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Sample records for hiv-derived t-lymphocyte epitopes

  1. Development of a dendritic cell vaccine encoding multiple cytotoxic T lymphocyte epitopes targeting hepatitis C virus.

    PubMed

    Zhou, Yun; Zhao, Futao; Chen, Lin; Ma, Li; Wang, Yu; He, Yu; Ma, Zhiyuan; Liu, Haili; Guo, Yonghong; Zhang, Ying; Yao, Zhiqiang; Hao, Chunqiu; Jia, Zhansheng

    2013-10-01

    The aim of the present study was to develop a dendritic cell (DC) vaccine encoding hepatitis C virus (HCV) multiple cytotoxic T lymphocyte (CTL) epitopes that can stimulate T cell responses in vitro, and can be used for immunization in vivo. DCs were infected with recombinant replication-defective adenoviruses (Ads) expressing 2 HCV sequences fused with green fluorescent protein (GFP) and FLAG tags. One sequence (sequence 1) contained the HCV CTL epitopes, NS4B 1793-1801 and P7 774-782, as well as the HCV Th epitope, NS3 1248-1261. A second sequence (sequence 2) was the positive epitope control which contained HCV core 35-44, core 132-140 and NS3 1248-1261. The efficiency of infection was detected by flow cytometry and the expression of HCV epitopes in the DCs was confirmed by RT-PCR and western blot analysis. Ad infection significantly enhanced DC maturation and interleukin (IL)-12p70 production, resulting in T cell proliferation and increased interferon-γ secretion. The CTLs stimulated by Ad-infected DCs specifically killed Huh7.5 human hepatoma cells. The recombinant Ad-expressing multiple CTL HCV epitopes effectively infected the DCs in vitro and promoted T cell antiviral immune responses, thereby laying the foundation for the development of anti-HCV DC vaccines. PMID:23934073

  2. 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

  3. Elicitation from virus-naive individuals of cytotoxic T lymphocytes directed against conserved HIV-1 epitopes

    PubMed Central

    Reche, Pedro A; Keskin, Derin B; Hussey, Rebecca E; Ancuta, Petronela; Gabuzda, Dana; Reinherz, Ellis L

    2006-01-01

    Cytotoxic T lymphocytes (CTL) protect against viruses including HIV-1. To avoid viral escape mutants that thwart immunity, we chose 25 CTL epitopes defined in the context of natural infection with functional and/or structural constraints that maintain sequence conservation. By combining HLA binding predictions with knowledge concerning HLA allele frequencies, a metric estimating population protection coverage (PPC) was computed and epitope pools assembled. Strikingly, only a minority of immunocompetent HIV-1 infected individuals responds to pools with PPC >95%. In contrast, virus-naive individuals uniformly expand IFNγ producing cells and mount anti-HIV-1 cytolytic activity. This disparity suggests a vaccine design paradigm shift from infected to normal subjects. PMID:16674822

  4. Novel epitopes identified from efflux pumps of Mycobacterium tuberculosis could induce cytotoxic T lymphocyte response

    PubMed Central

    Zhai, Ming-xia; Chen, Fei; Zhao, Yuan-yuan; Wu, Ya-hong; Li, Guo-dong; Qi, Yuan-ming

    2015-01-01

    Overcoming drug-resistance is one of the major challenges to control tuberculosis (TB). The up-regulation of efflux pumps is one common mechanism that leads to drug-resistance. Therefore, immunotherapy targeting these efflux pump antigens could be promising strategy to be combined with current chemotherapy. Considering that CD8+ cytotoxic T lymphocytes (CTLs) induced by antigenic peptides (epitopes) could elicit HLA-restricted anti-TB immune response, efflux pumps from classical ABC family (Mycobacterium tuberculosis, Mtb) were chosen as target antigens to identify CTL epitopes. HLA-A2 restricted candidate peptides from Rv2937, Rv2686c and Rv2687c of Mycobacterium tuberculosis were predicted, synthesized and tested. Five peptides could induce IFN-γ release and cytotoxic activity in PBMCs from HLA-A2+ PPD+ donors. Results from HLA-A2/Kb transgenic mice immunization assay suggested that four peptides Rv2937-p168, Rv2937-p266, Rv2686c-p151, and Rv2686c-p181 could induce significant CTL response in vivo. These results suggested that these novel epitopes could be used as immunotherapy candidates to TB drug-resistance. PMID:26417538

  5. Rational Design of a Multiepitope Vaccine Encoding T-Lymphocyte Epitopes for Treatment of Chronic Hepatitis B Virus Infections▿

    PubMed Central

    Depla, Erik; Van der Aa, Annegret; Livingston, Brian D.; Crimi, Claire; Allosery, Koen; De Brabandere, Veronique; Krakover, Jonathan; Murthy, Sidharta; Huang, Manley; Power, Scott; Babé, Lilia; Dahlberg, Carol; McKinney, Denise; Sette, Alessandro; Southwood, Scott; Philip, Ramilla; Newman, Mark J.; Meheus, Lydie

    2008-01-01

    Protein sequences from multiple hepatitis B virus (HBV) isolates were analyzed for the presence of amino acid motifs characteristic of cytotoxic T-lymphocyte (CTL) and helper T-lymphocyte (HTL) epitopes with the goal of identifying conserved epitopes suitable for use in a therapeutic vaccine. Specifically, sequences bearing HLA-A1, -A2, -A3, -A24, -B7, and -DR supertype binding motifs were identified, synthesized as peptides, and tested for binding to soluble HLA. The immunogenicity of peptides that bound with moderate to high affinity subsequently was assessed using HLA transgenic mice (CTL) and HLA cross-reacting H-2bxd (BALB/c × C57BL/6J) mice (HTL). Through this process, 30 CTL and 16 HTL epitopes were selected as a set that would be the most useful for vaccine design, based on epitope conservation among HBV sequences and HLA-based predicted population coverage in diverse ethnic groups. A plasmid DNA-based vaccine encoding the epitopes as a single gene product, with each epitope separated by spacer residues to enhance appropriate epitope processing, was designed. Immunogenicity testing in mice demonstrated the induction of multiple CTL and HTL responses. Furthermore, as a complementary approach, mass spectrometry allowed the identification of correctly processed and major histocompatibility complex-presented epitopes from human cells transfected with the DNA plasmid. A heterologous prime-boost immunization with the plasmid DNA and a recombinant MVA gave further enhancement of the immune responses. Thus, a multiepitope therapeutic vaccine candidate capable of stimulating those cellular immune responses thought to be essential for controlling and clearing HBV infection was successfully designed and evaluated in vitro and in HLA transgenic mice. PMID:17942551

  6. Differential Influence on Cytotoxic T Lymphocyte Epitope Presentation by Controlled Expression of Either Proteasome Immunosubunits or Pa28

    PubMed Central

    van Hall, Thorbald; Sijts, Alice; Camps, Marcel; Offringa, Rienk; Melief, Cornelis; Kloetzel, Peter-M.; Ossendorp, Ferry

    2000-01-01

    The proteasome is the principal provider of major histocompatibility complex (MHC) class I–presented peptides. Interferon (IFN)-γ induces expression of three catalytically active proteasome subunits (LMP2, LMP7, and MECL-1) and the proteasome-associated activator PA28. These molecules are thought to optimize the generation of MHC class I–presented peptides. However, known information on their contribution in vivo is very limited. Here, we examined the antigen processing of two murine leukemia virus-encoded cytotoxic T lymphocyte (CTL) epitopes in murine cell lines equipped with a tetracycline-controlled, IFN-γ–independent expression system. We thus were able to segregate the role of the immunosubunits from the role of PA28. The presence of either immunosubunits or PA28 did not alter the presentation of a subdominant murine leukemia virus (MuLV)-derived CTL epitope. However, the presentation of the immunodominant MuLV-derived epitope was markedly enhanced upon induction of each of these two sets of genes. Thus, the IFN-γ–inducible proteasome subunits and PA28 can independently enhance antigen presentation of some CTL epitopes. Our data show that tetracycline-regulated expression of PA28 increases CTL epitope generation without affecting the 20S proteasome composition or half-life. The differential effect of these IFN-γ–inducible proteins on MHC class I processing may have a decisive influence on the quality of the CTL immune response. PMID:10952718

  7. Efficient Generation of a Hepatitis B Virus Cytotoxic T Lymphocyte Epitope Requires the Structural Features of Immunoproteasomes

    PubMed Central

    Sijts, Alice J.A.M.; Ruppert, Thomas; Rehermann, Barbara; Schmidt, Marion; Koszinowski, Ulrich; Kloetzel, Peter-M.

    2000-01-01

    Interferon (IFN)-γ–induced cells express the proteasome subunits low molecular weight protein (LMP)2, LMP7, and MECL-1 (multicatalytic endopeptidase complex–like 1), leading to the formation of immunoproteasomes. Although these subunits are thought to optimize MHC class I antigen processing, the extent of their role and the mechanistic aspects involved remain unclear. Herein, we study the proteolytic generation of an human histocompatibility leukocyte antigen (HLA)-Aw68–restricted hepatitis B virus core antigen (HBcAg) cytotoxic T lymphocyte (CTL) epitope that is recognized by peripheral blood lymphocytes from patients with acute self-limited but not chronic hepatitis B virus (HBV). Immunological data suggest that IFN-γ–induced rather than uninduced HeLa cells process and present the HBV CTL epitope upon infection with HBcAg-expressing vaccinia viruses. Analyses of 20S proteasome digests of synthetic polypeptides covering the antigenic HBcAg peptide demonstrate that only immunoproteasomes efficiently perform the cleavages needed for the liberation of this HBV CTL epitope. Although the concerted presence of the three immunosubunits appears essential, we find that both catalytically active LMP7 and inactive LMP7 T1A support CTL epitope generation. We conclude that LMP7 influences the structural features of 20S proteasomes, thereby enhancing the activity of the LMP2 and MECL-1 catalytic sites, which provide cleavage specificity. Thus, LMP7 incorporation is of greater functional importance for the generation of an HBV CTL epitope than cleavage specificity. PMID:10662796

  8. Generation of cytotoxic T lymphocytes against immunorecessive epitopes after multiple immunizations with adenovirus vectors is dependent on haplotype.

    PubMed

    Sparer, T E; Wynn, S G; Clark, D J; Kaplan, J M; Cardoza, L M; Wadsworth, S C; Smith, A E; Gooding, L R

    1997-03-01

    Currently, adenovirus (Ad) is being considered as a vector for the treatment of cystic fibrosis as well as other diseases. However, the cytotoxic T lymphocyte (CTL) response to Ad could limit the effectiveness of such approaches. Since the CTL response to virus infection is often focused on one or a few immunodominant epitopes, one approach to circumvent this response is to create vectors that lack these immunodominant epitopes. The effectiveness of this approach was tested by immunizing mice with human group C adenoviruses. Three mouse strains (C57BL/10SnJ [H-2b], C3HeB/FeJ [H-2k], and BALB/cByJ [H-2d]) were immunized with wild-type Ad or Ad vectors lacking the immunodominant antigen(s), and the CTL responses were measured. In C57BL/10 (B10) mice, a single inoculation intraperitoneally (i.p.) led to the recognition of an immunodominant antigen in E1A. When B10 mice were inoculated multiple times either i.p. or intranasally with wild-type Ad or an Ad vector lacking most of the E1 region, subdominant epitopes outside this region were recognized. In contrast, C3H mice inoculated with wild-type Ad recognized an epitope mapping within E1B. When inoculated twice with Ad vectors lacking both E1A and E1B, no immunorecessive epitopes were recognized. The immune response to Ad in BALB/c mice was more complex. CTLs from BALB/c mice inoculated i.p. with wild-type Ad recognized E1B in the context of the major histocompatibility complex (MHC) class I Dd allele and a region outside E1 associated with the Kd allele. When BALB/c mice were inoculated with E1-deleted Ad vectors, only the immunodominant Kd-restricted epitope was recognized, and Dd-restricted CTLs did not develop. This report indicates that the emergence of CTLs against immunorecessive epitopes following multiple administrations of Ad vectors lacking immunodominant antigens is dependent on haplotype and could present an obstacle to gene therapy in an MHC-diverse human population. PMID:9032363

  9. NetMHCstab - predicting stability of peptide-MHC-I complexes; impacts for cytotoxic T lymphocyte epitope discovery.

    PubMed

    Jørgensen, Kasper W; Rasmussen, Michael; Buus, Søren; Nielsen, Morten

    2014-01-01

    Major histocompatibility complex class I (MHC-I) molecules play an essential role in the cellular immune response, presenting peptides to cytotoxic T lymphocytes (CTLs) allowing the immune system to scrutinize ongoing intracellular production of proteins. In the early 1990s, immunogenicity and stability of the peptide-MHC-I (pMHC-I) complex were shown to be correlated. At that time, measuring stability was cumbersome and time consuming and only small data sets were analysed. Here, we investigate this fairly unexplored area on a large scale compared with earlier studies. A recent small-scale study demonstrated that pMHC-I complex stability was a better correlate of CTL immunogenicity than peptide-MHC-I affinity. We here extended this study and analysed a total of 5509 distinct peptide stability measurements covering 10 different HLA class I molecules. Artificial neural networks were used to construct stability predictors capable of predicting the half-life of the pMHC-I complex. These predictors were shown to predict T-cell epitopes and MHC ligands from SYFPEITHI and IEDB to form significantly more stable MHC-I complexes compared with affinity-matched non-epitopes. Combining the stability predictions with a state-of-the-art affinity predictions NetMHCcons significantly improved the performance for identification of T-cell epitopes and ligands. For the HLA alleles included in the study, we could identify distinct sub-motifs that differentiate between stable and unstable peptide binders and demonstrate that anchor positions in the N-terminal of the binding motif (primarily P2 and P3) play a critical role for the formation of stable pMHC-I complexes. A webserver implementing the method is available at www.cbs.dtu.dk/services/NetMHCstab. PMID:23927693

  10. 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

  11. DCs Pulsed with Novel HLA-A2-Restricted CTL Epitopes against Hepatitis C Virus Induced a Broadly Reactive Anti-HCV-Specific T Lymphocyte Response

    PubMed Central

    Guo, Zhongsheng; Zhang, Henghui; Rao, Huiying; Jiang, Dong; Cong, Xu; Feng, Bo; Wang, Jianghua; Wei, Lai; Chen, Hongsong

    2012-01-01

    Objective To determine the capacity of dendritic cells (DCs) loaded with single or multiple-peptide mixtures of novel hepatitis C virus (HCV) epitopes to stimulate HCV-specific cytotoxic T lymphocyte (CTL) effector functions. Methods A bioinformatics approach was used to predict HLA-A2-restricted HCV-specific CTL epitopes, and the predicted peptides identified from this screen were synthesized. Subsequent IFN-γ ELISPOT analysis detected the stimulating function of these peptides in peripheral blood mononuclear cells (PBMCs) from both chronic and self-limited HCV infected subjects (subjects exhibiting spontaneous HCV clearance). Mature DCs, derived in vitro from CD14+ monocytes harvested from the study subjects by incubation with appropriate cytokine cocktails, were loaded with novel peptide or epitope peptide mixtures and co-cultured with autologous T lymphocytes. Granzyme B (GrB) and IFN-γ ELISPOT analysis was used to test for epitope-specific CTL responses. T-cell-derived cytokines contained in the co-cultured supernatant were detected by flow cytometry. Results We identified 7 novel HLA-A2-restricted HCV-specific CTL epitopes that increased the frequency of IFN-γ-producing T cells compared to other epitopes, as assayed by measuring spot forming cells (SFCs). Two epitopes had the strongest stimulating capability in the self-limited subjects, one found in the E2 and one in the NS2 region of HCV; five epitopes had a strong stimulating capacity in both chronic and self-limited HCV infection, but were stronger in the self-limited subjects. They were distributed in E2, NS2, NS3, NS4, and NS5 regions of HCV, respectively. We also found that mDCs loaded with novel peptide mixtures could significantly increase GrB and IFN-γ SFCs as compared to single peptides, especially in chronic HCV infection subjects. Additionally, we found that DCs pulsed with multiple epitope peptide mixtures induced a Th1-biased immune response. Conclusions Seven novel and strongly stimulating

  12. 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

  13. 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

  14. Lassa fever virus peptides predicted by computational analysis induce epitope-specific cytotoxic-T-lymphocyte responses in HLA-A2.1 transgenic mice.

    PubMed

    Boesen, Agnieszka; Sundar, Krishnan; Coico, Richard

    2005-10-01

    Lassa fever is a hemorrhagic disease caused by Lassa fever virus (LV). Although the precise host defense mechanism(s) that affords protection against LV is not completely understood, cellular immunity mediated by cytotoxic T lymphocytes (CTLs) plays a pivotal role in controlling viral replication and LV infection. To date, there have been no reports mapping major histocompatibility complex (MHC) class I-binding CTL epitopes for LV. Using computer-assisted algorithms, we identified five HLA-A2.1-binding peptides of LV glycoprotein (GP) and two peptides from LV nucleoprotein (NP). Synthesized peptides were examined for their ability to bind to MHC class I molecules using a flow cytometric assay that measures peptide stabilization of class I. Three of the LV-GP peptides tested (LLGTFTWTL, SLYKGVYEL, and YLISIFLHL) stabilized HLA-A2. The LV-NP peptides tested failed to stabilize this HLA-A2. We then investigated the ability of the HLA-A2-binding LV-GP peptides to generate peptide-specific CTLs in HLA-A2.1 transgenic mice. Functional assays used to confirm CTL activation included gamma interferon enzyme-linked immunospot (ELISPOT) assays and intracellular cytokine staining of CD8+ T cells from peptide-primed mice. CTL assays were also performed to verify the cytolytic activity of peptide-pulsed target cells. Each of the LV-GP peptides induced CTL responses in HLA-A2-transgenic mice. MHC class I tetramers prepared using one LV-GP peptide that showed the highest cytolytic index (LLGTFTWTL) confirmed that peptide-binding CD8+ T cells were present in pooled lymphocytes harvested from peptide-primed mice. These findings provide direct evidence for the existence of LV-derived GP epitopes that may be useful in the development of protective immunogens for this hemorrhagic virus. PMID:16210487

  15. Lassa Fever Virus Peptides Predicted by Computational Analysis Induce Epitope-Specific Cytotoxic-T-Lymphocyte Responses in HLA-A2.1 Transgenic Mice

    PubMed Central

    Boesen, Agnieszka; Sundar, Krishnan; Coico, Richard

    2005-01-01

    Lassa fever is a hemorrhagic disease caused by Lassa fever virus (LV). Although the precise host defense mechanism(s) that affords protection against LV is not completely understood, cellular immunity mediated by cytotoxic T lymphocytes (CTLs) plays a pivotal role in controlling viral replication and LV infection. To date, there have been no reports mapping major histocompatibility complex (MHC) class I-binding CTL epitopes for LV. Using computer-assisted algorithms, we identified five HLA-A2.1-binding peptides of LV glycoprotein (GP) and two peptides from LV nucleoprotein (NP). Synthesized peptides were examined for their ability to bind to MHC class I molecules using a flow cytometric assay that measures peptide stabilization of class I. Three of the LV-GP peptides tested (LLGTFTWTL, SLYKGVYEL, and YLISIFLHL) stabilized HLA-A2. The LV-NP peptides tested failed to stabilize this HLA-A2. We then investigated the ability of the HLA-A2-binding LV-GP peptides to generate peptide-specific CTLs in HLA-A2.1 transgenic mice. Functional assays used to confirm CTL activation included gamma interferon enzyme-linked immunospot (ELISPOT) assays and intracellular cytokine staining of CD8+ T cells from peptide-primed mice. CTL assays were also performed to verify the cytolytic activity of peptide-pulsed target cells. Each of the LV-GP peptides induced CTL responses in HLA-A2-transgenic mice. MHC class I tetramers prepared using one LV-GP peptide that showed the highest cytolytic index (LLGTFTWTL) confirmed that peptide-binding CD8+ T cells were present in pooled lymphocytes harvested from peptide-primed mice. These findings provide direct evidence for the existence of LV-derived GP epitopes that may be useful in the development of protective immunogens for this hemorrhagic virus. PMID:16210487

  16. Immunogenicity of Recombinant Classic Swine Fever Virus CD8+ T Lymphocyte Epitope and Porcine Parvovirus VP2 Antigen Coexpressed by Lactobacillus casei in Swine via Oral Vaccination ▿

    PubMed Central

    Xu, Yigang; Cui, Lichun; Tian, Changyong; Zhang, Guocai; Huo, Guicheng; Tang, Lijie; Li, Yijing

    2011-01-01

    Classical swine fever virus (CSFV) and porcine parvovirus (PPV) are highly contagious pathogens, resulting in enormous economic losses in pig industries worldwide. Because vaccines play an important role in disease control, researchers are seeking improved vaccines that could induce antiviral immune responses against CSFV and PPV at the mucosal and systemic levels simultaneously. In this study, a genetically engineered Lactobacillus strain coexpressing the CSFV-specific cytotoxic T lymphocyte (CTL) epitope 290 and the VP2 antigen of PPV was developed, and its immunopotentiating capacity as an oral vaccine in pigs was analyzed. The data demonstrated that in the absence of any adjuvant, the recombinant Lactobacillus strain can efficiently stimulate mucosal and systemic CSFV-specific CD8+ CTL responses to protect pigs against CSFV challenge. Moreover, anti-PPV-VP2 serum IgG and mucosal IgA were induced in pigs immunized orally with the recombinant Lactobacillus strain, showing a neutralizing effect on PPV infection. The results suggest that the recombinant Lactobacillus microecological agent may be a valuable component of a strategy for development of a vaccine against CSFV and PPV. PMID:21940406

  17. Immunogenicity of recombinant classic swine fever virus CD8(+) T lymphocyte epitope and porcine parvovirus VP2 antigen coexpressed by Lactobacillus casei in swine via oral vaccination.

    PubMed

    Xu, Yigang; Cui, Lichun; Tian, Changyong; Zhang, Guocai; Huo, Guicheng; Tang, Lijie; Li, Yijing

    2011-11-01

    Classical swine fever virus (CSFV) and porcine parvovirus (PPV) are highly contagious pathogens, resulting in enormous economic losses in pig industries worldwide. Because vaccines play an important role in disease control, researchers are seeking improved vaccines that could induce antiviral immune responses against CSFV and PPV at the mucosal and systemic levels simultaneously. In this study, a genetically engineered Lactobacillus strain coexpressing the CSFV-specific cytotoxic T lymphocyte (CTL) epitope 290 and the VP2 antigen of PPV was developed, and its immunopotentiating capacity as an oral vaccine in pigs was analyzed. The data demonstrated that in the absence of any adjuvant, the recombinant Lactobacillus strain can efficiently stimulate mucosal and systemic CSFV-specific CD8(+) CTL responses to protect pigs against CSFV challenge. Moreover, anti-PPV-VP2 serum IgG and mucosal IgA were induced in pigs immunized orally with the recombinant Lactobacillus strain, showing a neutralizing effect on PPV infection. The results suggest that the recombinant Lactobacillus microecological agent may be a valuable component of a strategy for development of a vaccine against CSFV and PPV. PMID:21940406

  18. Three Immunoproteasome-Associated Subunits Cooperatively Generate a Cytotoxic T-Lymphocyte Epitope of Epstein-Barr Virus LMP2A by Overcoming Specific Structures Resistant to Epitope Liberation

    PubMed Central

    Ito, Yoshinori; Kondo, Eisei; Demachi-Okamura, Ayako; Akatsuka, Yoshiki; Tsujimura, Kunio; Tanimoto, Mitsune; Morishima, Yasuo; Takahashi, Toshitada; Kuzushima, Kiyotaka

    2006-01-01

    The precise roles of gamma interferon-inducible immunoproteasome-associated molecules in generation of cytotoxic T-lymphocyte (CTL) epitopes have yet to be fully elucidated. We describe here a unique epitope derived from the Epstein-Barr virus (EBV) latent membrane protein 2A (LMP2A) presented by HLA-A*2402 molecules. Generation of the epitope, designated LMP2A222-230, from the full-length protein requires the immunoproteasome subunit low-molecular-weight protein 7 (ip-LMP7) and the proteasome activator 28-α subunit and is accelerated by ip-LMP2, as revealed by gene expression experiments using an LMP2A222-230-specific CTL clone as a responder in enzyme-linked immunospot assays. The unequivocal involvement of all three components was confirmed by RNA interference gene silencing. Interestingly, the LMP2A222-230 epitope could be efficiently generated from incomplete EBV-LMP2A fragments that were produced by puromycin treatment or gene-engineered shortened EBV-LMP2A lacking some of its hydrophobic domains. In addition, epitope generation was increased by a single amino acid substitution from leucine to alanine immediately flanking the C terminus, this being predicted by a web-accessible program to increase the cleavage strength. Taken together, the data indicate that the generation of LMP2A222-230 is influenced not only by extrinsic factors such as immunoproteasomes but also by intrinsic factors such as the length of the EBV-LMP2A protein and proteasomal cleavage strength at specific positions in the source antigen. PMID:16378990

  19. Immunization with a single major histocompatibility complex class I-restricted cytotoxic T-lymphocyte recognition epitope of herpes simplex virus type 2 confers protective immunity.

    PubMed

    Blaney, J E; Nobusawa, E; Brehm, M A; Bonneau, R H; Mylin, L M; Fu, T M; Kawaoka, Y; Tevethia, S S

    1998-12-01

    We have evaluated the potential of conferring protective immunity to herpes simplex virus type 2 (HSV-2) by selectively inducing an HSV-specific CD8(+) cytotoxic T-lymphocyte (CTL) response directed against a single major histocompatibility complex class I-restricted CTL recognition epitope. We generated a recombinant vaccinia virus (rVV-ES-gB498-505) which expresses the H-2Kb-restricted, HSV-1/2-cross-reactive CTL recognition epitope, HSV glycoprotein B residues 498 to 505 (SSIEFARL) (gB498-505), fused to the adenovirus type 5 E3/19K endoplasmic reticulum insertion sequence (ES). Mucosal immunization of C57BL/6 mice with this recombinant vaccinia virus induced both a primary CTL response in the draining lymph nodes and a splenic memory CTL response directed against HSV gB498-505. To determine the ability of the gB498-505-specific memory CTL response to provide protection from HSV infection, immunized mice were challenged with a lethal dose of HSV-2 strain 186 by the intranasal (i.n.) route. Development of the gB498-505-specific CTL response conferred resistance in 60 to 75% of mice challenged with a lethal dose of HSV-2 and significantly reduced the levels of infectious virus in the brains and trigeminal ganglia of challenged mice. Finally, i.n. immunization of C57BL/6 mice with either a recombinant influenza virus or a recombinant vaccinia virus expressing HSV gB498-505 without the ES was also demonstrated to induce an HSV-specific CTL response and provide protection from HSV infection. This finding confirms that the induction of an HSV-specific CTL response directed against a single epitope is sufficient for conferring protective immunity to HSV. Our findings support the role of CD8(+) T cells in the control of HSV infection of the central nervous system and suggest the potential importance of eliciting HSV-specific mucosal CD8(+) CTL in HSV vaccine design. PMID:9811690

  20. 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

  1. 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

  2. A mutation in the HLA-B*2705-restricted NP383-391 epitope affects the human influenza A virus-specific cytotoxic T-lymphocyte response in vitro.

    PubMed

    Berkhoff, E G M; Boon, A C M; Nieuwkoop, N J; Fouchier, R A M; Sintnicolaas, K; Osterhaus, A D M E; Rimmelzwaan, G F

    2004-05-01

    Viruses can exploit a variety of strategies to evade immune surveillance by cytotoxic T lymphocytes (CTL), including the acquisition of mutations in or adjacent to CTL epitopes. Recently, an amino acid substitution (R384G) in an HLA-B*2705-restricted CTL epitope in the influenza A virus nucleoprotein (nucleoprotein containing residues 383 to 391 [NP(383-391)]; SRYWAIRTR, where R is the residue that was mutated) was associated with escape from CTL-mediated immunity. The effect of this mutation on the in vitro influenza A virus-specific CTL response was studied. To this end, two influenza A viruses, one with and one without the NP(383-391) epitope, were constructed by reverse genetics and designated influenza viruses A/NL/94-384R and A/NL/94-384G, respectively. The absence of the HLA-B*2705-restricted CTL epitope in influenza virus A/NL/94-384G was confirmed by using (51)Cr release assays with a T-cell clone specific for the NP(383-391) epitope. In addition, peripheral blood mononuclear cells (PBMC) stimulated with influenza virus A/NL/94-384G failed to recognize HLA-B*2705-positive target cells pulsed with the original NP(383-391) peptide. The proportion of virus-specific CD8+ gamma interferon (IFN-gamma)-positive T cells in in vitro-stimulated PBMC was determined by intracellular IFN-gamma staining after restimulation with virus-infected autologous B-lymphoblastoid cell lines and C1R cell lines expressing only HLA-B*2705. The proportion of virus-specific CD8+ T cells was lower in PBMC stimulated in vitro with influenza virus A/NL/94-384G obtained from several HLA-B*2705-positive donors than in PBMC stimulated with influenza virus A/NL/94-384R. This finding indicated that amino acid variations in CTL epitopes can affect the virus-specific CTL response and that the NP(383-391) epitope is the most important HLA-B*2705-restricted epitope in the nucleoprotein of influenza A viruses. PMID:15113903

  3. Myelin basic protein-specific T lymphocyte repertoire in multiple sclerosis. Complexity of the response and dominance of nested epitopes due to recruitment of multiple T cell clones.

    PubMed Central

    Meinl, E; Weber, F; Drexler, K; Morelle, C; Ott, M; Saruhan-Direskeneli, G; Goebels, N; Ertl, B; Jechart, G; Giegerich, G

    1993-01-01

    The human T cell response to the myelin basic protein (MBP) has been studied with respect to T cell receptor (TCR) usage, HLA class II restriction elements, and epitope specificity using a total of 215 long-term MBP-specific T cell lines (TCL) isolated from the peripheral blood of 13 patients with multiple sclerosis (MS) and 10 healthy donors. In most donors, the anti-MBP response was exceedingly heterogeneous. Using a panel of overlapping synthetic peptides spanning the entire length of human MBP, at least 26 epitopes recognized by human TCL could be distinguished. The MBP domain most commonly recognized was sequence 80-105 (31% of MS TCL, and 24% of control TCL). Sequence 29-48 was recognized more frequently by control-derived TCL (24%) than by TCL from MS patients (5%). The MBP epitopes were recognized in the context of DRB1 *0101, DRB5*0101, DRB1*1501, DRB1*0301, DRB1*0401, DRB1*1402, and DRB3*0102, as demonstrated using a panel of DR gene-transfected L cells. The TCR gene usage was also heterogeneous. V beta 5.2, a peptide of which is currently being used in a clinical trial for treatment of MS patients, was expressed by only one of our TCL. However, within this complex pattern of MBP-specific T cell responses, a minority of MS patients were found to exhibit a more restricted response with respect to their TCL epitope specificity. In these patients 75-87% of the TCL responded to a single, patient-specific cluster of immunodominant T cell epitopes located within a small (20-amino acid) domain of MBP. These nested clusters of immunodominant epitopes were noted within the amino acids 80-105, 108-131, and 131-153. The T cell response to the immunodominant epitopes was not monoclonal, but heterogeneous, with respect to fine specificity, TCR usage, and even HLA restriction. In one patient (H.K.), this restricted epitope profile remained stable for > 2 yr. The TCR beta chain sequences of TCL specific for the immunodominant region of HK are consistent with an

  4. Escape in One of Two Cytotoxic T-Lymphocyte Epitopes Bound by a High-Frequency Major Histocompatibility Complex Class I Molecule, Mamu-A*02: a Paradigm for Virus Evolution and Persistence?

