. Primary pulmonary cytotoxic T lymphocytes induced by immunization with a vaccinia virus recombinant expressing influenza A virus nucleoprotein peptide do not protect mice against challenge.

    PubMed Central

    Lawson, C M; Bennink, J R; Restifo, N P; Yewdell, J W; Murphy, B R

    1994-01-01

    The nucleoprotein (NP) of influenza A virus is the dominant antigen recognized by influenza virus-specific cytotoxic T lymphocytes (CTLs), and adoptive transfer of NP-specific CTLs protects mice from influenza A virus infection. BALB/c mouse cells (H-2d) recognize a single Kd-restricted CTL epitope of NP consisting of amino acids 147 to 155. In the present study, mice were immunized with various vaccinia virus recombinant viruses to examine the effect of the induction of primary pulmonary CTLs on resistance to challenge with influenza A/Puerto Rico/8/34 virus. The minigene ESNP(147-155)-VAC construct, composed of a signal sequence from the adenovirus E3/19K glycoprotein (designated ES) and expressing the 9-amino-acid NP natural determinant (amino acids 147 to 155) preceded by an alanine residue, a similar minigene NP(Met 147-155)-VAC lacking ES, and a full-length NP-VAC recombinant of influenza virus were analyzed. The two minigene NP-VAC recombinants induced a greater primary pulmonary CTL response than the full-length NP-VAC recombinant. However, NP-specific CTLs induced by immunization with ESNP(147-155)-VAC did not decrease peak virus titer or accelerate clearance of virus in the lungs of mice challenged intranasally with A/PR/8/34. Furthermore, NP-specific CTLs induced by immunization did not protect mice challenged intranasally with a lethal dose of A/PR/8/34. Sequence analysis of the NP CTL epitope of A/PR/8/34 challenge virus obtained from lungs after 8 days of replication in ESNP(147-155)-VAC-immunized mice showed identity with that of the input virus, demonstrating that an escape mutant had not emerged during replication in vivo. Thus, in contrast to adoptively transferred CTLs, pulmonary NP-specific CTLs induced by recombinant vaccinia virus immunization do not have protective in vivo antiviral activity against influenza virus infection. PMID:7514677

  1. Association of Cytotoxic T-Lymphocyte Antigen 4 (CTLA4) and Thyroglobulin (TG) Genetic Variants with Autoimmune Hypothyroidism.

    PubMed

    Patel, Hinal; Mansuri, Mohmmad Shoab; Singh, Mala; Begum, Rasheedunnisa; Shastri, Minal; Misra, Ambikanandan

    2016-01-01

    Autoimmune hypothyroidism is known to be caused by immune responses related to the thyroid gland and its immunological feature includes presence of autoimmune antibodies. Therefore the aim was to analyze presence of anti-TPO antibodies in hypothyroidism patients in Gujarat. Cytotoxic T-Lymphocyte Antigen 4 (CTLA4) is one of the susceptibility genes for various autoimmune diseases. Hence, exon1 +49A/G and 3'UTR CT60A/G single nucleotide polymorphisms (SNPs) in CTLA4 and its mRNA expression levels were investigated in autoimmune hypothyroidism patients. Thyroglobulin (TG) is known to be associated with autoimmune thyroid disorders and thus exon 33 (E33) SNP in TG was investigated. We analyzed the presence of anti-TPO antibodies in the plasma samples of 84 hypothyroidism patients and 62 controls by ELISA. PCR-RFLP technique was used for genotyping of polymorphisms. sCTLA4 and flCTLA4 mRNA expression levels were assessed by real time PCR. 59.52% of hypothyroid patients had anti-TPO antibodies in their circulation. The genotype and allele frequencies differed significantly for +49A/G (p = 0.0004 for +49AG, p = 0.0019 for +49GG & p = 0.0004 for allele), CT60 (p = 0.0110 for CT60AG, p = 0.0005 for CT60GG & p<0.0001 for allele) and TG E33 (p = 0.0003 for E33TC p<0.0001 for E33CC& p<0.0001 for allele) SNPs between patients and controls. Patients had significantly decreased mRNA levels of both sCTLA4 (p = 0.0017) and flCTLA4 (p<0.0001) compared to controls. +49A/G and CT60 polymorphisms of CTLA4 were in moderate linkage disequilibrium. Logistic regression analysis indicated significant association of CT49A/G, CT60A/G and TG exon 33 polymorphisms with susceptibility to autoimmune hypothyroidism when adjusted for age and gender. Our results suggest +49A/G and CT60 polymorphism of CTLA4 and E33 polymorphism of TG may be genetic risk factors for autoimmune hypothyroidism susceptibility and down regulation of both forms of CTLA4 advocates the crucial role of CTLA4 in pathogenesis

  2. Hierarchy among multiple H-2b-restricted cytotoxic T-lymphocyte epitopes within simian virus 40 T antigen.

    PubMed Central

    Mylin, L M; Bonneau, R H; Lippolis, J D; Tevethia, S S

    1995-01-01

    Simian virus 40 large tumor (T) antigen contains three H-2Db-restricted (I, II/III, and V) and one H-2Kb-restricted (IV) cytotoxic T lymphocyte (CTL) epitopes. We demonstrate that a hierarchy exists among these CTL epitopes, since vigorous CTL responses against epitopes I, II/III, and IV are detected following immunization of H-2b mice with syngeneic, T-antigen-expressing cells. By contrast, a weak CTL response against the H-2Db-restricted epitope V was detected only following immunization of H-2b mice with epitope loss variant B6/K-3,1,4 cells, which have lost expression of CTL epitopes I, II/III, and IV. Limiting-dilution analysis confirmed that the lack of epitope V-specific CTL activity in bulk culture splenocytes correlated with inefficient expansion and priming of epitope V-specific CTL precursors in vivo. We examined whether defined genetic alterations of T antigen might improve processing and presentation of epitope V to the epitope V-specific CTL clone Y-5 in vitro and/or overcome the recessive nature of epitope V in vivo. Deletion of the H-2Db-restricted epitopes I and II/III from T antigen did not increase target cell lysis by epitope V-specific CTL clones in vitro. The amino acid sequence SMIKNLEYM, which species an optimized H-2Db binding motif and was found to induce CTL in H-2b mice, did not further reduce epitope V presentation in vitro when inserted within T antigen. Epitope V-containing T-antigen derivatives which retained epitopes I and II/III or epitope IV did not induce epitope V-specific CTL in vivo: T-antigen derivatives in which epitope V replaced epitope I failed to induce epitope V-specific CTL. Recognition of epitope V-H-2Db complexes by multiple independently derived epitope V-specific CTL clones was rapidly and dramatically reduced by incubation of target cells in the presence of brefeldin A compared with the recognition of the other T-antigen CTL epitopes by epitope specific CTL, suggesting that the epitope V-H-2Db complexes either are

  3. Cytotoxic T lymphocyte antigen 4 (CTLA4) gene polymorphism with bladder cancer risk in North Indian population.

    PubMed

    Jaiswal, Praveen Kumar; Singh, Vibha; Mittal, Rama Devi

    2014-02-01

    Cytotoxic T Lymphocyte antigen 4 (CTLA4) is a potent immunoregulatory molecule that suppresses antitumor response by down-regulating T cell activation. We examined candidate disease-susceptibility single nucleotide polymorphism (SNPs) of CTLA4 at +49A/G, CT60A/G and -318C/T genes in bladder cancer (BC) patients of North Indian population. Histopathologically confirmed 200 patients of BC and 200 unrelated, healthy controls of similar ethnicity were genotyped by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) and amplification refractory mutation specific (PCR-ARMS) methods. In present study SNP CTLA4 +49A/G, variant genotype showed 3.74-fold risks for BC. While looking at G allele carrier level, risk for BC was high (OR = 1.54). The risk for BC was also evident in case G allele (OR = 1.58). CTLA4 CT60A/G gene polymorphism variant genotype showed 1.36-fold risks for BC. While at G allele carrier and with variant G allele it showed significantly reduced risk for BC. CTLA4 +49A/G genotype exhibited 1.57-fold risks with smoking in BC patients in homozygous mutant condition. In silico analysis further supports the results of SNP at CTLA4 +49A/G and CTLA4 CT60A/G. None of the above SNPs of CTLA4 demonstrated association with tumor stage/grade for BC severity and progression. BCG immunotherapy had no impact on CTLA4 gene polymorphism revealing no significant association. Haplotype GAC showed high risk for BC while other haplotype AGT showed reduced risk for BC. Our results indicated that genetic variations in CTLA4 gene (+49A/G, CT60A/G) play role in susceptibility to BC. Haplotype GAC showed high risk for BC. An association study utilizing a larger sample size and different ethnicity warrant further investigation through replication and advance techniques.

  4. Human CD8+ herpes simplex virus-specific cytotoxic T-lymphocyte clones recognize diverse virion protein antigens.

    PubMed Central

    Tigges, M A; Koelle, D; Hartog, K; Sekulovich, R E; Corey, L; Burke, R L

    1992-01-01

    The role of the HLA class I-restricted, CD8+, herpes simplex virus (HSV)-specific cytotoxic T lymphocytes (CTL) in the control of human HSV infections is controversial because previous reports suggest that a substantial portion of the antigen-specific lytic response is mediated by CD4+ cells. To address this question directly, we isolated HSV-specific CD8+ CTL clones from a patient with recurrent genital herpes. These CTL were cloned by coculturing responder peripheral blood mononuclear cells (PBMC) with phytohemagglutinin-stimulated PBMC that had been infected with live HSV-2 and then irradiated prior to the addition of responder cells. After 1 week, CTL were cloned by limiting dilution using phytohemagglutinin stimulation and allogeneic feeder PBMC. Seven clones were isolated; all seven clones were CD8+ CD4- CD3+ DRbright, six lysed only HSV-2-infected targets, and one lysed both HSV-1- and HSV-2-infected targets. Antigen presentation was restricted by two to three different HLA class I loci. To determine the antigens recognized by these HSV-specific CTL, target cells were infected with HSV in the presence of acyclovir, 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole, or cycloheximide in a series of drug block/release protocols to limit the repertoire of viral gene expression to select transcriptional classes. Five of the clones exhibited a different pattern of cytotoxicity, suggesting that each recognized a distinct HSV antigen. One of the clones appears to be directed against an immediate-early antigen; six of the clones recognize virion proteins. Five of these clones recognized internal virion proteins that could be introduced into target cells by HSV infection in the absence of virus gene expression. Antigen specificity was further tested by using vaccinia virus vectors that express glycoproteins gD2 and gB2 or the tegument protein VP16. One clone lysed vaccinia virus/gD2-infected target cells; the remaining clones did not recognize any of these gene

  5. [Association between cytotoxic T lymphocyte protein-4 polymorphisms and non-Hodgkin's lymphoma risk: a meta-analysis].

    PubMed

    Yi, Biyu; Pei, Yijin; Wang, Chun; Jiang, Yang

    2016-08-01

    Objective To investigate the potential association of cytotoxic T lymphocyte associated protein 4 (CTLA4) polymorphisms with non-Hodgkin's lymphoma (NHL) risk. Methods Two reviewers independently searched the PubMed, MEDLINE, China National Knowledge Infrastructure (CNKI), Chinese WanFang databases and Database of Chinese Scientific and Technical Periodicals (VIP) for relevant studies from January 1, 1990 to May 25, 2016. Odds ratios (OR) with 95% confidence intervals (CI) for CTLA4 polymorphism and HNL risk were used to evaluate the strength of association. Meta-analysis was performed using SATA (v12.0) software. Results A total of 6 case-control studies concerning the CTLA4 +49A/G, -318T/C, and CT60A/G polymorphisms were included in the meta-analysis. The polymorphisms of the three alleles were not associated with genetic susceptibility to NHL (PZ>0.05 or 95%CI contains 1). In the subgroup analysis of CTLA4 +49A/G gene polymorphism, we found that AA was a risk factor for mixed type lymphoma (AA vs GG: OR=4.181, 95%CI: 1.362-12.833; AA+AG vs GG: OR=3.217, 95%CI: 1.055-9.810; AA vs AG+GG: OR=2.827, 95%CI: 1.345-5.940), but was a protect factor for B cell lymphoma (AA vs GG: OR=0.465, 95%CI: 0.251-0.863; AA vs AG+GG: OR=0.534, 95%CI: 0.362-0.788); AA was a risk factor in Italians (AA vs GG: OR=4.181, 95%CI: 1.362-12.833; AA+AG vs GG: OR=3.217, 95%CI: 1.055-9.810; AA vs AG+GG: OR=2.827, 95%CI: 1.345-5.940), but was a protect factor in Chinese (AA vs GG: OR=0.643, 95%CI: 0.417-0.992; AA vs AG+GG, OR=0.601, 95%CI: 0.395-0.913). Conclusion This meta-analysis suggests that the polymorphisms of the three alleles are not associated with genetic susceptibility to NHL. PMID:27412943

  6. T helper cells in cytotoxic T lymphocyte development: role of L3T4(+)-dependent and -independent T helper cell pathways in virus-specific and alloreactive cytotoxic T lymphocyte responses.

    PubMed

    Ciavarra, R P

    1990-02-01

    I have compared the requirements for T helper (Th) cell function during the generation of virus-specific and alloreactive cytotoxic thymus (T)-derived lymphocyte (CTL) responses. Restimulation of vesicular stomatitis virus (VSV)-immune T cells (VSV memory CTLs) with VSV-infected stimulators resulted in the generation of class I-restricted, VSV-specific CTLs. Progression of VSV memory CTLs (Lyt-1-2+) into VSV-specific CTLs required inductive signals derived from VSV-induced, Lyt-1+2- Th cells because: (i) cultures depleted by negative selection of Lyt-1+ T cells failed to generate CTLs; (ii) titration of VSV memory CTLs into a limiting dilution (LD) microculture system depleted of Th cells generated curves which were not consistent with a single limiting cell type; (iii) LD analysis of VSV memory CTLs did produce single-hit curves in the presence of Lyt-1+2- T cells sensitized against VSV; and (iv) monoclonal anti-L3T4 antibody completely abrogated CTL generation against VSV. Similar results were also obtained with Sendai virus (SV), a member of the paramyxovirus family. The notion that a class II-restricted, L3T4+ Th cell plays an obligatory role in the generation of CTLs against these viruses is also supported by the observation that purified T cell lymphoblasts (class II antigen negative) failed to function as antigen-presenting cells for CTL responses against VSV and SV. T cell lymphoblasts were efficiently lysed by class I-restricted, anti-VSV and -SV CTLs, indicating that activated T cells expressed the appropriate viral peptides for CTL recognition. Furthermore, heterogeneity in the VSV-induced Th cell population was detected by LD analysis, suggesting that at least two types of Th cells were required for the generation of an anti-VSV CTL response. VSV-induced Th cell function could not simply be replaced by exogenous IL-2 because this lymphokine induced cytotoxic cells that had the characteristics of lymphokine-activated killer (LAK) cells and not anti

  7. Cytotoxic T lymphocyte antigen 4 decreases humoral and cellular immunity by adenovirus to enhance target GFP gene transfer in C57BL/6 mice.

    PubMed

    Bai, Dou; Zhu, Wei; Zhang, Yu; Long, Ling; Zhu, Naishuo

    2015-01-01

    Adenoviruses (Ad) are once potential and promising vectors for gene delivery, but the immunogenicity attenuates its transfer efficiency. Cytotoxic T lymphocyte antigen 4 (CTLA-4) can inhibit T cell immunity. Thus, we aimed to study the effect of CTLA-4 in the process of Ad-mediated gene transfer. The C57BL/6 mice were injected by Ad vectors at twice, and CTLA-4 was administrated after the first Ad injection. Then, the CD3(+)CD4(+) T cells and circulating levels of IL-2, IL-4, and anti-Ad IgG were decreased by CTLA-4, while Ad generated immune responses. The green fluorescence protein (GFP) expressions of tissues were enhanced by CTLA-4 till injection of Ad at twice. Our results indicate that CTLA-4 can inhibit humoral and cellular immunity by adenovirus generation to enhance GFP delivery, and provide a potential way to assist in Ad-mediated gene transfer.

  8. Spontaneous human squamous cell carcinomas are killed by a human cytotoxic T lymphocyte clone recognizing a wild-type p53-derived peptide.

    PubMed

    Röpke, M; Hald, J; Guldberg, P; Zeuthen, J; Nørgaard, L; Fugger, L; Svejgaard, A; Van der Burg, S; Nijman, H W; Melief, C J; Claesson, M H

    1996-12-10

    A cytotoxic T lymphocyte (CTL) clone generated in vitro from the peripheral blood of a healthy HLA-A2-positive individual against a synthetic p53 protein-derived wild-type peptide (L9V) was shown to kill squamous carcinoma cell lines derived from two head and neck carcinomas, which expressed mutant p53 genes, in a L9V/HLA-A2 specific and restricted fashion. Thus, the normal tolerance against endogenously processed p53 protein-derived self-epitopes can be broken by peptide-specific in vitro priming. p53 protein-derived wild-type peptides might thus represent tumor associated target molecules for immunotherapeutical approaches. PMID:8962118

  9. Activation of tumor antigen-specific cytotoxic T lymphocytes (CTLs) by human dendritic cells infected with an attenuated influenza A virus expressing a CTL epitope derived from the HER-2/neu proto-oncogene.

    PubMed

    Efferson, Clay L; Schickli, Jeanne; Ko, Byung Kyum; Kawano, Kouichiro; Mouzi, Sara; Palese, Peter; García-Sastre, Adolfo; Ioannides, Constantin G

    2003-07-01

    The development of cancer vaccines requires approaches to induce expansion and functional differentiation of tumor antigen-specific cytotoxic T lymphocyte (CTL) effectors which posses cytolytic capability and produce cytokines. Efficient induction of such cells is hindered by the poor immunogenicity of tumor antigens and by the poor transduction efficiency of dendritic cells (DCs) with current nonreplicating vectors. We have investigated the use of influenza A virus, a potent viral inducer of CTLs, as a vector expressing the immunodominant HER-2 CTL epitope KIF (E75). For this purpose, an attenuated influenza A/PR8/34 virus with a truncated nonstructural (NS1) gene was generated containing the E75 epitope in its neuraminidase protein (KIF-NS virus). Stimulation of peripheral blood mononuclear cells from healthy donors and of tumor-associated lymphocytes from ovarian and breast cancer patients with DCs infected with KIF-NS virus (KIF-NS DC) induced CTLs that specifically recognized the peptide KIF and HER-2-expressing tumors in cytotoxicity assays and secreted gamma interferon (IFN-gamma) and interleukin-2 at recall with peptide. Priming with KIF-NS DCs increased the number of E75(+) CD45RO(+) cells by more than 10-fold compared to nonstimulated cells. In addition, KIF-NS virus induced high levels of IFN-alpha in DCs. This is the first report demonstrating induction of human epitope-specific CTLs against a tumor-associated antigen with a live attenuated recombinant influenza virus vector. Such vectors may provide a novel approach for tumor antigen delivery, lymphocyte activation, and differentiation in human cancer vaccine development.

  10. Streptococcal preparation OK-432 promotes the capacity of dendritic cells (DCs) to prime carcinoembryonic antigen (CEA)-specific cytotoxic T lymphocyte responses induced with genetically modified DCs that express CEA.

    PubMed

    Ojima, Toshiyasu; Iwahashi, Makoto; Nakamura, Masaki; Matsuda, Kenji; Nakamori, Mikihito; Ueda, Kentaro; Naka, Teiji; Katsuda, Masahiro; Miyazawa, Motoki; Iida, Takeshi; Yamaue, Hiroki

    2008-02-01

    Cancer immunotherapy using dendritic cells (DCs) adenovirally transduced with the whole tumor-associated antigen (TAA) gene is an effective approach. Streptococcal preparation OK-432 is useful for stimulating DCs in terms of maturation. In this study, we established carcinoembryonic antigen (CEA)-specific cytotoxic T lymphocytes (CTLs) using in vitro stimulation with adenovirally modified human DCs that express CEA. We investigated whether OK-432 stimulation could be more effective in inducing CEA-specific CTLs compared with other typical stimuli. DCs adenovirally transduced with the CEA gene were cultured under various conditions with tumor necrosis factor (TNF)-alpha, lipopolysaccharide (LPS), or OK-432. A cytotoxicity assay using peripheral blood mononuclear cell (PBMC)-derived CTLs was performed in a 4 h-51Cr release assay. OK-432 stimulated immature DCs to acquire a mature phenotype and to produce significant amounts of T-helper 1 cytokines. In all groups (immature DCs, TNF-alpha/DCs, LPS/DCs, OK-432/DCs), CEA-specific CTLs were generated. OK-432-stimulated DCs (HLA-A24) induced the most potent cytotoxic activity against CEA-expressing targets (A24) but not against controls. OK-432/DCs were able to induce markedly potent CTLs specific to target cells pulsed with CEA652 peptide (HLA-A24-restricted peptide), although others failed to induce potent CTLs. In conclusion, the CTL induction protocol using adenovirally modified DCs that express CEA after maturation with OK-432 showed a potent antitumor activity against CEA-expressing target cells, and is therefore promising for clinical applications as a cancer vaccine therapy.

  11. Propanil Exposure Induces Delayed but Sustained Abrogation of Cell-Mediated Immunity through Direct Interference with Cytotoxic T-Lymphocyte Effectors

    PubMed Central

    Sheil, James M.; Frankenberry, Marc A.; Schell, Todd D.; Brundage, Kathleen M.; Barnett, John B.

    2006-01-01

    The postemergent herbicide propanil (PRN; also known as 3,4-dichloropropionanilide) is used on rice and wheat crops and has well-known immunotoxic effects on various compartments of the immune system, including T-helper lymphocytes, B lymphocytes, and macrophages. It is unclear, however, whether PRN also adversely affects cytotoxic T lymphocytes (CTLs), the primary (1°) effectors of cell-mediated immunity. In this study we examined both the direct and indirect effects of PRN exposure on CTL activation and effector cell function to gauge its likely impact on cell-mediated immunity. Initial experiments addressed whether PRN alters the class I major histocompatibility complex (MHC) pathway for antigen processing and presentation by antigen-presenting cells (APCs), thereby indirectly affecting effector function. These experiments demonstrated that PRN does not impair the activation of CTLs by PRN-treated APCs. Subsequent experiments addressed whether PRN treatment of CTLs directly inhibits their activation and revealed that 1° alloreactive CTLs exposed to PRN are unimpaired in their proliferative response and only marginally inhibited in their lytic activity. Surprisingly, secondary stimulation of these alloreactive CTL effectors, however, even in the absence of further PRN exposure, resulted in complete abrogation of CTL lytic function and a delayed but significant long-term effect on CTL responsiveness. These findings may have important implications for the diagnosis and clinical management of anomalies of cell-mediated immunity resulting from environmental exposure to various herbicides and other pesticides. PMID:16835059

  12. Dendritic Cell-Secreted Cytotoxic T-Lymphocyte-Associated Protein-4 Regulates the T-cell Response by Downmodulating Bystander Surface B7.

    PubMed

    Halpert, Matthew M; Konduri, Vanaja; Liang, Dan; Chen, Yunyu; Wing, James B; Paust, Silke; Levitt, Jonathan M; Decker, William K

    2016-05-15

    The remarkable functional plasticity of professional antigen-presenting cells (APCs) allows the adaptive immune system to respond specifically to an incredibly diverse array of potential pathogenic insults; nonetheless, the specific molecular effectors and mechanisms that underpin this plasticity remain poorly characterized. Cytotoxic T-lymphocyte-associated protein-4 (CTLA-4), the target of the blockbuster cancer immunotherapeutic ipilimumab, is one of the most well-known and well-studied members of the B7 superfamily and negatively regulates T cell responses by a variety of known mechanisms. Although CTLA-4 is thought to be expressed almost exclusively among lymphoid lineage hematopoietic cells, a few reports have indicated that nonlymphoid APCs can also express the CTLA-4 mRNA transcript and that transcript levels can be regulated by external stimuli. In this study, we substantially build upon these critical observations, definitively demonstrating that mature myeloid lineage dendritic cells (DC) express significant levels of intracellular CTLA-4 that they constitutively secrete in microvesicular structures. CTLA-4(+) microvesicles can competitively bind B7 costimulatory molecules on bystander DC, resulting in downregulation of B7 surface expression with significant functional consequences for downstream CD8(+) T-cell responses. Hence, the data indicate a previously unknown role for DC-derived CTLA-4 in immune cell functional plasticity and have significant implication for the design and implementation of immunomodulatory strategies intended to treat cancer and infectious disease. PMID:26979751

  13. Infection with Cytotoxic T-Lymphocyte Escape Mutants Results in Increased Mortality and Growth Retardation in Mice Infected with a Neurotropic Coronavirus

    PubMed Central

    Pewe, Lecia; Xue, Shurong; Perlman, Stanley

    1998-01-01

    C57BL/6 mice infected with mouse hepatitis virus strain JHM (MHV-JHM) develop a chronic demyelinating encephalomyelitis several weeks after inoculation. Previously, we showed that mutations in the immunodominant CD8 T-cell epitope (S-510-518) could be detected in nearly all samples of RNA and virus isolated from these mice. These mutations abrogated recognition by T cells harvested from the central nervous systems of infected mice in direct ex vivo cytotoxicity assays. These results suggested that cytotoxic T-lymphocyte (CTL) escape mutants contributed to virus amplification and the development of clinical disease in mice infected with wild-type virus. In the present study, the importance of these mutations was further evaluated by infecting naive mice with MHV-JHM variants isolated from infected mice and in which epitope S-510-518 was mutated. Compared to mice infected with wild-type virus, variant virus-infected animals showed higher mortality and morbidity manifested by decreased weight gain and neurological signs. Although a delay in the kinetics of virus clearance has been demonstrated in previous studies of CTL escape mutants, this is the first illustration of significant changes in clinical disease resulting from infection with viruses able to evade the CD8 T-cell immune response. PMID:9621053

  14. Major histocompatibility complex class I-specific and -restricted killing of beta 2-microglobulin-deficient cells by CD8+ cytotoxic T lymphocytes.

    PubMed Central

    Glas, R; Franksson, L; Ohlén, C; Höglund, P; Koller, B; Ljunggren, H G; Kärre, K

    1992-01-01

    Cytotoxic T lymphocytes (CTLs) recognize major histocompatibility complex (MHC) class I molecules, normally composed of a heavy chain, a beta 2-microglobulin (beta 2m), and peptide antigens. beta 2m is considered essential for the assembly and intracellular transport of MHC class I molecules as well as their peptide presentation to CTLs. Contrary to this dogma, we now report the generation of allospecific and restricted CD8+ and TCR alpha beta+ CTLs (where TCR is T-cell receptor) capable of killing beta 2m-deficient cells. Such CTLs were obtained by priming mice with live allogeneic beta 2m- spleen cells or mutant lymphoma cells producing MHC class I protein but no detectable beta 2m. Although both beta 2m- and beta 2m-expressing lymphoma cells were rejected in allogeneic mice, only the former were efficient inducers of CTLs recognizing beta 2m- cells. These CTLs were MHC class I (H-2Kb or Db)-specific and CD8-dependent and did not require serum as a source of external beta 2m in the culture. They could be induced across major and minor histocompatibility barriers. The H-2-restricted CTLs generated in the latter case failed to kill the antigen-processing-deficient target RMA-S cells. The results show that MHC class I heavy chains in beta 2m- cells can be transported to the cell surface and act as antigens or antigen-presenting molecules to allospecific and MHC-restricted CTLs. PMID:1454824

  15. Cloning and large-scale expansion of epitope-specific equine cytotoxic T lymphocytes using an anti-equine CD3 monoclonal antibody and human recombinant IL-2

    PubMed Central

    Mealey, Robert H.; Littke, Matt H.; Leib, Steven R.; Davis, William C.; McGuire, Travis C.

    2007-01-01

    Cytotoxic T lymphocytes are involved in controlling intracellular pathogens in many species, including horses. Particularly, CTL are critical for the control of equine infectious anemia virus (EIAV), a lentivirus that infects horses world-wide. In humans and animal models, CTL clones are valuable for evaluating the fine specificity of epitope recognition, and for adoptive immunotherapy against infectious and neoplastic diseases. Cloned CTL would be equally useful for similar studies in the horse. Here we present the first analysis of a method to generate equine CTL clones. Peripheral blood mononuclear cells were obtained from an EIAV-infected horse and stimulated with the EIAV Rev-QW11 peptide. Sorted CD8+ T cells were cloned by limiting dilution, and expanded without further antigen addition using irradiated PBMC, anti-equine CD3, and human recombinant IL-2. Clones could be frozen and thawed without detrimental effects, and could be subsequently expanded to numbers exceeding 2 × 109 cells. Flow cytometry of expanded clones confirmed the CD3+/CD8+ phenotype, and chromium release assays confirmed CTL activity. Finally, sequencing TCR beta chain genes confirmed clonality. Our results provide a reliable means to generate large numbers of epitope-specific equine CTL clones that are suitable for use in downstream applications, including functional assays and adoptive transfer studies. PMID:17498813

  16. ADAP and SKAP55 deficiency suppresses PD-1 expression in CD8+ cytotoxic T lymphocytes for enhanced anti-tumor immunotherapy

    PubMed Central

    Li, Chunyang; Li, Weiyun; Xiao, Jun; Jiao, Shaozhuo; Teng, Fei; Xue, Shengjie; Zhang, Chi; Sheng, Chun; Leng, Qibin; Rudd, Christopher E; Wei, Bin; Wang, Hongyan

    2015-01-01

    PD-1 negatively regulates CD8+ cytotoxic T lymphocytes (CTL) cytotoxicity and anti-tumor immunity. However, it is not fully understood how PD-1 expression on CD8+ CTL is regulated during anti-tumor immunotherapy. In this study, we have identified that the ADAP-SKAP55 signaling module reduced CD8+ CTL cytotoxicity and enhanced PD-1 expression in a Fyn-, Ca2+-, and NFATc1-dependent manner. In DC vaccine-based tumor prevention and therapeutic models, knockout of SKAP55 or ADAP showed a heightened protection from tumor formation or metastases in mice and reduced PD-1 expression in CD8+ effector cells. Interestingly, CTLA-4 levels and the percentages of tumor infiltrating CD4+Foxp3+ Tregs remained unchanged. Furthermore, adoptive transfer of SKAP55-deficient or ADAP-deficient CD8+ CTLs significantly blocked tumor growth and increased anti-tumor immunity. Pretreatment of wild-type CD8+ CTLs with the NFATc1 inhibitor CsA could also downregulate PD-1 expression and enhance anti-tumor therapeutic efficacy. Together, we propose that targeting the unrecognized ADAP-SKAP55-NFATc1-PD-1 pathway might increase efficacy of anti-tumor immunotherapy. PMID:25851535

  17. Carthamus tinctorius Enhances the Antitumor Activity of Dendritic Cell Vaccines via Polarization toward Th1 Cytokines and Increase of Cytotoxic T Lymphocytes

    PubMed Central

    Chang, Jia-Ming; Hung, Le-Mei; Chyan, Yau-Jan; Cheng, Chun-Ming; Wu, Rey-Yuh

    2011-01-01

    Carthamus tinctorius (CT), also named safflower, is a traditional Chinese medicine widely used to improve blood circulation. CT also has been studied for its antitumor activity in certain cancers. To investigate the effects of CT on the dendritic cell (DC)-based vaccine in cancer treatment, cytokine secretion of mouse splenic T lymphocytes and the maturation of DCs in response to CT were analyzed. To assess the antitumor activity of CT extract on mouse CD117+ (c-kit)-derived DCs pulsed with JC mammal tumor antigens, the JC tumor was challenged by the CT-treated DC vaccine in vivo. CT stimulated IFN-γ and IL-10 secretion of splenic T lymphocytes and enhanced the maturation of DCs by enhancing immunological molecule expression. When DC vaccine was pulsed with tumor antigens along with CT extract, the levels of TNF-α and IL-1β were dramatically increased with a dose-dependent response and more immunologic and co-stimulatory molecules were expressed on the DC surface. In addition, CT-treated tumor lysate-pulsed DC vaccine reduced the tumor weight in tumor-bearing mice by 15.3% more than tumor lysate-pulsed DC vaccine without CT treatment. CT polarized cytokine secretion toward the Th1 pathway and also increased the population of cytotoxic T lymphocytes ex vivo. In conclusion, CT activates DCs might promote the recognition of antigens and facilitate antigen presentation to Th1 immune responses. PMID:19001481

  18. Generation of leukemia-reactive cytotoxic T lymphocytes from HLA-identical donors of patients with chronic myeloid leukemia using modifications of a limiting dilution assay.

    PubMed

    Smit, W M; Rijnbeek, M; van Bergen, C A; Willemze, R; Falkenburg, J H

    1998-03-01

    Donor leukocyte transfusions (DLT) have an anti-leukemic effect in most patients with a relapse of chronic myeloid leukemia (CML) after allogeneic stem cell transplantation. However, DLT are often complicated by graft-versus-host disease. Selection of donor lymphocytes with a relative specificity for leukemic cells is desirable. The generation of leukemia-reactive cytotoxic T lymphocyte (CTL) responses between HLA-identical donors and patients in bulk cultures showed major variations, and false negative results were observed. In a modification of a limiting dilution analysis (LDA) two-fold serial dilutions of HLA-identical donor mononuclear cells (MNC) were cultured in the presence of CML cells. The anti-leukemic CTL precursor frequencies in these donors varied between <1 and 9 per 106 MNC. HLA-restricted CD4+ or CD8+ lymphocytes as well as MHC non-restricted gammadelta T cells were responsible for the anti-leukemic responses. A positive correlation between cytotoxicity in the various wells after 3, 4 and 5 weeks of culture could be found. The LDA may be superior to bulk cultures in selecting stable immune responses and in separating multiple different anti-leukemic T cell responses in each donor-patient combination.

  19. Adoptive transfer of cytotoxic T lymphocytes induced by CD86-transfected tumor cells suppresses multi-organ metastases of C1300 neuroblastoma in mice.

    PubMed

    Enomoto, A; Kato, K; Yagita, H; Okumura, K

    1997-06-01

    In this study, we examined the therapeutic antitumor effect of cytotoxic T lymphocytes (CTL) generated against CD86-transfected mouse neuroblastoma C1300. We first generated the transfectant, CD86 + C1300, expressing a high level of mouse CD86 on the cell surface. While CD86 + C1300 cells were rejected in syngeneic A/J mice when inoculated subcutaneously, neither vaccination nor any therapeutic antitumor effect was obtained, implying that C1300 may be a poorly immunogenic tumor. However, in vitro stimulation of splenocytes from either C1300-bearing or CD86 + C1300-rejecting mice with CD86 + C1300 cells resulted in remarkable CTL activity against C1300 cells. The CTL activity induced by CD86 + C1300 was mediated by T cell receptor/CD3 and CD8 and was further enhanced by the addition of interleukin-2. Intravenous inoculation of C1300 cells led to multiple organ metastases including the liver, lung, kidney, ovary, lymph node and bone marrow. To examine the therapeutic effect of CTL in this metastasis model, CTL induced by parental or CD86 + C1300 cells were administrated into C1300-bearing mice. Adoptive transfer of CD86 + C1300-induced CTL resulted in marked elimination of multi-organ metastases and prolonged survival in almost all mice, 70% of which survived indefinitely. These results indicate that adoptive transfer of CTL induced by CD86-transfected tumor cells in vitro would be effective and useful for tumor immunotherapy against poorly immunogenic tumors.

  20. Artificial antigen-presenting cells expressing AFP158-166 peptide and interleukin-15 activate AFP-specific cytotoxic T lymphocytes

    PubMed Central

    Sun, Longhao; Guo, Hao; Jiang, Ruoyu; Lu, Li; Liu, Tong; Zhang, Zhixiang; He, Xianghui

    2016-01-01

    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. The expression of AFP158-166-HLA-A*02:01 complex, CD80, CD86, and interleukin (IL)-15 in BA15 cells was assessed. The efficiency of BA15 at generating AFP-specific CTLs and the specific cytotoxicity of CTLs against AFP+ cells were also determined. BA15 cells expressed high levels of AFP158-166 peptide, HLA-A2, CD80, CD86, and IL-15. BA15 cells also exhibited higher efficiency in generating AFP-specific CTLs than did dendritic cells. These CTLs had greater cytotoxicity against AFP+ hepatocellular carcinoma cells than did CTLs obtained from dendritic cells in vitro and in vivo. Our novel aAPC system could provide a robust platform for the generation of functional AFP-specific CTLs for adoptive immunotherapy of hepatocellular carcinoma. PMID:27007051

  1. Interferon-gamma Inhibits Melanogenesis and Induces Apoptosis in Melanocytes: A Pivotal Role of CD8+ Cytotoxic T Lymphocytes in Vitiligo.

    PubMed

    Yang, Lili; Wei, Yi; Sun, Yue; Shi, Weimin; Yang, Ji; Zhu, Lubing; Li, Ming

    2015-07-01

    Increased expression of the cytokine interferon (IFN)-γ plays a pivotal role in vitiligo-induced depigmentation. However, the major source of IFN-γ in vitiligo patients and the mechanisms underlying melanocyte destruction are unknown. In this study, a large number of skin infiltrating IFN-γ+ cells and CD8+ T cells were detected in progressive vitiligo. Among the peripheral blood mononuclear cells (PBMCs) of vitiligo patients, CD8+ cytotoxic T lymphocytes (CTLs) that express IFN-γ exhibited significant expansion, which suggests that activated CTLs are the main source of increased IFN-γ in progressive vitiligo. An in vitro analysis demonstrated that IFN-γ inhibits melanogenesis in primary cultured human melanocytes by altering melanogenic enzyme mRNA expression and, more importantly, that IFN-γ directly induces melanocyte apoptosis. Our data indicate that vitiligo pathophysiology may be linked to globally activated CD8+ CTL subpopulations, which produce increased IFN-γ and induce melanocyte dysfunction and apoptosis.

  2. Association of cytotoxic T-lymphocyte antigen 4 genetic polymorphism, hepatitis C viral infection and B-cell non-Hodgkin lymphoma: an Egyptian study.

    PubMed

    Khorshied, Mervat Mamdooh; Gouda, Heba Mahmoud; Khorshid, Ola M Reda

    2014-05-01

    Abstract Genetic and environmental factors are involved in the pathogenesis of non-Hodgkin lymphoma (NHL). The present study aimed to investigate the association between cytotoxic T-lymphocyte antigen 4 (CTLA-4) genetic polymorphism, hepatitis C virus (HCV) infection and B-cell NHL risk in Egypt. Genotyping of CTLA-4 single nucleotide polymorphisms (SNPs) was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay for 181 adult patients with B-NHL and 200 controls. Our study revealed that CTLA-4 + 49 A/G polymorphism conferred increased risk of B-NHL (odds ratio [OR] = 1.7, 95% confidence interval [CI] = 1.36-2.565). The prevalence of HCV infection in individuals harboring the mutant genotype + 49 A/G and - 318 C/T SNPs was higher in patients with B-NHL and was associated with increased risk of B-NHL (OR = 2.79, 95% CI = 1.24-6.93 for + 49 A/G and OR = 3.9, 95% CI = 1.01-15.98 for - 318 C/T). In conclusion, some SNPs of CTLA-4 are genetic risk factors for B-NHL. Moreover, this study identified an association of CTLA-4 + 49 A/G and - 318 C/T promoter polymorphisms with HCV infection.

  3. Herpes Simplex Virus Type 1-Specific Cytotoxic T-Lymphocyte Arming Occurs within Lymph Nodes Draining the Site of Cutaneous Infection

    PubMed Central

    Jones, Claerwen M.; Cose, Stephen C.; Coles, Richard M.; Winterhalter, Adam C.; Brooks, Andrew G.; Heath, William R.; Carbone, Francis R.

    2000-01-01

    Various studies have shown that major histocompatibility complex class I-restricted cytotoxic T lymphocytes (CTL) can be isolated from lymph nodes draining sites of cutaneous infection with herpes simplex virus type 1 (HSV-1). Invariably, detection of this cytolytic activity appeared to require some level of in vitro culture of the isolated lymph node cells, usually for 3 days, in the absence of exogenous viral antigen. This in vitro “resting” period was thought to represent the phase during which committed CD8+ T cells become “armed” killers after leaving the lymph nodes and prior to their entry into infected tissue as effector CTL. In this study we reexamined the issue of CTL appearance in the HSV-1 immune response and found that cytolytic activity can be isolated directly from draining lymph nodes, although at levels considerably below those found after in vitro culture. By using T-cell receptor elements that represent effective markers for class I-restricted T cells specific for an immunodominant glycoprotein B (gB) determinant from HSV-1, we show that the increase in cytotoxicity apparent after in vitro culture closely mirrors the expansion of gB-specific CTL during the same period. Taken together, our results suggest that HSV-1-specific CTL priming does not appear to require any level of cytolytic machinery arming outside the lymph node compartment despite the absence of any detectable infection within that site. PMID:10666272

  4. High-avidity cytotoxic T lymphocytes specific for a new PRAME-derived peptide can target leukemic and leukemic-precursor cells.

    PubMed

    Quintarelli, Concetta; Dotti, Gianpietro; Hasan, Sayyeda T; De Angelis, Biagio; Hoyos, Valentina; Errichiello, Santa; Mims, Martha; Luciano, Luigia; Shafer, Jessica; Leen, Ann M; Heslop, Helen E; Rooney, Cliona M; Pane, Fabrizio; Brenner, Malcolm K; Savoldo, Barbara

    2011-03-24

    The cancer testis antigen (CTA) preferentially expressed antigen of melanoma (PRAME) is overexpressed by many hematologic malignancies, but is absent on normal tissues, including hematopoietic progenitor cells, and may therefore be an appropriate candidate for T cell-mediated immunotherapy. Because it is likely that an effective antitumor response will require high-avidity, PRAME-specific cytotoxic T lymphocytes (CTLs), we attempted to generate such CTLs using professional and artificial antigen-presenting cells loaded with a peptide library spanning the entire PRAME protein and consisting of 125 synthetic pentadecapeptides overlapping by 11 amino acids. We successfully generated polyclonal, PRAME-specific CTL lines and elicited high-avidity CTLs, with a high proportion of cells recognizing a previously uninvestigated HLA-A*02-restricted epitope, P435-9mer (NLTHVLYPV). These PRAME-CTLs could be generated both from normal donors and from subjects with PRAME(+) hematologic malignancies. The cytotoxic activity of our PRAME-specific CTLs was directed not only against leukemic blasts, but also against leukemic progenitor cells as assessed by colony-forming-inhibition assays, which have been implicated in leukemia relapse. These PRAME-directed CTLs did not affect normal hematopoietic progenitors, indicating that this approach may be of value for immunotherapy of PRAME(+) hematologic malignancies. PMID:21278353

  5. Development of an Enhanced Phenotypic Screen of Cytotoxic T-Lymphocyte Lytic Granule Exocytosis Suitable for Use with Synthetic Compound and Natural Product Collections.

    PubMed

    Zhao, Ziyan; deMayo, James A; West, Ashley M; Balunas, Marcy J; Zweifach, Adam

    2016-07-01

    We previously developed an assay of cytotoxic T-lymphocyte lytic granule exocytosis based on externalization of LAMP-1/CD107A using nonphysiological stimuli to generate maximal levels of exocytosis. Here, we used polystyrene beads coated with anti-CD3 antibodies to stimulate cells. Light scatter let us distinguish cells that contacted beads from cells that had not, allowing comparison of signaling events and exocytosis from stimulated and unstimulated cells in one sample. Bead stimulation resulted in submaximal exocytosis, making it possible to detect compounds that either augment or inhibit lytic granule exocytosis. Coupled with the assay's ability to distinguish responses in cells that have and have not contacted a stimulatory bead, it is possible to detect three kinds of compounds: inhibitors, stimulators, which cause exocytosis, and augmenters, which enhance receptor-stimulated exocytosis. To validate the assay, we screened a set of synthetic compounds identified using our previous assay and a library of 320 extracts prepared from tunicate-associated bacteria. One of the extracts augmented exocytosis threefold. Activity-guided fractionation and structure elucidation revealed that this compound is the known PKC activator teleocidin A-1. We conclude that our modified assay is suitable for screening synthetic compound plates and natural product collections, and will be useful for identifying immunologically active small molecules. PMID:27048485

  6. Comparison of cytotoxic T lymphocyte responses against pancreatic cancer induced by dendritic cells transfected with total tumor RNA and fusion hybrided with tumor cell

    PubMed Central

    Chen, Jiang; Li, Hong-Yu; Wang, Di; Shao, Xiao-Dong

    2015-01-01

    Pancreatic cancer (PC) is a deadly human malignancy. Dendritic cell (DC)-based immunotherapy with whole tumor antigens demonstrates potential efficiency in cancer treatment. Tumor RNA and tumor fusion hybrid cells are sources of whole tumor antigens for preparing DC tumor vaccines. However, the efficacy of these sources in eliciting immune responses against PC has not yet to be directly compared. In the present study, patient-derived PC cells and DCs were fused (DC–tumor hybrids) and primary cultured PC cell-derived total RNA was electroporated into autologous DCs (DC–tumor RNA). The antitumor immune responses induced by DC–tumor hybrids and DC–tumor RNA were compared directly. The results showed that both RNA and hybrid methodologies could induce tumor-specific cytotoxic T lymphocyte (CTL) responses, but pulsing DCs with total tumor RNA could induce a higher frequency of activated CTLs and T-helper cells than fusing DCs with autologous tumor cells. In addition, DC–tumor RNA triggered stronger autologous tumor cell lysis than DC–tumor hybrids. It could be concluded that DCs pulsed with whole tumor RNA are superior to those fused with tumor cells in priming anti-PC CTL responses. Electroporation with total tumor RNA may be more suitable for DC-based PC vaccination. PMID:25736302

  7. Gag-Positive Reservoir Cells Are Susceptible to HIV-Specific Cytotoxic T Lymphocyte Mediated Clearance In Vitro and Can Be Detected In Vivo

    PubMed Central

    Graf, Erin H.; Pace, Matthew J.; Peterson, Bennett A.; Lynch, Lindsay J.; Chukwulebe, Steve B.; Mexas, Angela M.; Shaheen, Farida; Martin, Jeffrey N.; Deeks, Steven G.; Connors, Mark; Migueles, Stephen A.; O’Doherty, Una

    2013-01-01

    Resting CD4+ T cells infected with HIV persist in the presence of suppressive anti-viral therapy (ART) and are barriers to a cure. One potential curative approach, therapeutic vaccination, is fueled by recognition of the ability of a subset of elite controllers (EC) to control virus without therapy due to robust anti-HIV immune responses. Controllers have low levels of integrated HIV DNA and low levels of replication competent virus, suggesting a small reservoir. As our recent data indicates some reservoir cells can produce HIV proteins (termed GPR cells for Gag-positive reservoir cells), we hypothesized that a fraction of HIV-expressing resting CD4+ T cells could be efficiently targeted and cleared in individuals who control HIV via anti-HIV cytotoxic T lymphocytes (CTL). To test this we examined if superinfected resting CD4+ T cells from EC express HIV Gag without producing infectious virus and the susceptibility of these cells to CTL. We found that resting CD4+ T cells expressed HIV Gag and were cleared by autologous CD8+ T cells from EC. Importantly, we found the extent of CTL clearance in our in vitro assay correlates with in vivo reservoir size and that a population of Gag expressing resting CD4+ T cells exists in vivo in patients well controlled on therapy. PMID:23951263

  8. Combined analysis of serum alpha-fetoprotein and MAGE-A3-specific cytotoxic T lymphocytes in peripheral blood for diagnosis of hepatocellular carcinoma.

    PubMed

    Cui, Zhuqingqing; Yu, Xin; Guo, Limin; Wei, Yuhua; Zheng, Shengmin; Li, Wenxia; Chen, Pengcheng; Zhu, Jiye; Peng, Jirun

    2013-01-01

    We investigated the feasibility of the combined detection of HLA-A2/MAGE-A3 epitope-specific cytotoxic T lymphocytes (CTLs) and serum alpha-fetoprotein (AFP) for specific diagnosis of hepatocellular carcinoma (HCC). We detected the frequency of MAGE-A3 epitopes (p112-120, KVAELVHFL) in spontaneous CTLs in the peripheral blood of HCC patients, liver cirrhosis patients, and healthy subjects with HLA-A2/polypeptide complex (pentamer) detection technology. Eighty-five HCC cases, 38 liver cirrhosis cases, and 50 healthy cases who were HLA-A2-positive were selected from 175 HCC patients, 80 patients with liver cirrhosis, and 105 healthy volunteers, respectively. The frequency of HLA-A2-specific MAGE-A3(+) CTLs in the HCC group was significantly higher than that in the other groups. Combined detection of MAGE-A3(+) CTL frequency and serum AFP value had a higher specificity than either of the two indicators alone. The pentamer technique is helpful in distinguishing benign lesions and malignant lesions in the liver. Combined with serum AFP, it can improve the diagnosis performance for HCC, especially for AFP-negative cancer. PMID:24427779

  9. Combined Analysis of Serum Alpha-Fetoprotein and MAGE-A3-Specific Cytotoxic T Lymphocytes in Peripheral Blood for Diagnosis of Hepatocellular Carcinoma

    PubMed Central

    Cui, Zhuqingqing; Yu, Xin; Guo, Limin; Wei, Yuhua; Zheng, Shengmin; Li, Wenxia; Chen, Pengcheng; Zhu, Jiye; Peng, Jirun

    2013-01-01

    We investigated the feasibility of the combined detection of HLA-A2/MAGE-A3 epitope-specific cytotoxic T lymphocytes (CTLs) and serum alpha-fetoprotein (AFP) for specific diagnosis of hepatocellular carcinoma (HCC). We detected the frequency of MAGE-A3 epitopes (p112–120, KVAELVHFL) in spontaneous CTLs in the peripheral blood of HCC patients, liver cirrhosis patients, and healthy subjects with HLA-A2/polypeptide complex (pentamer) detection technology. Eighty-five HCC cases, 38 liver cirrhosis cases, and 50 healthy cases who were HLA-A2-positive were selected from 175 HCC patients, 80 patients with liver cirrhosis, and 105 healthy volunteers, respectively. The frequency of HLA-A2-specific MAGE-A3+ CTLs in the HCC group was significantly higher than that in the other groups. Combined detection of MAGE-A3+ CTL frequency and serum AFP value had a higher specificity than either of the two indicators alone. The pentamer technique is helpful in distinguishing benign lesions and malignant lesions in the liver. Combined with serum AFP, it can improve the diagnosis performance for HCC, especially for AFP-negative cancer. PMID:24427779

  10. Human HLA class I- and HLA class II-restricted cloned cytotoxic T lymphocytes identify a cluster of epitopes on the measles virus fusion protein.

    PubMed Central

    van Binnendijk, R S; Versteeg-van Oosten, J P; Poelen, M C; Brugghe, H F; Hoogerhout, P; Osterhaus, A D; Uytdehaag, F G

    1993-01-01

    The transmembrane fusion (F) glycoprotein of measles virus is an important target antigen of human HLA class I- and class II-restricted cytotoxic T lymphocytes (CTL). Genetically engineered F proteins and nested sets of synthetic peptides spanning the F protein were used to determine sequences of F recognized by a number of F-specific CTL clones. Combined N- and C-terminal deletions of the respective peptides revealed that human HLA class I and HLA class II-restricted CTL efficiently recognize nonapeptides or decapeptides representing epitopes of F. Three distinct sequences recognized by three different HLA class II (DQw1, DR2, and DR4/w53)-restricted CTL clones appear to cluster between amino acids 379 and 466 of F, thus defining an important T-cell epitope area of F. Within this same region, a nonamer peptide of F was found to be recognized by an HLA-B27-restricted CTL clone, as expected on the basis of the structural homology between this peptide and other known HLA-B27 binding peptides. PMID:7680390

  11. Oral immunization with recombinant Mycobacterium bovis BCG simian immunodeficiency virus nef induces local and systemic cytotoxic T-lymphocyte responses in mice.

    PubMed Central

    Lagranderie, M; Balazuc, A M; Gicquel, B; Gheorghiu, M

    1997-01-01

    Recombinant live Mycobacterium bovis BCG vectors (rBCG) induce strong cellular and humoral immune responses against various antigens after either systemic or oral immunization of mice. Cytotoxic T-lymphocyte (CTL) responses may contribute to the control of human immunodeficiency virus (HIV) or simian immunodeficiency virus (SIV) infections whose portal of entry is the gastrointestinal or genital mucosa. In this study, we immunized BALB/c mice with a recombinant BCG SIV nef and observed its behavior in oropharyngeal and target organ lymphoid tissues. The cellular immune responses, particularly the intestinal intraepithelial and systemic CTL responses, were investigated. The results showed that rBCG SIV nef translocated the oropharyngeal mucosa and intestinal epithelium. It diffused to and persisted in target lymphoid organs. Specific SIV Nef peptide proliferative responses and cytokine production were observed. Strong systemic and mucosal CTL responses were induced. In particular, we demonstrated direct specific anti-Nef CTL in intestinal intraepithelial CD8beta+ T cells. These findings provide evidence that orally administered rBCG SIV nef may contribute to local defenses against viral invasion. Therefore, rBCG SIV nef could be a candidate vaccine to protect against SIV infection and may be used to develop an oral rBCG HIV nef vaccine. PMID:9032366

  12. An HLA-C-restricted CD8+ cytotoxic T-lymphocyte clone recognizes a highly conserved epitope on human immunodeficiency virus type 1 gag.

    PubMed Central

    Littaua, R A; Oldstone, M B; Takeda, A; Debouck, C; Wong, J T; Tuazon, C U; Moss, B; Kievits, F; Ennis, F A

    1991-01-01

    A unique epitope on the gag protein of human immunodeficiency virus type 1 (HIV-1), located at amino acid 145 to 150, has been mapped by using a CD8+ cytotoxic T-lymphocyte (CTL) clone. This epitope is highly conserved among 18 HIV-1 strains. The HIV-1 gag-specific human leukocyte antigen (HLA) class I-restricted CD8+ CTL clone was generated from fresh peripheral blood mononuclear cells of an HIV-seropositive donor by stimulation with gamma-irradiated allogeneic peripheral blood mononuclear cells in the presence of an anti-CD3 monoclonal antibody and recombinant interleukin-2. This gag-specific CTL clone killed autologous target cells infected with a recombinant vaccinia virus containing the gag gene of HIV-1 and target cells pulsed with an authentic p24gag construct expressed in Escherichia coli. Fine specificity was determined by using a panel of overlapping 30-amino-acid-long synthetic peptides and subsequently using smaller peptides to precisely map the CTL domain on p24. The epitope is on a highly conserved region, and it overlaps with a major B-cell epitope of gag. This CD8+ T-cell epitope is restricted by HLA-Cw3, which has not been previously identified as a restricting element for human CTL responses. PMID:1712857

  13. Selection of genetic variants of lymphocytic choriomeningitis virus in spleens of persistently infected mice. Role in suppression of cytotoxic T lymphocyte response and viral persistence

    PubMed Central

    1984-01-01

    We studied the mechanism of lymphocytic choriomeningitis virus (LCMV) persistence and the suppression of cytotoxic T lymphocyte (CTL) responses in BALB/c WEHI mice infected at birth with LCMV Armstrong strain. Using adoptive transfer experiments we found that spleen cells from persistently infected (carrier) mice actively suppressed the expected LCMV-specific CTL response of spleen cells from normal adult mice. The suppression was specific for the CTL response and LCMV - specific antibody responses were not affected. Associated with the specific CTL suppression was the establishment of persistent LCMV infection. The transfer of spleen or lymph node cells containing LCMV - specific CTL resulted in virus clearance and prevented establishment of the carrier state. The suppression of LCMV -specific CTL responses by carrier spleen cells is not mediated by a suppressor cell, but is due to the presence of genetic variants of LCMV in spleens of carrier mice. Such virus variants selectively suppress LCMV-specific CTL responses and cause persistent infections in immunocompetent mice. In striking contrast, wild-type LCMV Armstrong, from which these variants were generated, induces a potent CTL response in immunocompetent mice and the LCMV infection is rapidly cleared. Our results show that LCMV variants that emerge during infection in vivo play a crucial role in the suppression of virus-specific CTL responses and in the maintenance of virus persistence. PMID:6332167

  14. Human papillomavirus type 16 E6/E7-specific cytotoxic T lymphocytes for adoptive immunotherapy of HPV-associated malignancies.

    PubMed

    Ramos, Carlos A; Narala, Neeharika; Vyas, Gayatri M; Leen, Ann M; Gerdemann, Ulrike; Sturgis, Erich M; Anderson, Matthew L; Savoldo, Barbara; Heslop, Helen E; Brenner, Malcolm K; Rooney, Cliona M

    2013-01-01

    Vaccines prevent human papillomavirus (HPV)-associated cancer but, although these tumors express foreign, viral antigens (E6 and E7 proteins), they have little benefit in established malignancies, likely due to negative environmental cues that block tumor recognition and induce T-cell anergy in vivo. We postulated that we could identify mechanisms by which ex vivo stimulation of T cells could reactivate and expand tumor-directed T-cell lines from HPV cancer patients for subsequent adoptive immunotherapy. A total of 68 patients with HPV-associated cancers were studied. Peripheral blood T cells were stimulated with monocyte-derived dendritic cells loaded with pepmixes [peptide libraries of 15-mers overlapping by 11 amino acids (aa)] spanning E6/E7, in the presence or absence of specific accessory cytokines. The resulting T-cell lines were further expanded with pepmix-loaded activated B-cell blasts. Interferon-γ release and cytotoxic responses to E6/E7 were assessed. We successfully reactivated and expanded (>1200-fold) E6-specific/E7-specific T cells from 8/16 cervical and 33/52 oropharyngeal cancer patients. The presence of the cytokines interleukin (IL)-6, IL-7, IL-12, and IL-15 is critical for this process. These T-cell lines possess the desirable characteristics of polyclonality, multiple T-cell subset representation (including the memory compartment) and a TH1 bias, and may eliminate E6/E7 targets. In conclusion, we have shown it is possible to robustly generate HPV16 E6/E7-directed T-cell lines from patients with HPV16-associated cancers. Because our technique is scalable and good-manufacturing procedures-compliant, these lines could be used for adoptive cellular immunotherapy of patients with HPV16 cancers.

  15. Identification of an H2-Kb or H2-Db restricted and glypican-3-derived cytotoxic T-lymphocyte epitope peptide

    PubMed Central

    IWAMA, TATSUAKI; HORIE, KAZUTAKA; YOSHIKAWA, TOSHIAKI; NOBUOKA, DAISUKE; SHIMOMURA, MANAMI; SAWADA, YU; NAKATSURA, TETSUYA

    2013-01-01

    Glypican-3 (GPC3) is overexpressed in human hepatocellular carcinoma (HCC) but not expressed in normal tissues except for placenta and fetal liver and therefore is an ideal target for cancer immunotherapy. In this study, we identified an H2-Kb or H2-Db restricted and murine GPC3 (mGPC3)-derived cytotoxic T-lymphocyte (CTL) epitope peptide in C57BL/6 (B6) mice, which can be used in the design of preclinical studies of various therapies with GPC3-target immunotherapy in vivo. First, 11 types of 9- to 10-mer peptides predicted to bind with H2-Kb or H2-Db were selected from the mGPC3 amino acid sequence based on the binding score as calculated by the BIMAS software. We evaluated the peptide-binding affinity and confirmed that all peptides were able to bind to H2-Kb or H2-Db by in vitro cellular binding assay. Subsequently, a mixed peptide vaccine and single peptide vaccine were given to B6 mice to evaluate immunogenic potential of the 11 selected peptides. Using the splenocytes from peptide-vaccinated mice, interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) assays showed that mGPC3-1127–136 (AMFKNNYPSL) peptide was the most efficient for inducing CTLs among the 11 peptides. Next, we demonstrated that the mGPC3-1 peptide-specific CTL line could recognize mGPC3-expressing cancer cells, suggesting that mGPC3-1 peptide was an endogenously presented peptide. In conclusion, we identified mGPC3-1 as an H2-Kb or H2-Db restricted, mGPC3-derived CTL epitope peptide. PMID:23354275

  16. Association of Cytotoxic T-Lymphocyte-Associated Protein 4 (CTLA4) Gene Polymorphisms with Autoimmune Thyroid Disease in Children and Adults: Case-Control Study

    PubMed Central

    Lo, Fu-Sung; Wang, Chao-Hung; Huang, Chi-Yu; Lin, Chiung-Ling; Lin, Wen-Shan; Chang, Tzu-Yang; Yang, Horng-Woei; Chen, Wei-Fang; Lien, Ya-Ping; Cheng, Bi-Wen; Lin, Chao-Hsu; Chen, Chia-Ching; Wu, Yi-Lei; Hung, Chen-Mei; Li, Hsin-Jung; Chan, Chon-In; Lee, Yann-Jinn

    2016-01-01

    Autoimmune thyroid disease (AITD), including Graves disease (GD) and Hashimoto disease (HD), is an organ-specific autoimmune disease with a strong genetic component. Although the cytotoxic T-lymphocyte-associated protein 4 (CTLA4) polymorphism has been reported to be associated with AITD in adults, few studies have focused on children. The aim of our study was to investigate whether the CTLA4 polymorphisms, including -318C/T (rs5742909), +49A/G (rs231775), and CT60 (rs3087243), were associated with GD and HD in Han Chinese adults and children. We studied 289 adult GD, 265 pediatric GD, 229 pediatric HD patients, and 1058 healthy controls and then compared genotype, allele, carrier, and haplotype frequencies between patients and controls. We found that CTLA4 SNPs +49A/G and CT60 were associated with GD in adults and children. Allele G of +49A/G was significantly associated with GD in adults (odds ratio [OR], 1.50; 95% confidence interval [CI], 1.21–1.84; corrected P value [Pc] < 0.001) and children (OR, 1.42; 95% CI, 1.15–1.77; Pc = 0.002). Allele G of CT60 also significantly increased risk of GD in adults (OR, 1.63; 95% CI, 1.27–2.09; Pc < 0.001) and GD in children (OR, 1.58; 95% CI, 1.22–2.04; Pc < 0.001). Significant linkage disequilibrium was found between +49A/G and CT60 in GD and control subjects (D’ = 0.92). Our results showed that CTLA4 was associated with both GD and HD and played an equivalent role in both adult and pediatric GD in Han Chinese population. PMID:27111218

  17. Recognition of a highly conserved region of human immunodeficiency virus type 1 gp120 by an HLA-Cw4-restricted cytotoxic T-lymphocyte clone.

    PubMed Central

    Johnson, R P; Trocha, A; Buchanan, T M; Walker, B D

    1993-01-01

    Human immunodeficiency virus type 1 (HIV-1) isolates exhibit extensive sequence variation, particularly in the gp120 subunit of the envelope glycoprotein, and the degree of this variation has raised questions as to whether conserved regions of the HIV-1 envelope can be recognized by the host immune response. A CD8+ cytotoxic T-lymphocyte (CTL) clone specific for the HIV-1 envelope was derived by culturing peripheral blood mononuclear cells from an HIV-1 seropositive subject in the presence of a CD3-specific monoclonal antibody, interleukin-2, and irradiated allogeneic peripheral blood mononuclear cells. Lysis of target cells was restricted by an HLA-C molecule, Cw4, which has not been previously shown to present viral antigen to CTL. Mapping of the specificity of this CTL clone by using synthetic HIV-1 peptides localized the epitope to an 8-amino-acid region of gp120 (amino acids 376 to 383) which is conserved among approximately 90% of sequenced viral isolates. Examination of the recognition of variant peptides by this CTL clone demonstrated that a single, nonconservative amino acid substitution within the 8-amino-acid minimal epitope could abrogate lysis of targets incubated with the variant peptide. The identification of a CTL epitope in a highly conserved region of gp120 documents the ability of cellular immune responses of infected persons to respond to relatively invariant portions of this highly variable envelope glycoprotein. However, the ability of even a single-amino-acid change in gp120 to abolish lysis by CTL supports the hypothesis that sequence variation in HIV-1 may serve as a mechanism of immune escape. In addition, the identification of an HLA-C molecule presenting viral antigen to CTL supports a functional role for these molecules. PMID:7677956

  18. Therapeutic effect of interleukin 12 on mouse haemangiosarcomas is not associated with an increased anti-tumour cytotoxic T-lymphocyte activity.

    PubMed Central

    Vizler, C.; Rosato, A.; Calderazzo, F.; Quintieri, L.; Fruscella, P.; Wainstok de Calmanovici, R.; Mantovani, A.; Vecchi, A.; Zanovello, P.; Collavo, D.

    1998-01-01

    In syngeneic mice, the H5V polyoma middle-T oncogene-transformed endothelioma cell line induces Kaposi's sarcoma-like cavernous haemangiomas that regress transiently, probably because of an anti-tumour immune response, but eventually grow progressively and kill the host. To evaluate the generation of tumour-specific cytotoxic T lymphocytes (CTLs), spleen cells of tumour-bearing mice were restimulated with irradiated H5V cells in mixed leucocyte-tumour cell cultures. Tumour-specific CTLs were demonstrable only when low numbers of H5V stimulator cells were used (<1 H5V cell per 50 splenocytes). We found that H5V cells secrete immunosuppressive mediators because CTL generation was blocked when H5V cells culture supernatants were added to allogeneic mixed leucocyte cultures. As numerous tumour-derived immunosuppressive mediators may interfere with interleukin 12 (IL-12) production, we tested whether IL-12 treatment of the tumour-bearing mice would augment their immune response and thus suppress tumour growth. Indeed, IL-12 inhibited tumour growth and prevented mortality, but did not increase anti-H5V CTL generation either in vitro or in vivo. Moreover, the anti-tumour activity in IL-12-treated mice was abrogated by anti-interferon (IFN)-gamma monoclonal antibody (MAb) co-administration. These results strongly suggest that the anti-tumour effect of IL-12 is principally mediated by IFN-gamma release that in turn blocks H5V cell proliferation and induces the release of factors that suppress angiogenesis. PMID:9484826

  19. HLA-A2-Restricted Cytotoxic T Lymphocyte Epitopes from Human Heparanase as Novel Targets for Broad-Spectrum Tumor Immunotherapy1

    PubMed Central

    Chen, Ting; Tang, Xu-Dong; Wan, Yin; Chen, Ling; Yu, Song-Tao; Xiong, Zhen; Fang, Dian-Chun; Liang, Guang-Ping

    2008-01-01

    Peptide vaccination for cancer immunotherapy requires identification of peptide epitopes derived from antigenic proteins associated with tumors. Heparanase (Hpa) is broadly expressed in various advanced tumors and seems to be an attractive new tumor-associated antigen. The present study was designed to predict and identify HLA-A2-restricted cytotoxic T lymphocyte (CTL) epitopes in the protein of human Hpa. For this purpose, HLA-A2-restricted CTL epitopes were identified using the following four-step procedure: 1) a computer-based epitope prediction from the amino acid sequence of human Hpa, 2) a peptide-binding assay to determine the affinity of the predicted protein with the HLA-A2 molecule, 3) stimulation of the primary T-cell response against the predicted peptides in vitro, and 4) testing of the induced CTLs toward different kinds of carcinoma cells expressing Hpa antigens and/or HLA-A2. The results demonstrated that, of the tested peptides, effectors induced by peptides of human Hpa containing residues 525–533 (PAFSYSFFV, Hpa525), 277–285 (KMLKSFLKA, Hpa277), and 405–413 (WLSLLFKKL, Hpa405) could effectively lyse various tumor cell lines that were Hpa-positive and HLA-A2-matched. We also found that these peptide-specific CTLs could not lyse autologous lymphocytes with low Hpa activity. Further study revealed that Hpa525, Hpa277, and Hpa405 peptides increased the frequency of IFN-γ-producing T cells compared to a negative peptide. Our results suggest that Hpa525, Hpa277, and Hpa405 peptides are new HLA-A2-restricted CTL epitopes capable of inducing Hpa-specific CTLs in vitro. Because Hpa is expressed in most advanced malignant tumors, Hpa525, Hpa277, and Hpa405 peptide-based vaccines may be useful for the immunotherapy for patients with advanced tumors. PMID:18714399

  20. Japanese encephalitis virus infection of mouse cell lines: ability to prime mice for generation of virus specific cytotoxic T lymphocytes and differences in CTL recognisable viral determinants.

    PubMed

    Murali-Krishna, K; Ravi, V; Manjunath, R

    1995-01-01

    Ten different mouse cell lines were examined for Japanese encephalitis virus (JEV) infection in vitro and then tested for their ability to generate virus specific cytotoxic T lymphocytes (CTL). Among all cell lines examined, Neuro 2a (a neuroblastoma) was readily infected with JEV as examined by immunofluorescence and viral replication. Among other cells, P388D1, RAW 264.7 (Macrophage origin), Sp2/0 (B-cell Hybridoma), YAC-1 (T-cell lymphoma), and L929 (Fibroblast) were semipermissive to JEV infection. The cytopathic effects caused by progressive JEV infection varied from cell line to cell line. In the case of YAC-1 cells long-term viral antigen expression was observed without significant alterations in cell viability. Intermediate degrees of cytopathicity are seen in RAW 264.7 and L929 cells while infection of PS, Neuro 2a, P388D1 and Sp2/0 caused major viability losses. All infected cell lines were able to prime adult BALB/c (H-2d) mice for the generation of secondary JEV specific CTL. In contrast to YAC-1, the permissive neuroblastoma cell line Neuro 2a (H-2KkDd) was found to be least efficient in its ability to stimulate anti-viral CTL generation. Cold target competition studies demonstrated that both Neuro 2a and YAC-1 (H-2KkDd) cells expressed similar viral determinants that are recognised by CTL, suggesting that the reason for the lower ability of Neuro 2a to stimulate anti-viral CTL was not due to lack of viral CTL determinants. These findings demonstrate that a variety of mouse cell lines can be infected with Japanese encephalitis virus, and that these infected cells could be utilised to generate virus specific CTL in BALB/c mice.

  1. Virus-specific HLA-restricted lysis of herpes simplex virus-infected human monocytes and macrophages mediated by cytotoxic T lymphocytes

    SciTech Connect

    Torpey, D.J. III

    1987-01-01

    Freshly-isolated peripheral blood human monocytes and 5 day in vitro cultured macrophages were infected with herpes simplex virus type 1 (HSV-1), labeled with /sup 51/Cr, and used as target cells in a 12-14 hour cell-mediated cytotoxicity assay. Mononuclear leukocytes (MNL) from HSV-1 non-immune individuals, whether unstimulated or stimulated with HSV-1 antigen, did not mediate significant lysis of either target cell. HSV-immune MNL, both freshly-isolated and cultured for 5 days without antigen, demonstrated only low levels of natural killer (NK) cell-mediate lysis. MNL from HSV-immune individuals incubated for 5 days in vitro with HSV-1 antigen mediated significant virus-specific lysis of both target cells. Mean virus-specific lysis of autologous monocytes was 8.5(/+-/2.0)% compared to a three-fold greater virus-specific lysis of autologous macrophages. Greater than 70% of this lytic activity was mediated by Leu-11-negative, T3-positive cytotoxic T lymphocytes (CTL). Allogeneic target cells lacking a common HLA determinant were not significantly lysed while T8-positive CTL mediated infrequent lysis of target cells sharing a common HLA-A and/or HLA-B determinant. T4-positive lymphocytes were demonstrated to be the predominant cell mediating lysis of autologous target cells and allogeneic target cells sharing both HLA-A and/or HLA-B plus HLA-DR determinants with the CTL; the T4-positive cell was the sole CTL mediator of lysis of allogeneic target cells having a common HLA-DR determinant.

  2. Human Cytotoxic T Lymphocytes Directed to Seasonal Influenza A Viruses Cross-React with the Newly Emerging H7N9 Virus

    PubMed Central

    van de Sandt, Carolien E.; Kreijtz, Joost H. C. M.; de Mutsert, Gerrie; Geelhoed-Mieras, Martina M.; Hillaire, Marine L. B.; Vogelzang-van Trierum, Stella E.; Osterhaus, Albert D. M. E.; Fouchier, Ron A. M.

    2014-01-01

    In February 2013, zoonotic transmission of a novel influenza A virus of the H7N9 subtype was reported in China. Although at present no sustained human-to-human transmission has been reported, a pandemic outbreak of this H7N9 virus is feared. Since neutralizing antibodies to the hemagglutinin (HA) globular head domain of the virus are virtually absent in the human population, there is interest in identifying other correlates of protection, such as cross-reactive CD8+ T cells (cytotoxic T lymphocytes [CTLs]) elicited during seasonal influenza A virus infections. These virus-specific CD8+ T cells are known to recognize conserved internal proteins of influenza A viruses predominantly, but it is unknown to what extent they cross-react with the newly emerging H7N9 virus. Here, we assessed the cross-reactivity of seasonal H3N2 and H1N1 and pandemic H1N1 influenza A virus-specific polyclonal CD8+ T cells, obtained from HLA-typed study subjects, with the novel H7N9 virus. The cross-reactivity of CD8+ T cells to H7N9 variants of known influenza A virus epitopes and H7N9 virus-infected cells was determined by their gamma interferon (IFN-γ) response and lytic activity. It was concluded that, apart from recognition of individual H7N9 variant epitopes, CD8+ T cells to seasonal influenza viruses display considerable cross-reactivity with the novel H7N9 virus. The presence of these cross-reactive CD8+ T cells may afford some protection against infection with the new virus. PMID:24257602

  3. Characterization of CD8+ cytotoxic T-lymphocyte responses after genetic immunization with retrovirus vectors expressing different forms of the hepatitis B virus core and e antigens.

    PubMed Central

    Townsend, K; Sällberg, M; O'Dea, J; Banks, T; Driver, D; Sauter, S; Chang, S M; Jolly, D J; Mento, S J; Milich, D R; Lee, W T

    1997-01-01

    Cytotoxic T-lymphocyte (CTL) activity appears to play an important role in resolving hepatitis B virus (HBV) infection, and the ability to induce such responses remains an important goal for developing effective immunotherapeutics. A panel of recombinant retrovirus vectors expressing different forms of the HBV core antigen (HBcAg) or e antigen (eAg) were found to induce antigen-specific major histocompatibility complex-restricted CTL responses in both mice and macaques. In addition, a novel retrovirus vector expressing an HBcAg-neomycin phosphotransferase II (HBc-Neo) fusion protein [LHBc-NEO(6A3)], which allows the measurement of the anti-Neo antibody response as a means of directly tracking biological activity of the vector, was generated. Doses greater than 10(7) CFU were necessary to induce CTL responses in H-2(k) mice. Intramuscular injections with 10(8) CFU of the LHBc-NEO(6A3) retrovirus vector into rhesus monkeys induced HBc/eAg-specific antibody production and CD8+ CTLs. The CTL response from one of the two responder rhesus monkeys was directed against a 9-residue peptide, GELMTLATW, at positions 63 to 71 of the HBc/eAg sequence. The CTL response is long lived, being detectable as late as 16 weeks after immunization, and can be boosted upon reimmunization. The potent ability of recombinant retrovirus vectors to induce HBcAg- and eAg-specific CTL responses may prove beneficial as a therapeutic treatment for chronic hepatitis B infection. PMID:9094605

  4. Target cell death triggered by cytotoxic T lymphocytes: a target cell mutant distinguishes passive pore formation and active cell suicide mechanisms.

    PubMed Central

    Ucker, D S; Wilson, J D; Hebshi, L D

    1994-01-01

    The role of the target cell in its own death mediated by cytotoxic T lymphocytes (CTL) has been controversial. The ability of the pore-forming granule components of CTL to induce target cell death directly has been taken to suggest an essentially passive role for the target. This view of CTL-mediated killing ascribes to the target the single role of providing an antigenic stimulus to the CTL; this signal results in the vectoral degranulation and secretion of pore-forming elements onto the target. On the other hand, by a number of criteria, target cell death triggered by CTL appears fundamentally different from death resulting from membrane damage and osmotic lysis. CTL-triggered target cell death involves primary internal lesions of the target cell that reflect a physiological cell death process. Orderly nuclear disintegration, including lamin phosphorylation and solubilization, chromatin condensation, and genome digestion, are among the earliest events, preceding the loss of plasma membrane integrity. We have tested directly the involvement of the target cell in its own death by examining whether we could isolate mutants of target cells that have retained the ability to be recognized by and provide an antigenic stimulus to CTL while having lost the capacity to respond by dying. Here, we describe one such mutant, BW87. We have used this CTL-resistant mutant to analyze the mechanisms of CTL-triggered target cell death under a variety of conditions. The identification of a mutable target cell element essential for the cell death response to CTL provides genetic evidence that target cell death reflects an active cell suicide process similar to other physiological cell deaths. PMID:8264610

  5. Identification of HLA-A*0201-Restricted Cytotoxic T Lymphocyte Epitopes Derived from HLA-DOβ as a Novel Target for Multiple Myeloma

    PubMed Central

    Kang, Yoon Joong; Zeng, Wanyong; Song, Weihua; Reinhold, Bruce; Choi, Jaewon; Brusic, Vladimir; Yamashita, Takuto; Munshi, Aditya; Li, Cheng; Minvielle, Stephane; Anderson, Kenneth C.; Munshi, Nikhil; Reinherz, Ellis L.; Sasada, Tetsuro

    2014-01-01

    Summary Despite the recent development of effective therapeutic agents against multiple myeloma (MM), new therapeutic approaches, including immunotherapies, remain to be developed. Here we identified novel human leucocyte antigen (HLA)-A*0201 (HLAA2)-restricted cytotoxic T lymphocyte (CTL) epitopes from a B cell specific molecule HLA-DOβ (DOB) as a potential target for MM. By DNA microarray analysis, the HLADOB expression in MM cells was significantly higher than that in normal plasma cells. Twenty-five peptides were predicted to bind to HLA-A2 from the amino acid sequence of HLA-DOB. When screened for the immunogenicity in HLA-A2-transgenic mice immunized with HLA-DOB cDNA, 4 peptides were substantially immunogenic. By mass spectrometry analysis of peptides eluted from HLA-A2-immunoprecipitates of MM cell lines, only two epitopes, HLA-DOB232-240 (FLLGLIFLL) and HLA-DOB185-193 (VMLEMTPEL), were confirmed for their physical presence on cell surface. When healthy donor blood was repeatedly stimulated in vitro with these two peptides and assessed by antigen-specific γ-interferon secretion, HLA-DOB232-240 was more immunogenic than HLA-DOB185-193. Additionally, the HLA-DOB232-240-specific CTLs, but not the HLA-DOB185-193-specific CTLs, displayed an major histocompatibility complex class I-restricted reactivity against MM cell lines expressing both HLA-A2 and HLA-DOB. Taken together, based on the physical presence on tumour cell surface and high immunogenicity, HLA-DOB232-240 might be useful for developing a novel immunotherapy against MM. PMID:24032635

  6. Improved cytotoxic T-lymphocyte immune responses to a tumor antigen by vaccines co-expressing the SLAM-associated adaptor EAT-2.

    PubMed

    Aldhamen, Y A; Seregin, S S; Kousa, Y A; Rastall, D P W; Appledorn, D M; Godbehere, S; Schutte, B C; Amalfitano, A

    2013-10-01

    The signaling lymphocytic activation molecule-associated adaptor Ewing's sarcoma's-activated transcript 2 (EAT-2) is primarily expressed in dendritic cells, macrophages and natural killer cells. Including EAT-2 in a vaccination regimen enhanced innate and adaptive immune responses toward pathogen-derived antigens, even in the face of pre-existing vaccine immunity. Herein, we investigate whether co-vaccinations with two recombinant Ad5 (rAd5) vectors, one expressing the carcinoembryonic antigen (CEA) and one expressing EAT-2, can induce more potent CEA-specific cytotoxic T lymphocyte (CTL) and antitumor activity in the therapeutic CEA-expressing MC-38 tumor model. Our results suggest that inclusion of EAT-2 significantly alters the kinetics of Th1-biasing proinflammatory cytokine and chemokine responses, and enhances anti-CEA-specific CTL responses. As a result, rAd5-EAT2-augmented rAd5-CEA vaccinations are more efficient in eliminating CEA-expressing target cells as measured by an in vivo CTL assay. Administration of rAd5-EAT2 vaccines also reduced the rate of growth of MC-38 tumor growth in vivo. Also, an increase in MC-38 tumor cell apoptosis (as measured by hematoxylin and eosin staining, active caspase-3 and granzyme B levels within the tumors) was observed. These data provide evidence that more efficient, CEA-specific effector T cells are generated by rAd5 vaccines expressing CEA, when augmented by rAd5 vaccines expressing EAT-2, and this regimen may be a promising approach for cancer immunotherapy in general.

  7. ENV-specific cytotoxic T lymphocyte responses in HIV seronegative health care workers occupationally exposed to HIV-contaminated body fluids.

    PubMed Central

    Pinto, L A; Sullivan, J; Berzofsky, J A; Clerici, M; Kessler, H A; Landay, A L; Shearer, G M

    1995-01-01

    Identification of the components of protective immunity are crucial for the development of effective prophylactic and therapeutic vaccine strategies. Analysis of HIV-specific responses in exposed but uninfected individuals might thus provide a unique resource to elucidate the components and correlates of protective immunity to HIV. In the present study we analyzed HIV-specific cytotoxic and helper T lymphocyte responses in health care workers (HCW) exposed to body fluids from HIV-positive individuals. HCW exposed to blood from HIV-negative individuals as well as healthy donors served as controls. Cytotoxic T lymphocyte (CTL) responses to HIV envelope (env) peptides were detected in 7/20 (35%) HCW exposed to HIV-positive blood and in none of the 20 health care workers exposed to uninfected blood or the seven healthy blood donors studied. HIV-specific CTL responses were detected only after in vitro stimulation, and were MHC class I restricted. No MHC class I restriction elements were uniformly identified among the different responders. 21/28 (75%) HCW exposed to contaminated blood responded to env as measured by IL-2 production to the peptides, in contrast to only 9/38 (24%) HCW exposed to HIV seronegative blood and 3/35 (9%) healthy blood donors. All the HIV exposed individuals were seronegative on repeated ELISA tests, and no evidence of infection was obtained by PCR analysis. These findings indicate that a single exposure to HIV can induce CTL immunity to HIV antigens, in the absence of other evidence of infection. Images PMID:7635981

  8. Early detection of cytomegalovirus-specific cytotoxic T lymphocytes against cytomegalovirus antigenemia in human leukocyte antigen haploidentical hematopoietic stem cell transplantation.

    PubMed

    Kato, Ruri; Tamaki, Hiroya; Ikegame, Kazuhiro; Yoshihara, Satoshi; Kaida, Katsuji; Taniguchi, Kyoko; Inoue, Takayuki; Ishii, Shinichi; Nakata, Jun; Fujioka, Tatsuya; Eguchi, Ryoji; Soma, Toshihiro; Okada, Masaya; Ogawa, Hiroyasu

    2015-10-01

    Human leukocyte antigen (HLA)-haploidentical stem cell transplantation (haplo-SCT) is associated with a high incidence of cytomegalovirus (CMV) infection, probably originating from the delayed reconstitution of CMV-specific T cell immunity. There have been few reports on the presence of CMV-specific cytotoxic T lymphocytes (CMV-CTLs) after haplo-SCT. We have studied CMV-specific immune reconstitution by measuring the absolute number of CMV-CTLs using a flow cytometry method with HLA-A2-restricted NLVPMVATV peptide dextramers. We examined the association between reconstitution patterns of CMV-CTLs and the duration of CMV antigenemia in 15 patients who underwent first allogeneic SCT from HLA-haploidentical-related donors with HLA-A2. In seven and eight patients, CMV antigenemia consecutively resolved for more than 4 weeks (the CMV antigenemia 'resolved' group) and intermittently persisted (the CMV antigenemia 'persistent' group) during a 100-day observation period, respectively. The group of the seven patients, in whom levels of CMV antigenemia were reduced to zero, had a significantly lower maximum level of CMV antigenemia than the CMV antigenemia persistent group. In contrast, the CMV antigenemia persistent group had a significantly higher maximum level of CMV-CTLs, but the levels took longer to peak. Despite no difference in general lymphocyte recovery between the two groups, the CMV antigenemia resolved group had significantly higher median CMV-CTL counts than the CMV antigenemia persistent group at 6 weeks after onset of CMV infection. Flow cytometry analysis of CMV-CTLs is a convenient method of monitoring reconstitution of CMV-specific lymphocyte immunity following haplo-SCT.

  9. Influence of the route of infection on development of T-cell receptor beta-chain repertoires of reovirus-specific cytotoxic T lymphocytes.

    PubMed

    Fulton, Jonathan R; Smith, Jeremy; Cunningham, Cynthia; Cuff, Christopher F

    2004-02-01

    It is well established that the route of infection affects the nature of the adaptive immune response. However, little is known about the effects of the route of exposure on development of cytotoxic T-lymphocyte (CTL) responses. Alternative antigen-presenting cell populations, tissue-restricted expression of class I major histocompatibility complex-encoded molecules, and unique T-cell receptor (TCR)-bearing cells in mucosal tissues could influence the selection and expansion of responder T cells. This study addresses the question of whether the route of virus infection affects the selection and expansion of subpopulations of virus-specific CTLs. Mice were infected orally or in the hind footpads with reovirus, and the repertoires of TCR beta-chains expressed on virus-specific CD8(+) T cells in Peyer's patches or lymph nodes and spleens were examined. CD8(+) cells expressing the variable gene segment of the TCR beta-chain 6 (Vbeta6) expanded in the spleens of mice infected by either route and in CTL lines established from the spleens and draining lymphoid tissues. Adoptively transferred Vbeta6(+) CD8(+) T cells from orally or parenterally infected donors expanded in reovirus-infected severe combined immunodeficient recipient mice and mediated cytotoxicity ex vivo. Furthermore, recovered Vbeta6(+) cells were enriched for clones utilizing uniform complementarity-determining region 3 (CDR3) lengths. However, sequencing of CDR3beta regions from Vbeta6(+) CD8(+) cells indicated that Jbeta gene segment usage is significantly more restricted in CTLs from orally infected mice, suggesting that the route of infection affects selection and/or subsequent expansion of virus-specific CTLs. PMID:14722312

  10. Possible involvement of the OKT4 molecule in T cell recognition of class II HLA antigens. Evidence from studies of cytotoxic T lymphocytes specific for SB antigens.

    PubMed

    Biddison, W E; Rao, P E; Talle, M A; Goldstein, G; Shaw, S

    1982-10-01

    A recently described HLA gene, SB, which maps between GLO and HLA-DR, codes for Ia-like molecules that are similar to but distinct from HLA-DR molecules. Cytotoxic T lymphocytes (CTL) specific for SB1, SB2, SB3, and SB4 were compared with HLA-A2-specific CTL with respect to their surface expression of the T cell differentiation antigens OKT3, OKT4, and OKT8. All CTL activity was eliminated by treatment with OKT3 and C'. The SB-specific cytotoxicity was eliminated by OKT4 plus C' but not by OKT8 plus C'. In contrast, HLA-A2-specific killing was completely susceptible to treatment with OKT8 plus C' but not with OKT4 plus C'. Cytotoxicity was analyzed in the presence of OKT8 and a series of monoclonal antibodies (OKT4A, 4B, 4C, and 4D) that react with distinct epitopes on the OKT4 molecule. SB1-, SB3-, and SB4-specific CTL were partially inhibited by OKT4A and 4B (45-75%), whereas HLA-A2-specific CTL were partially inhibited by OKT8 (48-63%) but not by OKT4. SB2-specific CTL were not inhibited (less than 26%) by OKT8 or by any of the OKT4-related antibodies. These results suggest that the OKT4 marker may be expressed on most T cells that recognize allogeneic Ia or self Ia plus foreign antigens; OKT4+ cells do not appear to be functionally homogeneous in that they can act both as helper/inducer and cytotoxic cells. Models are proposed for the functional involvement of the OKT4 molecule in T cell-Ia antigen interactions. PMID:6984061

  11. A novel beta 4, alpha 6 integrin-associated epithelial cell antigen involved in natural killer cell and antigen-specific cytotoxic T lymphocyte cytotoxicity

    PubMed Central

    1991-01-01

    Efficient immune responses require interactions between cell adhesion molecules on lymphocytes and counter-receptors on antigen presenting cells or target cells. While target-specific receptors or ligands have not been identified for natural killer (NK) cells, cell adhesion molecules have been implicated in the interaction between NK cell effectors and tumor cell targets. Herein, we describe monoclonal antibodies (mAbs) against a carcinoma cell line that efficiently block the cytolytic activity of interleukin 2-activated NK cell lines and clones. L280 mAb reacts with secretory epithelial cells in normal human tissues, but does not react with hematopoietic cells or other tissue types. Biochemical analysis revealed that L280 mAb immunoprecipitates the beta 4, alpha 6 integrin, as well as a novel 98-kD glycoprotein, and probably reacts with a carbohydrate epitope on these molecules. Involvement of the L280 antigen in cellular immunity is not restricted to NK cell-mediated cytotoxicity. L280 mAb also efficiently inhibits alloantigen-specific cytotoxicity against Colo-205 cells mediated by human histocompatibility leukocyte antigen (HLA)-A2 alloantigen specific alpha beta-TCR+ and gamma delta-TCR+ cytotoxic T lymphocyte (CTL) clones. Additionally, we demonstrate that L280 mAb blocks cytotoxicity mediated by influenza peptide-specific HLA-restricted CTL clones. These data indicate that the antigen recognized by L280 mAb is important in both NK and CTL function, and that an as yet unidentified receptor for this epithelial antigen is present on both NK and T lymphocytes. The restricted expression of L280 antigen indicates that this molecule may be important in immune reactions in epithelial tissues. PMID:1744585

  12. Identification of Immunogenic Cytotoxic T Lymphocyte Epitopes Containing Drug Resistance Mutations in Antiretroviral Treatment-Naïve HIV-Infected Individuals

    PubMed Central

    Blanco-Heredia, Juan; Lecanda, Aarón; Valenzuela-Ponce, Humberto; Brander, Christian; Ávila-Ríos, Santiago; Reyes-Terán, Gustavo

    2016-01-01

    Background Therapeutic HIV vaccines may prove helpful to intensify antiretroviral treatment (ART) efficacy and may be an integral part of future cure strategies. Methods We examined IFN-gamma ELISpot responses to a panel of 218 HIV clade B consensus-based HIV protease-reverse transcriptase peptides, designed to mimic previously described and predicted cytotoxic T lymphocyte epitopes overlapping drug resistance (DR) positions, that either included the consensus sequence or the DR variant sequence, in 49 ART-naïve HIV-infected individuals. Next generation sequencing was used to assess the presence of minority DR variants in circulating viral populations. Results Although a wide spectrum of differential magnitudes of response to DR vs. WT peptide pairs was observed, responses to DR peptides were frequent and strong in the study cohort. No difference between the median magnitudes of response to DR vs. WT peptides was observed. Interestingly, of the 22 peptides that were recognized by >15% of the participants, two-thirds (64%) corresponded to DR peptides. When analysing responses per peptide pair per individual, responses to only WT (median 4 pairs/individual) or DR (median 6 pairs/individual) were more common than responses to both WT and DR (median 2 pairs/individual; p<0.001). While the presence of ELISpot responses to WT peptides was frequently associated with the presence of the corresponding peptide sequence in the patient’s virus (mean 68% of cases), responses to DR peptides were generally not associated with the presence of DR mutations in the viral population, even at low frequencies (mean 1.4% of cases; p = 0.0002). Conclusions Our data suggests that DR peptides are frequently immunogenic and raises the potential benefit of broadening the antigens included in a therapeutic vaccine approach to immunogenic epitopes containing common DR sequences. Further studies are needed to assess the quality of responses elicited by DR peptides. PMID:26808823

  13. Frequent and variable cytotoxic-T-lymphocyte escape-associated fitness costs in the human immunodeficiency virus type 1 subtype B Gag proteins.

    PubMed

    Boutwell, Christian L; Carlson, Jonathan M; Lin, Tien-Ho; Seese, Aaron; Power, Karen A; Peng, Jian; Tang, Yanhua; Brumme, Zabrina L; Heckerman, David; Schneidewind, Arne; Allen, Todd M

    2013-04-01

    Cytotoxic-T-lymphocyte (CTL) escape mutations undermine the durability of effective human immunodeficiency virus type 1 (HIV-1)-specific CD8(+) T cell responses. The rate of CTL escape from a given response is largely governed by the net of all escape-associated viral fitness costs and benefits. The observation that CTL escape mutations can carry an associated fitness cost in terms of reduced virus replication capacity (RC) suggests a fitness cost-benefit trade-off that could delay CTL escape and thereby prolong CD8 response effectiveness. However, our understanding of this potential fitness trade-off is limited by the small number of CTL escape mutations for which a fitness cost has been quantified. Here, we quantified the fitness cost of the 29 most common HIV-1B Gag CTL escape mutations using an in vitro RC assay. The majority (20/29) of mutations reduced RC by more than the benchmark M184V antiretroviral drug resistance mutation, with impacts ranging from 8% to 69%. Notably, the reduction in RC was significantly greater for CTL escape mutations associated with protective HLA class I alleles than for those associated with nonprotective alleles. To speed the future evaluation of CTL escape costs, we also developed an in silico approach for inferring the relative impact of a mutation on RC based on its computed impact on protein thermodynamic stability. These data illustrate that the magnitude of CTL escape-associated fitness costs, and thus the barrier to CTL escape, varies widely even in the conserved Gag proteins and suggest that differential escape costs may contribute to the relative efficacy of CD8 responses. PMID:23365420

  14. Adeno-Associated Virus Type 2 (AAV2) Capsid-Specific Cytotoxic T Lymphocytes Eliminate Only Vector-Transduced Cells Coexpressing the AAV2 Capsid In Vivo▿

    PubMed Central

    Li, Chengwen; Hirsch, Matthew; Asokan, Aravind; Zeithaml, Brian; Ma, Hong; Kafri, Tal; Samulski, R. Jude

    2007-01-01

    A recent clinical trial has suggested that recombinant adeno-associated virus (rAAV) vector transduction in humans induces a cytotoxic T-lymphocyte (CTL) response against the AAV2 capsid. To directly address the ability of AAV capsid-specific CTLs to eliminate rAAV-transduced cells in vitro and in vivo in mice, we first demonstrated that AAV2 capsid-specific CTLs could be induced by dendritic cells with endogenous AAV2 capsid expression or pulsed with AAV2 vectors. These CTLs were able to kill a cell line stable for capsid expression in vitro and also in a mouse tumor xenograft model in vivo. Parent colon carcinoma (CT26) cells transduced with a large amount of AAV2 vectors in vitro were also destroyed by these CTLs. To determine the effect of CTLs on the elimination of target cells transduced by AAV2 vectors in vivo, we carried out adoptive transfer experiments. CTLs eliminated liver cells with endogenous AAV2 capsid expression but not liver cells transduced by AAV2 vectors, regardless of the reporter genes. Similar results were obtained for rAAV2 transduction in muscle. Our data strongly suggest that AAV vector-transduced cells are rarely eliminated by AAV2 capsid-specific CTLs in vivo, even though the AAV capsid can induce a CTL response. In conclusion, AAV capsid-specific CTLs do not appear to play a role in elimination of rAAV-transduced cells in a mouse model. In addition, our data suggest that the mouse model may not mimic the immune response noted in humans and additional modification to AAV vectors may be required for further study in order to elicit a similar cellular immune response. PMID:17475652

  15. Adeno-associated virus type 2 (AAV2) capsid-specific cytotoxic T lymphocytes eliminate only vector-transduced cells coexpressing the AAV2 capsid in vivo.

    PubMed

    Li, Chengwen; Hirsch, Matthew; Asokan, Aravind; Zeithaml, Brian; Ma, Hong; Kafri, Tal; Samulski, R Jude

    2007-07-01

    A recent clinical trial has suggested that recombinant adeno-associated virus (rAAV) vector transduction in humans induces a cytotoxic T-lymphocyte (CTL) response against the AAV2 capsid. To directly address the ability of AAV capsid-specific CTLs to eliminate rAAV-transduced cells in vitro and in vivo in mice, we first demonstrated that AAV2 capsid-specific CTLs could be induced by dendritic cells with endogenous AAV2 capsid expression or pulsed with AAV2 vectors. These CTLs were able to kill a cell line stable for capsid expression in vitro and also in a mouse tumor xenograft model in vivo. Parent colon carcinoma (CT26) cells transduced with a large amount of AAV2 vectors in vitro were also destroyed by these CTLs. To determine the effect of CTLs on the elimination of target cells transduced by AAV2 vectors in vivo, we carried out adoptive transfer experiments. CTLs eliminated liver cells with endogenous AAV2 capsid expression but not liver cells transduced by AAV2 vectors, regardless of the reporter genes. Similar results were obtained for rAAV2 transduction in muscle. Our data strongly suggest that AAV vector-transduced cells are rarely eliminated by AAV2 capsid-specific CTLs in vivo, even though the AAV capsid can induce a CTL response. In conclusion, AAV capsid-specific CTLs do not appear to play a role in elimination of rAAV-transduced cells in a mouse model. In addition, our data suggest that the mouse model may not mimic the immune response noted in humans and additional modification to AAV vectors may be required for further study in order to elicit a similar cellular immune response.

  16. Association of Cytotoxic T-Lymphocyte-Associated Protein 4 (CTLA4) Gene Polymorphisms with Autoimmune Thyroid Disease in Children and Adults: Case-Control Study.

    PubMed

    Ting, Wei-Hsin; Chien, Ming-Nan; Lo, Fu-Sung; Wang, Chao-Hung; Huang, Chi-Yu; Lin, Chiung-Ling; Lin, Wen-Shan; Chang, Tzu-Yang; Yang, Horng-Woei; Chen, Wei-Fang; Lien, Ya-Ping; Cheng, Bi-Wen; Lin, Chao-Hsu; Chen, Chia-Ching; Wu, Yi-Lei; Hung, Chen-Mei; Li, Hsin-Jung; Chan, Chon-In; Lee, Yann-Jinn

    2016-01-01

    Autoimmune thyroid disease (AITD), including Graves disease (GD) and Hashimoto disease (HD), is an organ-specific autoimmune disease with a strong genetic component. Although the cytotoxic T-lymphocyte-associated protein 4 (CTLA4) polymorphism has been reported to be associated with AITD in adults, few studies have focused on children. The aim of our study was to investigate whether the CTLA4 polymorphisms, including -318C/T (rs5742909), +49A/G (rs231775), and CT60 (rs3087243), were associated with GD and HD in Han Chinese adults and children. We studied 289 adult GD, 265 pediatric GD, 229 pediatric HD patients, and 1058 healthy controls and then compared genotype, allele, carrier, and haplotype frequencies between patients and controls. We found that CTLA4 SNPs +49A/G and CT60 were associated with GD in adults and children. Allele G of +49A/G was significantly associated with GD in adults (odds ratio [OR], 1.50; 95% confidence interval [CI], 1.21-1.84; corrected P value [Pc] < 0.001) and children (OR, 1.42; 95% CI, 1.15-1.77; Pc = 0.002). Allele G of CT60 also significantly increased risk of GD in adults (OR, 1.63; 95% CI, 1.27-2.09; Pc < 0.001) and GD in children (OR, 1.58; 95% CI, 1.22-2.04; Pc < 0.001). Significant linkage disequilibrium was found between +49A/G and CT60 in GD and control subjects (D' = 0.92). Our results showed that CTLA4 was associated with both GD and HD and played an equivalent role in both adult and pediatric GD in Han Chinese population. PMID:27111218

  17. Polymorphism within the herpes simplex virus (HSV) ribonucleotide reductase large subunit (ICP6) confers type specificity for recognition by HSV type 1-specific cytotoxic T lymphocytes.

    PubMed Central

    Salvucci, L A; Bonneau, R H; Tevethia, S S

    1995-01-01

    A panel of herpes simplex virus type 1 (HSV-1)-specific, CD8+, major histocompatibility complex class I (H-2Kb)-restricted cytotoxic T-lymphocyte (CTL) clones was derived from HSV-1-immunized C57BL/6 (H-2b) mice in order to identify the HSV-1 CTL recognition epitope(s) which confers type specificity. HSV-1 x HSV-2 intertypic recombinants were used to narrow the region encoding potential CTL recognition epitopes to within 0.51 to 0.58 map units of the HSV-1 genome. Using an inhibitor of viral DNA synthesis and an ICP6 deletion mutant, the large subunit of ribonucleotide reductase (ICP6, RR1) was identified as a target protein for these type-specific CTL. Potential CTL recognition epitopes within RR1 were located on the basis of the peptide motif predicted to bind to the MHC class I H-2Kb molecule. A peptide corresponding to residues 822 to 829 of RR1 was shown to confer susceptibility on H-2Kb-expressing target cells to lysis by the type 1-specific CTL. On the basis of a comparison of the HSV-1 RR1 epitope (residues 822 to 829) with the homologous sequence of HSV-2 RR1 (residues 828 to 836) and by the use of amino acid substitutions within synthetic peptides, we identified HSV-1 residue 828 as being largely responsible for the type specificity exhibited by HSV-1-specific CTL. This HSV-1 RR1 epitope, when expressed in recombinant simian virus 40 large T antigen in primary C57BL/6 cells, was recognized by the HSV-1 RR1-specific CTL clones. These results indicate that an early HSV protein with enzymatic activity provides a target for HSV-specific CTL and that type specificity is dictated largely by a single amino acid. PMID:7529328

  18. Comparative analysis of core amino acid residues of H-2D(b)-restricted cytotoxic T-lymphocyte recognition epitopes in simian virus 40 T antigen.

    PubMed Central

    Deckhut, A M; Lippolis, J D; Tevethia, S S

    1992-01-01

    Simian virus 40 (SV40) tumor (T) antigen expressed in H-2b SV40-transformed cells induces the generation of Lyt-2+ (CD8+) cytotoxic T lymphocytes (CTL), which are involved in tumor rejection, in syngeneic mice. Five CTL recognition sites on T antigen have been described by using mutant T antigens. Four of the sites (I, II, III, and V) are H-2Db restricted and have been broadly mapped with synthetic peptides of 15 amino acids in length overlapping by 5 residues at the amino and carboxy termini. The goal of this study was to define the minimal and optimal amino acid sequences of T antigen which would serve as recognition elements for the H-2Db-restricted CTL clones Y-1, Y-2, Y-3, and Y-5, which recognizes sites I, II, III, and V, respectively. The minimal and optimal residues of T antigen recognized by the four CTL clones were determined by using synthetic peptides truncated at the amino or carboxy terminus and an H-2Db peptide-binding motif. The minimal site recognized by CTL clone Y-1 was defined as amino acids 207 to 215 of SV40 T antigen. However, the optimal sequence recognized by CTL clone Y-1 spanned T-antigen amino acids 205 to 215. The T-antigen peptide sequence LT223-231 was the optimal and minimal sequence recognized by both CTL clones Y-2 and Y-3. Site V was determined to be contained within amino acids 489 to 497 of T antigen. The lytic activities of CTL clones Y-2 and Y-3, which recognize a single nonamer peptide, LT223-231, were affected differently by anti-Lyt-2 antibody, suggesting that the T-cell receptors of these two CTL clones differ in their avidities. As the minimal and optimal H-2Db-restricted CTL recognition sites have been defined by nonamer synthetic peptides, it is now possible to search for naturally processed H-2Db-restricted epitopes of T antigen and identify critical residues involved in processing, presentation, and recognition by SV40-specific CTL. PMID:1370091

  19. A matrix metalloproteinase inhibitor enhances anti-cytotoxic T lymphocyte antigen-4 antibody immunotherapy in breast cancer by reprogramming the tumor microenvironment

    PubMed Central

    LI, MINGYUE; XING, SHUGANG; ZHANG, HAIYING; SHANG, SIQI; LI, XIANGXIANG; REN, BO; LI, GAIYUN; CHANG, XIAONA; LI, YILEI; LI, WEI

    2016-01-01

    Anti-cytotoxic T lymphocyte antigen-4 (CTLA-4) treatment is effective for the treatment of primary tumors, but not sufficient for the treatment of metastatic tumors, likely owing to the effects of the tumor microenvironment. In this study, we aimed to determine the therapeutic effects of combined treatment with a matrix metalloproteinase (MMP) inhibitor (MMPI) and anti-CTLA-4 antibody in a breast cancer model in mice. Interestingly, combined treatment with MMPI and anti-CTLA-4 antibody delayed tumor growth and reduced lung and liver metastases compared with anti-CTLA-4 alone or vehicle treatment. The functions of the liver and kidney in mice in the different groups did not differ significantly compared with that in normal mice. The CD8+/CD4+ ratio in T cells in the spleen and tumor were increased after monotherapy or combined anti-CTLA-4 antibody plus MMPI therapy compared with that in vehicle-treated mice. Anti-CTLA-4 antibody plus MMPI therapy reduced the percentage of regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) and decreased the Treg/Th17 cell ratio in the spleen compared with those in the vehicle-treated group. Additionally, anti-CTLA-4 antibody plus MMPI therapy reduced the percentages of regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs), and Th17 cells in tumors compared with that in the vehicle-treated group. Moreover, combined treatment with MMPI and anti-CTLA-4 antibody reduced the microvessel density (MVD) in tumors compared with that in vehicle or MMPI-treated mice. There was a negative correlation between MVD and the CD8+ T cell percentage, CD4+ T cell percentage, and CD8+/CD4+ T cell ratio, but a positive correlation with Tregs, Th17 cells, Treg/Th17 cell ratio, and MDSCs. Thus, these data demonstrated that addition of MMPI enhanced the effects of anti-CTLA-4 antibody treatment in a mouse model of breast cancer by delaying tumor growth and reducing metastases. PMID:26752000

  20. In vitro migration of cytotoxic T lymphocyte derived from a colon carcinoma patient is dependent on CCL2 and CCR2

    PubMed Central

    2011-01-01

    Background Infiltration of colorectal carcinomas (CRC) with T-cells has been associated with good prognosis. There are some indications that chemokines could be involved in T-cell infiltration of tumors. Selective modulation of chemokine activity at the tumor site could attract immune cells resulting in tumor growth inhibition. In mouse tumor model systems, gene therapy with chemokines or administration of antibody (Ab)-chemokine fusion proteins have provided potent immune mediated tumor rejection which was mediated by infiltrating T cells at the tumor site. To develop such immunotherapeutic strategies for cancer patients, one must identify chemokines and their receptors involved in T-cell migration toward tumor cells. Methods To identify chemokine and chemokine receptors involved in T-cell migration toward CRC cells, we have used our previously published three-dimensional organotypic CRC culture system. Organotypic culture was initiated with a layer of fetal fibroblast cells mixed with collagen matrix in a 24 well tissue culture plate. A layer of CRC cells was placed on top of the fibroblast-collagen layer which was followed by a separating layer of fibroblasts in collagen matrix. Anti-CRC specific cytotoxic T lymphocytes (CTLs) mixed with fibroblasts in collagen matrix were placed on top of the separating layer. Excess chemokine ligand (CCL) or Abs to chemokine or chemokine receptor (CCR) were used in migration inhibition assays to identify the chemokine and the receptor involved in CTL migration. Results Inclusion of excess CCL2 in T-cell layer or Ab to CCL2 in separating layer of collagen fibroblasts blocked the migration of CTLs toward tumor cells and in turn significantly inhibited tumor cell apoptosis. Also, Ab to CCR2 in the separating layer of collagen and fibroblasts blocked the migration of CTLs toward tumor cells and subsequently inhibited tumor cell apoptosis. Expression of CCR2 in four additional CRC patients' lymphocytes isolated from infiltrating

  1. Recognition of HLA-A2 mutant and variant target cells by an HLA-A2 allospecific human cytotoxic T lymphocyte line.

    PubMed

    Ware, C F; Krangel, M S; Pious, D; Burakoff, S J; Strominger, J L

    1983-09-01

    HLA-A2 specific human cytotoxic T lymphocytes (CTL) cell lines have been developed using T cell growth factor and coculture of peripheral blood lymphocytes with selected allogeneic target cell lines. The CTL-8 line showed specificity for human leukocyte antigens (HLA)-A2 bearing target cells after 5 weeks in culture when tested against a panel of 14 lymphoblastoid cell lines in a 51Chromium (51Cr) release assay. Purified anti-human leukocyte antigens (HLA) monoclonal antibodies W6/32 and PA2.1 inhibited cytolysis by 85% and 60%, respectively. The CTL-8 line lysed non-HLA-A2 target cells in the presence of lectins concanavalin A (Con A) or phytohemagglutinin-P lectin (PHA-P) indicating the specificity of cytolysis was not due to nonspecific resistance of target cells to the CTL-lytic mechanism. The T5-1 HLA-A2 mutant cell series were tested as targets for the CTL-8 line. Cell clones 8.18.1, 8.21.1 and 8.6.1, which express altered HLA-A2 molecules as determined by their decreased reactivity with allospecific monoclonal antibodies, were lysed by the CTL-8 line as efficiently as the T5-1 wild type. These cell lines also acted as efficient cold target competitors for a normal HLA-A2 target cell. The 8.14.1 cell clone expressed a lower amount of HLA-A2 alloantigen and showed a corresponding decreased reactivity with CTL-8 in direct cytolytic and cold target competitive inhibition assays. In contrast, the M7 and DK1 HLA-A2 variant cell lines, which express normal HLA-A2 serological determinants, were inefficiently lysed by CTL-8 and did not act as competitive inhibitors of normal HLA-A2 target cells. These results support the concept that the alloantigenic determinant(s) recognized by T cells and antibodies occur at separate regions on the HLA-A2 molecule. PMID:6193184

  2. Calreticulin acts as an adjuvant to promote dendritic cell maturation and enhances antigen-specific cytotoxic T lymphocyte responses against non-small cell lung cancer cells.

    PubMed

    Liu, Xinli; Li, Jijia; Liu, Yu; Ding, Jianqiao; Tong, Zhuang; Liu, Yang; Zhou, Yang; Liu, Yongyu

    2016-02-01

    Dendritic cell (DC)-based immunotherapy has promising for treatment of non-small cell lung cancer (NSCLC). Melanoma-associated antigen 3 (MAGE-A3) is a tumor-specific antigen and expressed in approximately 35-40% of NSCLC tissues. Calreticulin (CALR) is a protein chaperone and can enhance DC maturation and antigen presentation. In this study, we evaluated the adjuvant activity of CALR in human DC maturation and their capacity to induce MAGE-A3-specific CD8+ cytotoxic T lymphocyte (CTL) responses to NSCLC in vitro. Infection with recombinant Ad-CALR and/or Ad-MAGE-A3, but not with control Ads, induced CALR and/or MAGE-A3 expression in DCs. Infection with Ad-CALR significantly increased the percentages of CD80+, CD83+, CD86+ and HLA-DR+ DCs and IL-12 secretion, but reduced IL-10 production in DCs. Co-culture of autologous lymphocytes with DC-Ad-CALR or DC-Ad-CM significantly increased the numbers of induced CD8+ CTLs. The percentages of IFNγ-secreting CTLs responding to SK-LU-1 and NCI-H522 NSCLC, but not to non-tumor NL-20 cells in Ad-C-CTL, Ad-M-CTL and Ad-CM-CTL were significantly higher than that of DC-CTL and Ad-null-CTL. Ad-C-CTL, Ad-M-CTL and Ad-CM-CTL, but not control DC-CTL and Ad-null-CTL, induced higher frequency of MAGE-A3+HLA-A2+ NCI-H-522 cell apoptosis, but did not affect the survival of MAGE-A3+HLA-A2- SK-LU-1 and non-tumor NL20 cells in vitro. Treatment with anti-HLA-I antibody, but not with anti-HLA-II, dramatically diminished the cytotoxicity of Ad-CM-CTLs against NCI-H522 cells. Our data indicated that CALR acted as an adjuvant to promote DC maturation, which induced CTL development and enhanced MAGE-A3-specific CTL cytotoxicity against NSCLC.

  3. Different Effects of Nonnucleoside Reverse Transcriptase Inhibitor Resistance Mutations on Cytotoxic T Lymphocyte Recognition between HIV-1 Subtype B and Subtype A/E Infections

    PubMed Central

    Kuse, Nozomi; Rahman, Mohammad Arif; Murakoshi, Hayato; Tran, Giang Van; Chikata, Takayuki; Koyanagi, Madoka; Nguyen, Kinh Van; Gatanaga, Hiroyuki; Oka, Shinichi

    2015-01-01

    ABSTRACT The effect of antiretroviral drug resistance mutations on cytotoxic T lymphocyte (CTL) recognition has been analyzed in HIV-1 subtype B infections, but it remains unclear in infections by other HIV-1 subtypes that are epidemic in countries where antiretroviral drugs are not effectively used. We investigated the effect of nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI)-resistance mutations (Y181C, Y181I, and Y181V) on epitope recognition by CTLs specific for 3 different HIV-1 epitopes (HLA-A*02:01-restricted IV10, HLA-B*35:01-restricted NY9, and HLA-C*12:02-restricted KY9) in subtype B and subtype A/E infections and the accumulation of these mutations in treatment-naive Japanese and Vietnamese. These NNRTI-resistance mutations critically affected NY9-specific and KY9-specific T cell responses in the subtype B infections, whereas they showed a different effect on IV10-specific T cell responses among the subtype B-infected individuals. These mutations affected IV10-specific T cell responses but weakly affected NY9-specific T cell responses in the subtype A/E infections. The substitution at position 3 of NY9 epitope which was found in the subtype A/E virus differently influenced the peptide binding to HLA-B*35:01, suggesting that the differences in peptide binding may result in the differences in T cell recognition between the subtype B virus and A/E virus infections. The Y181C mutation was found to be accumulating in treatment-naive Vietnamese infected with the subtype A/E virus. The present study demonstrated different effects of NNRTI-resistance RT181 mutations on CTL responses between the 2 subtype infections. The Y181C mutation may influence HIV-1 control by the CTLs in Vietnam, since this mutation has been accumulating in treatment-naive Vietnamese. IMPORTANCE Antiretroviral therapy leads to the emergence of drug-resistant HIV-1, resulting in virological and clinical failures. Though HIV-1-specific CTLs play a critical role in HIV-1 infection

  4. Ex vivo expansion of polyclonal and antigen-specific cytotoxic T lymphocytes by artificial APCs expressing ligands for the T-cell receptor, CD28 and 4-1BB.

    PubMed

    Maus, Marcela V; Thomas, Anna K; Leonard, Debra G B; Allman, David; Addya, Kathakali; Schlienger, Katia; Riley, James L; June, Carl H

    2002-02-01

    The ex vivo priming and expansion of human cytotoxic T lymphocytes (CTLs) has potential for use in immunotherapy applications for cancer and infectious diseases. To overcome the difficulty in obtaining sufficient numbers of CTLs, we have developed artificial antigen-presenting cells (aAPCs) expressing ligands for the T-cell receptor (TCR) and the CD28 and 4-1BB co-stimulatory surface molecules. These aAPCs reproducibly activate and rapidly expand polyclonal or antigen-specific CD8(+) T cells. The starting repertoire of CD8+ T cells was preserved during culture. Furthermore, apoptosis of cultured CD8(+) T cells was diminished by this approach. This approach may have important therapeutic implications for adoptive immunotherapy. PMID:11821859

  5. Circulating anti-Tax cytotoxic T lymphocytes from human T-cell leukemia virus type I-infected people, with and without tropical spastic paraparesis, recognize multiple epitopes simultaneously.

    PubMed Central

    Parker, C E; Nightingale, S; Taylor, G P; Weber, J; Bangham, C R

    1994-01-01

    CD8+ T cells were freshly isolated from a human T-cell leukemia virus type I (HTLV-I)-infected patient with tropical spastic paraparesis. These cells, which were specific for HTLV-I Tax, simultaneously recognized a minimum of five, and possibly as many as seven, distinct peptide epitopes within the protein. A further Tax epitope was recognized after a short period of culture without exogenous peptide stimulation. All but one of these epitopes were clustered in the N-terminal third of Tax, and one of the epitopes was clearly immunodominant on two separate occasions of testing. Recognition of the immunodominant epitope was restricted by human leukocyte antigen (HLA) B15, and recognition of all the others was by HLA A2. Similar patterns of cytotoxic T lymphocyte recognition of the HLA A2-restricted Tax peptides in two healthy HTLV-I-seropositive individuals, each of whom carried the HLA A2 allele, were observed. PMID:7512153

  6. TLR agonists are highly effective at eliciting functional memory CTLs of effector memory phenotype in peptide immunization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Given the importance of memory cytotoxic T lymphocytes (CTLs) in eliminating altered self-cells, including virus-infected and tumor cells, devising effective vaccination strategies for generating memory CTLs is a priority in the field of immunology. Herein, we elaborate upon a novel boosting approac...

  7. Cytotoxic minor histocompatibility antigen HA-1-specific CD8+ effector memory T cells: artificial APCs pave the way for clinical application by potent primary in vitro induction.

    PubMed

    Schilbach, Karin; Kerst, Gunter; Walter, Steffen; Eyrich, Matthias; Wernet, Dorothee; Handgretinger, Rupert; Xie, Weidong; Rammensee, Hans-Georg; Müller, Ingo; Bühring, Hans-Jörg; Niethammer, Dietrich

    2005-07-01

    Induction of cytotoxic T lymphocytes (CTLs) for treatment of relapsed leukemia after allogeneic stem-cell transplantation is hindered by the laborious and time-consuming procedure of generating dendritic cells for antigen presentation. Artificial antigen-presenting cells (aAPCs) offer the advantage of being readily available in sufficient numbers, thus allowing for a highly standardized in vitro induction of CTLs. We generated aAPCs coated with anti-CD28 antibody (Ab) and either high-density (HD) or low-density (LD) major histocompatibility complex (MHC) class I molecules loaded with HA-1(H), a nonapeptide derived from the hematopoiesis-restricted minor histocompatibility antigen HA-1. HD- and LD-aAPCs potently induced HA-1(H)-specific CD8+ CTLs from untouched CD8+ T cells of healthy donors. CTLs were subsequently purified by magnetic-activated cell sorting. HD- as well as LD-aAPC-induced CTLs exerted high HA-1H-specific cytotoxicity, resembled T(c)1 effector memory cells, survived a long time in vitro, and were expanded by a factor varying between 8.2 x 10(4) and 51 x 10(4). The T-cell receptor (TCR) repertoire of HA-1H tetramer-positive CTLs was oligoclonal with a prominent usage of Vbeta6. The TCR repertoire of tetramer-positive CTLs was distinct from and more restricted than that of tetramer-negative cells. These findings indicate that aAPCs are attractive tools for the ex vivo generation of HA-1H-specific CTLs suitable for immunotherapy of relapsed leukemia. PMID:15731181

  8. Detailed analysis of immunologic effects of the cytotoxic T lymphocyte-associated antigen 4-blocking monoclonal antibody tremelimumab in peripheral blood of patients with melanoma

    PubMed Central

    Comin-Anduix, Begoña; Lee, Yohan; Jalil, Jason; Algazi, Alain; de la Rocha, Pilar; Camacho, Luis H; Bozon, Viviana A; Bulanhagui, Cecile A; Seja, Elisabeth; Villanueva, Arturo; Straatsma, Bradley R; Gualberto, Antonio; Economou, James S; Glaspy, John A; Gomez-Navarro, Jesus; Ribas, Antoni

    2008-01-01

    Background CTLA4-blocking antibodies induce tumor regression in a subset of patients with melanoma. Analysis of immune parameters in peripheral blood may help define how responses are mediated. Methods Peripheral blood from HLA-A*0201-positive patients with advanced melanoma receiving tremelimumab (formerly CP-675,206) at 10 mg/kg monthly was repeatedly sampled during the first 4 cycles. Samples were analyzed by 1) tetramer and ELISPOT assays for reactivity to CMV, EBV, MART1, gp100, and tyrosinase; 2) activation HLA-DR and memory CD45RO markers on CD4+/CD8+ cells; and 3) real-time quantitative PCR of mRNA for FoxP3 transcription factor, preferentially expressed by T regulatory cells. The primary endpoint was difference in MART1-specific T cells by tetramer assay. Immunological data were explored for significant trends using clustering analysis. Results Three of 12 patients eligible for immune monitoring had tumor regression lasting > 2 years without relapse. There was no significant change in percent of MART1-specific T cells by tetramer assay. Additionally, there was no generalized trend toward postdosing changes in other antigen-specific CD8+ cell populations, FoxP3 transcripts, or overall changes in surface expression of T-cell activation or memory markers. Unsupervised hierarchical clustering based on immune monitoring data segregated patients randomly. However, clustering according to T-cell activation or memory markers separated patients with clinical response and most patients with inflammatory toxicity into a common subgroup. Conclusion Administration of CTLA4-blocking antibody tremelimumab to patients with advanced melanoma results in a subset of patients with long-lived tumor responses. T-cell activation and memory markers served as the only readout of the pharmacodynamic effects of this antibody in peripheral blood. Clinical trial registration number NCT00086489 PMID:18452610

  9. The relative resistance of HIV type 1-infected chimpanzees to AIDS correlates with the maintenance of follicular architecture and the absence of infiltration by CD8+ cytotoxic T lymphocytes.