    PubMed Central

    Vogel, Thorsten U.; Friedrich, Thomas C.; O'Connor, David H.; Rehrauer, William; Dodds, Elizabeth J.; Hickman, Heather; Hildebrand, William; Sidney, John; Sette, Alessandro; Hughes, Austin; Horton, Helen; Vielhuber, Kathy; Rudersdorf, Richard; de Souza, Ivna P.; Reynolds, Matthew R.; Allen, Todd M.; Wilson, Nancy; Watkins, David I.

    2002-01-01

    It is now accepted that an effective vaccine against AIDS must include effective cytotoxic-T-lymphocyte (CTL) responses. The simian immunodeficiency virus (SIV)-infected rhesus macaque is the best available animal model for AIDS, but analysis of macaque CTL responses has hitherto focused mainly on epitopes bound by a single major histocompatibility complex (MHC) class I molecule, Mamu-A*01. The availability of Mamu-A*01-positive macaques for vaccine studies is therefore severely limited. Furthermore, it is becoming clear that different CTL responses are able to control immunodeficiency virus replication with varying success, making it a priority to identify and analyze CTL responses restricted by common MHC class I molecules other than Mamu-A*01. Here we describe two novel epitopes derived from SIV, one from Gag (Gag71-79 GY9), and one from the Nef protein (Nef159-167 YY9). Both epitopes are bound by the common macaque MHC class I molecule, Mamu-A*02. The sequences of these two eptiopes are consistent with the molecule's peptide-binding motif, which we have defined by elution of natural ligands from Mamu-A*02. Strikingly, we found evidence for the selection of escape variant viruses by CTL specific for Nef159-167 YY9 in 6 of 6 Mamu-A*02-positive animals. In contrast, viral sequences encoding the Gag71-79 GY9 epitope remained intact in each animal. This situation is reminiscent of Mamu-A*01-restricted CTL that recognize Tat28-35 SL8, which reproducibly selects for escape variants during acute infection, and Gag181-189 CM9, which does not. Differential selection by CTL may therefore be a paradigm of immunodeficiency virus infection. PMID:12388723

  5. CD8+ T Lymphocyte Epitopes From The Herpes Simplex Virus Type 2 ICP27, VP22 and VP13/14 Proteins To Facilitate Vaccine Design And Characterization.

    PubMed

    Platt, Rebecca J; Khodai, Tansi; Townend, Tim J; Bright, Helen H; Cockle, Paul; Perez-Tosar, Luis; Webster, Rob; Champion, Brian; Hickling, Timothy P; Mirza, Fareed

    2013-01-01

    CD8+ T cells have the potential to control HSV-2 infection. However, limited information has been available on CD8+ T cell epitopes or the functionality of antigen specific T cells during infection or following immunization with experimental vaccines. Peptide panels from HSV-2 proteins ICP27, VP22 and VP13/14 were selected from in silico predictions of binding to human HLA-A*0201 and mouse H-2Kd, Ld and Dd molecules. Nine previously uncharacterized CD8+ T cell epitopes were identified from HSV-2 infected BALB/c mice. HSV-2 specific peptide sequences stabilized HLA-A*02 surface expression with intermediate or high affinity binding. Peptide specific CD8+ human T cell lines from peripheral blood lymphocytes were generated from a HLA-A*02+ donor. High frequencies of peptide specific CD8+ T cell responses were elicited in mice by DNA vaccination with ICP27, VP22 and VP13/14, as demonstrated by CD107a mobilization. Vaccine driven T cell responses displayed a more focused immune response than those induced by viral infection. Furthermore, vaccination with ICP27 reduced viral shedding and reduced the clinical impact of disease. In conclusion, this study describes novel HSV-2 epitopes eliciting strong CD8+ T cell responses that may facilitate epitope based vaccine design and aid immunomonitoring of antigen specific T cell frequencies in preclinical and clinical settings. PMID:24709642

  6. Multispecific and heterogeneous recognition of the gag protein by cytotoxic T lymphocytes (CTL) from HIV-infected patients: factors other than the MHC control the epitopic specificities.

    PubMed Central

    Buseyne, F; Janvier, G; Fleury, B; Schmidt, D; Rivière, Y

    1994-01-01

    The HIV gag polyprotein is a major target for recognition by CTL in infected humans. Using recombinant vaccinia viruses (rVV) expressing truncations of the p24gag, and the p18gag, p15gag and HIV-2 p56gag proteins, the characterization of epitope regions recognized by in vitro-stimulated peripheral blood mononuclear cells (PBMC) from 18 infected patients has been studied. The gag-specific response of most individuals is polyclonal and multispecific, and interindividual variations between target epitope regions were frequently observed, despite shared MHC alleles. As CTL may play an important role in the control of HIV replication in infected hosts, these results have important implications for designing vaccine strategies. PMID:7521806

  7. Simultaneous assessment of cytotoxic T lymphocyte responses against multiple viral infections by combined usage of optimal epitope matrices, anti- CD3 mAb T-cell expansion and "RecycleSpot"

    PubMed Central

    Bihl, Florian K; Loggi, Elisabetta; Chisholm, John V; Hewitt, Hannah S; Henry, Leah M; Linde, Caitlyn; Suscovich, Todd J; Wong, Johnson T; Frahm, Nicole; Andreone, Pietro; Brander, Christian

    2005-01-01

    The assessment of cellular anti-viral immunity is often hampered by the limited availability of adequate samples, especially when attempting simultaneous, high-resolution determination of T cell responses against multiple viral infections. Thus, the development of assay systems, which optimize cell usage, while still allowing for the detailed determination of breadth and magnitude of virus-specific cytotoxic T lymphocyte (CTL) responses, is urgently needed. This study provides an up-to-date listing of currently known, well-defined viral CTL epitopes for HIV, EBV, CMV, HCV and HBV and describes an approach that overcomes some of the above limitations through the use of peptide matrices of optimally defined viral CTL epitopes in combination with anti-CD3 in vitro T cell expansion and re-use of cells from negative ELISpot wells. The data show that, when compared to direct ex vivo cell preparations, antigen-unspecific in vitro T cell expansion maintains the breadth of detectable T cell responses and demonstrates that harvesting cells from negative ELISpot wells for re-use in subsequent ELISpot assays (RecycleSpot), further maximized the use of available cells. Furthermore when combining T cell expansion and RecycleSpot with the use of rationally designed peptide matrices, antiviral immunity against more than 400 different CTL epitopes from five different viruses can be reproducibly assessed from samples of less than 10 milliliters of blood without compromising information on the breadth and magnitude of these responses. Together, these data support an approach that facilitates the assessment of cellular immunity against multiple viral co-infections in settings where sample availability is severely limited. PMID:15888204

  8. Incomplete Cd8+ T Lymphocyte Differentiation as a Mechanism for Subdominant Cytotoxic T Lymphocyte Responses to a Viral Antigen

    PubMed Central

    Spencer, Juliet V.; Braciale, Thomas J.

    2000-01-01

    CD8+ cytotoxic T lymphocytes (CTLs) recognize antigen in the context of major histocompatibility complex (MHC) class I molecules. Class I epitopes have been classified as dominant or subdominant depending on the magnitude of the CTL response to the epitope. In this report, we have examined the in vitro memory CTL response of H-2d haplotype murine CD8+ T lymphocytes specific for a dominant and subdominant epitope of influenza hemagglutinin using activation marker expression and staining with soluble tetrameric MHC–peptide complexes. Immune CD8+ T lymphocytes specific for the dominant HA204-210 epitope give rise to CTL effectors that display activation markers, stain with the HA204 tetramer, and exhibit effector functions (i.e., cytolytic activity and cytokine synthesis). In contrast, stimulation of memory CD8+ T lymphocytes directed to the subdominant HA210-219 epitope results in the generation of a large population of activated CD8+ T cells that exhibit weak cytolytic activity and fail to stain with the HA210 tetramer. After additional rounds of restimulation with antigen, the HA210-219–specific subdominant CD8+ T lymphocytes give rise to daughter cells that acquire antigen-specific CTL effector activity and transition from a HA210 tetramer–negative to a tetramer-positive phenotype. These results suggest a novel mechanism to account for weak CD8+ CTL responses to subdominant epitopes at the level of CD8+ T lymphocyte differentiation into effector CTL. The implications of these findings for CD8+ T lymphocyte activation are discussed. PMID:10811862

  9. IMMUNODOMINANT EPITOPES IN BABESIA BOVIS RHOPTRY ASSOCIATED PROTEIN-1 THAT ELICIT MEMORY CD4+-T-LYMPHOCYTE RESPONSES IN B. BOVIS IMMUNE INDIVIDUALS ARE LOCATED IN THE AMINO-TERMINAL DOMAIN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Babesia bovis rhoptry-associated protein 1 (RAP-1), which confers partial protection against B. bovis challenge, is recognized by antibodies and T lymphocytes from cattle that have recovered from infection and are immune to subsequent challenge. RAP-1 is a 60-kDa protein with an N-terminal (NT) regi...

  10. 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

  11. Identification of cytotoxic T cell epitopes within Epstein-Barr virus (EBV) oncogene latent membrane protein 1 (LMP1): evidence for HLA A2 supertype-restricted immune recognition of EBV-infected cells by LMP1-specific cytotoxic T lymphocytes.

    PubMed

    Khanna, R; Burrows, S R; Nicholls, J; Poulsen, L M

    1998-02-01

    Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) and latent membrane proteins (LMP) are the only antigens consistently expressed in malignancies such as nasopharyngeal carcinoma (NPC) and Hodgkin's disease (HD). Since EBNA1 is not recognized by EBV-specific cytotoxic T lymphocytes (CTL), there is increasing interest in the identification of the potential target epitopes within LMP1. Although LMP1-specific CTL have been isolated from seropositive individuals, earlier attempts to identify the peptide epitopes recognized by these T cells have been unsuccessful. In the present report we used a novel protocol to identify CTL epitopes within LMP1 which can be recognized by both polyclonal and clonal CTL. Firstly, a computer-based program was employed to identify the potential HLA-binding peptides within LMP1. Polyclonal CD8+ CTL were then isolated from seropositive donors that recognized the peptide epitopes YLLEMLWRL and YLQQNWWTL from LMP1 in association with HLA A2. Limiting dilution analysis of the memory CTL response revealed that the LMP1-specific CTL response constitutes a minor component of the CTL response in healthy virus carriers. Interestingly, analysis of YLLEMLWRL-specific CTL revealed that these CTL were able to lyse EBV-infected B cells expressing different HLA A2 supertype alleles including A*0201, A*0202, A*0203, A*0204, A*0206, A*6802 and A*6901. These data strongly support the notion that HLA class I supertype-restricted CTL may be of significant use in the development of peptide-based immunotherapeutics against EBV-associated malignancies in different ethnic populations. PMID:9521052

  12. 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

  13. 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

  14. Macroautophagy in T Lymphocyte Development and Function

    PubMed Central

    He, Ming-Xiao; McLeod, Ian X.; Jia, Wei; He, You-Wen

    2011-01-01

    Macroautophagy (referred to as autophagy) is a fundamental intracellular process characterized by the sequestration of cytoplasmic compartments through double-membrane vesicles, termed autophagosomes. Recent studies have established important roles of autophagy in regulating T lymphocyte development and function. Resting T lymphocytes have basal levels of autophagy that is upregulated by T cell receptor stimulation. Several specific knockout or transgenic models have been developed during the past few years, and it has been revealed that autophagy plays an essential role in regulating thymocyte selection, peripheral T cell survival, and proliferation. The regulation of T cell development and function by autophagy is mediated through its role in regulating self-antigen presentation, intracellular organelle homeostasis, and energy production. Here we will review the current findings concerning how autophagy regulates T cell function, as well as compare different models in studying autophagy in T lymphocytes. PMID:22566906

  15. Shigella impairs T lymphocyte dynamics in vivo

    PubMed Central

    Salgado-Pabón, Wilmara; Celli, Susanna; Arena, Ellen T.; Nothelfer, Katharina; Roux, Pascal; Sellge, Gernot; Frigimelica, Elisabetta; Bousso, Philippe; Sansonetti, Philippe J.; Phalipon, Armelle

    2013-01-01

    The Gram-negative enteroinvasive bacterium Shigella flexneri is responsible for the endemic form of bacillary dysentery, an acute rectocolitis in humans. S. flexneri uses a type III secretion system to inject effector proteins into host cells, thus diverting cellular functions to its own benefit. Protective immunity to reinfection requires several rounds of infection to be elicited and is short-lasting, suggesting that S. flexneri interferes with the priming of specific immunity. Considering the key role played by T-lymphocyte trafficking in priming of adaptive immunity, we investigated the impact of S. flexneri on T-cell dynamics in vivo. By using two-photon microscopy to visualize bacterium–T-cell cross-talks in the lymph nodes, where the adaptive immunity is initiated, we provide evidence that S. flexneri, via its type III secretion system, impairs the migration pattern of CD4+ T cells independently of cognate recognition of bacterial antigens. We show that bacterial invasion of CD4+ T lymphocytes occurs in vivo, and results in cell migration arrest. In the absence of invasion, CD4+ T-cell migration parameters are also dramatically altered. Signals resulting from S. flexneri interactions with subcapsular sinus macrophages and dendritic cells, and recruitment of polymorphonuclear cells are likely to contribute to this phenomenon. These findings indicate that S. flexneri targets T lymphocytes in vivo and highlight the role of type III effector secretion in modulating host adaptive immune responses. PMID:23417297

  16. Differentiation and activation phenotypes of lung T lymphocytes differ from those of circulating T lymphocytes.

    PubMed Central

    Davidson, B L; Faust, J; Pessano, S; Daniele, R P; Rovera, G

    1985-01-01

    We used dual laser two-color flow cytometry to compare the expression of surface markers associated with activation and with differentiation in lung and peripheral blood T lymphocytes from normal subjects. T cell subsets, defined based on their reactivity with monoclonal antibodies (MAb) OKT3, OKT4, and OKT8, were analyzed for expression of activation antigens as detected by MAbs to the interleukin-2 receptor, the transferrin receptor, and HLA-DR determinants. Whereas circulating T lymphocytes expressed the three activation antigens at low levels, and the total of T4+ and T8+ cells always approximated the number of T3+ cells, lung T lymphocytes of the T3+, T4+, and T8+ populations expressed the activation antigens at variable levels in combinations not seen in circulating lymphocytes, and the sum of T4+ and T8+ cells always exceeded the T3+ total. A proportion of T4+T8+ cells was detected in lung lymphocytes. PMID:3926821

  17. Thymic influence on the T-lymphocyte self MHC repertoire. II. Cytotoxic T-lymphocyte precursors.

    PubMed

    Jenski, L J; Miller, B A

    1988-01-01

    We measured the frequency and specificity of thymic alloantigen-reactive cytotoxic T-lymphocyte precursors in spleens of allogeneic thymus-grafted nude mice tolerant to thymic alloantigens. Under our conditions of limiting dilution analysis we found no selective loss of cytotoxic T-lymphocyte precursors in allogeneic thymus-grafted mice. Upon analysis of individual cytotoxic T-lymphocyte clones, we found that lysis of specific and third party targets was mediated by distinct clones specific for H-2 antigens. Precursors from allogeneic thymus-grafted nudes stimulated at limiting dilutions with thymic alloantigens tended to lyse fewer targets than were lysed by normal cytotoxic T-lymphocytes or allogeneic thymus-grafted nude precursors stimulated with third party alloantigens, but the reduction in lytic activity was not statistically significant. Specific suppression was not demonstrated, but could not be ruled out unequivocally. We conclude that intrathymic deletion of thymic alloantigen-reactive pCTL is not necessary to achieve specific tolerance to thymic alloantigens. PMID:3259029

  18. Identification of Vaccine Candidate Peptides in the NcSRS2 Surface Protein of Neospora caninum by Using CD4+ Cytotoxic T Lymphocytes and Gamma Interferon-Secreting T Lymphocytes of Infected Holstein Cattle

    PubMed Central

    Staska, Lauren M.; Davies, Christopher J.; Brown, Wendy C.; McGuire, Travis C.; Suarez, Carlos E.; Park, Joo Youn; Mathison, Bruce A.; Abbott, Jeffrey R.; Baszler, Timothy V.

    2005-01-01

    Previously, our laboratory showed that Holstein cattle experimentally infected with Neospora caninum develop parasite-specific CD4+ cytotoxic T lymphocytes (CTL) that lyse infected, autologous target cells through a perforin-granzyme pathway. To identify specific parasite antigens inducing bovine CTL and helper T-lymphocyte responses for vaccine development against bovine neosporosis, the tachyzoite major surface proteins NcSAG1 and NcSRS2 were targeted. In whole tachyzoite antigen-expanded bovine T-lymphocyte lines, recombinant NcSRS2 induced potent memory CD4+- and CD8+-T-lymphocyte activation, as indicated by proliferation and gamma interferon (IFN-γ) secretion, while recombinant NcSAG1 induced a minimal memory response. Subsequently, T-lymphocyte epitope-bearing peptides of NcSRS2 were mapped by using overlapping peptides covering the entire NcSRS2 sequence. Four experimentally infected cattle with six different major histocompatibility complex (MHC) class II haplotypes were the source of immune cells used to identify NcSRS2 peptides presented by Holstein MHC haplotypes. NcSRS2 peptides were mapped by using IFN-γ secretion by rNcSRS2-stimulated, short-term T-lymphocyte cell lines, IFN-γ enzyme-linked immunospot (ELISPOT) assay with peripheral blood mononuclear cells, and 51Cr release cytotoxicity assay of rNcSRS2-stimulated effector cells. Four N. caninum-infected Holstein cattle developed NcSRS2 peptide-specific T lymphocytes detected ex vivo in peripheral blood by IFN-γ ELISPOT and in vitro by measuring T-lymphocyte IFN-γ production and cytotoxicity. An immunodominant region of NcSRS2 spanning amino acids 133 to 155 was recognized by CD4+ T lymphocytes from the four cattle. These findings support investigation of subunit N. caninum vaccines incorporating NcSRS2 gene sequences or peptides for induction of NcSRS2 peptide-specific CTL and IFN-γ-secreting T lymphocytes in cattle with varied MHC genotypes. PMID:15731029

  19. [T-LYMPHOCYTES AND TISSUE GROWTH FACTORS].

    PubMed

    Tishevskaya, N V; Gevorkyan, N M; Kozlova, N I

    2015-08-01

    Lympnoici regulation, in aciaition to ensuring tne protection of tne antigen, is aimecl at maintaining a qualitative, quantitative, structural and functional integrity of the body. T-lymphocytes and growth factors are involved in cell proliferation, differentiation, and tissue and organ regeneration. Lymphocyte's, sensitivity to homeostasis changes and their morphogenetic function are connected with a large number of receptors to bioactive substances and with their ability to syn- thesize and secrete hormones and tissue growth factors. At the same time tissue growth factors are involved in the development of thymocytes, in the differentiation of T helper and cytotoxic lymphocytes. Growth factors modulate the functions of Thl, Th2, Treg, Thl7, Th9. The important aspects of the interaction of T cells and EGF, TGF-P, FGF, VEGF, PlGF, HGF/SF in normal and pathological conditions are shown in this review. PMID:26591583

  20. Physiological implications of NTBI uptake by T lymphocytes

    PubMed Central

    Pinto, Jorge P.; Arezes, João; Dias, Vera; Oliveira, Susana; Vieira, Inês; Costa, Mónica; Vos, Matthijn; Carlsson, Anna; Rikers, Yuri; Rangel, Maria; Porto, Graça

    2014-01-01

    In iron overload disorders a significant fraction of the total iron circulates in the plasma as low molecular weight complexes not bound to transferrin, known as non-transferrin-bound iron (NTBI). By catalyzing the formation of free radicals, NTBI accumulation results in oxidative stress and cellular damage, being a major cause of organ toxicity. NTBI is rapidly and preferentially cleared from circulation by the liver and the myocardium, the main disease targets in iron overload conditions. We have recently demonstrated that human peripheral blood T lymphocytes take up NTBI in vitro, with a pattern that resembles that of hepatocytes. Since T lymphocytes constitute a numerically important component of the circulating cell pool, these findings support a putative role for this cell type in the systemic protection against iron toxicity. Here we tested the hypothesis that the circulating peripheral blood T lymphocyte pool constitutes an important storage compartment for NTBI and is thus a modifier of NTBI deposition in target organs. First we show that NTBI uptake by human T lymphocytes increases the expression of the iron-storage protein ferritin and of the iron exporter ferroportin via an IRE-dependent mechanism. NTBI retention by T lymphocytes is shown to be critically controlled by the hepcidin-mediated modulation of ferroportin both in vitro and in vivo. Finally, the protective effect of T lymphocytes was tested by analyzing the patterns of iron accumulation in the T lymphocyte-deficient mouse model Foxn1nu before and after reconstitution with T lymphocytes by adoptive transfer. The results confirmed a significant increase of liver and pancreas iron accumulation in T lymphocyte-deficient mice. NTBI accumulation in the liver and spleen was prevented by reconstitution with syngeneic T lymphocytes. Altogether, our results demonstrate that T lymphocytes are important components of a circulating “NTBI storage compartment” and show its physiological relevance as a

  1. No evidence for competition between cytotoxic T-lymphocyte responses in HIV-1 infection.

    PubMed

    Fryer, Helen R; Scherer, Almut; Oxenius, Annette; Phillips, Rodney; McLean, Angela R

    2009-12-22

    Strong competition between cytotoxic T-lymphocytes (CTLs) specific for different epitopes in human immunodeficiency virus (HIV) infection would have important implications for the design of an HIV vaccine. To investigate evidence for this type of competition, we analysed CTL response data from 97 patients with chronic HIV infection who were frequently sampled for up to 96 weeks. For each sample, CTL responses directed against a range of known epitopes in gag, pol and nef were measured using an enzyme-linked immunospot assay. The Lotka-Volterra model of competition was used to predict patterns that would be expected from these data if competitive interactions materially affect CTL numbers. In this application, the model predicts that when hosts make responses to a larger number of epitopes, they would have diminished responses to each epitope and that if one epitope-specific response becomes dramatically smaller, others would increase in size to compensate; conversely if one response grows, others would shrink. Analysis of the experimental data reveals results that are wholly inconsistent with these predictions. In hosts who respond to more epitopes, the average epitope-specific response tends to be larger, not smaller. Furthermore, responses to different epitopes almost always increase in unison or decrease in unison. Our findings are therefore inconsistent with the hypothesis that there is competition between CTL responses directed against different epitopes in HIV infection. This suggests that vaccines that elicit broad responses would be favourable because they would direct a larger total response against the virus, in addition to being more robust to the effects of CTL escape. PMID:19776069

  2. Signal transduction in T lymphocytes in microgravity

    NASA Technical Reports Server (NTRS)

    Cogoli, A.

    1997-01-01

    More than 120 experiments conducted in space in the last 15 years have shown that dramatic changes are occurring in several types of single cells during their exposure to microgravity. One focus of today's research on cells in space is on signal transduction, especially those steps involving the cytoskeleton and cell-cell interactions. Signal transduction is often altered in microgravity as well as in hypergravity. This leads to changes in cell proliferation, genetic expression and differentiation. Interesting examples are leukocytes, HeLa cells, epidermoid cells and osteoblastic cells. Signalling pathways were studied in T lymphocytes in microgravity by several investigators after the discovery that mitogenic activation in vitro is virtually nil at 0g. T cells are a good model to study signal transduction because three extracellular signals (mitogen, IL-1 and IL-2) are required for full activation, and two classical pathways (via proteins G and PKC) are activated within the cell. In addition, low molecular weight GTP-binding proteins (Ras and Rap) are interacting with the cytoskeleton. The data at 0g support the notion that the expression of IL-2 receptor is inhibited at 0g, while mitogen binding and the transmission of IL-1 by accessory cells occur normally. In addition, alterations of the cytoskeleton suggest that the interaction with Rap proteins is disturbed. Data obtained with phorbol esters indicate that the function of PKC is changed in microgravity. Similar conclusions are drawn from the results with epidermoid cells A431.

  3. ACTIVATION OF T LYMPHOCYTES IN ATHEROSCLEROTIC PLAQUES

    PubMed Central

    Grivel, Jean-Charles; Ivanova, Oxana; Pinegina, Natalia; Blank, Paul S.; Shpektor, Alexander; Margolis, Leonid B.; Vasilieva, Elena

    2011-01-01

    Objective To decipher the immunological mechanisms of plaque maturation and rupture, it is necessary to analyze the phenotypes and distribution of individual lymphocytes which migrate to the plaques as well as their activation at different stages of plaque formation. Methods and Results We developed a protocol to isolate plaque-residing immune cells and analyze their status using polychromatic flow cytometry. We found that the composition and phenotype of T lymphocytes in the plaques differs from that in blood. CD4 and, in particular, CD8+ T cells in plaques are highly activated; the fraction of CD8 T cells co-expressing CD25 and HLA-DR in plaques was 10 times larger than in blood. Conclusions The first flow-cytoanalysis of individual T cells in atherosclerotic plaques indicates that plaques represent a separate immunological compartment from blood with lymphocytes characterized by a high level of T cells activation, which is compatible with the presence of antigen(s) that trigger infiltration activation of these cells. The ability to isolate and characterize these cells may lead to the identification of such antigens. PMID:21960562

  4. Peptide microarrays for the profiling of cytotoxic T-lymphocyte activity using minimum numbers of cells

    PubMed Central

    Hoff, Antje; Bagû, Ana-Cristina; André, Thomas; Roth, Günter; Wiesmüller, Karl-Heinz; Gückel, Brigitte

    2010-01-01

    The identification of epitopes that elicit cytotoxic T-lymphocyte activity is a prerequisite for the development of cancer-specific immunotherapies. However, especially the parallel characterization of several epitopes is limited by the availability of T cells. Microarrays have enabled an unprecedented miniaturization and parallelization in biological assays. Here, we developed peptide microarrays for the detection of CTL activity. MHC class I-binding peptide epitopes were pipetted onto polymer-coated glass slides. Target cells, loaded with the cell-impermeant dye calcein, were incubated on these arrays, followed by incubation with antigen-expanded CTLs. Cytotoxic activity was detected by release of calcein and detachment of target cells. With only 200,000 cells per microarray, CTLs could be detected at a frequency of 0.5% corresponding to 1,000 antigen-specific T cells. Target cells and CTLs only settled on peptide spots enabling a clear separation of individual epitopes. Even though no physical boundaries were present between the individual spots, peptide loading only occurred locally and cytolytic activity was confined to the spots carrying the specific epitope. The peptide microarrays provide a robust platform that implements the whole process from antigen presentation to the detection of CTL activity in a miniaturized format. The method surpasses all established methods in the minimum numbers of cells required. With antigen uptake occurring on the microarray, further applications are foreseen in the testing of antigen precursors that require uptake and processing prior to presentation. PMID:20512327

  5. A Dominant Role for CD8+-T-Lymphocyte Selection in Simian Immunodeficiency Virus Sequence Variation†

    PubMed Central

    O'Connor, David H.; McDermott, Adrian B.; Krebs, Kendall C.; Dodds, Elizabeth J.; Miller, Jacqueline E.; Gonzalez, Edna J.; Jacoby, Timothy J.; Yant, Levi; Piontkivska, Helen; Pantophlet, Ralph; Burton, Dennis R.; Rehrauer, William M.; Wilson, Nancy; Hughes, Austin L.; Watkins, David I.