    PubMed

    Koopman, G; Haaksma, A G; ten Velden, J; Hack, C E; Heeney, J L

    1999-03-01

    Lymphoid tissues are the focus of critical events in HIV pathogenesis. Persistent and high levels of virus production, extensive trapping of virus particles in germinal centers, and progressive degenerative changes in lymph node architecture are characteristics of progressive HIV-1 infection. Infiltrates of granzyme B- and TIA-expressing CD8+ "cytotoxic" T lymphocytes (CTLs) precede involution of germinal centers in humans who develop AIDS. Similar to humans, HIV-1 infection in chimpanzees is active and persistent. However, in contrast to humans, they remain relatively resistant to AIDS. Lymph node biopsies from chimpanzees infected with HIV-1 or a related chimpanzee lentivirus were studied for the level and pattern of virus expression, changes in lymphoid architecture, CD8+ T cell infiltrates and the presence or absence of CTL markers. In stark contrast to HIV-1-infected humans, lymph nodes from infected chimpanzees had little virus deposition in germinal centers and a paucity of virus-expressing cells. Although some of the lymph nodes examined from infected animals had moderate follicular hyperplasia with infiltrating CD8+ T cells, none had evidence of follicular fragmentation. Most importantly, in marked contrast to infected humans, CD8+ T cells infiltrating the germinal center were negative for the CTL marker granzyme B. This evidence suggests that the infiltration of CD8+ CTLs into the germinal centers of lymph nodes may be a key determinant in AIDS pathogenesis.

  10. Salmonella typhimurium delta aroA delta aroD mutants expressing a foreign recombinant protein induce specific major histocompatibility complex class I-restricted cytotoxic T lymphocytes in mice.

    PubMed Central

    Turner, S J; Carbone, F R; Strugnell, R A

    1993-01-01

    Recombinant Salmonella typhimurium aroA aroD mutants which expressed ovalbumin were constructed. The two expression constructs used were based on either pUC18 or pBR322. The pBR322-based construct was more stable in vitro and in vivo than the pUC-based construct. Salmonellae containing the stable pBR322-based plasmid induced major histocompatibility complex (MHC) class I-restricted cytotoxic T lymphocytes (CTL), in contrast to salmonellae containing the pUC18-based expression construct. The priming of MHC class I-restricted CTL was increased by multiple immunizations. The study described in this report suggest that S. typhimurium delta aro mutants have the capacity to induce MHC class I-restricted CTL against carried antigens and that MHC class I-restricted CTL responses require stable in vivo expression of the target antigen. Further, the results indicate that the Salmonella typhi delta aro mutants currently undergoing evaluation in studies with humans may be good carriers of viral antigens with CTL determinants. Images PMID:8225611

  11. Evaluation of the ability of N-terminal fragment of lethal factor of Bacillus anthracis for delivery of Mycobacterium T cell antigen ESAT-6 into cytosol of antigen presenting cells to elicit effective cytotoxic T lymphocyte response

    SciTech Connect

    Chandra, Subhash; Kaur, Manpreet; Midha, Shuchi; Bhatnagar, Rakesh . E-mail: rakbhat01@yahoo.com; Banerjee-Bhatnagar, Nirupama . E-mail: nirupama@icgeb.res.in

    2006-12-22

    We report the ability of N-terminal fragment of lethal factor of Bacillus anthracis to deliver genetically fused ESAT-6 (early secretory antigen target), a potent T cell antigen of Mycobacterium tuberculosis, into cytosol to elicit Cytotoxic T lymphocyte (CTL) response. In vitro Th1 cytokines data and CTL assay proved that efficient delivery of LFn.ESAT-6 occurs in cytosol, in the presence of protective antigen (PA), and leads to generation of effective CTL response. Since CTL response is essential for protection against intracellular pathogens and, it is well known that only single T cell epitope or single antigenic protein is not sufficient to elicit protective CTL response due to variation or polymorphism in MHC-I alleles among the individuals, we suggest that as a fusion protein LFn can be used to deliver multiepitopes of T cells or multiproteins which can generate effective CTLs against intracellular pathogens like M. tuberculosis. It can be used to enhance the protective efficacy of BCG vaccine.

  12. T cell receptor genes in a series of class I major histocompatibility complex-restricted cytotoxic T lymphocyte clones specific for a Plasmodium berghei nonapeptide: implications for T cell allelic exclusion and antigen-specific repertoire

    PubMed Central

    1991-01-01

    We report here the first extensive study of a T cell repertoire for a class I major histocompatibility complex (MHC)-restricted cytotoxic T lymphocyte (CTL) response. We have found that the T cell receptors (TCRs) carried by 28 H-2Kd-restricted CTL clones specific for a single Plasmodium berghei circumsporozoite nonapeptide are highly diverse in terms of V alpha, J alpha, and J beta segments and aminoacid composition of the junctional regions. However, despite this extensive diversity, a high proportion of the TCRs contain the same V beta segment. These results are in contrast to most previously reported T cell responses towards class II MHC-peptide complexes, where the TCR repertoires appeared to be much more limited. In our study, the finding of a dominant V beta in the midst of otherwise highly diverse TCRs suggests the importance of the V beta segment in shaping the T cell repertoire specific for a given MHC-peptide complex. As an additional finding, we observed that nearly all clones have rearranged both TCR alpha loci. Moreover, as many as one-third of the CTL clones that we analyzed apparently display two productive alpha rearrangements. This argues against a regulated model of sequential recombination at the alpha locus and consequently raises the question of whether allelic exclusion of the TCR alpha chain is achieved at all. PMID:1836010

  13. Identification of Novel HLA-A2-Restricted Human Immunodeficiency Virus Type 1-Specific Cytotoxic T-Lymphocyte Epitopes Predicted by the HLA-A2 Supertype Peptide-Binding Motif

    PubMed Central

    Altfeld, Marcus A.; Livingston, Brian; Reshamwala, Neha; Nguyen, Phuong T.; Addo, Marylyn M.; Shea, Amy; Newman, Mark; Fikes, John; Sidney, John; Wentworth, Peggy; Chesnut, Robert; Eldridge, Robert L.; Rosenberg, Eric S.; Robbins, Gregory K.; Brander, Christian; Sax, Paul E.; Boswell, Steve; Flynn, Theresa; Buchbinder, Susan; Goulder, Philip J. R.; Walker, Bruce D.; Sette, Alessandro; Kalams, Spyros A.

    2001-01-01

    Virus-specific cytotoxic T-lymphocyte (CTL) responses are critical in the control of human immunodeficiency virus type 1 (HIV-1) infection and will play an important part in therapeutic and prophylactic HIV-1 vaccines. The identification of virus-specific epitopes that are efficiently recognized by CTL is the first step in the development of future vaccines. Here we describe the immunological characterization of a number of novel HIV-1-specific, HLA-A2-restricted CTL epitopes that share a high degree of conservation within HIV-1 and a strong binding to different alleles of the HLA-A2 superfamily. These novel epitopes include the first reported CTL epitope in the Vpr protein. Two of the novel epitopes were immunodominant among the HLA-A2-restricted CTL responses of individuals with acute and chronic HIV-1 infection. The novel CTL epitopes identified here should be included in future vaccines designed to induce HIV-1-specific CTL responses restricted by the HLA-A2 superfamily and will be important to assess in immunogenicity studies in infected persons and in uninfected recipients of candidate HIV-1 vaccines. PMID:11152503

  14. Epstein-Barr Virus-Induced Gene 3 (EBI3) Blocking Leads to Induce Antitumor Cytotoxic T Lymphocyte Response and Suppress Tumor Growth in Colorectal Cancer by Bidirectional Reciprocal-Regulation STAT3 Signaling Pathway

    PubMed Central

    Liang, Yanfang; Chen, Qianqian; Du, Wenjing; Chen, Can; Li, Feifei; Yang, Jingying; Peng, Jianyu; Kang, Dongping; Lin, Bihua; Chai, Xingxing; Zhou, Keyuan; Zeng, Jincheng

    2016-01-01

    Epstein-Barr virus-induced gene 3 (EBI3) is a member of the interleukin-12 (IL-12) family structural subunit and can form a heterodimer with IL-27p28 and IL-12p35 subunit to build IL-27 and IL-35, respectively. However, IL-27 stimulates whereas IL-35 inhibits antitumor T cell responses. To date, little is known about the role of EBI3 in tumor microenvironment. In this study, firstly we assessed EBI3, IL-27p28, IL-12p35, gp130, and p-STAT3 expression with clinicopathological parameters of colorectal cancer (CRC) tissues; then we evaluated the antitumor T cell responses and tumor growth with a EBI3 blocking peptide. We found that elevated EBI3 may be associated with IL-12p35, gp130, and p-STAT3 to promote CRC progression. EBI3 blocking peptide promoted antitumor cytotoxic T lymphocyte (CTL) response by inducing Granzyme B, IFN-γ production, and p-STAT3 expression and inhibited CRC cell proliferation and tumor growth to associate with suppressing gp130 and p-STAT3 expression. Taken together, these results suggest that EBI3 may mediate a bidirectional reciprocal-regulation STAT3 signaling pathway to assist the tumor escape immune surveillance in CRC. PMID:27247488

  15. Markov modelling of changes in HIV-specific cytotoxic T-lymphocyte responses with time in untreated HIV-1 infected patients.

    PubMed

    Kousignian, I; Autran, B; Chouquet, C; Calvez, V; Gomard, E; Katlama, C; Rivière, Y; Costagliola, D

    2003-05-30

    HIV-specific cytotoxic CD8(+) T-lymphocytes (CTL) appear to be the cornerstone of the immune response to HIV infection. Recent studies show that CTL activity reflects patients' anti-HIV immune status and slows disease progression. However, the dynamics of the diversity of this response also appears as a key parameter for immune control but the dynamics of this diversity is largely undocumented. We modelled changes in CTL responses against the seven principal HIV proteins over time. We also studied the influence of plasma viral load on temporal changes in HIV protein recognition by memory CTL. The generic model we developed is based on a continuous time homogeneous Markov process with reversible states. Those states are defined by the number of proteins recognized by memory CTL in a given patient at a given time. This approach was developed within a Bayesian framework. Full Bayesian inference is implemented using Markov chain Monte Carlo simulations (MCMC). The Gibbs sampling algorithm was used to estimate the marginal posterior distributions of the transition intensities between stages of CTL responses. We applied our model to data of 152 HIV-infected patients included in the IMMUNOCO cohort. The model suggested that the diversity of HIV protein recognition by memory CTL in treatment-naive patients decreases as the disease progresses. Namely, the loss of T cytotoxic responses is globally faster than their acquisition. Indeed, these patients' T cytotoxic responses were characterized by marked individual turnover and a gradual loss of multiple protein recognition over time, this loss accelerating as viral load increased. PMID:12720304

  16. Ceramide mediates FasL-induced caspase 8 activation in colon carcinoma cells to enhance FasL-induced cytotoxicity by tumor-specific cytotoxic T lymphocytes

    PubMed Central

    Coe, Genevieve L.; Redd, Priscilla S.; Paschall, Amy V.; Lu, Chunwan; Gu, Lilly; Cai, Houjian; Albers, Thomas; Lebedyeva, Iryna O.; Liu, Kebin

    2016-01-01

    FasL-mediated cytotoxicity is one of the mechanisms that CTLs use to kill tumor cells. However, human colon carcinoma often deregulates the Fas signaling pathway to evade host cancer immune surveillance. We aimed at testing the hypothesis that novel ceramide analogs effectively modulate Fas function to sensitize colon carcinoma cells to FasL-induced apoptosis. We used rational design and synthesized twenty ceramide analogs as Fas function modulators. Five ceramide analogs, IG4, IG7, IG14, IG17, and IG19, exhibit low toxicity and potent activity in sensitization of human colon carcinoma cells to FasL-induced apoptosis. Functional deficiency of Fas limits both FasL and ceramide analogs in the induction of apoptosis. Ceramide enhances FasL-induced activation of the MAPK, NF-κB, and caspase 8 despite induction of potent tumor cell death. Finally, a sublethal dose of several ceramide analogs significantly increased CTL-mediated and FasL-induced apoptosis of colon carcinoma cells. We have therefore developed five novel ceramide analogs that act at a sublethal dose to enhance the efficacy of tumor-specific CTLs, and these ceramide analogs hold great promise for further development as adjunct agents in CTL-based colon cancer immunotherapy. PMID:27487939

  17. Interleukin-7 treatment counteracts IFN-α therapy-induced lymphopenia and stimulates SIV-specific cytotoxic T lymphocyte responses in SIV-infected rhesus macaques.

    PubMed

    Parker, Raphaëlle; Dutrieux, Jacques; Beq, Stéphanie; Lemercier, Brigitte; Rozlan, Sandra; Fabre-Mersseman, Véronique; Rancez, Magali; Gommet, Céline; Assouline, Brigitte; Rancé, Iann; Lim, Annick; Morre, Michel; Cheynier, Rémi

    2010-12-16

    Interferon-α (IFN-α)-based therapy is presently the standard treatment for hepatitis C virus (HCV)-infected patients. Despite good effectiveness, this cytokine is associated with major side effects, including significant lymphopenia, that limits its use for HIV/HCV-coinfected patients. Interleukin-7 (IL-7) has recently shown therapeutic potential and safety in several clinical trials designed to demonstrate T-cell restoration in immunodeficient patients. The purpose of this study was to evaluate, in simian immunodeficiency virus-infected rhesus macaques, the relevance of IL-7 therapy as a means to overcoming IFN-α-induced lymphopenia. We showed that low-dose IFN-α treatment induced strong lymphopenia in chronically infected monkeys. In contrast, high-dose IFN-α treatment stimulated IL-7 production, leading to increased circulating T-cell counts. Moreover, IL-7 therapy more than abrogated the lymphopenic effect of low-dose IFN-α. Indeed, the association of both cytokines resulted in increased circulating T-cell counts, in particular in the naive compartments, as a consequence of central and peripheral homeostatic functions of the IL-7. Finally, reduced PD-1 expression by memory CD8(+) T cells and transient T-cell repertoire diversification were observed under IL-7 therapy. Our data strongly suggest that IL-7 immunotherapy will be of substantial benefit in the treatment of HIV/HCV coinfection and should enhance the likelihood of HCV eradication in poorly responding patients.

  18. Enhancement of the antigen-specific cytotoxic T lymphocyte-inducing ability in the PMDC11 leukemic plasmacytoid dendritic cell line via lentiviral vector-mediated transduction of the caTLR4 gene.

    PubMed

    Iwabuchi, Minami; Narita, Miwako; Uchiyama, Takayoshi; Iwaya, Shunpei; Oiwa, Eri; Nishizawa, Yoshinori; Hashimoto, Shigeo; Bonehill, Aude; Kasahara, Noriyuki; Takizawa, Jun; Takahashi, Masuhiro

    2015-08-01

    The aim of the present study was to enhance the efficiency of leukemia immunotherapy by increasing the antigen-specific cytotoxic T lymphocyte-inducing ability of leukemia cells. The leukemic plasmacytoid dendritic cell line PMDC05 containing the HLA-A02/24 antigen, which was previously established in our laboratory (Laboratory of Hematology and Oncology, Graduate School of Health Sciences, Niigata University, Niigata, Japan), was used in the present study. It exhibited higher expression levels of CD80 following transduction with lentiviruses encoding the CD80 gene. This CD80-expressing PMDC05 was named PMDC11. In order to establish a more potent antigen-presenting cell for cellular immunotherapy of tumors or severe infections, PMDC11 cells were transduced with a constitutively active (ca) toll-like receptor 4 (TLR4) gene using the Tet-On system (caTLR4-PMDC11). CD8(+) T cells from healthy donors with HLA-A02 were co-cultured with mutant WT1 peptide-pulsed PMDC11, lipopolysaccharide (LPS)-stimulated PMDC11 or caTLR4-PMDC11 cells. Interleukin (IL)-2 (50 IU/ml) and IL-7 (10 ng/ml) were added on day three of culture. Priming with mutant WT1 peptide-pulsed PMDC11, LPS-stimulated PMDC11 or caTLR4-PMDC11 cells was conducted once per week and two thirds of the IL-2/IL-7 containing medium was replenished every 3-4 days. Immediately prior to the priming with these various PMDC11 cells, the cultured cells were analyzed for the secretion of interferon (IFN)-γ in addition to the percentage and number of CD8(+)/WT1 tetramer(+) T cells using flow cytometry. caTLR4-PMDC11 cells were observed to possess greater antigen-presenting abilities compared with those of PMDC11 or LPS-stimulated PMDC11 cells in a mixed leukocyte culture. CD8 T cells positive for the WT1 tetramer were generated following 3-4 weeks of culture and CD8(+)/WT1 tetramer+ T cells were markedly increased in caTLR4-PMDC11-primed CD8(+) T cell culture compared with PMDC11 or LPS-stimulated PMDC11-primed CD8(+) T

  19. Enhancement of the antigen-specific cytotoxic T lymphocyte-inducing ability in the PMDC11 leukemic plasmacytoid dendritic cell line via lentiviral vector-mediated transduction of the caTLR4 gene

    PubMed Central

    IWABUCHI, MINAMI; NARITA, MIWAKO; UCHIYAMA, TAKAYOSHI; IWAYA, SHUNPEI; OIWA, ERI; NISHIZAWA, YOSHINORI; HASHIMOTO, SHIGEO; BONEHILL, AUDE; KASAHARA, NORIYUKI; TAKIZAWA, JUN; TAKAHASHI, MASUHIRO

    2015-01-01

    The aim of the present study was to enhance the efficiency of leukemia immunotherapy by increasing the antigen-specific cytotoxic T lymphocyte-inducing ability of leukemia cells. The leukemic plasmacytoid dendritic cell line PMDC05 containing the HLA-A02/24 antigen, which was previously established in our laboratory (Laboratory of Hematology and Oncology, Graduate School of Health Sciences, Niigata University, Niigata, Japan), was used in the present study. It exhibited higher expression levels of CD80 following transduction with lentiviruses encoding the CD80 gene. This CD80-expressing PMDC05 was named PMDC11. In order to establish a more potent antigen-presenting cell for cellular immunotherapy of tumors or severe infections, PMDC11 cells were transduced with a constitutively active (ca) toll-like receptor 4 (TLR4) gene using the Tet-On system (caTLR4-PMDC11). CD8+ T cells from healthy donors with HLA-A02 were co-cultured with mutant WT1 peptide-pulsed PMDC11, lipopolysaccharide (LPS)-stimulated PMDC11 or caTLR4-PMDC11 cells. Interleukin (IL)-2 (50 IU/ml) and IL-7 (10 ng/ml) were added on day three of culture. Priming with mutant WT1 peptide-pulsed PMDC11, LPS-stimulated PMDC11 or caTLR4-PMDC11 cells was conducted once per week and two thirds of the IL-2/IL-7 containing medium was replenished every 3–4 days. Immediately prior to the priming with these various PMDC11 cells, the cultured cells were analyzed for the secretion of interferon (IFN)-γ in addition to the percentage and number of CD8+/WT1 tetramer+ T cells using flow cytometry. caTLR4-PMDC11 cells were observed to possess greater antigen-presenting abilities compared with those of PMDC11 or LPS-stimulated PMDC11 cells in a mixed leukocyte culture. CD8 T cells positive for the WT1 tetramer were generated following 3–4 weeks of culture and CD8+/WT1 tetramer+ T cells were markedly increased in caTLR4-PMDC11-primed CD8+ T cell culture compared with PMDC11 or LPS-stimulated PMDC11-primed CD8+ T cell

  20. Cross-reactive lysis of human targets infected with prototypic and clinical human immunodeficiency virus type 1 (HIV-1) strains by murine anti-HIV-1 IIIB env-specific cytotoxic T lymphocytes.

    PubMed Central

    Chada, S; DeJesus, C E; Townsend, K; Lee, W T; Laube, L; Jolly, D J; Chang, S M; Warner, J F

    1993-01-01

    To evaluate the ability of murine anti-human immunodeficiency virus type 1 (HIV-1) IIIB env cytotoxic T lymphocytes (CTL) to recognize and lyse HIV-1-infected cells, we have constructed a human cell line (Hu/Dd) expressing both the CD4 receptor and the murine H-2Dd major histocompatibility complex (MHC) class I protein. This cell line can be productively infected with HIV-1 and can also function as a target for murine CD8+, class I MHC-restricted CTL directed against the envelope glycoprotein of HIV-1 IIIB. The ability of BALB/c anti-HIV-1 IIIB env CTL to specifically recognize and lyse Hu/Dd target cells infected with divergent HIV-1 strains was tested by using both prototypic and clinical HIV-1 strains. CTL generated by immunization of mice with syngeneic cells expressing either the native or V3 loop-deleted (delta V3) envelope glycoprotein from HIV-1 IIIB were able to recognize and specifically lyse Hu/Dd target cells infected with the HIV-1 prototypic isolates IIIB, MN, WMJ II, SF2, and CC as well as several HIV-1 clinical isolates. These results demonstrate that CTL determinants for HIV-1 env exist outside the hypervariable V3 region, anti-HIV-1 IIIB env CTL appear to recognize common determinants on diverse HIV-1 strains, and classification of HIV-1 strains based on neutralizing antibody reactivities does not appear to correspond to CTL recognition and lysis. The results suggest that the cell-mediated components of the immune system may have a broader recognition of divergent HIV-1 strains than do the humoral components. Images PMID:8497058

  1. Crystal structure of swine major histocompatibility complex class I SLA-1 0401 and identification of 2009 pandemic swine-origin influenza A H1N1 virus cytotoxic T lymphocyte epitope peptides.

    PubMed

    Zhang, Nianzhi; Qi, Jianxun; Feng, Sijia; Gao, Feng; Liu, Jun; Pan, Xiaocheng; Chen, Rong; Li, Qirun; Chen, Zhaosan; Li, Xiaoying; Xia, Chun; Gao, George F

    2011-11-01

    The presentation of viral epitopes to cytotoxic T lymphocytes (CTLs) by swine leukocyte antigen class I (SLA I) is crucial for swine immunity. To illustrate the structural basis of swine CTL epitope presentation, the first SLA crystal structures, SLA-1 0401, complexed with peptides derived from either 2009 pandemic H1N1 (pH1N1) swine-origin influenza A virus (S-OIV(NW9); NSDTVGWSW) or Ebola virus (Ebola(AY9); ATAAATEAY) were determined in this study. The overall peptide-SLA-1 0401 structures resemble, as expected, the general conformations of other structure-solved peptide major histocompatibility complexes (pMHC). The major distinction of SLA-1 0401 is that Arg(156) has a "one-ballot veto" function in peptide binding, due to its flexible side chain. S-OIV(NW9) and Ebola(AY9) bind SLA-1 0401 with similar conformations but employ different water molecules to stabilize their binding. The side chain of P7 residues in both peptides is exposed, indicating that the epitopes are "featured" peptides presented by this SLA. Further analyses showed that SLA-1 0401 and human leukocyte antigen (HLA) class I HLA-A 0101 can present the same peptides, but in different conformations, demonstrating cross-species epitope presentation. CTL epitope peptides derived from 2009 pandemic S-OIV were screened and evaluated by the in vitro refolding method. Three peptides were identified as potential cross-species influenza virus (IV) CTL epitopes. The binding motif of SLA-1 0401 was proposed, and thermostabilities of key peptide-SLA-1 0401 complexes were analyzed by circular dichroism spectra. Our results not only provide the structural basis of peptide presentation by SLA I but also identify some IV CTL epitope peptides. These results will benefit both vaccine development and swine organ-based xenotransplantation.

  2. New polycomb group protein enhancer of zeste homolog (EZH) 2-derived peptide with the potential to induce cancer-reactive cytotoxic T lymphocytes in prostate cancer patients with HLA-A3 supertype alleles.

    PubMed

    Minami, Takafumi; Minami, Tomoko; Shimizu, Nobutaka; Yamamoto, Yutaka; De Velasco, Marco A; Nozawa, Masahiro; Yoshimura, Kazuhiro; Harashima, Nanae; Harada, Mamoru; Uemura, Hirotsugu

    2015-05-01

    Analyses on reactivity of anti-cancer cytotoxic T lymphocytes (CTLs) and clinical application of peptide-based anti-cancer vaccine have been mainly focused on patients with HLA-A2 or -A24 alleles. In this study, we identified an enhancer of zeste homolog (EZH) 2-derived peptide applicable for anti-cancer vaccine for prostate cancer patients with HLA-A3 supertype alleles. Five EZH2-derived peptides that were prepared based on the binding motif to the HLA-A3 supertype alleles (HLA-A11, -A31, and -A33) were functionally screened for their potential to induce peptide-specific CTLs from peripheral blood mononuclear cells (PBMCs) of HLA-A3 supertype allele(+) prostate cancer patients. As a result, EZH2733-741 peptide was found to efficiently induce peptide-specific CTLs. The EZH2733-741 peptide-stimulated and purified CD8(+) T cells from PBMCs of HLA-A3 supertype allele(+) prostate cancer patients showed higher cytotoxicity against HLA-A3 supertype allele-expressing LNCaP prostate cancer cells than against parental LNCaP cells. This cytotoxicity against HLA-A3 supertype allele-expressing LNCaP cells was partially but significantly inhibited by the addition of EZH2733-741 peptide-pulsed competitive cells. These results indicate that the EZH2733-741 peptide could be a promising candidate for peptide-based immunotherapy for HLA-A3 supertype allele(+) prostate cancer patients.

  3. Lentiviral vectors encoding human immunodeficiency virus type 1 (HIV-1)-specific T-cell receptor genes efficiently convert peripheral blood CD8 T lymphocytes into cytotoxic T lymphocytes with potent in vitro and in vivo HIV-1-specific inhibitory activity.

    PubMed

    Joseph, Aviva; Zheng, Jian Hua; Follenzi, Antonia; Dilorenzo, Teresa; Sango, Kaori; Hyman, Jaime; Chen, Ken; Piechocka-Trocha, Alicja; Brander, Christian; Hooijberg, Erik; Vignali, Dario A; Walker, Bruce D; Goldstein, Harris

    2008-03-01

    The human immunodeficiency virus type 1 (HIV-1)-specific CD8 cytotoxic T-lymphocyte (CTL) response plays a critical role in controlling HIV-1 replication. Augmenting this response should enhance control of HIV-1 replication and stabilize or improve the clinical course of the disease. Although cytomegalovirus (CMV) or Epstein-Barr virus (EBV) infection in immunocompromised patients can be treated by adoptive transfer of ex vivo-expanded CMV- or EBV-specific CTLs, adoptive transfer of ex vivo-expanded, autologous HIV-1-specific CTLs had minimal effects on HIV-1 replication, likely a consequence of the inherently compromised qualitative function of HIV-1-specific CTLs derived from HIV-1-infected individuals. We hypothesized that this limitation could be circumvented by using as an alternative source of HIV-1-specific CTLs, autologous peripheral CD8(+) T lymphocytes whose antigen specificity is redirected by transduction with lentiviral vectors encoding HIV-1-specific T-cell receptor (TCR) alpha and beta chains, an approach used successfully in cancer therapy. To efficiently convert peripheral CD8 lymphocytes into HIV-1-specific CTLs that potently suppress in vivo HIV-1 replication, we constructed lentiviral vectors encoding the HIV-1-specific TCR alpha and TCR beta chains cloned from a CTL clone specific for an HIV Gag epitope, SL9, as a single transcript linked with a self-cleaving peptide. We demonstrated that transduction with this lentiviral vector efficiently converted primary human CD8 lymphocytes into HIV-1-specific CTLs with potent in vitro and in vivo HIV-1-specific activity. Using lentiviral vectors encoding an HIV-1-specific TCR to transform peripheral CD8 lymphocytes into HIV-1-specific CTLs with defined specificities represents a new immunotherapeutic approach to augment the HIV-1-specific immunity of infected patients.

  4. MAGE-A1, MAGE-A3, and NY-ESO-1 can be upregulated on neuroblastoma cells to facilitate cytotoxic T lymphocyte-mediated tumor cell killing.

    PubMed

    Bao, Lei; Dunham, Kimberly; Lucas, Kenneth

    2011-09-01

    Approximately half of patients with stage IV neuroblastoma are expected to relapse despite current therapy, and when this occurs, there is little likelihood of achieving a cure. Very few clinical trials have been conducted to determine whether cellular immune responses could be harnessed to fight this tumor, largely because potential tumor antigens for cytotoxic T lymphocytes (CTL) are limited. MAGE-A1, MAGE-A3, and NY-ESO-1 are cancer-testis (CT) antigens expressed on a number of malignant solid tumors, including neuroblastoma, but many tumor cell lines down-regulate the expression of CT antigens as well as major histocompatibility (MHC) antigens, precluding recognition by antigen-specific T cells. If expression of cancer antigens on neuroblastoma could be enhanced pharmacologically, CT antigen-specific immunotherapy could be considered for this tumor. We have demonstrated that the expression of MAGE-A1, MAGE-A3, and NY-ESO-1 can be upregulated on neuroblastoma cells following exposure to pharmacologic levels of the demethylating agent 5-aza-2'-deoxycytidine (decitabine, DAC). Expression of NY-ESO-1, MAGE-A1, or MAGE-A3 was induced in 10/10 neuroblastoma cell lines after 5 days of exposure to DAC. Culture of neuroblastoma cell lines with IFN-γ was also associated with an increased expression of either MHC Class I or II by cytofluorometry, as reported by other groups. MAGE-A1, MAGE-A3, and NY-ESO-1-specific CTL were cultured from volunteer donors by stimulating peripheral blood mononuclear cells with dendritic cells pulsed with overlapping peptide mixes derived from full-length proteins, and these CTL preferentially lysed HLA partially matched, DAC-treated neuroblastoma and glioblastoma cell lines. These studies show that demethylating chemotherapy can be combined with IFN-γ to increase the expression of CT antigens and MHC molecules on neuroblastoma cells, and pre-treatment with these agents makes tumor cell lines more susceptible to CTL-mediated killing. These

  5. The human cytotoxic T-lymphocyte (CTL) response to cytomegalovirus is dominated by structural protein pp65: frequency, specificity, and T-cell receptor usage of pp65-specific CTL.

    PubMed Central

    Wills, M R; Carmichael, A J; Mynard, K; Jin, X; Weekes, M P; Plachter, B; Sissons, J G

    1996-01-01

    Cytotoxic T lymphocytes (CTL) appear to play an important role in the control of human cytomegalovirus (HCMV) in the normal virus carrier: previous studies have identified peripheral blood CD8+ CTL specific for the HCMV major immediate-early gene product (IE1) and more recently, by bulk culture and cloning techniques, have identified CTL specific for a structural gene product, the lower matrix protein pp65. In order to determine the relative contributions of CTL which recognize the HCMV proteins IE1, pp65, and glycoprotein B (gB) to the total HCMV-specific CTL response, we have used a limiting-dilution analysis system to quantify HCMV-specific CTL precursors with different specificities, allowing the antigenic specificity of multiple short-term CTL clones to be assessed, in a group of six healthy seropositive donors. All donors showed high frequencies of HCMV-specific major histocompatibility complex-restricted CTL precursors. There was a very high frequency of CTL specific for pp65 (lower matrix protein); IE1-specific CTL were also detectable at lower frequencies in three of five donors, while CTL directed to gB were undetectable. A pp65 gene deletion mutant of HCMV was then used to estimate the contribution of pp65-specific CTL to the total HCMV-specific CTL response; this showed that between 70 and 90% of all CTL recognizing HCMV-infected cells were pp65 specific. Analysis of the peptide specificity of pp65-specific CTL showed that some donors have a highly focused response recognizing a single peptide; the T-cell receptor Vbeta gene usage in these two donors was shown to be remarkably restricted, with over half of the responding CD8+ T cells utilizing a single Vbeta gene rearrangement. Other subjects recognized multiple pp65 peptides: nine new pp65 CTL peptide epitopes were defined, and for five of these the HLA-presenting allele has been identified. All four of the HLA A2 donors tested in this study recognized the same peptide. This apparent domination of the

  6. Current evidence on the cytotoxic T-lymphocyte antigen 4 + 49G > A polymorphism and digestive system cancer risks: a meta-analysis involving 11,923 subjects

    PubMed Central

    Xiaolei, Liu; Baohong, Yang; Haipeng, Ren; Shuzhen, Liu; Jianfeng, Gao; Xiangpo, Pan; Haiyu, Liu; Yuan, Yu; Dejie, Zheng; Jinhong, Yang; Huanxin, Wang; Wenhui, Wang; Guohua, Yu

    2015-01-01

    Cytotoxic T-lymphocyte antigen (CTLA-4) plays an important role in downregulating T cell activation and proliferation. The CTLA-4 + 49G > A polymorphism is one of the most commonly studied polymorphisms in this gene due to its association with many cancer types, but the association between CTLA-4 + 49G > A polymorphism and digestive system cancer risks remain inconclusive. An updated meta-analysis based on 17 independent case–control studies consisting of 5176 cancer patients and 6747 controls was performed to address this association. Overall, there was no statistically increased risk of digestive system cancers in every genetic comparison. In subgroup analysis, this polymorphism was significantly linked to higher risks for pancreatic cancer (GG vs. AA, OR = 1.976, 95% CI = 1.496–2.611; GA vs. AA, OR = 1.433, 95% CI = 1.093–1.879; GG/GA vs. AA, OR = 1.668, 95% CI = 1.286–2.164; GG vs. GA/AA, OR = 1.502, 95% CI = 1.098–2.054; G vs. A, OR = 1.394, 95% CI = 1.098–1.770). We also observed increased susceptibility of hepatocellular cell carcinoma in homozygote comparison (OR = 1.433, 95% CI = 1.100–1.866) and dominant model (OR = 1.360, 95% CI = 1.059–1.746). According to the source of controls, significant effects were only observed in hospital-based studies (GA/AA vs. GG, OR = 1.257, 95% CI = 1.129–1.399). In the stratified analysis by ethnicity, no significantly increased risks were found in either Asian or Caucasian. Our findings suggest that the CTLA-4 + 49G > A polymorphism may be associated with the risk of pancreatic cancer and hepatocellular cell carcinoma. PMID:26629416

  7. Self-assembling peptide for co-delivery of HIV-1 CD8+ T cells epitope and Toll-like receptor 7/8 agonists R848 to induce maturation of monocyte derived dendritic cell and augment polyfunctional cytotoxic T lymphocyte (CTL) response.

    PubMed

    Ding, Yong; Liu, Jun; Lu, Sheng; Igweze, Justice; Xu, Wen; Kuang, Da; Zealey, Chris; Liu, Daheng; Gregor, Alex; Bozorgzad, Ardalan; Zhang, Lei; Yue, Elizabeth; Mujib, Shariq; Ostrowski, Mario; Chen, P

    2016-08-28

    Peptide based vaccine that incorporates one or several highly conserved CD8+ T cells epitopes to induce potent cytotoxic T lymphocyte (CTL) response is desirable for some infectious diseases, such as HIV-1 (human immunodeficiency virus-1), and cancers. However, the CD8+ T cells epitope is often weakly immunogenic, and thus requires a specific adjuvant or delivery system to enhance the efficiency. Here we investigated the use of self-assembling peptide EAK16-II based platform to achieve the co-delivery of CD8+ T cells epitope and TLR7/8 agonists (R848 or R837) for augmenting DCs maturation and HIV-1 specific CTL response. HIV-1 CTL epitope SL9 was conjugated with EAK16-II to obtain SL9-EAK16-II, which further spontaneously co-assembled with R848 or R837 in aqueous solution, forming co-assembled nanofibers. Fluorescence spectra and calorimetrical titration revealed the interaction between SL9-EAK16-II assemblies and R848 or R837 via hydrogen bonding and hydrophobic interaction, with the binding affinity (dissociation constant Kd) of 0.62μM or 0.53μM, respectively. Ex vivo generated DCs from HIV-1+ patients pulsed with the SL9-EAK16-II/R848 nanofibers stimulated significantly more polyfunctional SL9 specific CTLs, compared to the DCs pulsed with SL9 alone or the mixture of SL9 and TLR agonist. Furthermore, the nanofibers elicited stronger SL9 specific CTL response in vaccinated mice. Our findings suggest the self-assembling peptide EAK16-II might be used as a new delivery system for peptide based vaccines. PMID:27297778

  8. Simian Virus 40 Large-T-Antigen-Specific Rejection of mKSA Tumor Cells in BALB/c Mice Is Critically Dependent on both Strictly Tumor-Associated, Tumor-Specific CD8+ Cytotoxic T Lymphocytes and CD4+ T Helper Cells

    PubMed Central

    Utermöhlen, Olaf; Schulze-Garg, Christine; Warnecke, Gabriele; Gugel, Roland; Löhler, Jürgen; Deppert, Wolfgang

    2001-01-01

    Protective immunity of BALB/c mice immunized with simian virus 40 (SV40) large T antigen (TAg) against SV40-transformed, TAg-expressing mKSA tumor cells is critically dependent on both CD8+ and CD4+ T lymphocytes. By depleting mice of T-cell subsets at different times before and after tumor challenge, we found that at all times, CD4+ and CD8+ cells both were equally important in establishing and maintaining a protective immune response. CD4+ cells do not contribute to tumor eradication by directly lysing mKSA cells. However, CD4+ lymphocytes provide help to CD8+ cells to proliferate and to mature into fully active cytotoxic T lymphocytes (CTL). Depletion of CD4+ cells by a single injection of CD4-specific monoclonal antibody at any time from directly before injection of the vaccinating antigen to up to 7 days after tumor challenge inhibited the generation of cytolytic CD8+ lymphocytes. T helper cells in this system secrete the typical Th-1 cytokines interleukin 2 (IL-2) and gamma interferon. Because in this system TAg-specific CD8+ cells secrete only minute amounts of IL-2, it appears that T helper cells provide these cytokines for CD8+ T cells. Moreover, this helper effect of CD4+ T cells in mKSA tumor rejection in BALB/c mice does not simply improve the activity of TAg-specific CD8+ CTL but actually enables them to mature into cytolytic effector cells. Beyond this activity, the presence of T helper cells is necessary even in the late phase of tumor cell rejection in order to maintain protective immunity. However, despite the support of CD4+ T helper cells, the tumor-specific CTL response is so weak that only at the site of tumor cell inoculation and not in the spleen or in the regional lymph nodes can TAg-specific CTL be detected. PMID:11602701

  9. The Relationship between Memory and Inductive Reasoning: Does It Develop?

    ERIC Educational Resources Information Center

    Hayes, Brett K.; Fritz, Kristina; Heit, Evan

    2013-01-01

    In 2 studies, the authors examined the development of the relationship between inductive reasoning and visual recognition memory. In both studies, 5- to 6-year-old children and adults were shown instances of a basic-level category (dogs) followed by a test set containing old and new category members that varied in their similarity to study items.…

  10. Human Epstein-Barr virus (EBV)-specific cytotoxic T lymphocytes home preferentially to and induce selective regressions of autologous EBV- induced B cell lymphoproliferations in xenografted C.B-17 scid/scid mice [published erratum appears in J Exp Med 1996 Sep 1;184(3):1199

    PubMed Central

    1996-01-01

    C.B-17 scid/scid (severe combined immunodeficiency [SCID]) mice inoculated with peripheral blood lymphocytes from Epstein-Barr virus (EBV)-seropositive donors, or with EBV-transformed lymphoblastoid B cell lines (EBV-LCL), develop lethal human EBV+ B cell lymphoproliferative disorders (EBV-LPD) with characteristics similar to those arising in immunodeficient patients. Using this model, we examined the capacity of human effector cells to control human EBV-LPD. SCID mice received rabbit anti-asialo GM1 antiserum to abrogate endogenous natural killer-cell function. Preliminary experiments showed that adoptive transfer of peripheral blood mononuclear cells (PBMC), purified T cells, interleukin (IL) 2-activated PBMC or anti-CD3- activated T cells derived from EBV-seropositive donors did not result in improved survival of treated mice (in vivo effector/target ratio 2:1 to 1:1). In contrast, EBV-specific cytotoxic T lymphocytes (CTL), derived from EBV-seropositive donors and expanded in vitro, exhibited strong EBV-specific and HLA-restricted activity both in vitro and in vivo. SCID mice inoculated intraperitoneally with autologous but not with HLA-mismatched EBV-LCL had significantly improved survival relative to untreated mice after inoculation of EBV-specific CTL either intraperitoneally (P<0.001) or intravenously (P<0.001) (in vivo effector/target ratio 1:1). SCID mice bearing large subcutaneous EBV+ tumors and treated intravenously with 10(7) EBV-specific CTL achieved complete tumor regression. Both CTL- and CTL-plus-IL-2-treated mice survived significantly longer than untreated animals or animals treated with IL-2 alone (P = 0.0004 and P<0.02, respectively). SCID mice bearing two subcutaneous EBV+ tumors, one autologous and the other HLA mismatched to the EBV-specific CTL donor, had regression of only the autologous tumor after intravenous infusion of 10(7) EBV-specific CTL. Moreover, we could demonstrate preferential homing of PKH26-labeled EBV- specific CTL to

  11. T cell receptor (TCR) structure of autologous melanoma-reactive cytotoxic T lymphocyte (CTL) clones: tumor-infiltrating lymphocytes overexpress in vivo the TCR beta chain sequence used by an HLA-A2- restricted and melanocyte-lineage-specific CTL clone

    PubMed Central

    1993-01-01

    HLA-A2+ melanomas express common melanoma-associated antigens (Ags) recognized in vitro by autologous cytotoxic T lymphocytes (CTL). However, it is not known whether tumor Ags can drive in vivo a selective accumulation/expansion of Ag-specific, tumor-infiltrating T lymphocytes (TIL). Therefore, to evaluate this possibility, 39 CTL clones isolated from several independent mixed lymphocyte tumor cultures (MLTC) of TIL and peripheral blood lymphocytes (PBL) of an HLA- A2+ melanoma patient and selected for T cell receptor (TCR)-dependent, HLA-restricted tumor lysis, were used for analysis of TCR alpha and beta chain structure by the cDNA polymerase chain reaction (PCR) technique with variable gene-specific primers followed by sequencing. Despite absence of oligoclonality in fresh TIL and PBL, as well as in T cells of day 28 MLTC (day of cloning), sequence analysis of TCR alpha and beta chains of TIL clones revealed a dominance of a major category of melanoma-specific, HLA-A2-restricted T cells expressing a V alpha 8.2/J alpha AP511/C alpha and V beta 2.1/D beta 1/J beta 1.1/C beta 1 TCR. The same TCR was also found in 2 out of 14 PBL clones. The other PBL clones employed a V alpha 2.1 gene segment associated with either V beta 13.2, 14, or w22. Clones A81 (V alpha 2.1/J alpha IGRJ alpha 04/C alpha and V beta 14/D beta 1/J beta 1.2/C beta 1) and A21 (V alpha 8.2/J alpha AP511/C alpha and V beta 2.1/D beta 1/J beta 1.1/C beta 1), representative of the two most frequent TCR of PBL and TIL, respectively, expressed different lytic patterns, but both were HLA-A2 restricted and lysed only HLA-A2+ melanomas and normal melanocytes, thus indicating recognition of two distinct HLA-A2-associated and tissue-related Ags. Finally, by the inverse PCR technique, the specific TCR beta chain (V beta 2.1/D beta 1/J beta 1.1/C beta 1) expressed by the dominant TIL clone was found to represent 19 and 18.4% of all V beta 2 sequences expressed in the fresh tumor sample and in the purified TIL

  12. A Toll-like receptor 2 agonist-fused antigen enhanced antitumor immunity by increasing antigen presentation and the CD8 memory T cells population

    PubMed Central

    Wu, Chiao-Chieh; Liu, Shih-Jen; Chen, Hsin-Wei; Shen, Kuan-Yin; Leng, Chih-Hsiang

    2016-01-01

    The induction of long-lived effector CD8+ T cells is key to the development of efficient cancer vaccines. In this study, we demonstrated that a Toll-like receptor 2 (TLR2) agonist-fused antigen increased antigen presentation via TLR2 signaling and induced effector memory-like CD8+ T cells against cancer after immunization. The N-terminus of ovalbumin (OVA) was biologically fused with a bacterial lipid moiety TLR2 agonist to produce a recombinant lipidated ovalbumin (rlipo-OVA). We demonstrated that rlipo-OVA activated bone marrow-derived dendritic cells (BM-DCs) maturation and increased antigen presentation by major histocompatibility complex (MHC) class I via TLR2. After immunization, rlipo-OVA skewed the immune response towards T helper (Th) 1 and induced OVA-specific cytotoxic T lymphocyte (CTL) responses. Moreover, immunization with rlipo-OVA induced higher numbers of effector memory (CD44+CD62L−) CD8+ T cells compared with recombinant ovalbumin (rOVA) alone or rOVA mixed with the TLR2 agonist Pam3CSK4. Accordingly, the CD27+CD43+ effector memory CD8+ T cells expressed high levels of the long-lived CD127 marker. The administration of rlipo-OVA could inhibit tumor growth, but the anti-tumor effects were lost after the depletion of CD8 or CD127 cells in vivo. These findings suggested that the TLR2 agonist-fused antigen induced long-lived memory CD8+ T cells for efficient cancer therapy. PMID:27127171

  13. Creativity and Memory: Effects of an Episodic-Specificity Induction on Divergent Thinking.

    PubMed

    Madore, Kevin P; Addis, Donna Rose; Schacter, Daniel L

    2015-09-01

    People produce more episodic details when imagining future events and solving means-end problems after receiving an episodic-specificity induction-brief training in recollecting details of a recent event-than after receiving a control induction not focused on episodic retrieval. Here we show for the first time that an episodic-specificity induction also enhances divergent creative thinking. In Experiment 1, participants exhibited a selective boost on a divergent-thinking task (generating unusual uses of common objects) after a specificity induction compared with a control induction; by contrast, performance following the two inductions was similar on an object association task thought to involve little divergent thinking. In Experiment 2, we replicated the specificity-induction effect on divergent thinking using a different control induction, and also found that participants performed similarly on a convergent-thinking task following the two inductions. These experiments provide novel evidence that episodic memory is involved in divergent creative thinking.

  14. Induction of WT1-specific human CD8+ T cells from human HSCs in HLA class I Tg NOD/SCID/IL2rgKO mice.

    PubMed

    Najima, Yuho; Tomizawa-Murasawa, Mariko; Saito, Yoriko; Watanabe, Takashi; Ono, Rintaro; Ochi, Toshiki; Suzuki, Nahoko; Fujiwara, Hiroshi; Ohara, Osamu; Shultz, Leonard D; Yasukawa, Masaki; Ishikawa, Fumihiko

    2016-02-11

    Induction of specific immune response against therapy-resistant tumor cells can potentially improve clinical outcomes in malignancies. To optimize immunotherapy in the clinic, we aimed to create an in vivo model enabling us to analyze human cytotoxic T-lymphocyte (CTL) responses against human malignancies. To this end, we developed NOD/SCID/IL2rgKO (NSG) mice expressing the HLA class I molecules HLA-A*0201 and A*2402. In the bone marrow (BM) and spleen of HLA class I transgenic (Tg) NSG mice transplanted with cord blood hematopoietic stem cells (HSCs), we found human memory CD8(+) T cells and antigen-presenting cells. To evaluate antigen-specific human CTL responses, we immunized HLA class I Tg NSG mice using polyinosinic:polycytidylic acid mixed Wilms tumor 1 (WT1) peptides, with or without WT1 peptide-loaded autologous dendritic cells. After immunization, the frequencies of HLA-restricted WT1-specific CTLs increased significantly in the spleen. Next, we transplanted the WT1-specific T-cell receptor (WT1-TCR) gene-transduced human HSCs into HLA class I Tg NSG newborn mice. WT1 tetramer-positive CD8(+) T cells differentiated from WT1-TCR-transduced HSCs in the recipients' BM, spleen, and thymus. Upon stimulation with WT1 peptide in vitro, these CTLs produced interferon-γ and showed lytic activity against leukemia cells in an antigen-specific, HLA-restricted manner. HLA class I Tg NSG xenografts may serve as a preclinical model to develop effective immunotherapy against human malignancies.

  15. Induction of WT1-specific human CD8+ T cells from human HSCs in HLA class I Tg NOD/SCID/IL2rgKO mice.

    PubMed

    Najima, Yuho; Tomizawa-Murasawa, Mariko; Saito, Yoriko; Watanabe, Takashi; Ono, Rintaro; Ochi, Toshiki; Suzuki, Nahoko; Fujiwara, Hiroshi; Ohara, Osamu; Shultz, Leonard D; Yasukawa, Masaki; Ishikawa, Fumihiko

    2016-02-11

    Induction of specific immune response against therapy-resistant tumor cells can potentially improve clinical outcomes in malignancies. To optimize immunotherapy in the clinic, we aimed to create an in vivo model enabling us to analyze human cytotoxic T-lymphocyte (CTL) responses against human malignancies. To this end, we developed NOD/SCID/IL2rgKO (NSG) mice expressing the HLA class I molecules HLA-A*0201 and A*2402. In the bone marrow (BM) and spleen of HLA class I transgenic (Tg) NSG mice transplanted with cord blood hematopoietic stem cells (HSCs), we found human memory CD8(+) T cells and antigen-presenting cells. To evaluate antigen-specific human CTL responses, we immunized HLA class I Tg NSG mice using polyinosinic:polycytidylic acid mixed Wilms tumor 1 (WT1) peptides, with or without WT1 peptide-loaded autologous dendritic cells. After immunization, the frequencies of HLA-restricted WT1-specific CTLs increased significantly in the spleen. Next, we transplanted the WT1-specific T-cell receptor (WT1-TCR) gene-transduced human HSCs into HLA class I Tg NSG newborn mice. WT1 tetramer-positive CD8(+) T cells differentiated from WT1-TCR-transduced HSCs in the recipients' BM, spleen, and thymus. Upon stimulation with WT1 peptide in vitro, these CTLs produced interferon-γ and showed lytic activity against leukemia cells in an antigen-specific, HLA-restricted manner. HLA class I Tg NSG xenografts may serve as a preclinical model to develop effective immunotherapy against human malignancies. PMID:26702062

  16. Creativity and Memory: Effects of an Episodic Specificity Induction on Divergent Thinking

    PubMed Central

    Madore, Kevin P.; Addis, Donna Rose; Schacter, Daniel L.

    2015-01-01

    After receiving an episodic specificity induction - brief training in recollecting details of a recent event - people produce more episodic details when imagining future events and solving means-end problems than after receiving a control induction not focused on episodic retrieval. Here we show for the first time that an episodic specificity induction also enhances divergent creative thinking. In Experiment 1, participants exhibited a selective boost on a divergent thinking task that involves generating unusual uses of common objects after a specificity induction compared with a control induction; by contrast, performance was similar on an object association task thought to involve little divergent thinking. In Experiment 2, we replicated the specificity induction effect on divergent thinking using a different control induction, and also found that participants performed similarly on a convergent thinking task following both inductions. These experiments provide novel evidence that episodic memory is involved in divergent creative thinking. PMID:26205963

  17. Induction of IgG memory responses with polyvinylpyrrolidone (PVP) is antigen dose dependent

    SciTech Connect

    Lite, H.S.; Braley-Mullen, H.

    1981-03-01

    Irradiated recipients of spleen cells from mice primed with a very low dose (0.0025 ..mu../g) of the thymus-independent (TI) antigen polyvinylpyrrolidone (PVP) produced PVP-specific IgG memory responses after secondary challenge with a T-dependent (TD) form of PVP, PVP-HRBC. The IgG memory responses induced by low doses of PVP were similar in magnitude to those induced by the TD antigen PVP-HRBC. The induction of IgG memory by the TI form of antigen was markedly dependent on the dose of PVP used to prime donor mice. Spleen cells from mice primed with an amount of PVP (0.25 ..mu..g) that induces an optimal primary IgM response did not produce significant IgG antibody after challenge with PVP-HRBC. The inability of higher doses of PVP to induce IgG memory may be due, at least in part, to the fact that such doses of PVP were found to induce tolerance in PVP-specific B cells and could suppress the induction of memory induced by PVP-HRBC. Low doses of PVP did not interfere with the induction of memory by PVP-HRBC. Expression of IgG memory responses in recipients of PVP-HRBC or low-dose PVP-primed cells was found to be T cell dependent. Moreover, only primed T cells could reconstitute the respnse of recipients of primed B cells, suggesting that the ability of PVP to induce IgG memory may be related to its ability to prime T helper cells. Expression of the IgG memory response in recipient mice also required the use of a TD antigen for secondary challenge, i.e., mice challenged with PVP did not develop IgG.

  18. The Velten Mood Induction Procedure: Effects on Mood and Memory.

    ERIC Educational Resources Information Center

    Riskind, John H.; And Others

    1982-01-01

    Examined the hypothesis that the self-devaluative aspects of the Velton Mood Induction Procedure (VMIP) do not lower mood but that the depression-related somatic states of the VMIP do lower mood. Found that both aspects of the VMIP have a powerful impact on mood. (Author/RC)

  19. INFLUENCE OF EXPOSURE HISTORY ON VITELLOGENIN INDUCTION IN MEDAKA: A CASE OF "ESTROGEN MEMORY"?

    EPA Science Inventory

    Influence of Exposure History on Vitellogenin Induction in Medaka: a Case of "Estrogen Memory"? (Abstract). Mar. Environ. Res. 50(1-5):196.

    In this study, we exposed female medaka to aqueous solutions of o,p'-DDT until tissues residues reached approximately 100 g/g. Male...

  20. Depressive symptoms moderate the effects of a self-discrepancy induction on overgeneral autobiographical memory.

    PubMed

    Smets, Jorien; Griffith, James W; Wessel, Ineke; Walschaerts, Dominique; Raes, Filip

    2013-01-01

    According to the CaRFAX model, rumination is one of the key underlying mechanisms of overgeneral autobiographical memory (OGM). The association between rumination and OGM is well established in clinical populations, but this relationship is not robust in nonclinical samples. A series of null findings is reported in the current paper. Additionally we followed up on recent findings suggesting that a state of rumination needs to be active in order to detect a relationship between trait-rumination and OGM. Secondary school students (N= 123) completed questionnaires assessing trait-rumination and depressive symptoms as well as two autobiographical memory tests (AMTs), one before and one after a self-discrepancy induction. This induction should trigger state-rumination, which would subsequently promote the retrieval of general rather than specific memories. Trait-rumination failed to predict increases in OGM. We did find, however, that higher BDI-II scores were positively related to an increase in OGM following the induction. This adds to the growing body of evidence that OGM reactivity might be more important than baseline memory specificity.

  1. Role of lipopolysaccharide in the induction of type I interferon-dependent cross-priming and IL-10 production in mice by meningococcal outer membrane vesicles.

    PubMed

    Durand, Vanessa; Mackenzie, Joanne; de Leon, Joel; Mesa, Circe; Quesniaux, Valérie; Montoya, Maria; Le Bon, Agnes; Wong, Simon Y C

    2009-03-18

    We investigated the contribution of lipopolysaccharide (LPS) to adjuvant properties of native outer membrane vesicles (NOMV), a vaccine candidate for meningococcal B disease. NOMV induce the maturation of and cytokine production by murine bone marrow-derived dendritic cells through both toll-like receptors (TLR) 2 and 4 which are mostly dependent on the signalling adaptor MyD88. NOMV are also able to induce B cell proliferation in splenocytes from LPS-hyporesponsive mice. However, induction of IL-10 and type I interferon-dependent, antigen-specific and IFN(gamma)-secreting CD8(+) cytotoxic T lymphocyte responses in vivo by NOMV requires LPS. The importance of LPS in the induction of IL-10 and functional cross-priming has implications for NOMV-based vaccine and adjuvant development. PMID:19368771

  2. Association of Neisseria gonorrhoeae Opa(CEA) with dendritic cells suppresses their ability to elicit an HIV-1-specific T cell memory response.

    PubMed

    Yu, Qigui; Chow, Edith M C; McCaw, Shannon E; Hu, Ningjie; Byrd, Daniel; Amet, Tohti; Hu, Sishun; Ostrowski, Mario A; Gray-Owen, Scott D

    2013-01-01

    Infection with Neisseria gonorrhoeae (N. gonorrhoeae) can trigger an intense local inflammatory response at the site of infection, yet there is little specific immune response or development of immune memory. Gonococcal surface epitopes are known to undergo antigenic variation; however, this is unlikely to explain the weak immune response to infection since individuals can be re-infected by the same serotype. Previous studies have demonstrated that the colony opacity-associated (Opa) proteins on the N. gonorrhoeae surface can bind human carcinoembryonic antigen-related cellular adhesion molecule 1 (CEACAM1) on CD4⁺ T cells to suppress T cell activation and proliferation. Interesting in this regard, N. gonorrhoeae infection is associated with impaired HIV-1 (human immunodeficiency virus type 1)-specific cytotoxic T-lymphocyte (CTL) responses and with transient increases in plasma viremia in HIV-1-infected patients, suggesting that N. gonorrhoeae may also subvert immune responses to co-pathogens. Since dendritic cells (DCs) are professional antigen presenting cells (APCs) that play a key role in the induction of an adaptive immune response, we investigated the effects of N. gonorrhoeae Opa proteins on human DC activation and function. While morphological changes reminiscent of DC maturation were evident upon N. gonorrhoeae infection, we observed a marked downregulation of DC maturation marker CD83 when the gonococci expressing CEACAM1-specific Opa(CEA), but not other Opa variants. Consistent with a gonococcal-induced defect in maturation, Opa(CEA) binding to CEACAM1 reduced the DCs' capacity to stimulate an allogeneic T cell proliferative response. Moreover, Opa(CEA)-expressing N. gonorrhoeae showed the potential to impair DC-dependent development of specific adaptive immunity, since infection with Opa(CEA)-positive gonococci suppressed the ability of DCs to stimulate HIV-1-specific memory CTL responses. These results reveal a novel mechanism to explain why

  3. Electromagnetic induction heating of an orthopaedic nickel--titanium shape memory device.

    PubMed

    Müller, Christian W; Pfeifer, Ronny; El-Kashef, Tarek; Hurschler, Christof; Herzog, Dirk; Oszwald, Markus; Haasper, Carl; Krettek, Christian; Gösling, Thomas

    2010-12-01

    Shape memory orthopaedic implants made from nickel-titanium (NiTi) might allow the modulation of fracture healing, changing their cross-sectional shape by employing the shape memory effect. We aimed to show the feasibility and safety of contact-free electromagnetic induction heating of NiTi implants in a rat model. A water-cooled generator-oscillator combination was used. Induction characteristics were determined by measuring the temperature increase of a test sample in correlation to generator power and time. In 53 rats, NiTi implants were introduced into the right hind leg. The animals were transferred to the inductor, and the implant was electromagnetically heated to temperatures between 40 and 60°C. Blood samples were drawn before and 4 h after the procedure. IL-1, IL-4, IL-10, TNF-α, and IFN-γ were measured. Animals were euthanized at 3 weeks. Histological specimens from the hind leg and liver were retrieved and examined for inflammatory changes, necrosis, and corrosion pits. Cytokine measurements and histological specimens showed no significant differences among the groups. We concluded that electromagnetic induction heating of orthopedic NiTi implants is feasible and safe in a rat model. This is the first step in the development of new orthopedic implants in which stiffness or rigidity can be modified after implantation to optimize bone-healing.

  4. Human gamma interferon production by cytotoxic T lymphocytes sensitized during hepatitis A virus infection

    SciTech Connect

    Maier, K.; Gabriel, P.; Koscielniak, E.; Stierhof, Y.D.; Wiedmann, K.H.; Flehmig, B.; Vallbracht, A.

    1988-10-01

    The production of interferon (IFN) during a chromium-51 release assay with hepatitis A virus (HAV)-infected fibroblasts and autologous peripheral blood lymphocytes from patients with acute HAV infection was studied to determine whether IFN plays a role in immunopathogenesis of hepatitis A infection in humans. Skin fibroblasts of eight patients after acute HAV infection and from two control persons without history of current of past HAV infection were infected with HAV. Peripheral blood lymphocytes were collected at different times after the onset of icterus and tested in a chromium-51 release assay against autologous HAV-infected skin fibroblasts for their cytolytic and IFN-producing activity. The IFN produced during the assay was characterized and found to have the properties of human gamma IFN. Cytotoxicity and gamma IFN release were virus specific. The cell types responsible for both functions were characterized and found to be in the HLA-dependent T8/sup +/ lymphocyte subset. Considering that gamma IFN has an antiviral effect on persistent HAV infection in vitro and that it probably accounts for stimulation of HLA class I antigen expression on hepatocytes, these experimental results presented here demonstrate that human gamma IFN produced by HAV-specific T cells may participate in pathogenesis of hepatitis A infection in humans.

  5. Immune recognition of AIDS virus antigens by human and murine cytotoxic T lymphocytes.

    PubMed

    Langlade-Demoyen, P; Michel, F; Hoffenbach, A; Vilmer, E; Dadaglio, G; Garicia-Pons, F; Mayaud, C; Autran, B; Wain-Hobson, S; Plata, F

    1988-09-15

    The CTL response to HIV was analyzed in humans and in mice. By using a novel and strictly autologous lymphocyte culture system, human CTL lines were established with PBL from seropositive asymptomatic donors and from patients suffering from AIDS or presenting AIDS-related complex. CTL from HLA-A2 donors recognize and kill murine P815 mastocytoma cells doubly transfected with the human HLA-A2 gene and the HIV env gene; they also kill HLA-compatible human macrophages infected with HIV. CTL specific for the HIV env Ag were also generated in BALB/c mice by immunization with syngeneic murine cells transfected with the HIV env gene. Human and murine HIV-immune CTL populations belong to the CD8 subset of T lymphocytes and are restricted by class I HLA or H-2 transplantation Ag, respectively, in the recognition of HIV env Ag. The two different experimental systems presented here can be used to study CD8 lymphocyte immunity against HIV. The murine model of CTL immunity offers the additional advantage of avoiding the manipulation of infectious virus isolates.