    2004-01-01

    CD8+ T lymphocytes (CD8-TL) select viral escape variants in both human immunodeficiency virus and simian immunodeficiency virus (SIV) infections. The frequency of CD8-TL viral escape as well as the contribution of escape to overall virus diversification has not been assessed. We quantified CD8-TL selection in SIV infections by sequencing viral genomes from 35 SIVmac239-infected animals at the time of euthanasia. Here we show that positive selection for sequences encoding 46 known CD8-TL epitopes is comparable to the positive selection observed for the variable loops of env. We also found that >60% of viral variation outside of the viral envelope occurs within recognized CD8-TL epitopes. Therefore, we conclude that CD8-TL selection is the dominant cause of SIV diversification outside of the envelope. PMID:15564508

  6. 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

  7. Subsets of T lymphocytes in relation to T lymphocyte function in multiple sclerosis.

    PubMed Central

    Craig, J C; Hawkins, S A; Swallow, M W; Lyttle, J A; Patterson, V H; Merrett, J D; Haire, M

    1985-01-01

    T lymphocyte control of Epstein-Barr virus (EBV) infection of autologous B lymphocytes was examined in parallel to the enumeration of subpopulations of mononuclear cells in 22 multiple sclerosis (MS) patients and in 22 healthy individuals. All were seropositive for EBV. The incidence of lack of T cell control was significantly higher in patients than in controls, confirming previous published work. In the present study, we have shown in addition a significantly reduced proportion of OKT8+ cells and a significantly increased ratio of OKT4/OKT8 cells in the group of patients with lack of control. The findings point to abnormal immunoregulation in MS. PMID:3000660

  8. Asymmetric Cell Division in T Lymphocyte Fate Diversification.

    PubMed

    Arsenio, Janilyn; Metz, Patrick J; Chang, John T

    2015-11-01

    Immunological protection against microbial pathogens is dependent on robust generation of functionally diverse T lymphocyte subsets. Upon microbial infection, naïve CD4(+) or CD8(+) T lymphocytes can give rise to effector- and memory-fated progeny that together mediate a potent immune response. Recent advances in single-cell immunological and genomic profiling technologies have helped elucidate early and late diversification mechanisms that enable the generation of heterogeneity from single T lymphocytes. We discuss these findings here and argue that one such mechanism, asymmetric cell division, creates an early divergence in T lymphocyte fates by giving rise to daughter cells with a propensity towards the terminally differentiated effector or self-renewing memory lineages, with cell-intrinsic and -extrinsic cues from the microenvironment driving the final maturation steps. PMID:26474675

  9. Biophysical Aspects of T Lymphocyte Activation at the Immune Synapse

    PubMed Central

    Hivroz, Claire; Saitakis, Michael

    2016-01-01

    T lymphocyte activation is a pivotal step of the adaptive immune response. It requires the recognition by T-cell receptors (TCR) of peptides presented in the context of major histocompatibility complex molecules (pMHC) present at the surface of antigen-presenting cells (APCs). T lymphocyte activation also involves engagement of costimulatory receptors and adhesion molecules recognizing ligands on the APC. Integration of these different signals requires the formation of a specialized dynamic structure: the immune synapse. While the biochemical and molecular aspects of this cell–cell communication have been extensively studied, its mechanical features have only recently been addressed. Yet, the immune synapse is also the place of exchange of mechanical signals. Receptors engaged on the T lymphocyte surface are submitted to many tensile and traction forces. These forces are generated by various phenomena: membrane undulation/protrusion/retraction, cell mobility or spreading, and dynamic remodeling of the actomyosin cytoskeleton inside the T lymphocyte. Moreover, the TCR can both induce force development, following triggering, and sense and convert forces into biochemical signals, as a bona fide mechanotransducer. Other costimulatory molecules, such as LFA-1, engaged during immune synapse formation, also display these features. Moreover, T lymphocytes themselves are mechanosensitive, since substrate stiffness can modulate their response. In this review, we will summarize recent studies from a biophysical perspective to explain how mechanical cues can affect T lymphocyte activation. We will particularly discuss how forces are generated during immune synapse formation; how these forces affect various aspects of T lymphocyte biology; and what are the key features of T lymphocyte response to stiffness. PMID:26913033

  10. The Role of the T lymphocytes and Remodeling in Asthma.

    PubMed

    Amin, Kawa

    2016-08-01

    In allergic asthma (AA), inflammatory changes in the airway epithelium may contribute to the characteristic pathophysiology and symptoms. The presence of T lymphocytes, eosinophils, mast cells and macrophages, the presence of cytokines, and also structural changes in the airway mucous membrane are characteristic for asthma. Bronchial biopsy specimens were obtained from 33 AA, 25 nonallergic asthma (NAA), and 20 healthy controls (HC). This study used immunohistochemical techniques for identified monoclonal antibodies (CD3, CD4, CD8, CD25, ECP, MBP, tenascin, and laminin) in the bronchi. The highest number of eosinophils and T lymphocyte cells in bronchial biopsies was found in AA, and NAA. The number of T lymphocytes in AA was significantly higher than in NAA and HC. The degree of epithelial damage was higher in the AA group compared to the other groups. The tenascin- and laminin-positive layers in AA were thicker than other groups. In AA, a significant negative correlation was found between epithelial integrity and the count for eosinophils or T lymphocytes. T lymphocytes and eosinophils in AA were found in the area of epithelial and lamina propria damage. This article suggests that T lymphocytes may not only contribute to the chronic airway inflammatory response, airway remodeling, and symptomatology but may also have a central role at the initiation of the allergic immune response. Th-targeted therapy would be of considerable interest in controlling AA. Having more knowledge on the roles of T lymphocytes in the pathogenesis of allergic inflammation highlights the contributions of these cells in regulating and may lead to a new therapeutic target-AA. PMID:27221139

  11. Psychosocial factors and T lymphocyte counts in Brazilian peacekeepers

    PubMed Central

    Monteiro da Silva, Angela M; Speranza, Francisco A B; Ishii, Solange Kiyoko; Hirata, Raphael; Mattos-Guaraldi, Ana Luíza; Milagres, Lucimar Gonçalves

    2015-01-01

    OBJECTIVE: To investigate the associations between psychosocial factors and peripheral blood CD4 and CD8 T lymphocyte numbers in Brazilian peacekeepers. METHODS: Venous blood was collected from 759 peacekeepers who had just returned from a peace mission in Haiti. Among the 759 soldiers, 642 individuals completed the psychosocial measures. CD4 and CD8 T lymphocyte counts were measured by flow cytometry using a commercially available kit. Psychosocial factors, including military peace force stressors, clinical stress, anxiety and depression, were recorded. As a reference for T lymphocyte numbers, we measured T lymphocyte counts in 75 blood donors from the Instituto de Biologia do Exército, Rio de Janeiro. RESULTS: The median numbers of CD4 and CD8 T lymphocytes in the blood donors were 819 cells/µl and 496 cells/µl, respectively, with a CD4:CD8 ratio of 1.6. Significantly (p<0.05) lower CD4 T cell counts (759 cells/µl) were recorded for peacekeepers, with similar CD8 levels (548 cells/µl) and smaller CD4:CD8 ratios (1.3, p<0.001) compared to blood donors. These differences were due to a group of 14 military personnel with CD4 and CD8 medians of 308 and 266 cells/µl, respectively. Only one (7.1%) of these 14 individuals was diagnosed with clinical stress compared with 13.5% of the individuals with normal levels of CD4 T lymphocytes. One individual out of 628 (0.16%) had a Lipp's Stress Symptom Inventory score of 3, indicating near exhaustion. CONCLUSION: The prevalence of psychological disorders was low and there were no associations with CD4 or CD8 T cell numbers. PMID:25789525

  12. Thymic influence on the T-lymphocyte self MHC repertoire. I. Helper T-lymphocyte precursors.

    PubMed

    Jenski, L J; Belloni, M L; Miller, B A

    1988-01-01

    We measured the frequencies of helper T-cell precursors in spleens of allogeneic thymus-grafted nude mice to determine whether allogeneic thymus engraftment resulted in clonal deletion of helper T-cells reactive to thymic major histocompatibility complex alloantigens, thereby producing tolerance to the thymic alloantigens. C3H thymus-grafted nudes had nearly normal numbers of C3H-reactive helper T-cell precursors, whereas C57BL/6 thymus-grafted nudes had significantly reduced numbers of C57BL/6-reactive helper T-cell precursors. Additional evidence suggested that tolerance was not due to a paucity of helper T-cell precursors: a) there was no correlation between the helper T-cell precursor frequency and the ability to mount cytotoxic responses against the thymic alloantigens, and b) exogenous helper factors did not break cytotoxic T-lymphocyte tolerance to thymic alloantigens. Thus, we conclude that immune tolerance resulting from engraftment of allogeneic thymic tissue is not necessarily due to clonal deletion of specific helper T-cell precursors. PMID:2966463

  13. Resistance of cytotoxic T lymphocytes to lysis by a clone of cytotoxic T lymphocytes.

    PubMed Central

    Kranz, D M; Eisen, H N

    1987-01-01

    To investigate how cytotoxic T lymphocytes (CTL) avoid killing themselves when they destroy target cells, we compared 20 different cell lines as target cells, including several CTL cell lines, for their susceptibility to lysis by CTL. Variations in recognition of this diverse set of target cells was circumvented by attaching to all of them a monoclonal antibody to the antigen-specific receptor of a cloned CTL cell line (clone 2C) and using the 2C cell line as the standard aggressor or effector cell. All of the nine tumor cell lines and the four noncytolytic T-helper cell lines tested as targets were highly susceptible to lysis by the aggressor CTL, but seven cytotoxic T-cell lines (six CTL and one T-helper cell line with cytotoxic activity) were largely resistant. These results, and the use of the lectin Con A as an alternative means for triggering CTL activity, point clearly to a level of resistance that could enable CTL to avoid their own destruction when they lyse target cells. The resistance of the cytolytic T cells did not appear to be accompanied by a similar resistance to complement-mediated lysis, indicating that mechanisms of CTL-mediated and complement-mediated lysis are not identical. PMID:2953028

  14. Peptide specificity and HLA restriction do not dictate lymphokine production by allergen-specific T-lymphocyte clones.

    PubMed Central

    van Neerven, R J; van de Pol, M M; Wierenga, E A; Aalberse, R C; Jansen, H M; Kapsenberg, M L

    1994-01-01

    Human and murine CD4+ T lymphocytes can be subdivided into distinct subsets [T-helper type 0 (Th0), Th1 or Th2], based on their lymphokine production profiles. Not much is known about the factors that determine these restricted lymphokine secretion profiles. Peptide specificity and human leucocyte antigen (HLA) restriction may be such factors. As it is well established that allergen-specific T lymphocytes from atopic individuals and non-atopic controls differ in their lymphokine secretion profile, we studied two allergen-specific T-lymphocyte clones (TLC) with identical peptide specificity and HLA restriction that were generated from the peripheral blood of an atopic donor and a non-atopic control donor. The two CD4+ TLC recognize the same epitope (20-33) of the house dust mite Dermatophagoides pteronyssinus major allergen Der p II. Both TLC recognize the epitope in an HLA-DQB1*0602-restricted manner. However, the lymphokine production profiles of these TLC show clear differences after allergen-specific or polyclonal activation. As expected, TLC JBD4 from the atopic donor produced high levels of interleukin-4 (IL-4) without detectable interferon-gamma (IFN-gamma), whereas TLC PBA1 from the non-atopic donor produced both IFN-gamma and IL-4 upon allergen-specific or polyclonal activation. Inasmuch as both TLC recognized the same epitope of Der p II in association with the same HLA-DQ molecule, these data suggest that peptide specificity and HLA restriction of human allergen-specific TLC do not dictate their lymphokine secretion profile. PMID:7525459

  15. The lysis of cytotoxic T lymphocytes and their blasts by cytotoxic T lymphocytes.

    PubMed Central

    Schick, B; Berke, G

    1990-01-01

    After binding to their targets, cytotoxic T lymphocytes (CTL) deliver a lethal hit signal, ultimately leading to target cell lysis, and then can recycle to lyse additional targets, without themselves being destroyed. If non-specific secreted lytic mediators are involved in such lysis. CTL survival would not be expected unless the effectors are immune to CTL-mediated lysis. Therefore the lytic susceptibilities of alloimmune peritoneal exudate lymphocytes (PEL), containing up to 50% CTL, and of the cytolytic PEL blasts (PEB), obtained by culturing with interleukin-2 (IL-2), were examined. 51Cr-labelled BALB/c (H-2d) anti-EL4 (H-2b) (d alpha b) PEL were lysed 88%, 78%, and 48% by C3H/eb (H-2k) anti-P815 (H-2d) (k alpha d) PEL, C57BL/6 (H-2b) anti-P815 (b alpha d) PEL and b alpha d PEB, respectively. Similarly, b alpha d PEL were lysed 82% and 21% by d alpha b PEL and PEB, respectively. b alpha d PEB were lysed 82%, 28-39% and 39-51% by k alpha d PEL, b alpha d PEL and b alpha d PEB, respectively, b alpha d PEB were lysed 29-55% by d alpha b PEL. Furthermore, the CTL-containing populations were no less susceptible to lysis than normal lymphocytes. Since the majority (80-90%) of cells in these two types of CTL-containing populations can be directly and specifically lysed by appropriately immunized PEL CTL, we conclude that both the lytic granule and perforin lacking (PEL) and containing (PEB) CTL are not a priori immune to CTL-mediated lysis. These findings are in accord with theories proposing lysis to be induced by receptor-mediated contact between effector CTL and target cells, and challenge those suggesting the involvement of secreted lytic mediators. PMID:2269479

  16. Influence of ethanol on human T-lymphocyte migration

    SciTech Connect

    Kaelin, R.M.; Semerjian, A.; Center, D.M.; Bernardo, J.

    1984-11-01

    Because ethanol consumption is associated with increased susceptibility to infection, an examination was made of the effects of ethanol and its metabolite acetaldehyde on human T-lymphocyte migration, an important functional component of cellular inflammatory responses. With a modified Boyden chamber system, ethanol at 0.25% and 0.50% (vol/vol) inhibited spontaneous motility of human T-lymphocytes, in a noncytotoxic manner, to 65% +/- 7% (mean +/- SEM) and 62% +/- 7% of control values of migration, respectively. When T-lymphocyte migration was stimulated by colchicine (10/sup -5/ mol/L), incubation with ethanol (0.25% and 0.50%, vol/vol) decreased migration to 80% +/- 4% and 66% +/- 8% of control values, respectively. Similar degrees of inhibition of migration were obtained with acetaldehyde at concentrations five to 10 times less than ethanol. Ethanol was similarly capable of inhibiting T cell migration induced by dibutyryl cyclic guanosine monophosphate, but it had no effect on stimulated migration induced by a human chemokinetic lymphokine. The study demonstrates that ethanol, at concentrations achievable in vivo, is capable of depressing T-lymphocyte migration. This effect might contribute to the immunosuppression associated with ethanol consumption. 36 references, 4 figures.

  17. Distribution of normal T lymphocytes in tumor-bearing rats.

    PubMed

    Klobusická, M; Koníková, E

    1982-01-01

    Changes in distribution properties of T lymphocytes from lymphoid organs of normal rats 3H-uridine labeled in vitro and i. v. injected to tumor-bearing recipients were studied at different stages of tumor growth and rejection. Comparisons were made with T cell migration from normal donors to syngeneic recipients. A temporary decrease in the ability of normal spleen T lymphocytes to migrate into the spleen of tumor-bearing recipients at early stages of tumor growth was in correlation with their enhancement in trapping by the liver of this recipient. At this stage the migrations into tumor-draining lymph nodes and peripheral blood were rather pronounced. The growing tumor evoked an increased migration rate of donor spleen cells into each of the recipient organs studied except for liver. Tumor rejection potentiated the distribution mainly in the draining lymph node and liver. Normal lymph node T lymphocytes migrated at the beginning of tumor growth into spleen, node and liver of tumor-bearing recipients. A sharp decrease of distribution in spleen at the time of maximum tumor growth was compensated by an enhanced migration into draining nodes, peripheral blood and liver. This enhancement was seen also during tumor rejection. Distribution of normal blood T lymphocytes into spleen and peripheral blood of tumor-bearing recipients was equal to normal values. There was only a transitional reduction in their migration rates into draining nodes caused by tumor growth. Migration rates of thymocytes in tumor-bearing recipients remained unaltered. The results presented indicate that the distribution pattern of i. v. injected labeled T lymphocytes from normal donors into lymphoid organs of tumor-bearing recipients was determined by changes in the immune status of the recipients brought about by tumor development. PMID:6984490

  18. 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

  19. CD45 regulates apoptosis in peripheral T lymphocytes.

    PubMed

    Liu, Zhe; Dawes, Ritu; Petrova, Svetla; Beverley, Peter C L; Tchilian, Elma Z

    2006-06-01

    Programmed cell death (apoptosis) is a key mechanism for regulating lymphocyte numbers. Murine lymph node lymphocytes cultured in vitro without added stimuli show significant levels of apoptosis over 24 h, detectable by staining with Annexin V. CD4 and CD8 T lymphocytes from transgenic (Tg) mice expressing single CD45RABC or CD45RO isoforms show increased apoptosis and the extent of apoptosis is inversely correlated with the level of CD45 expression. CD45 Tg cells exhibit phosphatidyl serine translocation and DNA oligonucleosome formation, and can be partially rescued from apoptosis by culture in caspase inhibitors or common gamma-chain-binding cytokines. We conclude that CD45 is an important regulator of spontaneous apoptosis in T lymphocytes and this mechanism may contribute to the disease associations reported for individuals expressing CD45 variant alleles. PMID:16621865

  20. Furin-processed antigens targeted to the secretory route elicit functional TAP1-/-CD8+ T lymphocytes in vivo.

    PubMed

    Medina, Francisco; Ramos, Manuel; Iborra, Salvador; de León, Patricia; Rodríguez-Castro, Marta; Del Val, Margarita

    2009-10-01

    Most pathogen-derived peptides recognized by CD8+ CTL are produced by proteasomes and delivered to the endoplasmic reticulum by the TAP transporters associated with Ag processing. Alternative proteases also produce antigenic peptides, but their actual relevance is unclear. There is a need to quantify the contribution of these supplementary pathways in vitro and in vivo. A well-defined TAP-independent secretory route of Ag processing involves the trans-Golgi network protease furin. Quantitation of this route by using OVA constructs encoded by vaccinia viruses indicates that it provides approximately one-third of all surface complexes of peptide and MHC class I molecules. Generation of the epitope carboxyl terminus is a dramatic rate-limiting step, since bypassing it increased efficiency by at least 1000-fold. Notably, the secretory construct activated a similar percentage of Ag-specific CD8+ T cells in wild type as in TAP1-deficient mice, which allow only secretory routes but which have a 10- to 20-fold smaller CD8 compartment. Moreover, these TAP1(-/-) OVA-specific CD8+ T lymphocytes accomplished elimination of epitope-bearing cells in vivo. The results obtained with this experimental system underscore the potential of secretory pathways of MHC class I Ag presentation to elicit functional CD8+ T lymphocytes in vivo and support the hypothesis that noncytosolic processing mechanisms may compensate in vivo for the lack of proteasome participation in Ag processing in persons genetically deficient in TAP and thus contribute to pathogen control. PMID:19752221

  1. Peripheral blood T-lymphocyte subsets in autoimmune thyroid disease.

    PubMed

    Covas, M I; Esquerda, A; García-Rico, A; Mahy, N

    1992-01-01

    Interest in T-lymphocyte subsets has arisen because of their involvement in the autoimmune process. Contradictory results have been published in the literature about the number of peripheral blood lymphocyte subsets in autoimmune diseases. In order to investigate the number and distribution of peripheral blood lymphocyte subsets in autoimmune thyroid disease, the levels of total T-lymphocytes (CD3), T-helper (CD4) and T-suppressor/cytotoxic (CD8) lymphocytes were determined in 44 patients with Graves' disease (1), multinodular goiter (2) and Hashimoto's thyroiditis (3). All patients had high levels of antithyroglobulin and thyroid antiperoxidase (antimicrosomal) antibodies. The T subset levels were related to the functional thyroid status, measured as serum free thyroxine (FT4) and thyrotropin (TSH). Our data show the existence of a strong influence of functional status on CD3, CD4 and CD8 levels, as reflected in the significant correlations obtained with FT4 (negative) and TSH (positive). A significant decrease in all populations was observed in Graves' disease hyperthyroid patients. A decrease in the CD4/CD8 ratio in Hashimoto's thyroiditis hypothyroid patients was observed, in contrast to an increase in the ratio in autoimmune hyperthyroid patients. This points to the CD4/CD8 ratio as a differential characteristic between the two autoimmune (hypothyroid and hyperthyroid) entities, independent of free thyroxine levels. No significant correlation was found between antithyroid antibody levels and peripheral blood T-lymphocyte subsets or serum levels of FT4 and TSH. PMID:1342892

  2. Control of T lymphocyte morphology by the GTPase Rho

    NASA Technical Reports Server (NTRS)

    Woodside, Darren G.; Wooten, David K.; Teague, T. Kent; Miyamoto, Yuko J.; Caudell, Eva G.; Udagawa, Taturo; Andruss, Bernard F.; McIntyre, Bradley W.

    2003-01-01

    BACKGROUND: Rho family GTPase regulation of the actin cytoskeleton governs a variety of cell responses. In this report, we have analyzed the role of the GTPase Rho in maintenance of the T lymphocyte actin cytoskeleton. RESULTS: Inactivation of the GTPase Rho in the human T lymphocytic cell line HPB-ALL does not inhibit constitutively high adhesion to the integrin beta1 substrate fibronectin. It did however result in the aberrant extension of finger-like dendritic processes on the substrates VCAM-1, Fn, and mAb specific to beta1 integrins. Time-lapse video microscopy demonstrated that C3 induced extensions were primarily the result of an altered pseudopod elongation rather than retraction. Once the stellate pseudopodia extended, none retracted, and cells became completely immobile. Filipodial structures were absent and the dendritic-like processes in C3 treated cells were rich in filamentous actin. Immunolocalization of RhoA in untreated HPB-ALL cells spreading on fibronectin demonstrated a diffuse staining pattern within the pseudopodia. In C3 treated cells, clusters of RhoA were pronounced and localized within the altered extensions. CONCLUSIONS: GTPase Rho is actively involved in the regulation of T lymphocyte morphology and motility.

  3. T-lymphocyte induction of human monocyte angiotensin converting enzyme (ACE) is not dependent upon T-lymphocyte proliferation

    SciTech Connect

    Vuk-Pavlovic, Z.; Rohrbach, M.S.

    1986-03-05

    Human peripheral blood monocytes cultured in serum free media for seven days show a basal activity of the ectoenzyme ACE which is augmented 2-3 times by the presence of autologous peripheral blood T-lymphocytes. Since these two cell types are also involved in autologous mixed lymphocyte reaction if serum is present, the authors compared the ability of T-cells to stimulate ACE activity in the presence or absence of proliferation (measured by /sup 3/H-thymidine incorporation). By the seventh day, cultures with 5% AB/sup +/ serum showed significant increase in proliferation but no increase in ACE activity compared to the serum free cultures. Even higher proliferation rate achieved by co-culturing T-lymphocytes with allogeneic monocytes did not increase ACE production; on the contrary, ACE activity remained at the basal level. Monocyte-T-cell co-cultures stimulated with increasing concentrations of ConA or PHA showed dose dependent increases in proliferation but parallel decreases in ACE activity. Addition of soluble antigen (Candida albicans) also enhanced proliferation but not ACE synthesis. They conclude that T-lymphocyte induction of monocyte ACE is a result of cooperation between autologous cells which is not dependent upon T-cell proliferation.

  4. Induction of single and dual cytotoxic T-lymphocyte responses to viral proteins in mice using recombinant hybrid Ty-virus-like particles.

    PubMed

    Layton, G T; Harris, S J; Myhan, J; West, D; Gotch, F; Hill-Perkins, M; Cole, J S; Meyers, N; Woodrow, S; French, T J; Adams, S E; Kingsman, A J

    1996-02-01

    The induction of cytotoxic T-lymphocyte (CTL) responses to viral proteins is thought to be an essential component of protective immunity against viral infections. Methods for generating such responses in a reproducible manner would be of great value in vaccine development. We demonstrate here that the recombinant antigen-presentation system based on the yeast transposon (Ty) particle-forming p1 protein is a potent means of inducing CTL responses to a variety of viral CTL epitopes, including influenza virus nucleoprotein (two epitopes), Sendai virus and vesicular stomatitis virus nucleoproteins, and the V3 loop of human immunodeficiency virus type-1 (HIV-1) gp120. CTL were primed by hybrid Ty-virus-like particles (VLP) carrying the minimal epitope or as much as 19,000 MW of protein. Ty-VLP carrying two different epitopes (dual-epitope Ty-VLP) were capable of priming CTL responses in two different strains of mice or against two epitopes in the same individual. Furthermore, co-administration of a mixture of two different Ty-VLP carrying single epitopes could induce responses to both epitopes in the same individual. Ty-VLP appear to represent a reproducible and flexible system for inducing CTL responses in mice, and warrant further evaluation in primates. PMID:8698376

  5. Effect of cimetidine on burst-promoting activity of normal T lymphocytes.

    PubMed

    Morra, L; Moccia, F; Casti, P; Bessone, G; Ponassi, G A

    1992-05-01

    The effect of cimetidine, an inhibitor of suppressor T lymphocytes, on the burst-promoting activity (BPA) of normal T lymphocytes has been studied. Cimetidine has been shown to increase the BPA of normal T lymphocytes, both when added to the culture and when T lymphocytes were preincubated for 1 h with it. Cimetidine had no direct effect on the in vitro growth of burst-forming units (BFU-E). Our results show that CD8 suppressor T lymphocytes inhibit the in vitro growth of BFU-E in normal conditions, either directly or through inhibition of BPA of CD4 helper T lymphocytes. Cimetidine has proved to be a useful tool for investigating the hematological role of T-lymphocyte subsets in normal and pathological conditions. PMID:1623056

  6. 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

  7. 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. PMID:27505426

  8. Clonal dominance among T-lymphocyte infiltrates in arthritis

    SciTech Connect

    Stamenkovic, I.; Stegagno, M.; Wright, K.A.; Krane, S.M.; Amento, E.P.; Colvin, R.B.; Duquesnoy, R.J.; Kurnick, J.T.

    1988-02-01

    Synovial membranes in patients with rheumatoid arthritis as well as other types of chronic destructive inflammatory arthritis contain infiltrates of activated T lymphocytes that probably contribute to the pathogenesis of the disease. In an effort to elucidate the nature of these infiltrates, interleukin 2 (IL-2)-responsive T lymphocytes were grown out of synovial fragments from 14 patients undergoing surgery for advanced destructive inflammatory joint disease. Eleven of the samples examined were from patients with classical rheumatoid arthritis, while three others were obtained from individuals with clinical osteoarthritis. Southern blot analysis of T-cell receptor (TCR) ..beta..-chain genes in 13 of 14 cultures showed distinct rearrangements, indicating that each culture was characterized by the predominance of a limited number of clones. T-cell populations from peripheral blood stimulated with a variety of activators and expanded with IL-2 did not demonstrate evidence of similar clonality in long-term culture. These results suggest that a limited number of activated T-cell clones predominate at the site of tissue injury in rheumatoid synovial membranes as well as in other types of destructive inflammatory joint disease. Further characterization of these T-cell clones may aid our understanding of the pathogenesis of these rheumatic disorders.

  9. Cross-reactivity of sperm and T lymphocyte antigens.

    PubMed

    Mathur, S; Goust, J M; Williamson, H O; Fudenberg, H H

    1981-01-01

    Evidence is presented for cross-reactivity between antigens on human sperm and T lymphocytes. In 25 infertile couples in which both the males and females had significant antisperm immunity, antibody (Ab) titers to thymocytes (mean +/- S.E.M. 159 +/- 4 and 72 +/- 14, respectively, in males and females), T cell lines CCRF-CEM (69 +/- 5 and 48 +/- 8) and HSB-2 (56 +/- 15) and 41 +/- 8), suppressor-enriched (TG) cells (26 +/- 6 and 66 +/- 28) and helper-enriched (TG-) cells (26 +/- 4 and 46 +/- 14) were significantly elevated, as compared with Ab titers in 45 normal males and 45 normal females without antisperm immunity. Antibody titers to adult B cells, B cell line RAJI, and granulocytes were similar in the two groups. Antisperm Ab titers in sera, sperm extracts, and seminal plasma of the infertile subjects were significantly reduced after absorption with sperm, thymocytes, or T cell line CCRF-CEM but not with the B cell line RAJI. Antithymocyte Ab titers in the sera were significantly reduced (p less than 0.001) after absorption with thymocytes, CCRF-CEM, or sperm, but not RAJI. Lymphocytes from the infertile patients, when stimulated with pokeweed mitogen in vitro, produced antisperm and anti-T-lymphocyte antibodies at significantly higher titers than normal controls. PMID:6175235

  10. Dehydroepiandrosterone and metformin regulate proliferation of murine T lymphocytes

    PubMed Central

    Solano, M E; Sander, V; Wald, M R; Motta, A B

    2008-01-01

    The aim of the present study was to assess the effect of dehydroepiandrosterone (DHEA: 10 µM) and metformin (10 µM and 100 µM) in regulating proliferation of cultured T lymphocytes. T cells were isolated from lymph nodes of prepuberal BALB/c mice. We found that DHEA, metformin and DHEA + metformin added to the incubation media diminished proliferation of T cells. The inhibition by DHEA was higher than that produced by metformin, while the combined treatment showed a synergistic action that allowed us to speculate distinct regulatory pathways. This was supported later by other findings in which the addition of DHEA to the incubation media did not modify T lymphocyte viability, while treatment with metformin and DHEA + metformin diminished cellular viability and increased both early and late apoptosis. Moreover, DHEA diminished the content of the anti-oxidant molecule glutathione (GSH), whereas M and DHEA + metformin increased GSH levels and diminished lipid peroxidation. We conclude that DHEA and metformin diminish proliferation of T cells through different pathways and that not only the increase, but also the decrease of oxidative stress inhibited proliferation of T cells, i.e. a minimal status of oxidative stress, is necessary to trigger cellular response. PMID:18549441

  11. D-Limonene modulates T lymphocyte activity and viability.

    PubMed

    Lappas, Courtney M; Lappas, Nicholas T

    2012-09-01

    d-Limonene, a cyclic terpene that is a major component of several plant essential oils, is used widely as an additive in perfumes, soaps, foods and beverages, and has also been shown to possess chemopreventative and chemotherapeutic activity. A limited number of studies have been conducted investigating the effect of d-limonene on immune system function. We show that d-limonene and its metabolites limonene-1-2-diol and perillic acid inhibit the production by CD3(+)CD4(+) T cells of IFN-γ, IL-2, TNF-α, IL-4 and IL-13, and the production by CD3(+)CD8(+) T cells of IFN-γ, IL-2, and TNF-α. Additionally, the upregulation of CD25, CD69 and CD40L by activated T lymphocytes is modulated by d-limonene, limonene-1-2-diol and perillic acid treatment. Furthermore, high concentrations of d-limonene, limonene-1-2-diol and perillic acid induce T lymphocyte cell death. These data suggest that d-limonene possesses immunomodulatory activity that must be considered when utilizing the compound for therapeutic or commercial purposes. PMID:23059811

  12. Mechanisms of T Lymphocyte Activation Exposed by Super Resolution Microscopy

    NASA Astrophysics Data System (ADS)

    Campanello, Leonard; Losert, Wolfgang; Traver, Maria; Schaefer, Brian; York, Andrew; Schroff, Hari

    In order to avoid the deleterious consequences of an uncontrolled immune response, tight regulatory control of positive and negative regulators during lymphocyte activation is needed. Utilizing cutting-edge super-resolution imaging technologies in combination with quantitative image analysis we explore the interplay between positive and negative regulation in activated T lymphocytes and investigate whether intercellular signaling is possibly governed by the degradation of a complex intracellular structure called the POLKADOTS signalosome. In segmenting the POLKADOTS signalosome structure by the betweenness centrality of its 3D medial axis skeleton, it was discovered that autophagosomes, small degradative intracellular organelles, localize preferentially to the ends of the filamentous POLKADOTS signalosome. These results provide new insight into the mechanisms behind the complex regulatory process that govern T lymphocyte activation. This research was supported by an Irvington Postdoctoral Fellowship from the Cancer Research Institute (awarded to MT) and a U01 Grant from the National Institutes of Health (GM109887-01, awarded to BS and WL).

  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. A self-adjuvanting vaccine induces cytotoxic T lymphocytes that suppress allergy.

    PubMed

    Anderson, Regan J; Tang, Ching-wen; Daniels, Naomi J; Compton, Benjamin J; Hayman, Colin M; Johnston, Karen A; Knight, Deborah A; Gasser, Olivier; Poyntz, Hazel C; Ferguson, Peter M; Larsen, David S; Ronchese, Franca; Painter, Gavin F; Hermans, Ian F

    2014-11-01

    Epitope-based peptide vaccines encompass minimal immunogenic regions of protein antigens to allow stimulation of precisely targeted adaptive immune responses. However, because efficacy is largely determined by the functional status of antigen-presenting cells (APCs) that acquire and present peptides to cells of the adaptive immune system, adjuvant compounds are needed to enhance immunogenicity. We present here a vaccine consisting of an allergen-derived peptide conjugated to a prodrug of the natural killer-like T (NKT) cell agonist α-galactosylceramide, which is highly effective in reducing inflammation in a mouse model of allergic airway inflammation. Unlike other peptide-adjuvant conjugates that directly activate APCs through pattern recognition pathways, this vaccine encourages third-party interactions with NKT cells to enhance APC function. Therapeutic efficacy was correlated with marked increases in the number and functional activity of allergen-specific cytotoxic T lymphocytes (CTLs), leading to suppression of immune infiltration into the lungs after allergen challenge in sensitized hosts. PMID:25282504

  15. Dendritic cells cross-present HIV antigens from live as well as apoptotic infected CD4+ T lymphocytes

    NASA Astrophysics Data System (ADS)

    Marañón, Concepción; Desoutter, Jean-François; Hoeffel, Guillaume; Cohen, William; Hanau, Daniel; Hosmalin, Anne

    2004-04-01

    A better understanding of the antigen presentation pathways that lead to CD8+ T cell recognition of HIV epitopes in vivo is needed to achieve better immune control of HIV replication. Here, we show that cross-presentation of very small amounts of HIV proteins from apoptotic infected CD4+ T lymphocytes by dendritic cells to CD8+ T cells is much more efficient than other known HIV presentation pathways, i.e., direct presentation of infectious virus or cross-presentation of defective virus. Unexpectedly, dendritic cells also take up actively antigens into endosomes from live infected CD4+ T lymphocytes and cross-present them as efficiently as antigens derived from apoptotic infected cells. Moreover, live infected CD4+ T cells costimulate cross-presenting dendritic cells in the process. Therefore, dendritic cells can present very small amounts of viral proteins from infected T cells either after apoptosis, which is frequent during HIV infection, or not. Thus, if HIV expression is transiently induced while costimulation is enhanced (for instance after IL-2 and IFN immune therapy), this HIV antigen presentation pathway could be exploited to eradicate latently infected reservoirs, which are poorly recognized by patients' immune systems.

  16. [Down-regulation of TIPE2 promotes the proliferation and immune activity of T lymphocytes].

    PubMed

    Huang, Lihong; Chen, Jiangyong; Hong, Bin

    2016-07-01

    Objective To utilize specific small interfering RNA (siRNA) to silence the expression of tumor necrosis factor α-induced protein 8 like-2 (TIPE2) gene of T lymphocytes and investigate the effect of TIPE2 targeting siRNA on T lymphocyte proliferation and immune function. Methods Mouse spleen T lymphocytes were sorted by magnetic beads. Western blotting was used to screen and validate an effective siRNA to silence the TIPE2 gene expression of T lymphocytes. Twenty-four hours after transfection with the siRNA into T lymphocytes, the expression of CD69 in each group was detected by flow cytometry. Seventy-two hours after transfection, the proliferation of the T lymphocytes was measured with CCK-8 assay; meanwhile, the secretion levels of interleukin 2 (IL-2) and interferon γ (IFN-γ) in each group were measured by ELISA. Results We obtained TIPE2 targeting siRNA sequences and effectively silenced the expression of TIPE2 gene. After TIPE2 gene expression was down-regulated, the expression of the CD69 on T lymphocytes increased, and the proliferation of T lymphocytes and the secretion of IL-2 and IFN-γ were enhanced. Conclusion Down-regulation of TIPE2 gene expression can promote the T lymphocyte proliferation and immune activity. PMID:27363266

  17. 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

  18. Herpesvirus sylvilagus infects both B and T lymphocytes in vivo.

    PubMed

    Kramp, W J; Medveczky, P; Mulder, C; Hinze, H C; Sullivan, J L

    1985-10-01

    Herpesvirus sylvilagus infection of cottontail rabbits (Sylvilagus floridanus) was studied as a model of herpesvirus-induced lymphoproliferative disorders. Leukocytosis, splenomegaly, proliferation of T cells and virus production by lymphocytes characterized this infectious mononucleosis-like disease. Approximately two copies of circular herpesvirus sylvilagus genomes per cell were detected in spleen cells at 2 weeks postinfection, and circular genomes could still be observed after 4 months. Circular viral genomes were found in both B and T lymphocytes. Small amounts of linear viral DNA (0.1 to 0.3 copies per cell) were also detected in both B and T cells. These results indicated that the virus did not replicate in the majority of lymphocytes in vivo. Herpesvirus sylvilagus infection in cottontail rabbits could be useful as a model for studying the complex virus-host relationships of lymphotropic herpesviruses and perhaps as an animal model for Epstein-Barr virus infection in humans. PMID:2993667

  19. Stable growth transformation of human T lymphocytes by herpesvirus saimiri.

    PubMed Central

    Biesinger, B; Müller-Fleckenstein, I; Simmer, B; Lang, G; Wittmann, S; Platzer, E; Desrosiers, R C; Fleckenstein, B

    1992-01-01

    Herpesvirus saimiri induces T-cell lymphomas in various species of New World monkeys and in rabbits, and it is able to immortalize monkey T lymphocytes in vitro. Sequences responsible for these effects have been localized to a region of the genome that varies significantly among the virus subgroups A, B, and C. We now report that infection of human blood lymphocytes and thymocytes with strains of subgroup C, in contrast to viruses of the other subgroups, yields continuously proliferating T-cell lines with the phenotype of mature CD4- or CD8-positive cells. Infection with strains of Herpes-virus saimiri subgroup C can thus be used to generate human T-cell lines for a variety of immunological and developmental studies. Images PMID:1313581

  20. Herpesvirus sylvilagus infects both B and T lymphocytes in vivo.

    PubMed Central

    Kramp, W J; Medveczky, P; Mulder, C; Hinze, H C; Sullivan, J L

    1985-01-01

    Herpesvirus sylvilagus infection of cottontail rabbits (Sylvilagus floridanus) was studied as a model of herpesvirus-induced lymphoproliferative disorders. Leukocytosis, splenomegaly, proliferation of T cells and virus production by lymphocytes characterized this infectious mononucleosis-like disease. Approximately two copies of circular herpesvirus sylvilagus genomes per cell were detected in spleen cells at 2 weeks postinfection, and circular genomes could still be observed after 4 months. Circular viral genomes were found in both B and T lymphocytes. Small amounts of linear viral DNA (0.1 to 0.3 copies per cell) were also detected in both B and T cells. These results indicated that the virus did not replicate in the majority of lymphocytes in vivo. Herpesvirus sylvilagus infection in cottontail rabbits could be useful as a model for studying the complex virus-host relationships of lymphotropic herpesviruses and perhaps as an animal model for Epstein-Barr virus infection in humans. Images PMID:2993667

  1. T lymphocyte killing by a xanthine-oxidase-containing immunotoxin.

    PubMed

    Battelli, M G; Abbondanza, A; Tazzari, P L; Bolognesi, A; Lemoli, R M; Stirpe, F

    1992-01-01

    We report on the preparation of an immunotoxin consisting of xanthine oxidase, a free-radical-producing enzyme, covalently linked to an anti-CD3 monoclonal antibody. The immunotoxin retained both enzymic and immunological properties and its toxicity to target cells (a) was greater than that of the free enzyme, (b) was proportional to the enzyme concentration, and (c) was reduced either in the absence of hypoxanthine or by an excess of free anti-CD3 monoclonal antibody. The cytotoxicity and selectivity of the hypoxanthine/conjugated xanthine oxidase system were potentiated by the addition of chelated iron and by washing away the unbound immunotoxin prior to the addition of substrate. The same system was not toxic to bone marrow progenitor cells. A possible use of this immunotoxin for the ex vivo purging of organs to be transplanted from T lymphocytes, to avoid the graft-versus-host reaction, is suggested. PMID:1394345

  2. T lymphocytes in the murine vaginal mucosa are phenotypically distinct from those in the periphery.

    PubMed Central

    Fidel, P L; Wolf, N A; KuKuruga, M A

    1996-01-01

    The results from both clinical studies of women with recurrent vulvovaginal candidiasis and a murine model of experimental vaginitis indicate that systemic cell-mediated immunity may not represent a dominant host defense mechanism against vaginal infections by Candida albicans. Recent experimental evidence indicates the presence of local vaginal immune reactivity against C. albicans. The present study was designed to examine T-lymphocyte subpopulations in the vaginal mucosae of naive CBA/J mice. Vaginal lymphocytes (VL) were isolated by collagenase digestion of whole vaginal tissues. Cell populations were identified by flow cytometry, and the results were compared with those for both lymph node cells (LNC) and peripheral blood lymphocytes (PBL). The results of flow cytometry showed that 45% +/- 10% of lymphocytes in the vaginal mucosa are CD3+ compared with 75% +/- 5% in LNC and 50% +/- 5% in PBL. The majority (85%) of CD3+ VL are CD4+ and express the alpha/beta T-cell receptor (TCR), similar to the results for LNC and PBL. In contrast to LNC and PBL, VL contain a significantly higher percentage (15 to 20%) of gamma/delta TCR+ cells, 80% or more of which appear to express CD4. In addition, while CD4-CD8 cell ratios in LNC and PBL were 3:1 and 6:1, respectively, only 1% of VL expressed CD8, resulting in a CD4-CD8 cell ratio of > 100:1. Finally, while LNC and PBL recognized two epitope-distinct (GK 1.5 and 2B6) anti-CD4 antibodies, VL recognized only 2B6 anti-CD4 antibodies. Further analysis of VL showed that Thy-1 cells, but not CD4 cells, were reduced after intravaginal injection of complement-fixing anti-Thy-1.2 and GK 1.5 anti-CD4 antibodies, respectively. Taken together, these data suggest that T lymphocytes in the vaginal mucosae of mice are phenotypically distinct from those in the periphery and that CD4+ VL have an uncharacteristic or atypical expression of the CD4 receptor. PMID:8751931

  3. REDOX-REGULATED SUPPRESSION OF SPLENIC T-LYMPHOCYTE ACTIVATION IN A MODEL OF SYMPATHOEXCITATION

    PubMed Central

    Case, Adam J.; Zimmerman, Matthew C.

    2015-01-01

    Sympathoexcitation, increased circulating norepinephrine, and elevated levels of reactive oxygen species are driving forces underlying numerous cardiovascular diseases including hypertension. However, the effects of elevated norepinephrine and subsequent reactive oxygen species production in splenic T-lymphocytes during hypertension are not currently understood. We hypothesized that increased systemic levels of norepinephrine inhibits the activation of splenic T-lymphocytes via redox signaling. To address this hypothesis, we examined the status of T-lymphocyte activation in spleens of a mouse model of sympathoexcitation-driven hypertension (i.e. norepinephrine infusion). Splenic T-lymphocytes from norepinephrine-infused mice demonstrated decreased proliferation accompanied by a reduction in interferon gamma and tumor necrosis factor alpha production as compared to T-lymphocytes from saline-infused mice. Additionally, norepinephrine directly inhibited splenic T-lymphocyte proliferation and cytokine production ex vivo in a dose dependent manner. Furthermore, norepinephrine caused an increase in G1 arrest in norepinephrine-treated T-lymphocytes, and this was accompanied by a decrease in pro-growth cyclin D3, E1, and E2 mRNA expression. Interestingly, norepinephrine caused an increase in cellular superoxide, which was shown to be partially-causal to the inhibitory effects of norepinephrine as antioxidant supplementation (i.e. Tempol) to norepinephrine-infused mice moderately restored T-lymphocyte growth and pro-inflammatory cytokine production. Our findings indicate that suppression of splenic T-lymphocyte activation occurs in a norepinephrine-driven model of hypertension due to, at least in part, an increase in superoxide. We speculate that further understanding of how norepinephrine mediates its inhibitory effects on splenic T-lymphocytes may elucidate novel pathways for therapeutic mimicry to suppress T-lymphocyte-mediated inflammation in an array of diseases. PMID

  4. Proliferation and Foxp3 Expression in Virus-Specific Memory CD8+ T Lymphocytes

    PubMed Central

    Hoji, Aki; Coro, Alfonso; Ng, Hwee L.; Jamieson, Beth D.

    2008-01-01

    Abstract Foxp3 plays a critical role in development of CD4+ regulatory T lymphocytes (Tregs). It was originally proposed as a specific marker for Tregs, but recent studies have shown that Foxp3 can be expressed in proliferating CD8+ and CD4+ T lymphocytes. We further investigated the association between Foxp3 expression and proliferation of peripheral blood CD4+ and CD8+ T lymphocytes and focused on virus-specific memory CD8+ T lymphocytes. We found that resting peripheral blood bulk and cytomegalovirus- or HIV-1-specific CD8+ T lymphocytes do not normally express Foxp3. However, stimulation in vitro triggered these cells to express Foxp3 as well as CD25, and the addition of interleukin-2 possibly enhanced the expression of Foxp3. These data demonstrate that proliferation itself is sufficient to induce the Treg-like phenotype. Given that others have demonstrated Treg functional activity in such “induced Tregs,” these results suggest that virus-specific CD8+ T lymphocytes have the capacity to acquire regulatory functions. Although the implications of Foxp3 expression in virus-specific CD8+ T lymphocytes in the immunologic control of persistent HIV-1 viremia remain to be determined, our results are consistent with Foxp3 expression playing an essential role in regulation of cell proliferation and functional outcomes for HIV-1-specific CD8+ T lymphocytes. PMID:18620494

  5. Viral Engineering of Chimeric Antigen Receptor Expression on Murine and Human T Lymphocytes.

    PubMed

    Hammill, Joanne A; Afsahi, Arya; Bramson, Jonathan L; Helsen, Christopher W

    2016-01-01

    The adoptive transfer of a bolus of tumor-specific T lymphocytes into cancer patients is a promising therapeutic strategy. In one approach, tumor specificity is conferred upon T cells via engineering expression of exogenous receptors, such as chimeric antigen receptors (CARs). Here, we describe the generation and production of both murine and human CAR-engineered T lymphocytes using retroviruses. PMID:27581020

  6. Sexual transmission of single human immunodeficiency virus type 1 virions encoding highly polymorphic multisite cytotoxic T-lymphocyte escape variants.

    PubMed

    Milicic, Anita; Edwards, Charles T T; Hué, Stéphane; Fox, Julie; Brown, Helen; Pillay, Tilly; Drijfhout, Jan W; Weber, Jonathan N; Holmes, Edward C; Fidler, Sarah J; Zhang, Hua-Tang; Phillips, Rodney E

    2005-11-01

    Antigenic variation inherent in human immunodeficiency virus type 1 (HIV-1) virions that successfully instigate new infections transferred by sex has not been well defined. Yet this is the viral "challenge" which any vaccine-induced immunity must deal with. Closely timed comparisons of the virus circulating in the "donor" and that which initiates new infection are difficult to carry out rigorously, as suitable samples are very hard to get in the face of ethical hurdles. Here we investigate HIV-1 variation in four homosexual couples where we sampled blood from both parties within several weeks of the estimated transmission event. We analyzed variation within highly immunogenic HIV-1 internal proteins encoding epitopes recognized by cytotoxic T lymphocytes (CTLs). These responses are believed to be crucial as a means of containing viral replication. In the donors we detected virions capable of evading host CTL recognition at several linked epitopes of distinct HLA class I restriction. When a donor transmitted escape variants to a recipient with whom he had HLA class I molecules in common, the recipient's CTL response to those epitopes was prevented, thus impeding adequate viral control. In addition, we show that even when HLA class I alleles are disparate in the transmitting couple, a single polymorphism can abolish CTL recognition of an overlapping epitope of distinct restriction and so confer immune escape properties to the recipient's seroconversion virus. In donors who are themselves controlling an early, acute infection, the precise timing of onward transmission is a crucial determinant of the viral variants available to compose the inoculum. PMID:16254331

  7. IL-10 inhibits alloreactive cytotoxic T lymphocyte generation in vivo.

    PubMed

    Wang, L; Goillot, E; Tepper, R I

    1994-12-01

    In this report, we present evidence that the CTL response directed against MHC Class I allo-determinants can be inhibited as a result of IL-10 expression in vivo. The presence of localized IL-10 secretion at the site of allogeneic tumor cell challenge resulted in marked inhibition of the CTL response and allowed growth of the tumor in the allogeneic host. Using purified CD4+ T cells from mice immunized in the presence or absence of IL-10, we have shown that the loss of alloreactivity as a consequence of IL-10 expression results from the inhibition of CD4+ T cell function. The expression of either IL-2 or IFN-gamma with IL-10 locally at the time of allogeneic cell challenge completely restored CTL alloreactivity, suggesting that the action of IL-10 could be bypassed by providing helper T lymphocyte-derived cytokines of the Th1 type at the site of immunization. Inhibition of alloreactivity by IL-10 was observed using either purified macrophages or dendritic cells as APC in an in vitro assay. Thus, the expression of IL-10 following antigenic challenge (such as that observed in Th2-like immune responses) may profoundly limit the ability for generating functional CTL in vivo. PMID:7994751

  8. Specific binding of antigen onto human T lymphocytes

    SciTech Connect

    Durandy, A.; Fischer, A.; Charron, D.; Griscelli, C.

    1986-05-01

    Human T lymphocytes sensitized to Candida albicans (CA) were shown to proliferate in cultures induced with mannan, a ramified polysaccharide extracted from the cell well of CA. We presently describe that, when we used strongly labeled (/sup 3/H)mannan, antigen-specific T blast cells were able to bind the labeled mannan on their membrane. The observations that irrelevant blast cells did not bind (/sup 3/H)mannan, and that mannan-specific blast cells did not bind tritiated pneumococcal polysaccharide SIII, indicate the specificity of mannan binding. Mannan binding was reversible and saturable. Mannan binding on T blast cells was inhibited by preincubation with monoclonal antibodies to T3 but not to other T cell-related molecules. The characteristics of this receptor suggest its identity with the T cell receptor for antigen. The direct binding of mannan could be either due to a cross-linking of the receptor by multivalent mannan or to a recognition of mannan in association with HLA-DQ molecules, as suggested by partial blocking of mannan binding using anti-HLA-DQ monoclonal antibodies.

  9. Early activation defects in T lymphocytes from aged mice.

    PubMed

    Miller, R A; Garcia, G; Kirk, C J; Witkowski, J M

    1997-12-01

    Aging affects both calcium signals and protein kinase cascades in mouse T lymphocytes. The decline in calcium signal development largely represents differences between naive and memory T cells; the latter are resistant to increases in calcium concentration, and are more common in aged mice. Aging leads to declines in phosphorylation of a wide range of substrates in T cells stimulated by either anti-CD3 antibodies or by substances, such as phorbol myristate acetate (PMA) or ionomycin, that act at intracellular sites, but some phosphoproteins respond only in old T cells, and others respond regardless of age. Tyrosine phosphorylation of the CD3 zeta chain declines with age, both in resting T cells and after activation, but the proportion of Zap-70 that is bound to CD3 zeta increases in T cells from old mice. Zap-70 function and phosphorylation of CD3 zeta-associated Zap-70 change only slightly after stimulation of T cells by anti-CD3 and anti-CD4, and are at similar levels in activated old and young T cells. Nonetheless, induction of Raf-1, MEK, and ERK kinase activity declines with age in CD4 T cells. The effect of aging on T-cell activation is not simply an overall decline in signal intensity, but a set of qualitative changes that differ among subsets and depend at least partly on the nature of the stimulus. PMID:9476667

  10. Cytolytic effector function is present in resting peripheral T lymphocytes.

    PubMed

    Geisberg, M; Dupont, B

    1992-11-01

    Antigen-specific cytotoxic killer lymphocytes (CTLs) represent one of the major effector functions of the immune system. It is well established that, as a consequence of TCR recognition of the antigen-bearing target cell, resting T lymphocytes develop into fully active antigen-specific CTLs. In contrast, natural killer (NK) cells are immediately lytic upon contact with an appropriate target cell. The lytic machinery of CTLs and NK cells is thought to include the contents of their cytoplasmic granules, in particular the pore-forming protein perforin. Here we report direct cytolytic activity by resting peripheral CD3+CD8+ T cells as a result of TCR-CD3 binding to the target cell; the murine OKT3 hybridoma (anti-human CD3) was used as a target. The cytotoxicity was more pronounced in the CD8+CD45RO+ population, which contains 'memory' T cells, than in the reciprocal CD8+CD45RA+ subset; CD8+CD4- mature thymocytes were non-cytotoxic. The cytolytic potential of these populations correlated with the presence or absence of perforin. The results demonstrate that the cytolytic machinery of T cells develops post-thymically and can be immediately triggered by TCR-CD3 stimulation. PMID:1472478

  11. Functional aortic stiffness: role of CD4+ T lymphocytes

    PubMed Central

    Majeed, Beenish A.; Eberson, Lance S.; Tawinwung, Supannikar; Larmonier, Nicolas; Secomb, Timothy W.; Larson, Douglas F.

    2015-01-01

    The immune system is suggested to be essential in vascular remodeling and stiffening. To study the dependence upon lymphocytes in vascular stiffening, we compared an angiotensin II-model of vascular stiffening in normal C57BL/6J mice with lymphocyte-deficient RAG 1−/− mice and additionally characterized the component of vascular stiffness due to vasoconstriction vs. vascular remodeling. Chronic angiotensin II increased aortic pulse wave velocity, effective wall stiffness, and effective Young's modulus in C57BL/6J mice by three-fold but caused no change in the RAG 1−/− mice. These functional measurements were supported by aortic morphometric analysis. Adoptive transfer of CD4+ T helper lymphocytes restored the angiotensin II-mediated aortic stiffening in the RAG 1−/− mice. In order to account for the hydraulic vs. material effects of angiotensin II on pulse wave velocity, subcutaneous osmotic pumps were removed after 21 days of angiotensin II-infusion in the WT mice to achieve normotensive values. The pulse wave velocity (PWV) decreased from three- to two-fold above baseline values up to 7 days following pump removal. This study supports the pivotal role of the CD4+ T-lymphocytes in angiotensin II-mediated vascular stiffening and that angiotensin II-mediated aortic stiffening is due to the additive effect of active vascular smooth muscle vasoconstriction and vascular remodeling. PMID:26379554

  12. The Role of CD8 T Lymphocytes in Rickettsial Infections

    PubMed Central

    Walker, David H.; Dumler, J. Stephen

    2015-01-01

    Arthropod-borne obligately intracellular bacteria pose a difficult challenge to the immune system. The genera Rickettsia, Orientia, Ehrlichia, and Anaplasma evolved mechanisms of immune evasion, and each interacts differently with the immune system. The roles of CD8 T cells include protective immunity and immunopathology. In Rickettsia infections, CD8 T cells are protective mediated in part by cytotoxicity toward infected cells. In contrast, TNFα overproduction by CD8 T cells is pathogenic in lethal ehrlichiosis by induction of apoptosis/necrosis in hepatocytes. Yet, CD8 T cells, along with CD4 T cells and antibodies, also contribute to protective immunity in ehrlichial infections. In granulocytic anaplasmosis, CD8 T cells impact pathogen control modestly but could contribute to immunopathology by virtue of their dysfunction. While preliminary evidence indicates that CD8 T cells are important in protection against Orientia tsutsugamushi, mechanistic studies have been neglected. Valid animal models will enable experiments to elucidate protective and pathologic immune mechanisms. The public health need for vaccines against these agents of human disease, most clearly O. tsutsugamushi, and the veterinary diseases, canine monocytotropic ehrlichiosis (E. canis), heartwater (E. ruminantium) and bovine anaplasmosis (A. marginale) requires detailed immunity and immunopathology investigations, including the roles of CD8 T lymphocytes. PMID:25823954

  13. Linking morphodynamics and directional persistence of T lymphocyte migration.

    PubMed

    Liu, Xiaji; Welf, Erik S; Haugh, Jason M

    2015-05-01

    T cells play a central role in the adaptive immune response, and their directed migration is essential for homing to sites of antigen presentation. Like neutrophils, T lymphocytes are rapidly moving cells that exhibit amoeboid movement, characterized by a definitive polarity with F-actin concentrated at the front and myosin II elsewhere. In this study, we used total internal reflection fluorescence (TIRF) microscopy to monitor the cells' areas of contact with a surface presenting adhesive ICAM-1 and the chemokine, CXCL12/SDF-1. Our analysis reveals that T-cell migration and reorientation are achieved by bifurcation and lateral separation of protrusions along the leading membrane edge, followed by cessation of one of the protrusions, which acts as a pivot for cell turning. We show that the distribution of bifurcation frequencies exhibits characteristics of a random, spontaneous process; yet, the waiting time between bifurcation events depends on whether or not the pivot point remains on the same side of the migration axis. Our analysis further suggests that switching of the dominant protrusion between the two sides of the migration axis is associated with persistent migration, whereas the opposite is true of cell turning. To help explain the bifurcation phenomenon and how distinct migration behaviours might arise, a spatio-temporal, stochastic model describing F-actin dynamics is offered. PMID:25904526

  14. Cytotoxic T lymphocyte antigen-4 and immune checkpoint blockade.

    PubMed

    Buchbinder, Elizabeth; Hodi, F Stephen

    2015-09-01

    The relationship between cancer and the immune system is complex and provides unique therapeutic opportunities. Cytotoxic T lymphocyte antigen-4 (CTLA-4) is a regulatory molecule that suppresses T cell effector function following initial activation by costimulatory signals. Fully human monoclonal antibodies targeting CTLA-4 have been shown to increase T cell function and antitumor responses in patients with advanced metastatic melanoma. Responses observed with such immune checkpoint therapy can follow a different pattern from that seen with cytotoxic chemotherapy or targeted therapy and may continue after therapy is discontinued. In addition, the toxicities that are associated with anti-CTLA-4 therapy may differ from those of conventional therapies and consist of inflammatory events in parts of the body that do not contain cancerous cells. Early recognition of these inflammatory events and intervention is important, and the identification of predictive biomarkers continues to be an unfulfilled need in the field of immunotherapy. Combinatorial approaches with targeted therapies, radiation therapy, chemotherapy, or other immune checkpoint agonists/antagonists have the potential to increase the efficacy of CTLA-4 blockade. PMID:26325034

  15. Glucocorticoid receptor content of T lymphocytes: evidence for heterogeneity.

    PubMed

    Distelhorst, C W; Benutto, B M

    1981-04-01

    Glucocorticoid receptors were measured in T lymphocytes that were isolated from peripheral blood by either nylon wool filtration or E-rosette sedimentation. T cells isolated by nylon wool filtration specifically bind 6.7 +/- 0.2 fmol of dexamethasone per million cells (equivalent to 4000 +/- 200 receptors per cell), whereas T cells isolated by E-rosette sedimentation bind 12.0 +/- 0.7 fmol of dexamethasone per million cells (equivalent to 7200 +/- 400 receptors per cell). This difference in the amount of dexamethasone bound by the two T cell preparations was significant (p less than .001) and was present immediately after cell isolation. The binding affinities of the different T cell preparations for dexamethasone were similar. T cells that are isolated by a combination of nylon wool filtration followed by E-rosette sedimentation bind the same amount of dexamethasone as T cells isolated by nylon wool filtration alone. T cells isolated by a combination of E-rosette sedimentation following by nylon wool filtration bind less dexamethasone than do T cells isolated by E-rosette sedimentation alone. These findings suggest that T cells are heterogeneous with respect to their quantity of glucocorticoid receptors. Isolation of T cells by E-rosette sedimentation enriches for T cells that have a greater number of glucocorticoid receptors, and isolation of T cells by nylon wool filtration enriches for T cells that have a lesser number of glucocorticoid receptors. PMID:6970782

  16. Protective Role of Cytotoxic T Lymphocytes in Filovirus Hemorrhagic Fever

    PubMed Central

    Warfield, Kelly Lyn; Olinger, Gene Garrard

    2011-01-01

    Infection with many emerging viruses, such as the hemorrhagic fever disease caused by the filoviruses, Marburg (MARV), and Ebola virus (EBOV), leaves the host with a short timeframe in which to mouse a protective immune response. In lethal cases, uncontrolled viral replication and virus-induced immune dysregulation are too severe to overcome, and mortality is generally associated with a lack of notable immune responses. Vaccination studies in animals have demonstrated an association of IgG and neutralizing antibody responses against the protective glycoprotein antigen with survival from lethal challenge. More recently, studies in animal models of filovirus hemorrhagic fever have established that induction of a strong filovirus-specific cytotoxic T lymphocyte (CTL) response can facilitate complete viral clearance. In this review, we describe assays used to discover CTL responses after vaccination or live filovirus infection in both animal models and human clinical trials. Unfortunately, little data regarding CTL responses have been collected from infected human survivors, primarily due to the low frequency of disease and the inability to perform these studies in the field. Advancements in assays and technologies may allow these studies to occur during future outbreaks. PMID:22253531

  17. Early contacts between T lymphocytes and activating surfaces

    NASA Astrophysics Data System (ADS)

    Cretel, E.; Touchard, D.; Benoliel, A. M.; Bongrand, P.; Pierres, A.

    2010-05-01

    Cells continually probe their environment to adapt their behaviour. A current challenge is to determine how they analyse nearby surfaces and how they process information to take decisions. We addressed this problem by monitoring human T lymphocyte attachment to surfaces coated with activating anti-CD3 or control anti-HLA antibodies. Interference reflection microscopy allowed us to monitor cell-to-surface apposition with a few nanometre vertical resolution during the first minutes following contact. We found that (i) when a cell fell on a surface, contact extension was preceded by a lag of several tens of seconds. (ii) During this lag, vertical membrane undulations seemed to generate transient contacts with underlying surfaces. (iii) After the lag period, the contact area started increasing linearly with a rate of about 1.5 µm2 s - 1 on activating surfaces and about 0.2 µm2 s - 1 on control surfaces. (iv) Concomitantly with lateral surface extension, the apparent distance between cell membranes and surfaces steadily decreased. These results are consistent with the hypothesis that the cell decision to spread rapidly on activating surfaces resulted from the integration of information yielded by transient contacts with these surfaces generated by membrane undulations during a period of about 1 min.

  18. T-lymphocyte colonies in the lymphoproliferative disorders.

    PubMed Central

    Dao, C; Marie, J P; Bernadou, A; Bilski-Pasquier, G

    1978-01-01

    Human lymphocytes from peripheral blood, bone marrow spleen and lymph nodes were cultured. Continuous phytoheamagglutinin (PHA) stimulation was used, first during a 24 h liquid preincubation, then during a 5 day culture in methylcellulose. In normal donors a rapid colony formation took place, with a mean of 124+/-82 colonies per 1 times 10(5) preincubated lymphocytes. Cells from such colonies were studied by cytology, scanning electron microscopy and rosette formation techniques; arguments favour the hypothesis that these could be T lymphocytes. Neither granulocytes nor macrophages could be grown, and no lymphoid colony formation occurred without PHA stimulation. The same technique was applied to patients with various lymphoproliferative disorders. Significant colony suppression was observed in nearly every case of chronic lymphatic leukaemia; the number of colonies was reduced in some patients with acute lymphatic leukaemia, lymphosarcoma, dysglobulinaemia and Hodgkin's disease. This lymphoid culture method should be applied to a larger number of patients to determine whether it has a classification value and/or prognostic significance. When colonies were grown in pathological states, rosette formation was identical to that of normal donors; colony formation could be due to persisting normal lymphocytes. Images Figure 2 Figure 3 PMID:309852

  19. 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

  20. Mitogenic signal transduction in T lymphocytes in microgravity

    NASA Technical Reports Server (NTRS)

    Cogoli, A.; Bechler, B.; Cogoli-Greuter, M.; Criswell, S. B.; Joller, H.; Joller, P.; Hunzinger, E.; Muller, O.

    1993-01-01

    The activation by concanavalin A Con A of human peripheral blood lymphocytes (PBLs) in the presence of monocytes as accessory cells was investigated in cultures exposed to microgravity conditions in Spacelab. Activation of T cells was measured as incorporation of [3H]thymidine into DNA, secretion of interleukin-2 (IL-2), and interferon-gamma, and expression of IL-2 receptors. Whereas, as discovered in earlier experiments, the activation of resuspended T cells is strongly inhibited, activation of cells attached to microcarrier beads is more than doubled in microgravity. The results suggest that the depression of the activation in resuspended cells may be attributed to a malfunction of monocytes acting as accessory cells. In fact, although the ultrastructure of resuspended monocytes is not altered in microgravity, the secretion of IL-1 is strongly inhibited. Our data suggest that (1) IL-2 is produced independently of IL-1, (2) IL-1 production is triggered only when monocytes (and lymphocytes?) adhere to microcarriers, (3) the expression of IL-2 receptors depends on IL-1, and (4) provided sufficient IL-1 is available, activation is enhanced in microgravity. Finally, cultures of resuspended PBLs and monocytes in microgravity constitute a complete and natural system in which monocytes are not operational. This may be useful for studies of the role of accessory cells and cell-cell interactions in T lymphocyte activation.

  1. 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.