  6. Unusually high frequencies of HIV-specific cytotoxic T lymphocytes in humans.

    PubMed

    Hoffenbach, A; Langlade-Demoyen, P; Dadaglio, G; Vilmer, E; Michel, F; Mayaud, C; Autran, B; Plata, F

    1989-01-15

    CTL specific for the HIV belong to the CD8 subset of T lymphocytes, and their activity is restricted by class I HLA transplantation Ag. In this report, HIV-specific CTL and their precursor cells were quantified by limiting dilution analysis. CTL were recovered from the lungs, lymph nodes, and blood of asymptomatic seropositive carriers and of patients with AIDS. HIV was found to be very immunogenic. High frequencies of both HIV-specific CTL and CTL precursor cells were detected in infected individuals. These CTL killed autologous HIV-infected macrophages and T4 lymphoblasts. They also killed doubly transfected P815-A2-env-LAV mouse tumor cells, which express the human HLA-A2 gene and the HIV-1 env gene. In the longitudinal studies of two HIV-infected patients, CTL and CTL precursor cell frequencies decreased as the clinical and immunologic status of the patients deteriorated. Most surprisingly, PBL from seronegative donors also responded to HIV stimulation in vitro and generated large numbers of HLA-restricted, HIV-specific CTL.

  7. In vivo administration of histoincompatible lymphocytes leads to rapid functional deletion of cytotoxic T lymphocyte precursors

    PubMed Central

    1989-01-01

    It is well established that a single intravenous injection of F1 lymphocytes can rapidly and specifically reduce the ability of a parental recipient to generate CTL against donor alloantigens in a subsequent MLR. By fluorescently labeling the injected cells, we have been able to identify, and if desired, remove them in cell suspensions prepared from recipient spleen and lymph node. The injected cells, whether F1 or syngeneic, appeared to form part of the normal recirculating pool. Removal of injected F1 cells from responder lymph node or spleen cell suspensions had no effect on the response reduction observed in the 5-d in vitro MLR (typically 80% reduction for responder cells taken 2 d after injection of F1 cells). When the frequency of CTL precursors (CTLp) was measured by limiting dilution, it was reduced to the same degree as the MLR response, implying that response reduction is due to a reduction in the number of activatable CTL in the responder cell suspension. An equal mixture of responder cells from treated (i.e., F1 injected) and control mice gave a measured CTLp frequency equivalent to the average of the separate frequencies, implying the absence of suppressor cells active in vitro. Labeled F1 cells recovered from a first recipient could be used to induce response reduction in a second recipient. The results are discussed in terms of APCs that functionally delete rather than stimulate CTLp that recognize them (i.e., a "veto mechanism"). These experiments appear to rule out a role for in vivo-induced suppressor cells up to 8 d after injection of semiallogeneic cells but do not address the question of whether they are induced at later times. PMID:2527945

  8. Positive selection of cytotoxic T lymphocyte escape variants during acute hepatitis C virus infection.

    PubMed

    Guglietta, Silvia; Garbuglia, Anna Rosa; Pacciani, Valentina; Scottà, Cristiano; Perrone, Maria Paola; Laurenti, Luca; Spada, Enea; Mele, Alfonso; Capobianchi, Maria Rosaria; Taliani, Gloria; Folgori, Antonella; Vitelli, Alessandra; Ruggeri, Lionello; Nicosia, Alfredo; Piccolella, Enza; Del Porto, Paola

    2005-09-01

    Cellular immune responses are induced during hepatitis C virus (HCV) infection and acute-phase CD8+ T cells are supposed to play an important role in controlling viral replication. In chimpanzees, failure of CD8+ T cells to control HCV replication has been associated with acquisition of mutations in MHC class I-restricted epitopes. In humans, although selection of escape mutations in an immunodominant CTL epitope has been recently described, the overall impact of immune escape during acute HCV infection is unclear. Here, by performing an in depth analysis of the relationship between early cellular immune responses and viral evolution in a chronically evolving HCV acutely infected individual, we demonstrate: (i) the presence of a potent and focused CD8(+ T cell response against a novel epitope in the NS3 protein, (ii) the elimination of the quasi-species harboring the original amino acid sequence within this epitope, and (iii) the selection for a virus population bearing amino acid changes at a single residue within the cytotoxic T cell epitope that strongly diminished T cell recognition. These results support the view that acute-phase CD8+ T cell responses exert a biologically relevant pressure on HCV replication and that viruses escaping this host response could have a significant survival advantage. PMID:16114108

  9. A Well-Controlled Experimental System to Study Interactions of Cytotoxic T Lymphocytes with Tumor Cells

    PubMed Central

    Neubert, Natalie J.; Soneson, Charlotte; Barras, David; Baumgaertner, Petra; Rimoldi, Donata; Delorenzi, Mauro; Fuertes Marraco, Silvia A.; Speiser, Daniel E.

    2016-01-01

    While T cell-based immunotherapies are steadily improving, there are still many patients who progress, despite T cell-infiltrated tumors. Emerging evidence suggests that T cells themselves may provoke immune escape of cancer cells. Here, we describe a well-controlled co-culture system for studying the dynamic T cell – cancer cell interplay, using human melanoma as a model. We explain starting material, controls, and culture parameters to establish reproducible and comparable cultures with highly heterogeneous tumor cells. Low passage melanoma cell lines and melanoma-specific CD8+ T cell clones generated from patient blood were cultured together for up to 3 days. Living melanoma cells were isolated from the co-culture system by fluorescence-activated cell sorting. We demonstrate that the characterization of isolated melanoma cells is feasible using flow cytometry for protein expression analysis as well as an Agilent whole human genome microarray and the NanoString technology for differential gene expression analysis. In addition, we identify five genes (ALG12, GUSB, RPLP0, KRBA2, and ADAT2) that are stably expressed in melanoma cells independent of the presence of T cells or the T cell-derived cytokines IFNγ and TNFα. These genes are essential for correct normalization of gene expression data by NanoString. Further to the characterization of melanoma cells after exposure to CTLs, this experimental system might be suitable to answer a series of questions, including how the affinity of CTLs for their target antigen influences the melanoma cell response and whether CTL-induced gene expression changes in melanoma cells are reversible. Taken together, our human T cell – melanoma cell culture system is well suited to characterize immune-related mechanisms in cancer cells. PMID:27625650

  10. Autologous tumor-specific cytotoxic T-lymphocytes in a child with neuroblastoma.

    PubMed

    Azuma, E; Hanada, M; Masuda, S I; Komada, Y; Sakurai, M

    1990-01-01

    Activation of peripheral blood lymphocytes from a neuroblastoma patient by co-cultivation with autologous neuroblastoma cells in a mixed lymphocyte-tumor cell culture (A-MLTC) resulted in the generation of cytotoxic activity against the autologous neuroblastoma cell line HNB-MS. A-MLTC was set up in the presence of recombinant human interleukin-2 (IL-2). HNB-MS stimulator was treated with recombinant human interferon-gamma (IFN-gamma) prior to A-MLTC. CTL generated in short-term culture effectively lysed HNB-MS, while they had no effect on an Epstein-Barr virus transformed autologous B-cell line EB-MS. Moreover, CTL lysed 3 different allogeneic neuroblastoma cell lines, but not a rhabdomyosarcoma cell line RBB. Recombinant human tumor necrosis factor-alpha (TNF-alpha) and interleukin-4 (IL-4) enhanced and suppressed CTL generation, respectively, when added to the A-MLTC from the beginning of culture. CD3+ CD4- CD8+ T cells were the major anti-tumor effectors. Furthermore, 111indium-labeled CTL clearly accumulated in metastatic sites. These results indicate that CTL can be used for adoptive immunotherapy in neuroblastoma.

  11. Lysis of MYCN-amplified neuroblastoma cells by MYCN peptide-specific cytotoxic T lymphocytes.

    PubMed

    Sarkar, A K; Nuchtern, J G

    2000-04-01

    The effectiveness of cell-mediated immunotherapy for cancer can be limited by loss-of-antigen mutations that occur during tumor growth. In neuroblastoma, amplification of the MYCN oncogene correlates with rapid tumor progression and a poor prognosis overall. We propose that the MYCN protein, the high-level expression of which is required for maintenance of the malignant phenotype, would be an ideal target for vaccine therapy. The MYCN-derived S9K peptide (amino acids 7-15; STMPGMICK), which contains an HLA-A1 binding motif, was used to generate CTLs from the peripheral blood lymphocytes of an HLA-A1+ healthy donor and an HLA-A1+ patient with MYCN-amplified neuroblastoma These CTL lines specifically lysed HLA-matched, MYCN-amplified neuroblastoma tumor cells. They did not lyse either HLA-mismatched, MYCN-amplified, or matched/nonmatched, non-MYCN-amplified tumor cells. The CTL activity was inhibited by a monoclonal antibody to a class I HLA monomorphic determinant but not by one specific for HLA class II, consistent with a class I-restricted mechanism of cytotoxicity. Antibodies to CD8, but not those to CD4, also inhibited CTL activity, identifying CD8+ lymphocytes as the effector cell population. These results show that MYCN-derived peptides can serve as tumor-specific antigens and suggest a rational approach to cell-mediated immunotherapy for MYCN-amplified neuroblastoma.

  12. A Well-Controlled Experimental System to Study Interactions of Cytotoxic T Lymphocytes with Tumor Cells.

    PubMed

    Neubert, Natalie J; Soneson, Charlotte; Barras, David; Baumgaertner, Petra; Rimoldi, Donata; Delorenzi, Mauro; Fuertes Marraco, Silvia A; Speiser, Daniel E

    2016-01-01

    While T cell-based immunotherapies are steadily improving, there are still many patients who progress, despite T cell-infiltrated tumors. Emerging evidence suggests that T cells themselves may provoke immune escape of cancer cells. Here, we describe a well-controlled co-culture system for studying the dynamic T cell - cancer cell interplay, using human melanoma as a model. We explain starting material, controls, and culture parameters to establish reproducible and comparable cultures with highly heterogeneous tumor cells. Low passage melanoma cell lines and melanoma-specific CD8+ T cell clones generated from patient blood were cultured together for up to 3 days. Living melanoma cells were isolated from the co-culture system by fluorescence-activated cell sorting. We demonstrate that the characterization of isolated melanoma cells is feasible using flow cytometry for protein expression analysis as well as an Agilent whole human genome microarray and the NanoString technology for differential gene expression analysis. In addition, we identify five genes (ALG12, GUSB, RPLP0, KRBA2, and ADAT2) that are stably expressed in melanoma cells independent of the presence of T cells or the T cell-derived cytokines IFNγ and TNFα. These genes are essential for correct normalization of gene expression data by NanoString. Further to the characterization of melanoma cells after exposure to CTLs, this experimental system might be suitable to answer a series of questions, including how the affinity of CTLs for their target antigen influences the melanoma cell response and whether CTL-induced gene expression changes in melanoma cells are reversible. Taken together, our human T cell - melanoma cell culture system is well suited to characterize immune-related mechanisms in cancer cells. PMID:27625650

  13. Effects of adenosine derivatives on cytotoxic T lymphocyte (CTL) and primary antibody responses in mice

    SciTech Connect

    Kandil, O.; Nakic, M.; Nelson, J.A.

    1986-03-05

    Accumulation of adenosine (Ado) and/or deoxyadenosine (dAdo) in adenosine deaminase deficiency is thought to mediate the immunodeficiency associated with the genetic disease in humans. To study the mechanism by which immune function is impaired, we are using analogs which are not substrates for the deaminase. The analogs and their doses (mg/kg/day, IP) are: an Ado analog, Tubercidin (2); and two dAdo analogs, 2-chlorodeoxy-adenosine (50) and 2-fluoro, arabinosyl AMP (250). CTL were generated by injecting C57B1/6 mice with 2.5 x 10/sup 7/ P815 mastocytoma cells, IP. Groups of mice were then treated once daily on days 9-11 with the analogs. On day 12, the animals were sacrificed and spleen cell suspensions were enriched for CTL by passage through nylon wool columns. CTL were measured against /sup 51/Cr-labeled P815 targets using a standard /sup 51/Cr-release assay. Primary antibody response was assessed in AKR mice following immunization with a T-dependent (sheep erythrocytes) or T-independent (TNP-Ficoll) antigen. Animals were treated with the analogs on days 1-3. On day 4, spleen cells were removed and assayed for antibody response in a plaque-forming assay. The dAdo analogs, but not tubercidin, inhibited the immune functions at these near-maximally tolerated doses. Treatment of the mice with the deaminase inhibitor, deoxycoformycin (1 mg/kg/day), was not inhibitory to these responses.

  14. Cytotoxic T lymphocytes recognize and lyse chondrocytes under inflammatory, but not non-inflammatory conditions.

    PubMed

    Cohen, E Suzanne; Bodmer, Helen C

    2003-05-01

    The human major histocompatibility complex (MHC) class I allele HLA-B27 is strongly associated with seronegative spondyloarthropathies including ankylosing spondylitis and reactive arthritis. Although of unknown aetiology, one hypothesis suggests that a cytotoxic T cell (CTL) response against a self-antigen at sites of inflammation, such as entheses or joints may be involved. The chondrocyte is one of the major specialized cell types found both in articular cartilage and cartilaginous entheses and therefore is a possible source of such an antigen. CTL recognition of these cells is a potential mechanism for inflammation and cartilage damage, both through direct lysis of chondrocytes and the secretion of pro-inflammatory cytokines such as tumour necrosis factor and interferon-gamma (IFN-gamma). We test the feasibility of this hypothesis by examining the ability of chondrocytes to present antigen to CTL in vitro. Chondrocytes isolated from the ribcages of mice did not constitutively express detectable levels of MHC class I by fluorescence-activated cell sorting analysis. In addition, they were resistant to lysis by alloreactive and influenza A virus nucleoprotein (NP)-specific CTL. However, treatment of chondrocytes with IFN-gamma up-regulated MHC class I expression and rendered the cells susceptible to lysis by CTL. Similarly, IFN-gamma-treated chondrocytes infected with influenza A virus were recognized by NP-specific CTL, though with variable efficiency. Thus, we suggest that under certain circumstances CTL-mediated lysis of chondrocytes is potentially a potent mechanism for cartilage damage in vivo, but that low levels of MHC class I on healthy chondrocytes protects from immune recognition in health. PMID:12709012

  15. Structural identity between HLA-A2 antigens differentially recognized by alloreactive cytotoxic T lymphocytes.

    PubMed

    Castaño, A R; Lauzurica, P; Domenech, N; López de Castro, J A

    1991-05-01

    Alloreactive CTL raised against HLA-A2 Ag often display heterogeneous recognition of HLA-A2+ target cells. This heterogeneity has been found to reflect structural polymorphism among the corresponding target Ag, thus defining HLA-A2 subtypes. A previous study (van der Poel et al. 1986. Human Immunol. 16:247) established the existence of a new HLA-A2.4 variant, A2-SCHU, that was distinguished from A*0206 (A2.4a) by HLA-A2-specific alloreactive CTL. The same CTL subdivided HLA-A2.1 Ag into two subgroups. In the present study, the molecular basis of this heterogeneity has been examined by double-label comparative peptide mapping analysis of differentially recognized A2.1 and A2.4 Ag. In addition, we have determined the complete sequence of polymerase chain reaction-amplified full length cDNA from A2-SCHU. The results show that: 1) A2-SCHU is indistinguishable from A*0206 by peptide mapping; 2) the cDNA sequence of A2-SCHU is identical to that of A*0206; and 3) two differentially recognized A2.1 Ag are both indistinguishable from A*0201 by comparative peptide mapping. These results indicate that differential recognition by alloreactive CTL can occur among structurally identical class I HLA Ag and suggest that allorecognition by such CTL may involve corecognition of endogenous peptides, presumably derived from polymorphic proteins. PMID:2016531

  16. Immunologic special forces: anti-pathogen cytotoxic T-lymphocyte immunotherapy following hematopoietic stem cell transplantation

    PubMed Central

    Keller, Michael D; Bollard, Catherine M

    2014-01-01

    Anti-pathogen adoptive T-cell immunotherapy has been proven to be highly effective in preventing or controlling viral infections following hematopoietic stem cell transplantation. Recent advances in manufacturing protocols allow an increased number of targeted pathogens, eliminate the need for viral transduction, broaden the potential donor pool to include pathogen-naïve sources, and reduce the time requirement for production. Early studies suggest that anti-fungal immunotherapy may also have clinical benefit. Future advances include further broadening of the pathogens that can be targeted and development of T-cells with resistance to pharmacologic immunosuppression. PMID:27274983

  17. Enhanced Anti-tumor Reactivity of Cytotoxic T Lymphocytes Expressing PD-1 Decoy.

    PubMed

    Shin, Jae Hun; Park, Hyung Bae; Choi, Kyungho

    2016-04-01

    Programmed death-1 (PD-1) is a strong negative regulator of T lymphocytes in tumor-microenvironment. By engaging PD-1 ligand (PD-L1) on tumor cells, PD-1 on T cell surface inhibits anti-tumor reactivity of tumor-infiltrating T cells. Systemic blockade of PD-1 function using blocking antibodies has shown significant therapeutic efficacy in clinical trials. However, approximately 10 to 15% of treated patients exhibited serious autoimmune responses due to the activation of self-reactive lymphocytes. To achieve selective activation of tumor-specific T cells, we generated T cells expressing a dominant-negative deletion mutant of PD-1 (PD-1 decoy) via retroviral transduction. PD-1 decoy increased IFN-γ secretion of antigen-specific T cells in response to tumor cells expressing the cognate antigen. Adoptive transfer of PD-1 decoy-expressing T cells into tumor-bearing mice potentiated T cell-mediated tumor regression. Thus, T cell-specific blockade of PD-1 could be a useful strategy for enhancing both efficacy and safety of anti-tumor T cell therapy. PMID:27162530

  18. A Well-Controlled Experimental System to Study Interactions of Cytotoxic T Lymphocytes with Tumor Cells

    PubMed Central

    Neubert, Natalie J.; Soneson, Charlotte; Barras, David; Baumgaertner, Petra; Rimoldi, Donata; Delorenzi, Mauro; Fuertes Marraco, Silvia A.; Speiser, Daniel E.

    2016-01-01

    While T cell-based immunotherapies are steadily improving, there are still many patients who progress, despite T cell-infiltrated tumors. Emerging evidence suggests that T cells themselves may provoke immune escape of cancer cells. Here, we describe a well-controlled co-culture system for studying the dynamic T cell – cancer cell interplay, using human melanoma as a model. We explain starting material, controls, and culture parameters to establish reproducible and comparable cultures with highly heterogeneous tumor cells. Low passage melanoma cell lines and melanoma-specific CD8+ T cell clones generated from patient blood were cultured together for up to 3 days. Living melanoma cells were isolated from the co-culture system by fluorescence-activated cell sorting. We demonstrate that the characterization of isolated melanoma cells is feasible using flow cytometry for protein expression analysis as well as an Agilent whole human genome microarray and the NanoString technology for differential gene expression analysis. In addition, we identify five genes (ALG12, GUSB, RPLP0, KRBA2, and ADAT2) that are stably expressed in melanoma cells independent of the presence of T cells or the T cell-derived cytokines IFNγ and TNFα. These genes are essential for correct normalization of gene expression data by NanoString. Further to the characterization of melanoma cells after exposure to CTLs, this experimental system might be suitable to answer a series of questions, including how the affinity of CTLs for their target antigen influences the melanoma cell response and whether CTL-induced gene expression changes in melanoma cells are reversible. Taken together, our human T cell – melanoma cell culture system is well suited to characterize immune-related mechanisms in cancer cells.

  19. Immunotherapy of cancer via mediation of cytotoxic T lymphocytes by methionine enkephalin (MENK).

    PubMed

    Li, Weiwei; Chen, Wenna; Herberman, Ronald B; Plotnikoff, Nicolas P; Youkilis, Gene; Griffin, Noreen; Wang, Enhua; Lu, Changlong; Shan, Fengping

    2014-03-28

    The aim of this study was to investigate the immunological mechanisms by which synthetic methionine enkephalin (MENK) exerts therapeutic effects on tumor growth. Our findings in vivo or in vitro show that MENK treatment either in vivo or in vitro could up-regulate the percentages of CD8+T cells, induce markers of activated T cells, increased cytotoxic activity against mouse S180 tumor cells and increase secretion of IFNγ. In addition, the adoptively transferred CD8+T cells, after either in vitro or in vivo treatment with MENK, result in significantly increased survival of S180 tumor-bearing mice and significant shrinkage in tumor growth. Opioid receptors are detected on normal CD8+T cells and exposure to MENK leads to increased expression of opioid receptors. Interaction between MENK and the opioid receptors on CD8+T cells appears to be essential for the activation of CTL, since the addition of naltrexone (NTX), an opioid receptor antagonist, significantly inhibits all of the effects of MENK. The evidence obtained indicates that the MENK-induced T cell signaling is associated with a significant up-regulation of Ca2+ influx into the cytoplasm and the translocation of NFAT2 into nucleus, and these signaling effects are also inhibited by naltrexone.

  20. Age-related decline of perforin expression in human cytotoxic T lymphocytes and natural killer cells.

    PubMed

    Rukavina, D; Laskarin, G; Rubesa, G; Strbo, N; Bedenicki, I; Manestar, D; Glavas, M; Christmas, S E; Podack, E R

    1998-10-01

    In this study a flow cytometric technique for detecting cytoplasmic perforin (P) has been used to quantify age-related changes in perforin expression in human peripheral blood lymphocytes (PBL). Proportions of P+ lymphocytes increased after birth, but declined rapidly after the age of 70 years. This was true for both T cells and CD16(+) and CD56(+) natural killer (NK) cells. Children showed in addition to high levels of perforin positive CD8(+) cells a much higher proportion of CD4(+)P+ cells than the other age groups. In elderly individuals there was also a highly significant reduction in mean levels of perforin per cell as compared with all other groups (P < .05 to .001). Adult women had consistently higher mean levels of perforin per cell than adult men for all P+ cell phenotypes. Functional tests clearly showed the deficiency in early spontaneous cytotoxic potential of PBL from elderly persons due to relative P deficiency, which can be corrected by stimulation of cytolytic cells with target cells and interleukin-2 (IL-2). The deficiency in cytolytic activity on the contact with target cells may have implications for antiviral and antitumor immunity in elderly persons.

  1. A validated model for induction heating of shape memory alloy actuators

    NASA Astrophysics Data System (ADS)

    Saunders, Robert N.; Boyd, James G.; Hartl, Darren J.; Brown, Jonathan K.; Calkins, Frederick T.; Lagoudas, Dimitris C.

    2016-04-01

    Shape memory alloy (SMA) actuators deliver high forces while being compact and reliable, making them ideal for consideration in aerospace applications. One disadvantage of these thermally driven actuators is their slow cyclic time response compared to conventional actuators. Induction heating has recently been proposed to quickly heat SMA components. However efforts to date have been purely empirical. The present work approachs this problem in a computational manner by developing a finite element model of induction heating in which the time-harmonic electromagnetic equations are solved for the Joule heat power field, the energy equation is solved for the temperature field, and the linear momentum equations are solved to find the stress, displacement, and internal state variable fields. The combined model was implemented in Abaqus using a Python script approach and applied to SMA torque tube and beam actuators. The model has also been used to examine magnetic flux concentrators to improve the induction systems performance. Induction heating experiments were performed using the SMA torque tube, and the model agreed well with the experiments.

  2. Inductively Heated Shape Memory Polymer for the Magnetic Actuation of Medical Devices

    SciTech Connect

    Buckley, P; Mckinley, G; Wilson, T; Small, W; Benett, W; Bearinger, J; McElfresh, M; Maitland, D

    2005-09-06

    Presently there is interest in making medical devices such as expandable stents and intravascular microactuators from shape memory polymer (SMP). One of the key challenges in realizing SMP medical devices is the implementation of a safe and effective method of thermally actuating various device geometries in vivo. A novel scheme of actuation by Curie-thermoregulated inductive heating is presented. Prototype medical devices made from SMP loaded with Nickel Zinc ferrite ferromagnetic particles were actuated in air by applying an alternating magnetic field to induce heating. Dynamic mechanical thermal analysis was performed on both the particle-loaded and neat SMP materials to assess the impact of the ferrite particles on the mechanical properties of the samples. Calorimetry was used to quantify the rate of heat generation as a function of particle size and volumetric loading of ferrite particles in the SMP. These tests demonstrated the feasibility of SMP actuation by inductive heating. Rapid and uniform heating was achieved in complex device geometries and particle loading up to 10% volume content did not interfere with the shape recovery of the SMP.

  3. Virus-induced polyclonal B cell activation improves protective CTL memory via retained CD27 expression on memory CTL.

    PubMed

    Matter, Matthias; Mumprecht, Sabine; Pinschewer, Daniel D; Pavelic, Viktor; Yagita, Hideo; Krautwald, Stefan; Borst, Jannie; Ochsenbein, Adrian F

    2005-11-01

    Different viruses elicit distinct phenotypes of memory cytotoxic T lymphocytes (CTL). This is reflected in differential expression of homing receptors and costimulatory molecules like CD27. Memory CTL retained CD27 following lymphocytic choriomeningitis virus (LCMV) infection, but not after immunization with recombinant vaccinia virus or tumor cells expressing LCMV glycoprotein. Stable CD27 expression on memory CTL required ligation by CD70 expressed on polyclonally activated B cells during the contraction phase. The functional consequence of CD27 expressed on virus-specific CTL was analyzed in CD27-deficient mice. LCMV infection of CD27(-/-) mice revealed that primary CTL activation and expansion as well as elimination of the virus were independent of CD27 expression. In contrast, ligation of CD27 on memory CTL upon secondary antigen encounter increased clonal expansion and improved protection against re-infection. This points to novel B cell-CTL interactions during viral infection and to a beneficial role of polyclonal B cell activation that represents a characteristic of murine LCMV, human immunodeficiency virus and human hepatitis B and C virus infection. PMID:16231287

  4. Induction of primary, antiviral cytotoxic, and proliferative responses with antigens administered via dendritic cells.

    PubMed Central

    Nair, S; Babu, J S; Dunham, R G; Kanda, P; Burke, R L; Rouse, B T

    1993-01-01

    Cytotoxic T lymphocytes (CTL) play an essential role in recovery from viral infections, but induction of CTL responses with nonreplicating antigens is difficult to achieve. Exogenous antigens, such as viral proteins and peptides, normally induce CD4+ T-cell responses unless appropriately delivered to the major histocompatibility complex class I antigen presentation pathway. In vitro studies performed to address this issue revealed a similar scenario, and primary CTL induction with nonreplicating antigens has rarely been reported. This study demonstrated primary antiviral CTL induction in vitro with exogenous antigens delivered in vivo to dendritic cells. This study also evaluated the efficacy of glycoprotein B peptide (free or encapsulated in liposomes), peptide-tripalmitoyl-S-glyceryl cysteinyl conjugate (acylpeptide), and glycoprotein B protein encapsulated in pH-sensitive liposomes as antigen delivery vehicles. Our results show that higher levels of cytotoxicity against herpes simplex virus type 1 resulted from exposure of dendritic cells to peptide-tripalmitoyl-S-glyceryl cysteinyl in liposomes. Macrophages treated in a similar manner were not effective stimulators for primary CTL induction. Our data have relevance to the understanding of mechanisms of antigen processing and presentation and the design of antiviral vaccines. PMID:8510217

  5. Expression profiling reveals differential gene induction underlying specific and non-specific memory for pheromones in mice.

    PubMed

    Upadhya, Sudarshan C; Smith, Thuy K; Brennan, Peter A; Mychaleckyj, Josyf C; Hegde, Ashok N

    2011-11-01

    Memory for the mating male's pheromones in female mice is thought to require synaptic changes in the accessory olfactory bulb (AOB). Induction of this memory depends on release of glutamate in response to pheromonal exposure coincident with release of norepinephrine (NE) in the AOB following mating. A similar memory for pheromones can also be induced artificially by local infusion of the GABA(A) receptor antagonist bicuculline into the AOB. The natural memory formed by exposure to pheromones during mating is specific to the pheromones sensed by the female during mating. In contrast, the artificial memory induced by bicuculline is non-specific and results in the female mice recognizing all pheromones as if they were from the mating male. Although protein synthesis has been shown to be essential for development of pheromone memory, the gene expression cascades critical for memory formation are not known. We investigated changes in gene expression in the AOB using oligonucleotide microarrays during mating-induced pheromone memory (MIPM) as well as bicuculline-induced pheromone memory (BIPM). We found the set of genes induced during MIPM and BIPM are largely non-overlapping and Ingenuity Pathway Analysis revealed that the signaling pathways in MIPM and BIPM also differ. The products of genes induced during MIPM are associated with synaptic function, indicating the possibility of modification at specific synapses, while those induced during BIPM appear to possess neuron-wide functions, which would be consistent with global cellular changes. Thus, these results begin to provide a mechanistic explanation for specific and non-specific memories induced by pheromones and bicuculline infusion respectively.

  6. Quiescence of Memory CD8(+) T Cells Is Mediated by Regulatory T Cells through Inhibitory Receptor CTLA-4.

    PubMed

    Kalia, Vandana; Penny, Laura Anne; Yuzefpolskiy, Yevgeniy; Baumann, Florian Martin; Sarkar, Surojit

    2015-06-16

    Immune memory cells are poised to rapidly expand and elaborate effector functions upon reinfection yet exist in a functionally quiescent state. The paradigm is that memory T cells remain inactive due to lack of T cell receptor (TCR) stimuli. Here, we report that regulatory T (Treg) cells orchestrate memory T cell quiescence by suppressing effector and proliferation programs through inhibitory receptor, cytotoxic-T-lymphocyte-associated protein-4 (CTLA-4). Loss of Treg cells resulted in activation of genome-wide transcriptional programs characteristic of effector T cells and drove transitioning as well as established memory CD8(+) T cells toward terminally differentiated KLRG-1(hi)IL-7Rα(lo)GzmB(hi) phenotype, with compromised metabolic fitness, longevity, polyfunctionality, and protective efficacy. CTLA-4 functionally replaced Treg cells in trans to rescue memory T cell defects and restore homeostasis. These studies present the CTLA-4-CD28-CD80/CD86 axis as a potential target to accelerate vaccine-induced immunity and improve T cell memory quality in current cancer immunotherapies proposing transient Treg cell ablation.

  7. Chemo-responsive shape memory effect in shape memory polyurethane triggered by inductive release of mechanical energy storage undergoing copper (II) chloride migration

    NASA Astrophysics Data System (ADS)

    Lu, Haibao; Lu, Chunrui; Huang, Wei Min; Leng, Jinsong

    2015-03-01

    In this study, 10% weight fraction of copper (II) chloride (CuCl2) was embedded into shape memory polyurethane (SMPU) by dissolving it in a solvent mixture of tetrahydrofuran and N,N-dimethyl formamide. It is found that CuCl2 particles migrate; they are released from the polymer in the water-driven shape recovery process of SMPU composites. SMPU composites, after various immersion times in water, were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. Experimental results support that hydrogen bonding between polyurethane macromolecules and water molecules is the driving force, resulting from the inductive decrease in the glass transition temperature. Furthermore, the release of the stored mechanical energy in SMPU is demonstrated by means of tracking the migration of CuCl2 particles via x-ray diffraction and scanning electron microscopy tests. This study focuses on the mechanism of release of the stored mechanical energy of a polymer, which is identified as the driving force for the chemo-responsive shape memory effect and inductive decrease in glass transition temperature of SMPU in response to the water.

  8. Processes of DNA methylation are involved in the mechanisms of amnesia induction and conditioned food aversion memory reconsolidation.

    PubMed

    Solntseva, S V; Filatova, T S; Nikitin, P V; Bredov, D V; Kozyrev, S A; Nikitin, V P

    2014-02-01

    We studied the role of DNA methylation in the mechanisms of amnesia in edible snails, which was induced by impairment of conditioned food aversion memory reconsolidation with NMDA glutamate receptor antagonist. The effects of DNA methyltransferase inhibitors were shown to depend on the stage of amnesia. At the early stage of amnesia (day 3 after induction), injections of methyltransferase inhibitors in combination with conditioned food stimulus (reminder) were followed by memory recovery. Application of inhibitors in the absence of the reminder was ineffective. Methyltransferase inhibitors were ineffective at the late stage of amnesia (day 10). Our results suggest that the presentation of reminding conditioned stimuli is followed by reactivation of amnesia. Methylation or demethylation of DNA in nerve cells serves as one of the key mechanisms for amnesia.

  9. Induction of an Olfactory Memory by the Activation of a Metabotropic Glutamate Receptor

    NASA Astrophysics Data System (ADS)

    Kaba, Hideto; Hayashi, Yasunori; Higuchi, Takashi; Nakanishi, Shigetada

    1994-07-01

    Female mice form an olfactory memory of male pheromones at mating; exposure to the pheromones of a strange male after that mating will block pregnancy. The formation of this memory is mediated by the accessory olfactory system, in which an increase in norepinephrine after mating reduces inhibitory transmission of γ-aminobutyric acid from the granule cells to the mitral cells. This study shows that the activation of mGluR2, a metabotropic glutamate receptor that suppresses the γ-aminobutyric acid inhibition of the mitral cells, permits the formation of a specific olfactory memory without the occurrence of mating by infusion of mGluR2 agonists into the female's accessory olfactory bulb. This memory faithfully reflects the memory formed at mating.

  10. Chronic stress-induced memory deficits are reversed by regular exercise via AMPK-mediated BDNF induction.

    PubMed

    Kim, D-M; Leem, Y-H

    2016-06-01

    Chronic stress has a detrimental effect on neurological insults, psychiatric deficits, and cognitive impairment. In the current study, chronic stress was shown to impair learning and memory functions, in addition to reducing in hippocampal Adenosine monophosphate-activated protein kinase (AMPK) activity. Similar reductions were also observed for brain-derived neurotrophic factor (BDNF), synaptophysin, and post-synaptic density-95 (PSD-95) levels, all of which was counter-regulated by a regime of regular and prolonged exercise. A 21-day restraint stress regimen (6 h/day) produced learning and memory deficits, including reduced alternation in the Y-maze and decreased memory retention in the water maze test. These effects were reversed post-administration by a 3-week regime of treadmill running (19 m/min, 1 h/day, 6 days/week). In hippocampal primary culture, phosphorylated-AMPK (phospho-AMPK) and BDNF levels were enhanced in a dose-dependent manner by 5-amimoimidazole-4-carboxamide riboside (AICAR) treatment, and AICAR-treated increase was blocked by Compound C. A 7-day period of AICAR intraperitoneal injections enhanced alternation in the Y-maze test and reduced escape latency in water maze test, along with enhanced phospho-AMPK and BDNF levels in the hippocampus. The intraperitoneal injection of Compound C every 4 days during exercise intervention diminished exercise-induced enhancement of memory improvement during the water maze test in chronically stressed mice. Also, chronic stress reduced hippocampal neurogenesis (lower Ki-67- and doublecortin-positive cells) and mRNA levels of BDNF, synaptophysin, and PSD-95. Our results suggest that regular and prolonged exercise can alleviate chronic stress-induced hippocampal-dependent memory deficits. Hippocampal AMPK-engaged BDNF induction is at least in part required for exercise-induced protection against chronic stress. PMID:26975895

  11. Chronic stress-induced memory deficits are reversed by regular exercise via AMPK-mediated BDNF induction.

    PubMed

    Kim, D-M; Leem, Y-H

    2016-06-01

    Chronic stress has a detrimental effect on neurological insults, psychiatric deficits, and cognitive impairment. In the current study, chronic stress was shown to impair learning and memory functions, in addition to reducing in hippocampal Adenosine monophosphate-activated protein kinase (AMPK) activity. Similar reductions were also observed for brain-derived neurotrophic factor (BDNF), synaptophysin, and post-synaptic density-95 (PSD-95) levels, all of which was counter-regulated by a regime of regular and prolonged exercise. A 21-day restraint stress regimen (6 h/day) produced learning and memory deficits, including reduced alternation in the Y-maze and decreased memory retention in the water maze test. These effects were reversed post-administration by a 3-week regime of treadmill running (19 m/min, 1 h/day, 6 days/week). In hippocampal primary culture, phosphorylated-AMPK (phospho-AMPK) and BDNF levels were enhanced in a dose-dependent manner by 5-amimoimidazole-4-carboxamide riboside (AICAR) treatment, and AICAR-treated increase was blocked by Compound C. A 7-day period of AICAR intraperitoneal injections enhanced alternation in the Y-maze test and reduced escape latency in water maze test, along with enhanced phospho-AMPK and BDNF levels in the hippocampus. The intraperitoneal injection of Compound C every 4 days during exercise intervention diminished exercise-induced enhancement of memory improvement during the water maze test in chronically stressed mice. Also, chronic stress reduced hippocampal neurogenesis (lower Ki-67- and doublecortin-positive cells) and mRNA levels of BDNF, synaptophysin, and PSD-95. Our results suggest that regular and prolonged exercise can alleviate chronic stress-induced hippocampal-dependent memory deficits. Hippocampal AMPK-engaged BDNF induction is at least in part required for exercise-induced protection against chronic stress.

  12. Cross reactive cytotoxic T lymphocytes from MHC-defined birds against homologous and heterologous avian influenza subtypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous reports have implicated a role of the major-histocompatibility complex (MHC) in genetic resistance of chickens to bacterial infection and viral diseases. However, little is known about the role of MHC in generating protective immunity following avian influenza (AI) infection. Because vacc...

  13. Monoclonal antibody against IFN-gamma inhibits Moloney murine sarcoma virus-specific cytotoxic T lymphocyte differentiation

    SciTech Connect

    Zanovello, P.; Vallerani, E.; Biasi, G.; Landolfo, S.; Collavo, D.

    1988-02-15

    The role of autochthonous IFN- production was evaluated in immune reactions to Moloney murine sarcoma virus (M-MSV)-induced tumors which are characterized by spontaneous regression mainly caused by virus-specific CTL activity. A functional IFN- depletion, induced by repeated administration of mAb anti-IFN- at the site of virus inoculation, prevented tumor regression in M-MSV-injected mice. Moreover, this antibody inhibited in vitro both proliferation and differentiation of M-MSV-specific T lymphocytes obtained in bulk cultures, but not growth and lytic activity of the already differentiated virus-specific CTL clone CHM-14 stimulated with rIL-2 and relevant tumor Ag. In addition, in mice receiving mAb treatment the frequency of M-MSV-specific CTL precursors, evaluated by means of limiting dilution analysis, was strongly reduced in comparison with that of control mice injected only with virus. Because CTL secrete IFN- following antigenic stimulation, the possibility that non-T effector cells recruited by this lymphokine might mediate tumor regression was also considered. Adoptive immunotherapy experiments, performed in T cell-deficient (Tx + BM) and in sublethally irradiated mice, demonstrated that transfer of CHM-14 CTL clone, which secretes IFN-, was able to counteract M-MSV tumor growth despite the local mAb anti-IFN- treatment which may have prevented host cell recruitment. Moreover, repeated local rIFN- inoculations in Tx + BM mice did not counteract M-MSV tumor progression, thus confirming that other IFN- properties such as non-T cell recruitment, antiviral or anti-proliferative IFN- activities have little or no relevance when M-MSV-specific CTL are lacking. On the whole, these results indicate that in M-MSV-injected mice, tumor enhancement after mAb anti-IFN- treatment is principally caused by impaired differentiation of virus-specific CTL precursors.

  14. Global Gene Expression Profiling in Interleukin-12-Induced Activation of CD8+ Cytotoxic T Lymphocytes against Mouse Mammary Carcinoma

    PubMed Central

    Cao, Shanjin; Xiang, Zhaoying; Ma, Xiaojing

    2010-01-01

    Interleukin-12 (IL-12) is a critical cytokine representing the link between the cellular and humoral branches of host immune defense apparatus. IL-12-induced cytotoxic lymphocyte (CTL) development is a central mechanism in immune responses against intracellular infectious agents as well as malignant growth. However, the molecular basis of tumor-specific CTL responses mediated by IL-12 remains poorly defined. In this study, we addressed this issue in a comprehensive manner to probe into IL-12-induced anti-tumor responses by global gene expression profiling of mRNA expression in CD8+T cells in a transplantable syngeneic mouse mammary carcinoma model treated or not with recombinant IL-12. A strong tumor regression was induced by the IL-12 treatment. An introspection of differential gene expression at an early stage of the IL-12-initiated CTL activation reveals interesting genes and molecular pathways that may account for the marked tumor regression, and is likely to provide a rich source of potential targets for further research and development of effective therapeutic modalities. PMID:16285895

  15. CMRF-56(+) blood dendritic cells loaded with mRNA induce effective antigen-specific cytotoxic T-lymphocyte responses.

    PubMed

    Fromm, Phillip D; Papadimitrious, Michael S; Hsu, Jennifer L; Van Kooten Losio, Nicolas; Verma, Nirupama D; Lo, Tsun Ho; Silveira, Pablo A; Bryant, Christian E; Turtle, Cameron J; Prue, Rebecca L; Vukovic, Peter; Munster, David J; Nagasaki, Tomoko; Barnard, Ross T; Mahler, Stephen M; Anguille, Sébastien A; Berneman, Zwi; Horvath, Lisa G; Bradstock, Kenneth F; Joshua, Douglas E; Clark, Georgina J; Hart, Derek N J

    2016-06-01

    There are numerous transcriptional, proteomic and functional differences between monocyte-derived dendritic cells (Mo-DC) and primary blood dendritic cells (BDC). The CMRF-56 monoclonal antibody (mAb) recognizes a cell surface marker, which is upregulated on BDC following overnight culture. Given its unique ability to select a heterogeneous population of BDC, we engineered a human chimeric (h)CMRF-56 IgG4 mAb to isolate primary BDC for potential therapeutic vaccination. The ability to select multiple primary BDC subsets from patients and load them with in vitro transcribed (IVT) mRNA encoding tumor antigen might circumvent the issues limiting the efficacy of Mo-DC. After optimizing and validating the purification of hCMRF-56(+) BDC, we showed that transfection of hCMRF-56(+) BDC with mRNA resulted in efficient mRNA translation and antigen presentation by myeloid BDC subsets, while preserving superior DC functions compared to Mo-DC. Immune selected and transfected hCMRF-56(+) BDC migrated very efficiently in vitro and as effectively as cytokine matured Mo-DC in vivo. Compared to Mo-DC, hCMRF-56(+) BDC transfected with influenza matrix protein M1 displayed superior MHC peptide presentation and generated potent antigen specific CD8(+) T-cell recall responses, while Wilms tumor 1 (WT1) transfected CMRF-56(+) BDC generated effective primary autologous cytotoxic T-cell responses. The ability of the combined DC subsets within hCMRF-56(+) BDC to present mRNA delivered tumor antigens merits phase I evaluation as a reproducible generic platform for the next generation of active DC immune therapies. PMID:27471645

  16. Increased breadth and depth of cytotoxic T lymphocytes responses against HIV-1-B Nef by inclusion of epitope variant sequences.

    PubMed

    Rolland, Morgane; Frahm, Nicole; Nickle, David C; Jojic, Nebojsa; Deng, Wenjie; Allen, Todd M; Brander, Christian; Heckerman, David E; Mullins, James I

    2011-03-28

    Different vaccine approaches cope with HIV-1 diversity, ranging from centralized(1-4) to variability-encompassing(5-7) antigens. For all these strategies, a concern remains: how does HIV-1 diversity impact epitope recognition by the immune system? We studied the relationship between HIV-1 diversity and CD8(+) T Lymphocytes (CTL) targeting of HIV-1 subtype B Nef using 944 peptides (10-mers overlapping by nine amino acids (AA)) that corresponded to consensus peptides and their most common variants in the HIV-1-B virus population. IFN-γ ELISpot assays were performed using freshly isolated PBMC from 26 HIV-1-infected persons. Three hundred and fifty peptides elicited a response in at least one individual. Individuals targeted a median of 7 discrete regions. Overall, 33% of responses were directed against viral variants but not elicited against consensus-based test peptides. However, there was no significant relationship between the frequency of a 10-mer in the viral population and either its frequency of recognition (Spearman's correlation coefficient ρ = 0.24) or the magnitude of the responses (ρ = 0.16). We found that peptides with a single mutation compared to the consensus were likely to be recognized (especially if the change was conservative) and to elicit responses of similar magnitude as the consensus peptide. Our results indicate that cross-reactivity between rare and frequent variants is likely to play a role in the expansion of CTL responses, and that maximizing antigenic diversity in a vaccine may increase the breadth and depth of CTL responses. However, since there are few obvious preferred pathways to virologic escape, the diversity that may be required to block all potential escape pathways may be too large for a realistic vaccine to accommodate. Furthermore, since peptides were not recognized based on their frequency in the population, it remains unclear by which mechanisms variability-inclusive antigens (i.e., constructs enriched with frequent variants) expand CTL recognition.

  17. Fetal liver T cell receptor gamma/delta+ T cells as cytotoxic T lymphocytes specific for maternal alloantigens

    PubMed Central

    1992-01-01

    We have established fetal liver-derived T cell receptor (TCR) gamma/delta+, CD3+ T cell lines that are cytotoxic for maternal T cells. Fetal liver-derived lymphoid progenitors yielded predominantly TCR-gamma/delta+ cell clusters when cultured on fetal bone marrow- derived stromal cells in the presence of a cytokine cocktail under magnetic force. These tightly adherent clusters were cloned by limiting dilution and the resulting cell lines analyzed for phenotype and function. Six of eight TCR-gamma/delta lines from 8-9.5-wk gestation fetuses were V delta 2+ as compared with zero of eight lines from later stages of gestation (10 and 15 wk), where all the lines were V delta 1+. In cytotoxicity assays, these TCR-gamma/delta+, CD3+, CD4-, and CD8+ or CD8- long-term cultured lymphoid cells (LLC) were killer cells active against the class I antigens on maternal T cells. Of the cell lines, the CD8+ TCR-gamma/delta+ LLC had the highest levels of killer activity. Thus fetal liver TCR-gamma/delta+ T cells may play a crucial role in protection against invading maternal T cells generated in the feto-maternal interaction. PMID:1535364

  18. Activation of CD8-dependent cytotoxic T lymphocyte adhesion and degranulation by peptide class I antigen complexes.

    PubMed

    Kane, K P; Mescher, M F

    1993-06-01

    Activation of CTL requires engagement of both the TCR and the CD8 coreceptor. Immobilized class I proteins and in vitro-formed peptide class I Ag complexes have been used to examine the relative contributions of TCR and CD8 to the adhesion and response of cloned, class I-restricted CTL. The extent of degranulation was found to be directly proportional to the concentration of peptide used to pulse class I, suggesting that activation is a direct function of TCR occupancy level. In contrast, activation of degranulation as a function of the amount of class I on the surface displayed a marked threshold density dependence. Essentially the same density dependence was found for the response of CTL to fluid phase anti-TCR mAb and non-Ag class I, indicating that CD8-class I interaction must exceed a threshold before effective cosignaling can occur. Adhesion and degranulation of CTL was minimal in response to in vitro peptide-class I complexes prepared at a class I density below the threshold. However, the same density of peptide class I initiated both adhesion and response if additional non-Ag class I was coimmobilized on the same surface at levels above threshold. Thus, when surface levels of peptide class I complex are low, as is likely to be the case under physiologic conditions, the level of TCR occupancy achieved is, by itself, insufficient to mediate cell adhesion or activate degranulation. The results demonstrate, however, that low TCR occupancy is sufficient to provide the signal to prime CD8. Provided that the surface density of class I is sufficiently high, CD8 then mediates strong adhesion and provides the costimulatory signal(s) to activate response.

  19. Adoptive transfer of autologous, HER2-specific, cytotoxic T lymphocytes for the treatment of HER2-overexpressing breast cancer.

    PubMed

    Bernhard, Helga; Neudorfer, Julia; Gebhard, Kerstin; Conrad, Heinke; Hermann, Christine; Nährig, Jörg; Fend, Falko; Weber, Wolfgang; Busch, Dirk H; Peschel, Christian

    2008-02-01

    The human epidermal growth factor receptor 2 (HER2) has been targeted as a breast cancer-associated antigen by immunotherapeutical approaches based on HER2-directed monoclonal antibodies and cancer vaccines. We describe the adoptive transfer of autologous HER2-specific T-lymphocyte clones to a patient with metastatic HER2-overexpressing breast cancer. The HLA/multimer-based monitoring of the transferred T lymphocytes revealed that the T cells rapidly disappeared from the peripheral blood. The imaging studies indicated that the T cells accumulated in the bone marrow (BM) and migrated to the liver, but were unable to penetrate into the solid metastases. The disseminated tumor cells in the BM disappeared after the completion of adoptive T-cell therapy. This study suggests the therapeutic potential for HER2-specific T cells for eliminating disseminated HER2-positive tumor cells and proposes the combination of T cell-based therapies with strategies targeting the tumor stroma to improve T-cell infiltration into solid tumors. PMID:17646988

  20. Cytotoxic T lymphocytes block tumor growth both by lytic activity and IFNγ-dependent cell-cycle arrest.

    PubMed

    Matsushita, Hirokazu; Hosoi, Akihiro; Ueha, Satoshi; Abe, Jun; Fujieda, Nao; Tomura, Michio; Maekawa, Ryuji; Matsushima, Kouji; Ohara, Osamu; Kakimi, Kazuhiro

    2015-01-01

    To understand global effector mechanisms of CTL therapy, we performed microarray gene expression analysis in a murine model using pmel-1 T-cell receptor (TCR) transgenic T cells as effectors and B16 melanoma cells as targets. In addition to upregulation of genes related to antigen presentation and the MHC class I pathway, and cytotoxic effector molecules, cell-cycle-promoting genes were downregulated in the tumor on days 3 and 5 after CTL transfer. To investigate the impact of CTL therapy on the cell cycle of tumor cells in situ, we generated B16 cells expressing a fluorescent ubiquitination-based cell-cycle indicator (B16-fucci) and performed CTL therapy in mice bearing B16-fucci tumors. Three days after CTL transfer, we observed diffuse infiltration of CTLs into the tumor with a large number of tumor cells arrested at the G1 phase of the cell cycle, and the presence of spotty apoptotic or necrotic areas. Thus, tumor growth suppression was largely dependent on G1 cell-cycle arrest rather than killing by CTLs. Neutralizing antibody to IFNγ prevented both tumor growth inhibition and G1 arrest. The mechanism of G1 arrest involved the downregulation of S-phase kinase-associated protein 2 (Skp2) and the accumulation of its target cyclin-dependent kinase inhibitor p27 in the B16-fucci tumor cells. Because tumor-infiltrating CTLs are far fewer in number than the tumor cells, we propose that CTLs predominantly regulate tumor growth via IFNγ-mediated profound cytostatic effects rather than via cytotoxicity. This dominance of G1 arrest over other mechanisms may be widespread but not universal because IFNγ sensitivity varied among tumors.

  1. Memory

    MedlinePlus

    ... it has to decide what is worth remembering. Memory is the process of storing and then remembering this information. There are different types of memory. Short-term memory stores information for a few ...

  2. Mechanisms contributing to the induction and storage of Pavlovian fear memories in the lateral amygdala

    PubMed Central

    Kim, Dongbeom; Paré, Denis; Nair, Satish S.

    2013-01-01

    The relative contributions of plasticity in the amygdala vs. its afferent pathways to conditioned fear remain controversial. Some believe that thalamic and cortical neurons transmitting information about the conditioned stimulus (CS) to the lateral amygdala (LA) serve a relay function. Others maintain that thalamic and/or cortical plasticity is critically involved in fear conditioning. To address this question, we developed a large-scale biophysical model of the LA that could reproduce earlier findings regarding the cellular correlates of fear conditioning in LA. We then conducted model experiments that examined whether fear memories depend on (1) training-induced increases in the responsiveness of thalamic and cortical neurons projecting to LA, (2) plasticity at the synapses they form in LA, and/or (3) plasticity at synapses between LA neurons. These tests revealed that training-induced increases in the responsiveness of afferent neurons are required for fear memory formation. However, once the memory has been formed, this factor is no longer required because the efficacy of the synapses that thalamic and cortical neurons form with LA cells has augmented enough to maintain the memory. In contrast, our model experiments suggest that plasticity at synapses between LA neurons plays a minor role in maintaining the fear memory. PMID:23864645

  3. Memory.

    ERIC Educational Resources Information Center

    McKean, Kevin

    1983-01-01

    Discusses current research (including that involving amnesiacs and snails) into the nature of the memory process, differentiating between and providing examples of "fact" memory and "skill" memory. Suggests that three brain parts (thalamus, fornix, mammilary body) are involved in the memory process. (JN)

  4. Memory-enhancing effect of Mori Fructus via induction of nerve growth factor.

    PubMed

    Kim, Hyo Geun; Oh, Myung Sook

    2013-07-14

    Fruits rich in phytochemicals have been shown to improve memory by protecting or enhancing neuronal functions mediated by neurotrophic factors, such as nerve growth factor (NGF), in the hippocampus. Mori Fructus (Morus alba L., Moraceae), also called mulberry, is used as a food, dietary supplement and an anti-ageing agent in traditional Oriental medicine. It is also known to contain abundant flavonoid compounds and to exhibit various pharmacological effects. The present study was performed to evaluate the memory-enhancing effect of Mori Fructus extract (ME) in mice, with a focus on NGF regulation. ME (20, 100 and 500 mg/kg per d for 7 d, per os) dose-dependently promoted NGF release in the mouse hippocampus, leading to phosphorylation of extracellular signal-regulated kinases and cyclic AMP response element-binding protein. ME significantly increased pre- and post-synapse formation, acetylcholine synthesisation, neuronal cell differentiation, neurite outgrowth and neuronal cell proliferation in the mouse hippocampus. Furthermore, ME significantly increased latency time in the passive avoidance task (P< 0·001) and recognition time of novel objects in the object recognition test (P< 0·05), indicating improvements in learning and memory. Taken together, these data suggest that ME exhibits a memory-enhancing effect via up-regulation of NGF.

  5. Effect of hydrogenation on the memory properties of Si nanocrystals obtained by inductively coupled plasma chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Cha, Young-Kwan; Park, Sangjin; Park, Youngsoo; Yoo, In-Kyeong; Cha, Daigil; Shin, Jung H.; Choi, Suk-Ho

    2006-11-01

    Effect of hydrogenation on memory properties has been studied for metal-oxide-semiconductor (MOS) structures with Si nanocrystals fabricated using inductively coupled plasma chemical vapor deposition and subsequent annealing. Hydrogenation induces a drastic increase of a dip in the quasistatic capacitance-voltage (C-V) curve of the MOS capacitor, caused by the reduction of the interface states due to hydrogen passivation. This is consistent with high-frequency C-V measurements showing more well-defined curves with less distortion in hydrogenated samples. After hydrogenation, the MOS device shows a significantly larger decrease of flatband voltage shift in electron charging than in hole charging, indicating more effective passivation of the defect states related to the electron charging. A longer retention time is found for electron charging after hydrogenation, but almost no change of charge loss rate for hole charging. These results suggest that an asymmetry exists in the effect of hydrogenation between electron and hole storage.

  6. Improving potato drought tolerance through the induction of long-term water stress memory.

    PubMed

    Ramírez, D A; Rolando, J L; Yactayo, W; Monneveux, P; Mares, V; Quiroz, R

    2015-09-01

    Knowledge of drought tolerance in potato is limited and very little is known about stress memory in this crop. In the present study, long-term stress memory was tested on tuber yield and drought tolerance related traits in three potato varieties (Unica, Désirée and Sarnav) with contrasted yields under water restriction. Seed tubers produced by plants grown under non-restricted (non-primed tubers) and restricted (primed tubers) water conditions were sown and exposed to similar watering treatments. Tuber yield and leaf greenness of plants from primed and non-primed seeds as well as tuber carbon isotope discrimination (Δ(13)C) and antioxidant activity (AA) responses to watering treatments were compared. Higher tuber yield, both under non-restricted and restricted water regimes, was produced by primed Sarnav plants. The decrease of tuber yield and Δ(13)C with water restriction was lower in primed Unica plants. Long-term stress memory consequently appears to be highly genotype-dependent in potato. Its expression in plants originated from primed tubers and facing water restriction seems to be positively associated to the degree of inherent capability of the cultivar to yield under water restriction. However, other effects of priming appear to be genotype-independent as priming enhanced the tuber AA in response to water restriction in the three varieties.

  7. Epigenetic memory gained by priming with osteogenic induction medium improves osteogenesis and other properties of mesenchymal stem cells

    PubMed Central

    Rui, Yunfeng; Xu, Liangliang; Chen, Rui; Zhang, Ting; Lin, Sien; Hou, Yonghui; Liu, Yang; Meng, Fanbiao; Liu, Zhenqing; Ni, Ming; Sze Tsang, Kam; Yang, Fuyuan; Wang, Chen; Chang Chan, Hsiao; Jiang, Xiaohua; Li, Gang

    2015-01-01

    Mesenchymal stem cells (MSCs) are highly plastic cells that are able to transdifferentiate or dedifferentiate under appropriate conditions. In the present study, we reported here that after in vitro induction of osteogenic differentiation, MSCs could be reverted to a primitive stem cell population (dedifferentiated osteogenic MSCs, De-Os-MSCs) with improved cell survival, colony formation, osteogenic potential, migratory capacity and increased expression of Nanog, Oct4 and Sox2. Most importantly, our results showed great superiority of the De-Os-MSCs over untreated MSCs in ectopic bone formation in vivo. Furthermore, Nanog-knockdown in MSCs could reverse these enhanced properties in De-Os-MSCs in vitro, indicating a central role of Nanog in the transcriptional network. In addition, epigenetic regulations including DNA methylation and histone modifications may play important roles in regulating the de-osteogenic differentiation process. And we found decreased methylation and promoter accrual of activating histone marks, such as H3K4me3 and H4ac on both Nanog and Oct4 gene promoters. Taken together, our study demonstrated that epigenetic memory in De-Os-MSCs gained by priming with osteogenic induction medium favored their differentiation along osteoblastic lineage with improved cell survival and migratory abilities, which may have application potential in enhancing their regenerative capacity in mammals. PMID:26053250

  8. Epigenetic memory gained by priming with osteogenic induction medium improves osteogenesis and other properties of mesenchymal stem cells.

    PubMed

    Rui, Yunfeng; Xu, Liangliang; Chen, Rui; Zhang, Ting; Lin, Sien; Hou, Yonghui; Liu, Yang; Meng, Fanbiao; Liu, Zhenqing; Ni, Ming; Tsang, Kam Sze; Yang, Fuyuan; Wang, Chen; Chan, Hsiao Chang; Jiang, Xiaohua; Li, Gang

    2015-01-01

    Mesenchymal stem cells (MSCs) are highly plastic cells that are able to transdifferentiate or dedifferentiate under appropriate conditions. In the present study, we reported here that after in vitro induction of osteogenic differentiation, MSCs could be reverted to a primitive stem cell population (dedifferentiated osteogenic MSCs, De-Os-MSCs) with improved cell survival, colony formation, osteogenic potential, migratory capacity and increased expression of Nanog, Oct4 and Sox2. Most importantly, our results showed great superiority of the De-Os-MSCs over untreated MSCs in ectopic bone formation in vivo. Furthermore, Nanog-knockdown in MSCs could reverse these enhanced properties in De-Os-MSCs in vitro, indicating a central role of Nanog in the transcriptional network. In addition, epigenetic regulations including DNA methylation and histone modifications may play important roles in regulating the de-osteogenic differentiation process. And we found decreased methylation and promoter accrual of activating histone marks, such as H3K4me3 and H4ac on both Nanog and Oct4 gene promoters. Taken together, our study demonstrated that epigenetic memory in De-Os-MSCs gained by priming with osteogenic induction medium favored their differentiation along osteoblastic lineage with improved cell survival and migratory abilities, which may have application potential in enhancing their regenerative capacity in mammals. PMID:26053250

  9. Intradermal Gene Immunization: The Possible Role of DNA Uptake in the Induction of Cellular Immunity to Viruses

    NASA Astrophysics Data System (ADS)

    Raz, Eyal; Carson, Dennis A.; Parker, Suezanne E.; Parr, Tyler B.; Abai, Anna M.; Aichinger, Gerald; Gromkowski, Stanislaw H.; Singh, Malini; Lew, Denise; Yankauckas, Michelle A.; Baird, Stephen M.; Rhodes, Gary H.

    1994-09-01

    The skin and mucous membranes are the anatomical sites where most viruses are first encountered by the immune system. Previous experiments have suggested that striated muscle cells are unique among mammalian cell types in their capacity to take up and express free DNA in the absence of a viral vector or physical carrier. However, we have found that mice injected into the superficial skin with free (naked) plasmid DNA encoding the influenza nucleoprotein gene had discrete foci of epidermal and dermal cells, including cells with dendritic morphology, that contained immunoreactive nucleoprotein antigen. A single intradermal administration of 0.3-15 μ g of free plasmid DNA induced anti-nucleoprotein-specific antibody and cytotoxic T lymphocytes that persisted for at least 68-70 weeks after vaccination. Intradermal gene administration induced higher antibody titers than did direct gene injection into skeletal muscle and did not cause local inflammation or necrosis. Compared with control animals, the gene-injected mice were resistant to challenge with a heterologous strain of influenza virus. These results indicate that the cells of the skin can take up and express free foreign DNA and induce cellular and humoral immune responses against the encoded protein. We suggest that DNA uptake by the skin-associated lymphoid tissues may play a role in the induction of cytotoxic T cells against viruses and other intracellular pathogens.

  10. Post-weaning mice fed exclusively milk have deficits in induction of long-term depression in the CA1 hippocampal region and spatial learning and memory.

    PubMed

    Nishie, Hideaki; Miyata, Ryouhei; Fujikawa, Ryu; Kinoshita, Ken-ichi; Muroi, Yoshikage; Ishii, Toshiaki

    2012-08-01

    Previously, we have found that post-weaning mice fed exclusively milk display low-frequency exploratory behavior compared to mice fed a food pellet diet (Ishii et al., 2005a). Because cognitive functions play a key role in animal exploration, in the present study we examined the effect of an exclusively milk formula diet on spatial learning and memory in a water maze and also on induction of long-term potentiation (LTP) and long-term depression (LTD) at the Schaffer collateral-CA1 synapse in the hippocampus. Exclusively milk-fed mice exhibited slower learning and memory deficits in hidden water maze tests as compared with pellet-fed mice. Moreover, milk-fed mice showed a significant inhibition of LTD but a normal induction of LTP. Despite these functional deficits, adult neurogenesis in the dentate gyrus of the hippocampus, which has been proposed to have a causal relationship to spatial memory, was stimulated in milk-fed mice. These result suggest that an exclusively milk formula diet after weaning leads to a stimulation of hippocampal neurogenesis but causes deficits in the induction of LTD in the CA1 hippocampal region and impairment of spatial learning and memory.

  11. Serine protease inhibitor-6 differentially affects the survival of effector and memory alloreactive CD8-T cells.

    PubMed

    Azzi, J; Ohori, S; Ting, C; Uehara, M; Abdoli, R; Smith, B D; Safa, K; Solhjou, Z; Lukyanchykov, P; Patel, J; McGrath, M; Abdi, R

    2015-01-01

    The clonal expansion of effector T cells and subsequent generation of memory T cells are critical in determining the outcome of transplantation. While cytotoxic T lymphocytes induce direct cytolysis of target cells through secretion of Granzyme-B (GrB), they also express cytoplasmic serine protease inhibitor-6 (Spi6) to protect themselves from GrB that has leaked from granules. Here, we studied the role of GrB/Spi6 axis in determining clonal expansion of alloreactive CD8-T cells and subsequent generation of memory CD8-T cells in transplantation. CD8-T cells from Spi6(-/-) mice underwent more GrB mediated apoptosis upon alloantigen stimulation in vitro and in vivo following adoptive transfer into an allogeneic host. Interestingly, while OT1.Spi6(-/-) CD8 T cells showed significantly lower clonal expansion following skin transplants from OVA mice, there was no difference in the size of the effector memory CD8-T cells long after transplantation. Furthermore, lack of Spi6 resulted in a decrease of short-lived-effector-CD8-cells but did not impact the pool of memory-precursor-effector-CD8-cells. Similar results were found in heart transplant models. Our findings suggest that the final alloreactive CD8-memory-pool-size is independent from the initial clonal-proliferation as memory precursors express low levels of GrB and therefore are independent of Spi6 for survival. These data advance our understanding of memory T cells generation in transplantation and provide basis for Spi6 based strategies to target effector T cells.

  12. Serine Protease Inhibitor-6 Differentially Affects the Survival of Effector and Memory Alloreactive CD8-T Cells

    PubMed Central

    Azzi, J.; Ohori, S.; Ting, C.; Uehara, M.; Abdoli, R.; Smith, B. D.; Safa, K.; Solhjou, Z.; Lukyanchykov, P.; Patel, J.; McGrath, M.; Abdi, R.

    2016-01-01

    The clonal expansion of effector T cells and subsequent generation of memory T cells are critical in determining the outcome of transplantation. While cytotoxic T lymphocytes induce direct cytolysis of target cells through secretion of Granzyme-B (GrB), they also express cytoplasmic serine protease inhibitor-6 (Spi6) to protect themselves from GrB that has leaked from granules. Here, we studied the role of GrB/Spi6 axis in determining clonal expansion of alloreactive CD8-T cells and subsequent generation of memory CD8-T cells in transplantation. CD8-T cells from Spi6−/− mice underwent more GrB mediated apoptosis upon alloantigen stimulation in vitro and in vivo following adoptive transfer into an allogeneic host. Interestingly, while OT1.Spi6−/− CD8 T cells showed significantly lower clonal expansion following skin transplants from OVA mice, there was no difference in the size of the effector memory CD8-T cells long after transplantation. Furthermore, lack of Spi6 resulted in a decrease of short-lived-effector-CD8-cells but did not impact the pool of memory-precursor-effector-CD8-cells. Similar results were found in heart transplant models. Our findings suggest that the final alloreactive CD8-memory-pool-size is independent from the initial clonal-proliferation as memory precursors express low levels of GrB and therefore are independent of Spi6 for survival. These data advance our understanding of memory T cells generation in transplantation and provide basis for Spi6 based strategies to target effector T cells. PMID:25534448

  13. On the validity of the autobiographical emotional memory task for emotion induction.

    PubMed

    Mills, Caitlin; D'Mello, Sidney

    2014-01-01

    The Autobiographical Emotional Memory Task (AEMT), which involves recalling and writing about intense emotional experiences, is a widely used method to experimentally induce emotions. The validity of this method depends upon the extent to which it can induce specific desired emotions (intended emotions), while not inducing any other (incidental) emotions at different levels across one (or more) conditions. A review of recent studies that used this method indicated that most studies exclusively monitor post-writing ratings of the intended emotions, without assessing the possibility that the method may have differentially induced other incidental emotions as well. We investigated the extent of this issue by collecting both pre- and post-writing ratings of incidental emotions in addition to the intended emotions. Using methods largely adapted from previous studies, participants were assigned to write about a profound experience of anger or fear (Experiment 1) or happiness or sadness (Experiment 2). In line with previous research, results indicated that intended emotions (anger and fear) were successfully induced in the respective conditions in Experiment 1. However, disgust and sadness were also induced while writing about an angry experience compared to a fearful experience. Similarly, although happiness and sadness were induced in the appropriate conditions, Experiment 2 indicated that writing about a sad experience also induced disgust, fear, and anger, compared to writing about a happy experience. Possible resolutions to avoid the limitations of the AEMT to induce specific discrete emotions are discussed. PMID:24776697

  14. On the Validity of the Autobiographical Emotional Memory Task for Emotion Induction

    PubMed Central

    Mills, Caitlin; D'Mello, Sidney

    2014-01-01

    The Autobiographical Emotional Memory Task (AEMT), which involves recalling and writing about intense emotional experiences, is a widely used method to experimentally induce emotions. The validity of this method depends upon the extent to which it can induce specific desired emotions (intended emotions), while not inducing any other (incidental) emotions at different levels across one (or more) conditions. A review of recent studies that used this method indicated that most studies exclusively monitor post-writing ratings of the intended emotions, without assessing the possibility that the method may have differentially induced other incidental emotions as well. We investigated the extent of this issue by collecting both pre- and post-writing ratings of incidental emotions in addition to the intended emotions. Using methods largely adapted from previous studies, participants were assigned to write about a profound experience of anger or fear (Experiment 1) or happiness or sadness (Experiment 2). In line with previous research, results indicated that intended emotions (anger and fear) were successfully induced in the respective conditions in Experiment 1. However, disgust and sadness were also induced while writing about an angry experience compared to a fearful experience. Similarly, although happiness and sadness were induced in the appropriate conditions, Experiment 2 indicated that writing about a sad experience also induced disgust, fear, and anger, compared to writing about a happy experience. Possible resolutions to avoid the limitations of the AEMT to induce specific discrete emotions are discussed. PMID:24776697

  15. On the validity of the autobiographical emotional memory task for emotion induction.

    PubMed

    Mills, Caitlin; D'Mello, Sidney

    2014-01-01

    The Autobiographical Emotional Memory Task (AEMT), which involves recalling and writing about intense emotional experiences, is a widely used method to experimentally induce emotions. The validity of this method depends upon the extent to which it can induce specific desired emotions (intended emotions), while not inducing any other (incidental) emotions at different levels across one (or more) conditions. A review of recent studies that used this method indicated that most studies exclusively monitor post-writing ratings of the intended emotions, without assessing the possibility that the method may have differentially induced other incidental emotions as well. We investigated the extent of this issue by collecting both pre- and post-writing ratings of incidental emotions in addition to the intended emotions. Using methods largely adapted from previous studies, participants were assigned to write about a profound experience of anger or fear (Experiment 1) or happiness or sadness (Experiment 2). In line with previous research, results indicated that intended emotions (anger and fear) were successfully induced in the respective conditions in Experiment 1. However, disgust and sadness were also induced while writing about an angry experience compared to a fearful experience. Similarly, although happiness and sadness were induced in the appropriate conditions, Experiment 2 indicated that writing about a sad experience also induced disgust, fear, and anger, compared to writing about a happy experience. Possible resolutions to avoid the limitations of the AEMT to induce specific discrete emotions are discussed.

  16. Alleviation of interferences and reduction of sample memory in inductively coupled plasma mass spectrometry

    SciTech Connect

    Smith, F.G.

    1991-06-27

    A simple variation sample preparation and introduction allows the measurement of chlorine isotope ratios by inductively coupled plasma mass spectroscopy (ICP-MS). Dissolution of the sample in D{sub 2}O rather than H{sub 2}O attenuates the major polyatomic ion {sup 36}ArH{sup +} and frees m/z = 37 for determination of {sup 37}Cl{sup +}. The isotope ratio {sup 35}Cl/{sup 37}Cl in a 50 mg L{sup {minus}1} solution of Cl as LiCl is determined with a relative standard deviation (RDS) of 0.21%. A method for the determination of boron is a variety of biological samples is described. Sample material is fused with Na{sub 2}CO{sub 3} and boron is separated from matrix components by using Amberlite IRA-743 boron selective ion-exchange resin. Boron is eluted with 1% HNO{sub 3} and samples are introduced to an ICP-mass spectrometer with a direct injection nebulizer (DIN). Xenon is added at 10 or 37 mL min{sup {minus}1} to the aerosol gas flow of an argon ICP-mass spectrometer. Addition of Xe substantially reduces polyatomic ions such as N{sub 2}{sup +}, HN{sub 2}{sup +}, NO{sup +}, ArH{sup +}, ClO{sup +}, ArC{sup +}, ClOH{sup +}, ArN{sup +}, and ArO{sup +} and facilitates the measurement of Si, K, V, Cr, and Fe. Isotope ratios are determined with RSDs from 0.6% to 1.6%. 210 refs., 14 figs., 19 tabs.

  17. Lenalidomide Polarizes Th1-specific Anti-tumor Immune Response and Expands XBP1 Antigen-Specific Central Memory CD3+CD8+ T cells against Various Solid Tumors

    PubMed Central

    Bae, Jooeun; Keskin, Derin B; Cowens, Kristen; Lee, Ann-Hwee; Dranoff, Glen; Munshi, Nikhil C; Anderson, Kenneth C

    2016-01-01

    Introduction Effective combination immunotherapeutic strategies may be required to enhance effector cells’ anti-tumor activities and improve clinical outcomes. Methods XBP1 antigen-specific cytotoxic T lymphocytes (XBP1-CTL) generated using immunogenic heteroclitic XBP1 US184-192 (YISPWILAV) and XBP1 SP367-375 (YLFPQLISV) peptides or various solid tumor cells over-expressing XBP1 target antigen were evaluated, either alone or in combination with lenalidomide, for phenotype and immune functional activity. Results Lenalidomide treatment of XBP1-CTL increased the proportion of CD45RO+ memory CD3+CD8+ T cells, but not the total CD3+CD8+ T cells. Lenalidomide upregulated critical T cell activation markers and costimulatory molecules (CD28, CD38, CD40L, CD69, ICOS), especially within the central memory CTL subset of XBP1-CTL, while decreasing TCRαβ and T cell checkpoint blockade (CTLA-4, PD-1). Lenalidomide increased the anti-tumor activities of XBP1-CTL memory subsets, which were associated with expression of Th1 transcriptional regulators (T-bet, Eomes) and Akt activation, thereby resulting in enhanced IFN-γ production, granzyme B upregulation and specific CD28/CD38-positive and CTLA-4/PD-1-negative cell proliferation. Conclusions These studies suggest the potential benefit of lenalidomide treatment to boost anti-tumor activities of XBP1-specific CTL against a variety of solid tumors and enhance response to an XBP1-directing cancer vaccine regime.

  18. Dicer Regulates the Balance of Short-Lived Effector and Long-Lived Memory CD8 T Cell Lineages

    PubMed Central

    Baumann, Florian M.; Yuzefpolskiy, Yevgeniy; Sarkar, Surojit; Kalia, Vandana

    2016-01-01

    MicroRNAs constitute a major post-transcriptional mechanism for controlling protein expression, and are emerging as key regulators during T cell development and function. Recent reports of augmented CD8 T cell activation and effector differentiation, and aberrant migratory properties upon ablation of Dicer/miRNAs in naïve cells have established a regulatory role of miRNAs during priming. Whether miRNAs continue to exert similar functions or are dispensable during later stages of CD8 T cell expansion and memory differentiation remains unclear. Here, we report a critical role of Dicer/miRNAs in regulating the balance of long-lived memory and short-lived terminal effector fates during the post-priming stages when CD8 T cells undergo clonal expansion to generate a large cytotoxic T lymphocyte (CTL) pool and subsequently differentiate into a quiescent memory state. Conditional ablation of Dicer/miRNAs in early effector CD8 T cells following optimal activation and expression of granzyme B, using unique dicerfl/fl gzmb-cre mice, led to a strikingly diminished peak effector size relative to wild-type antigen-specific cells in the same infectious milieu. Diminished expansion of Dicer-ablated CD8 T cells was associated with lack of sustained antigen-driven proliferation and reduced accumulation of short-lived effector cells. Additionally, Dicer-ablated CD8 T cells exhibited more pronounced contraction after pathogen clearance and comprised a significantly smaller proportion of the memory pool, despite significantly higher proportions of CD127Hi memory precursors at the effector peak. Combined with previous reports of dynamic changes in miRNA expression as CD8 T cells differentiate from naïve to effector and memory states, these findings support distinct stage-specific roles of miRNA-dependent gene regulation during CD8 T cell differentiation. PMID:27627450

  19. Dicer Regulates the Balance of Short-Lived Effector and Long-Lived Memory CD8 T Cell Lineages.

    PubMed

    Baumann, Florian M; Yuzefpolskiy, Yevgeniy; Sarkar, Surojit; Kalia, Vandana

    2016-01-01

    MicroRNAs constitute a major post-transcriptional mechanism for controlling protein expression, and are emerging as key regulators during T cell development and function. Recent reports of augmented CD8 T cell activation and effector differentiation, and aberrant migratory properties upon ablation of Dicer/miRNAs in naïve cells have established a regulatory role of miRNAs during priming. Whether miRNAs continue to exert similar functions or are dispensable during later stages of CD8 T cell expansion and memory differentiation remains unclear. Here, we report a critical role of Dicer/miRNAs in regulating the balance of long-lived memory and short-lived terminal effector fates during the post-priming stages when CD8 T cells undergo clonal expansion to generate a large cytotoxic T lymphocyte (CTL) pool and subsequently differentiate into a quiescent memory state. Conditional ablation of Dicer/miRNAs in early effector CD8 T cells following optimal activation and expression of granzyme B, using unique dicerfl/fl gzmb-cre mice, led to a strikingly diminished peak effector size relative to wild-type antigen-specific cells in the same infectious milieu. Diminished expansion of Dicer-ablated CD8 T cells was associated with lack of sustained antigen-driven proliferation and reduced accumulation of short-lived effector cells. Additionally, Dicer-ablated CD8 T cells exhibited more pronounced contraction after pathogen clearance and comprised a significantly smaller proportion of the memory pool, despite significantly higher proportions of CD127Hi memory precursors at the effector peak. Combined with previous reports of dynamic changes in miRNA expression as CD8 T cells differentiate from naïve to effector and memory states, these findings support distinct stage-specific roles of miRNA-dependent gene regulation during CD8 T cell differentiation. PMID:27627450

  20. [Induction of amnesia induced by disturbance of memory consolidation by antagonists of glutamate or serotonin receptors will be suppressed by the protein synthesis inhibitor].

    PubMed

    Solntseva, S V; Nikitin, V P

    2010-12-01

    We have previously found two stages of amnesia evoked by disruption of memory reconsolidation with MK-801 (NMDA glutamate receptors antagonists) application in food aversion conditioned snails. Repeated conditioning restored the food aversion at early stage of amnesia development (<10 days), whereas repeated conditioning 10 days after MK-801 application did not restore the food aversion. In present work, amnesia was induced with MK-801/reminding 24 hours after food aversion conditioning, and antiamnestic effects of NMDA receptor glycine site agonist d-cycloserine were studied at early (3rd day) or late (12th day) stages of amnesia development. D-cycloserine injection and reminding restored memory only 3 days after amnesia induction whereas d-cycloserine injection without reminding was ineffective. D-cycloserine injection and reminding as well as repeated learning 12 days after amnesia induction were also ineffective in memory restoration. Thus, for the first time, it is revealed that NMDA receptor agonist d-cycloserine influences the memory restoration processes only at early but not the later stages of amnesia development.

  1. Artificial Induction of Associative Olfactory Memory by Optogenetic and Thermogenetic Activation of Olfactory Sensory Neurons and Octopaminergic Neurons in Drosophila Larvae

    PubMed Central

    Honda, Takato; Lee, Chi-Yu; Honjo, Ken; Furukubo-Tokunaga, Katsuo

    2016-01-01

    The larval brain of Drosophila melanogaster provides an excellent system for the study of the neurocircuitry mechanism of memory. Recent development of neurogenetic techniques in fruit flies enables manipulations of neuronal activities in freely behaving animals. This protocol describes detailed steps for artificial induction of olfactory associative memory in Drosophila larvae. In this protocol, the natural reward signal is substituted by thermogenetic activation of octopaminergic neurons in the brain. In parallel, the odor signal is substituted by optogenetic activation of a specific class of olfactory receptor neurons. Association of reward and odor stimuli is achieved with the concomitant application of blue light and heat that leads to activation of both sets of neurons in living transgenic larvae. Given its operational simplicity and robustness, this method could be utilized to further our knowledge on the neurocircuitry mechanism of memory in the fly brain. PMID:27445732

  2. Artificial Induction of Associative Olfactory Memory by Optogenetic and Thermogenetic Activation of Olfactory Sensory Neurons and Octopaminergic Neurons in Drosophila Larvae.

    PubMed

    Honda, Takato; Lee, Chi-Yu; Honjo, Ken; Furukubo-Tokunaga, Katsuo

    2016-01-01

    The larval brain of Drosophila melanogaster provides an excellent system for the study of the neurocircuitry mechanism of memory. Recent development of neurogenetic techniques in fruit flies enables manipulations of neuronal activities in freely behaving animals. This protocol describes detailed steps for artificial induction of olfactory associative memory in Drosophila larvae. In this protocol, the natural reward signal is substituted by thermogenetic activation of octopaminergic neurons in the brain. In parallel, the odor signal is substituted by optogenetic activation of a specific class of olfactory receptor neurons. Association of reward and odor stimuli is achieved with the concomitant application of blue light and heat that leads to activation of both sets of neurons in living transgenic larvae. Given its operational simplicity and robustness, this method could be utilized to further our knowledge on the neurocircuitry mechanism of memory in the fly brain. PMID:27445732

  3. Memories.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    1998-01-01

    This theme issue of the journal "Exploring" covers the topic of "memories" and describes an exhibition at San Francisco's Exploratorium that ran from May 22, 1998 through January 1999 and that contained over 40 hands-on exhibits, demonstrations, artworks, images, sounds, smells, and tastes that demonstrated and depicted the biological,…

  4. The adjuvant effect of a non-toxic mutant of heat-labile enterotoxin of Escherichia coli for the induction of measles virus-specific CTL responses after intranasal co-immunization with a synthetic peptide.

    PubMed Central

    Partidos, C D; Pizza, M; Rappuoli, R; Steward, M W

    1996-01-01

    The intranasal route has been shown to be effective for immunization. However, immunization via this route may require the use of potent and safe adjuvant. The construction of non-toxic mutants of heat labile enterotoxin of Escherichia coli (LT), which is a potent mucosal adjuvant, is a major breakthrough for the development of mucosal vaccines. In this study we have assessed the ability of an LT mutant (LTK63) to act as an adjuvant following intranasal co-immunization with a peptide corresponding to a measles virus cytotoxic T lymphocyte (CTL) epitope. LTK63 was more effective at potentiating the in vivo induction of peptide-specific and measles virus-specific CTL responses than was administration of the peptide in saline. A concentration of 10 micrograms/dose of LTK63 was found to be the most effective in potentiating the in vivo priming of peptide-specific and measles virus-specific CTL responses. These findings highlight the potential of the non-toxic mutant of LT as a safe mucosal adjuvant for use in humans. PMID:9014810

  5. Social Isolation During Adolescence Strengthens Retention of Fear Memories and Facilitates Induction of Late-Phase Long-Term Potentiation.

    PubMed

    Liu, Ji-Hong; You, Qiang-Long; Wei, Mei-Dan; Wang, Qian; Luo, Zheng-Yi; Lin, Song; Huang, Lang; Li, Shu-Ji; Li, Xiao-Wen; Gao, Tian-Ming

    2015-12-01

    Social isolation during the vulnerable period of adolescence produces emotional dysregulation that often manifests as abnormal behavior in adulthood. The enduring consequence of isolation might be caused by a weakened ability to forget unpleasant memories. However, it remains unclear whether isolation affects unpleasant memories. To address this, we used a model of associative learning to induce the fear memories and evaluated the influence of isolation mice during adolescence on the subsequent retention of fear memories and its underlying cellular mechanisms. Following adolescent social isolation, we found that mice decreased their social interaction time and had an increase in anxiety-related behavior. Interestingly, when we assessed memory retention, we found that isolated mice were unable to forget aversive memories when tested 4 weeks after the original event. Consistent with this, we observed that a single train of high-frequency stimulation (HFS) enabled a late-phase long-term potentiation (L-LTP) in the hippocampal CA1 region of isolated mice, whereas only an early-phase LTP was observed with the same stimulation in the control mice. Social isolation during adolescence also increased brain-derived neurotrophic factor (BDNF) expression in the hippocampus, and application of a tropomyosin-related kinase B (TrkB) receptor inhibitor ameliorated the facilitated L-LTP seen after isolation. Together, our results suggest that adolescent isolation may result in mental disorders during adulthood and that this may stem from an inability to forget the unpleasant memories via BDNF-mediated synaptic plasticity. These findings may give us a new strategy to prevent mental disorders caused by persistent unpleasant memories.

  6. Microneedle Array Design Determines the Induction of Protective Memory CD8+ T Cell Responses Induced by a Recombinant Live Malaria Vaccine in Mice

    PubMed Central

    Carey, John B.; Pearson, Frances E.; Vrdoljak, Anto; McGrath, Marie G.; Crean, Abina M.; Walsh, Patrick T.; Doody, Timothy; O'Mahony, Conor; Hill, Adrian V. S.; Moore, Anne C.

    2011-01-01

    Background Vaccine delivery into the skin has received renewed interest due to ease of access to the immune system and microvasculature, however the stratum corneum (SC), must be breached for successful vaccination. This has been achieved by removing the SC by abrasion or scarification or by delivering the vaccine intradermally (ID) with traditional needle-and-syringes or with long microneedle devices. Microneedle patch-based transdermal vaccine studies have predominantly focused on antibody induction by inactivated or subunit vaccines. Here, our principal aim is to determine if the design of a microneedle patch affects the CD8+ T cell responses to a malaria antigen induced by a live vaccine. Methodology and Findings Recombinant modified vaccinia virus Ankara (MVA) expressing a malaria antigen was percutaneously administered to mice using a range of silicon microneedle patches, termed ImmuPatch, that differed in microneedle height, density, patch area and total pore volume. We demonstrate that microneedle arrays that have small total pore volumes induce a significantly greater proportion of central memory T cells that vigorously expand to secondary immunization. Microneedle-mediated vaccine priming induced significantly greater T cell immunity post-boost and equivalent protection against malaria challenge compared to ID vaccination. Notably, unlike ID administration, ImmuPatch-mediated vaccination did not induce inflammatory responses at the site of immunization or in draining lymph nodes. Conclusions/Significance This study demonstrates that the design of microneedle patches significantly influences the magnitude and memory of vaccine-induced CD8+ T cell responses and can be optimised for the induction of desired immune responses. Furthermore, ImmuPatch-mediated delivery may be of benefit to reducing unwanted vaccine reactogenicity. In addition to the advantages of low cost and lack of pain, the development of optimised microneedle array designs for the induction

  7. Cratylia mollis 1, 4 lectin: a new biotechnological tool in IL-6, IL-17A, IL-22, and IL-23 induction and generation of immunological memory.

    PubMed

    de Oliveira, Priscilla Stela Santana; Rêgo, Moacyr Jesus Barreto de Melo; da Silva, Rafael Ramos; Cavalcanti, Mariana Brayner; Galdino, Suely Lins; Correia, Maria Tereza dos Santos; Coelho, Luana Cassandra Breitenbach Barroso; Pitta, Maira Galdino da Rocha

    2013-01-01

    Cratylia mollis lectin has already established cytokine induction in Th1 and Th2 pathways. Thereby, this study aimed to evaluate Cramoll 1, 4 in IL-6, IL-17A, IL-22, and IL-23 induction as well as analyze immunologic memory mechanism by reinducing lymphocyte stimulation. Initially we performed a screening in cultured splenocytes where Cramoll 1, 4 stimulated IL-6 production 5x more than ConA (P < 0.05). The same behavior was observed with IL-22 where the increase was greater than 4x. Nevertheless, IL-17A induction was similar for both lectins. In PBMCs, the same splenocytes course was observed for IL-6 and IL-17A. Concerning the stimulation of IL-22 and IL-23 Cramoll 1, 4 was more efficient than ConA in cytokines stimulation mainly in IL-23 (P < 0.01). Analyzing reinduced lymphocyte stimulation, IL-17A production was higher (P < 0.001) when the first stimulus was realized with Cramoll 1, 4 at 1 μ g/mL and the second at 5 μ g/mL. IL-22 shows significant differences (P < 0.01) at the same condition. Nevertheless, IL-23 revels the best response when the first stimuli was realized with Cramoll1, 4 at 100 ng/mL and the second with 5 μ g/mL. We conclude that the Cramoll 1, 4 is able to induce IL-6, IL-17A, IL-22, and IL-23 cytokines in vitro better than Concavalin A, besides immunologic memory generation, being a potential biotechnological tool in Th17 pathway studies. PMID:23586026

  8. The lung vascular filter as a site of immune induction for T cell responses to large embolic antigen.

    PubMed

    Willart, Monique A M; Jan de Heer, Hendrik; Hammad, Hamida; Soullié, Thomas; Deswarte, Kim; Clausen, Björn E; Boon, Louis; Hoogsteden, Henk C; Lambrecht, Bart N

    2009-11-23

    The bloodstream is an important route of dissemination of invading pathogens. Most of the small bloodborne pathogens, like bacteria or viruses, are filtered by the spleen or liver sinusoids and presented to the immune system by dendritic cells (DCs) that probe these filters for the presence of foreign antigen (Ag). However, larger pathogens, like helminths or infectious emboli, that exceed 20 microm are mostly trapped in the vasculature of the lung. To determine if Ag trapped here can be presented to cells of the immune system, we used a model of venous embolism of large particulate Ag (in the form of ovalbumin [OVA]-coated Sepharose beads) in the lung vascular bed. We found that large Ags were presented and cross-presented to CD4 and CD8 T cells in the mediastinal lymph nodes (LNs) but not in the spleen or liver-draining LNs. Dividing T cells returned to the lungs, and a short-lived infiltrate consisting of T cells and DCs formed around trapped Ag. This infiltrate was increased when the Toll-like receptor 4 was stimulated and full DC maturation was induced by CD40 triggering. Under these conditions, OVA-specific cytotoxic T lymphocyte responses, as well as humoral immunity, were induced. The T cell response to embolic Ag was severely reduced in mice depleted of CD11c(hi) cells or Ly6C/G(+) cells but restored upon adoptive transfer of Ly6C(hi) monocytes. We conclude that the lung vascular filter represents a largely unexplored site of immune induction that traps large bloodborne Ags for presentation by monocyte-derived DCs.

  9. The p60 and NamA Autolysins from Listeria monocytogenes Contribute to Host Colonization and Induction of Protective Memory

    PubMed Central

    Chandrabos, Ceena; Soudja, Saïdi M’Homa; Weinrick, Brian; Gros, Marilyn; Frangaj, Aurel; Rahmoun, Massilva; Jacobs, William R.; Lauvau, Grégoire

    2014-01-01

    Inducing long-term protective memory CD8+ T cells is a desirable goal for vaccines against intracellular pathogens. However, the mechanisms of differentiation of CD8+ T cells into long-lived memory cells capable of mediating protection of immunized hosts remain incompletely understood. We have developed an experimental system using mice immunized with WT or mutants of the intracellular bacterium Listeria monocytogenes (Lm) that either do or do not develop protective memory CD8+ T cells. We previously reported that mice immunized with Lm lacking functional SecA2, an auxiliary secretion system of gram-positive bacteria, did not differentiate functional memory CD8+ T cells that protected against a challenge infection with WT Lm. Herein we hypothesized that the p60 and NamA autolysins of Lm, which are major substrates of the SecA2 pathway, account for this phenotype. We generated Lm genetically deficient for genes encoding for the p60 and NamA proteins, ΔiapΔmurA Lm, and further characterized this mutant. Δp60ΔNamA Lm exhibited a strong filamentous phenotype, inefficiently colonized host tissues, and grew mostly outside cells. When Δp60ΔNamA Lm was made single unit (SU), cell invasion was restored to WT levels during vaccination, yet induced memory T cells still did not protect immunized hosts against recall infection. Recruitment of blood phagocytes and antigen-presenting cell activation was close to that of mice immunized with ΔActA Lm which develop protective memory. However, key inflammatory factors involved in optimal T cell-programming such as IL-12 and type I IFN (IFN-I) were lacking, suggesting that cytokine signals may largely account for the observed phenotype. Thus altogether, these results establish that p60 and NamA secreted by Lm promote primary host cell-invasion, the inflammatory response and the differentiation of functional memory CD8+ T cells, by preventing Lm filamentation during growth and subsequent triggering of innate sensing mechanisms

  10. Induction of memory cytotoxic T cells to influenza A virus and subsequent viral clearance is not modulated by PB1-F2-dependent inflammasome activation

    PubMed Central

    Lee, Patricia (Hoi Yee); Bird, Nicola; MacKenzie-Kludas, Charley; Mansell, Ashley; Kedzierska, Katherine; Brown, Lorena; McAuley, Julie

    2016-01-01

    Expression of the viral virulence protein PB1-F2 during infection has been linked to NLRP3 inflammasome complex activation in macrophages and induction of early inflammatory events enhancing immunopathology during influenza disease. We sought to determine whether PB1-F2-specific NLRP3 inflammasome activation influenced the magnitude and/or robustness of the CD8+ T-cell responses specific for conserved viral antigens and subsequent virus elimination. Using murine heterosubtypic viral infection models, we showed that mice infected with virus unable to produce PB1-F2 protein showed no deficit in the overall magnitude and functional memory responses of CD8+ T cells established during the effector phase compared with those infected with wild-type PB1-F2-expressing virus and were equally capable of mounting robust recall responses. These data indicate that while expression of PB1-F2 protein can induce inflammatory events, the capacity to generate memory CD8+ T cells specific for immunodominant viral epitopes remains uncompromised. PMID:26667784

  11. Induction of Memory Deficit in Mice with Chronic Exposure to Cerebrospinal Fluid from Patients with Anti-N-Methyl-D-Aspartate Receptor Encephalitis.

    PubMed

    Li, Yongzhi; Tanaka, Keiko; Wang, Li; Ishigaki, Yasuhito; Kato, Nobuo

    2015-01-01

    Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is now widely recognized and the patients with this disease show prominent psychiatric symptoms followed by seizures, respiratory failure, involuntary movement, autonomic instability, and amnesia. The anti-NMDAR antibody titer coincides with disease activity, and antibody-deprivation treatment ameliorates neurological symptoms. Previous studies have shown that clusters of NMDARs on the neuronal surface decrease in density upon incubation with the cerebrospinal fluid from patients (NMDAR-CSF), and that the induction of long-term potentiation, a cellular mechanism underlie learning and memory processes, was suppressed with NMDAR-CSF. In this study, we exposed mice to NMDAR-CSF in an attempt to reproduce the human symptoms in mice. CSF was continuously administered via a cannula placed in the lateral ventricle of the mouse that connected to an osmotic pump transplanted in the back of the mouse. From day 8-18, we evaluated the behavior of the mice using standardized tests that were performed serially. Mice exposed to NMDAR-CSF showed impaired spatial memory, as detected with the Morris water maze test. Brain tissue from mice with memory disturbances had decreased content of NMDAR protein in the hippocampal area shown by immunohistochemistry, which is consistent with the anti-NMDAR antibodies affect the expression and function of NMDARs, resulting in anti-NMDAR encephalitis-like symptoms. Also, the mice treated with the NMDAR-CSF did not show inflammatory cell infiltration or neuron loss in their brain tissue and this lack of nervous tissue destruction is encouraging as it is consistent with the idea that this disease can be treated through immunotherapy.

  12. Frequency analysis of simian virus 40-specific cytotoxic T lymphocyte precursors in the high responder C57BL/6 mouse strain.

    PubMed

    Jennings, S R; Fresa, K L; Lippe, P A; Milici, J E; Tevethia, S S

    1988-10-01

    Studies in this laboratory have shown that long term simian virus 40 (SV40)-specific cytolytic T lymphocyte (CTL) cultures established from the spleens of high responder C57BL/6 (B6; H-2b) mice exhibit a preference for the selection of H-2Db-restricted CTL clones. In this study, we have investigated the basis for this selection. Limiting dilution cultures were established using responder cells from the popliteal lymph nodes and the spleens of B6 mice immunized subcutaneously in the hind footpads or via the intraperitoneal route, respectively, with syngeneic SV40-transformed cells expressing a full length (1 to 708 amino acid residues) SV40 large T antigen. The relative frequency of CTL precursors (CTLp) able to expand in vitro in the presence of SV40-transformed stimulator cells and interleukin 2 and exhibit lytic activity against H-2b cells expressing full length T antigen ranged from 1/1900 to 1/15,000 in the popliteal lymph node and from 1/8000 to 1/55,000 in the spleen. In these two experimental systems, CTLp restricted to H-2Kb were apparently present at higher frequency than H-2Db-restricted CTLp. Furthermore, CTLp recognizing determinants within the amino-terminal or carboxy-terminal halves of T antigen were generated in approximately equal numbers. The relative affinity of SV40-specific CTL, assessed by inhibition with anti-Lyt 2 monoclonal antibody, indicated that CTL restricted to H-2Db interacted with their target with greater affinity than CTL restricted to H-2Kb. These data suggest that the predominance of isolation of H-2Db-restricted CTL clones from long term in vitro cultures may be a function of the relative affinity of this population as a whole, rather than due to the immunodominance of this subpopulation during the in vivo response to SV40 T antigen. PMID:2459302

  13. A Subset of Latency-Reversing Agents Expose HIV-Infected Resting CD4+ T-Cells to Recognition by Cytotoxic T-Lymphocytes

    PubMed Central

    Jones, R. Brad; Mueller, Stefanie; O’Connor, Rachel; Rimpel, Katherine; Sloan, Derek D.; Karel, Dan; Wong, Hing C.; Jeng, Emily K.; Thomas, Allison S.; Whitney, James B.; Lim, So-Yon; Kovacs, Colin; Benko, Erika; Karandish, Sara; Huang, Szu-Han; Buzon, Maria J.; Lichterfeld, Mathias; Irrinki, Alivelu; Murry, Jeffrey P.; Tsai, Angela; Yu, Helen; Geleziunas, Romas; Trocha, Alicja; Ostrowski, Mario A.; Irvine, Darrell J.; Walker, Bruce D.

    2016-01-01

    Resting CD4+ T-cells harboring inducible HIV proviruses are a critical reservoir in antiretroviral therapy (ART)-treated subjects. These cells express little to no viral protein, and thus neither die by viral cytopathic effects, nor are efficiently cleared by immune effectors. Elimination of this reservoir is theoretically possible by combining latency-reversing agents (LRAs) with immune effectors, such as CD8+ T-cells. However, the relative efficacy of different LRAs in sensitizing latently-infected cells for recognition by HIV-specific CD8+ T-cells has not been determined. To address this, we developed an assay that utilizes HIV-specific CD8+ T-cell clones as biosensors for HIV antigen expression. By testing multiple CD8+ T-cell clones against a primary cell model of HIV latency, we identified several single agents that primed latently-infected cells for CD8+ T-cell recognition, including IL-2, IL-15, two IL-15 superagonists (IL-15SA and ALT-803), prostratin, and the TLR-2 ligand Pam3CSK4. In contrast, we did not observe CD8+ T-cell recognition of target cells following treatment with histone deacetylase inhibitors or with hexamethylene bisacetamide (HMBA). In further experiments we demonstrate that a clinically achievable concentration of the IL-15 superagonist ‘ALT-803’, an agent presently in clinical trials for solid and hematological tumors, primes the natural ex vivo reservoir for CD8+ T-cell recognition. Thus, our results establish a novel experimental approach for comparative evaluation of LRAs, and highlight ALT-803 as an LRA with the potential to synergize with CD8+ T-cells in HIV eradication strategies. PMID:27082643

  14. IDO and regulatory T cell support are critical for cytotoxic T lymphocyte-associated Ag-4 Ig-mediated long-term solid organ allograft survival.

    PubMed

    Sucher, Robert; Fischler, Klaus; Oberhuber, Rupert; Kronberger, Irmgard; Margreiter, Christian; Ollinger, Robert; Schneeberger, Stefan; Fuchs, Dietmar; Werner, Ernst R; Watschinger, Katrin; Zelger, Bettina; Tellides, George; Pilat, Nina; Pratschke, Johann; Margreiter, Raimund; Wekerle, Thomas; Brandacher, Gerald

    2012-01-01

    Costimulatory blockade of CD28-B7 interaction with CTLA4Ig is a well-established strategy to induce transplantation tolerance. Although previous in vitro studies suggest that CTLA4Ig upregulates expression of the immunoregulatory enzyme IDO in dendritic cells, the relationship of CTLA4Ig and IDO in in vivo organ transplantation remains unclear. In this study, we studied whether concerted immunomodulation in vivo by CTLA4Ig depends on IDO. C57BL/6 recipients receiving a fully MHC-mismatched BALB/c heart graft treated with CTLA4Ig + donor-specific transfusion showed indefinite graft survival (>100 d) without signs of chronic rejection or donor specific Ab formation. Recipients with long-term surviving grafts had significantly higher systemic IDO activity as compared with rejectors, which markedly correlated with intragraft IDO and Foxp3 levels. IDO inhibition with 1-methyl-dl-tryptophan, either at transplant or at postoperative day 50, abrogated CTLA4Ig + DST-induced long-term graft survival. Importantly, IDO1 knockout recipients experienced acute rejection and graft survival comparable to controls. In addition, αCD25 mAb-mediated depletion of regulatory T cells (Tregs) resulted in decreased IDO activity and again prevented CTLA4Ig + DST induced indefinite graft survival. Our results suggest that CTLA4Ig-induced tolerance to murine cardiac allografts is critically dependent on synergistic cross-linked interplay of IDO and Tregs. These results have important implications for the clinical development of this costimulatory blocker.

  15. Residues outside of the HLA-A2 peptide-binding groove can abrogate or enhance recognition of influenza virus matrix peptide pulsed cells by cytotoxic T lymphocytes.

    PubMed

    Teng, J M; Hogan, K T

    1994-04-01

    An examination of the crystal structure of HLA-A2.1 reveals two classes of residues on the class I MHC molecule that could affect CTL recognition: (1) those predicted to interact with the TCR directly; and (2) those that interact with bound peptides. To examine the role of individual TCR contacting residues, as well as residues not predicted to interact with bound peptide or the TCR, a panel of 28 HLA-A2 variants that differ from each other by a single amino acid substitution in either the alpha 1- or alpha 2-domain was utilized. Peptide titration, time course and cold target inhibition analysis of these targets showed that only the substitution of position 62 in the alpha 1-domain had a significant effect on recognition of the MHC-peptide complex by influenza matrix protein M1 (57-68) peptide-specific, HLA-A2.1-restricted CTL. In contrast, substitutions at positions 154, 162 and 163 in the alpha 2-domain abolished recognition by the same CTL. Additionally, substitutions at position 138 in the alpha 2-domain and positions 107 and 127 on the loops connecting the beta-strand in the alpha 2-domain were recognized in a more efficient, heteroclitic fashion. Overall, there was no direct correlation between the level of peptide binding to the variants and the level of T cell recognition of the variants. These results indicate that residues in the alpha 2-domain may be more important than residues in the alpha 1-domain in controlling TCR binding to the class I MHC molecule and suggest that the "footprint" of the TCR may be more extensive than previously predicted and encompass a broad region that extends beyond the alpha 2-helix. These findings also imply that the class I MHC molecule may exist in a "tipped" orientation on the cell surface during T cell recognition.

  16. Both major and minor peptide-binding pockets in HLA-A2 influence the presentation of influenza virus matrix peptide to cytotoxic T lymphocytes.

    PubMed

    Teng, J M; Hogan, K T

    1994-04-01

    Most of the polymorphic residues in class I MHC molecules are concentrated in the alpha 1- and alpha 2-domains with their side chains pointing towards the antigen peptide site. Previous crystal structure analysis revealed six pockets inside the peptide-binding groove and the "extra" electron density in some of the pockets indicated that the pockets are involved in direct peptide binding. In order to investigate the functional role of individual positions from each pocket in antigen presentation, 37 HLA-A2 variants with single amino acid substitution in the peptide-binding groove were generated and used to analyse the specificity of influenza A virus matrix peptide-specific, HLA-A2-restricted CTL. The ability to present peptide by each variant was studied in detail by peptide titration, cold target inhibition, time course and limiting dilution analysis. The direct effect on peptide binding by these substitutions was determined by cell surface class I MHC molecule reconstitution analysis. The results demonstrated that each of the six peptide binding pockets plays a role in T cell recognition. Substitutions introduced into pocket F had less effect on CTL recognition than substitutions introduced in other pockets. With the exception of Tyr substitution for Phe9, single amino acid substitutions in the peptide-binding groove had only minor effects on peptide binding. Therefore, the impact of the substitutions in altering the epitopes recognized by CTL seems to be mediated through an alteration in the conformation of the bound peptide.

  17. Transfer of Maternal Immune Cells by Breastfeeding: Maternal Cytotoxic T Lymphocytes Present in Breast Milk Localize in the Peyer’s Patches of the Nursed Infant

    PubMed Central

    Tang, May; Zumba, Osvaldo; Mehta, Hetali; Toma, Annmarie; Sant’Angelo, Derek; Laouar, Yasmina

    2016-01-01

    Despite our knowledge of the protective role of antibodies passed to infants through breast milk, our understanding of immunity transfer via maternal leukocytes is still limited. To emulate the immunological interface between the mother and her infant while breast-feeding, we used murine pups fostered after birth onto MHC-matched and MHC-mismatched dams. Overall, data revealed that: 1) Survival of breast milk leukocytes in suckling infants is possible, but not significant after the foster-nursing ceases; 2) Most breast milk lymphocytes establish themselves in specific areas of the intestine termed Peyer’s patches (PPs); 3) While most leukocytes in the milk bolus were myeloid cells, the majority of breast milk leukocytes localized to PPs were T lymphocytes, and cytotoxic T cells (CTLs) in particular; 4) These CTLs exhibit high levels of the gut-homing molecules α4β7 and CCR9, but a reduced expression of the systemic homing marker CD62L; 5) Under the same activation conditions, transferred CD8 T cells through breast milk have a superior capacity to produce potent cytolytic and inflammatory mediators when compared to those generated by the breastfed infant. It is therefore possible that maternal CTLs found in breast milk are directed to the PPs to compensate for the immature adaptive immune system of the infant in order to protect it against constant oral infectious risks during the postnatal phase. PMID:27285085

  18. Aberrant Glycosylation of Anchor-Optimized MUC1 Peptides Can Enhance Antigen Binding Affinity and Reverse Tolerance to Cytotoxic T Lymphocytes

    PubMed Central

    Pathangey, Latha B.; Lakshminarayanan, Vani; Suman, Vera J.; Pockaj, Barbara A.; Mukherjee, Pinku; Gendler, Sandra J.

    2016-01-01

    Cancer vaccines have often failed to live up to their promise, although recent results with checkpoint inhibitors are reviving hopes that they will soon fulfill their promise. Although mutation-specific vaccines are under development, there is still high interest in an off-the-shelf vaccine to a ubiquitous antigen, such as MUC1, which is aberrantly expressed on most solid and many hematological tumors, including more than 90% of breast carcinomas. Clinical trials for MUC1 have shown variable success, likely because of immunological tolerance to a self-antigen and to poor immunogenicity of tandem repeat peptides. We hypothesized that MUC1 peptides could be optimized, relying on heteroclitic optimizations of potential anchor amino acids with and without tumor-specific glycosylation of the peptides. We have identified novel MUC1 class I peptides that bind to HLA-A*0201 molecules with significantly higher affinity and function than the native MUC1 peptides. These peptides elicited CTLs from normal donors, as well as breast cancer patients, which were highly effective in killing MUC1-expressing MCF-7 breast cancer cells. Each peptide elicited lytic responses in greater than 6/8 of normal individuals and 3/3 breast cancer patients. The CTLs generated against the glycosylated-anchor modified peptides cross reacted with the native MUC1 peptide, STAPPVHNV, suggesting these analog peptides may offer substantial improvement in the design of epitope-based vaccines. PMID:27367740

  19. Personalized Kampo Medicine Facilitated Both Cytotoxic T Lymphocyte Response and Clinical Benefits Induced by Personalized Peptide Vaccination for Advanced Esophageal Cancer

    PubMed Central

    Yutani, Shigeru; Shichijo, Shigeki; Sakamoto, Shinjiro; Naito, Masayasu; Okuda, Koji; Morita, Michi; Yamaguchi, Rin; Itoh, Kyogo

    2016-01-01

    We retrospectively evaluated if personalized Kampo medicine (PKM) could facilitate CTL responses and clinical benefits induced by personalized peptide vaccination (PPV), in which HLA-matched vaccines were selected and administered based on the preexisting host immunity, for advanced esophageal cancer (aEC) patients. Among 34 aEC patients entered in the clinical study, 23 patients received PKM and PPV without (n = 12) or with chemotherapy (n = 11), while the remaining 11 patients did not receive PKM but received PPV without (n = 6) or with chemotherapy (n = 5), respectively. Incidence of adverse events was significantly lower or higher in PKM and PPV arm (n = 23) or PPV and chemotherapy arm (n = 16) as compared to that of the counter arm (n = 11 or 18), respectively. Postvaccination PBMCs from the patients undergoing PKM and PPV showed significantly higher CTL responses as compared to the counter arm. The median progression-free survival (PFS) or median survival time (MST) of 34 patients was 2.9 or 7.6 months, respectively. The combination therapy in PPV and PKM arm, but not that in PPV and chemotherapy arm, significantly (P = 0.02) prolonged MST. These results could warrant a next step of prospective clinical study of PKM and PPV for aEC patients. PMID:27703488

  20. The Role of NKG2D Signaling in Inhibition of Cytotoxic T-Lymphocyte Lysis by the Murine Cytomegalovirus Immunoevasin m152/gp40▿

    PubMed Central

    Pinto, Amelia K.; Jamieson, Amanda M.; Raulet, David H.; Hill, Ann B.

    2007-01-01

    Three proteins encoded by murine cytomegalovirus (MCMV)— gp34, encoded by m04 (m04/gp34), gp48, encoded by m06 (m06/gp48), and gp40, encoded by m152 (m152/gp40)—act together to powerfully impact the ability of primed cytotoxic CD8 T lymphocytes (CTL) to kill virus-infected cells. Of these three, the impact of m152/gp40 on CTL lysis appears greater than would be expected based on its impact on cell surface major histocompatibility complex (MHC) class I. In addition to MHC class I, m152/gp40 also downregulates the RAE-1 family of NKG2D ligands, which can provide costimulation for CD8 T cells. We hypothesized that m152/gp40 may impact CTL lysis so profoundly because it inhibits both antigen presentation and NKG2D-mediated costimulation. We therefore tested the extent to which m152/gp40's ability to inhibit CTL lysis of MCMV-infected cells could be accounted for by its inhibition of NKG2D signaling. As was predictable from the results reported in the literature, NKG2D ligands were not detected by NKG2D tetramer staining of cells infected with wild-type MCMV, whereas those infected with MCMV lacking m152/gp40 displayed measurable levels of the NKG2D ligand. To determine whether NKG2D signaling contributed to the ability of CTL to lyse these cells, we used a blocking anti-NKG2D antibody. Blocking NKG2D signaling did affect the killing of MCMV-infected cells for some epitopes. However, for all epitopes, the impact of m152/gp40 on CTL lysis was much greater than the impact of inhibition of NKG2D signaling. We conclude that the downregulation of NKG2D ligands by MCMV makes only a small contribution to the impact of m152/gp40 on CTL lysis and only for a small subset of CTL. PMID:17855532

  1. K562-Derived Whole-Cell Vaccine Enhances Antitumor Responses of CAR-Redirected Virus-Specific Cytotoxic-T Lymphocytes in vivo

    PubMed Central

    Caruana, Ignazio; Weber, Gerrit; Ballard, Brandon Corde’; Wood, Michael Scott; Savoldo, Barbara; Dotti, Gianpietro

    2015-01-01

    Purpose Adoptive transfer of Epstein Barr Virus (EBV)- and Cytomegalovirus (CMV)-specific cytotoxic T cells (CTLs) genetically modified to express a Chimeric Antigen Receptor (CAR) induces objective tumor responses in clinical trials. In vivo expansion and persistence of these cells is crucial to achieve sustained clinical responses. We aimed to develop an off-the-shelf whole-cell vaccine to boost CAR-redirected virus-specific CTLs in vivo after adoptive transfer. As proof of principle, we validated our vaccine approach by boosting CMV-specific CTLs (CMV-CTLs) engineered with a CAR that targets the GD2 antigen. Experimental Design We generated the whole-cell vaccine by engineering the K562 cell line to express the CMV-pp65 protein and the immune stimulatory molecules CD40L and OX40L. Single-cell-derived clones were used to stimulate CMV-CTLs in vitro and in vivo in a xenograft model. We also assessed whether the in vivo boosting of CAR-redirected CMV-CTLs with the whole-cell vaccine enhances the antitumor responses. Finally, we addressed potential safety concerns by including the inducible safety switch caspase9 (iC9) gene in the whole-cell vaccine. Results We found that K562 expressing CMV-pp65, CD40L and OX40L effectively stimulates CMV-specific responses in vitro by promoting antigen cross-presentation to professional antigen-presenting cells (APCs). Vaccination also enhances antitumor effects of CAR-redirected CMV-CTLs in xenograft tumor models. Activation of the iC9 gene successfully induces growth arrest of engineered K562 implanted in mice. Conclusions Vaccination with a whole-cell vaccine obtained from K562 engineered to express CMV-pp65, CD40L, OX40L and iC9 can safely enhance the antitumor effects of CAR-redirected CMV-CTLs. PMID:25691731

  2. Interaction of Toll-Like Receptors with the Molecular Chaperone Gp96 Is Essential for Its Activation of Cytotoxic T Lymphocyte Response

    PubMed Central

    Liu, Weiwei; Chen, Mi; Li, Xinghui; Zhao, Bao; Hou, Junwei; Zheng, Huaguo; Qiu, Lipeng; Li, Zihai; Meng, Songdong

    2016-01-01

    The heat shock protein gp96 elicits specific T cell responses to its chaperoned peptides against cancer and infectious diseases in both rodent models and clinical trials. Although gp96-induced innate immunity, via a subset of Toll like receptors (TLRs), and adaptive immunity, through antigen presentation, are both believed to be important for priming potent T cell responses, direct evidence for the role of gp96-mediated TLR activation related to its functional T cell activation is lacking. Here, we report that gp96 containing mutations in its TLR-binding domain failed to activate macrophages, but peptide presentation was unaffected. Moreover, we found that peptide-specific T cell responses, as well as antitumor T cell immunity induced by gp96, are severely impaired when the TLR-binding domain is mutated. These data demonstrate the essential role of the gp96-TLR interaction in priming T cell immunity and provide further molecular basis for the coupling of gp96-mediated innate with adaptive immunity. PMID:27183126

  3. A panel of unique HLA-A2 mutant molecules define epitopes recognized by HLA-A2-specific antibodies and cytotoxic T lymphocytes.

    PubMed

    Hogan, K T; Clayberger, C; Bernhard, E J; Walk, S F; Ridge, J P; Parham, P; Krensky, A M; Engelhard, V H

    1989-03-15

    HLA-A2.1 and HLA-A2.3, which differ from one another at residues 149, 152, and 156, can be distinguished by the mAb CR11-351 and many allogeneic and xenogeneic CTL. Site-directed mutagenesis was used to incorporate several different amino acid substitutions at each of these positions in HLA-A2.1 to evaluate their relative importance to serologic and CTL-defined epitopes. Recognition by mAb CR11-351 was completely lost when Thr but not Pro was substituted for Ala149. A model to explain this result based on the 3-dimensional structure of HLA-A2.1 is presented. In screening eight other mAb, only the substitutions of Pro for Val152 or Gly for Leu156 led to the loss of mAb binding. Because other non-conservative substitutions at these same positions had no effect, these results suggest that the loss of serologic epitopes is in many cases due to a more indirect effect on molecular conformation. Specificity analysis using 28 HLA-A2.1-specific alloreactive and xenoreactive CTL clones showed 19 distinct patterns of recognition. The epitopes recognized by alloreactive CTL clones demonstrated a pronounced effect by all substitutions at residue 152, including the very conservation substitution of Ala for Val. Overall, the most disruptive substitution at amino acid residue 152 was Pro, followed by Glu, Gln, and then Ala. In contrast, substitutions at 156 had little or no effect on allogeneic CTL recognition, and most clones tolerated either Gly, Ser, or Trp at this position. Similar results were seen using a panel of murine HLA-A2.1-specific CTL clones, except that substitutions at position 156 had a greater effect. The most disruptive substitution was Trp, followed by Ser and then Gly. In addition, when assessed on the entire panel of CTL, the effects of Glu and Gln substitutions at position 152 demonstrated that the introduction of a charge difference is no more disruptive than a comparable change in side chain structure that does not alter charge. Taken together, these results indicate that the effect of amino acid replacements at positions 152 and 156 on CTL-defined epitopes depends strongly on the nature of the substitution. Thus, considerable caution must be exercised in evaluating the significance of particular positions on the basis of single mutations. Nonetheless, the more extensive analysis conducted here indicates that there are differences among residues in the class I Ag "binding pocket," with residue 152 playing a relatively more important role in formation of allogeneic CTL-defined epitopes than residue 156. PMID:2466083

  4. Comparative structural analysis of HLA-A2 antigens distinguishable by cytotoxic T lymphocytes. II. Variant DK1: evidence for a discrete CTL recognition region.

    PubMed

    Krangel, M S; Biddison, W E; Strominger, J L

    1983-04-01

    Multiple amino acid sequence differences distinguish individual HLA antigens. Those residues important in immune recognition events have not been defined. Recent studies have identified HLA-A2 structural variants that, although serologically indistinguishable from other HLA-A2 antigens, are recognized poorly, if at all, by HLA-A2-restricted, influenza virus-immune, or HLA-A2-specific alloimmune CTL. In this study we utilize double-label tryptic peptide comparisons performed by both reverse-phase HPLC and cation exchange chromatography, in conjunction with conventional and microsequence analysis, to characterize the HLA-A2 heavy chains derived from variant DK1. We detect a single tryptic peptide that distinguishes DK1 HLA-A2 from the predominant HLA-A2 heavy chain species. This peptide spans residues 147 to 157 in the second heavy chain domain, and carries substitutions at positions 149, 152, and 156. Residues in this segment of the polypeptide are also altered in another HLA-A2 variant, as well as one H-2Kb mutant. Thus, this segment appears to be critical in forming determinants important in CTL recognition of class I antigens in general. On the basis of these and other results, we suggest that in contrast to recognition by alloantibodies, a discrete region of class I antigens may be crucial for CTL recognition. PMID:6601143

  5. Natural CD8{sup +}25{sup +} regulatory T cell-secreted exosomes capable of suppressing cytotoxic T lymphocyte-mediated immunity against B16 melanoma

    SciTech Connect

    Xie, Yufeng; Zhang, Xueshu; Zhao, Tuo; Li, Wei; Xiang, Jim

    2013-08-16

    Highlights: •CD8{sup +}25{sup +} regulatory T cells secrete tolerogenic exosomes. •CD8{sup +}25{sup +} regulatory T cell-derived exosomes exhibit immunosuppressive effect. •CD8{sup +}25{sup +} regulatory T cell-derived exosomes inhibit antitumor immunity. -- Abstract: Natural CD4{sup +}25{sup +} and CD8{sup +}25{sup +} regulatory T (Tr) cells have been shown to inhibit autoimmune diseases. Immune cells secrete exosomes (EXOs), which are crucial for immune regulation. However, immunomodulatory effect of natural Tr cell-secreted EXOs is unknown. In this study, we purified natural CD8{sup +}25{sup +} Tr cells from C57BL/6 mouse naive CD8{sup +} T cells, and in vitro amplified them with CD3/CD28 beads. EXOs (EXO{sub Tr}) were purified from Tr cell’s culture supernatants by differential ultracentrifugation and analyzed by electron microscopy, Western blot and flow cytometry. Our data showed that EXO{sub Tr} had a “saucer” or round shape with 50–100 nm in diameter, contained EXO-associated markers LAMP-1 and CD9, and expressed natural Tr cell markers CD25 and GITR. To assess immunomodulatory effect, we i.v. immunized C57BL/6 mice with ovalbumin (OVA)-pulsed DCs (DC{sub OVA}) plus Tr cells or EXO{sub Tr}, and then assessed OVA-specific CD8{sup +} T cell responses using PE-H-2K{sup b}/OVA tetramer and FITC-anti-CD8 antibody staining by flow cytometry and antitumor immunity in immunized mice with challenge of OVA-expressing BL6–10{sub OVA} melanoma cells. We demonstrated that DC{sub OVA}-stimulated CD8{sup +} T cell responses and protective antitumor immunity significantly dropped from 2.52% to 1.08% and 1.81% (p < 0.05), and from 8/8 to 2/8 and 5/8 mice DC{sub OVA} (p < 0.05) in immunized mice with co-injection of Tr cells and EXO{sub Tr}, respectively. Our results indicate that natural CD8{sup +}25{sup +} Tr cell-released EXOs, alike CD8{sup +}25{sup +} Tr cells, can inhibit CD8{sup +} T cell responses and antitumor immunity. Therefore, EXOs derived from natural CD4{sup +}25{sup +} and CD8{sup +}25{sup +} Tr cells may become an alternative for immunotherapy of autoimmune diseases.

  6. Reversible HLA multimers (Streptamers) for the isolation of human cytotoxic T lymphocytes functionally active against tumor- and virus-derived antigens.