  2. 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

  3. T lymphocyte line specific for thyroglobulin produces or vaccinates against autoimmune thyroiditis in mice.

    PubMed

    Maron, R; Zerubavel, R; Friedman, A; Cohen, I R

    1983-11-01

    We investigated Ly-1+ T lymphocyte line cells specifically reactive to thyroglobulin (Tg) that were isolated from mice primed with mouse Tg in adjuvant. Intravenous inoculation of as few as 10(5) line cells was sufficient to cause severe and prolonged thyroiditis in recipient mice that were intact, irradiated, or athymic nudes. Disease was independent of circulating Tg antibodies, suggesting that anti-Tg T lymphocytes could cause thyroiditis unaided by antibodies. Thyroiditogenic T lymphocytes could be isolated as cell lines from apparently healthy mice that had been immunized with non-thyroiditogenic bovine Tg in adjuvant, which indicates that autoimmune effector T lymphocytes may develop covertly in the course of immunization with foreign antigens. Finally, a single i.v. inoculation of anti-Tg T lymphocyte line cells attenuated by irradiation vaccinated mice completely against subsequent development of autoimmune thyroiditis produced either by active immunization to Tg or by passive transfer of intact line cells. Vaccinated mice that were protected from inflammatory lesions of thyroiditis still produced high titers of Tg antibodies in response to active immunization. Thus, vaccination specifically inhibited thyroiditogenic T lymphocytes but not helper T lymphocytes required for the production of Tg autoantibodies. PMID:6195260

  4. [Activation of peripheral T lymphocytes in children with epilepsy and production of cytokines].

    PubMed

    Yang, Jie; Hu, Chongkang; Jiang, Xun

    2016-09-01

    Objective To study the state of peripheral T lymphocytes and cytokine levels in children with epilepsy. Methods Twenty children with epilepsy and 20 healthy age-matched children were recruited and their peripheral blood was collected. The activation of T lymphocytes was evaluated by detecting the expressions of CD25, CD69 and cytotoxic T lymphocyte-assicated antigen 4 (CTLA4). The function of T lymphocytes was evaluated by detecting the expressions of interferon γ (IFN-γ), tumor necrosis factor α (TNF-α), IL-17A and IL-6. The activation of regulatory T cells (Tregs) was evaluated by detecting the expression of IL-10. Results Children with epilepsy had higher expressions of CD25, CD69 and CTLA-4 in T lymphocytes than the controls did. The expressions of IFN-γ, TNF-α, IL-17A and IL-6 in T lymphocytes of children with epilepsy were higher than those of the controls. Frequency of Tregs producing IL-10 was higher in children with epilepsy as compared with the controls. Conclusion Peripheral T lymphocytes of children with epilepsy are activated and produce cytokines. PMID:27609580

  5. Curcumin reduces brain-infiltrating T lymphocytes after intracerebral hemorrhage in mice.

    PubMed

    Liu, Wei; Yuan, Jichao; Zhu, Haitao; Zhang, Xuan; Li, Lan; Liao, Xiaojun; Wen, Zexian; Chen, Yaxing; Feng, Hua; Lin, Jiangkai

    2016-05-01

    T lymphocytes contribute to inflammation, thereby exacerbating neuronal injury after cerebral ischemia. An increasing amount of evidence indicates that inflammation is a key contributor to intracerebral hemorrhage (ICH)-induced secondary brain injury. Curcumin, a low-molecular-weight curry spice that is derived from the Curcuma longa plant, suppresses T lymphocyte proliferation and migration. Based on these findings, we investigated whether treatment with curcumin would reduce the number of cerebral T lymphocytes in mice with experimentally induced ICH. We found that a large number of T lymphocytes infiltrated the brain at 3days post-ICH. Curcumin significantly improved neurological scores and reduced brain edema in mice with ICH, consistent with a role in reducing neuroinflammation and neurovascular injury. Using flow cytometry, we observed significantly fewer T lymphocytes in brain samples obtained from the curcumin-treated group than in samples obtained from the vehicle-treated group. Moreover, Western blot analysis and immunostaining indicated that treatment with curcumin significantly reduced the expression of a vascular cell adhesion molecule-1 (VCAM-1), interferon-γ (INF-γ) and interleukin-17 (IL-17) in the mouse brain at 72h post-ICH. Our results suggest that administering curcumin may alleviate cerebral inflammation resulting from ICH, at least in part by reducing the infiltration of T lymphocytes into the brain. Therefore, preventing T lymphocytes from infiltrating the brain may become a new strategy for treating clinical ICH. PMID:27026486

  6. Gedunin, a natural tetranortriterpenoid, modulates T lymphocyte responses and ameliorates allergic inflammation.

    PubMed

    Ferraris, Fausto K; Moret, Katelim Hottz; Figueiredo, Alexandre Bezerra Conde; Penido, Carmen; Henriques, Maria das Graças M O

    2012-09-01

    T lymphocytes are critical cells involved in allergy. Here, we report that the natural tetranortriterpenoid gedunin impaired allergic responses primarily by modulating T lymphocyte functions. The intraperitoneal (i.p.) administration of gedunin inhibited pleural leukocyte accumulation triggered by intra-pleural (i.pl.) challenge with ovalbumin (OVA) in previously sensitized C57BL/6 mice; this inhibition was primarily due to the impairment of eosinophil and T lymphocyte influx. Likewise, i.pl. pre-treatment with gedunin inhibited eosinophil and T lymphocyte migration into mouse lungs 24 h after OVA intra-nasal (i.n.) instillation. Pre-treatment with gedunin diminished the levels of CCL2, CCL3, CCL5, CCL11, Interleukin-5 and leukotriene B(4) at the allergic site. In vitro pre-treatment with gedunin failed to inhibit T lymphocyte adhesion and chemotaxis towards pleural washes recovered from OVA-challenged mice, suggesting that gedunin inhibits T lymphocyte migration in vivo via the inhibition of chemotactic mediators in situ. In vivo pre-treatment with gedunin reduced the numbers of CD69(+) and CD25(+) T lymphocytes in the pleura and CD25(+) cells in the thoracic lymph nodes 24 h after OVA i.pl. challenge. In accordance, in vitro treatment of T lymphocytes with gedunin inhibited α-CD3 mAb-induced expression of CD69 and CD25, proliferation, Interleukin-2 production and nuclear translocation of NFκB and NFAT. Notably, post-treatment of mice with gedunin reverted OVA-induced lung allergic inflammation by decreasing the T lymphocyte and eosinophil counts and the levels of eosinophilotactic mediators in bronchoalveolar lavage fluid. Our results demonstrate a remarkable anti-allergic effect of gedunin due to its capability to modulate T cell activation and trafficking into the airways. PMID:22709475

  7. Forging T-Lymphocyte Identity: Intersecting Networks of Transcriptional Control.

    PubMed

    Rothenberg, Ellen V; Ungerbäck, Jonas; Champhekar, Ameya

    2016-01-01

    T-lymphocyte development branches off from other lymphoid developmental programs through its requirement for sustained environmental signals through the Notch pathway. In the thymus, Notch signaling induces a succession of T-lineage regulatory factors that collectively create the T-cell identity through distinct steps. This process involves both the staged activation of T-cell identity genes and the staged repression of progenitor-cell-inherited regulatory genes once their roles in self-renewal and population expansion are no longer needed. With the recent characterization of innate lymphoid cells (ILCs) that share transcriptional regulation programs extensively with T-cell subsets, T-cell identity can increasingly be seen as defined in modular terms, as the processes selecting and actuating effector function are potentially detachable from the processes generating and selecting clonally unique T-cell receptor structures. The developmental pathways of different classes of T cells and ILCs are distinguished by the numbers of prerequisites of gene rearrangement, selection, and antigen contact before the cells gain access to nearly common regulatory mechanisms for choosing effector function. Here, the major classes of transcription factors that interact with Notch signals during T-lineage specification are discussed in terms of their roles in these programs, the evidence for their spectra of target genes at different stages, and their cross-regulatory and cooperative actions with each other. Specific topics include Notch modulation of PU.1 and GATA-3, PU.1-Notch competition, the relationship between PU.1 and GATA-3, and the roles of E proteins, Bcl11b, and GATA-3 in guiding acquisition of T-cell identity while avoiding redirection to an ILC fate. PMID:26791859

  8. Altered T Lymphocyte Proliferation upon Lipopolysaccharide Challenge Ex Vivo

    PubMed Central

    Poujol, Fanny; Monneret, Guillaume; Pachot, Alexandre; Textoris, Julien; Venet, Fabienne

    2015-01-01

    Context Sepsis is characterized by the development of adaptive immune cell alterations, which intensity and duration are associated with increased risk of health-care associated infections and mortality. However, pathophysiological mechanisms leading to such lymphocyte dysfunctions are not completely understood, although both intrinsic lymphocyte alterations and antigen-presenting cells (APCs) dysfunctions are most likely involved. Study The aim of the current study was to evaluate whether lipopolysaccharide (LPS, mimicking initial Gram negative bacterial challenge) could directly impact lymphocyte function after sepsis. Therefore, we explored ex-vivo the effect of LPS priming on human T lymphocyte proliferation induced by different stimuli. Results We showed that LPS priming of PBMCs reduced T cell proliferative response and altered IFNγ secretion after stimulation with OKT3 but not with phytohaemagglutinin or anti-CD2/CD3/CD28-coated beads stimulations. Interestingly only LPS priming of monocytes led to decreased T cell proliferative response as opposed to LPS priming of lymphocytes. Importantly, LPS priming was associated with reduced expression of HLA-DR, CD86 and CD64 on monocytes but not with the modification of CD3, CTLA4, PD-1 and CD28 expressions on lymphocytes. Finally, IFNγ stimulation restored monocytes accessory functions and T cell proliferative response to OKT3. Conclusion We conclude that LPS priming does not directly impact lymphocyte functions but reduces APC’s capacity to activate T cells. This recapitulates ex vivo indirect mechanisms participating in sepsis-induced lymphocyte alterations and suggests that monocyte-targeting immunoadjuvant therapies in sepsis may also help to improve adaptive immune dysfunctions. Direct mechanisms impacting lymphocytes being also at play during sepsis, the respective parts of direct versus indirect sepsis-induced lymphocyte alterations remain to be evaluated in clinic. PMID:26642057

  9. Calcium signals in T lymphocytes from old mice.

    PubMed

    Miller, R A

    1996-01-01

    Mitogen-induced increases in free calcium ion concentration ([Ca]i) are a key element of the process by which T lymphocytes are induced to proliferate and differentiate into effector cells. T cells from old mice exhibit lower average rises in calcium concentration than T cells from young donors when stimulated with either mitogenic lectins or antibodies to the CD3 chains of the antigen receptor. The decline with age in calcium signal generation is largely attributable to a shift from naïve to memory T cells, in that memory T cells, from mice of any age, are more resistant to mitogen-induced changes in [Ca]i. The decline in calcium signal generation is likely to be functionally significant, since T cells isolated on the basis of poor calcium signals show diminished ability to produce and to respond to the growth factor IL-2. Con A induces a transient increase in uptake of radiolabeled calcium from extracellular sources, and the extent of this increase declines with age. Alterations in production of inositol tris-phosphate (IP3) seem not to contribute to age-related changes in calcium signal generation. T cells from old mice, and memory T cells from mice of any age, are relatively resistant to increases in [Ca]i even when these are induced by receptor-independent stimuli such as the calcium ionophore ionomycin. The ionomycin-resistance of memory T cells suggests that these cells may have an augmented ability to buffer changes in [Ca]i, perhaps by increased activity of the ATP-dependent plasma membrane calcium pump. It seems likely that age-related declines in calcium signal generation contribute to the functional immunodeficiency of old age. PMID:8761335

  10. Spaceflight effects on T lymphocyte distribution, function and gene expression

    PubMed Central

    Gridley, Daila S.; Slater, James M.; Luo-Owen, Xian; Rizvi, Asma; Chapes, Stephen K.; Stodieck, Louis S.; Ferguson, Virginia L.; Pecaut, Michael J.

    2009-01-01

    The immune system is highly sensitive to stressors present during spaceflight. The major emphasis of this study was on the T lymphocytes in C57BL/6NTac mice after return from a 13-day space shuttle mission (STS-118). Spleens and thymuses from flight animals (FLT) and ground controls similarly housed in animal enclosure modules (AEM) were evaluated within 3–6 h after landing. Phytohemagglutinin-induced splenocyte DNA synthesis was significantly reduced in FLT mice when based on both counts per minute and stimulation indexes (P < 0.05). Flow cytometry showed that CD3+ T and CD19+ B cell counts were low in spleens from the FLT group, whereas the number of NK1.1+ natural killer (NK) cells was increased (P < 0.01 for all three populations vs. AEM). The numerical changes resulted in a low percentage of T cells and high percentage of NK cells in FLT animals (P < 0.05). After activation of spleen cells with anti-CD3 monoclonal antibody, interleukin-2 (IL-2) was decreased, but IL-10, interferon-γ, and macrophage inflammatory protein-1α were increased in FLT mice (P < 0.05). Analysis of cancer-related genes in the thymus showed that the expression of 30 of 84 genes was significantly affected by flight (P < 0.05). Genes that differed from AEM controls by at least 1.5-fold were Birc5, Figf, Grb2, and Tert (upregulated) and Fos, Ifnb1, Itgb3, Mmp9, Myc, Pdgfb, S100a4, Thbs, and Tnf (downregulated). Collectively, the data show that T cell distribution, function, and gene expression are significantly modified shortly after return from the spaceflight environment. PMID:18988762

  11. Chemokines and T lymphocyte recruitment to lymph nodes in HIV infection.

    PubMed Central

    Tedla, N.; Palladinetti, P.; Kelly, M.; Kumar, R. K.; DiGirolamo, N.; Chattophadhay, U.; Cooke, B.; Truskett, P.; Dwyer, J.; Wakefield, D.; Lloyd, A.

    1996-01-01

    Recruitment of T lymphocytes to lymph nodes in patients with HIV infection is critical to the pathogenesis of disease. Chemokines are a family of cytokines, which are potent regulators of leukocyte migration. We studied the leukocyte populations and expression of chemokines known to be active upon T cells in lymph nodes of four HIV infected patients and seven control subjects using in situ hybridization, immunohistochemistry, and FACS analysis. The HIV lymph nodes showed CD8+ T lymphocyte accumulation and strongly enhanced chemokine expression, notably for the CD8+ T cell chemoattractant, macrophage inflammatory protein (MIP)-1 alpha. Resident macrophages appeared to be a major cellular source of chemokines in the HIV nodes. RANTES expression was present in both HIV and control lymph nodes, suggesting a physiological role for this chemokine in T lymphocyte recirculation. Chemokines may be important determinants of T lymphocyte accumulation in lymphoid tissue of patients with HIV/AIDS. Images Figure 1 Figure 2 PMID:8623908

  12. Cytotoxic T lymphocytes as a potential brake of keratinocyte proliferation in psoriasis.

    PubMed

    Vičić, Marijana; Peternel, Sandra; Simonić, Edita; Sotošek-Tokmadžić, Vlatka; Massari, Dražen; Brajac, Ines; Kaštelan, Marija; Prpić-Massari, Larisa

    2016-02-01

    Psoriasis is a chronic papulosquamous skin disease, histologically characterized by epidermal hyperproliferation and dermal infiltration of inflammatory cells. The majority of T lymphocytes infiltrating dermis are CD4+ T lymphocytes secreting type 1 and type 17 cytokines. These cytokines are responsible for triggering keratinocyte proliferation as well as chemokine secretion and subsequent migration of other inflammatory cells in the skin. Contrarily, lymphocytes that accumulate in epidermis are mainly CD8+ T lymphocytes. According to the recent findings, these cells can also secrete type 1 and type 17 cytokines. However, it is demonstrated so far that epidermal CD8+ T lymphocytes contain higher amounts of cytolytic molecules, such as perforin, granzyme B and granulysin whose role in psoriasis pathogenesis is still unknown. Therefore, in this article we hypothesize the active involvement of cell mediated cytotoxicity in killing the proliferating keratinocytes as a mechanism of potential self-defense and possible brake in psoriatic plaque formation, maintaining skin homeostasis. PMID:26826643

  13. The Microtubule-Associated Protein Lis1 Regulates T Lymphocyte Homeostasis and Differentiation.

    PubMed

    Ngoi, Soo M; Lopez, Justine M; Chang, John T

    2016-05-15

    The microtubule-associated protein lissencephaly 1 (Lis1) is a key regulator of cell division during stem cell renewal and differentiation. In this study, we examined the role of Lis1 in T lymphocyte homeostasis and fate diversification in response to microbial infection. T cell-specific deletion of Lis1 resulted in depletion of the peripheral CD4(+) and CD8(+) T lymphocyte pool owing to a loss of homeostatic, cytokine-induced proliferation. In contrast, cognate Ag-triggered proliferation was much less affected, enabling Lis1-deficient CD8(+) T cells to differentiate into terminal effector cells in response to microbial infection. Strikingly, however, the specification of Lis1-deficient long-lived memory CD8(+) T lymphocytes was impaired due, in part, to an apparent failure to differentiate appropriately to IL-15. Taken together, these findings suggest that Lis1 plays an important role in T cell homeostasis and the generation of memory T lymphocytes. PMID:27029586

  14. Mechanisms of T-lymphocyte accumulation during experimental pleural infection induced by Mycobacterium bovis BCG.

    PubMed

    Souza, Mariana C; Penido, Carmen; Costa, Maria F S; Henriques, Maria Graças

    2008-12-01

    Tuberculous pleurisy is a frequent extrapulmonary manifestation characterized by accumulation of fluid and inflammatory cells in the pleural space. Here, we investigated the mechanisms of T-lymphocyte accumulation in the pleural space by using a murine model of pleurisy induced by Mycobacterium bovis BCG. Intrathoracic (i.t.) injection of BCG (4.5 x 10(5) bacteria/cavity) induced accumulation of T lymphocytes in the pleural cavities of C57BL/6 mice. We observed the presence of CFU in pleural washes conducted 1, 2, 3, 7, and 15 days after pleurisy induction. Pretreatment with fucoidan inhibited T-lymphocyte accumulation at 1 day, but not at 15 days, after BCG-induced pleurisy. Accordingly, adoptive transfer of fluorescein isothiocyanate-labeled blood mononuclear cells to infected mice showed that T lymphocytes migrated into the pleural cavity 1 day (but not 15 days) after BCG injection. Cell-free pleural wash fluids recovered from mice 1 day after BCG i.t. stimulation (day 1 BCG-PW), but not day 7 or day 15 BCG-PW, induced in vitro T-cell transmigration, which was dependent on L-, P-, and E-selectins. In contrast, day 7 BCG-PW (but not day 1 BCG-PW) induced in vitro T-lymphocyte proliferation via interleukin-2 (IL-2) and gamma interferon (IFN-gamma). Accordingly, in vivo IL-2 or IFN-gamma neutralization abolished T-lymphocyte accumulation 7 days after pleurisy induction. Our results demonstrate that pleural infection induced by BCG leads to T-lymphocyte accumulation in two waves. The acute phase depends on selectin-mediated migration, while the second wave of T-lymphocyte accumulation seems to depend on a local proliferation induced by cytokines produced in situ. PMID:18809659

  15. Phenotypic and functional consequences of herpesvirus saimiri infection of human CD8+ cytotoxic T lymphocytes.

    PubMed Central

    Berend, K R; Jung, J U; Boyle, T J; DiMaio, J M; Mungal, S A; Desrosiers, R C; Lyerly, H K

    1993-01-01

    Herpesvirus saimiri (HVS) was used to infect and transform human CD8+ cytotoxic T lymphocytes (CTL), and the phenotypic and functional consequences of HVS infection of CD8+ T lymphocytes were investigated. HVS-transformed CTL no longer require antigen restimulation yet maintain their phenotype and HLA-restricted cytolytic function and specificity. The ability of HVS to transform CTL may have an important role in the functional analysis of human antigen-specific CTL. Images PMID:8396687

  16. The influence of aminophylline on the nanostructure and nanomechanics of T lymphocytes: an AFM study

    PubMed Central

    2014-01-01

    Although much progress has been made in the illustration of the mechanism of aminophylline (AM) treating asthma, there is no data about its effect on the nanostructure and nanomechanics of T lymphocytes. Here, we presented atomic force spectroscopy (AFM)-based investigations at the nanoscale level to address the above fundamental biophysical questions. As increasing AM treatment time, T lymphocytes' volume nearly double increased and then decreased. The changes of nanostructural features of the cell membrane, i.e., mean height of particles, root-mean-square roughness (Rq), crack and fragment appearance, increased with AM treatment time. T lymphocytes were completely destroyed with 96-h treatment, and they existed in the form of small fragments. Analysis of force-distance curves showed that the adhesion force of cell surface decreased significantly with the increase of AM treatment time, while the cell stiffness increased firstly and then decreased. These changes were closely correlated to the characteristics and process of cell oncosis. In total, these quantitative and qualitative changes of T lymphocytes' structure and nanomechanical properties suggested that AM could induce T lymphocyte oncosis to exert anti-inflammatory effects for treating asthma. These findings provide new insights into the T lymphocyte oncosis and the anti-inflammatory mechanism and immune regulation actions of AM. PMID:25258618

  17. Pharmacological advantages of melatonin in immunosenescence by improving activity of T lymphocytes

    PubMed Central

    Yoo, Yeong-Min; Jang, Su Kil; Kim, Gwang-Hoon; Park, Jung-Youl; Joo, Seong-Soo

    2016-01-01

    Abstract Melatonin plays a critical role in regulating photoperiodic signals and has recently been shown to decrease immunosenescence with age. In this study, we examined whether melatonin activates T lymphocytes as major adaptive immune cells in in vitro and in vivo models. Splenocytes, CD4+, and naïve CD4 T lymphocytes were isolated from the spleen of BALB/c mice and the cell population patterns and mRNA profiles associated with T cell activation (CD28 and p21) and the melatonin receptor (MT1A and MT1B) were assessed. The T cell activation-related proteins Ki67 and Bcl2 were also evaluated to confirm the relationship between gene and protein levels. Our data clearly revealed that CD28, p21, MT1A, and MT1B mRNA were highly expressed in the presence of melatonin. Co-culture of CD4+ T lymphocyte and peritoneal macrophage 7 days after melatonin administration to young and aged mice significantly increased APRIL mRNA, suggesting induction or maintenance of T lymphocyte responses. We also found that the intracellular amount of Ki67 and Bcl2 proteins were significantly upregulated in aged CD4+ T lymphocytes, suggesting enhancing T cell proliferation and ling-term maintenance of memory T cells. Taken together, we conclude that melatonin supplementation may enhance immunity in aged individuals by upregulating immunosenescence indices in association with T lymphocytes and may be an attractive pharmacological candidate for aged and immunocompromised individuals.

  18. Piperine from black pepper inhibits activation-induced proliferation and effector function of T lymphocytes.

    PubMed

    Doucette, Carolyn D; Rodgers, Gemma; Liwski, Robert S; Hoskin, David W

    2015-11-01

    Piperine is a major alkaloid component of black pepper (Piper nigrum Linn), which is a widely consumed spice. Here, we investigated the effect of piperine on mouse T lymphocyte activation. Piperine inhibited polyclonal and antigen-specific T lymphocyte proliferation without affecting cell viability. Piperine also suppressed T lymphocyte entry into the S and G2 /M phases of the cell cycle, and decreased expression of G1 -associated cyclin D3, CDK4, and CDK6. In addition, piperine inhibited CD25 expression, synthesis of interferon-γ, interleukin (IL)-2, IL-4, and IL-17A, and the generation of cytotoxic effector cells. The inhibitory effect of piperine on T lymphocytes was associated with hypophosphorylation of Akt, extracellular signal-regulated kinase, and inhibitor of κBα, but not ZAP-70. The ability of piperine to inhibit several key signaling pathways involved in T lymphocyte activation and the acquisition of effector function suggests that piperine might be useful in the management of T lymphocyte-mediated autoimmune and chronic inflammatory disorders. PMID:25900378

  19. The influence of aminophylline on the nanostructure and nanomechanics of T lymphocytes: an AFM study

    NASA Astrophysics Data System (ADS)

    Huang, Xun; He, Jiexiang; Liu, Mingxian; Zhou, Changren

    2014-09-01

    Although much progress has been made in the illustration of the mechanism of aminophylline (AM) treating asthma, there is no data about its effect on the nanostructure and nanomechanics of T lymphocytes. Here, we presented atomic force spectroscopy (AFM)-based investigations at the nanoscale level to address the above fundamental biophysical questions. As increasing AM treatment time, T lymphocytes' volume nearly double increased and then decreased. The changes of nanostructural features of the cell membrane, i.e., mean height of particles, root-mean-square roughness (Rq), crack and fragment appearance, increased with AM treatment time. T lymphocytes were completely destroyed with 96-h treatment, and they existed in the form of small fragments. Analysis of force-distance curves showed that the adhesion force of cell surface decreased significantly with the increase of AM treatment time, while the cell stiffness increased firstly and then decreased. These changes were closely correlated to the characteristics and process of cell oncosis. In total, these quantitative and qualitative changes of T lymphocytes' structure and nanomechanical properties suggested that AM could induce T lymphocyte oncosis to exert anti-inflammatory effects for treating asthma. These findings provide new insights into the T lymphocyte oncosis and the anti-inflammatory mechanism and immune regulation actions of AM.

  20. HIV-1 Nef interferes with T-lymphocyte circulation through confined environments in vivo

    PubMed Central

    Stolp, Bettina; Imle, Andrea; Coelho, Fernanda Matos; Hons, Miroslav; Gorina, Roser; Lyck, Ruth; Stein, Jens V.; Fackler, Oliver T.

    2012-01-01

    HIV-1 negative factor (Nef) elevates virus replication and contributes to immune evasion in vivo. As one of its established in vitro activities, Nef interferes with T-lymphocyte chemotaxis by reducing host cell actin dynamics. To explore Nef’s influence on in vivo recirculation of T lymphocytes, we assessed lymph-node homing of Nef-expressing primary murine lymphocytes and found a drastic impairment in homing to peripheral lymph nodes. Intravital imaging and 3D immunofluorescence reconstruction of lymph nodes revealed that Nef potently impaired T-lymphocyte extravasation through high endothelial venules and reduced subsequent parenchymal motility. Ex vivo analyses of transendothelial migration revealed that Nef disrupted T-lymphocyte polarization and interfered with diapedesis and migration in the narrow subendothelial space. Consistently, Nef specifically affected T-lymphocyte motility modes used in dense environments that pose high physical barriers to migration. Mechanistically, inhibition of lymph node homing, subendothelial migration and cell polarization, but not diapedesis, depended on Nef’s ability to inhibit host cell actin remodeling. Nef-mediated interference with in vivo recirculation of T lymphocytes may compromise T-cell help and thus represents an important mechanism for its function as a HIV pathogenicity factor. PMID:23093676

  1. Vaccine-elicited memory cytotoxic T lymphocytes contribute to Mamu-A*01-associated control of simian/human immunodeficiency virus 89.6P replication in rhesus monkeys.

    PubMed

    Seaman, Michael S; Santra, Sampa; Newberg, Michael H; Philippon, Valerie; Manson, Kelledy; Xu, Ling; Gelman, Rebecca S; Panicali, Dennis; Mascola, John R; Nabel, Gary J; Letvin, Norman L

    2005-04-01

    The expression of particular major histocompatibility complex (MHC) class I alleles can influence the rate of disease progression following lentiviral infections. This effect is a presumed consequence of potent cytotoxic T-lymphocyte (CTL) responses that are restricted by these MHC class I molecules. The present studies have examined the impact of the MHC class I allele Mamu-A*01 on simian/human immunodeficiency virus 89.6P (SHIV-89.6P) infection in unvaccinated and vaccinated rhesus monkeys by exploring the contribution of dominant-epitope specific CTL in this setting. Expression of Mamu-A*01 in immunologically naive monkeys was not associated with improved control of viral replication, CD4+ T-lymphocyte loss, or survival. In contrast, Mamu-A*01+ monkeys that had received heterologous prime/boost immunizations prior to challenge maintained higher CD4+ T-lymphocyte levels and better control of SHIV-89.6P replication than Mamu-A*01- monkeys. This protection was associated with the evolution of high-frequency anamnestic CTL responses specific for a dominant Mamu-A*01-restricted Gag epitope following infection. These data indicate that specific MHC class I alleles can confer protection in the setting of a pathogenic SHIV infection by their ability to elicit memory CTL following vaccination. PMID:15795244

  2. T Lymphocyte Migration: An Action Movie Starring the Actin and Associated Actors.

    PubMed

    Dupré, Loïc; Houmadi, Raïssa; Tang, Catherine; Rey-Barroso, Javier

    2015-01-01

    The actin cytoskeleton is composed of a dynamic filament meshwork that builds the architecture of the cell to sustain its fundamental properties. This physical structure is characterized by a continuous remodeling, which allows cells to accomplish complex motility steps such as directed migration, crossing of biological barriers, and interaction with other cells. T lymphocytes excel in these motility steps to ensure their immune surveillance duties. In particular, actin cytoskeleton remodeling is a key to facilitate the journey of T lymphocytes through distinct tissue environments and to tune their stop and go behavior during the scanning of antigen-presenting cells. The molecular mechanisms controlling actin cytoskeleton remodeling during T lymphocyte motility have been only partially unraveled, since the function of many actin regulators has not yet been assessed in these cells. Our review aims to integrate the current knowledge into a comprehensive picture of how the actin cytoskeleton drives T lymphocyte migration. We will present the molecular actors that control actin cytoskeleton remodeling, as well as their role in the different T lymphocyte motile steps. We will also highlight which challenges remain to be addressed experimentally and which approaches appear promising to tackle them. PMID:26635800

  3. Arctigenin from Arctium lappa inhibits interleukin-2 and interferon gene expression in primary human T lymphocytes

    PubMed Central

    2011-01-01

    Background Arctium lappa (Niubang), a Chinese herbal medicine, is used to treat tissue inflammation. This study investigates the effects of arctigenin (AC), isolated from A. lappa, on anti-CD3/CD28 Ab-stimulated cell proliferation and cytokine gene expression in primary human T lymphocytes. Methods Cell proliferation was determined with enzyme immunoassays and the tritiated thymidine uptake method. Cytokine production and gene expression were analyzed with reverse transcription-polymerase chain reaction. Results AC inhibited primary human T lymphocytes proliferation activated by anti-CD3/CD28 Ab. Cell viability test indicated that the inhibitory effects of AC on primary human T lymphocyte proliferation were not due to direct cytotoxicity. AC suppressed interleukin-2 (IL-2) and interferon-γ (IFN-γ) production in a concentration-dependent manner. Furthermore, AC decreased the IL-2 and IFN-γ gene expression in primary human T lymphocytes induced by anti-CD3/CD28 Ab. Reporter gene analyses revealed that AC decreased NF-AT-mediated reporter gene expression. Conclusion AC inhibited T lymphocyte proliferation and decreased the gene expression of IL-2, IFN-γ and NF-AT. PMID:21435270

  4. T Lymphocyte Migration: An Action Movie Starring the Actin and Associated Actors

    PubMed Central

    Dupré, Loïc; Houmadi, Raïssa; Tang, Catherine; Rey-Barroso, Javier

    2015-01-01

    The actin cytoskeleton is composed of a dynamic filament meshwork that builds the architecture of the cell to sustain its fundamental properties. This physical structure is characterized by a continuous remodeling, which allows cells to accomplish complex motility steps such as directed migration, crossing of biological barriers, and interaction with other cells. T lymphocytes excel in these motility steps to ensure their immune surveillance duties. In particular, actin cytoskeleton remodeling is a key to facilitate the journey of T lymphocytes through distinct tissue environments and to tune their stop and go behavior during the scanning of antigen-presenting cells. The molecular mechanisms controlling actin cytoskeleton remodeling during T lymphocyte motility have been only partially unraveled, since the function of many actin regulators has not yet been assessed in these cells. Our review aims to integrate the current knowledge into a comprehensive picture of how the actin cytoskeleton drives T lymphocyte migration. We will present the molecular actors that control actin cytoskeleton remodeling, as well as their role in the different T lymphocyte motile steps. We will also highlight which challenges remain to be addressed experimentally and which approaches appear promising to tackle them. PMID:26635800

  5. Genetic modification of human T lymphocytes for the treatment of hematologic malignancies

    PubMed Central

    Hoyos, Valentina; Savoldo, Barbara; Dotti, Gianpietro

    2012-01-01

    Modern chemotherapy regimens and supportive care have produced remarkable improvements in the overall survival of patients with hematologic malignancies. However, the development of targeted small molecules, monoclonal antibodies, and biological therapies that demonstrate greater efficacy and lower toxicity remains highly desirable in hematology, and oncology in general. In the context of biological therapies, T-lymphocyte based treatments have enormous potential. Donor lymphocyte infusion in patients relapsed after allogeneic hematopoietic stem cell transplant pioneered the concept that T lymphocytes can effectively control tumor growth, and this was then followed by the development of cell culture strategies to generate T lymphocytes with selective activity against tumor cells. Over the past decade, it has become clear that the adoptive transfer of ex vivo expanded antigen-specific cytotoxic T lymphocytes promotes sustained antitumor effects in patients with virus-associated lymphomas, such as Epstein-Barr virus related post-transplant lymphomas and Hodgkin's lymphomas. Because of this compelling clinical evidence and the concomitant development of methodologies for robust gene transfer to human T lymphocytes, the field has rapidly evolved, offering new opportunities to extend T-cell based therapies. This review summarizes the most recent biological and clinical developments using genetically manipulated T cells for the treatment of hematologic malignancies. PMID:22929977

  6. Emerging Roles of L-Type Voltage-Gated and Other Calcium Channels in T Lymphocytes

    PubMed Central

    Badou, Abdallah; Jha, Mithilesh K.; Matza, Didi; Flavell, Richard A.