    PubMed

    Neudorfer, Julia; Schmidt, Burkhard; Huster, Katharina M; Anderl, Florian; Schiemann, Matthias; Holzapfel, Gerd; Schmidt, Thomas; Germeroth, Lothar; Wagner, Hermann; Peschel, Christian; Busch, Dirk H; Bernhard, Helga

    2007-03-30

    The development of MHC/peptide multimers has facilitated the visualization and purification of antigen-specific T cells. However, the persistence of multimers leads to prolonged T cell receptor signaling and subsequently to altered T-cell function. We have recently developed a new type of MHC/peptide multimers, which can be dissociated from the T cell. Herein, we have generated and tested for the first time reversible HLA/peptide multimers, termed Streptamers, for the isolation of human T cells. The Streptamer technique demonstrates the specificity and sensitivity of conventional HLA/peptide tetramers with regards to the sorting of human T lymphocytes. This is shown for T cells directed against immunogenic peptides derived from viral and tumor-associated antigens. We show that antigen-specific cytotoxic T cells remain functionally active following Streptamer dissociation, whereas lytic function and proliferation of the T cells is impaired in the presence of conventional tetramers. These novel HLA/peptide Streptamer reagents allow the isolation of antigen-specific T cells with preserved function and, therefore, facilitate the development of adoptive T cell transfer regimens for the treatment of patients with cancer or infectious diseases. PMID:17306825

  7. Protective efficacy of a broadly cross-reactive swine influenza DNA vaccine encoding M2e, cytotoxic T lymphocyte epitope and consensus H3 hemagglutinin

    PubMed Central

    2012-01-01

    Background Pigs have been implicated as mixing reservoir for the generation of new pandemic influenza strains, control of swine influenza has both veterinary and public health significance. Unlike human influenza vaccines, strains used for commercially available swine influenza vaccines are not regularly replaced, making the vaccines provide limited protection against antigenically diverse viruses. It is therefore necessary to develop broadly protective swine influenza vaccines that are efficacious to both homologous and heterologous virus infections. In this study, two forms of DNA vaccines were constructed, one was made by fusing M2e to consensus H3HA (MHa), which represents the majority of the HA sequences of H3N2 swine influenza viruses. Another was made by fusing M2e and a conserved CTL epitope (NP147-155) to consensus H3HA (MNHa). Their protective efficacies against homologous and heterologous challenges were tested. Results BALB/c mice were immunized twice by particle-mediated epidermal delivery (gene gun) with the two DNA vaccines. It was shown that the two vaccines elicited substantial antibody responses, and MNHa induced more significant T cell-mediated immune response than MHa did. Then two H3N2 strains representative of different evolutional and antigenic clusters were used to challenge the vaccine-immunized mice (homosubtypic challenge). Results indicated that both of the DNA vaccines prevented homosubtypic virus infections completely. The vaccines’ heterologous protective efficacies were further tested by challenging with a H1N1 swine influenza virus and a reassortant 2009 pandemic strain. It was found that MNHa reduced the lung viral titers significantly in both challenge groups, histopathological observation showed obvious reduction of lung pathogenesis as compared to MHa and control groups. Conclusions The combined utility of the consensus HA and the conserved M2e and CTL epitope can confer complete and partial protection against homologous and heterologous challenges, respectively, in mouse model. This may provide a basis for the development of universal swine influenza vaccines. PMID:22738661

  8. Plasma membrane associated, virus-specific polypeptides required for the formation of target antigen complexes recognized by virus-specific cytotoxic T lymphocytes

    SciTech Connect

    Domber, E.A.

    1986-01-01

    These studies were undertaken to define some of the poxvirus-specific target antigens which are synthesized in infected cells and recognized by vaccinia virus-specific CTLs (VV-CTLs). Since vaccinia virus infected, unmanipulated target cells express numerous virus-specific antigens on the plasma membrane, attempts were made to manipulate expression of the poxvirus genome after infection so that one or a few defined virus-specified antigens were expressed on the surface of infected cells. In vitro (/sup 51/Cr)-release assays determined that viral DNA synthesis and expression of late viral proteins were not necessary to form a target cell which was fully competent for lysis by VV-CTLs. Under the conditions employed in these experiments, 90-120 minutes of viral protein synthesis were necessary to produce a competent cell for lysis by VV-CTLs. In order to further inhibit the expression of early viral proteins in infected cells, partially UV-inactivated vaccinia virus was employed to infect target cells. It was determined that L-cells infected with virus preparations which had been UV-irradiated for 90 seconds were fully competent for lysis by VV-CTLs. Cells infected with 90 second UV-irr virus expressed 3 predominant, plasma membrane associated antigens of 36-37K, 27-28K, and 19-17K. These 3 viral antigens represent the predominant membrane-associated viral antigens available for interaction with class I, major histocompatibility antigens and hence are potential target antigens for VV-CTLs.

  9. Induction of human immunodeficiency virus type-1-specific immunity with a novel gene transport unit (GTU)-MultiHIV DNA vaccine.

    PubMed

    Blazevic, Vesna; Männik, Andres; Malm, Maria; Sikut, Rein; Valtavaara, Minna; Toots, Urve; Ustav, Mart; Krohn, Kai

    2006-07-01

    A multiHIV fusion gene expressing an antigenic fusion protein composed of regulatory HIV-1 proteins Rev, Nef, and Tat, as well as Gag p17/p24 and a stretch of 11 cytotoxic T lymphocyte (CTL) epitope clusters from Pol and Env, was cloned into a novel DNA vector named the Gene Transport Unit (GTU). A mouse H-2(d)-restricted HIV-1 gp120 epitope (RGPGRAFVTI) was cloned into the fusion gene as well. In addition to the HIV- 1 genes the GTU codes for a nuclear anchoring protein (bovine papilloma virus E2), ensuring the long maintenance of the vector and a high expression level of the selected immunogens. BALB/c mice were immunized with the GTU-MultiHIV DNA construct by different routes and regimens of immunization to assess the immunogenicity of the DNA vaccine in vivo. Mice developed strong CD8(+) CTL responses to HIV-1 Env and Gag measured by an ELISPOT-IFN-gamma assay and chromium release assay. In addition, T cell responses to regulatory proteins Rev, Nef, and Tat were induced. Antibody responses were detected to each of the HIV antigens encoded by the DNA construct. Minimal doses of the GTU-MultiHIV DNA delivered by gene gun were potent in inducing significant HIV-specific CTL responses. The equivalent doses of the conventional plasmid expressing MultiHIV DNA delivered by gene gun failed to do so. An ideal DNA vaccine should yield high expression of the viral antigens for a prolonged period of time, and expression of the multiple viral antigens is probably required for the induction of a broad and protective immune response. The GTU-MultiHIV DNA vaccine described is a good vaccine candidate that meets the above criteria. PMID:16831091

  10. Experimental induction of type 2 diabetes in aging-accelerated mice triggered Alzheimer-like pathology and memory deficits.

    PubMed

    Mehla, Jogender; Chauhan, Balwantsinh C; Chauhan, Neelima B

    2014-01-01

    Alzheimer's disease (AD) is an age-dependent neurodegenerative disease constituting ~95% of late-onset non-familial/sporadic AD, and only ~5% accounting for early-onset familial AD. Availability of a pertinent model representing sporadic AD is essential for testing candidate therapies. Emerging evidence indicates a causal link between diabetes and AD. People with diabetes are >1.5-fold more likely to develop AD. Senescence-accelerated mouse model (SAMP8) of accelerated aging displays many features occurring early in AD. Given the role played by diabetes in the pre-disposition of AD, and the utility of SAMP8 non-transgenic mouse model of accelerated aging, we examined if high fat diet-induced experimental type 2 diabetes in SAMP8 mice will trigger pathological aging of the brain. Results showed that compared to non-diabetic SAMP8 mice, diabetic SAMP8 mice exhibited increased cerebral amyloid-β, dysregulated tau-phosphorylating glycogen synthase kinase 3β, reduced synaptophysin immunoreactivity, and displayed memory deficits, indicating Alzheimer-like changes. High fat diet-induced type 2 diabetic SAMP8 mice may represent the metabolic model of AD.

  11. Transcriptome Signatures Reveal Rapid Induction of Immune-Responsive Genes in Human Memory CD8+ T Cells

    PubMed Central

    Yang, Cheng; Khanniche, Asma; DiSpirito, Joanna R.; Ji, Ping; Wang, Shujun; Wang, Ying; Shen, Hao

    2016-01-01

    Memory T cells (TM) play a prominent role in protection and auto-immunity due to their ability to mount a more effective response than naïve T cells (TN). However, the molecular mechanisms underlying enhanced functionality of TM are not well defined, particularly in human TM. We examined the global gene expression profiles of human CD8+ TN and TM before and after stimulation. There were 1,284, 1,373 and 1,629 differentially expressed genes between TN and TM at 0 hr, 4 hr and 24 hr after stimulation, respectively, with more genes expressed to higher levels in TM. Genes rapidly up-regulated in TN cells were largely involved in nitrogen, nucleoside and amino acid metabolisms. In contrast, those in CD8+ TM were significantly enriched for immune-response-associated processes, including cytokine production, lymphocyte activation and chemotaxis. Multiple cytokines were rapidly up-regulated in TM cells, including effector cytokines known to be produced by CD8+ T cells and important for their functions, as well as regulatory cytokines, both pro- and anti-inflammatory, that are not typically produced by CD8+ T cells. These results provide new insights into molecular mechanisms that contribute to the enhanced functionality of human CD8+ TM and their prominent role in protection and auto-immunity. PMID:27243788

  12. Transcriptome Signatures Reveal Rapid Induction of Immune-Responsive Genes in Human Memory CD8(+) T Cells.

    PubMed

    Yang, Cheng; Khanniche, Asma; DiSpirito, Joanna R; Ji, Ping; Wang, Shujun; Wang, Ying; Shen, Hao

    2016-01-01

    Memory T cells (TM) play a prominent role in protection and auto-immunity due to their ability to mount a more effective response than naïve T cells (TN). However, the molecular mechanisms underlying enhanced functionality of TM are not well defined, particularly in human TM. We examined the global gene expression profiles of human CD8(+) TN and TM before and after stimulation. There were 1,284, 1,373 and 1,629 differentially expressed genes between TN and TM at 0 hr, 4 hr and 24 hr after stimulation, respectively, with more genes expressed to higher levels in TM. Genes rapidly up-regulated in TN cells were largely involved in nitrogen, nucleoside and amino acid metabolisms. In contrast, those in CD8(+) TM were significantly enriched for immune-response-associated processes, including cytokine production, lymphocyte activation and chemotaxis. Multiple cytokines were rapidly up-regulated in TM cells, including effector cytokines known to be produced by CD8(+) T cells and important for their functions, as well as regulatory cytokines, both pro- and anti-inflammatory, that are not typically produced by CD8(+) T cells. These results provide new insights into molecular mechanisms that contribute to the enhanced functionality of human CD8(+) TM and their prominent role in protection and auto-immunity. PMID:27243788

  13. Experimental Induction of Type 2 Diabetes in Aging-Accelerated Mice Triggered Alzheimer-Like Pathology and Memory Deficits

    PubMed Central

    Mehla, Jogender; Chauhan, Balwantsinh C.; Chauhan, Neelima B.

    2014-01-01

    Alzheimer’s disease (AD) is an age-dependent neurodegenerative disease constituting ~95% of late-onset non-familial/sporadic AD, and only ~5% accounting for early-onset familial AD. Availability of a pertinent model representing sporadic AD is essential for testing candidate therapies. Emerging evidence indicates a causal link between diabetes and AD. People with diabetes are >1.5-fold more likely to develop AD. Senescence-accelerated mouse model (SAMP8) of accelerated aging displays many features occurring early in AD. Given the role played by diabetes in the pre-disposition of AD, and the utility of SAMP8 non-transgenic mouse model of accelerated aging, we examined if high fat diet-induced experimental type 2 diabetes in SAMP8 mice will trigger pathological aging of the brain. Results showed that compared to non-diabetic SAMP8 mice, diabetic SAMP8 mice exhibited increased cerebral amyloid-β, dysregulated tau-phosphorylating glycogen synthase kinase 3β, reduced synaptophysin immunoreactivity, and displayed memory deficits, indicating Alzheimer-like changes. High fat diet-induced type 2 diabetic SAMP8 mice may represent the metabolic model of AD. PMID:24121970

  14. Induction of autoimmune diabetes by oral administration of autoantigen.

    PubMed

    Blanas, E; Carbone, F R; Allison, J; Miller, J F; Heath, W R

    1996-12-01

    An antigen administered orally can induce immunological tolerance to a subsequent challenge with the same antigen. Evidence has been provided for the efficacy of this approach in the treatment of human autoimmune diseases such as rheumatoid arthritis and multiple sclerosis. However, oral administration of autoantigen in mice was found to induce a cytotoxic T lymphocyte response that could lead to the onset of autoimmune diabetes. Thus, feeding autoantigen can cause autoimmunity, which suggests that caution should be used when applying this approach to the treatment of human autoimmune diseases. PMID:8939860

  15. Induction of anti-allo-class I H-2 tolerance by inactivation of CD8+ helper T cells, and reversal of tolerance through introduction of third- party helper T cells

    PubMed Central

    1990-01-01

    The intravenous sensitization of C57BL/6 (B6) mice with class I H-2- disparate B6-C-H-2bm1 (bm1) spleen cells resulted in the abrogation of CD8+ T cell-mediated anti-bm1 (proliferative and interleukin 2- producing) T helper (Th) cell activities. In vitro stimulation of lymphoid cells from these mice with bm1 cells, however, generated a reduced, but appreciable, anti-bm1 cytotoxic T lymphocyte (CTL) response. Moreover, the anti-bm1 CTL response, upon stimulation with [bm1 x B6-C-H-2bm12 (bm12)]F1 spleen cells, was enhanced when compared with the response induced upon stimulation with bm1 cells. These in vitro results were reflected on in vivo graft rejection responses; bm1 skin grafts engrafted in the bm1-presensitized B6 mice exhibited prolonged survival, whereas (bm1 x bm12)F1 grafts placed collateral to bm1 grafts (dual engrafted mice) inhibited the tolerance to bm1. In the B6 mice 1-2 d after rejecting the bm1 grafts, anti-bm1 Th activities remained marginal, whereas potent anti-bm1 CTL responses were found to be generated from their spleen cells. Administration in vivo of anti- CD4 antibody into bm1-presensitized, dual graft-engrafted mice prolonged bm1 graft survival and interfered with enhanced induction of anti-bm1 CTL activity. These results indicate that anti-class I alloantigen (bm1) tolerance as induced by intravenous presensitization with the relevant antigens is not ascribed to the elimination of CD8+ CTL precursors, but to the specific inactivation of CD8+ Th cells, whose function can be bypassed by activating third-party Th cells. PMID:2141624

  16. A tumor lysate is an effective vaccine antigen for the stimulation of CD4+ T-cell function and subsequent induction of antitumor immunity mediated by CD8+ T cells

    PubMed Central

    Kawahara, Mamoru; Takaku, Hiroshi

    2015-01-01

    To develop a potent cancer vaccine, it is important to study how to prepare highly immunogenic antigens and to identify the most appropriate adjuvants for the antigens. Here we show that a tumor lysate works as an effective antigen to prime CD4+ T-cell help when baculovirus is employed as an adjuvant. When immunized intradermally with the combination (BLP) of baculovirus, a CT26 tumor lysate, and a cytotoxic T-cell epitope peptide before a tumor challenge, 60% of mice rejected tumors. In contrast, all mice vaccinated with baculovirus plus a tumor lysate (BL) developed tumors. In addition, flow cytometry showed that tumor-specific, interferon γ-producing CD8+ cytotoxic T lymphocytes (CTLs) were robustly activated by intradermal immunization with BLP. When BLP was administered therapeutically to tumor-bearing mice, antitumor efficacy was better compared to BL. The established tumor was completely eradicated in 50–60% of BLP-treated mice, and induction of tumor-specific CTLs was observed, suggesting that the antitumor efficacy of BLP is mediated by CD8+ T cells. Numerous CD4+ T cells infiltrated the tumors of BLP-treated mice, whereas the antitumor effect of BLP almost disappeared after removal of the tumor lysate from BLP or after depletion of BLP-immunized mice of CD4+ T cells. Thus, the combination of a peptide, lysate, and baculovirus provides stronger antitumor immunity than does a peptide plus baculovirus or a lysate plus baculovirus; effectiveness of BLP is determined by functioning of CD4+ T cells stimulated with a tumor lysate. PMID:26391871

  17. Induction of methotrexate resistance by retroviral-mediated transfer of a mutant dihydrofolate reductase gene

    SciTech Connect

    Ricciardone, M.D.

    1986-01-01

    Methotrexate (MTX), a folate analog which inhibits the enzyme dihydrofolate reductase (DHFR), is an effective antineoplastic drug. However, MTX-induced myelosuppression limits the effectiveness of this agent. Selective induction of MTX resistance in bone marrow stem cells, prior to treatment with MTX, might prevent this toxicity and improve the therapeutic index of the drug. In these studies drug resistance was transferred to mouse and human bone marrow stem cells by retroviral expression vectors containing coding sequences of a mutant DHFR with a decreased affinity for MTX. Three retroviral expression vectors were analyzed. The CIS DR vector contained the mutant DHFR gene inserted into the replication-defective amphotropic 4070 virus, Cistor. The other vectors contained the mutant DHFR inserted into either the env region (SDHT1) or gag-pol region (SDHT2) of a replication-defective spleen focus-forming virus. All three constructs induced approximately a 200-fold resistance to MTX when transfected into NIH3T3 cells. Amphotropic infectious retroviruses were obtained by transfecting the mutant DHFR vectors into a packaging cell line, which supplied the gag, pol, and env proteins for virus production. Virus titers of 4.5 x 10/sup 3/ colony-forming units (CFU)/ml (CIS DR), 1.5 x 10/sup 4/ CFU/ml (SDHT2), and 5 x 10/sup 5/ CFU/ml (SDHT1) were measured by the transfer of MTX resistance to NIH3T3 cells. The amphotropic SDHT1 virus efficiently induced MTX resistance in cells of several species, including mouse NIH3T3 cells (5 x 10/sup 5/ CFU/ml), monkey CV1 cells (4 x 10/sup 3/ CFU/ml), and human MCF-7 cells (6 x 10/sup 4/ CFU/ml). When cocultured with SDHT1 virus-producing cells, both mouse and human bone marrow cells could be infected and rendered resistant to MTX. Mouse cytotoxic T lymphocytes and mouse helper T lymphocytes can also be made resistant to MTX.

  18. [Changes of T-cell clonality after induction-cultivation of peripheral T lymphocytes in adoptive immunotherapy for leukemias].

    PubMed

    Liu, Yan; Gu, Jiang-Ying; Ou, Yuan; Li, Mian-Yang; Wang, He; Jin, Xian; Tao, Xiu-Yan; Liu, Zhao-Li; Ma, Xing-Fan; Wang, Xiu-Li; Ma, Si-Kun; Kang, Rui; Cai, Peng; Tong, Chun-Rong; Zhu, Ping

    2009-06-01

    This study was purposed to analyze the changes of T-cell clonality after induction of peripheral T lymphocytes by autogenous DC and cytokines in the preparation of adoptive immunotherapy for leukemias. The bone marrow and peripheral blood from 21 leukemia patients at remission stage after treatment and subjected to adoptive immunotherapy were collected. Their DCs and T-cells were stimulated with cytokines and then were mixed to activate T-cells. T-cell receptor beta variable region (TCRBV) families were amplified by RT-PCR, and genescan method and sequencing of the PCR products were used to observe the clonality changes of T-cells before and after the induction and cultivation of T-cells. The flow cytometry was used to identify CD3(+), CD4(+), CD8(+), CD3(+)CD56(+) and CD4(+)CD25str(+)FOXP3(+) cells to disclose the ratio change of cytotoxic T lymphocytes (CTL), helper T-cells, regulatory T-cells and NK T-cells before and after induction and cultivation of T-cells. The results showed that in the 21 patients, most of the 24 TCRBV families presented as oligoclonal distribution on genescan, several families were not expressed, and only a few families remained polyclonal. TCRBV24 was found to be oligoclonal in all of the 21 patients. DNA sequence analysis of TCRBV24 revealed a common motif of VAG in CDR3 in 3 cases and a common motif of GGG in CDR3 in 2 cases. In patient 5, both TCRBV 24 and TCRBV8 contained the same motif of GGG in CDR3. The identical motif in these patients may suggest that these T-cells recognize the same antigen. The peripheral lymphocytes demonstrated recovery of clonal profile on genescan from oligoclonal profile and absence of several families before the induction and cultivation to typical polyclonal profile in all TCRBV families after the induction by DC and cytokines for 13 days. After the induction and cultivation, the number of lymphocytes increased to 3.38 +/- 1.20 times. CD3(+), CD4(+), CD8(+), CD3(+)CD56(+) and CD4(+)CD25str(+)FOX P3

  19. Predicting Reasoning from Memory

    ERIC Educational Resources Information Center

    Heit, Evan; Hayes, Brett K.

    2011-01-01

    In an effort to assess the relations between reasoning and memory, in 8 experiments, the authors examined how well responses on an inductive reasoning task are predicted from responses on a recognition memory task for the same picture stimuli. Across several experimental manipulations, such as varying study time, presentation frequency, and the…

  20. Antigen-dependent proliferation and cytokine induction in respiratory syncytial virus-infected cotton rats reflect the presence of effector-memory T cells

    SciTech Connect

    Richter, Bettina W.M.; Onuska, Jaya M.; Niewiesk, Stefan; Prince, Gregory A.; Eichelberger, Maryna C. . E-mail: MarynaE@virionsystems.com

    2005-06-20

    Respiratory syncytial virus (RSV) is a major cause of lower airway disease in infants and children. Immunity to RSV is not long lasting, resulting in re-occurring infections throughout life. Effective long-lived immunity results when central-memory T cells that proliferate vigorously and secrete IL-2 are present. In contrast, effector-memory T cells that mainly produce IFN-{gamma}, facilitate virus clearance but are not long lived. To identify the type of memory response induced after RSV-A (Long) infection, we characterized the kinetics of the antigen-specific immune response and identified the types of cytokines induced. RSV-specific lymphocytic proliferation following primary and secondary infection was similar, and in both cases responses waned within a short period of time. In addition, mRNA for IFN-{gamma} but not IL-2 was induced in RSV-specific CD4{sup +} T cells. This supports the idea that the presence of effector-memory rather than central-memory T cells contributes to the ineffectiveness of the immune response to RSV.

  1. The Contribution of Spatial and Temporal Molecular Networks in the Induction of Long-term Memory and Its Underlying Synaptic Plasticity

    PubMed Central

    Mirisis, Anastasios A.; Alexandrescu, Anamaria; Carew, Thomas J.; Kopec, Ashley M.

    2016-01-01

    The ability to form long-lasting memories is critical to survival and thus is highly conserved across the animal kingdom. By virtue of its complexity, this same ability is vulnerable to disruption by a wide variety of neuronal traumas and pathologies. To identify effective therapies with which to treat memory disorders, it is critical to have a clear understanding of the cellular and molecular mechanisms which subserve normal learning and memory. A significant challenge to achieving this level of understanding is posed by the wide range of distinct temporal and spatial profiles of molecular signaling induced by learning-related stimuli. In this review we propose that a useful framework within which to address this challenge is to view the molecular foundation of long-lasting plasticity as composed of unique spatial and temporal molecular networks that mediate signaling both within neurons (such as via kinase signaling) as well as between neurons (such as via growth factor signaling). We propose that evaluating how cells integrate and interpret these concurrent and interacting molecular networks has the potential to significantly advance our understanding of the mechanisms underlying learning and memory formation.

  2. Prostaglandin E2 EP2 activation reduces memory decline in R6/1 mouse model of Huntington's disease by the induction of BDNF-dependent synaptic plasticity.

    PubMed

    Anglada-Huguet, Marta; Vidal-Sancho, Laura; Giralt, Albert; García-Díaz Barriga, Gerardo; Xifró, Xavier; Alberch, Jordi

    2016-11-01

    Huntington's disease (HD) patients and mouse models show learning and memory impairment even before the onset of motor symptoms. Deficits in hippocampal synaptic plasticity have been involved in the HD memory impairment. Several studies show that prostaglandin E2 (PGE2) EP2 receptor stimulates synaptic plasticity and memory formation. However, this role was not explored in neurodegenerative diseases. Here, we investigated the capacity of PGE2 EP2 receptor to promote synaptic plasticity and memory improvements in a model of HD, the R6/1 mice, by administration of the agonist misoprostol. We found that misoprostol increases dendritic branching in cultured hippocampal neurons in a brain-derived neurotrophic factor (BDNF)-dependent manner. Then, we implanted an osmotic mini-pump system to chronically administrate misoprostol to R6/1 mice from 14 to 18weeks of age. We observed that misoprostol treatment ameliorates the R6/1 long-term memory deficits as analyzed by the T-maze spontaneous alternation task and the novel object recognition test. Importantly, administration of misoprostol promoted the expression of hippocampal BDNF. Moreover, the treatment with misoprostol in R6/1 mice blocked the reduction in the number of PSD-95 and VGluT-1 positive particles observed in hippocampus of vehicle-R6/1 mice. In addition, we observed an increase of cAMP levels in the dentate ` of WT and R6/1 mice treated with misoprostol. Accordingly, we showed a reduction in the number of mutant huntingtin nuclear inclusions in the dentate gyrus of R6/1 mice. Altogether, these results suggest a putative therapeutic effect of PGE2 EP2 receptor in reducing cognitive deficits in HD.

  3. Expression of chicken interleukin-2 by a highly virulent strain of Newcastle disease virus leads to decreased systemic viral load but does not significantly affect mortality in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In mammals, interleukin 2 (IL-2) has been shown to decrease replication or attenuate pathogenicity of numerous viral pathogens by activating natural killer cells (NK), cytotoxic T lymphocytes, and expanding subsets of memory cells. In chickens, IL-2 has been shown to activate T cells, and as such i...

  4. Induction linacs

    SciTech Connect

    Keefe, D.

    1986-07-01

    The principle of linear induction acceleration is described, and examples are given of practical configurations for induction linacs. These examples include the Advanced Technology Accelerator, Long Pulse Induction Linac, Radial Line Accelerator (RADLAC), and Magnetically-Insulated Electron-Focussed Ion Linac. A related concept, the auto accelerator, is described in which the high-current electron-beam technology in the sub-10 MeV region is exploited to produce electron beams at energies perhaps as high as the 100 to 1000 MeV range. Induction linacs for ions are also discussed. The efficiency of induction linear acceleration is analyzed. (LEW)

  5. The olfactory memory of the honeybee Apis mellifera. III. Bilateral sensory input is necessary for induction and expression of olfactory blocking.

    PubMed

    Thorn, R S; Smith, B H

    1997-07-01

    The associative learning phenomenon termed 'blocking' demonstrates that animals do not necessarily associate a conditioned stimulus (e.g. X) with reinforcement if X is coincident with a second conditioned stimulus (e.g. A) that had already been associated with the same reinforcement. Blocking therefore represents a tactic that animals can use to modulate associative learning in order to focus on the most predictive stimuli at the expense of novel ones. Using an olfactory blocking paradigm in the honeybee, we investigated the mechanistic basis for olfactory blocking. We show that removing input from one antenna eliminates the blocking of one odor by another. Since antennal sensory neurons only project to the ipsilateral antennal lobe in the honeybee, more central processing regions of the brain than the antennae must be crucial for establishing blocking. Further experiments show that this bilateral interaction between brain hemispheres is crucial during both the induction and the expression of blocking. This result implies that blocking involves an active inhibition of odor association and recall, and that this inhibition is mediated by a structure that spans both brain hemispheres. This interpretation is consistent with a role for identified bilateral modulatory neurons in the production of blocking.

  6. Focal Radiation Therapy Combined with 4-1BB Activation and CTLA-4 Blockade Yields Long-Term Survival and a Protective Antigen-Specific Memory Response in a Murine Glioma Model

    PubMed Central

    Belcaid, Zineb; Phallen, Jillian A.; Zeng, Jing; See, Alfred P.; Mathios, Dimitrios; Gottschalk, Chelsea; Nicholas, Sarah; Kellett, Meghan; Ruzevick, Jacob; Jackson, Christopher; Albesiano, Emilia; Durham, Nicholas M.; Ye, Xiaobu; Tran, Phuoc T.; Tyler, Betty; Wong, John W.; Brem, Henry; Pardoll, Drew M.; Drake, Charles G.; Lim, Michael

    2014-01-01

    Background Glioblastoma (GBM) is the most common malignant brain tumor in adults and is associated with a poor prognosis. Cytotoxic T lymphocyte antigen -4 (CTLA-4) blocking antibodies have demonstrated an ability to generate robust antitumor immune responses against a variety of solid tumors. 4-1BB (CD137) is expressed by activated T lymphocytes and served as a co-stimulatory signal, which promotes cytotoxic function. Here, we evaluate a combination immunotherapy regimen involving 4-1BB activation, CTLA-4 blockade, and focal radiation therapy in an immune-competent intracranial GBM model. Methods GL261-luciferace cells were stereotactically implanted in the striatum of C57BL/6 mice. Mice were treated with a triple therapy regimen consisted of 4-1BB agonist antibodies, CTLA-4 blocking antibodies, and focal radiation therapy using a small animal radiation research platform and mice were followed for survival. Numbers of brain-infiltrating lymphocytes were analyzed by FACS analysis. CD4 or CD8 depleting antibodies were administered to determine the relative contribution of T helper and cytotoxic T cells in this regimen. To evaluate the ability of this immunotherapy to generate an antigen-specific memory response, long-term survivors were re-challenged with GL261 glioma en B16 melanoma flank tumors. Results Mice treated with triple therapy had increased survival compared to mice treated with focal radiation therapy and immunotherapy with 4-1BB activation and CTLA-4 blockade. Animals treated with triple therapy exhibited at least 50% long-term tumor free survival. Treatment with triple therapy resulted in a higher density of CD4+ and CD8+ tumor infiltrating lymphocytes. Mechanistically, depletion of CD4+ T cells abrogated the antitumor efficacy of triple therapy, while depletion of CD8+ T cells had no effect on the treatment response. Conclusion Combination therapy with 4-1BB activation and CTLA-4 blockade in the setting of focal radiation therapy improves survival in

  7. Applying a dual process model of self-regulation: The association between executive working memory capacity, negative urgency, and negative mood induction on pre-potent response inhibition

    PubMed Central

    Gunn, Rachel L.; Finn, Peter R.

    2014-01-01

    This study tested a dual-process model of self-control where the combination of high impulsivity (negative urgency – NU), weak reflective / control processes (low executive working memory capacity - E-WMC), and a cognitive load is associated with increased failures to inhibit pre-potent responses on a cued go/no-go task. Using a within-subjects design, a cognitive load with and without negative emotional load was implemented to consider situational factors. Results suggested that: (1) high NU was associated with low E-WMC; (2) low E-WMC significantly predicted more inhibitory control failures across tasks; and (3) there was a significant interaction of E-WMC and NU, revealing those with low E-WMC and high NU had the highest rates of inhibitory control failures on all conditions of the task. In conclusion, results suggest that while E-WMC is a strong independent predictor of inhibitory control, NU provides additional information for vulnerability to problems associated with self-regulation. PMID:25530648

  8. Inducting Principals.

    ERIC Educational Resources Information Center

    Andrews, Carl

    1989-01-01

    Principal induction is the process by which new school principals make the transition from theoretical to operational leadership. Many approaches to induction have been tried, ranging from simply handing over the building keys to comprehensive career development programs. To exemplify ongoing research and development in educational administration…

  9. Identification of the murine H-2D(b) and human HLA-A*0201 MHC class I-restricted HPV6 E7-specific cytotoxic T lymphocyte epitopes.

    PubMed

    Peng, Shiwen; Mattox, Austin; Best, Simon R; Barbu, Anca M; Burns, James A; Akpeng, Belinda; Jeang, Jessica; Yang, Benjamin; Ishida, Eiichi; Hung, Chien-Fu; Wu, Tzyy-Choou; Pai, Sara I

    2016-03-01

    Recurrent respiratory papillomatosis is caused by human papillomavirus (HPV) infection, most commonly types 6 (HPV-6) and 11 (HPV-11). Due to failed host immune responses, HPV is unable to be cleared from the host, resulting in recurrent growth of HPV-related lesions that can obstruct the lumen of the airway within the upper aerodigestive tract. In our murine model, the HPV-6b and HPV-11 E7 antigens are not innately immunogenic. In order to enhance the host immune responses against the HPV E7 antigen, we linked calreticulin (CRT) to HPV-6b E7 and found that vaccinating C57BL/6 mice with the HPV-6b CRT/E7 DNA vaccine is able to induce a CD8+ T cell response that recognizes an H-2D(b)-restricted E7aa21-29 epitope. Additionally, vaccination of HLA-A*0201 transgenic mice with HPV-6b CRT/E7 DNA generated a CD8+ T cell response against the E7aa82-90 epitope that was not observed in the wild-type C57BL/6 mice, indicating this T cell response is restricted to HLA-A*0201. In vivo cytotoxic T cell killing assays demonstrated that the vaccine-induced CD8+ T cells are able to efficiently kill target cells. Interestingly, the H-2D(b)-restricted E7aa21-29 sequence and the HLA-A*0201-restricted E7aa82-90 sequence are conserved between HPV-6b and HPV-11 and may represent shared immunogenic epitopes. The identification of the HPV-6b/HPV-11 CD8+ T cell epitopes facilitates the evaluation of various immunomodulatory strategies in preclinical models. More importantly, the identified HLA-A*0201-restricted T cell epitope may serve as a peptide vaccination strategy, as well as facilitate the monitoring of vaccine-induced HPV-specific immunologic responses in future human clinical trials.

  10. Identification of the murine H-2D(b) and human HLA-A*0201 MHC class I-restricted HPV6 E7-specific cytotoxic T lymphocyte epitopes.

    PubMed

    Peng, Shiwen; Mattox, Austin; Best, Simon R; Barbu, Anca M; Burns, James A; Akpeng, Belinda; Jeang, Jessica; Yang, Benjamin; Ishida, Eiichi; Hung, Chien-Fu; Wu, Tzyy-Choou; Pai, Sara I

    2016-03-01

    Recurrent respiratory papillomatosis is caused by human papillomavirus (HPV) infection, most commonly types 6 (HPV-6) and 11 (HPV-11). Due to failed host immune responses, HPV is unable to be cleared from the host, resulting in recurrent growth of HPV-related lesions that can obstruct the lumen of the airway within the upper aerodigestive tract. In our murine model, the HPV-6b and HPV-11 E7 antigens are not innately immunogenic. In order to enhance the host immune responses against the HPV E7 antigen, we linked calreticulin (CRT) to HPV-6b E7 and found that vaccinating C57BL/6 mice with the HPV-6b CRT/E7 DNA vaccine is able to induce a CD8+ T cell response that recognizes an H-2D(b)-restricted E7aa21-29 epitope. Additionally, vaccination of HLA-A*0201 transgenic mice with HPV-6b CRT/E7 DNA generated a CD8+ T cell response against the E7aa82-90 epitope that was not observed in the wild-type C57BL/6 mice, indicating this T cell response is restricted to HLA-A*0201. In vivo cytotoxic T cell killing assays demonstrated that the vaccine-induced CD8+ T cells are able to efficiently kill target cells. Interestingly, the H-2D(b)-restricted E7aa21-29 sequence and the HLA-A*0201-restricted E7aa82-90 sequence are conserved between HPV-6b and HPV-11 and may represent shared immunogenic epitopes. The identification of the HPV-6b/HPV-11 CD8+ T cell epitopes facilitates the evaluation of various immunomodulatory strategies in preclinical models. More importantly, the identified HLA-A*0201-restricted T cell epitope may serve as a peptide vaccination strategy, as well as facilitate the monitoring of vaccine-induced HPV-specific immunologic responses in future human clinical trials. PMID:26759151

  11. Abatacept (cytotoxic T lymphocyte antigen 4-immunoglobulin) improves B cell function and regulatory T cell inhibitory capacity in rheumatoid arthritis patients non-responding to anti-tumour necrosis factor-α agents

    PubMed Central

    Picchianti Diamanti, A; Rosado, M M; Scarsella, M; Germano, V; Giorda, E; Cascioli, S; Laganà, B; D'Amelio, R; Carsetti, R

    2014-01-01

    The use of biological agents combined with methotrexate (MTX) in rheumatoid arthritis (RA) patients has strongly improved disease outcome. In this study, the effects of abatacept on the size and function of circulating B and T cells in RA patients not responding to anti-tumour necrosis factor (TNF)-α have been analysed, with the aim of identifying immunological parameters helpful to choosing suitable tailored therapies. We analysed the frequency of peripheral B and T cell subsets, B cell function and T regulatory cell (Treg) inhibitory function in 20 moderate/severe RA patients, according to the European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) criteria, primary non-responders to one TNF-α blocking agent, who received abatacept + MTX. Patients were studied before and 6 months after therapy. We found that abatacept therapy significantly reduced disease activity score on 44 joints (DAS)/erythrocyte sedimentation rate (ESR) values without causing severe side effects. The size of the circulating B and T cell compartments in RA patients was not significantly different from healthy donors, but B cell proliferation and plasma cell differentiation was impaired before therapy and restored by abatacept. While Treg cell frequency was normal, its inhibitory function was absent before therapy and was partially recovered 6 months after abatacept. B and Treg cell function is impaired in RA patients not responding to the first anti-TNF-α agent. Abatacept therapy was able to rescue immune function and led to an effective and safe clinical outcome, suggesting that RA patients, in whom anti-TNF-α failed, are immunologically prone to benefit from an agent targeting a different pathway. PMID:24773026

  12. Amino acid substitutions at position 97 in HLA-A2 segregate cytolysis from cytokine release in MART-1/Melan-A peptide AAGIGILTV-specific cytotoxic T lymphocytes.

    PubMed

    Maeurer, M J; Chan, H W; Karbach, J; Salter, R D; Knuth, A; Lotze, M T; Storkus, W J

    1996-11-01

    CD8+ T lymphocytes recognize antigenic peptides presented by major histocompatibility complex (MHC) class I molecules. Individual peptide termini appear to be fixed at the C- and N-terminal ends. In contrast, central peptide side chains residues may point in different directions and exhibit limited flexibility, dependent on the MHC class I structural variation. For instance, position 97 in HLA-A201 has been shown to shift individual peptide species into different coordinations, one oriented towards the peptide N terminus, or more towards the C-terminal end. The conformational shape of such non-anchor peptide residues may affect the affinity of MHC/peptide/TCR interaction, resulting in quantitative, or qualitative different T cell effector functions. To characterize the impact of different amino acid residues occupying position 97 in HLA-A2 on peptide binding and presentation to CTL, we generated a panel of mutated HLA-A2 molecules containing either M, K, T, V, G, Q, W, P or H at position 97. The HLA-A0201 presented melanoma-associated MART-1/Melan-A derived peptide AAGIGILTV was employed to assess the impact of such position-97 mutations on HLA-A2 in peptide binding measured in an HLA-A2 reconstitution assay and presentation to AAGIGILTV-specific polyclonal or clonal T lymphocytes as measured by cytotoxicity, or interferon (IFN)-gamma and granulocyte/ macrophage colony-stimulating factor (GM-CSF) secretion. The high-affinity AAGIGILTV peptide bound to all position-97 mutants, albeit with differential efficiencies, and elicited specific release of IFN-gamma and GM-CSF by CTL. CTL responses were triggered only by the HLA-A2 wild type, by HLA-A2-H97 (histidine position 97 mutant), and HLA-A2-W97. The HLA-A2-M97 presenting molecule elicited enhanced cytokine release and CTL effector functions by polyclonal and by clonal effector T cells. These results indicate that MHC class I-bound peptides can trigger specific cytokine release by effector T cells independently of their ability to induce cytolysis. We conclude that relatively minor changes in the MHC class I peptide binding groove, including substitutions at position 97, can affect recognition by antigen-specific T cells. Mutant MHC class I molecules, such as those described here, may act as partial peptide antagonists and could be useful for inducing T lymphocytes with qualitatively different effector functions. PMID:8921947

  13. The CD8 coreceptor interaction with the alpha 3 domain of HLA class I is critical to the differentiation of human cytotoxic T-lymphocytes specific for HLA-A2 and HLA-Cw4.

    PubMed

    Wesley, P K; Clayberger, C; Lyu, S C; Krensky, A M

    1993-03-01

    The CD8 coreceptor interacts with MHC class I molecules through an acidic loop in the MHC alpha 3 domain. Mutations in this region reduced binding between cells expressing mutant HLA molecules and CHO cells transfected with CD8 alpha chain, with mutations at residue 227 having the greatest effects. This study was undertaken to examine the role of the CD8-HLA interaction in the generation of primary and long-term CTLs. HLA-A*0201 genes (wild type or mutated at residue 227) were transfected into a cell line that lacked expression of HLA-A or B molecules but expressed HLA-Cw4. These cells were used as stimulators for PBLs from a normal donor. Cultures were tested for cytotoxicity at various times thereafter. Transfectants expressing the HLA-A*0201 mutant gene were poor stimulators of primary HLA-A2-specific CTLs. In long-term culture, HLA-Cw4-specific CTLs predominated, indicating that continuous expansion of allogeneic CTLs depends upon an efficient CD8-MHC class I interaction. PMID:8320133

  14. Synthetic peptides derived from the melanocyte-stimulating hormone receptor MC1R can stimulate HLA-A2-restricted cytotoxic T lymphocytes that recognize naturally processed peptides on human melanoma cells.

    PubMed

    Salazar-Onfray, F; Nakazawa, T; Chhajlani, V; Petersson, M; Kärre, K; Masucci, G; Celis, E; Sette, A; Southwood, S; Appella, E; Kiessling, R

    1997-10-01

    Human melanoma-specific HLA-A2 restricted CTLs have recently been shown to recognize antigens expressed by melanoma lines and normal melanocytes, including Melan-A/Mart-1, gp100, gp75, and tyrosinase. Herein, we define HLA-A2-restricted CTL epitopes from a recently cloned melanocortin 1 receptor (MC1R), which belongs to a new subfamily of the G-protein-coupled receptors expressed on melanomas and melanocytes. Thirty-one MC1R-derived peptides were selected on the basis of HLA-A2-specific motifs and tested for their HLA-A2 binding capacity. Of a group of 12 high or intermediate HLA-A2 binding peptides, three nonamers, MC1R244 (TILLGIFFL), MC1R283 (FLALIICNA), and MC1R291 (AIIDPLIYA), were found to induce peptide-specific CTLs from peripheral blood mononuclear cells of healthy HLA-A2+ donors after repeated in vitro stimulation with peptide-pulsed antigen-presenting cells. The CTLs raised against these three HLA-A2+-restricted peptides could recognize naturally processed peptides from HLA-A2+ melanomas and from Cos7 cells cotransfected with MC1R and HLA-A2. CTLs induced by the MC1R291 peptide (but not induced or induced only to a very low extent by the other two MCR1 peptide epitopes) showed cross-reactions with two other members of the melanocortin receptor family, which are more broadly expressed on other tissues. Taken together, our findings have implications in relation both to autoimmunity and immunotherapy of malignant melanomas. PMID:9331097

  15. Epstein-Barr virus-specific cytotoxic T lymphocytes as probes of HLA polymorphism. Heterogeneity of T cell-restricting determinants associated with the serologically defined HLA-A2 antigen.

    PubMed

    Gaston, J S; Rickinson, A B; Epstein, M A

    1983-08-01

    Epstein-Barr (EB) virus-specific effector T cell lines were established from nine virus-immune donors positive for the serologically defined HLA-A2 antigen; of these, four lines contained a demonstrable A2-restricted cytotoxic component. When these four effector populations were each tested on the same panel of EB virus-transformed lines from 20 HLA-A2-positive individuals, 16 of the target cell lines were consistently killed at levels above 25% of the relevant autologous cell lysis. Cytotoxicity appeared to be mediated through a restricting determinant associated with the 'common A2' antigen that these lines shared; indeed the lysis could be specifically blocked by high concentrations of an HLA-A2-specific monoclonal antibody. In contrast, 4 out of 20 target cell lines were not killed by HLA-A2-restricted effector cells, even though they did express the serologically defined A2 antigen and were found in other tests to be susceptible to EB virus-specific cytolysis restricted through other HLA-A or -B antigens on their surface. These results suggest that EB virus-specific cytotoxic T cells can distinguish between serologically identical HLA-A2 molecules via the heterogeneity of their T cell-restricting determinants. Data from one of the effector cell populations further suggested that a serologically defined cross-reaction between the otherwise distinct HLA-A2 and -Bw57 antigens might also be reflected in a cross-reactivity of T cell-restricting determinants. PMID:6193217

  16. Use of the V delta 1 variable region in the functional T-cell receptor alpha chain of a WT31+ cytotoxic T lymphocyte clone which specifically recognizes HLA-A2 molecule.

    PubMed

    Castelli, C; Mazzocchi, A; Salvi, S; Anichini, A; Sensi, M

    1992-04-01

    We report here the molecular characterization of the T-cell receptor (TCR) expressed by a human HLA-A2 specific cytotoxic T-cell clone named CTL 49. Flow cytometry analysis with a panel of anti-TCR antibodies revealed an OKT3+, WT31+, A13+, BB3-, TCR delta-, delta TCS1-, TCR gamma/delta 1-, OKT4-, and OKT8+ phenotype, suggesting that, in CTL 49, the V delta 1-encoded A13 epitope could be included in its alpha beta TCR. Northern blot analysis confirmed the presence of C alpha, C beta and V delta 1 specific transcripts while no hybridization signal was detected by a C delta specific probe. Polymerase chain reaction (PCR) amplification of the first strand cDNA from CTL 49 with TCR-specific primers and sequence analysis revealed that V delta 1 region is productively rearranged to J alpha and to C alpha regions. This alpha chain pairs with a beta chain composed of V beta 13.2/D beta/J beta 2.3/C beta 2 leading to the expression of a functional TCR complex. These results, in addition to providing further evidence for the sharing of V delta 1 by alpha/beta and gamma/delta TCR, indicate that an alpha/beta T-cell receptor which includes the V delta 1 variable region can be involved in alloreactive recognition. PMID:1313600

  17. Production of good manufacturing practice-grade cytotoxic T lymphocytes specific for Epstein-Barr virus, cytomegalovirus and adenovirus to prevent or treat viral infections post-allogeneic hematopoietic stem cell transplant.

    PubMed

    Sili, Uluhan; Leen, Ann M; Vera, Juan F; Gee, Adrian P; Huls, Helen; Heslop, Helen E; Bollard, Catherine M; Rooney, Cliona M

    2012-01-01

    Infections with a range of common community viruses remain a major cause of mortality and morbidity after allogeneic hematopoietic stem cell transplantation. T cells specific for cytomegalovirus (CMV), Epstein-Barr virus (EBV) and adenoviruses can safely prevent and infections with these three most common culprits, but the manufacture of individual T cell lines for each virus would be prohibitive in terms of time and cost. We have demonstrated that T cells specific for all three viruses can be manufactured in a single culture using monocytes and EBV-transformed B lymphoblastoid cell lines (LCLs), both transduced with an adenovirus vector expressing pp65 of CMV, as antigen-presenting cells. Trivirus-specific T cell lines produced from healthy stem cell donors could prevent and treat infections with all three viruses, not only in the designated recipient, but in unrelated, partially-HLA-matched third party recipients. We now provide the details and logistics of T cell manufacture.

  18. Association between Cytotoxic T-lymphocyte antigen 4 (CTLA-4) +49 G>A (rs231775) polymorphism and esophageal cancer: from a case-control study to a meta-analysis

    PubMed Central

    Liu, Chao; Wang, Yafeng; Jiang, Heping; Tang, Weifeng; Chen, Shuchen; Kang, Mingqiang; Dong, Changqing; Gu, Haiyong

    2015-01-01

    The aim of this study was to evaluate the association between CTLA-4 +49 G>A polymorphism and esophageal cancer (EC) susceptibility in a hospital based case-control study and a subsequent meta-analysis. We implemented genotyping analyses for CTLA-4 +49 G>A polymorphism with 629 esophageal squamous cell carcinoma cases and 686 controls in a Chinese Han population. Polymerase chain reaction ligase detection reaction (PCR-LDR) method was used to identify genotypes of CTLA-4 +49 G>A polymorphism. We first assessed the association between CTLA-4 +49 G>A polymorphism and EC risk in a hospital based case-control study, and then performed a comprehensive meta-analysis to derive a more precise estimation. Our results demonstrated that CTLA-4 +49 G>A polymorphism was not associated with EC risk. This case-control study and further meta-analysis, failed to identify the association between CTLA-4 +49 G>A polymorphism and EC risk. And additional, further well designed studies with large sample sizes and detailed gene-environment data are required. PMID:26770356

  19. Intradermal vaccination of adults with three low doses (2 micrograms) of recombinant hepatitis B vaccine. II. Persistence of immunity and induction of immunologic memory.

    PubMed

    Elisbão, Maria do Carmo M; Baldy, José Luís da S; Bonametti, Ana Maria; Reiche, Edna Maria V; Morimoto, Helena K; Pontello, Rubens; Matsuo, Tiemi; Ferelle, Antônio; Neves, Jayme

    2003-12-01

    Of the 110 dentists who had presented seroconversion 50 days after the intradermal application of three 2 micrograms doses of the Belgian recombinant vaccine against hepatitis B (HB), administered eight years before at an interval of one month between the 1st and 2nd doses and of five months between the 2nd and 3rd doses, 51 were included for the assessment of the persistence of immunity. None of the dentists had hepatitis or had received HB vaccine during this period. All subjects were submitted to serological tests for the detection of the following markers of hepatitis B virus (HBV) infection: HBsAg, anti-HBc, HBeAg, anti-HBe, and anti-HBs, with no HBsAg, anti-HBc, HBeAg or anti-HBe being detected. A microparticle enzyme immunoassay (MEIA) revealed the presence of anti-HBs at protective titers (> or = 10 mIU/ml) in 42 dentists (82.4%), with the anti-HBs titer being higher than 100 mIU/ml in 36 of them (70.6%) (good responders), between 10 and 100 mIU/ml in 6 (11.8%) (poor responders), and lower than 10 mIU/ml in 9 (17.6%) (non-responders). According to clinical data and serological tests, none of the dentists had presented disease or latent HBV infection during the eight years following the first vaccination. A 2 micrograms booster dose was administered intradermally to eight dentists with anti-HBs titers lower than 10 mIU/ml (non-responders) and to six dentists with titers ranging from 10 to 100 mIU/ml (poor responders); the determination of anti-HBs one month later demonstrated the occurrence of seroconversion in the eight non-responders and an increase in anti-HBs titer in the six poor responders. In summary, the present results demonstrated the prolonged persistence of protection against HBV infection and the development of immunologic memory provided by vaccination against HB--with intradermal application of three 2 micrograms doses of the Belgian recombinant vaccine at 0, 1, and 6 months--carried out eight years before in 51 dentists.

  20. Induction voidmeter

    DOEpatents

    Anderson, Thomas T.; Roop, Conard J.; Schmidt, Kenneth J.; Brewer, John

    1986-01-01

    An induction voidmeter for detecting voids in a conductive fluid may comprise: a four arm bridge circuit having two adjustable circuit elements connected as opposite arms of said bridge circuit, an input branch, and an output branch; two induction coils, bifilarly wound together, connected as the remaining two opposing arms of said bridge circuit and positioned such that the conductive fluid passes through said coils; applying an AC excitation signal to said input branch; and detecting the output signal generated in response to said excitation signal across said output branch. The induction coils may be located outside or inside a non-magnetic pipe containing the conductive fluid.

  1. Induction voidmeter

    DOEpatents

    Anderson, T.T.; Roop, C.J.; Schmidt, K.J.; Brewer, J.

    1983-12-21

    An induction voidmeter for detecting voids in a conductive fluid may comprise: a four arm bridge circuit having two adjustable circuit elements connected as opposite arms of said bridge, an input branch, and an output branch; two induction coils, bifilarly wound together, connected as the remaining two opposing arms of said bridge circuit and positioned such that the conductive fluid passes through said coils; means for applying an AC excitation signal to said input branch; and means for detecting the output signal generated in response to said excitation signal across said output branch. The induction coils may be located outside or inside a non-magnetic pipe containing the conductive fluid.

  2. Mechanical memory

    DOEpatents

    Gilkey, Jeffrey C.; Duesterhaus, Michelle A.; Peter, Frank J.; Renn, Rosemarie A.; Baker, Michael S.

    2006-08-15

    A first-in-first-out (FIFO) microelectromechanical memory apparatus (also termed a mechanical memory) is disclosed. The mechanical memory utilizes a plurality of memory cells, with each memory cell having a beam which can be bowed in either of two directions of curvature to indicate two different logic states for that memory cell. The memory cells can be arranged around a wheel which operates as a clocking actuator to serially shift data from one memory cell to the next. The mechanical memory can be formed using conventional surface micromachining, and can be formed as either a nonvolatile memory or as a volatile memory.

  3. Mechanical memory

    DOEpatents

    Gilkey, Jeffrey C.; Duesterhaus, Michelle A.; Peter, Frank J.; Renn, Rosemarie A.; Baker, Michael S.

    2006-05-16

    A first-in-first-out (FIFO) microelectromechanical memory apparatus (also termed a mechanical memory) is disclosed. The mechanical memory utilizes a plurality of memory cells, with each memory cell having a beam which can be bowed in either of two directions of curvature to indicate two different logic states for that memory cell. The memory cells can be arranged around a wheel which operates as a clocking actuator to serially shift data from one memory cell to the next. The mechanical memory can be formed using conventional surface micromachining, and can be formed as either a nonvolatile memory or as a volatile memory.

  4. Induction of systemic and mucosal immunity and maintenance of its memory against influenza A virus by nasal vaccination using a new mucosal adjuvant SF-10 derived from pulmonary surfactant in young cynomolgus monkeys.

    PubMed

    Mizuno, Dai; Kimoto, Takashi; Sakai, Satoko; Takahashi, Etsuhisa; Kim, Hyejin; Kido, Hiroshi

    2016-04-01

    Induction of systemic and mucosal immunity and maintenance of its memory was investigated in 12 young male cynomolgus monkeys after intranasal instillation of flu vaccine using a new mucosal adjuvant SF-10 derived from pulmonary surfactant constituents. Split-product of influenza virus A/California/7/2009(H1N1)pdm hemagglutinin vaccine (HAv) at 15 μg with or without SF-10 and the adjuvant alone were instilled intranasally three times every 2 weeks. SF-10-adjuvanted HAv (SF-10-HAv) elicited significantly higher HAv-specific IgG and hemagglutinin inhibition (HI) titers in serum and HAv-specific secretory IgA and its neutralizing activities in nasal washes compared with HAv antigen and SF-10 alone. Significant cross-neutralizing activities of nasal washes after the third vaccination to several other H1N1 and H3N2 strains were observed. HI titers in serum and neutralizing activities in nasal washes reached peak levels at 6 weeks after initial vaccination, then gradually decreased after 10 weeks and returned to the baseline levels at 36 weeks. A single intranasal revaccination of SF-10-HAv at 36 weeks rapidly and significantly increased both immunity in serum and nasal washes compared with naïve monkeys. Revaccination by one or two doses achieved almost maximal immunity at 2 or 4 weeks after instillation. Statistically significant adverse effects (e.g., body weight loss, elevated body temperature, nasal discharge, change in peripheral blood leukocyte and platelet counts) were not observed for 2 weeks after vaccination of SF-10-HAv, HAv or SF-10 and also during the experimental period. These results in young monkey model suggest the potential of clinical use SF-10 for intranasal flu vaccine. PMID:26954466

  5. The evolving roles of memory immune cells in transplantation

    PubMed Central

    Chen, Wenhao; Ghobrial, Rafik M.; Li, Xian C.

    2015-01-01

    Memory cells are the products of immune responses but also exert significant impact on subsequent immunity and immune tolerance, thus placing them in a unique position in transplant research. Memory cells are heterogeneous, including not only memory T cells but also memory B cells and innate memory cells. Memory cells are a critical component of protective immunity against invading pathogens, especially in immunosuppressed patients, but they also mediate graft loss and tolerance resistance. Recent studies suggest that some memory cells unexpectedly act as regulatory cells, promoting rather than hindering transplant survival. This functional diversity makes therapeutic targeting of memory cells a challenging task in transplantation. In this article we highlight recent advances in our understanding of memory cells, focusing on diversity of memory cells and mechanisms involved in their induction and functions. We also provide a broad overview on the challenges and opportunities in targeting memory cells in the induction of transplant tolerance. PMID:26102615

  6. The role of stress during memory reactivation on intrusive memories.

    PubMed

    Cheung, Jessica; Garber, Benjamin; Bryant, Richard A

    2015-09-01

    Intrusive memories are unwanted recollections that maintain distress in psychological disorders. Increasing evidence suggests that memories that are reactivated through retrieval become temporarily vulnerable to environmental or pharmacological manipulation, including changes in levels of circulating stress hormones. This study investigated the influence of stress during memory reactivation of an emotionally arousing trauma film on subsequent intrusive memories. Three groups of participants (N=63) viewed a trauma film depicting a serious car accident at baseline. Two days later (Time 2), one group received a reactivation induction following a socially evaluated cold pressor test (SECPT; Stress/Reactivation condition), whilst the second group reactivated the memory after a control procedure (Reactivation condition). A third group underwent the SECPT but was not asked to reactivate memory of the trauma film (Stress condition). Two days later (Time 3), all participants received a surprise cued memory recall test and intrusions questionnaire which they completed online. Results showed that those in the Stress/Reactivation group had higher intrusions scores than the other two groups, suggesting that acute stress promotes intrusive memories only when the memory trace is reactivated shortly afterwards. Increased cortisol predicted enhanced intrusive experiences in the Stress/Reactivation condition but not in the other conditions. This pattern of results suggests that acute stress during the reactivation of emotional material impacts on involuntary emotional memories. These findings suggest a possible explanation for the mechanism underlying the maintenance of intrusive memories in clinical disorders.

  7. Memory Matters

    MedlinePlus

    ... different parts. Some of them are important for memory. The hippocampus (say: hih-puh-KAM-pus) is one of the more important parts of the brain that processes memories. Old information and new information, or memories, are ...

  8. Induction machine

    DOEpatents

    Owen, Whitney H.

    1980-01-01

    A polyphase rotary induction machine for use as a motor or generator utilizing a single rotor assembly having two series connected sets of rotor windings, a first stator winding disposed around the first rotor winding and means for controlling the current induced in one set of the rotor windings compared to the current induced in the other set of the rotor windings. The rotor windings may be wound rotor windings or squirrel cage windings.

  9. Boosting Tumor-Specific Immunity Using PDT

    PubMed Central

    Maeding, Nicole; Verwanger, Thomas; Krammer, Barbara

    2016-01-01

    Photodynamic therapy (PDT) is a cancer treatment with a long-standing history. It employs the application of nontoxic components, namely a light-sensitive photosensitizer and visible light, to generate reactive oxygen species (ROS). These ROS lead to tumor cell destruction, which is accompanied by the induction of an acute inflammatory response. This inflammatory process sends a danger signal to the innate immune system, which results in activation of specific cell types and release of additional inflammatory mediators. Activation of the innate immune response is necessary for subsequent induction of the adaptive arm of the immune system. This includes the priming of tumor-specific cytotoxic T lymphocytes (CTL) that have the capability to directly recognize and kill cells which display an altered self. The past decades have brought increasing appreciation for the importance of the generation of an adaptive immune response for long-term tumor control and induction of immune memory to combat recurrent disease. This has led to considerable effort to elucidate the immune effects PDT treatment elicits. In this review we deal with the progress which has been made during the past 20 years in uncovering the role of PDT in the induction of the tumor-specific immune response, with special emphasis on adaptive immunity. PMID:27782066

  10. Memory Palaces

    ERIC Educational Resources Information Center

    Wood, Marianne

    2007-01-01

    This article presents a lesson called Memory Palaces. A memory palace is a memory tool used to remember information, usually as visual images, in a sequence that is logical to the person remembering it. In his book, "In the Palaces of Memory", George Johnson calls them "...structure(s) for arranging knowledge. Lots of connections to language arts,…

  11. Unities in Inductive Reasoning. Technical Report No. 18.

    ERIC Educational Resources Information Center

    Sternberg, Robert J.; Gardner, Michael K.

    Two experiments were performed to study inductive reasoning as a set of thought processes that operates on the structure, as opposed to the content, of organized memory. The content of the reasoning consisted of inductions concerning the names of mammals, assumed to occupy a Euclidean space of three dimensions (size, ferocity, and humanness) in…

  12. LTP Induction Modifies Functional Relationship among Hippocampal Neurons

    ERIC Educational Resources Information Center

    Yun, Sung H.; Lee, Deok S.; Lee, Hyunjung; Baeg, Eun H.; Kim, Yun B.; Jung, Min W.

    2007-01-01

    To obtain evidence linking long-term potentiation (LTP) and memory, we examined whether LTP induction modifies functional relationship among neurons in the rat hippocampus. In contrast to neurons in low-frequency stimulated or AP5-treated slices, LTP induction altered "functional connectivity," as defined by the degree of synchronous firing, among…

  13. Human Influenza A Virus-Specific CD8+ T-Cell Response Is Long-lived.

    PubMed

    van de Sandt, Carolien E; Hillaire, Marine L B; Geelhoed-Mieras, Martina M; Osterhaus, Albert D M E; Fouchier, Ron A M; Rimmelzwaan, Guus F

    2015-07-01

    Animal and human studies have demonstrated the importance of influenza A virus (IAV)-specific CD8(+) cytotoxic T lymphocytes (CTLs) in heterosubtypic cross-protective immunity. Using peripheral blood mononuclear cells obtained intermittently from healthy HLA-typed blood donors between 1999 and 2012, we were able to demonstrate that IAV-specific CTLs are long-lived. Intercurrent IAV infections transiently increase the frequency of functionally distinct subsets of IAV-specific CTLs, in particular effector and effector memory T cells.

  14. Vicarious memories.

    PubMed

    Pillemer, David B; Steiner, Kristina L; Kuwabara, Kie J; Thomsen, Dorthe Kirkegaard; Svob, Connie

    2015-11-01

    People not only have vivid memories of their own personal experiences, but also vicarious memories of events that happened to other people. To compare the phenomenological and functional qualities of personal and vicarious memories, college students described a specific past event that they had recounted to a parent or friend, and also an event that a friend or parent had recounted to them. Although ratings of memory vividness, emotional intensity, visualization, and physical reactions were higher for personal than for vicarious memories, the overall pattern of ratings was similar. Participants' ratings also indicated that vicarious memories serve many of the same life functions as personal memories, although at lower levels of intensity. The findings suggest that current conceptions of autobiographical memory, which focus on past events that happened directly to the self, should be expanded to include detailed mental representations of specific past events that happened to other people.

  15. Memory Dysfunction

    PubMed Central

    Matthews, Brandy R.

    2015-01-01

    Purpose of Review: This article highlights the dissociable human memory systems of episodic, semantic, and procedural memory in the context of neurologic illnesses known to adversely affect specific neuroanatomic structures relevant to each memory system. Recent Findings: Advances in functional neuroimaging and refinement of neuropsychological and bedside assessment tools continue to support a model of multiple memory systems that are distinct yet complementary and to support the potential for one system to be engaged as a compensatory strategy when a counterpart system fails. Summary: Episodic memory, the ability to recall personal episodes, is the subtype of memory most often perceived as dysfunctional by patients and informants. Medial temporal lobe structures, especially the hippocampal formation and associated cortical and subcortical structures, are most often associated with episodic memory loss. Episodic memory dysfunction may present acutely, as in concussion; transiently, as in transient global amnesia (TGA); subacutely, as in thiamine deficiency; or chronically, as in Alzheimer disease. Semantic memory refers to acquired knowledge about the world. Anterior and inferior temporal lobe structures are most often associated with semantic memory loss. The semantic variant of primary progressive aphasia (svPPA) is the paradigmatic disorder resulting in predominant semantic memory dysfunction. Working memory, associated with frontal lobe function, is the active maintenance of information in the mind that can be potentially manipulated to complete goal-directed tasks. Procedural memory, the ability to learn skills that become automatic, involves the basal ganglia, cerebellum, and supplementary motor cortex. Parkinson disease and related disorders result in procedural memory deficits. Most memory concerns warrant bedside cognitive or neuropsychological evaluation and neuroimaging to assess for specific neuropathologies and guide treatment. PMID:26039844

  16. Memory protection

    NASA Technical Reports Server (NTRS)

    Denning, Peter J.

    1988-01-01

    Accidental overwriting of files or of memory regions belonging to other programs, browsing of personal files by superusers, Trojan horses, and viruses are examples of breakdowns in workstations and personal computers that would be significantly reduced by memory protection. Memory protection is the capability of an operating system and supporting hardware to delimit segments of memory, to control whether segments can be read from or written into, and to confine accesses of a program to its segments alone. The absence of memory protection in many operating systems today is the result of a bias toward a narrow definition of performance as maximum instruction-execution rate. A broader definition, including the time to get the job done, makes clear that cost of recovery from memory interference errors reduces expected performance. The mechanisms of memory protection are well understood, powerful, efficient, and elegant. They add to performance in the broad sense without reducing instruction execution rate.

  17. Quantum memory Quantum memory

    NASA Astrophysics Data System (ADS)

    Le Gouët, Jean-Louis; Moiseev, Sergey

    2012-06-01

    Interaction of quantum radiation with multi-particle ensembles has sparked off intense research efforts during the past decade. Emblematic of this field is the quantum memory scheme, where a quantum state of light is mapped onto an ensemble of atoms and then recovered in its original shape. While opening new access to the basics of light-atom interaction, quantum memory also appears as a key element for information processing applications, such as linear optics quantum computation and long-distance quantum communication via quantum repeaters. Not surprisingly, it is far from trivial to practically recover a stored quantum state of light and, although impressive progress has already been accomplished, researchers are still struggling to reach this ambitious objective. This special issue provides an account of the state-of-the-art in a fast-moving research area that makes physicists, engineers and chemists work together at the forefront of their discipline, involving quantum fields and atoms in different media, magnetic resonance techniques and material science. Various strategies have been considered to store and retrieve quantum light. The explored designs belong to three main—while still overlapping—classes. In architectures derived from photon echo, information is mapped over the spectral components of inhomogeneously broadened absorption bands, such as those encountered in rare earth ion doped crystals and atomic gases in external gradient magnetic field. Protocols based on electromagnetic induced transparency also rely on resonant excitation and are ideally suited to the homogeneous absorption lines offered by laser cooled atomic clouds or ion Coulomb crystals. Finally off-resonance approaches are illustrated by Faraday and Raman processes. Coupling with an optical cavity may enhance the storage process, even for negligibly small atom number. Multiple scattering is also proposed as a way to enlarge the quantum interaction distance of light with matter. The

  18. Declarative memory.

    PubMed

    Riedel, Wim J; Blokland, Arjan

    2015-01-01

    Declarative Memory consists of memory for events (episodic memory) and facts (semantic memory). Methods to test declarative memory are key in investigating effects of potential cognition-enhancing substances--medicinal drugs or nutrients. A number of cognitive performance tests assessing declarative episodic memory tapping verbal learning, logical memory, pattern recognition memory, and paired associates learning are described. These tests have been used as outcome variables in 34 studies in humans that have been described in the literature in the past 10 years. Also, the use of episodic tests in animal research is discussed also in relation to the drug effects in these tasks. The results show that nutritional supplementation of polyunsaturated fatty acids has been investigated most abundantly and, in a number of cases, but not all, show indications of positive effects on declarative memory, more so in elderly than in young subjects. Studies investigating effects of registered anti-Alzheimer drugs, cholinesterase inhibitors in mild cognitive impairment, show positive and negative effects on declarative memory. Studies mainly carried out in healthy volunteers investigating the effects of acute dopamine stimulation indicate enhanced memory consolidation as manifested specifically by better delayed recall, especially at time points long after learning and more so when drug is administered after learning and if word lists are longer. The animal studies reveal a different picture with respect to the effects of different drugs on memory performance. This suggests that at least for episodic memory tasks, the translational value is rather poor. For the human studies, detailed parameters of the compositions of word lists for declarative memory tests are discussed and it is concluded that tailored adaptations of tests to fit the hypothesis under study, rather than "off-the-shelf" use of existing tests, are recommended. PMID:25977084

  19. CCR4 is critically involved in effective antitumor immunity in mice bearing intradermal B16 melanoma.

    PubMed

    Matsuo, Kazuhiko; Itoh, Tatsuki; Koyama, Atsushi; Imamura, Reira; Kawai, Shiori; Nishiwaki, Keiji; Oiso, Naoki; Kawada, Akira; Yoshie, Osamu; Nakayama, Takashi

    2016-08-01

    CCR4 is a major chemokine receptor expressed by Treg cells and Th17 cells. While Treg cells are known to suppress antitumor immunity, Th17 cells have recently been shown to enhance the induction of antitumor cytotoxic T lymphocytes. Here, CCR4-deficient mice displayed enhanced tumor growth upon intradermal inoculation of B16-F10 melanoma cells. In CCR4-deficient mice, while IFN-γ+CD8+ effector T cells were decreased in tumor sites, IFN-γ+CD8+ T cells and Th17 cells were decreased in regional lymph nodes. In wild-type mice, CD4+IL-17A+ cells, which were identified as CCR4+CD44+ memory Th17, were found to be clustered around dendritic cells expressing MDC/CCL22, a ligand for CCR4, in regional lymph nodes. Compound 22, a CCR4 antagonist, also enhanced tumor growth and decreased Th17 cells in regional lymph nodes in tumor-bearing mice treated with Dacarbazine. In contrast, CCR6 deficiency did not affect the tumor growth and the numbers of Th17 cells in regional lymph nodes. These findings indicate that CCR4 is critically involved in regional lymph node DC-Th17 cell interactions that are necessary for Th17 cell-mediated induction of antitumor CD8+ effector T cells in mice bearing B16 melanoma. PMID:27132989

  20. Development of inductive generalization with familiar categories.

    PubMed

    Fisher, Anna V; Godwin, Karrie E; Matlen, Bryan J

    2015-10-01

    Inductive generalization is ubiquitous in human cognition. In the developmental literature, two different theoretical accounts of this important process have been proposed: a naïve theory account and a similarity-based account. However, a number of recent findings cannot be explained within the existing theoretical accounts. We describe a revised version of the similarity-based account of inductive generalization with familiar categories. We tested the novel predictions of this account in two reported studies with 4-year-old children (N = 57). The reported studies include the first short-term longitudinal investigation of the development of children's induction with familiar categories, and it is the first study to explore the role of individual differences in semantic organization, general intelligence, working memory, and inhibition in children's induction.

  1. Induction of CD4(+) T cell-dependent CD8(+) type 1 responses in humans by a malaria DNA vaccine.

    PubMed

    Wang, R; Epstein, J; Baraceros, F M; Gorak, E J; Charoenvit, Y; Carucci, D J; Hedstrom, R C; Rahardjo, N; Gay, T; Hobart, P; Stout, R; Jones, T R; Richie, T L; Parker, S E; Doolan, D L; Norman, J; Hoffman, S L

    2001-09-11

    We assessed immunogenicity of a malaria DNA vaccine administered by needle i.m. or needleless jet injection [i.m. or i.m./intradermally (i.d.)] in 14 volunteers. Antigen-specific IFN-gamma responses were detected by enzyme-linked immunospot (ELISPOT) assays in all subjects to multiple 9- to 23-aa peptides containing class I and/or class II restricted epitopes, and were dependent on both CD8(+) and CD4(+) T cells. Overall, frequency of response was significantly greater after i.m. jet injection. CD8(+)-dependent cytotoxic T lymphocytes (CTL) were detected in 8/14 volunteers. Demonstration in humans of elicitation of the class I restricted IFN-gamma responses we believe necessary for protection against the liver stage of malaria parasites brings us closer to an effective malaria vaccine.

  2. Virtual memory

    NASA Technical Reports Server (NTRS)

    Denning, P. J.

    1986-01-01

    Virtual memory was conceived as a way to automate overlaying of program segments. Modern computers have very large main memories, but need automatic solutions to the relocation and protection problems. Virtual memory serves this need as well and is thus useful in computers of all sizes. The history of the idea is traced, showing how it has become a widespread, little noticed feature of computers today.

  3. CCD Memory

    NASA Technical Reports Server (NTRS)

    Janesick, James R.; Elliot, Tom; Norris, Dave; Vescelus, Fred

    1987-01-01

    CCD memory device yields over 6.4 x 10 to the eighth power levels of information on single chip. Charge-coupled device (CCD) demonstrated to operate as either read-only-memory (ROM) or photon-programmable memory with capacity of 640,000 bits, with each bit capable of being weighted to more than 1,000 discrete analog levels. Larger memory capacities now possible using proposed approach in conjunction with CCD's now being fabricated, which yield over 4 x 10 to the ninth power discrete levels of information on single chip.

  4. Memory systems.

    PubMed

    Eichenbaum, Howard

    2010-07-01

    The idea that there are multiple memory systems can be traced to early philosophical considerations and introspection. However, the early experimental work considered memory a unitary phenomenon and focused on finding the mechanism upon which memory is based. A full reconciliation of debates about that mechanism, and a coincidental rediscovery of the idea of multiple memory systems, emerged from studies in the cognitive neuroscience of memory. This research has identified three major forms of memory that have distinct operating principles and are supported by different brain systems. These include: (1) a cortical-hippocampal circuit that mediates declarative memory, our capacity to recollect facts and events; (2) procedural memory subsystems involving a cortical-striatal circuit that mediates habit formation and a brainstem-cerebellar circuit that mediates sensorimotor adaptations; and (3) a circuit involving subcortical and cortical pathways through the amygdala that mediates the attachment of affective status and emotional responses to previously neutral stimuli. Copyright © 2010 John Wiley & Sons, Ltd. For further resources related to this article, please visit the WIREs website.

  5. Collaging Memories

    ERIC Educational Resources Information Center

    Wallach, Michele

    2011-01-01

    Even middle school students can have memories of their childhoods, of an earlier time. The art of Romare Bearden and the writings of Paul Auster can be used to introduce ideas about time and memory to students and inspire works of their own. Bearden is an exceptional role model for young artists, not only because of his astounding art, but also…

  6. Episodic Memories

    ERIC Educational Resources Information Center

    Conway, Martin A.

    2009-01-01

    An account of episodic memories is developed that focuses on the types of knowledge they represent, their properties, and the functions they might serve. It is proposed that episodic memories consist of "episodic elements," summary records of experience often in the form of visual images, associated to a "conceptual frame" that provides a…

  7. Failed induction of labor.

    PubMed

    Schoen, Corina; Navathe, Reshama

    2015-10-01

    Induction of labor will affect almost a quarter of all pregnancies, but historically there has been no generally accepted definition of failed induction of labor. Only recently have studies analyzed the lengths of latent labor that are associated with successful labor induction ending in a vaginal delivery, and recommendations for uniformity in the diagnosis of failed induction have largely resulted from this data. This review assesses the most recent and inclusive definition for failed induction, risk factors associated with failure, complications, and special populations that may be at risk for a failed induction.

  8. Memory conformity affects inaccurate memories more than accurate memories.

    PubMed

    Wright, Daniel B; Villalba, Daniella K

    2012-01-01

    After controlling for initial confidence, inaccurate memories were shown to be more easily distorted than accurate memories. In two experiments groups of participants viewed 50 stimuli and were then presented with these stimuli plus 50 fillers. During this test phase participants reported their confidence that each stimulus was originally shown. This was followed by computer-generated responses from a bogus participant. After being exposed to this response participants again rated the confidence of their memory. The computer-generated responses systematically distorted participants' responses. Memory distortion depended on initial memory confidence, with uncertain memories being more malleable than confident memories. This effect was moderated by whether the participant's memory was initially accurate or inaccurate. Inaccurate memories were more malleable than accurate memories. The data were consistent with a model describing two types of memory (i.e., recollective and non-recollective memories), which differ in how susceptible these memories are to memory distortion.

  9. Feelings Without Memory in Alzheimer Disease

    PubMed Central

    Guzmán-Vélez, Edmarie; Feinstein, Justin S.

    2014-01-01

    Background: Patients with Alzheimer disease (AD) typically have impaired declarative memory as a result of hippocampal damage early in the disease. Far less is understood about AD’s effect on emotion. Objective: We investigated whether feelings of emotion can persist in patients with AD, even after their declarative memory for what caused the feelings has faded. Methods: A sample of 17 patients with probable AD and 17 healthy comparison participants (case-matched for age, sex, and education) underwent 2 separate emotion induction procedures in which they watched film clips intended to induce feelings of sadness or happiness. We collected real-time emotion ratings at baseline and at 3 post-induction time points, and we administered a test of declarative memory shortly after each induction. Results: As expected, the patients with AD had severely impaired declarative memory for both the sad and happy films. Despite their memory impairment, the patients continued to report elevated levels of sadness and happiness that persisted well beyond their memory for the films. This outcome was especially prominent after the sadness induction, with sustained elevations in sadness lasting for more than 30 minutes, even in patients with no conscious recollection for the films. Conclusions: These findings indicate that patients with AD can experience prolonged states of emotion that persist well beyond the patients’ memory for the events that originally caused the emotion. The preserved emotional life evident in patients with AD has important implications for their management and care, and highlights the need for caretakers to foster positive emotional experiences. PMID:25237742

  10. Fear Memory.

    PubMed

    Izquierdo, Ivan; Furini, Cristiane R G; Myskiw, Jociane C

    2016-04-01

    Fear memory is the best-studied form of memory. It was thoroughly investigated in the past 60 years mostly using two classical conditioning procedures (contextual fear conditioning and fear conditioning to a tone) and one instrumental procedure (one-trial inhibitory avoidance). Fear memory is formed in the hippocampus (contextual conditioning and inhibitory avoidance), in the basolateral amygdala (inhibitory avoidance), and in the lateral amygdala (conditioning to a tone). The circuitry involves, in addition, the pre- and infralimbic ventromedial prefrontal cortex, the central amygdala subnuclei, and the dentate gyrus. Fear learning models, notably inhibitory avoidance, have also been very useful for the analysis of the biochemical mechanisms of memory consolidation as a whole. These studies have capitalized on in vitro observations on long-term potentiation and other kinds of plasticity. The effect of a very large number of drugs on fear learning has been intensively studied, often as a prelude to the investigation of effects on anxiety. The extinction of fear learning involves to an extent a reversal of the flow of information in the mentioned structures and is used in the therapy of posttraumatic stress disorder and fear memories in general. PMID:26983799

  11. Fear Memory.

    PubMed

    Izquierdo, Ivan; Furini, Cristiane R G; Myskiw, Jociane C

    2016-04-01

    Fear memory is the best-studied form of memory. It was thoroughly investigated in the past 60 years mostly using two classical conditioning procedures (contextual fear conditioning and fear conditioning to a tone) and one instrumental procedure (one-trial inhibitory avoidance). Fear memory is formed in the hippocampus (contextual conditioning and inhibitory avoidance), in the basolateral amygdala (inhibitory avoidance), and in the lateral amygdala (conditioning to a tone). The circuitry involves, in addition, the pre- and infralimbic ventromedial prefrontal cortex, the central amygdala subnuclei, and the dentate gyrus. Fear learning models, notably inhibitory avoidance, have also been very useful for the analysis of the biochemical mechanisms of memory consolidation as a whole. These studies have capitalized on in vitro observations on long-term potentiation and other kinds of plasticity. The effect of a very large number of drugs on fear learning has been intensively studied, often as a prelude to the investigation of effects on anxiety. The extinction of fear learning involves to an extent a reversal of the flow of information in the mentioned structures and is used in the therapy of posttraumatic stress disorder and fear memories in general.

  12. Is external memory memory? Biological memory and extended mind.

    PubMed

    Michaelian, Kourken

    2012-09-01

    Clark and Chalmers (1998) claim that an external resource satisfying the following criteria counts as a memory: (1) the agent has constant access to the resource; (2) the information in the resource is directly available; (3) retrieved information is automatically endorsed; (4) information is stored as a consequence of past endorsement. Research on forgetting and metamemory shows that most of these criteria are not satisfied by biological memory, so they are inadequate. More psychologically realistic criteria generate a similar classification of standard putative external memories, but the criteria still do not capture the function of memory. An adequate account of memory function, compatible with its evolution and its roles in prospection and imagination, suggests that external memory performs a function not performed by biological memory systems. External memory is thus not memory. This has implications for: extended mind theorizing, ecological validity of memory research, the causal theory of memory.

  13. Sequential inductive learning

    SciTech Connect

    Gratch, J.

    1996-12-31

    This article advocates a new model for inductive learning. Called sequential induction, it helps bridge classical fixed-sample learning techniques (which are efficient but difficult to formally characterize), and worst-case approaches (which provide strong statistical guarantees but are too inefficient for practical use). Learning proceeds as a sequence of decisions which are informed by training data. By analyzing induction at the level of these decisions, and by utilizing the only enough data to make each decision, sequential induction provides statistical guarantees but with substantially less data than worst-case methods require. The sequential inductive model is also useful as a method for determining a sufficient sample size for inductive learning and as such, is relevant to learning problems where the preponderance of data or the cost of gathering data precludes the use of traditional methods.

  14. Spacing and Induction: Application to Exemplars Presented as Auditory and Visual Text

    ERIC Educational Resources Information Center

    Zulkiply, Norehan; McLean, John; Burt, Jennifer S.; Bath, Debra

    2012-01-01

    It is an established finding that spacing repetitions generally facilitates memory for the repeated events. However, the effect of spacing of exemplars on inductive learning is not really known. Two experiments using textual material were conducted to investigate the effect of spacing on induction. Experiment 1 and 2 extended the generality of…

  15. Retracing Memories

    ERIC Educational Resources Information Center

    Harrison, David L.

    2005-01-01

    There are plenty of paths to poetry but few are as accessible as retracing ones own memories. When students are asked to write about something they remember, they are given them the gift of choosing from events that are important enough to recall. They remember because what happened was funny or scary or embarrassing or heartbreaking or silly.…

  16. Fueling Memories

    PubMed Central

    Powell, Jonathan D.; Pollizzi, Kristen

    2012-01-01

    A hallmark of the adaptive immune response is rapid and robust activation upon rechallenge. In the current issue of Immunity van der Windt et al. (2012) provide an important link between mitochondrial respiratory capacity and the development of CD8+ T cell memory. PMID:22284413

  17. Memory Loss

    ERIC Educational Resources Information Center

    Cassebaum, Anne

    2011-01-01

    In four decades of teaching college English, the author has watched many good teaching jobs morph into second-class ones. Worse, she has seen the memory and then the expectation of teaching jobs with decent status, security, and salary depart along with principles and collegiality. To help reverse this downward spiral, she contends that what is…

  18. Wnt signaling inhibits CTL memory programming.

    PubMed

    Xiao, Zhengguo; Sun, Zhifeng; Smyth, Kendra; Li, Lei

    2013-12-01

    Induction of functional CTLs is one of the major goals for vaccine development and cancer therapy. Inflammatory cytokines are critical for memory CTL generation. Wnt signaling is important for CTL priming and memory formation, but its role in cytokine-driven memory CTL programming is unclear. We found that wnt signaling inhibited IL-12-driven CTL activation and memory programming. This impaired memory CTL programming was attributed to up-regulation of eomes and down-regulation of T-bet. Wnt signaling suppressed the mTOR pathway during CTL activation, which was different to its effects on other cell types. Interestingly, the impaired memory CTL programming by wnt was partially rescued by mTOR inhibitor rapamycin. In conclusion, we found that crosstalk between wnt and the IL-12 signaling inhibits T-bet and mTOR pathways and impairs memory programming which can be recovered in part by rapamycin. In addition, direct inhibition of wnt signaling during CTL activation does not affect CTL memory programming. Therefore, wnt signaling may serve as a new tool for CTL manipulation in autoimmune diseases and immune therapy for certain cancers.

  19. Induction: Making the Leap

    ERIC Educational Resources Information Center

    Ling, Lorraine M.

    2009-01-01

    This article provides a critical examination of a variety of approaches to induction focusing especially upon Australia and other Pacific Rim countries. The question of the purposes induction serves for graduate teachers, experienced teachers and education systems is addressed in terms of whether it is a technical exercise which preserves the…

  20. Ion Induction Accelerators

    NASA Astrophysics Data System (ADS)

    Barnard, John J.; Horioka, Kazuhiko

    The description of beams in RF and induction accelerators share many common features. Likewise, there is considerable commonality between electron induction accelerators (see Chap. 7) and ion induction accelerators. However, in contrast to electron induction accelerators, there are fewer ion induction accelerators that have been operated as application-driven user facilities. Ion induction accelerators are envisioned for applications (see Chap. 10) such as Heavy Ion Fusion (HIF), High Energy Density Physics (HEDP), and spallation neutron sources. Most ion induction accelerators constructed to date have been limited scale facilities built for feasibility studies for HIF and HEDP where a large numbers of ions are required on target in short pulses. Because ions are typically non-relativistic or weakly relativistic in much of the machine, space-charge effects can be of crucial importance. This contrasts the situation with electron machines, which are usually strongly relativistic leading to weaker transverse space-charge effects and simplified longitudinal dynamics. Similarly, the bunch structure of ion induction accelerators relative to RF machines results in significant differences in the longitudinal physics.

  1. Induction Programs that Work

    ERIC Educational Resources Information Center

    Gilles, Carol; Davis, Barbara; McGlamery, Sheryl

    2009-01-01

    The Comprehensive Teacher Induction Consortium, a group of similar teacher induction programs, has used a highly successful model for over 15 years. Four crucial aspects of that model are a full year of mentored support for first-year teachers, coursework leading to a master's degree, opportunities for sharing with other beginning teachers, and…

  2. Does Stress Enhance or Impair Memory Consolidation?

    PubMed Central

    Trammell, Janet P.; Clore, Gerald L.

    2014-01-01

    Three experiments examined the hypothesis that stress-induced arousal enhances long term memory for experiences associated with an arousing events. Contrary to expectations, in each experiment exposure to a stressor (arm immersion in ice water) interfered with, rather than enhanced, long term memory for associated material. Despite varying the stimuli (words, pictures), their emotional value (positive, negative, neutral), the time between learning and stress inductions (0 to 1 minute), and opportunities for post-learning rehearsal, each experiment produced a significant reversal of the hypothesized effect. That is, in each experiment, exposure to a stressor interfered with, rather than enhanced, long term memory for associated material. We conclude that the relationship between stress and memory consolidation is more bounded than previously believed. PMID:23895111

  3. Direct reading inductance meter

    NASA Technical Reports Server (NTRS)

    Kolby, R. B. (Inventor)

    1977-01-01

    A direct reading inductance meter comprised of a crystal oscillator and an LC tuned oscillator is presented. The oscillators function respectively to generate a reference frequency, f(r), and to generate an initial frequency, f(0), which when mixed produce a difference equal to zero. Upon connecting an inductor of small unknown value in the LC circuit to change its resonant frequency to f(x), a difference frequency (f(r)-f(x)) is produced that is very nearly a linear function of the inductance of the inductor. The difference frequency is measured and displayed on a linear scale in units of inductance.

  4. The induction motor

    NASA Astrophysics Data System (ADS)

    Redinz, José Arnaldo

    2015-09-01

    We obtain analytical expressions for the torques and angular speed of an induction motor with a simple geometry, resembling the geometry of the first induction motor investigated by Arago in 1824. The rotor is a conducting disc rotating between the magnetic poles of two off-axis solenoids, displaced in space by 90^\\circ from each other. We apply our results to discuss a theory for the ubiquitous electromechanical watt-hour meter. For comparison of the theoretical result for the angular speed with measurements, we propose a simple experiment in which an induction motor with an aluminum disc rotor is constructed.

  5. Electromagnetic induction in Australia

    NASA Astrophysics Data System (ADS)

    Lilley, F. E. M.

    Electromagnetic induction at the terrestrial surface is a general and ubiquitous process. This note, which covers research on the subject in Australia, reflects the writer's own interest and refers particularly to induction by natural source fields in the period range of 1 minute to 1 day.Such source fields arise external to Earth, in the ionosphere and beyond, in the magnetosphere. The process of electromagnetic induction by these fields involves the flow through Earth of tens of thousands of amperes, over scale lengths of thousands of kilometers.

  6. Mechanism of induction of class I major histocompatibility antigen expression by murine leukemia virus.

    PubMed

    Faller, D V; Wilson, L D; Flyer, D C

    1988-03-01

    Alterations in expression of major histocompatibility complex (MHC) antigens on tumor cells clearly correlate with the tumorgenicity and metastatic potential of those cells. These changes in the biological behavior of the tumor cells are presumably secondary to resulting changes in their susceptibility to immune recognition and destruction. Murine leukemia viruses (MuLV) exert regulatory effects on class I genes of the MHC locus. MuLV infection results in substantial increases in cell surface expression of all three class I MHC antigens. These viral effects on MHC antigen expression profoundly influence immune-mediated interaction with the infected cells, as assessed by cytotoxic T lymphocyte recognition and killing. Control of class I MHC and beta-2 microglobulin genes by MuLV takes place via a trans-acting molecular mechanism. MuLV controls expression of widely separated endogenous cellular MHC genes, transfected xenogeneic class I MHC genes, and unintegrated chimeric genes consisting of fragments of class I MHC genes linked to a bacterial reporter gene. These findings indicate that MuLV exerts its effects on MHC expression via a trans mechanism. The MuLV-responsive sequences on the MHC genes appear to lie within 1.2 kilobases upstream of the initiation codon for those genes.

  7. Induction of Inhibitory Receptors on T Cells During Plasmodium vivax Malaria Impairs Cytokine Production.

    PubMed

    Costa, Pedro A C; Leoratti, Fabiana M S; Figueiredo, Maria M; Tada, Mauro S; Pereira, Dhelio B; Junqueira, Caroline; Soares, Irene S; Barber, Daniel L; Gazzinelli, Ricardo T; Antonelli, Lis R V

    2015-12-15

    The function and regulation of the immune response triggered during malaria is complex and poorly understood, and there is a particular paucity of studies conducted in humans infected with Plasmodium vivax. While it has been proposed that T-cell-effector responses are crucial for protection against blood-stage malaria in mice, the mechanisms behind this in humans remain poorly understood. Experimental models of malaria have shown that the regulatory molecules, cytotoxic T-lymphocyte attenuator-4 (CTLA-4), lymphocyte activation gene-3 (LAG-3), and programmed death-1 (PD-1) are involved in the functional impairment of T cells during infection. Our goal was to define the role of these molecules during P. vivax malaria. We demonstrate that infection triggers the expression of regulatory molecules on T cells. The pattern of expression differs in CD4(+) and CD8(+) T cells. Higher frequencies of CD4(+) express more than 1 regulatory molecule compared to CD8(+) T cells. Moreover, lower proportions of CD4(+) T cells coexpress regulatory molecules, but are still able to proliferate. Importantly, simultaneously blockade of the CLTA-4, PD-1, and T-cell immunoglobulin and mucin-3 signaling restores the cytokine production by antigen-specific cells. These data support the hypothesis that upregulation of inhibitory receptors on T cells during P. vivax malaria impairs parasite-specific T-cell effector function.

  8. Induction of Broad Cytotoxic T Cells by Protective DNA Vaccination Against Marburg and Ebola

    PubMed Central

    Shedlock, Devon J; Aviles, Jenna; Talbott, Kendra T; Wong, Gary; Wu, Stephan J; Villarreal, Daniel O; Myles, Devin JF; Croyle, Maria A; Yan, Jian; Kobinger, Gary P; Weiner, David B

    2013-01-01

    Marburg and Ebola hemorrhagic fevers have been described as the most virulent viral diseases known to man due to associative lethality rates of up to 90%. Death can occur within days to weeks of exposure and there is currently no licensed vaccine or therapeutic. Recent evidence suggests an important role for antiviral T cells in conferring protection, but little detailed analysis of this response as driven by a protective vaccine has been reported. We developed a synthetic polyvalent-filovirus DNA vaccine against Marburg marburgvirus (MARV), Zaire ebolavirus (ZEBOV), and Sudan ebolavirus (SUDV). Preclinical efficacy studies were performed in guinea pigs and mice using rodent-adapted viruses, whereas murine T-cell responses were extensively analyzed using a novel modified assay described herein. Vaccination was highly potent, elicited robust neutralizing antibodies, and completely protected against MARV and ZEBOV challenge. Comprehensive T-cell analysis revealed cytotoxic T lymphocytes (CTLs) of great magnitude, epitopic breadth, and Th1-type marker expression. This model provides an important preclinical tool for studying protective immune correlates that could be applied to existing platforms. Data herein support further evaluation of this enhanced gene-based approach in nonhuman primate studies for in depth analyses of T-cell epitopes in understanding protective efficacy. PMID:23670573

  9. Induction of specific cytotoxic lymphocytes in mice vaccinated with Brucella abortus RB51.

    PubMed

    He, Y; Vemulapalli, R; Zeytun, A; Schurig, G G

    2001-09-01

    A safe, more sensitive, nonradioactive, neutral red uptake assay was adopted to replace the traditional 51Cr release assay for detection of Brucella-specific cytotoxic T lymphocyte (CTL) activity. Our studies indicated that Brucella abortus strain RB51 vaccination of mice induced specific CTLs against both strain RB51- and strain 2308-infected J774.A1 macrophages but not against Listeria monocytogenes-infected J774.A1 cells. The antigen-specific cytotoxic activity was exerted by T lymphocytes but not by NK cells. CD3+ CD4+ T cells secreted the highest level of gamma interferon (IFN-gamma) and were able to exert a low but significant level of specific lysis of Brucella-infected macrophages. They also exerted a low level of nonspecific lysis of noninfected macrophages. In contrast, CD3+ CD8+ T cells secreted low levels of IFN-gamma but demonstrated high levels of specific lysis of Brucella-infected macrophages with no nonspecific lysis. These findings indicate that B. abortus strain RB51 vaccination of mice induces specific CTLs and suggest that CD3+ CD4+ and CD3+ CD8+ T cells play a synergistic role in the anti-Brucella activity.

  10. Constructive episodic simulation: Dissociable effects of a specificity induction on remembering, imagining, and describing in young and older adults

    PubMed Central

    Madore, Kevin P.; Gaesser, Brendan; Schacter, Daniel L.

    2013-01-01

    According to the constructive episodic simulation hypothesis (Schacter & Addis, 2007), both remembered past and imagined future events rely heavily on episodic memory. An alternative hypothesis is that observed similarities between remembering and imagining reflect the influence of broader factors such as descriptive ability, narrative style, or inhibitory control. We attempted to distinguish between these two hypotheses by examining the impact of an episodic specificity induction on memory, imagination, and picture description in young and older adults. In Experiment 1, participants received the specificity induction or a control induction prior to the memory, imagination, and description tasks. Older adults provided fewer internal (i.e., episodic) and more external (i.e., semantic) details than young adults across the three tasks irrespective of induction. Critically, however, the specificity induction selectively increased internal but not external details for memory and imagination in both age groups compared with the control induction. By contrast, the induction did not affect internal (or external) details for picture description. Experiment 2 replicated these results in young adults using a different control induction. Our findings point to a dissociation between episodic processes involved in memory and imagination and non-episodic processes involved in picture description. PMID:24188466

  11. Simultaneous approach using systemic, mucosal and transcutaneous routes of immunization for development of protective HIV-1 vaccines.

    PubMed

    Belyakov, I M; Ahlers, J D

    2011-01-01

    Mucosal tissues are major sites of HIV entry and initial infection. Induction of a local mucosal cytotoxic T lymphocyte response is considered an important goal in developing an effective HIV vaccine. In addition, activation and recruitment of memory CD4(+) and CD8(+) T cells in systemic lymphoid circulation to mucosal effector sites might provide the firewall needed to prevent virus spread. Therefore a vaccine that generates CD4(+) and CD8(+) responses in both mucosal and systemic tissues might be required for protection against HIV. However, optimal routes and number of vaccinations required for the generation of long lasting CD4(+) and CD8(+) CTL effector and memory responses are not well understood especially for mucosal T cells. A number of studies looking at protective immune responses against diverse mucosal pathogens have shown that mucosal vaccination is necessary to induce a compartmentalized immune response including maximum levels of mucosal high-avidity CD8(+) CTL, antigen specific mucosal antibodies titers (especially sIgA), as well as induction of innate anti-viral factors in mucosa tissue. Immune responses are detectable at mucosal sites after systemic delivery of vaccine, and prime boost regimens can amplify the magnitude of immune responses in mucosal sites and in systemic lymphoid tissues. We believe that the most optimal mucosal and systemic HIV/SIV specific protective immune responses and innate factors might best be achieved by simultaneous mucosal and systemic prime and boost vaccinations. Similar principals of vaccination may be applied for vaccine development against cancer and highly invasive pathogens that lead to chronic infection. PMID:21824096

  12. Induction heating coupler

    NASA Technical Reports Server (NTRS)

    Fox, Robert L. (Inventor); Copeland, Carl E. (Inventor); Swaim, Robert J. (Inventor); Coultrip, Robert H. (Inventor); Johnston, David F. (Inventor); Phillips, W. Morris (Inventor); Johnson, Samuel D. (Inventor); Dinkins, James R. (Inventor); Buckley, John D. (Inventor)

    1994-01-01

    An induction heating device includes a handle having a hollow interior and two opposite ends, a wrist connected to one end of the handle, a U-shaped pole piece having two spaced apart ends, a tank circuit including an induction coil wrapped around the pole piece and a capacitor connected to the induction coil, a head connected to the wrist and including a housing for receiving the U-shaped pole piece, the two spaced apart ends of the pole piece extending outwardely beyond the housing, and a power source connected to the tank circuit. When the tank circuit is energized and a susceptor is placed in juxtaposition to the ends of the U-shaped pole piece, the susceptor is heated by induction heating due to magnetic flux passing between the two ends of the pole piece.

  13. Induction melter apparatus

    DOEpatents

    Roach, Jay A [Idaho Falls, ID; Richardson, John G [Idaho Falls, ID; Raivo, Brian D [Idaho Falls, ID; Soelberg, Nicholas R [Idaho Falls, ID

    2008-06-17

    Apparatus and methods of operation are provided for a cold-crucible-induction melter for vitrifying waste wherein a single induction power supply may be used to effect a selected thermal distribution by independently energizing at least two inductors. Also, a bottom drain assembly may be heated by an inductor and may include an electrically resistive heater. The bottom drain assembly may be cooled to solidify molten material passing therethrough to prevent discharge of molten material therefrom. Configurations are provided wherein the induction flux skin depth substantially corresponds with the central longitudinal axis of the crucible. Further, the drain tube may be positioned within the induction flux skin depth in relation to material within the crucible or may be substantially aligned with a direction of flow of molten material within the crucible. An improved head design including four shells forming thermal radiation shields and at least two gas-cooled plenums is also disclosed.

  14. Enhancing Induction Coil Reliability

    NASA Astrophysics Data System (ADS)

    Kreter, K.; Goldstein, R.; Yakey, C.; Nemkov, V.

    2014-12-01

    In induction hardening, thermal fatigue is one of the main copper failure modes of induction heat treating coils. There have been papers published that describe this failure mode and others that describe some good design practices. The variables previously identified as the sources of thermal fatigue include radiation from the part surface, frequency, current, concentrator losses, water pressure and coil wall thickness. However, there is very little quantitative data on the factors that influence thermal fatigue in induction coils is available in the public domain. By using finite element analysis software this study analyzes the effect of common design variables of inductor cooling, and quantifies the relative importance of these variables. A comprehensive case study for a single shot induction coil with Fluxtrol A concentrator applied is used for the analysis.

  15. Doubly fed induction machine

    DOEpatents

    Skeist, S. Merrill; Baker, Richard H.

    2005-10-11

    An electro-mechanical energy conversion system coupled between an energy source and an energy load including an energy converter device having a doubly fed induction machine coupled between the energy source and the energy load to convert the energy from the energy source and to transfer the converted energy to the energy load and an energy transfer multiplexer coupled to the energy converter device to control the flow of power or energy through the doubly fed induction machine.

  16. Induction launcher design considerations

    NASA Technical Reports Server (NTRS)

    Driga, M. D.; Weldon, W. F.

    1989-01-01

    New concepts in the design of induction accelerators and their power supplies for space and military applications are discussed. Particular attention is given to a piecewise-rising-frequency power supply in which each elementary generator (normal compulsator or rising frequency generator) has a different base frequency. A preliminary design of a coaxial induction accelerator for a hypersonic real gas facility is discussed to illustrate the concepts described.

  17. Linear induction accelerator

    DOEpatents

    Buttram, M.T.; Ginn, J.W.

    1988-06-21

    A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities. 4 figs.

  18. Malformations of dorsal induction.

    PubMed

    Kanekar, Sangam; Kaneda, Heather; Shively, Alexis

    2011-06-01

    Dorsal induction includes the formation and closure of neural tube, occurs during 3-5 weeks of gestation. Neurulation occurs in two phases, primary neurulation (formation of the neural plate and subsequently neural tube) and secondary neurulation (formation of distal cord and sacral and coccygeal segments). Failure of dorsal induction leads to anencephaly, exencephaly, cephaloceles, Chiari malformation and spinal dysraphism. In this article we discuss the relevant embryology, etiopathology and detail imaging appearances of these malformations.

  19. Recombinant measles viruses expressing respiratory syncytial virus proteins induced virus-specific CTL responses in cotton rats.

    PubMed

    Yamaji, Yoshiaki; Nakayama, Tetsuo

    2014-07-31

    Respiratory syncytial virus (RSV) is a common cause of serious lower respiratory tract illnesses in infants. Natural infections with RSV provide limited protection against reinfection because of inefficient immunological responses that do not induce long-term memory. RSV natural infection has been shown to induce unbalanced immune response. The effective clearance of RSV is known to require the induction of a balanced Th1/Th2 immune response, which involves the induction of cytotoxic T lymphocytes (CTL). In our previous study, recombinant AIK-C measles vaccine strains MVAIK/RSV/F and MVAIK/RSV/G were developed, which expressed the RSV fusion (F) protein or glycoprotein (G). These recombinant viruses elicited antibody responses against RSV in cotton rats, and no infectious virus was recovered, but small amounts of infiltration of inflammatory cells were observed in the lungs following RSV challenge. In the present study, recombinant AIK-C measles vaccine strains MVAIK/RSV/M2-1 and MVAIK/RSV/NP were developed, expressing RSV M2-1 or Nucleoprotein (NP), respectively. These viruses exhibited temperature-sensitivity (ts), which was derived from AIK-C, and expressed respective RSV antigens. The intramuscular inoculation of cotton rats with the recombinant measles virus led to the induction of CD8(+) IFN-γ(+) cells. No infectious virus was recovered from a lung homogenate following the challenge. A Histological examination of the lungs revealed a significant reduction in inflammatory reactions without alveolar damage. These results support the recombinant measles viruses being effective vaccine candidates against RSV that induce RSV-specific CTL responses with or without the development of an antibody response.

  20. Induction in a Modular Learner.

    ERIC Educational Resources Information Center

    Carroll, Susanne E.

    2002-01-01

    Presents a theory of inductive learning--Autonomous Induction Theory--a form of induction that takes place within the autonomous and modular representational systems of the language faculty. Argues that Autonomous Induction Theory is constrained enough to be taken seriously as a plausible approach to explaining second language acquisition.…

  1. Mothers' experiences of induction

    PubMed Central

    Cartwright, Ann

    1977-01-01

    Mothers of a random sample of 2182 legitimate live births were interviewed about their experiences of pregnancy, labour, and delivery. Of these, 24% reported that their labours were induced, and data about this from a subsample of mothers tallied with information obtained through the doctors in charge in 88% of cases. All but 3% of the mothers who were induced perceived some medical reason for the induction. The proportion of inductions in the 24 study areas ranged from 6% to 39%. A relatively small proportion of labours in “teaching” hospitals, small hospitals with less than 100 beds, and GP maternity hospitals were induced, but a comparatively high proportion of private patients had an induction. There was no clear association between induction and the mother's age or parity. Despite being given more pain relief, those who were induced reported similar intensities of pain during the first and second stages of labour to those whose labour started spontaneously; they also reported that they had “bad pains” for a similar period. The period they had contractions was shorter for the induced than for those starting spontaneously, and the intensity of pain at delivery was rated somewhat less by those who were induced. There was no difference between induced babies and others in the proportion who were held by their mothers immediately after their birth. Two-fifths of the mothers who were induced would have liked more information about induction; and a similar proportion said they had not discussed induction with a doctor, midwife, or nurse during their pregnancy. Only 17% of the mothers who had an induction said they would prefer to be induced if they had another baby. This contrasts with 63% of those who had epidural analgesia who would opt for the same procedure next time, while 83% of those who had had a baby in hospital, and 91% of those having had a home birth, would want their next baby in the same type of place. PMID:912282

  2. Remodeling sensory cortical maps implants specific behavioral memory.

    PubMed

    Bieszczad, K M; Miasnikov, A A; Weinberger, N M

    2013-08-29

    Neural mechanisms underlying the capacity of memory to be rich in sensory detail are largely unknown. A candidate mechanism is learning-induced plasticity that remodels the adult sensory cortex. Here, expansion in the primary auditory cortical (A1) tonotopic map of rats was induced by pairing a 3.66-kHz tone with activation of the nucleus basalis, mimicking the effects of natural associative learning. Remodeling of A1 produced de novo specific behavioral memory, but neither memory nor plasticity was consistently at the frequency of the paired tone, which typically decreased in A1 representation. Rather, there was a specific match between individual subjects' area of expansion and the tone that was strongest in each animal's memory, as determined by post-training frequency generalization gradients. These findings provide the first demonstration of a match between the artificial induction of specific neural representational plasticity and artificial induction of behavioral memory. As such, together with prior and present findings for detection, correlation and mimicry of plasticity with the acquisition of memory, they satisfy a key criterion for neural substrates of memory. This demonstrates that directly remodeling sensory cortical maps is sufficient for the specificity of memory formation.

  3. Situated navigational working memory: the role of positive mood.

    PubMed

    Palmiero, Massimiliano; Nori, Raffaella; Rogolino, Carmelo; D'Amico, Simonetta; Piccardi, Laura

    2015-09-01

    The perspective of situated cognition assumes that cognition is not separated from the context. In the present study, the issue if visuospatial memory and navigational working memory are situated was explored by manipulating participants' mood (positive, negative and neutral) while performing two different tasks. College students were randomly assigned to the group of positive, negative or neutral music. Participants filled out the positive and negative affect schedule (PANAS) before and after carrying out the Corsi Test and the Walking Corsi Test. Both tasks were performed forward and backward. Music was played throughout the memory tasks. Firstly, comparing pre-mood induction PANAS scores to post-mood induction PANAS scores, results showed that only positive affects were manipulated: After mood induction, the Positive Music Group produced higher scores, whereas the Negative Music Group produced lower scores than before mood induction; the Neutral Music Group produced no effect. Secondly, the Positive Music Group produced higher scores than Negative and Neutral Music Groups both at the Corsi Test and at the Walking Corsi Test. These results show that situational contexts that induce a specific mood can affect visuospatial memory and navigational working memory, and open to the idea that positive emotions may play a crucial role in enhancing navigational strategies.

  4. Memory Retrieval and Interference: Working Memory Issues

    ERIC Educational Resources Information Center

    Radvansky, Gabriel A.; Copeland, David E.

    2006-01-01

    Working memory capacity has been suggested as a factor that is involved in long-term memory retrieval, particularly when that retrieval involves a need to overcome some sort of interference (Bunting, Conway, & Heitz, 2004; Cantor & Engle, 1993). Previous work has suggested that working memory is related to the acquisition of information during…

  5. Episodic memory, semantic memory, and amnesia.

    PubMed

    Squire, L R; Zola, S M

    1998-01-01

    Episodic memory and semantic memory are two types of declarative memory. There have been two principal views about how this distinction might be reflected in the organization of memory functions in the brain. One view, that episodic memory and semantic memory are both dependent on the integrity of medial temporal lobe and midline diencephalic structures, predicts that amnesic patients with medial temporal lobe/diencephalic damage should be proportionately impaired in both episodic and semantic memory. An alternative view is that the capacity for semantic memory is spared, or partially spared, in amnesia relative to episodic memory ability. This article reviews two kinds of relevant data: 1) case studies where amnesia has occurred early in childhood, before much of an individual's semantic knowledge has been acquired, and 2) experimental studies with amnesic patients of fact and event learning, remembering and knowing, and remote memory. The data provide no compelling support for the view that episodic and semantic memory are affected differently in medial temporal lobe/diencephalic amnesia. However, episodic and semantic memory may be dissociable in those amnesic patients who additionally have severe frontal lobe damage.

  6. Wrapper Induction Software

    2011-08-18

    Wrapper Induction is a software package that allows for unsupervised, semi-supervised, and manual extraction of social media data independent of language or site architecture. A large range of blog formats is available to individuals as means of publishing data to the internet. Blogs are a source of rich information for analysts. With a growing volume of information and blog engines, there is an increased need for automatic or semi-automatic extraction of that data for processingmore » to help deliver results to analysts. Wrapper Induction is designed to automatically or semi-automatically create a template that can be used to harvest blog data from websites. Blogs are in a variety of formats and languages. Wrapper Induction creates a template and extracts blog data in a way that is independent of a specified blog format or language.« less

  7. Wrapper Induction Software

    SciTech Connect

    2011-08-18

    Wrapper Induction is a software package that allows for unsupervised, semi-supervised, and manual extraction of social media data independent of language or site architecture. A large range of blog formats is available to individuals as means of publishing data to the internet. Blogs are a source of rich information for analysts. With a growing volume of information and blog engines, there is an increased need for automatic or semi-automatic extraction of that data for processing to help deliver results to analysts. Wrapper Induction is designed to automatically or semi-automatically create a template that can be used to harvest blog data from websites. Blogs are in a variety of formats and languages. Wrapper Induction creates a template and extracts blog data in a way that is independent of a specified blog format or language.

  8. Optical memory

    DOEpatents

    Mao, Samuel S; Zhang, Yanfeng

    2013-07-02

    Optical memory comprising: a semiconductor wire, a first electrode, a second electrode, a light source, a means for producing a first voltage at the first electrode, a means for producing a second voltage at the second electrode, and a means for determining the presence of an electrical voltage across the first electrode and the second electrode exceeding a predefined voltage. The first voltage, preferably less than 0 volts, different from said second voltage. The semiconductor wire is optically transparent and has a bandgap less than the energy produced by the light source. The light source is optically connected to the semiconductor wire. The first electrode and the second electrode are electrically insulated from each other and said semiconductor wire.

  9. An episodic specificity induction enhances means-end problem solving in young and older adults.

    PubMed

    Madore, Kevin P; Schacter, Daniel L

    2014-12-01

    Episodic memory plays an important role not only in remembering past experiences, but also in constructing simulations of future experiences and solving means-end social problems. We recently found that an episodic specificity induction-brief training in recollecting details of past experiences-enhances performance of young and older adults on memory and imagination tasks. Here we tested the hypothesis that this specificity induction would also positively impact a means-end problem-solving task on which age-related changes have been linked to impaired episodic memory. Young and older adults received the specificity induction or a control induction before completing a means-end problem-solving task, as well as memory and imagination tasks. Consistent with previous findings, older adults provided fewer relevant steps on problem solving than did young adults, and their responses also contained fewer internal (i.e., episodic) details across the 3 tasks. There was no difference in the number of other (e.g., irrelevant) steps on problem solving or external (i.e., semantic) details generated on the 3 tasks as a function of age. Critically, the specificity induction increased the number of relevant steps and internal details (but not other steps or external details) that both young and older adults generated in problem solving compared with the control induction, as well as the number of internal details (but not external details) generated for memory and imagination. Our findings support the idea that episodic retrieval processes are involved in means-end problem solving, extend the range of tasks on which a specificity induction targets these processes, and show that the problem-solving performance of older adults can benefit from a specificity induction as much as that of young adults.

  10. An episodic specificity induction enhances means-end problem solving in young and older adults

    PubMed Central

    Madore, Kevin P.; Schacter, Daniel L.

    2014-01-01

    Episodic memory plays an important role not only in remembering past experiences, but also in constructing simulations of future experiences and solving means-end social problems. We recently found that an episodic specificity induction- brief training in recollecting details of past experiences- enhances performance of young and older adults on memory and imagination tasks. Here we tested the hypothesis that this specificity induction would also positively impact a means-end problem solving task on which age-related changes have been linked to impaired episodic memory. Young and older adults received the specificity induction or a control induction before completing a means-end problem solving task as well as memory and imagination tasks. Consistent with previous findings, older adults provided fewer relevant steps on problem solving than did young adults, and their responses also contained fewer internal (i.e., episodic) details across the three tasks. There was no difference in the number of other (e.g., irrelevant) steps on problem solving or external (i.e., semantic) details generated on the three tasks as a function of age. Critically, the specificity induction increased the number of relevant steps and internal details (but not other steps or external details) that both young and older adults generated in problem solving compared with the control induction, as well as the number of internal details (but not external details) generated for memory and imagination. Our findings support the idea that episodic retrieval processes are involved in means-end problem solving, extend the range of tasks on which a specificity induction targets these processes, and show that the problem solving performance of older adults can benefit from a specificity induction as much as that of young adults. PMID:25365688

  11. Specific lysis of human immunodeficiency virus type 1-infected cells by a HLA-A3.1-restricted CD8+ cytotoxic T-lymphocyte clone that recognizes a conserved peptide sequence within the gp41 subunit of the envelope protein.

    PubMed Central

    Takahashi, K; Dai, L C; Fuerst, T R; Biddison, W E; Earl, P L; Moss, B; Ennis, F A

    1991-01-01

    A HLA-A3.1-restricted CD8+ cytotoxic T-cell clone, E7.20, that lyses cells infected with human immunodeficiency virus type 1 was isolated from an infected individual. The epitope was localized to amino acids 768-778 (RLRDLLLIVTR, NL43 env sequence) of the cytoplasmic domain of gp41 by successive use of a panel of recombinant vaccinia viruses that express truncated env genes and synthetic peptides. The epitope is conserved on 7 (NL43, BRU, HXB2, BRVA, SC, JH3, and JFL) of 13 human immunodeficiency virus type 1 isolates from North America. Synthetic peptides of this region of strains RF and CDC4 are also recognized by E7.20 despite a nonconservative Thr----Val or Thr----Ala change at amino acid 777; however, an MN peptide, which has four amino acid substitutions, was not reactive. The epitope recognized by E7.20 has a predicted hydrophobic alpha-helical structure, with three contiguous Leu residues followed by Ile and Val at amino acids 772-776. Cytotoxicity was restricted by HLA-A3.1 using allogeneic target cells that shared HLA class I antigens with the donor and an HLA-A and -B negative human plasma cell line transfected with the HLA-A3.1 gene. The transfected cells were infectable by human immunodeficiency virus type 1 strains IIIB and MN but only the former virus sensitized them to killing by E7.20. The ability of E7.20 to specifically lyse a human lymphocyte line infected with a human immunodeficiency virus type 1 strain carrying the conserved epitope is consistent with an important role for cytotoxic T cells in controlling infection. PMID:1719555

  12. Using Implicit Instructional Cues to Influence False Memory Induction

    ERIC Educational Resources Information Center

    Cirelli, Laura K.; Dickinson, Joël; Poirier, Marie

    2015-01-01

    Previous research has shown that explicit cues specific to the encoding process (endogenous) or characteristic of the stimuli themselves (exogenous) can be used to direct a reader's attentional resources towards either relational or item-specific information. By directing attention to relational information (and therefore away from item-specific…

  13. HIGH GRADIENT INDUCTION ACCELERATOR

    SciTech Connect

    Caporaso, G J; Sampayan, S; Chen, Y; Blackfield, D; Harris, J; Hawkins, S; Holmes, C; Krogh, M; Nelson, S; Nunnally, W; Paul, A; Poole, B; Rhodes, M; Sanders, D; Selenes, K; Sullivan, J; Wang, L; Watson, J

    2007-06-21

    A new type of compact induction accelerator is under development at the Lawrence Livermore National Laboratory that promises to increase the average accelerating gradient by at least an order of magnitude over that of existing induction machines. The machine is based on the use of high gradient vacuum insulators, advanced dielectric materials and switches and is stimulated by the desire for compact flash x-ray radiography sources. Research describing an extreme variant of this technology aimed at proton therapy for cancer will be described. Progress in applying this technology to several applications will be reviewed.

  14. Induction powered biological radiosonde

    NASA Technical Reports Server (NTRS)

    Fryer, T. B. (Inventor)

    1980-01-01

    An induction powered implanted monitor for epidurally measuring intracranial pressure and telemetering the pressure information to a remote readout is disclosed. The monitor utilizes an inductance-capacitance (L-C) oscillator in which the C comprises a variable capacitance transducer, one electrode of which is a small stiff pressure responsive diaphragm. The oscillator is isolated from a transmitting tank circuit by a buffer circuit and all electric components in the implanted unit except an input and an output coil are shielded by a metal housing.

  15. Inductive Adder development

    SciTech Connect

    Miller, R.B.; Davis, B.B.; Bayless, J.

    1989-05-01

    TITAN has successfully developed an Inductive Adder for use with a Hewlett-Packard Model 43734A Marx pulser. The unit provides an 800 kV peak output pulse to a modified HP 5081-9551 1 MV x-ray tube. The tube fits into the adder unit, and can thus be remotely operated. It delivers a peak on-axis dose of 35 mR at a one meter distance. Supporting radiography analyses, a description of the inductive adder approach and construction, and detailed test data are presented.

  16. Shape-Memory Polymer Composites

    NASA Astrophysics Data System (ADS)

    Madbouly, Samy A.; Lendlein, Andreas

    The development of shape-memory polymer composites (SMPCs) enables high recovery stress levels as well as novel functions such as electrical conductivity, magnetism, and biofunctionality. In this review chapter the substantial enhancement in mechanical properties of shape-memory polymers (SMPs) by incorporating small amounts of stiff fillers will be highlighted exemplarily for clay and polyhedral oligomeric silsesquioxanes (POSS). Three different functions resulting from adding functional fillers to SMP-matrices will be introduced and discussed: magnetic SMPCs with different types of magnetic nanoparticles, conductive SMPCs based on carbon nanotubes (CNTs), carbon black (CB), short carbon fiber (SCF), and biofunctional SMPCs containing hydroxyapatite (HA). Indirect induction of the shape-memory effect (SME) was realized for magnetic and conductive SMPCs either by exposure to an alternating magnetic field or by application of electrical current. Major challenges in design and fundamental understanding of polymer composites are the complexity of the composite structure, and the relationship between structural parameters and properties/functions, which is essential for tailoring SMPCs for specific applications. Therefore the novel functions and enhanced properties of SMPCs will be described considering the micro-/nanostructural parameters, such as dimension, shape, distribution, volume fraction, and alignment of fillers as well as interfacial interaction between the polymer matrix and dispersed fillers. Finally, an outlook is given describing the future challenges of this exciting research field as well as potential applications including automotive, aerospace, sensors, and biomedical applications.

  17. Sleep, Torpor and Memory Impairment

    NASA Astrophysics Data System (ADS)

    Palchykova, S.; Tobler, I.

    It is now well known that daily torpor induces a sleep deficit. Djungarian hamsters emerging from this hypometabolic state spend most of the time in sleep. This sleep is characterized by high initial values of EEG slow-wave activity (SWA) that monotonically decline during recovery sleep. These features resemble the changes seen in numerous species during recovery after prolonged wakefulness or sleep deprivation (SD). When hamsters are totally or partially sleep deprived immediately after emerging from torpor, an additional increase in SWA can be induced. It has been therefore postulated, that these slow- waves are homeostatically regulated, as predicted by the two-process model of sleep regulation, and that during daily torpor a sleep deficit is accumulated as it is during prolonged waking. The predominance of SWA in the frontal EEG observed both after SD and daily torpor provides further evidence for the similarity of these conditions. It has been shown in several animal and human studies that sleep can enhance memory consolidation, and that SD leads to memory impairment. Preliminary data obtained in the Djungarian hamster showed that both SD and daily torpor result in object recognition deficits. Thus, animals subjected to SD immediately after learning, or if they underwent an episode of daily torpor between learning and retention, displayed impaired recognition memory for complex object scenes. The investigation of daily torpor can reveal mechanisms that could have important implications for hypometabolic state induction in other mammalian species, including humans.

  18. In vivo administration of interleukin-2 protects susceptible mice from Theiler's virus persistence.

    PubMed Central

    Larsson-Sciard, E L; Dethlefs, S; Brahic, M

    1997-01-01

    In vivo administration of interleukin-2 (IL-2)-secreting tumor cells results in complete protection against persistent infection by Theiler's murine encephalomyelitis virus (TMEV) in susceptible DBA/2 mice. The IL-2-mediated protection was found to depend on the inoculum size as well as the timing of IL-2 administration. IL-2-treated and TMEV-infected mice displayed a three- to fourfold relative increase in virus-specific cytotoxic T-lymphocyte (CTL) precursors. Thus, we postulate that the persistence of TMEV infection in susceptible mice reflects limited numbers of relevant CTL precursors and their time course of induction and activation. PMID:8985419

  19. Infant Visual Recognition Memory

    ERIC Educational Resources Information Center

    Rose, Susan A.; Feldman, Judith F.; Jankowski, Jeffery J.