    2013-01-01

    In T lymphocytes, calcium ion controls a variety of biological processes including development, survival, proliferation, and effector functions. These distinct and specific roles are regulated by different calcium signals, which are generated by various plasma membrane calcium channels. The repertoire of calcium-conducting proteins in T lymphocytes includes store-operated CRAC channels, transient receptor potential channels, P2X channels, and L-type voltage-gated calcium (Cav1) channels. In this paper, we will focus mainly on the role of the Cav1 channels found expressed by T lymphocytes, where these channels appear to operate in a T cell receptor stimulation-dependent and voltage sensor independent manner. We will review their expression profile at various differentiation stages of CD4 and CD8 T lymphocytes. Then, we will present crucial genetic evidence in favor of a role of these Cav1 channels and related regulatory proteins in both CD4 and CD8 T cell functions such as proliferation, survival, cytokine production, and cytolysis. Finally, we will provide evidence and speculate on how these voltage-gated channels might function in the T lymphocyte, a non-excitable cell. PMID:24009608

  7. NAFLD causes selective CD4(+) T lymphocyte loss and promotes hepatocarcinogenesis.

    PubMed

    Ma, Chi; Kesarwala, Aparna H; Eggert, Tobias; Medina-Echeverz, José; Kleiner, David E; Jin, Ping; Stroncek, David F; Terabe, Masaki; Kapoor, Veena; ElGindi, Mei; Han, Miaojun; Thornton, Angela M; Zhang, Haibo; Egger, Michèle; Luo, Ji; Felsher, Dean W; McVicar, Daniel W; Weber, Achim; Heikenwalder, Mathias; Greten, Tim F

    2016-03-10

    Hepatocellular carcinoma (HCC) is the second most common cause of cancer-related death. Non-alcoholic fatty liver disease (NAFLD) affects a large proportion of the US population and is considered to be a metabolic predisposition to liver cancer. However, the role of adaptive immune responses in NAFLD-promoted HCC is largely unknown. Here we show, in mouse models and human samples, that dysregulation of lipid metabolism in NAFLD causes a selective loss of intrahepatic CD4(+) but not CD8(+) T lymphocytes, leading to accelerated hepatocarcinogenesis. We also demonstrate that CD4(+) T lymphocytes have greater mitochondrial mass than CD8(+) T lymphocytes and generate higher levels of mitochondrially derived reactive oxygen species (ROS). Disruption of mitochondrial function by linoleic acid, a fatty acid accumulated in NAFLD, causes more oxidative damage than other free fatty acids such as palmitic acid, and mediates selective loss of intrahepatic CD4(+) T lymphocytes. In vivo blockade of ROS reversed NAFLD-induced hepatic CD4(+) T lymphocyte decrease and delayed NAFLD-promoted HCC. Our results provide an unexpected link between lipid dysregulation and impaired anti-tumour surveillance. PMID:26934227

  8. Mutant Huntingtin Does Not Affect the Intrinsic Phenotype of Human Huntington’s Disease T Lymphocytes

    PubMed Central

    Miller, James R. C.; Träger, Ulrike; Andre, Ralph; Tabrizi, Sarah J.

    2015-01-01

    Huntington’s disease is a fatal neurodegenerative condition caused by a CAG repeat expansion in the huntingtin gene. The peripheral innate immune system is dysregulated in Huntington’s disease and may contribute to its pathogenesis. However, it is not clear whether or to what extent the adaptive immune system is also involved. Here, we carry out the first comprehensive investigation of human ex vivo T lymphocytes in Huntington’s disease, focusing on the frequency of a range of T lymphocyte subsets, as well as analysis of proliferation, cytokine production and gene transcription. In contrast to the innate immune system, the intrinsic phenotype of T lymphocytes does not appear to be affected by the presence of mutant huntingtin, with Huntington’s disease T lymphocytes exhibiting no significant functional differences compared to control cells. The transcriptional profile of T lymphocytes also does not appear to be significantly affected, suggesting that peripheral immune dysfunction in Huntington’s disease is likely to be mediated primarily by the innate rather than the adaptive immune system. This study increases our understanding of the effects of Huntington’s disease on peripheral tissues, while further demonstrating the differential effects of the mutant protein on different but related cell types. Finally, this study suggests that the potential use of novel therapeutics aimed at modulating the Huntington’s disease innate immune system should not be extended to include the adaptive immune system. PMID:26529236

  9. The Importance of the Nurse Cells and Regulatory Cells in the Control of T Lymphocyte Responses

    PubMed Central

    Reyes García, María Guadalupe; García Tamayo, Fernando

    2013-01-01

    T lymphocytes from the immune system are bone marrow-derived cells whose development and activities are carefully supervised by two sets of accessory cells. In the thymus, the immature young T lymphocytes are engulfed by epithelial “nurse cells” and retained in vacuoles, where most of them (95%) are negatively selected and removed when they have an incomplete development or express high affinity autoreactive receptors. The mature T lymphocytes that survive to this selection process leave the thymus and are controlled in the periphery by another subpopulation of accessory cells called “regulatory cells,” which reduce any excessive immune response and the risk of collateral injuries to healthy tissues. By different times and procedures, nurse cells and regulatory cells control both the development and the functions of T lymphocyte subpopulations. Disorders in the T lymphocytes development and migration have been observed in some parasitic diseases, which disrupt the thymic microenvironment of nurse cells. In other cases, parasites stimulate rather than depress the functions of regulatory T cells decreasing T-mediated host damages. This paper is a short review regarding some features of these accessory cells and their main interactions with T immature and mature lymphocytes. The modulatory role that neurotransmitters and hormones play in these interactions is also revised. PMID:23509712

  10. Possible role of L-selectin in T lymphocyte alveolitis in patients with active pulmonary sarcoidosis.

    PubMed

    Kaseda, M; Kadota, J; Mukae, H; Kawamoto, S; Shukuwa, T; Iwashita, T; Matsubara, Y; Ishimatsu, Y; Yoshinaga, M; Abe, K; Kohno, S

    2000-07-01

    A number of adhesion molecules participate in the recruitment of inflammatory cells to the site of inflammation, and selectins together with their ligands are important in the early transient adhesion phase. In this study, we evaluated the role of L-selectin in T lymphocyte alveolitis in patients with active pulmonary sarcoidosis. We measured serum and bronchoalveolar lavage fluid (BALF) concentrations of soluble (s)L-selectin using an ELISA. Serum and BALF concentrations of sL-selectin were significantly elevated in patients with sarcoidosis compared with control healthy subjects and idiopathic pulmonary fibrosis (IPF) patients (P < 0.05 and P < 0. 01, respectively). The lymphocyte surface marker was also examined in peripheral blood and BALF by flow cytometric analysis. The percentage of CD3+CD62L+ cells (L-selectin-bearing T lymphocytes) was significantly lower in peripheral blood of sarcoidosis than in that of healthy subjects (P < 0.01). In contrast, the percentage of CD3+CD62L- cells (L-selectin-negative T lymphocytes) in BALF of patients with sarcoidosis was significantly higher than in healthy subjects (P < 0.05) and IPF patients (P < 0.01). Furthermore, there was a significant correlation between serum concentrations of sL-selectin and the number of L-selectin-negative T lymphocytes in BALF (r = 0.535, P < 0.01). Our results suggest that L-selectin may be involved in T lymphocyte alveolitis in patients with active pulmonary sarcoidosis. PMID:10886252

  11. Possible role of l-selectin in T lymphocyte alveolitis in patients with active pulmonary sarcoidosis

    PubMed Central

    Kaseda, M; Kadota, J; Mukae, H; Kawamoto, S; Shukuwa, T; Iwashita, T; Matsubara, Y; Ishimatsu, Y; Yoshinaga, M; Abe, K; Kohno, S

    2000-01-01

    A number of adhesion molecules participate in the recruitment of inflammatory cells to the site of inflammation, and selectins together with their ligands are important in the early transient adhesion phase. In this study, we evaluated the role of l-selectin in T lymphocyte alveolitis in patients with active pulmonary sarcoidosis. We measured serum and bronchoalveolar lavage fluid (BALF) concentrations of soluble (s)l-selectin using an ELISA. Serum and BALF concentrations of sl-selectin were significantly elevated in patients with sarcoidosis compared with control healthy subjects and idiopathic pulmonary fibrosis (IPF) patients (P < 0·05 and P < 0·01, respectively). The lymphocyte surface marker was also examined in peripheral blood and BALF by flow cytometric analysis. The percentage of CD3+CD62L+ cells (l-selectin-bearing T lymphocytes) was significantly lower in peripheral blood of sarcoidosis than in that of healthy subjects (P < 0·01). In contrast, the percentage of CD3+CD62L− cells (l-selectin-negative T lymphocytes) in BALF of patients with sarcoidosis was significantly higher than in healthy subjects (P < 0·05) and IPF patients (P < 0·01). Furthermore, there was a significant correlation between serum concentrations of sl-selectin and the number of l-selectin-negative T lymphocytes in BALF (r = 0·535, P < 0·01). Our results suggest that l-selectin may be involved in T lymphocyte alveolitis in patients with active pulmonary sarcoidosis. PMID:10886252

  12. 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.

  13. Advances in the study of HLA-restricted epitope vaccines

    PubMed Central

    Zhao, Lingxiao; Zhang, Min; Cong, Hua

    2013-01-01

    Vaccination is a proven strategy for protection from disease. An ideal vaccine would include antigens that elicit a safe and effective protective immune response. HLA-restricted epitope vaccines, which include T-lymphocyte epitopes restricted by HLA alleles, represent a new and promising immunization approach. In recent years, research in HLA-restricted epitope vaccines for the treatment of tumors and for the prevention of viral, bacterial, and parasite-induced infectious diseases have achieved substantial progress. Approaches for the improvement of the immunogenicity of epitope vaccines include (1) improving the accuracy of the methods used for the prediction of epitopes, (2) making use of additional HLA-restricted CD8+ T-cell epitopes, (3) the inclusion of specific CD4+ T-cell epitopes, (4) adding B-cell epitopes to the vaccine construction, (5) finding more effective adjuvants and delivery systems, (6) using immunogenic carrier proteins, and (7) using multiple proteins as epitopes sources. In this manuscript, we review recent research into HLA-restricted epitope vaccines. PMID:23955319

  14. An Act of Balance Between Adaptive and Maladaptive Immunity in Depression: a Role for T Lymphocytes.

    PubMed

    Toben, Catherine; Baune, Bernhard T

    2015-12-01

    Historically the monoaminergic neurotransmitter system, in particular the serotonergic system, was seen as being responsible for the pathophysiology of major depressive disorder (MDD). With the advent of psychoneuroimmunology an important role of the immune system in the interface between the central nervous systems (CNS) and peripheral organ systems has emerged. In addition to the well-characterised neurobiological activities of cytokines, T cell function in the context of depression has been neglected so far. In this review we will investigate the biological roles of T cells in depression. Originally it was thought that the adaptive immune arm including T lymphocytes was excluded from the CNS. It is now clear that peripheral naïve T cells not only carry out continuous surveillance within the brain but also maintain neural plasticity. Furthermore animal studies demonstrate that regulatory T lymphocytes can provide protection against maladaptive behavioural responses associated with depression. Psychogenic stress as a major inducer of depression can lead to transient trafficking of T lymphocytes into the brain stimulating the secretion of certain neurotrophic factors and cytokines. The separate and combined mechanism of CD4 and CD8 T cell activation is likely to determine the response pattern of CNS specific neurokines and neurotrophins. Under chronic stress-induced neuroinflammatory conditions associated with depression, T cell responses may become maladaptive and can be involved in neurodegeneration. Additionally, intracellular adhesion and MHC molecule expression as well as glucocorticoid receptor expression within the brain may play a role in determining T lymphocyte functionality in depression. Taken together, T lymphocyte mechanisms, which confer susceptibility or resilience to MDD, are not yet fully understood. Further insight into the cellular and molecular mechanisms which balance the adaptive and maladaptive roles of T lymphocytes may provide a better

  15. The Immunosuppressive Activity of Amniotic Membrane Mesenchymal Stem Cells on T Lymphocytes

    PubMed Central

    Alikarami, Fatemeh; Yari, Fatemeh; Amirizadeh, Naser; Nikougoftar, Mahin; Jalili, Mohammad Ali

    2015-01-01

    Background: Mesenchymal Stem Cells (MSCs) are isolated from different sources like placenta. The placenta and its membranes like Amniotic Membrane (AM) are readily available and easy to work with. There is only limited knowledge on the immunomodulatory properties of human Amniotic Membrane-derived Mesenchymal Stem Cells (hAM-MSCs). The aim of this study was to survey the suppressive activity of hAM-MSCs on T lymphocytes in vitro. Methods: Human AMs were obtained after caesarean section births from healthy women. After enzymatic digestion, cells were cultured and hAM-MSCs were obtained. In addition, human T lymphocytes were isolated and co-cultured with hAM-MSCs for 72 hr in the presence or absence of phytohemagglutinin (PHA). Subsequently, proliferation of T cells was analyzed using BrdU and subsequently flow cytometry technique. Besides, the production of IL-4 and IFN-γ was examined by ELISA method. Additionally, the expression of activation markers (CD38, HLA-DR) was studied on T lymphocytes by flow cytometry technique. Results: It was revealed that hAM-MSCs could significantly suppress the proliferation of T lymphocytes (p≤0.01) and significantly decrease the production of IFN-γ by T cells (p<0.05). hAM-MSCs also down regulated the expression of activation markers on the surface of T lymphocytes, CD38 and HLA-DR. The difference was significant between the case and control samples (p<0.05). All the comparisons were carried out between the case (Tcell+PHA+hAM-MSCs) and control (Tcell+PHA) groups. Conclusion: In conclusion, hAM-MSCs could inhibit the (mitogen-activated) T cells even in the absence of blood monocytes. Besides, hAM-MSCs-mediated inhibition of T lymphocytes was combined with down regulation of activation markers. PMID:26306147

  16. Characterisation of macaque testicular leucocyte populations and T-lymphocyte immunity.

    PubMed

    De Rose, Robert; Fernandez, Caroline S; Hedger, Mark P; Kent, Stephen J; Winnall, Wendy R

    2013-12-01

    The rodent testis is well established as a site of immune privilege where both innate and acquired immune responses are suppressed. Immune cells and responses within human or non-human primate testes, by contrast, are poorly characterised. This study used multi-colour flow cytometry to characterise the leukocytes in testicular cells isolated from 12 young adult pigtail macaques (Macaca nemestrina) by collagenase dispersal, and to measure the cytokine responses of macaque testicular T-lymphocytes to mitogens. B-lymphocytes and granulocytes were present in very low numbers (0.24% and 3.3% of leukocytes respectively), indicating minimal blood contamination. A median of 30.8% of the recovered testicular leukocytes were CD3+ lymphocytes, with CD4 and CD8 T-lymphocyte proportions similar to those in the blood. The proportion of naïve T-lymphocytes in the testis was low, with significantly higher frequencies of central memory cells, compared with the blood. A median of 42.7% of the testicular leukocytes were CD163+ macrophages, while 4.5% were CD14+CD163- monocyte-like macrophages. Small populations of myeloid and plasmacytoid dendritic cells, NK cells and NKT cells were also detected. Following mitogen stimulation, 19.7% of blood T-lymphocytes produced IFNγ and/or TNF, whereas significantly fewer (4.4%) of the testicular T-lymphocytes responded to stimulation. Our results characterise the immune cells within the adult macaque testis and identify a suppression of T-lymphocyte responses. This study provides a baseline to examine the immunology of the primate testis and suggests that testicular immune privilege could also be present in primates. PMID:24139314

  17. Maternal depression is associated with DNA methylation changes in cord blood T lymphocytes and adult hippocampi.

    PubMed

    Nemoda, Z; Massart, R; Suderman, M; Hallett, M; Li, T; Coote, M; Cody, N; Sun, Z S; Soares, C N; Turecki, G; Steiner, M; Szyf, M

    2015-01-01

    Depression affects 10-15% of pregnant women and has been associated with preterm delivery and later developmental, behavioural and learning disabilities. We tested the hypothesis that maternal depression is associated with DNA methylation alterations in maternal T lymphocytes, neonatal cord blood T lymphocytes and adult offspring hippocampi. Genome-wide DNA methylation of CD3+ T lymphocytes isolated from 38 antepartum maternal and 44 neonatal cord blood samples were analyzed using Illumina Methylation 450 K microarrays. Previously obtained methylation data sets using methylated DNA immunoprecipitation and array-hybridization of 62 postmortem hippocampal samples of adult males were re-analyzed to test associations with history of maternal depression. We found 145 (false discovery rate (FDR) q<0.05) and 2520 (FDR q<0.1) differentially methylated CG-sites in cord blood T lymphocytes of neonates from the maternal depression group as compared with the control group. However, no significant DNA methylation differences were detected in the antepartum maternal T lymphocytes of our preliminary data set. We also detected 294 differentially methylated probes (FDR q<0.1) in hippocampal samples associated with history of maternal depression. We observed a significant overlap (P=0.002) of 33 genes with changes in DNA methylation in T lymphocytes of neonates and brains of adult offspring. Many of these genes are involved in immune system functions. Our results show that DNA methylation changes in offspring associated with maternal depression are detectable at birth in the immune system and persist to adulthood in the brain. This is consistent with the hypothesis that system-wide epigenetic changes are involved in life-long responses to maternal depression in the offspring. PMID:25849984

  18. Broadly Neutralizing Antibody VRC01 Prevents HIV-1 Transmission from Plasmacytoid Dendritic Cells to CD4 T Lymphocytes

    PubMed Central

    Lederle, Alexandre; Laumond, Géraldine; Ducloy, Camille; Schmidt, Sylvie; Decoville, Thomas

    2014-01-01

    Plasmacytoid dendritic cells (pDC) poorly replicate human immunodeficiency virus type 1 (HIV-1) but efficiently transfer HIV-1 to adjacent CD4 T lymphocytes. We found that coculture with T lymphocytes downregulates SAMHD1 expression, enhances HIV-1 replication, and increases pDC maturation and alpha interferon (IFN-α) secretion. HIV-1 transfer to T lymphocytes is inhibited by broadly neutralizing antibody VRC01 with efficiency similar to that of cell-free infection of T lymphocytes. Interestingly, prevention of HIV-1 transmission by VRC01 retains IFN-α secretion. These results emphasize the multiple functions of VRC01 in protection against HIV-1 acquisition. PMID:24965460

  19. Testing for HLA/peptide tetramer-binding to the T cell receptor complex on human T lymphocytes.

    PubMed

    Weder, Pauline; Schumacher, Ton N M; Spits, Hergen; Luiten, Rosalie M

    2012-01-01

    HLA/peptide tetramers are frequently used for ex vivo monitoring of disease- or vaccine-induced T cell immune responses and for T cell epitope identification. However, when low-levels HLA/peptide tetramer-positive T cell populations are encountered, it is difficult to ascertain whether this represents a true T cell receptor (TCR)-mediated interaction or background signal. To address this issue, we have developed a method for both HLA class I and class II tetramer assays to confirm tetramer-binding to the TCR/CD3 complex. Preincubation of T cells with anti-CD3 mAb SPV-T3b and subsequent crosslinking interferes with the binding of HLA/peptide tetramers to the TCR/CD3 complex and thereby indicates to what extent HLA/peptide tetramer binds through interaction with TCR/CD3 complex. SPV-T3b pretreatment results in a 2- to 10-fold decrease in tetramer-binding intensity to antigen-specific CD8+ or CD4+ T cells, whereas background reactivity of HLA/peptide tetramers containing HIV-derived peptide in HIV-negative donors remained unchanged. SPV-T3b pretreatment forms a valuable tool to verify tetramer-based detection of antigen-specific T cells during the monitoring of immune responses in clinical studies. PMID:24371571

  20. Effect of tumor growth on migratory properties of T lymphocytes in rats.

    PubMed

    Klobusická, M; Koníková, E; Novotná, L

    1980-01-01

    The dynamics of changes was followed in the migratory properties of T lymphocytes from lymphoid organs of tumor-bearing rats, labeled in vitro with 3H-uridine and injected i.v. to normal recipients, a comparison being made with the migration of T cells from normal donors in syngeneic recipients. The progressive tumor growth was found to correlate with a decline of the ability of spleen T cells from a tumor-bearing rat to migrate to the spleen and lymph nodes of normal animals, following a transient striking migration in the early stages after inoculation with tumor cells. The site of an intensive migration was the liver. T lymphocytes of lymph node draining tumor migrated in correlation with its growth in an enhanced percentage into the spleen, and in a reduced ratio to the lymph node of a normal recipient. T lymphocyte migration of all the lymphoid organs followed became normalized in the stage of the tumor rejection. Peripheral blood T lymphocytes from a tumor-bearing donor showed a depressed ability to migrate into normal lymphoid organs, while the migration rate of thymocytes from such donors in normal recipients underwent no change with the exception of an increased migration into the liver during tumor regression. The results showed changes in the migratory properties of labeled T cells to depend on the immune status of the donor and the lymphoid organ source of the injected lymphocytes. PMID:6973097

  1. Heparanase promotes tumor infiltration and antitumor activity of CAR-redirected T-lymphocytes

    PubMed Central

    Caruana, Ignazio; Savoldo, Barbara; Hoyos, Valentina; Weber, Gerrit; Liu, Hao; Kim, Eugene S.; Ittmann, Michael M.; Marchetti, Dario; Dotti, Gianpietro

    2015-01-01

    Adoptive transfer of chimeric antigen receptor (CAR)-redirected T lymphocytes (CAR-T cells) has had less striking effects in solid tumors1–3 than in lymphoid malignancies4, 5. Although active tumor-mediated immunosuppression may play a role in limiting efficacy6, functional changes in T lymphocytes following their ex vivo manipulation may also account for cultured CAR-T cells’ reduced ability to penetrate stroma-rich solid tumors. We therefore studied the capacity of human in vitro-cultured CAR-T cells to degrade components of the extracellular matrix (ECM). In contrast to freshly isolated T lymphocytes, we found that in vitro-cultured T lymphocytes lack expression of the enzyme heparanase (HPSE) that degrades heparan sulphate proteoglycans, which are main components of ECM. We found that HPSE mRNA is down regulated in in vitro-expanded T cells, which may be a consequence of p53 binding to the HPSE gene promoter. We therefore engineered CAR-T cells to express HPSE and showed improved capacity to degrade ECM, which promoted tumor T-cell infiltration and antitumor activity. Employing this strategy may enhance the activity of CAR-T cells in individuals with stroma-rich solid tumors. PMID:25849134

  2. High-Efficiency Transfection of Primary Human and Mouse T Lymphocytes Using RNA Electroporation

    PubMed Central

    Zhao, Yangbing; Zheng, Zhili; Cohen, Cyrille J.; Gattinoni, Luca; Palmer, Douglas C.; Restifo, Nicholas P.; Rosenberg, Steven A.; Morgan, Richard A.

    2006-01-01

    The use of nonviral gene transfer methods in primary lymphocytes has been hampered by low gene transfer efficiency and high transfection-related toxicity. In this report, high gene transfection efficiency with low transfection-related toxicity was achieved by electroporation using in vitro-transcribed mRNA. Using these methods, >90% transgene expression with >80% viable cells was observed in stimulated primary human and murine T lymphocytes transfected with GFP or mCD62L. Electroporation of unstimulated human PBMCs or murine splenocytes with GFP RNA yielded 95 and 56% GFP+ cells, respectively. Electroporation of mRNA for NY-ESO-1, MART-1, and p53 antigen-specific TCRs into human T lymphocytes redirected these lymphocytes to recognize melanoma cell lines in an MHC-restricted manner. The onset of gene expression was rapid (within 30 min) and durable (up to 7 days postelectroporation) using both GFP and TCR-mediated recognition of target cells. There was no adverse effect observed on the T lymphocytes subjected to RNA electroporation evaluated by cell growth rate, annexin-V staining of apoptotic cells, BrdU incorporation, tumor antigen-specific recognition or antigen-specific TCR affinity. The results of this study indicate that mRNA electroporation provides a powerful tool to introduce genes into both human and murine primary T lymphocytes. PMID:16140584

  3. Activation Effects of Polysaccharides of Flammulina velutipes Mycorrhizae on the T Lymphocyte Immune Function

    PubMed Central

    Yan, Zheng-Fei; Mao, Xin-Xin

    2014-01-01

    Flammulina velutipes mycorrhizae have increasingly been produced with increasing of F. velutipes production. A mouse model was thus used to examine potential effect of F. velutipes mycorrhizae on the immune function. Fifty female Wistar mice (5-weeks-old) weighed 15–20 g were randomly allocated into five groups. Polysaccharide of F. velutipes mycorrhizae were treated with mice and mice spleen lymphocytes. The levels of CD3+, CD4+, and CD8+ T lymphocyte, interleukin-2 (IL-2), and tumor necrosis factor-a (TNF-α) were determined. The results showed that the proportions of CD3+, and CD4+ T lymphocyte, the ratio of CD4+/CD8+, and the levels of IL-2 and TNF-a were significantly increased in polysaccharide of F. velutipes mycorrhizae, while the proportion of CD8+ T lymphocyte was decreased in polysaccharide of F. velutipes mycorrhizae-dose dependent manner. Our findings indicated that a long term exposure of polysaccharide of F. velutipes mycorrhizae could activate the T lymphocyte immune function. Polysaccharide of F. velutipes mycorrhizae was expected to develop into the immune health products. PMID:25133194

  4. The development of in vitro mutagenicity testing systems using T-lymphocytes

    SciTech Connect

    Albertini, R.J.

    1993-05-01

    This annual report describes progress in studies on hprt mutations induced by radon or Indium 111 along with the corresponding mutation frequency, cloning and molecular spectra in human T-lymphocytes. Parallel studies on the mutation susceptibility between individuals is being investigated by hprt mutation studies on ataxia telangiectasia and xeroderma pigmentosum.

  5. HIV infection presenting proliferation of CD8+ T lymphocyte and hemophagocytic lymphohistiocytosis.

    PubMed

    Usman, Mohammad; Thapa, Sudeep D; Hadid, Hiba; Yessayan, Lenar T

    2016-04-01

    Hemophagocytic lymphohistiocytosis is a rare hyperinflammatory disorder characterised by CD8+ T lymphocyte activation and hypercytokinemia. Autoimmune disorders including hemophagocytic lymphohistiocytosis have been described in HIV patients; however, it is a rare initial presentation of HIV infection. We present an unusual case of HIV infection presenting with hemophagocytic lymphohistiocytosis. PMID:25941054

  6. Heparanase promotes tumor infiltration and antitumor activity of CAR-redirected T lymphocytes.

    PubMed

    Caruana, Ignazio; Savoldo, Barbara; Hoyos, Valentina; Weber, Gerrit; Liu, Hao; Kim, Eugene S; Ittmann, Michael M; Marchetti, Dario; Dotti, Gianpietro

    2015-05-01

    Adoptive transfer of chimeric antigen receptor (CAR)-redirected T lymphocytes (CAR-T cells) has had less striking therapeutic effects in solid tumors than in lymphoid malignancies. Although active tumor-mediated immunosuppression may have a role in limiting the efficacy of CAR-T cells, functional changes in T lymphocytes after their ex vivo manipulation may also account for the reduced ability of cultured CAR-T cells to penetrate stroma-rich solid tumors compared with lymphoid tissues. We therefore studied the capacity of human in vitro-cultured CAR-T cells to degrade components of the extracellular matrix (ECM). In contrast to freshly isolated T lymphocytes, we found that in vitro-cultured T lymphocytes lack expression of the enzyme heparanase (HPSE), which degrades heparan sulfate proteoglycans, the main components of ECM. We found that HPSE mRNA is downregulated in in vitro-expanded T cells, which may be a consequence of p53 (officially known as TP53, encoding tumor protein 53) binding to the HPSE gene promoter. We therefore engineered CAR-T cells to express HPSE and showed their improved capacity to degrade the ECM, which promoted tumor T cell infiltration and antitumor activity. The use of this strategy may enhance the activity of CAR-T cells in individuals with stroma-rich solid tumors. PMID:25849134

  7. Myxoma virus suppresses proliferation of activated T lymphocytes yet permits oncolytic virus transfer to cancer cells.

    PubMed

    Villa, Nancy Y; Wasserfall, Clive H; Meacham, Amy M; Wise, Elizabeth; Chan, Winnie; Wingard, John R; McFadden, Grant; Cogle, Christopher R

    2015-06-11

    Allogeneic hematopoietic cell transplant (allo-HCT) can be curative for certain hematologic malignancies, but the risk of graft-versus-host disease (GVHD) is a major limitation for wider application. Ideally, strategies to improve allo-HCT would involve suppression of T lymphocytes that drive GVHD while sparing those that mediate graft-versus-malignancy (GVM). Recently, using a xenograft model, we serendipitously discovered that myxoma virus (MYXV) prevented GVHD while permitting GVM. In this study, we show that MYXV binds to resting, primary human T lymphocytes but will only proceed into active virus infection after the T cells receive activation signals. MYXV-infected T lymphocytes exhibited impaired proliferation after activation with reduced expression of interferon-γ, interleukin-2 (IL-2), and soluble IL-2Rα, but did not affect expression of IL-4 and IL-10. MYXV suppressed T-cell proliferation in 2 patterns (full vs partial) depending on the donor. In terms of GVM, we show that MYXV-infected activated human T lymphocytes effectively deliver live oncolytic virus to human multiple myeloma cells, thus augmenting GVM by transfer of active oncolytic virus to residual cancer cells. Given this dual capacity of reducing GVHD plus increasing the antineoplastic effectiveness of GVM, ex vivo virotherapy with MYXV may be a promising clinical adjunct to allo-HCT regimens. PMID:25904246

  8. Myxoma virus suppresses proliferation of activated T lymphocytes yet permits oncolytic virus transfer to cancer cells

    PubMed Central

    Villa, Nancy Y.; Wasserfall, Clive H.; Meacham, Amy M.; Wise, Elizabeth; Chan, Winnie; Wingard, John R.; McFadden, Grant

    2015-01-01

    Allogeneic hematopoietic cell transplant (allo-HCT) can be curative for certain hematologic malignancies, but the risk of graft-versus-host disease (GVHD) is a major limitation for wider application. Ideally, strategies to improve allo-HCT would involve suppression of T lymphocytes that drive GVHD while sparing those that mediate graft-versus-malignancy (GVM). Recently, using a xenograft model, we serendipitously discovered that myxoma virus (MYXV) prevented GVHD while permitting GVM. In this study, we show that MYXV binds to resting, primary human T lymphocytes but will only proceed into active virus infection after the T cells receive activation signals. MYXV-infected T lymphocytes exhibited impaired proliferation after activation with reduced expression of interferon-γ, interleukin-2 (IL-2), and soluble IL-2Rα, but did not affect expression of IL-4 and IL-10. MYXV suppressed T-cell proliferation in 2 patterns (full vs partial) depending on the donor. In terms of GVM, we show that MYXV-infected activated human T lymphocytes effectively deliver live oncolytic virus to human multiple myeloma cells, thus augmenting GVM by transfer of active oncolytic virus to residual cancer cells. Given this dual capacity of reducing GVHD plus increasing the antineoplastic effectiveness of GVM, ex vivo virotherapy with MYXV may be a promising clinical adjunct to allo-HCT regimens. PMID:25904246

  9. T lymphocytes control microbial composition by regulating the abundance of Vibrio in the zebrafish gut

    PubMed Central

    Brugman, Sylvia; Schneeberger, Kerstin; Witte, Merlijn; Klein, Mark R; van den Bogert, Bartholomeus; Boekhorst, Jos; Timmerman, Harro M; Boes, Marianne L; Kleerebezem, Michiel; Nieuwenhuis, Edward ES

    2014-01-01

    Dysbiosis of the intestinal microbial community is considered a risk factor for development of chronic intestinal inflammation as well as other diseases such as diabetes, obesity and even cancer. Study of the innate and adaptive immune pathways controlling bacterial colonization has however proven difficult in rodents, considering the extensive cross-talk between bacteria and innate and adaptive immunity. Here, we used the zebrafish to study innate and adaptive immune processes controlling the microbial community. Zebrafish lack a functional adaptive immune system in the first weeks of life, enabling study of the innate immune system in the absence of adaptive immunity. We show that in wild type zebrafish, the initial lack of adaptive immunity associates with overgrowth of Vibrio species (a group encompassing fish and human pathogens), which is overcome upon adaptive immune development. In Rag1-deficient zebrafish (lacking adaptive immunity) Vibrio abundance remains high, suggesting that adaptive immune processes indeed control Vibrio species. Using cell transfer experiments, we confirm that adoptive transfer of T lymphocytes, but not B lymphocytes into Rag1-deficient recipients suppresses outgrowth of Vibrio. In addition, ex vivo exposure of intestinal T lymphocytes to Rag1-deficient microbiota results in increased interferon-gamma expression by these T lymphocytes, compared to exposure to wild type microbiota. In conclusion, we show that T lymphocytes control microbial composition by effectively suppressing the outgrowth of Vibrio species in the zebrafish intestine. PMID:25536157

  10. T lymphocytes control microbial composition by regulating the abundance of Vibrio in the zebrafish gut.

    PubMed

    Brugman, Sylvia; Schneeberger, Kerstin; Witte, Merlijn; Klein, Mark R; van den Bogert, Bartholomeus; Boekhorst, Jos; Timmerman, Harro M; Boes, Marianne L; Kleerebezem, Michiel; Nieuwenhuis, Edward E S

    2014-01-01

    Dysbiosis of the intestinal microbial community is considered a risk factor for development of chronic intestinal inflammation as well as other diseases such as diabetes, obesity and even cancer. Study of the innate and adaptive immune pathways controlling bacterial colonization has however proven difficult in rodents, considering the extensive cross-talk between bacteria and innate and adaptive immunity. Here, we used the zebrafish to study innate and adaptive immune processes controlling the microbial community. Zebrafish lack a functional adaptive immune system in the first weeks of life, enabling study of the innate immune system in the absence of adaptive immunity. We show that in wild type zebrafish, the initial lack of adaptive immunity associates with overgrowth of Vibrio species (a group encompassing fish and human pathogens), which is overcome upon adaptive immune development. In Rag1-deficient zebrafish (lacking adaptive immunity) Vibrio abundance remains high, suggesting that adaptive immune processes indeed control Vibrio species. Using cell transfer experiments, we confirm that adoptive transfer of T lymphocytes, but not B lymphocytes into Rag1-deficient recipients suppresses outgrowth of Vibrio. In addition, ex vivo exposure of intestinal T lymphocytes to Rag1-deficient microbiota results in increased interferon-gamma expression by these T lymphocytes, compared to exposure to wild type microbiota. In conclusion, we show that T lymphocytes control microbial composition by effectively suppressing the outgrowth of Vibrio species in the zebrafish intestine. PMID:25536157

  11. T Lymphocyte Maturation Is Impaired in Healthy Young Individuals Carrying Trisomy 21 (Down Syndrome)

    ERIC Educational Resources Information Center

    Guazzarotti, Laura; Trabattoni, Daria; Castelletti, Eleonora; Boldrighini, Benedetta; Piacentini, Luca; Duca, Piergiorgio; Beretta, Silvia; Pacei, Michela; Caprio, Cristiana; Vigano, Alessandra; di Natale, Berardo; Zuccotti, Gian Vincenzo; Clerici, Mario

    2009-01-01

    Cytokine production, immune activation, T lymphocytes maturation, and serum IL-7 concentration were examined in 24 youngsters with Down syndrome and no acquired diseases (healthy Down syndrome [12 prepubertal, 13 pubertal]) and 42 age- and gender-matched controls (20 prepubertal, 22 pubertal). Results showed that a complex immune and impairment is…

  12. Microfluidics for T- Lymphocyte Cell Separation and Inflammation Monitoring in Burn Patients

    PubMed Central

    Rosenbach, Alan E.; Koria, Piyush; Goverman, Jeremy; Kotz, Kenneth T.; Gupta, Amit; Yu, Ming; Fagan, Shawn P.; Irimia, Daniel; Tompkins, Ronald G.

    2011-01-01

    Severe burns result in T-lymphocyte specific immunologic changes. In addition to decreased levels of circulating lymphocytes, changes in cytokine secretion and receptor expression also take place. Our finer understanding of the inflammatory response has led to the development of immune-targeted therapeutics, requiring specialized gene-expression monitoring. The emerging field of bio-micro-electromechanical systems can be used to isolate highly pure T-lymphocytes in a clinically relevant and timely manner for downstream genomic analysis. Blood samples from healthy volunteers and burn-injured patients were introduced into microfluidic devices developed in our laboratory. Utilizing cell-affinity-chromatography for positive selection of T-lymphocytes, the devices served as a platform for RNA extraction and downstream cytokine analysis via quantitative real time PCR. From a 0.5-mL whole blood sample, the microfluidic devices captured highly pure T-lymphocytes from healthy volunteers and burn-injured patients. Cell capture was of sufficient quantity, and extracted RNA was of sufficient quality, for evaluating the gene expression of cytokines: interferon-gamma, interleukin-2, interleukin-4, and interleukin-10. Microfluidics is a useful tool in processing blood from burn-injured patients. Though in its very early stages of development, cell-specific information obtained by this platform/technology will likely be an important component of near-patient molecular diagnostics and personalized medicine. PMID:21348958

  13. Vpr Promotes Macrophage-Dependent HIV-1 Infection of CD4+ T Lymphocytes.

    PubMed

    Collins, David R; Lubow, Jay; Lukic, Zana; Mashiba, Michael; Collins, Kathleen L

    2015-07-01

    Vpr is a conserved primate lentiviral protein that promotes infection of T lymphocytes in vivo by an unknown mechanism. Here we demonstrate that Vpr and its cellular co-factor, DCAF1, are necessary for efficient cell-to-cell spread of HIV-1 from macrophages to CD4+ T lymphocytes when there is inadequate cell-free virus to support direct T lymphocyte infection. Remarkably, Vpr functioned to counteract a macrophage-specific intrinsic antiviral pathway that targeted Env-containing virions to LAMP1+ lysosomal compartments. This restriction of Env also impaired virological synapses formed through interactions between HIV-1 Env on infected macrophages and CD4 on T lymphocytes. Treatment of infected macrophages with exogenous interferon-alpha induced virion degradation and blocked synapse formation, overcoming the effects of Vpr. These results provide a mechanism that helps explain the in vivo requirement for Vpr and suggests that a macrophage-dependent stage of HIV-1 infection drives the evolutionary conservation of Vpr. PMID:26186441

  14. Vpr Promotes Macrophage-Dependent HIV-1 Infection of CD4+ T Lymphocytes

    PubMed Central

    Collins, David R.; Lubow, Jay; Lukic, Zana; Mashiba, Michael; Collins, Kathleen L.

    2015-01-01

    Vpr is a conserved primate lentiviral protein that promotes infection of T lymphocytes in vivo by an unknown mechanism. Here we demonstrate that Vpr and its cellular co-factor, DCAF1, are necessary for efficient cell-to-cell spread of HIV-1 from macrophages to CD4+ T lymphocytes when there is inadequate cell-free virus to support direct T lymphocyte infection. Remarkably, Vpr functioned to counteract a macrophage-specific intrinsic antiviral pathway that targeted Env-containing virions to LAMP1+ lysosomal compartments. This restriction of Env also impaired virological synapses formed through interactions between HIV-1 Env on infected macrophages and CD4 on T lymphocytes. Treatment of infected macrophages with exogenous interferon-alpha induced virion degradation and blocked synapse formation, overcoming the effects of Vpr. These results provide a mechanism that helps explain the in vivo requirement for Vpr and suggests that a macrophage-dependent stage of HIV-1 infection drives the evolutionary conservation of Vpr. PMID:26186441

  15. Differential Inhibition of T Lymphocyte Proliferation and Cytokine Synthesis by [6]-Gingerol, [8]-Gingerol, and [10]-Gingerol.

    PubMed

    Bernard, Megan; Furlong, Suzanne J; Power Coombs, Melanie R; Hoskin, David W

    2015-11-01

    [6]-Gingerol, [8]-gingerol, and [10]-gingerol are pungent components of fresh ginger, extracts of which inhibit various components of the inflammatory response. Because little is known regarding the effect of gingerols with different unbranched alkyl side chain lengths on the activation and effector function of T lymphocytes, we compared the effects of [6]-gingerol, [8]-gingerol, and [10]-gingerol on murine T lymphocyte proliferation, expression of CD25 and CD69 activation markers, cytokine synthesis, and interleukin (IL)-2 receptor signaling. All three gingerols inhibited DNA synthesis by T lymphocytes, as well as interferon-γ synthesis. In contrast, only [8]-gingerol and [10]-gingerol inhibited CD25 and CD69 expression, and IL-2 synthesis. None of the gingerols affected IL-4 synthesis. Exogenous IL-2 enhanced T lymphocyte proliferation in the presence of [6]-gingerol but did not significantly increase T lymphocyte proliferation in the presence of [8]-gingerol or [10]-gingerol. In line with this finding, [8]-gingerol and [10]-gingerol impaired IL-2-induced proliferation of CTLL-2 cells, but constitutive CD25 expression was unaffected, indicating inhibition of IL-2 receptor signaling. In general, [10]-gingerol and [8]-gingerol were more potent inhibitors of T lymphocytes than [6]-gingerol. Suppression of T lymphocyte responses by gingerols suggests that these phytochemicals may be beneficial in chronic inflammatory conditions associated with excessive or inappropriate T lymphocyte activation. PMID:26178781

  16. Killing of Brucella antigen-sensitized macrophages by T lymphocytes in bovine brucellosis.

    PubMed

    Wyckoff, John H; Potts, Richard D

    2007-12-15

    The present study was an investigation into the role of T lymphocytes in the killing of antigen-sensitized macrophages (M Phi) in bovine brucellosis. Following confirmation of bovine T lymphocyte cell lines derived from Brucella abortus Strain 19 vaccinated steers as antigen-specific in proliferation studies using various antigens, we adapted an apoptosis assay for evaluation of cytotoxicity by these bovine T cells against autologous monocyte-derived macrophages (MDM Phi) as target cells. Various B. abortus antigen preparations were tested including whole gamma-irradiated B. abortus bacteria (gamma BA), a soluble cytosolic protein fraction and a membrane-associated protein fraction. Both polyclonal and cloned T lymphocyte cell lines exhibited cytotoxicity against MDM Phi targets in an antigen-specific fashion. Polyclonal and cloned T lymphocyte cell lines demonstrated cytotoxic responses to varying degrees against B. abortus antigens regardless of whether the antigen used was whole nonviable bacteria, a soluble protein extract or a membrane-associated fraction of extracted bacteria. To further develop correlation of these responses to an in vivo host defense mechanism, cytotoxicity was evaluated using target cells that had been infected with live B. abortus S19 or B. abortus Strain 2308. Cytotoxic responses were also demonstrated consistently against infected targets with either strain of B. abortus although in most cases, cytotoxicity was higher against target cells sensitized with gamma BA compared to those infected with live bacteria. Cloned T lymphocyte cell lines were all CD4+, CD8(-) cells indicating that the observed cytotoxic responses were most likely due to an inflammatory Th1 response and may represent an important host defense mechanism induced by vaccination with live attenuated strains of B. abortus in cattle. PMID:17904229

  17. T Lymphocyte Density and Distribution in Human Colorectal Mucosa, and Inefficiency of Current Cell Isolation Protocols

    PubMed Central

    Preza, Gloria Cuevas; Yang, Otto O.; Elliott, Julie; Anton, Peter A.; Ochoa, Maria T.

    2015-01-01

    Mucosal tissues are critical immune effector sites containing complex populations of leukocytes in a tissue microenvironment that remains incompletely understood. We identify and quantify in human distal colorectal tissue absolute mucosal CD3+ lymphocytes, including CD4+ and CD8+ subsets, by direct visualization using immunohistochemistry (IHC), immunofluorescence (IF), and an automated counting protocol (r2=0.90). Sigmoid and rectal mucosal tissues are both densely packed with T lymphocytes in the mucosal compartment. Both compartments had similar densities of CD3+ T lymphocytes with 37,400 ± 2,801 cells/mm3 and 33,700 ± 4,324 cell/mm3, respectively. Sigmoid mucosa contained 57% CD3+CD4+ and 40% CD3+CD8+ T lymphocytes which calculates to 21,300 ± 1,476/mm3 and 15,000 ± 275/mm3 T lymphocytes, respectively. Rectal mucosa had 57% CD3+CD4+ and 42% CD3+CD8+ or 21,577 ± 332, and 17,090 ± 1,206 cells/mm3, respectively. By comparison, sigmoid mucosal biopsies subjected to conventional collagenase digestion, mononuclear cell (MMC) isolation and staining for flow cytometry yielded 4,549 ± 381/mm3 and 2,708 ± 245/mm3 CD4+ and CD8+ T lymphocytes. These data suggest only ~20.7% recovery compared to IHC results for these markers. Further studies will determine if this reflects a selective bias in only CD3+, CD4+ and CD8+ T cells or can be generalized to all flow-analyzed cells from mucosal tissues for phenotyping and functional testing. PMID:25856343

  18. Different stimulating capacity of B and T lymphocytes in primary and secondary allogeneic reactions: cellular detection of HLA-D products on T lymphocytes.

    PubMed

    Wollman, E E; Cohen, D; Fradelizi, D; Sasportes, M; Dausset, J

    1980-11-01

    The present study was undertaken to define the best way to produce and to test primed lymphocyte typing (PLT) cells using B- and T-enriched lymphocyte suspensions. Intrafamilial PLT cells were produced with primed unseparated and T purified lymphocytes against haplo-identical donors' T and B cells. These PLT cells were then restimulated with a panel of related or unrelated individuals' T and B cells and with allogeneic in vitro activated T cells. The best discrimination was obtained when PLT reagents, regardless of the production method, were restimulated by a B-enriched population of peripheral lymphocytes. Furthermore, the results have shown that enriched primed or unprimed T cell suspensions stimulated by enriched T lymphocytes did not give any proliferation. Experiments performed to explain the results led us to distinguish 2 different phenomena: in primary cultures, the addition of monocytes autologous to the responder cell restored the proliferation of enriched T cells stimulated by T lymphocytes. In secondary cultures, the addition of monocytes autologous to the PLT cell did not restore the proliferation of PLT lymphocytes stimulated by enriched T cells. This was shown to be due to the lack of Dr antigen on the stimulating cell: if allogeneically activated T cells were used as stimulating lymphocytes, a DR-specific proliferative response appeared. This correlates with serologic findings were DR determinants are found on activated T cells and not on unprimed T lymphocytes. However, this difference might be only quantitative, since peripheral lymphocytes could be primed by T cells and be DR specifically restimulated. PMID:6968771

  19. Effects of smoking, aromatic amines, and chromates on CD4{sup +} and CD8{sup +} T lymphocytes in male workers

    SciTech Connect

    Tanigawa, Takeshi; Araki, Shunichi; Sata, Fumihiro; Nakata, Akinori; Araki, Takaharu

    1998-07-01

    To investigate effects of smoking, aromatic amines (AAs), and chromates (CRs) on Tlymphocyte subpopulations, the authors measured CD3{sup +}, CD4{sup +}, and CD8{sup +} T lymphocytes in the peripheral blood of 33 nonexposed workers, 25 AA-use workers, 27 AA-production workers, and 19 CR workers (all subjects were males). The number of CD4{sup +} T lymphocytes in smokers of nonexposed workers was significantly larger than that of the nonsmokers; also, the numbers of CD4{sup +} and CD3{sup +} T lymphocytes in smokers of each group of AA-production and AA-use workers were significantly larger than those in nonsmokers. Numbers of CD4{sup +} and CD3{sup +} T lymphocytes in nonsmokers of AA-production and CR workers were significantly smaller than those in nonsmokers of nonexposed workers; the number of CD8{sup +} T lymphocytes in nonsmokers of CR workers was significantly smaller than that in nonsmokers of nonexposed workers.

  20. Phenotypical and functional evaluation of CD8+/S6F1+ T lymphocytes in haemophiliac individuals with HIV-1 infection.

    PubMed Central

    Cavallin, F; Traldi, A; Zambello, R

    1993-01-01

    In this study we investigated the distribution of the S6F1 antigen, an epitope of the lymphocyte function-associated antigen, on CD8+ T lymphocytes in a series of 15 HIV-1+ and 20 HIV-1- haemophiliac patients. MoAbs recognizing the S6F1 antigen have been claimed to distinguish between killer effectors (brightly S6F1+ stained) and suppressor cells (dimly S6F1+ stained) within the CD8+ lymphoid population. In addition, we tried to find a correlation between the spontaneous in vitro immunoglobulin synthesis from patients' peripheral blood lymphocytes and the pattern of S6F1 expression. Although the total number of double-positive CD8+/S6F1+ cells was similar in both HIV-1+ and HIV-1- haemophiliac patients, a significant increase in the CD8+/S6F1+ population bright versus dim was documented in HIV-1-infected with respect to HIV-1- haemophiliacs (bright/dim ratio 3.97 +/- 0.61 versus 0.75 +/- 0.1, respectively, P < 0.005). This finding was correlated to a significant increase in spontaneous in vitro immunoglobulin production in HIV-1+ subjects compared with control haemophiliacs (P < 0.005). Purified CD8+ lymphocytes from HIV-1+ subjects showed a reduced suppressor activity on mitogen-induced immunoglobulin production. Taken together, these data suggest that HIV-1 infection favours the generation of CD8+/S6F1+ bright cells with putative cytotoxic-associated function, leading to a progressive reduction in the number of CD8+/S6F1+ dim suppressor lymphocytes. This phenomenon may contribute to the polyclonal hypergammaglobulinaemia present in HIV-1+ haemophiliac patients. PMID:8324903

  1. 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

  2. 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

  3. Kinetics of Antiviral Activity by Human Immunodeficiency Virus Type 1-Specific Cytotoxic T Lymphocytes (CTL) and Rapid Selection of CTL Escape Virus In Vitro

    PubMed Central

    Van Baalen, C. A.; Schutten, M.; Huisman, R. C.; Boers, P. H. M.; Gruters, R. A.; Osterhaus, A. D. M. E.

    1998-01-01

    The antiviral activity of a CD8+ cytotoxic T-lymphocyte (CTL) clone (TCC108) directed against a newly identified HLA-B14-restricted epitope, human immunodeficiency virus type 1 (HIV-1) Rev(67-75) SAEPVPLQL, was analyzed with respect to its kinetics of target cell lysis and inhibition of HIV-1 production. Addition of TCC108 cells or CD8+ reverse transcriptase-specific CTLs to HLA-matched CD4+ T cells at different times after infection with HIV-1 IIIB showed that infected cells became susceptible to CTL-mediated lysis before peak virus production but after the onset of progeny virus release. When either of these CTLs were added to part of the infected cells immediately after infection, p55 expression and virus production were significantly suppressed. These data support a model in which CTLs, apart from exerting cytolytic activity which may prevent continued virus release, can interfere with viral protein expression during the eclipse phase via noncytolytic mechanisms. TCC108-mediated inhibition of virus replication in peripheral blood mononuclear cells caused rapid selection of a virus with a mutation (69E→K) in the Rev(67-75) CTL epitope which abolished recognition by TCC108 cells. Taken together, these data suggest that both cytolytic and noncytolytic antiviral mechanisms of CTLs can be specifically targeted to HIV-1-infected cells. PMID:9658134

  4. Thermoreversible Poly(ethylene glycol)-g-Chitosan Hydrogel as a Therapeutic T Lymphocyte Depot for Localized Glioblastoma Immunotherapy

    PubMed Central

    2015-01-01

    The outcome for glioblastoma patients remains dismal for its invariably recrudesces within 2 cm of the resection cavity. Local immunotherapy has the potential to eradicate the residual infiltrative component of these tumors. Here, we report the development of a biodegradable hydrogel containing therapeutic T lymphocytes for localized delivery to glioblastoma cells for brain tumor immunotherapy. Thermoreversible poly(ethylene glycol)-g-chitosan hydrogels (PCgels) were optimized for steady T lymphocyte release. Nuclear magnetic resonance spectroscopy confirmed the chemical structure of poly(ethylene glycol)-g-chitosan, and rheological studies revealed that the sol-to-gel transition of the PCgel occurred around ≥32 °C. T lymphocyte invasion through the PCgel and subsequent cytotoxicity to glioblastoma were assessed in vitro. The PCgel was shown to be cellular compatible with T lymphocytes, and the T lymphocytes retain their anti-glioblastoma activity after being encapsulated in the PCgel. T lymphocytes in the PCgel were shown to be more effective in killing glioblastoma than those in the Matrigel control. This may be attributed to the optimal pore size of the PCgel allowing better invasion of T lymphocytes. Our study suggests that this unique PCgel depot may offer a viable approach for localized immunotherapy for glioblastoma. PMID:24890220

  5. Thermoreversible poly(ethylene glycol)-g-chitosan hydrogel as a therapeutic T lymphocyte depot for localized glioblastoma immunotherapy.

    PubMed

    Tsao, Ching-Ting; Kievit, Forrest M; Ravanpay, Ali; Erickson, Ariane E; Jensen, Michael C; Ellenbogen, Richard G; Zhang, Miqin

    2014-07-14

    The outcome for glioblastoma patients remains dismal for its invariably recrudesces within 2 cm of the resection cavity. Local immunotherapy has the potential to eradicate the residual infiltrative component of these tumors. Here, we report the development of a biodegradable hydrogel containing therapeutic T lymphocytes for localized delivery to glioblastoma cells for brain tumor immunotherapy. Thermoreversible poly(ethylene glycol)-g-chitosan hydrogels (PCgels) were optimized for steady T lymphocyte release. Nuclear magnetic resonance spectroscopy confirmed the chemical structure of poly(ethylene glycol)-g-chitosan, and rheological studies revealed that the sol-to-gel transition of the PCgel occurred around ≥32 °C. T lymphocyte invasion through the PCgel and subsequent cytotoxicity to glioblastoma were assessed in vitro. The PCgel was shown to be cellular compatible with T lymphocytes, and the T lymphocytes retain their anti-glioblastoma activity after being encapsulated in the PCgel. T lymphocytes in the PCgel were shown to be more effective in killing glioblastoma than those in the Matrigel control. This may be attributed to the optimal pore size of the PCgel allowing better invasion of T lymphocytes. Our study suggests that this unique PCgel depot may offer a viable approach for localized immunotherapy for glioblastoma. PMID:24890220

  6. In vivo high spatiotemporal resolution visualization of circulating T lymphocytes in high endothelial venules of lymph nodes

    NASA Astrophysics Data System (ADS)

    Choe, Kibaek; Hwang, Yoonha; Seo, Howon; Kim, Pilhan

    2013-03-01

    Lymph nodes (LN) are major checkpoints for circulating T lymphocytes to recognize foreign antigens collected from peripheral tissue. High endothelial venule (HEV) in LN facilitates the effective transmigration of circulating T lymphocytes from the blood into LN. There have been many efforts to visualize T lymphocytes trafficking across HEV to understand the underlying mechanism. However, due to insufficient spatiotemporal resolution and the lack of an in vivo labeling method, clear visualization of dynamic behaviors of rapidly flowing T lymphocytes in HEV and their transmigration have been difficult. In this work, we adapted a custom-designed video-rate laser scanning confocal microscopy system to track individual flowing T lymphocytes in the HEV in real time in vivo. We demonstrate that the HEVs in LN can be clearly identified in vivo with its distinctive cuboidal morphology of endothelial cells fluorescently labeled by intravenously injected anti-CD31 antibody conjugated with Alexa fluorophore. By visualizing the adaptively transferred T lymphocytes, we successfully analyzed dynamic flowing behaviors of T lymphocytes and their transendothelial migration while interacting with the endothelial cells in HEV.

  7. A novel multi-epitope peptide vaccine against cancer: an in silico approach.

    PubMed

    Nezafat, Navid; Ghasemi, Younes; Javadi, Gholamreza; Khoshnoud, Mohammad Javad; Omidinia, Eskandar

    2014-05-21

    Cancer immunotherapy has an outstanding position in cancer prevention and treatment. In this kind of therapy, the immune system is activated to eliminate cancerous cells. Multi-epitope peptide cancer vaccines are manifesting as the next generation of cancer immunotherapy. In the present study, we have implemented various strategies to design an efficient multi-epitope vaccine. CD8+ cytolytic T lymphocytes (CTLs) epitopes, which have a pivotal role in cellular immune responses, helper epitopes and adjuvant, are three crucial components of peptide vaccine. CTL epitopes were determined from two high immunogenic protein Wilms tumor-1 (WT1) and human papillomavirus (HPV) E7 by various servers, which apply different algorithms. CTL epitopes were linked together by AAY and HEYGAEALERAG motifs to enhance epitope presentation. Pan HLA DR-binding epitope (PADRE) peptide sequence and helper epitopes, which have defined from Tetanus toxin fragment C (TTFrC) by various servers, were used to induce CD4+ helper T lymphocytes (HTLs) responses. Additionally, helper epitopes were conjugated together via GPGPG motifs that stimulate HTL immunity. Heparin-Binding Hemagglutinin (HBHA), a novel TLR4 agonist was employed as an adjuvant to polarize CD4+ T cells toward T-helper 1 to induce strong CTL responses. Moreover, the EAAAK linker was introduced to N and C terminals of HBHA for efficient separation. 3D model of protein was generated and predicted B cell epitopes were determined from the surface of built structure. Our protein contains several linear and conformational B cell epitopes, which suggests the antibody triggering property of this novel vaccine. Hence, our final protein can be used for prophylactic or therapeutic usages, because it can potentially stimulate both cellular and humoral immune responses. PMID:24512916

  8. Single injection of CD8+ T lymphocytes derived from hematopoietic stem cells - Mathematical and numerical insights.

    PubMed

    Korpusik, Adam; Kolev, Mikhail

    2016-06-01

    Recently, hematopoietic stem cell (HSC) based therapy is being discussed as a possible treatment for HIV infection. The main advantage of this approach is that it limits the immune impairing effect of infection by introducing an independent influx of antigen-specific cytotoxic T lymphocytes (CTL). In this paper, we present a mathematical approach to predict the dynamics of HSC based therapy. We use a modification of a basic mathematical model for virus induced impairment of help to study how virus - immune system dynamics can be influenced by a single injection of CD8+ T lymphocytes derived from hematopoietic stem cells. Our mathematical and numerical results indicate that a single, large enough dose of genetically derived CTL may lead to restoration of the cellular immune response and result in long-term control of infection. PMID:27095371

  9. Neospora caninum-infected cattle develop parasite-specific CD4+ cytotoxic T lymphocytes.

    PubMed

    Staska, Lauren M; McGuire, Travis C; Davies, Christopher J; Lewin, Harris A; Baszler, Timothy V

    2003-06-01

    Cattle infected with Neospora caninum readily experience transplacental parasite transmission, presumably after maternal parasitemia, leading to abortion or birth of congenitally infected calves. Cytotoxic T lymphocytes (CTL) are important mediators of protective immunity against Toxoplasma gondii, an intracellular apicomplexan protozoan closely related to N. caninum. In this study, N. caninum-specific CTL expanded from peripheral blood mononuclear cells of two major histocompatibility complex-mismatched, experimentally infected cattle were identified by using a (51)Cr release cytotoxicity assay. Enrichment and blocking of CD4(+)- and CD8(+)-T-lymphocyte effector subsets indicated that CD4(+) CTL killed N. caninum-infected, autologous target cells and that killing was mediated through a perforin/granzyme pathway. Detection and characterization of CTL responses to N. caninum in the natural, outbred, bovine host will facilitate identification of immunogens and design of immunization strategies to induce parasite-specific CTL against transplacental N. caninum transmission in cattle. PMID:12761108

  10. Adoptive transfer of resistance to acute Trypanosoma cruzi infection with T-lymphocyte-enriched spleen cells.

    PubMed Central

    Reed, S G

    1980-01-01

    Inbred C57BL/10 mice immunized with live culture forms of Trypanosoma cruzi were resistant to acute infection after challenge with bloodstream forms. Splenic leukocytes or serum from immunized mice were transferred to syngeneic recipients 2 days before of 2 days after challenge. Protection was not observed in recipients of serum, although the serum contained high levels of agglutinating antibody. Unfractionated splenic leukocytes from immunized donors conferred partial protection, and preparations enriched for T lymphocytes were significantly more effective than preparations enriched for B lymphocytes. Recipients of T-lymphocyte-enriched spleen cells had significantly higher survival times and significantly lower parasitemias than did recipients of B-lymphocyte-enriched spleen cells. PMID:6772557

  11. Neospora caninum-Infected Cattle Develop Parasite-Specific CD4+ Cytotoxic T Lymphocytes

    PubMed Central

    Staska, Lauren M.; McGuire, Travis C.; Davies, Christopher J.; Lewin, Harris A.; Baszler, Timothy V.