    2004-01-01

    Visual recognition memory is a robust form of memory that is evident from early infancy, shows pronounced developmental change, and is influenced by many of the same factors that affect adult memory; it is surprisingly resistant to decay and interference. Infant visual recognition memory shows (a) modest reliability, (b) good discriminant…

  20. Memory and the brain.

    PubMed

    Robertson, Lee T

    2002-01-01

    This review summarizes some of the recent advances in the neurobiology of memory. Current research helps us to understand how memories are created and, conversely, how our memories can be influenced by stress, drugs, and aging. An understanding of how memories are encoded by the brain may also lead to new ideas about how to maximize the long-term retention of important information. There are multiple memory systems with different functions and, in this review, we focus on the conscious recollection of one's experience of events and facts and on memories tied to emotional responses. Memories are also classified according to time: from short-term memory, lasting only seconds or minutes, to long-term memory, lasting months or years. The advent of new functional neuroimaging methods provides an opportunity to gain insight into how the human brain supports memory formation. Each memory system has a distinct anatomical organization, where different parts of the brain are recruited during phases of memory storage. Within the brain, memory is a dynamic property of populations of neurons and their interconnections. Memories are laid down in our brains via chemical changes at the neuron level. An understanding of the neurobiology of memory may stimulate health educators to consider how various teaching methods conform to the process of memory formation. PMID:12358099

  1. Using Continuity Induction

    ERIC Educational Resources Information Center

    Hathaway, Dan

    2011-01-01

    Here is a technique for proving the fundamental theorems of analysis that provides a unified way to pass from local properties to global properties on the real line, just as ordinary induction passes from local implication (if true for "k", the theorem is true for "k" + 1) to a global conclusion in the natural numbers.

  2. Induction and Well Ordering

    ERIC Educational Resources Information Center

    Pinker, Aron

    1976-01-01

    In a pilot study of college students' understanding of mathematical induction, the author asked 2,320 students and 152 faculty members to determine whether eight statements were true or false. The difficulty of the statements was analyzed for subgroups of the population. (SD)

  3. Induction technology optimization code

    SciTech Connect

    Caporaso, G.J.; Brooks, A.L.; Kirbie, H.C.

    1992-08-21

    A code has been developed to evaluate relative costs of induction accelerator driver systems for relativistic klystrons. The code incorporates beam generation, transport and pulsed power system constraints to provide an integrated design tool. The code generates an injector/accelerator combination which satisfies the top level requirements and all system constraints once a small number of design choices have been specified (rise time of the injector voltage and aspect ratio of the ferrite induction cores, for example). The code calculates dimensions of accelerator mechanical assemblies and values of all electrical components. Cost factors for machined parts, raw materials and components are applied to yield a total system cost. These costs are then plotted as a function of the two design choices to enable selection of an optimum design based on various criteria. The Induction Technology Optimization Study (ITOS) was undertaken to examine viable combinations of a linear induction accelerator and a relativistic klystron (RK) for high power microwave production. It is proposed, that microwaves from the RK will power a high-gradient accelerator structure for linear collider development. Previous work indicates that the RK will require a nominal 3-MeV, 3-kA electron beam with a 100-ns flat top. The proposed accelerator-RK combination will be a high average power system capable of sustained microwave output at a 300-Hz pulse repetition frequency. The ITOS code models many combinations of injector, accelerator, and pulse power designs that will supply an RK with the beam parameters described above.

  4. Electron Induction Linacs

    NASA Astrophysics Data System (ADS)

    Caporaso, George J.; Chen, Yu-Jiuan

    Electron induction linacs have been used for over four decades for a variety of applications. As discussed in Chap. 8, these include basic studies in magnetically confined fusion, transport of intense electron beams in various gases, the generation of electromagnetic radiation from free electron lasers, radiation processing of materials and food, and flash X-ray radiography sources.

  5. Educational Inductive Gravimeter

    ERIC Educational Resources Information Center

    Nunn, John

    2014-01-01

    A simple inductive gravimeter constructed from a rigid plastic pipe and insulated copper wire is described. When a magnet is dropped through the vertically mounted pipe it induces small alternating voltages. These small signals are fed to the microphone input of a typical computer and sampled at a typical rate of 44.1 kHz using a custom computer…

  6. Iteration, Not Induction

    ERIC Educational Resources Information Center

    Dobbs, David E.

    2009-01-01

    The main purpose of this note is to present and justify proof via iteration as an intuitive, creative and empowering method that is often available and preferable as an alternative to proofs via either mathematical induction or the well-ordering principle. The method of iteration depends only on the fact that any strictly decreasing sequence of…

  7. Chimeric SV40 virus-like particles induce specific cytotoxicity and protective immunity against influenza A virus without the need of adjuvants

    SciTech Connect

    Kawano, Masaaki; Morikawa, Katsuma; Suda, Tatsuya; Ohno, Naohito; Matsushita, Sho; Akatsuka, Toshitaka; Handa, Hiroshi; Matsui, Masanori

    2014-01-05

    Virus-like particles (VLPs) are a promising vaccine platform due to the safety and efficiency. However, it is still unclear whether polyomavirus-based VLPs are useful for this purpose. Here, we attempted to evaluate the potential of polyomavirus VLPs for the antiviral vaccine using simian virus 40 (SV40). We constructed chimeric SV40-VLPs carrying an HLA-A{sup ⁎}02:01-restricted, cytotoxic T lymphocyte (CTL) epitope derived from influenza A virus. HLA-A{sup ⁎}02:01-transgenic mice were then immunized with the chimeric SV40-VLPs. The chimeric SV40-VLPs effectively induced influenza-specific CTLs and heterosubtypic protection against influenza A viruses without the need of adjuvants. Because DNase I treatment of the chimeric SV40-VLPs did not disrupt CTL induction, the intrinsic adjuvant property may not result from DNA contaminants in the VLP preparation. In addition, immunization with the chimeric SV40-VLPs generated long-lasting memory CTLs. We here propose that the chimeric SV40-VLPs harboring an epitope may be a promising CTL-based vaccine platform with self-adjuvant properties. - Highlights: • We constructed chimeric SV40-VLPs carrying an influenza virus-derived CTL epitope. • Chimeric SV40-VLPs induce influenza-specific CTLs in mice without adjuvants. • Chimeric SV40-VLPs induce heterosubtypic protection against influenza A viruses. • Chimeric SV40-VLPs induce long-lasting memory CTLs. • Chimeric SV40-VLPs is a promising vaccine platform with self-adjuvant properties.

  8. High current induction linacs

    NASA Astrophysics Data System (ADS)

    Barletta, W.; Faltens, A.; Henestroza, E.; Lee, E.

    1994-07-01

    Induction linacs are among the most powerful accelerators in existence. They have accelerated electron bunches of several kiloamperes, and are being investigated as drivers for heavy ion driven inertial confinement fusion (HIF), which requires peak beam currents of kiloamperes and average beam powers of some tens of megawatts. The requirement for waste transmutation with an 800 MeV proton or deuteron beam with an average current of 50 mA and an average power of 40 MW lies midway between the electron machines and the heavy ion machines in overall difficulty. Much of the technology and understanding of beam physics carries over from the previous machines to the new requirements. The induction linac allows use of a very large beam aperture, which may turn out to be crucial to reducing beam loss and machine activation from the beam halo. The major issues addressed here are transport of high intensity beams, availability of sources, efficiency of acceleration, and the state of the needed technology for the waste treatment application. Because of the transformer-like action of an induction core and the accompanying magnetizing current, induction linacs make the most economic sense and have the highest efficiencies with large beam currents. Based on present understanding of beam transport limits, induction core magnetizing current requirements, and pulse modulators, the efficiencies could be very high. The study of beam transport at high intensities has been the major activity of the HIF community. Beam transport and sources are limiting at low energies but are not significant constraints at the higher energies. As will be shown, the proton beams will be space-charge-dominated, for which the emittance has only a minor effect on the overall beam diameter but does determine the density falloff at the beam edge.

  9. Verbal memory and menopause.

    PubMed

    Maki, Pauline M

    2015-11-01

    Midlife women frequently report memory problems during the menopausal transition. Recent studies validate those complaints by showing significant correlations between memory complaints and performance on validated memory tasks. Longitudinal studies demonstrate modest declines in verbal memory during the menopausal transition and a likely rebound during the postmenopausal stage. Clinical studies that examine changes in memory following hormonal withdrawal and add-back hormone therapy (HT) demonstrate that estradiol plays a critical role in memory. Although memory changes are frequently attributed to menopausal symptoms, studies show that the memory problems occur during the transition even after controlling for menopausal symptoms. It is well established that self-reported vasomotor symptoms (VMS) are unrelated to objective memory performance. However, emerging evidence suggests that objectively measured VMS significantly correlate with memory performance, brain activity during rest, and white matter hyperintensities. This evidence raises important questions about whether VMS and VMS treatments might affect memory during the menopausal transition. Unfortunately, there are no clinical trials to inform our understanding of how HT affects both memory and objectively measured VMS in women in whom HT is indicated for treatment of moderate to severe VMS. In clinical practice, it is helpful to normalize memory complaints, to note that evidence suggests that memory problems are temporary, and to counsel women with significant VMS that memory might improve with treatment.

  10. Staff Induction: Issues Surrounding Induction into International Schools

    ERIC Educational Resources Information Center

    Stirzaker, Rosalind

    2004-01-01

    This article analyses the literature on staff induction into international schools. It defines what is meant by the term "induction" and identifies the benefits to both individuals and organization if it is done well. It stresses that induction is a process, not an event, and discusses the various stages involved: the initial recruitment, the…

  11. Memory Metals

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Under contract to NASA during preparations for the space station, Memry Technologies Inc. investigated shape memory effect (SME). SME is a characteristic of certain metal alloys that can change shape in response to temperature variations. In the late 1980s and early 1990s, Memry used its NASA-acquired expertise to produce a line of home and industrial safety products, and refined the technology in the mid-1990s. Among the new products they developed are three MemrySafe units which prevent scalding from faucets. Each system contains a small valve that reacts to temperature, not pressure. When the water reaches dangerous temperatures, the unit reduces the flow to a trickle; when the scalding temperature subsides, the unit restores normal flow. Other products are the FIRECHEK 2 and 4, heat-activated shutoff valves for industrial process lines, which sense excessive heat and cut off pneumatic pressure. The newest of these products is Memry's Demand Management Water Heater which shifts the electricity requirement from peak to off-peak demands, conserving energy and money.

  12. Drink, drugs and disruption: memory manipulation for the treatment of addiction.

    PubMed

    Milton, A L

    2013-08-01

    Addiction is a complex disorder, and one characterised by the acquisition of maladaptive instrumental (drug-seeking and drug-taking) and pavlovian (cue-drug associations) memories. These memories markedly contribute to the long-term risk of relapse, so reduction of the impact of these memories on behaviour could potentially be an important addition to current therapies for addiction. Memory reconsolidation may provide such a target for disrupting well-consolidated pavlovian cue-drug memories following an extensive drug history. Reconsolidation can be disrupted either by administering amnestic drugs in conjunction with a memory reactivation session, or by updating the memory adaptively through the induction of 'superextinction'. More work is needed before these therapies are ready for translation to the clinic, but if found clinically effective memory manipulation promises a radical new way of treating addiction.

  13. Drink, drugs and disruption: memory manipulation for the treatment of addiction.

    PubMed

    Milton, A L

    2013-08-01

    Addiction is a complex disorder, and one characterised by the acquisition of maladaptive instrumental (drug-seeking and drug-taking) and pavlovian (cue-drug associations) memories. These memories markedly contribute to the long-term risk of relapse, so reduction of the impact of these memories on behaviour could potentially be an important addition to current therapies for addiction. Memory reconsolidation may provide such a target for disrupting well-consolidated pavlovian cue-drug memories following an extensive drug history. Reconsolidation can be disrupted either by administering amnestic drugs in conjunction with a memory reactivation session, or by updating the memory adaptively through the induction of 'superextinction'. More work is needed before these therapies are ready for translation to the clinic, but if found clinically effective memory manipulation promises a radical new way of treating addiction. PMID:23265965

  14. Measurement of Self-Inductance.

    ERIC Educational Resources Information Center

    Mak, S. Y.; Tao, P. K.

    1988-01-01

    Discusses four different methods for measuring self-inductance based on the definition of inductance, the alternative definition, phase difference and LC resonance. Provides circuit diagrams and typical oscilloscope traces. (YP)

  15. Immune Profile of Pediatric Renal Transplant Recipients following Alemtuzumab Induction

    PubMed Central

    De Serres, Sacha A.; Mfarrej, Bechara G.; Magee, Ciara N.; Benitez, Fanny; Ashoor, Isa; Sayegh, Mohamed H.; Harmon, William E.

    2012-01-01

    The incidence of developing circulating anti-human leukocyte antigen antibodies and the kinetics of T cell depletion and recovery among pediatric renal transplant recipients who receive alemtuzumab induction therapy are unknown. In a collaborative endeavor to minimize maintenance immunosuppression in pediatric renal transplant recipients, we enrolled 35 participants from four centers and treated them with alemtuzumab induction therapy and a steroid-free, calcineurin-inhibitor–withdrawal maintenance regimen. At 3 months after transplant, there was greater depletion of CD4+ than CD8+ T cells within the total, naive, memory, and effector memory subsets, although depletion of the central memory subset was similar for CD4+ and CD8+ cells. Although CD8+ T cells recovered faster than CD4+ subsets overall, they failed to return to pretransplant levels by 24 months after transplant. There was no evidence for greater recovery of either CD4+ or CD8+ memory cells than naïve cells. Alemtuzumab relatively spared CD4+CD25+FoxP3+ regulatory T cells, resulting in a rise in their numbers relative to total CD4+ cells and a ratio that remained at least at pretransplant levels throughout the study period. Seven participants (20%) developed anti-human leukocyte antigen antibodies without adversely affecting allograft function or histology on 2-year biopsies. Long-term follow-up is underway to assess the potential benefits of this regimen in children. PMID:22052056

  16. Inductive Reasoning: A Training Approach

    ERIC Educational Resources Information Center

    Klauer, Karl Josef; Phye, Gary D.

    2008-01-01

    Researchers have examined inductive reasoning to identify different cognitive processes when participants deal with inductive problems. This article presents a prescriptive theory of inductive reasoning that identifies cognitive processing using a procedural strategy for making comparisons. It is hypothesized that training in the use of the…

  17. Latent memory facilitates relearning through molecular signaling mechanisms that are distinct from original learning.

    PubMed

    Menges, Steven A; Riepe, Joshua R; Philips, Gary T

    2015-09-01

    A highly conserved feature of memory is that it can exist in a latent, non-expressed state which is revealed during subsequent learning by its ability to significantly facilitate (savings) or inhibit (latent inhibition) subsequent memory formation. Despite the ubiquitous nature of latent memory, the mechanistic nature of the latent memory trace and its ability to influence subsequent learning remains unclear. The model organism Aplysia californica provides the unique opportunity to make strong links between behavior and underlying cellular and molecular mechanisms. Using Aplysia, we have studied the mechanisms of savings due to latent memory for a prior, forgotten experience. We previously reported savings in the induction of three distinct temporal domains of memory: short-term (10min), intermediate-term (2h) and long-term (24h). Here we report that savings memory formation utilizes molecular signaling pathways that are distinct from original learning: whereas the induction of both original intermediate- and long-term memory in naïve animals requires mitogen activated protein kinase (MAPK) activation and ongoing protein synthesis, 2h savings memory is not disrupted by inhibitors of MAPK or protein synthesis, and 24h savings memory is not dependent on MAPK activation. Collectively, these findings reveal that during forgetting, latent memory for the original experience can facilitate relearning through molecular signaling mechanisms that are distinct from original learning. PMID:25957134

  18. Latent memory facilitates relearning through molecular signaling mechanisms that are distinct from original learning.

    PubMed

    Menges, Steven A; Riepe, Joshua R; Philips, Gary T

    2015-09-01

    A highly conserved feature of memory is that it can exist in a latent, non-expressed state which is revealed during subsequent learning by its ability to significantly facilitate (savings) or inhibit (latent inhibition) subsequent memory formation. Despite the ubiquitous nature of latent memory, the mechanistic nature of the latent memory trace and its ability to influence subsequent learning remains unclear. The model organism Aplysia californica provides the unique opportunity to make strong links between behavior and underlying cellular and molecular mechanisms. Using Aplysia, we have studied the mechanisms of savings due to latent memory for a prior, forgotten experience. We previously reported savings in the induction of three distinct temporal domains of memory: short-term (10min), intermediate-term (2h) and long-term (24h). Here we report that savings memory formation utilizes molecular signaling pathways that are distinct from original learning: whereas the induction of both original intermediate- and long-term memory in naïve animals requires mitogen activated protein kinase (MAPK) activation and ongoing protein synthesis, 2h savings memory is not disrupted by inhibitors of MAPK or protein synthesis, and 24h savings memory is not dependent on MAPK activation. Collectively, these findings reveal that during forgetting, latent memory for the original experience can facilitate relearning through molecular signaling mechanisms that are distinct from original learning.

  19. Agrobacterium virulence gene induction.

    PubMed

    Gelvin, Stanton B

    2006-01-01

    The ability of Agrobacterium to transform plants and other organisms is under highly regulated genetic control. Two Virulence (Vir) proteins, VirA and VirG, function as a two-component regulatory system to sense particular phenolic compounds synthesized by wounded plant tissues. Induction by these phenolic compounds, in the presence of certain neutral or acid sugars, results in activation of other vir genes, leading to the processing of T-DNA from the Ti-plasmid and transfer of T-DNA to recipient host cells. Many plant, and most nonplant, species do not provide sufficient quantities of the correct phenolic compounds to permit efficient Agrobacterium-mediated genetic transformation to occur. In order to transform these species, phenolic inducing compounds must be added to agrobacteria before and/or during cocultivation of recipient cells with the bacteria. This chapter discusses conditions for efficient induction of Agrobacterium virulence genes by phenolic compounds. PMID:16988335

  20. Inductive Position Sensor

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert C. (Inventor); Simmons, Stephen M. (Inventor)

    2015-01-01

    An inductive position sensor uses three independent inductors inductively coupled by a common medium such as air. First and second inductors are separated by a fixed distance with the first inductor's axial core and second inductor's axial core maintained parallel to one another. A third inductor is disposed between the first and second inductors with the third inductor's axial core being maintained parallel to those of the first and second inductors. The combination of the first and second inductors are configured for relative movement with the third inductor's axial core remaining parallel to those of the first and second inductors as distance changes from the third inductor to each of the first inductor and second inductor. An oscillating current can be supplied to at least one of the three inductors, while voltage induced in at least one of the three inductors not supplied with the oscillating current is measured.

  1. Induction plasma tube

    DOEpatents

    Hull, D.E.

    1982-07-02

    An induction plasma tube having a segmented, fluid-cooled internal radiation shield is disclosed. The individual segments are thick in cross-section such that the shield occupies a substantial fraction of the internal volume of the plasma enclosure, resulting in improved performance and higher sustainable plasma temperatures. The individual segments of the shield are preferably cooled by means of a counterflow fluid cooling system wherein each segment includes a central bore and a fluid supply tube extending into the bore. The counterflow cooling system results in improved cooling of the individual segments and also permits use of relatively larger shield segments which permit improved electromagnetic coupling between the induction coil and a plasma located inside the shield. Four embodiments of the invention, each having particular advantages, are disclosed.

  2. Induction plasma tube

    DOEpatents

    Hull, Donald E.

    1984-01-01

    An induction plasma tube having a segmented, fluid-cooled internal radiation shield is disclosed. The individual segments are thick in cross-section such that the shield occupies a substantial fraction of the internal volume of the plasma enclosure, resulting in improved performance and higher sustainable plasma temperatures. The individual segments of the shield are preferably cooled by means of a counterflow fluid cooling system wherein each segment includes a central bore and a fluid supply tube extending into the bore. The counterflow cooling system results in improved cooling of the individual segments and also permits use of relatively larger shield segments which permit improved electromagnetic coupling between the induction coil and a plasma located inside the shield. Four embodiments of the invention, each having particular advantages, are disclosed.

  3. Induction motor control

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.

    1990-01-01

    Electromechanical actuators developed to date have commonly utilized permanent magnet (PM) synchronous motors. More recently switched reluctance (SR) motors have been advocated due to their robust characteristics. Implications of work which utilizes induction motors and advanced control techniques are discussed. When induction motors are operated from an energy source capable of controlling voltages and frequencies independently, drive characteristics are obtained which are superior to either PM or SR motors. By synthesizing the machine frequency from a high frequency carrier (nominally 20 kHz), high efficiencies, low distortion, and rapid torque response are available. At this time multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of aerospace actuators. This effort is based upon high frequency power distribution and management techniques developed by NASA for Space Station Freedom.

  4. Induction motor control

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.

    1990-01-01

    Electromechanical actuators developed to date have commonly ultilized permanent magnet (PM) synchronous motors. More recently switched reluctance (SR) motors have been advocated due to their robust characteristics. Implications of work which utilized induction motors and advanced control techniques are discussed. When induction motors are operated from an energy source capable of controlling voltages and frequencies independently, drive characteristics are obtained which are superior to either PM or SR motors. By synthesizing the machine frequency from a high-frequency carrier (nominally 20 kHz), high efficiencies, low distortion, and rapid torque response are available. At this time multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of aerospace actuators. This effort is based upon high-frequency power distribution and management techniques developed by NASA for Space Station Freedom.

  5. Development of replication-defective lymphocytic choriomeningitis virus vectors for the induction of potent CD8+ T cell immunity

    PubMed Central

    Flatz, Lukas; Hegazy, Ahmed N; Bergthaler, Andreas; Verschoor, Admar; Claus, Christina; Fernandez, Marylise; Gattinoni, Luca; Johnson, Susan; Kreppel, Florian; Kochanek, Stefan; van den Broek, Maries; Radbruch, Andreas; Lévy, Frédéric; Lambert, Paul-Henri; Siegrist, Claire-Anne; Restifo, Nicholas P; Löhning, Max; Ochsenbein, Adrian F; Nabel, Gary J; Pinschewer, Daniel D

    2011-01-01

    Lymphocytic choriomeningitis virus (LCMV) exhibits natural tropism for dendritic cells and represents the prototypic infection that elicits protective CD8+ T cell (cytotoxic T lymphocyte (CTL)) immunity. Here we have harnessed the immunobiology of this arenavirus for vaccine delivery. By using producer cells constitutively synthesizing the viral glycoprotein (GP), it was possible to replace the gene encoding LCMV GP with vaccine antigens to create replication-defective vaccine vectors. These rLCMV vaccines elicited CTL responses that were equivalent to or greater than those elicited by recombinant adenovirus 5 or recombinant vaccinia virus in their magnitude and cytokine profiles, and they exhibited more effective protection in several models. In contrast to recombinant adenovirus 5, rLCMV failed to elicit vector-specific antibody immunity, which facilitated re-administration of the same vector for booster vaccination. In addition, rLCMV elicited T helper type 1 CD4+ T cell responses and protective neutralizing antibodies to vaccine antigens. These features, together with low seroprevalence in humans, suggest that rLCMV may show utility as a vaccine platform against infectious diseases and cancer. PMID:20139992

  6. Memory beyond expression.

    PubMed

    Delorenzi, A; Maza, F J; Suárez, L D; Barreiro, K; Molina, V A; Stehberg, J

    2014-01-01

    The idea that memories are not invariable after the consolidation process has led to new perspectives about several mnemonic processes. In this framework, we review our studies on the modulation of memory expression during reconsolidation. We propose that during both memory consolidation and reconsolidation, neuromodulators can determine the probability of the memory trace to guide behavior, i.e. they can either increase or decrease its behavioral expressibility without affecting the potential of persistent memories to be activated and become labile. Our hypothesis is based on the findings that positive modulation of memory expression during reconsolidation occurs even if memories are behaviorally unexpressed. This review discusses the original approach taken in the studies of the crab Neohelice (Chasmagnathus) granulata, which was then successfully applied to test the hypothesis in rodent fear memory. Data presented offers a new way of thinking about both weak trainings and experimental amnesia: memory retrieval can be dissociated from memory expression. Furthermore, the strategy presented here allowed us to show in human declarative memory that the periods in which long-term memory can be activated and become labile during reconsolidation exceeds the periods in which that memory is expressed, providing direct evidence that conscious access to memory is not needed for reconsolidation. Specific controls based on the constraints of reminders to trigger reconsolidation allow us to distinguish between obliterated and unexpressed but activated long-term memories after amnesic treatments, weak trainings and forgetting. In the hypothesis discussed, memory expressibility--the outcome of experience-dependent changes in the potential to behave--is considered as a flexible and modulable attribute of long-term memories. Expression seems to be just one of the possible fates of re-activated memories.

  7. Detailed sensory memory, sloppy working memory.

    PubMed

    Sligte, Ilja G; Vandenbroucke, Annelinde R E; Scholte, H Steven; Lamme, Victor A F

    2010-01-01

    Visual short-term memory (VSTM) enables us to actively maintain information in mind for a brief period of time after stimulus disappearance. According to recent studies, VSTM consists of three stages - iconic memory, fragile VSTM, and visual working memory - with increasingly stricter capacity limits and progressively longer lifetimes. Still, the resolution (or amount of visual detail) of each VSTM stage has remained unexplored and we test this in the present study. We presented people with a change detection task that measures the capacity of all three forms of VSTM, and we added an identification display after each change trial that required people to identify the "pre-change" object. Accurate change detection plus pre-change identification requires subjects to have a high-resolution representation of the "pre-change" object, whereas change detection or identification only can be based on the hunch that something has changed, without exactly knowing what was presented before. We observed that people maintained 6.1 objects in iconic memory, 4.6 objects in fragile VSTM, and 2.1 objects in visual working memory. Moreover, when people detected the change, they could also identify the pre-change object on 88% of the iconic memory trials, on 71% of the fragile VSTM trials and merely on 53% of the visual working memory trials. This suggests that people maintain many high-resolution representations in iconic memory and fragile VSTM, but only one high-resolution object representation in visual working memory. PMID:21897823

  8. Diagnostics for induction accelerators

    SciTech Connect

    Fessenden, T.J.

    1996-04-01

    The induction accelerator was conceived by N. C. Christofilos and first realized as the Astron accelerator that operated at LLNL from the early 1960`s to the end of 1975. This accelerator generated electron beams at energies near 6 MeV with typical currents of 600 Amperes in 400 ns pulses. The Advanced Test Accelerator (ATA) built at Livermore`s Site 300 produced 10,000 Ampere beams with pulse widths of 70 ns at energies approaching 50 MeV. Several other electron and ion induction accelerators have been fabricated at LLNL and LBNL. This paper reviews the principal diagnostics developed through efforts by scientists at both laboratories for measuring the current, position, energy, and emittance of beams generated by these high current, short pulse accelerators. Many of these diagnostics are closely related to those developed for other accelerators. However, the very fast and intense current pulses often require special diagnostic techniques and considerations. The physics and design of the more unique diagnostics developed for electron induction accelerators are presented and discussed in detail.

  9. 74. AERIAL VIEW OF MEMORIAL BRIDGE AND MEMORIAL AVENUE LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    74. AERIAL VIEW OF MEMORIAL BRIDGE AND MEMORIAL AVENUE LOOKING EAST AT LINCOLN MEMORIAL. - George Washington Memorial Parkway, Along Potomac River from McLean to Mount Vernon, VA, Mount Vernon, Fairfax County, VA

  10. A taxonomy of inductive problems.

    PubMed

    Kemp, Charles; Jern, Alan

    2014-02-01

    Inductive inferences about objects, features, categories, and relations have been studied for many years, but there are few attempts to chart the range of inductive problems that humans are able to solve. We present a taxonomy of inductive problems that helps to clarify the relationships between familiar inductive problems such as generalization, categorization, and identification, and that introduces new inductive problems for psychological investigation. Our taxonomy is founded on the idea that semantic knowledge is organized into systems of objects, features, categories, and relations, and we attempt to characterize all of the inductive problems that can arise when these systems are partially observed. Recent studies have begun to address some of the new problems in our taxonomy, and future work should aim to develop unified theories of inductive reasoning that explain how people solve all of the problems in the taxonomy.

  11. Searching for repressed memory.

    PubMed

    McNally, Richard J

    2012-01-01

    This chapter summarizes the work of my research group on adults who report either repressed, recovered, or continuous memories of childhood sexual abuse (CSA) or who report no history of CSA. Adapting paradigms from cognitive psychology, we tested hypotheses inspired by both the "repressed memory" and "false memory" perspectives on recovered memories of CSA. We found some evidence for the false memory perspective, but no evidence for the repressed memory perspective. However, our work also suggests a third perspective on recovered memories that does not require the concept of repression. Some children do not understand their CSA when it occurs, and do not experience terror. Years later, they recall the experience, and understanding it as abuse, suffer intense distress. The memory failed to come to mind for years, partly because the child did not encode it as terrifying (i.e., traumatic), not because the person was unable to recall it.

  12. Emotional Memory Persists Longer than Event Memory

    ERIC Educational Resources Information Center

    Kuriyama, Kenichi; Soshi, Takahiro; Fujii, Takeshi; Kim, Yoshiharu

    2010-01-01

    The interaction between amygdala-driven and hippocampus-driven activities is expected to explain why emotion enhances episodic memory recognition. However, overwhelming behavioral evidence regarding the emotion-induced enhancement of immediate and delayed episodic memory recognition has not been obtained in humans. We found that the recognition…

  13. Associative Memory Acceptors.

    ERIC Educational Resources Information Center

    Card, Roger

    The properties of an associative memory are examined in this paper from the viewpoint of automata theory. A device called an associative memory acceptor is studied under real-time operation. The family "L" of languages accepted by real-time associative memory acceptors is shown to properly contain the family of languages accepted by one-tape,…

  14. Music, memory and emotion.

    PubMed

    Jäncke, Lutz

    2008-08-08

    Because emotions enhance memory processes and music evokes strong emotions, music could be involved in forming memories, either about pieces of music or about episodes and information associated with particular music. A recent study in BMC Neuroscience has given new insights into the role of emotion in musical memory.

  15. Memories (Children's Books).

    ERIC Educational Resources Information Center

    McKinley, Carol; Peters, Donna; Semer, Susie; White, W. Quinn; Scharer, Patricia L.

    1998-01-01

    Presents brief annotations of 46 children's books that explore memories of childhood, memories of love, keepsakes that capture those memories, memorable tales from long ago, memorable journeys, times that are painful to remember, and heroes and heroines who have provided hope and change in a troubled world. (SR)

  16. Memory and the Self

    ERIC Educational Resources Information Center

    Conway, Martin A.

    2005-01-01

    The Self-Memory System (SMS) is a conceptual framework that emphasizes the interconnectedness of self and memory. Within this framework memory is viewed as the data base of the self. The self is conceived as a complex set of active goals and associated self-images, collectively referred to as the "working self." The relationship between the…

  17. Music, memory and emotion

    PubMed Central

    Jäncke, Lutz

    2008-01-01

    Because emotions enhance memory processes and music evokes strong emotions, music could be involved in forming memories, either about pieces of music or about episodes and information associated with particular music. A recent study in BMC Neuroscience has given new insights into the role of emotion in musical memory. PMID:18710596

  18. Memory-Compatible Instruction.

    ERIC Educational Resources Information Center

    Kiewra, Kenneth A.

    1987-01-01

    Argues that most teachers do not understand the nature of human memory. Presents an informal introduction to human memory, including information on long-term retention, prior knowledge, retrieval, and cues. States that instructors can design memory-compatible instruction that makes recording and retrieval of new knowledge easier. (TW)

  19. Generation and Context Memory

    ERIC Educational Resources Information Center

    Mulligan, Neil W.; Lozito, Jeffrey P.; Rosner, Zachary A.

    2006-01-01

    Generation enhances memory for occurrence but may not enhance other aspects of memory. The present study further delineates the negative generation effect in context memory reported in N. W. Mulligan (2004). First, the negative generation effect occurred for perceptual attributes of the target item (its color and font) but not for extratarget…

  20. Low inductance gas switching.

    SciTech Connect

    Chavez, Ray; Harjes, Henry Charles III; Wallace, Zachariah; Elizondo, Juan E.

    2007-10-01

    The laser trigger switch (LTS) is a key component in ZR-type pulsed power systems. In ZR, the pulse rise time through the LTS is > 200 ns and additional stages of pulse compression are required to achieve the desired <100 ns rise time. The inductance of the LTS ({approx}500nH) in large part determines the energy transfer time through the switch and there is much to be gained in improving system performance and reducing system costs by reducing this inductance. The current path through the cascade section of the ZR LTS is at a diameter of {approx} 6-inches which is certainly not optimal from an inductance point of view. The LTS connects components of much greater diameter (typically 4-5 feet). In this LDRD the viability of switch concepts in which the diameter of cascade section is greatly increased have been investigated. The key technical question to be answered was, will the desired multi-channel behavior be maintained in a cascade section of larger diameter. This LDRD proceeded in 2 distinct phases. The original plan for the LDRD was to develop a promising switch concept and then design, build, and test a moderate scale switch which would demonstrate the key features of the concept. In phase I, a switch concept which meet all electrical design criteria and had a calculated inductance of 150 nH was developed. A 1.5 MV test switch was designed and fabrication was initiated. The LDRD was then redirected due to budgetary concerns. The fabrication of the switch was halted and the focus of the LDRD was shifted to small scale experiments designed to answer the key technical question concerning multi-channel behavior. In phase II, the Multi-channel switch test bed (MCST) was designed and constructed. The purpose of MCST was to provide a versatile, fast turn around facility for the study the multi-channel electrical breakdown behavior of a ZR type cascade switch gap in a parameter space near that of a ZR LTS. Parameter scans on source impedance, gap tilt, gap spacing and

  1. Educational inductive gravimeter

    NASA Astrophysics Data System (ADS)

    Nunn, John

    2014-01-01

    A simple inductive gravimeter constructed from a rigid plastic pipe and insulated copper wire is described. When a magnet is dropped through the vertically mounted pipe it induces small alternating voltages. These small signals are fed to the microphone input of a typical computer and sampled at a typical rate of 44.1 kHz using a custom computer program. Knowing the geometrical dimensions of the gravimeter and calculating the time intervals between peaks of the recorded signal it is possible to calculate the local gravitational acceleration (g). Limitations and improvements are discussed. Instructions are included throughout so that teachers and pupils can replicate the experiment in their own schools.

  2. NMDA receptors and memory encoding.

    PubMed

    Morris, Richard G M

    2013-11-01

    It is humbling to think that 30 years have passed since the paper by Collingridge, Kehl and McLennan showing that one of Jeff Watkins most interesting compounds, R-2-amino-5-phosphonopentanoate (d-AP5), blocked the induction of long-term potentiation in vitro at synapses from area CA3 of the hippocampus to CA1 without apparent effect on baseline synaptic transmission (Collingridge et al., 1983). This dissociation was one of the key triggers for an explosion of interest in glutamate receptors, and much has been discovered since that collectively contributes to our contemporary understanding of glutamatergic synapses - their biophysics and subunit composition, of the agonists and antagonists acting on them, and their diverse functions in different networks of the brain and spinal cord. It can be fairly said that Collingridge et al.'s (1983) observation was the stimulus that has led, on the one hand, to structural biological work at the atomic scale describing the key features of NMDA receptors that enables their coincidence function to happen; and, on the other, to work with whole animals investigating the contributions that calcium signalling via this receptor can have on rhythmical activities controlled by spinal circuits, memory encoding in the hippocampus (the topic of this article), visual cortical plasticity, sensitization in pain, and other functions. In this article, I lay out how my then interest in long-term potentiation (LTP) as a model of memory enabled me to recognise the importance of Collingridge et al.'s discovery - and how I and my colleagues endeavoured to take things forward in the area of learning and memory. This is in some respects a personal story, and I tell it as such. The idea that NMDA receptor activation is essential for memory encoding, though not for storage, took time to develop and to be accepted. Along the way, there have been confusions, challenges, and surprises surrounding the idea that activation of NMDA receptors can

  3. Induction of cytotoxic T cells and their antitumor activity in mice transgenic for carcinoembryonic antigen.

    PubMed

    Mizobata, S; Tompkins, K; Simpson, J F; Shyr, Y; Primus, F J

    2000-08-01

    In order to develop immunotherapy strategies that are based on eliciting immune responsiveness to the self-antigen, human carcinoembryonic antigen (CEA), we examined whether cytotoxic T lymphocyte (CTL) activity against CEA could be elicited in CEA-transgenic and nontransgenic mice. CEA-transgenic [C57BL/ 6-TGN(CEAGe)18FJP] and nontransgenic mice were primed with CEA-transfected syngeneic fibroblasts in combination with Corynebacterium parvum. Spleen cells from immunized mice were cultured with irradiated syngeneic MC-38 colon carcinoma cells transfected with CEA (MC-38.CEA) as stimulators prior to the measurement of CTL activity. Primed nontransgenic spleen cells showed augmented CTL activity against MC-38.CEA cells as compared with control parental MC-38 cells, nontransfected or transfected with vector only. Moreover, primed CEA transgenic spleen cells showed augmented CTL activity against MC-38.CEA cells that was similar to that observed in nontransgenic mice. All CTL clones derived from either transgenic or nontransgenic mice showed cross-reactivity with MC-38 cells expressing the CEA-related antigen, nonspecific cross-reacting antigen, but not biliary glycoprotein. CEA-specific CTL clones were not identified. Adoptive transfer of cloned CTL resulted in inhibition of MC-38.CEA but not MC-38.BGP tumor growth. Tumor cures were elicited in mice treated with a combination of cloned CTL and cyclophosphamide. Histopathological examination of CEA-expressing colons from either immunized mice or recipients of cloned CTL did not reveal any autoimmune reactions. These studies demonstrate that CTL recognizing cross-reactive class I epitopes on the CEA molecule can be induced in transgenic mice. The expression of these epitopes on tumor cells creates effective targets for CTL in vivo without inducing adverse reactions in CEA-expressing normal tissues. Since anti-CEA CTL have been generated in humans, CEA-transgenic mice may be a useful model to study vaccines that are based

  4. Induction linear accelerators

    NASA Astrophysics Data System (ADS)

    Birx, Daniel

    1992-03-01

    Among the family of particle accelerators, the Induction Linear Accelerator is the best suited for the acceleration of high current electron beams. Because the electromagnetic radiation used to accelerate the electron beam is not stored in the cavities but is supplied by transmission lines during the beam pulse it is possible to utilize very low Q (typically<10) structures and very large beam pipes. This combination increases the beam breakup limited maximum currents to of order kiloamperes. The micropulse lengths of these machines are measured in 10's of nanoseconds and duty factors as high as 10-4 have been achieved. Until recently the major problem with these machines has been associated with the pulse power drive. Beam currents of kiloamperes and accelerating potentials of megavolts require peak power drives of gigawatts since no energy is stored in the structure. The marriage of liner accelerator technology and nonlinear magnetic compressors has produced some unique capabilities. It now appears possible to produce electron beams with average currents measured in amperes, peak currents in kiloamperes and gradients exceeding 1 MeV/meter, with power efficiencies approaching 50%. The nonlinear magnetic compression technology has replaced the spark gap drivers used on earlier accelerators with state-of-the-art all-solid-state SCR commutated compression chains. The reliability of these machines is now approaching 1010 shot MTBF. In the following paper we will briefly review the historical development of induction linear accelerators and then discuss the design considerations.

  5. Induction of Ovulation

    PubMed Central

    Lamb, Emmet J.

    1965-01-01

    Every effort should be made to find the cause of anovulation since specific therapy directed at correction of a specific hormonal deficiency or excess is, of course, much more effective than any empiric treatment. Moreover, some patients with disorders of ovulation may have serious, even fatal, underlying disorders. The use of thyroid or cortisone has been disappointing except in the treatment of an overt deficiency of thyroid or cortisone or an excess of adrenal androgens. Estrogens and progestational agents have not been consistently effective in the induction of ovulation. The use of clomiphene citrate, which apparently stimulates the release of gonadotropins, and the use of purified gonadotropins of human origin have been quite successful in the induction of ovulation in a variety of disorders of ovarian function. Because of real and potential hazards, the use of these new agents should be restricted to women for whom pregnancy is the primary goal or in whom standard methods of therapy have failed. Neither drug has been released by the Food and Drug Administration for routine clinical use. PMID:14336790

  6. A multiplexed quantum memory.

    PubMed

    Lan, S-Y; Radnaev, A G; Collins, O A; Matsukevich, D N; Kennedy, T A; Kuzmich, A

    2009-08-01

    A quantum repeater is a system for long-distance quantum communication that employs quantum memory elements to mitigate optical fiber transmission losses. The multiplexed quantum memory (O. A. Collins, S. D. Jenkins, A. Kuzmich, and T. A. B. Kennedy, Phys. Rev. Lett. 98, 060502 (2007)) has been shown theoretically to reduce quantum memory time requirements. We present an initial implementation of a multiplexed quantum memory element in a cold rubidium gas. We show that it is possible to create atomic excitations in arbitrary memory element pairs and demonstrate the violation of Bell's inequality for light fields generated during the write and read processes.

  7. Inositol polyphosphate multikinase is a transcriptional coactivator required for immediate early gene induction.

    PubMed

    Xu, Risheng; Paul, Bindu D; Smith, Dani R; Tyagi, Richa; Rao, Feng; Khan, A Basit; Blech, Daniel J; Vandiver, M Scott; Harraz, Maged M; Guha, Prasun; Ahmed, Ishrat; Sen, Nilkantha; Gallagher, Michela; Snyder, Solomon H

    2013-10-01

    Profound induction of immediate early genes (IEGs) by neural activation is a critical determinant for plasticity in the brain, but intervening molecular signals are not well characterized. We demonstrate that inositol polyphosphate multikinase (IPMK) acts noncatalytically as a transcriptional coactivator to mediate induction of numerous IEGs. IEG induction by electroconvulsive stimulation is virtually abolished in the brains of IPMK-deleted mice, which also display deficits in spatial memory. Neural activity stimulates binding of IPMK to the histone acetyltransferase CBP and enhances its recruitment to IEG promoters. Interestingly, IPMK regulation of CBP recruitment and IEG induction does not require its catalytic activities. Dominant-negative constructs, which prevent IPMK-CBP binding, substantially decrease IEG induction. As IPMK is ubiquitously expressed, its epigenetic regulation of IEGs may influence diverse nonneural and neural biologic processes.

  8. Induction of anaesthesia in children.

    PubMed

    Boezaart, A P; van Hasselt, C H

    1987-05-16

    Induction of anaesthesia in children in the age group 2-6 years is a special challenge. In order to minimise emotional and physical stress during induction of anaesthesia by gas inhalation, a toy telephone has been modified to deliver induction gases to the mouthpiece while taped nursery stories can be heard from a small speaker placed in the earpiece. The child holds the hand set and listens to a suitable story, while appropriate concentrations of inhalation agents are adjusted inconspicuously. PMID:3576386

  9. Immunological memory is associative

    SciTech Connect

    Smith, D.J.; Forrest, S.; Perelson, A.S.

    1996-12-31

    The purpose of this paper is to show that immunological memory is an associative and robust memory that belongs to the class of sparse distributed memories. This class of memories derives its associative and robust nature by sparsely sampling the input space and distributing the data among many independent agents. Other members of this class include a model of the cerebellar cortex and Sparse Distributed Memory (SDM). First we present a simplified account of the immune response and immunological memory. Next we present SDM, and then we show the correlations between immunological memory and SDM. Finally, we show how associative recall in the immune response can be both beneficial and detrimental to the fitness of an individual.

  10. Flexible kernel memory.

    PubMed

    Nowicki, Dimitri; Siegelmann, Hava

    2010-06-11

    This paper introduces a new model of associative memory, capable of both binary and continuous-valued inputs. Based on kernel theory, the memory model is on one hand a generalization of Radial Basis Function networks and, on the other, is in feature space, analogous to a Hopfield network. Attractors can be added, deleted, and updated on-line simply, without harming existing memories, and the number of attractors is independent of input dimension. Input vectors do not have to adhere to a fixed or bounded dimensionality; they can increase and decrease it without relearning previous memories. A memory consolidation process enables the network to generalize concepts and form clusters of input data, which outperforms many unsupervised clustering techniques; this process is demonstrated on handwritten digits from MNIST. Another process, reminiscent of memory reconsolidation is introduced, in which existing memories are refreshed and tuned with new inputs; this process is demonstrated on series of morphed faces.

  11. Child maltreatment and memory.

    PubMed

    Goodman, Gail S; Quas, Jodi A; Ogle, Christin M

    2010-01-01

    Exposure to childhood trauma, especially child maltreatment, has important implications for memory of emotionally distressing experiences. These implications stem from cognitive, socio-emotional, mental health, and neurobiological consequences of maltreatment and can be at least partially explained by current theories concerning the effects of childhood trauma. In this review, two main hypotheses are advanced: (a) Maltreatment in childhood is associated with especially robust memory for emotionally distressing material in many individuals, but (b) maltreatment can impair memory for such material in individuals who defensively avoid it. Support for these hypotheses comes from research on child abuse victims' memory and suggestibility regarding distressing but nonabusive events, memory for child abuse itself, and autobiographical memory. However, more direct investigations are needed to test precisely when and how childhood trauma affects memory for emotionally significant, distressing experiences. Legal implications and future directions are discussed.

  12. Memory access in shared virtual memory

    SciTech Connect

    Berrendorf, R.

    1992-09-01

    Shared virtual memory (SVM) is a virtual memory layer with a single address space on top of a distributed real memory on parallel computers. We examine the behavior and performance of SVM running a parallel program with medium-grained, loop-level parallelism on top of it. A simulator for the underlying parallel architecture can be used to examine the behavior of SVM more deeply. The influence of several parameters, such as the number of processors, page size, cold or warm start, and restricted page replication, is studied.

  13. Memory access in shared virtual memory

    SciTech Connect

    Berrendorf, R. )

    1992-01-01

    Shared virtual memory (SVM) is a virtual memory layer with a single address space on top of a distributed real memory on parallel computers. We examine the behavior and performance of SVM running a parallel program with medium-grained, loop-level parallelism on top of it. A simulator for the underlying parallel architecture can be used to examine the behavior of SVM more deeply. The influence of several parameters, such as the number of processors, page size, cold or warm start, and restricted page replication, is studied.

  14. Divergent creative thinking in young and older adults: Extending the effects of an episodic specificity induction.

    PubMed

    Madore, Kevin P; Jing, Helen G; Schacter, Daniel L

    2016-08-01

    Recent research has suggested that an episodic specificity induction-brief training in recollecting the details of a past experience-enhances divergent creative thinking on the alternate uses task (AUT) in young adults, without affecting performance on tasks thought to involve little divergent thinking; however, the generalizability of these results to other populations and tasks is unknown. In the present experiments, we examined whether the effects of an episodic specificity induction would extend to older adults and a different index of divergent thinking, the consequences task. In Experiment 1, the specificity induction significantly enhanced divergent thinking on the AUT in both young and older adults, as compared with a control induction not requiring specific episodic retrieval; performance on a task involving little divergent thinking (generating associates for common objects) did not vary as a function of induction. No overall age-related differences were observed on either task. In Experiment 2, the specificity induction significantly enhanced divergent thinking (in terms of generating consequences of novel scenarios) in young adults, relative to another control induction not requiring episodic retrieval. To examine the types of creative ideas affected by the induction, the participants in both experiments also labeled each of their divergent-thinking responses as an "old idea" from memory or a "new idea" from imagination. New, and to some extent old, ideas were significantly boosted following the specificity induction relative to the control. These experiments provide novel evidence that an episodic specificity induction can boost divergent thinking in young and older adults, and indicate that episodic memory is involved in multiple divergent-thinking tasks. PMID:27001170

  15. Divergent creative thinking in young and older adults: Extending the effects of an episodic specificity induction.

    PubMed

    Madore, Kevin P; Jing, Helen G; Schacter, Daniel L

    2016-08-01

    Recent research has suggested that an episodic specificity induction-brief training in recollecting the details of a past experience-enhances divergent creative thinking on the alternate uses task (AUT) in young adults, without affecting performance on tasks thought to involve little divergent thinking; however, the generalizability of these results to other populations and tasks is unknown. In the present experiments, we examined whether the effects of an episodic specificity induction would extend to older adults and a different index of divergent thinking, the consequences task. In Experiment 1, the specificity induction significantly enhanced divergent thinking on the AUT in both young and older adults, as compared with a control induction not requiring specific episodic retrieval; performance on a task involving little divergent thinking (generating associates for common objects) did not vary as a function of induction. No overall age-related differences were observed on either task. In Experiment 2, the specificity induction significantly enhanced divergent thinking (in terms of generating consequences of novel scenarios) in young adults, relative to another control induction not requiring episodic retrieval. To examine the types of creative ideas affected by the induction, the participants in both experiments also labeled each of their divergent-thinking responses as an "old idea" from memory or a "new idea" from imagination. New, and to some extent old, ideas were significantly boosted following the specificity induction relative to the control. These experiments provide novel evidence that an episodic specificity induction can boost divergent thinking in young and older adults, and indicate that episodic memory is involved in multiple divergent-thinking tasks.

  16. Induction Linac Pulsers

    SciTech Connect

    Faltens, Andris

    2011-01-07

    The pulsers used in most of the induction linacs evolved from the very large body of work that was done in the U.S. and Great Britain during the development of the pulsed magnetron for radar. The radar modulators started at {approx}100 kW and reached >10 MW by 1945. A typical pulse length was 1 {mu}s at a repetition rate of 1,000 pps. A very comprehensive account of the modulator development is Pulse Generators by Lebacqz and Glasoe, one of the Radiation Laboratory Series. There are many permutations of possible modulators, two of the choices being tube type and line type. In earlier notes I wrote that technically the vacuum tube pulser met all of our induction linac needs, in the sense that a number of tubes, in series and parallel if required, could produce our pulses, regulate their voltage, be useable in feed-forward correctors, and provide a low source impedance. At a lower speed, an FET array is similar, and we have obtained and tested a large array capable of >10 MW switching. A modulator with an electronically controlled output only needs a capacitor for energy storage and in a switched mode can transfer the energy from the capacitor to the load at high efficiency. Driving a full size Astron induction core and a simulated resistive 'beam load' we achieved >50% efficiency. These electronically controlled output pulses can produce the pulses we desire but are not used because of their high cost. The second choice, the line type pulser, visually comprises a closing switch and a distributed or a lumped element transmission line. The typical switch cannot open or stop conducting after the desired pulse has been produced, and consequently all of the initially stored energy is dissipated. This approximately halves the efficiency, and the original cost estimating program LIACEP used this factor of two, even though our circuits are usually worse, and even though our inveterate optimists often omit it. The 'missing' energy is that which is reflected back into the

  17. Comprehensive Teacher Induction: Linking Teacher Induction to Theory

    ERIC Educational Resources Information Center

    Keilwitz, Heather A.

    2014-01-01

    Teacher retention is a wide concern in education and in response school districts throughout the United States are developing more comprehensive teacher induction programs. Components of teacher induction programs that have assisted with successful teacher development include release time for teacher observation, assignment of a knowledgeable…

  18. Working Memory and Dynamic Measures of Analogical Reasoning as Predictors of Children's Math and Reading Achievement

    ERIC Educational Resources Information Center

    Stevenson, Claire E.; Bergwerff, Catharina E.; Heiser, Willem J.; Resing, Wilma C. M.

    2014-01-01

    Working memory and inductive reasoning ability each appear related to children's achievement in math and reading. Dynamic measures of reasoning, based on an assessment procedure including feedback, may provide additional predictive value. The aim of this study was to investigate whether working memory and dynamic measures of analogical…

  19. Programming Inductive Proofs

    NASA Astrophysics Data System (ADS)

    Pientka, Brigitte

    In this paper, we present an overview to programming with proofs in the reasoning framework, Beluga. Beluga supports the specification of formal systems given by axioms and inference rules within the logical framework LF. It also supports implementing proofs about formal systems as dependently typed recursive functions. What distinguishes Beluga from other frameworks is that it not only represents binders using higher-order abstract syntax, but directly supports reasoning with contexts and contextual objects. Contextual types allows us to characterize precisely hypothetical and parametric derivations, i.e. derivations which depend on variables and assumptions, and lead to a direct and elegant implementation of inductive proofs as recursive functions. Because of the intrinsic support for binders and contexts, one can think of the design of Beluga as the most advanced technology for specifying and prototyping formal systems together with their meta-theory.

  20. Borehole induction coil transmitter

    SciTech Connect

    Holladay, Gale; Wilt, Michael J.

    2002-01-01

    A borehole induction coil transmitter which is a part of a cross-borehole electromagnetic field system that is used for underground imaging applications. The transmitter consists of four major parts: 1) a wound ferrite or mu-metal core, 2) an array of tuning capacitors, 3) a current driver circuit board, and 4) a flux monitor. The core is wound with several hundred turns of wire and connected in series with the capacitor array, to produce a tuned coil. This tuned coil uses internal circuitry to generate sinusoidal signals that are transmitted through the earth to a receiver coil in another borehole. The transmitter can operate at frequencies from 1-200 kHz and supplies sufficient power to permit the field system to operate in boreholes separated by up to 400 meters.

  1. Inductive System Health Monitoring

    NASA Technical Reports Server (NTRS)

    Iverson, David L.

    2004-01-01

    The Inductive Monitoring System (IMS) software was developed to provide a technique to automatically produce health monitoring knowledge bases for systems that are either difficult to model (simulate) with a computer or which require computer models that are too complex to use for real time monitoring. IMS uses nominal data sets collected either directly from the system or from simulations to build a knowledge base that can be used to detect anomalous behavior in the system. Machine learning and data mining techniques are used to characterize typical system behavior by extracting general classes of nominal data from archived data sets. IMS is able to monitor the system by comparing real time operational data with these classes. We present a description of learning and monitoring method used by IMS and summarize some recent IMS results.

  2. Kinetic inductance magnetometer.

    PubMed

    Luomahaara, Juho; Vesterinen, Visa; Grönberg, Leif; Hassel, Juha

    2014-09-10

    Sensing ultra-low magnetic fields has various applications in the fields of science, medicine and industry. There is a growing need for a sensor that can be operated in ambient environments where magnetic shielding is limited or magnetic field manipulation is involved. To this end, here we demonstrate a new magnetometer with high sensitivity and wide dynamic range. The device is based on the current nonlinearity of superconducting material stemming from kinetic inductance. A further benefit of our approach is of extreme simplicity: the device is fabricated from a single layer of niobium nitride. Moreover, radio frequency multiplexing techniques can be applied, enabling the simultaneous readout of multiple sensors, for example, in biomagnetic measurements requiring data from large sensor arrays.

  3. Inductive Position Sensor

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert C. (Inventor); Simmons, Stephen M. (Inventor)

    2015-01-01

    An inductive position sensor uses three parallel inductors, each of which has an axial core that is an independent magnetic structure. A first support couples first and second inductors and separate them by a fixed distance. A second support coupled to a third inductor disposed between the first and second inductors. The first support and second support are configured for relative movement as distance changes from the third inductor to each of the first and second inductors. An oscillating current is supplied to the first and second inductors. A device measures a phase component of a source voltage generating the oscillating current and a phase component of voltage induced in the third inductor when the oscillating current is supplied to the first and second inductors such that the phase component of the voltage induced overlaps the phase component of the source voltage.

  4. Tolerance Induction in Liver.

    PubMed

    Karimi, M H; Geramizadeh, B; Malek-Hosseini, S A

    2015-01-01

    Liver is an exclusive anatomical and immunological organ that displays a considerable tolerance effect. Liver allograft acceptance is shown to occur spontaneously within different species. Although in human transplant patients tolerance is rarely seen, the severity level and cellular mechanisms of transplant rejection vary. Non-paranchymal liver cells, including Kupffer cells, liver sinusoidal endothelial cells, hepatic stellate cells, and resident dendritic cells may participate in liver tolerogenicity. The mentioned cells secret anti-inflammatory cytokines such as TGF-β and IL-10 and express negative co-stimulatory molecules like PD-L1 to mediate immunosuppression. Other mechanisms such as microchimerism, soluble major histocompatibility complex and regulatory T cells may take part in tolerance induction. Understanding the mechanisms involved in liver transplant rejection/tolerance helps us to improve therapeutic options to induce hepatic tolerance. PMID:26082828

  5. Memory bistable mechanisms of organic memory devices

    NASA Astrophysics Data System (ADS)

    Lee, Ching-Ting; Yu, Li-Zhen; Chen, Hung-Chun

    2010-07-01

    To investigate the memory bistable mechanisms of organic memory devices, the structure of [top Au anode/9,10-di(2-naphthyl)anthracene (ADN) active layer/bottom Au cathode] was deposited using a thermal deposition system. The Au atoms migrated into the ADN active layer was observed from the secondary ion mass spectrometry. The density of 9.6×1016 cm-3 and energy level of 0.553 eV of the induced trapping centers caused by the migrated Au atoms in the ADN active layer were calculated. The induced trapping centers did not influence the carrier injection barrier height between Au and ADN active layer. Therefore, the memory bistable behaviors of the organic memory devices were attributed to the induced trapping centers. The energy diagram was established to verify the mechanisms.

  6. Induction of pluripotency.

    PubMed

    Heffernan, Corey; Liu, Jun; Sumer, Huseyin; Malaver-Ortega, Luis F; Verma, Rajneesh; Carvalho, Edmund; Verma, Paul J

    2013-01-01

    The molecular and phenotypic irreversibility of mammalian cell differentiation was a fundamental principle of developmental biology at least until the 1980s, despite numerous reports dating back to the 1950s of the induction of pluripotency in amphibian cells by nuclear transfer (NT). Landmark reports in the 1980s and 1990s in sheep progressively challenged this dogmatic assumption; firstly, embryonic development of reconstructed embryos comprising whole (donor) blastomeres fused to enucleated oocytes, and famously, the cloning of Dolly from a terminally differentiated cell. Thus, the intrinsic ability of oocyte-derived factors to reverse the differentiated phenotype was confirmed. The concomitant elucidation of methods for human embryonic stem cell isolation and cultivation presented opportunities for therapeutic cell replacement strategies, particularly through NT of patient nuclei to enucleated oocytes for subsequent isolation of patient-specific (autologous), pluripotent cells from the resulting blastocysts. Associated logistical limitations of working with human oocytes, in addition to ethical and moral objections prompted exploration of alternative approaches to generate autologous stem cells for therapy, utilizing the full repertoire of factors characteristic of pluripotency, primarily through cell fusion and use of pluripotent cell extracts. Stunningly, in 2006, Japanese scientists described somatic cell reprogramming through delivery of four key factors (identified through a deductive approach from 24 candidate genes). Although less efficient than previous approaches, much of current stem cell research adopts this focused approach to cell reprogramming and (autologous) cell therapy. This chapter is a quasi-historical commentary of the various aforementioned approaches for the induction of pluripotency in lineage-committed cells, and introduces transcriptional and epigenetic changes occurring during reprogramming.

  7. Induction of pluripotency.

    PubMed

    Heffernan, Corey; Liu, Jun; Sumer, Huseyin; Malaver-Ortega, Luis F; Verma, Rajneesh; Carvalho, Edmund; Verma, Paul J

    2013-01-01

    The molecular and phenotypic irreversibility of mammalian cell differentiation was a fundamental principle of developmental biology at least until the 1980s, despite numerous reports dating back to the 1950s of the induction of pluripotency in amphibian cells by nuclear transfer (NT). Landmark reports in the 1980s and 1990s in sheep progressively challenged this dogmatic assumption; firstly, embryonic development of reconstructed embryos comprising whole (donor) blastomeres fused to enucleated oocytes, and famously, the cloning of Dolly from a terminally differentiated cell. Thus, the intrinsic ability of oocyte-derived factors to reverse the differentiated phenotype was confirmed. The concomitant elucidation of methods for human embryonic stem cell isolation and cultivation presented opportunities for therapeutic cell replacement strategies, particularly through NT of patient nuclei to enucleated oocytes for subsequent isolation of patient-specific (autologous), pluripotent cells from the resulting blastocysts. Associated logistical limitations of working with human oocytes, in addition to ethical and moral objections prompted exploration of alternative approaches to generate autologous stem cells for therapy, utilizing the full repertoire of factors characteristic of pluripotency, primarily through cell fusion and use of pluripotent cell extracts. Stunningly, in 2006, Japanese scientists described somatic cell reprogramming through delivery of four key factors (identified through a deductive approach from 24 candidate genes). Although less efficient than previous approaches, much of current stem cell research adopts this focused approach to cell reprogramming and (autologous) cell therapy. This chapter is a quasi-historical commentary of the various aforementioned approaches for the induction of pluripotency in lineage-committed cells, and introduces transcriptional and epigenetic changes occurring during reprogramming. PMID:23696349

  8. Psychophysiology of prospective memory.

    PubMed

    Rothen, Nicolas; Meier, Beat

    2014-01-01

    Prospective memory involves the self-initiated retrieval of an intention upon an appropriate retrieval cue. Cue identification can be considered as an orienting reaction and may thus trigger a psychophysiological response. Here we present two experiments in which skin conductance responses (SCRs) elicited by prospective memory cues were compared to SCRs elicited by aversive stimuli to test whether a single prospective memory cue triggers a similar SCR as an aversive stimulus. In Experiment 2 we also assessed whether cue specificity had a differential influence on prospective memory performance and on SCRs. We found that detecting a single prospective memory cue is as likely to elicit a SCR as an aversive stimulus. Missed prospective memory cues also elicited SCRs. On a behavioural level, specific intentions led to better prospective memory performance. However, on a psychophysiological level specificity had no influence. More generally, the results indicate reliable SCRs for pr