    2003-01-01

    Cattle infected with Neospora caninum readily experience transplacental parasite transmission, presumably after maternal parasitemia, leading to abortion or birth of congenitally infected calves. Cytotoxic T lymphocytes (CTL) are important mediators of protective immunity against Toxoplasma gondii, an intracellular apicomplexan protozoan closely related to N. caninum. In this study, N. caninum-specific CTL expanded from peripheral blood mononuclear cells of two major histocompatibility complex-mismatched, experimentally infected cattle were identified by using a 51Cr release cytotoxicity assay. Enrichment and blocking of CD4+- and CD8+-T-lymphocyte effector subsets indicated that CD4+ CTL killed N. caninum-infected, autologous target cells and that killing was mediated through a perforin/granzyme pathway. Detection and characterization of CTL responses to N. caninum in the natural, outbred, bovine host will facilitate identification of immunogens and design of immunization strategies to induce parasite-specific CTL against transplacental N. caninum transmission in cattle. PMID:12761108

  12. Curcuma longa attenuates carbon tetrachloride-induced oxidative stress in T-lymphocyte subpopulations.

    PubMed

    Abu-Rizq, H A; Mansour, Mohamed H; Afzal, Mohammad

    2015-01-01

    A comparison of crude curcuminoid extract and purified curcumin was made to evaluate the immunoprotective effect of Curcuma longa (turmeric) Zingiberaceae. Carbon tetrachloride (CCl4) induced selective cytolytic effects among immature (PNA(+)) thymocytes and peripheral helper (CD4(+)) T lymphocytes in the spleen were paralleled by a significant reduction in CD25, CD71, and Con A receptor expression. Treatment with curcumanoid crude extract, at two different doses, showed a significant restoration of lymphocyte viability and CD25, CD71, and Con A receptor expression in both immature (PNA+) thymocytes and splenic helper (CD4(+)) T lymphocytes. Turmeric crude extract, at both low and high dose, was found to be more efficient as compared to purified curcumin, suggesting synergistic effect of curcumin with other components of the crude extract. PMID:25323506

  13. Tumor-Infiltrating γδ T Lymphocytes: Pathogenic Role, Clinical Significance, and Differential Programing in the Tumor Microenvironment

    PubMed Central

    Lo Presti, Elena; Dieli, Franceso; Meraviglia, Serena

    2014-01-01

    There is increasing clinical evidence indicating that the immune system may either promote or inhibit tumor progression. Several studies have demonstrated that tumors undergoing remission are largely infiltrated by T lymphocytes [tumor-infiltrating lymphocytes (TILs)], but on the other hand, several studies have shown that tumors may be infiltrated by TILs endowed with suppressive features, suggesting that TILs are rather associated with tumor progression and unfavorable prognosis. γδ T lymphocytes are an important component of TILs that may contribute to tumor immunosurveillance, as also suggested by promising reports from several small phase-I clinical trials. Typically, γδ T lymphocytes perform effector functions involved in anti-tumor immune responses (cytotoxicity, production of IFN-γ and TNF-α, and dendritic cell maturation), but under appropriate conditions they may divert from the typical Th1-like phenotype and polarize to Th2, Th17, and Treg cells thus acquiring the capability to inhibit anti-tumor immune responses and promote tumor growth. Recent studies have shown a high frequency of γδ T lymphocytes infiltrating different types of cancer, but the nature of this association and the exact mechanisms underlying it remain uncertain and whether or not the presence of tumor-infiltrating γδ T lymphocytes is a definite prognostic factor remains controversial. In this paper, we will review studies of tumor-infiltrating γδ T lymphocytes from patients with different types of cancer, and we will discuss their clinical relevance. Moreover, we will also discuss on the complex interplay between cancer, tumor stroma, and γδ T lymphocytes as a major determinant of the final outcome of the γδ T lymphocyte response. Finally, we propose that targeting γδ T lymphocyte polarization and skewing their phenotype to adapt to the microenvironment might hold great promise for the treatment of cancer. PMID:25505472

  14. Treatment with Interleukin-7 Restores Host Defense against Pneumocystis in CD4+ T-Lymphocyte-Depleted Mice

    PubMed Central

    Samuelson, D. R.; Assouline, B.; Morre, M.; Shellito, J. E.

    2015-01-01

    Pneumocystis pneumonia (PCP) is a major cause of morbidity and mortality in patients with HIV infection. CD4+ T lymphocytes are critical for host defense against this infection, but in the absence of CD4+ T lymphocytes, CD8+ T lymphocytes may provide limited host defense. The cytokine interleukin-7 (IL-7) functions to enhance lymphocyte proliferation, survival, and recruitment of immune cells to sites of infection. However, there is little known about the role of IL-7 in PCP or its potential use as an immunotherapeutic agent. We hypothesized that treatment with recombinant human IL-7 (rhIL-7) would augment host defense against Pneumocystis and accelerate pathogen clearance in CD4-depleted mice. Control and CD4-depleted mice were infected with Pneumocystis, and rhIL-7 was administered via intraperitoneal injection. Our studies indicate that endogenous murine IL-7 is part of the normal host response to Pneumocystis murina and that administration of rhIL-7 markedly enhanced clearance of Pneumocystis in CD4-depleted mice. Additionally, we observed increased recruitment of CD8+ T lymphocytes to the lungs and decreased apoptosis of pulmonary CD8+ T lymphocytes in rhIL-7-treated animals compared to those in untreated mice. The antiapoptotic effect of rhIL-7 was associated with increased levels of Bcl-2 protein in T lymphocytes. rhIL-7 immunotherapy in CD4-depleted mice also increased the number of gamma interferon (IFN-γ)-positive CD8+ central memory T lymphocytes in the lungs. We conclude that rhIL-7 has a potent therapeutic effect in the treatment of murine Pneumocystis pneumonia in CD4-depleted mice. This therapeutic effect is mediated through enhanced recruitment of CD8+ T cells and decreased apoptosis of lung T lymphocytes, with a preferential action on central memory CD8+ T lymphocytes. PMID:26483405

  15. The development of in vitro mutagenicity testing systems using T-lymphocytes

    SciTech Connect

    Albertini, R.J.

    1992-05-01

    This work has focused on the development of in vitro T-cell mutation assays. Conditions have been defined to measure the in vitro induction of mutations at the hypoxanthine-guanine phosphoribosyl transferase (hprt) locus in human T-lymphocytes. This assay is a parallel to our in vivo hprt assay, in that the same cells are utilized. However, the in vitro assay allows for carefully controlled dose response studies. 21 refs., 16 figs., 13 tabs.

  16. Inhibition of T-lymphocyte proliferation by cucurbitacins from Picrorhiza scrophulariaeflora.

    PubMed

    Smit, H F; van den Berg, A J; Kroes, B H; Beukelman, C J; Quarles van Ufford, H C; van Dijk, H; Labadie, R P

    2000-09-01

    Two cucurbitacin aglycons were isolated from the dried rhizomes of Picrorhiza scrophulariaeflora and were identified as 25-acetoxy-2,3, 16,20-tetrahydroxy-9-methyl-19-norlanosta-5,23-dien-22-one (picracin, 1) and 2,3,16,20,25-pentahydroxy-9-methyl-19-norlanosta-5, 23-dien-22-one (deacetylpicracin, 2). Both compounds inhibit mitogen-induced T-lymphocyte proliferation at an IC(50) value of 1 microM. PMID:11000045

  17. Impact of different concentrations of human recombinant growth hormone on T lymphocytes.

    PubMed

    Borrione, P; Grasso, L; Pautasso, M; Parisi, A; Quaranta, F; Ciminelli, E; Di Gianfrancesco, A; Di Luigi, L; Pigozzi, F

    2012-01-01

    The aim of the present study is to evaluate the effects induced by increasing concentrations of human recombinant growth hormone on T lymphocytes. Ten healthy volunteers and twelve subjects with symptomatic allergies were enrolled in the study. Peripheral blood mononuclear cells and purified T lymphocytes were cultured in the presence of graded concentrations of growth hormone. Following appropriate in vitro stimulations, the proportion of apoptotic T cells, the percentage of activated T lymphocyte subpopulations, the phytohemagglutinin responsiveness and the Th2 response were assessed by flow cytometry analysis. Moreover, in order to evaluate the phosphoinositol-3-kinase signaling pathway involvement, cells were also analyzed after treatment with LY294002. The treatment with different concentrations of growth hormone did not influence the activation pattern of un-stimulated T lymphocytes. On the contrary, growth hormone was able to modify the CD38/HLA-DR co-expression of T cells activated with phytohemoagglutinin. A different response was observed when samples obtained from healthy donors and from subjects with symptomatic allergies were analysed. Moreover, growth hormone treatment was able to increase the Th2 response in the samples obtained from healthy donors only. The results of the present study strongly support the hypothesis that growth hormone administration may play an important role in conditions of impaired/activated immune systems. The observation that growth hormone administration at high doses may reverse its effects and that it may promote a Th2-oriented response have significant clinical implications when considering the use of this hormone for artificially enhancing the physical performances of healthy athletes. PMID:22507321

  18. Distinct mechanisms of B and T lymphocyte accumulation generate tumor-draining lymph node hypertrophy.

    PubMed

    Habenicht, Lauren M; Albershardt, Tina C; Iritani, Brian M; Ruddell, Alanna

    2016-08-01

    Tumor-draining lymph nodes (TDLNs) often enlarge in human cancer patients and in murine tumor models, due to lymphocyte accumulation and lymphatic sinus growth. B lymphocytes within TDLNs can drive lymph node hypertrophy in response to tumor growth, however little is known about the mechanisms directing the preferential accumulation of B lymphocytes relative to T cells in enlarging TDLNs. To define why B and T lymphocytes accumulate in TDLNs, we quantified lymphocyte proliferation, apoptosis, entry, and exit in TDLNs versus contralateral non-TDLNs (NTDLNs) in a footpad B16-F10 melanoma mouse model. B and T lymphocyte proliferation and apoptosis were increased as the TDLNs enlarged, although relative rates were similar to those of NTDLNs. TDLN entry of B and T lymphocytes via high endothelial venules was also modestly increased in enlarged TDLNs. Strikingly, the egress of B cells was strongly reduced in TDLNs versus NTDLNs, while T cell egress was modestly decreased, indicating that regulation of lymphocyte exit from TDLNs is a major mechanism of preferential B lymphocyte accumulation. Surface sphingosine-1-phosphate receptor 1 (S1PR1) which binds S1P and signals lymphocyte egress, exhibited greater downregulation in B relative to T lymphocytes, consistent with preferential retention of B lymphocytes in TDLNs. TDLN lymphocytes did not activate surface CD69 expression, indicating a CD69-independent mechanism of downregulation of S1PR1. B and T cell trafficking via afferent lymphatics to enter TDLNs also increased, suggesting a pathway for accumulation of tumor-educated lymphocytes in TDLNs. These mechanisms regulating TDLN hypertrophy could provide new targets to manipulate lymphocyte responses to cancer. PMID:27622075

  19. Potassium currents inhibition by gambierol analogs prevents human T lymphocyte activation.

    PubMed

    Rubiolo, J A; Vale, C; Martín, V; Fuwa, H; Sasaki, M; Botana, L M

    2015-07-01

    Gambierol is a marine polycyclic ether toxin, produced along with ciguatoxin congeners by the dinoflagellate Gambierdiscus toxicus. We have recently reported that two truncated skeletal analogs of gambierol comprising the EFGH- and BCDEFGH-rings of the parent compound showed similar potency to gambierol on voltage-gated potassium channels (Kv) inhibition in neurons. Gambierol and its truncated analogs share the main crucial elements for biological activity, which are the C28=C29 double bond within the H-ring and the unsaturated side chain. Since Kv channels are critical for the regulation of calcium signaling, proliferation, secretion and migration in human T lymphocytes, we evaluated the activity of both the tetracyclic and heptacyclic analogs of gambierol on potassium currents in resting T lymphocyte and their effects on interleukin-2 (IL-2) release and gene expression in activated T lymphocytes. The results presented in this work clearly demonstrate that both truncated analogs of gambierol inhibit Kv channels present in resting T lymphocytes (Kv1.3) and prevented lymphocyte activation by concanavalin A. The main effects of the heptacyclic and tetracyclic analogs of gambierol in human T cells are: (1) inhibition of potassium channels in resting and concanavalin-activated T cells in the nanomolar range, (2) inhibition of IL-2 release from concanavalin-activated T cells and (3) negatively affect the expression of genes involved in cell proliferation and immune response observed in concanavalin-activated lymphocytes. These results together with the lack of toxicity in this cellular model, indicates that both analogs of gambierol have additional potential for the development of therapeutic tools in autoimmune diseases. PMID:25155189

  20. Distinct mechanisms of B and T lymphocyte accumulation generate tumor-draining lymph node hypertrophy

    PubMed Central

    Habenicht, Lauren M.; Albershardt, Tina C.; Iritani, Brian M.; Ruddell, Alanna

    2016-01-01

    ABSTRACT Tumor-draining lymph nodes (TDLNs) often enlarge in human cancer patients and in murine tumor models, due to lymphocyte accumulation and lymphatic sinus growth. B lymphocytes within TDLNs can drive lymph node hypertrophy in response to tumor growth, however little is known about the mechanisms directing the preferential accumulation of B lymphocytes relative to T cells in enlarging TDLNs. To define why B and T lymphocytes accumulate in TDLNs, we quantified lymphocyte proliferation, apoptosis, entry, and exit in TDLNs versus contralateral non-TDLNs (NTDLNs) in a footpad B16-F10 melanoma mouse model. B and T lymphocyte proliferation and apoptosis were increased as the TDLNs enlarged, although relative rates were similar to those of NTDLNs. TDLN entry of B and T lymphocytes via high endothelial venules was also modestly increased in enlarged TDLNs. Strikingly, the egress of B cells was strongly reduced in TDLNs versus NTDLNs, while T cell egress was modestly decreased, indicating that regulation of lymphocyte exit from TDLNs is a major mechanism of preferential B lymphocyte accumulation. Surface sphingosine-1-phosphate receptor 1 (S1PR1) which binds S1P and signals lymphocyte egress, exhibited greater downregulation in B relative to T lymphocytes, consistent with preferential retention of B lymphocytes in TDLNs. TDLN lymphocytes did not activate surface CD69 expression, indicating a CD69-independent mechanism of downregulation of S1PR1. B and T cell trafficking via afferent lymphatics to enter TDLNs also increased, suggesting a pathway for accumulation of tumor-educated lymphocytes in TDLNs. These mechanisms regulating TDLN hypertrophy could provide new targets to manipulate lymphocyte responses to cancer. PMID:27622075

  1. Anti-inflammatory effects of novel barbituric acid derivatives in T lymphocytes.

    PubMed

    Xu, Chenjia; Wyman, Arlene R; Alaamery, Manal A; Argueta, Shannon A; Ivey, F Douglas; Meyers, John A; Lerner, Adam; Burdo, Tricia H; Connolly, Timothy; Hoffman, Charles S; Chiles, Thomas C

    2016-09-01

    We have used a high throughput small molecule screen, using a fission yeast-based assay, to identify novel phosphodiesterase 7 (PDE7) inhibitors. One of the most effective hit compounds was BC12, a barbituric acid-based molecule that exhibits unusually potent immunosuppressive and immunomodulatory actions on T lymphocyte function, including inhibition of T cell proliferation and IL-2 cytokine production. BC12 treatment confers a >95% inhibition of IL-2 secretion in phytohaemagglutinin (PHA) plus phorbol-12-myristate-13-acetate (PMA) stimulated Jurkat T cells. The effect of BC12 on IL-2 secretion is not due to decreased cell viability; rather, BC12 blocks up-regulation of IL-2 transcription in activated T cells. BC12 also inhibits IL-2 secretion in human peripheral T lymphocytes stimulated in response to CD3/CD28 co-ligation or the combination of PMA and ionomycin, as well as the proliferation of primary murine T cells stimulated with PMA and ionomycin. A BC12 analog that lacks PDE7 inhibitory activity (BC12-4) displays similar biological activity, suggesting that BC12 does not act via PDE7 inhibition. To investigate the mechanism of inhibition of IL-2 production by BC12, we performed microarray analyses using unstimulated and stimulated Jurkat T cells in the presence or absence of BC12 or BC12-4. Our studies show these compounds affect the transcriptional response to stimulation and act via one or more shared targets to produce both anti-inflammatory and pro-stress effects. These results demonstrate potent immunomodulatory activity for BC12 and BC12-4 in T lymphocytes and suggest a potential clinical use as an immunotherapeutic to treat T lymphocyte-mediated diseases. PMID:27302770

  2. TLR Function in Murine CD4(+) T Lymphocytes and Their Role in Inflammation.

    PubMed

    Flaherty, Stephanie; Reynolds, Joseph M

    2016-01-01

    Toll-like receptor (TLR) signaling represents an evolutionary-conserved mechanism allowing for the rapid detection of broad molecular patterns that are common to different groups of pathogens. TLRs are traditionally associated with cells of the innate immune response where ligation of a TLR alone can lead to cellular activation and the initialization of an immune response. Cells of adaptive immunity, namely different classes of T and B lymphocytes, are also known to express a variety of TLRs. Conversely, the functional and signaling outcomes of TLRs are decidedly different in cells of the adaptive immune response. T lymphocytes generally have substantially lower TLR expression compared to innate cells, suggesting that TLRs function in a highly specialized capacity in this cell type. Certain TLRs act in a co-stimulatory capacity on T cells, amplifying activation only in the presence of simultaneous T-cell receptor engagement. However, the full array of TLR signaling events and outcomes in T lymphocytes remains poorly understood. Here, we describe a few methods for investigating the general function of TLRs on T lymphocytes in vitro and in vivo with an emphasis on the study of CD4(+) T cells. Most of these procedures can be adapted for the study of TLR signaling on other classes of lymphocytes as well. PMID:26803632

  3. Chemoattractant lymphokines specific for the helper/inducer T-lymphocyte subset.

    PubMed

    Berman, J S; Cruikshank, W W; Center, D M; Theodore, A C; Beer, D J

    1985-10-01

    The cellular content of T-lymphocyte-rich inflammatory sites is dependent in part on the in situ elaboration of chemoattractant factors. We have previously described three T-lymphocyte-specific chemoattractant lymphokines; a chemokinetic factor, lymphocyte chemoattractant factor (LCF, MW 56,000), and two distinct lymphocyte migration inhibitory factors (LyMIF75K, MW 75,000; and LyMIF35K, MW 35,000). These factors are produced by human T cells in response to antigen, concanavalin A, or histamine stimulation. In this communication, we report that LCF and LyMIF35K are produced by OKT8+ (suppressor/cytotoxic) and OKT4+ (helper/inducer) lymphocytes, respectively, and are selectively chemoattractant for the OKT4+ lymphocyte subset. LyMIF75K is produced by OKT4+ cells and inhibits both OKT4+ and OKT8+ lymphocyte migration. Production of LCF and LyMIF35K by infiltrating lymphocyte subsets may be one mechanism whereby unactivated helper/inducer T lymphocytes are selectively recruited to sites of inflammation. PMID:3161625

  4. Increased radiosensitivity of a subpopulation of T-lymphocyte progenitors from patients with Fanconi's anemia

    SciTech Connect

    Knox, S.J.; Wilson, F.D.; Greenberg, B.R.; Shifrine, M.; Rosenblatt, L.S.; Reeves, J.D.; Misra, H.

    1981-06-01

    In vitro radiation survival of peripheral blood T lymphocytes was studied in 15 clinically normal adults and 4 patients with Fanconi's anemia. Tritiated thymidine incorporation in a whole blood lymphocyte stimulation test (LST) and a newly developed whole blood T-lymphocyte colony assay were used to measure lymphocyte blastogenesis and colony formation in response to phytohemagglutinin (PHA) or concanavalin-A (Con-A) stimulation. Lymphocyte colony formation was found to be consistently more sensitive than the LST for detection of low-level radiation effects using both normal cells and lymphocytes from Fanconi's anemia patients. Lymphocytes from patients with Fanconi's anemia were significantly more sensitive to in vitro x irradiation than lymphocytes from clinically normal individuals as measured by their ability to divide when stimulated by PHA in the LST and colony formation assay. No significant difference in the radiosensitivity of the Con-A response was observed between the two groups. The PHA-responsive T-lymphocyte subpopulation in Fanconi's anemia patients appears to be intrinsically defective. The nature of this defect, significance in the disease process, and relevancy of these findings to the establishment of radiation protection standards are discussed.

  5. Increased radiosensitivity of a subpopulation ot T-lymphocyte progenitors from patients with Fanconi's anemia

    SciTech Connect

    Knox, S.J.; Wilson, F.D.; Greenberg, B.R.; Shifrine, M.; Rosenblatt, L.S.; Reeves, J.D.; Misra, H.

    1981-06-01

    In vitro radiation survival of peripheral blood T lymphocytes was studied in 15 clinically normal adults and 4 patients with Fanconi's anemia. Tritiated thymidine incorporation in a whole blood lymphocyte stimulation test (LST) and a newly developed whole blood T-lymphocyte colony assay were used to measure lymphocyte blastogenesis and colony formation in response to phytohemagglutinin (PHA) or concanavalin-A (Con-A) stimulation. Lymphocyte colony formation was found to be consistently more sensitive than the LST for detection of low-level radiation effects using both normal cells and lymphocytes from Fanconi's anemia patients. Lymphocytes from patients with Fanconi's anemia were significantly more sensitive to in vitro x-irradiation than lymphocytes from clinically normal individuals as measured by their ability to divide when stimulated by PHA in the LST (patients, D37 . 198 R; normals, D37 . 309 R, p . 0.057) and colony formation assay (patients, D37 . 53 R; normals, D37 . 109 R, p . 0.016). No significant difference in the radiosensitivity of the Con-A response was observed between the two groups. The PHA-responsive T-lymphocyte subpopulation in Fanconi's anemia patients appears to be intrinsically defective. The nature of this defect, significance in the disease process, and relevancy of these findings to the establishment of radiation protection standards are discussed.

  6. A unique CD8(+) T lymphocyte signature in pediatric type 1 diabetes.

    PubMed

    Hamel, Yamina; Mauvais, François-Xavier; Pham, Hang-Phuong; Kratzer, Roland; Marchi, Christophe; Barilleau, Émilie; Waeckel-Enée, Emmanuelle; Arnoux, Jean-Baptiste; Hartemann, Agnès; Cordier, Corinne; Mégret, Jerome; Rocha, Benedita; de Lonlay, Pascale; Beltrand, Jacques; Six, Adrien; Robert, Jean-Jacques; van Endert, Peter

    2016-09-01

    Human type 1 diabetes results from a destructive auto-reactive immune response in which CD8(+) T lymphocytes play a critical role. Given the intense ongoing efforts to develop immune intervention to prevent and/or cure the disease, biomarkers suitable for prediction of disease risk and progress, as well as for monitoring of immunotherapy are required. We undertook separate multi-parameter analyses of single naïve and activated/memory CD8(+) T lymphocytes from pediatric and adult patients, with the objective of identifying cellular profiles associated with onset of type 1 diabetes. We observe global perturbations in gene and protein expression and in the abundance of T cell populations characterizing pediatric but not adult patients, relative to age-matched healthy individuals. Pediatric diabetes is associated with a unique population of CD8(+) T lymphocytes co-expressing effector (perforin, granzyme B) and regulatory (transforming growth factor β, interleukin-10 receptor) molecules. This population persists after metabolic normalization and is especially abundant in children with high titers of auto-antibodies to glutamic acid decarboxylase and with elevated HbA1c values. These findings highlight striking differences between pediatric and adult type 1 diabetes, indicate prolonged large-scale perturbations in the CD8(+) T cell compartment in the former, and suggest that CD8(+)CD45RA(-) T cells co-expressing effector and regulatory factors are of interest as biomarkers in pediatric type 1 diabetes. PMID:27318739

  7. Differential expression of three T lymphocyte-activating CXC chemokines by human atheroma-associated cells

    PubMed Central

    Mach, François; Sauty, Alain; Iarossi, Albert S.; Sukhova, Galina K.; Neote, Kuldeep; Libby, Peter; Luster, Andrew D.

    1999-01-01

    Activated T lymphocytes accumulate early in atheroma formation and persist at sites of lesion growth and rupture, suggesting that they may play an important role in the pathogenesis of atherosclerosis. Moreover, atherosclerotic lesions contain the Th1-type cytokine IFN-γ, a potentiator of atherosclerosis. The present study demonstrates the differential expression of the 3 IFN-γ–inducible CXC chemokines — IFN-inducible protein 10 (IP-10), monokine induced by IFN-γ (Mig), and IFN-inducible T-cell α chemoattractant (I-TAC) — by atheroma-associated cells, as well as the expression of their receptor, CXCR3, by all T lymphocytes within human atherosclerotic lesions in situ. Atheroma-associated endothelial cells (ECs), smooth muscle cells (SMCs), and macrophages (MØ) all expressed IP-10, whereas Mig and I-TAC were mainly expressed in ECs and MØ, as detected by double immunofluorescence staining. ECs of microvessels within lesions also expressed abundant I-TAC. In vitro experiments supported these results and showed that IL-1β, TNF-α, and CD40 ligand potentiated IP-10 expression from IFN-γ–stimulated ECs. In addition, nitric oxide (NO) treatment decreased IFN-γ induction of IP-10. Our findings suggest that the differential expression of IP-10, Mig, and I-TAC by atheroma-associated cells plays a role in the recruitment and retention of activated T lymphocytes observed within vascular wall lesions during atherogenesis. PMID:10525042

  8. 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

  9. PD-1 function in apoptosis of T lymphocytes in canine visceral leishmaniasis.

    PubMed

    Chiku, Vanessa Marim; Silva, Kathlenn Liezbeth Oliveira; de Almeida, Breno Fernando Martins; Venturin, Gabriela Lovizutto; Leal, Aline Aparecida Correa; de Martini, Cleber Costa; de Rezende Eugênio, Flavia; Dos Santos, Paulo Sergio Patto; de Lima, Valéria Marçal Felix

    2016-08-01

    Dogs infected with Leishmania infantum have a reduced number of T lymphocytes. PD-1 (Programmed cell death 1) a new member of the B7-CD28 family that is expressed by immune cells, and its binding to PD-L1 (CD274) or PD-L2 (CD273) induces the deactivation or apoptosis of T cells. This study aimed to evaluate the expression of PD-1 and its ligands, as well as blocking in the induction of apoptosis in T lymphocytes, TNF-α, IL-4 and nitric oxide production by leucokocytes from PBMC and spleen and the parasite load in dogs with visceral leishmaniasis (VL). Our results showed that the expression of PD1 and its ligands was increased in CD3(+) T cells and CD21(+) B lymphocytes within the peripheral blood and splenic mononuclear cells of dogs with VL. In peripheral blood monocytes, only PD-1 ligands exhibited increased expression; however, in spleen macrophages, increased expression of both PD-1 and its ligands was observed. Levels of apoptosis in peripheral blood and splenic T lymphocytes were higher in dogs with VL compared to healthy dogs. Blocking monoclonal antibodies to PD-1 and its ligands in the culture of mononuclear cells from the peripheral blood and spleen decreased the amount of CD3(+) T lymphocyte apoptosis. The concentration of nitric oxide, TNF-α and IL-4 increased in the culture supernatants of peripheral blood mononuclear cells treated with a blocking monoclonal antibody against PD-1. The TNF-α concentration increased in the culture supernatants of splenic cells following all treatments with antibodies blocking PD-1 and its ligands; however, the amount of IL-4 increased only in the presence of a PD-1 blocking agent. Treatment with a PD-1 blocking monoclonal antibody in the mononuclear peripheral blood of dogs with VL reduced the parasite burden while increased TNF-α. We conclude that in canine visceral leishmaniasis, PD-1 and its ligands are involved in the induction of T lymphocyte apoptosis and in regulating the production of nitric oxide, TNF

  10. Differential Dynamics of CD4+ and CD8+ T-Lymphocyte Proliferation and Activation in Acute Simian Immunodeficiency Virus Infection

    PubMed Central

    Kaur, Amitinder; Hale, Corrina L.; Ramanujan, Saroja; Jain, Rakesh K.; Johnson, R. Paul

    2000-01-01

    Although lymphocyte turnover in chronic human immunodeficiency virus and simian immunodeficiency virus (SIV) infection has been extensively studied, there is little information on turnover in acute infection. We carried out a prospective kinetic analysis of lymphocyte proliferation in 13 rhesus macaques inoculated with pathogenic SIV. A short-lived dramatic increase in circulating Ki-67+ lymphocytes observed at 1 to 4 weeks was temporally related to the onset of SIV replication. A 5- to 10-fold increase in Ki-67+ CD8+ T lymphocytes and a 2- to 3-fold increase in Ki-67+ CD3− CD8+ natural killer cells accounted for >85% of proliferating lymphocytes at peak proliferation. In contrast, there was little change in the percentage of Ki-67+ CD4+ T lymphocytes during acute infection, although transient increases in Ki-67− and Ki-67+ CD4+ T lymphocytes expressing CD69, Fas, and HLA-DR were observed. A two- to fourfold decline in CD4+ T lymphocytes expressing CD25 and CD69 was seen later in SIV infection. The majority of Ki-67+ CD8+ T lymphocytes were phenotypically CD45RA− CD49dhi Fashi CD25− CD69− CD28− HLA-DR− and persisted at levels twofold above baseline 6 months after SIV infection. Increased CD8+ T-lymphocyte proliferation was associated with cell expansion, paralleled the onset of SIV-specific cytotoxic T-lymphocyte activity, and had an oligoclonal component. Thus, divergent patterns of proliferation and activation are exhibited by CD4+ and CD8+ T lymphocytes in early SIV infection and may determine how these cells are differentially affected in AIDS. PMID:10954541

  11. Local production of the chemokines CCL5 and CXCL10 attracts CD8+ T lymphocytes into esophageal squamous cell carcinoma

    PubMed Central

    Ping, Yu; Wang, Liping; Chen, Xinfeng; Wang, Dan; Cao, Ling; Zhao, Song; Li, Bing; Kalinski, Pawel; Thorne, Stephen H.; Zhang, Bin; Zhang, Yi

    2015-01-01

    Esophageal squamous cell carcinoma (ESCC) is a very common malignant tumor with poor prognosis in China. Chemokines secreted by tumors are pivotal for the accumulation of CD8+ T lymphocytes within malignant lesions in several types of cancers, but the exact mechanism underlying CD8+ T lymphocyte homing is still unknown in ESCC. In this study, we revealed that, compared with marginal tissues, the expression of both chemokine (C-C motif) ligand 5 (CCL5) and (C-X-C motif) ligand 10 (CXCL10) was upregulated in ESCC tissues. CCL5 expression was positively associated with the overall survival of patients. Meanwhile, RT-PCR data showed that the expression of CCL5 and CXCL10 was positively correlated with the local expressions of the CD8+ T lymphocyte markers (CD8 and Granzyme B) in tumor tissues. Correspondingly, CD8+ T lymphocytes were more frequently CCR5- and CXCR3-positive in tumor than in peripheral blood. Transwell analysis showed both CCL5 and CXCL10 were important for the chemotactic movement of CD8+ T lymphocytes. Our data indicate that CCL5 and CXCL10 serve as the key chemokines to recruit CD8+ T lymphocytes into ESCC tissue and may play a role in patient survival. PMID:26317795

  12. Thinning of the RPE and choroid associated with T lymphocyte recruitment in aged and light-challenged mice

    PubMed Central

    Camelo, Serge; Calippe, Bertrand; Lavalette, Sophie; Dominguez, Elisa; Hur, Justine; Devevre, Estelle; Guillonneau, Xavier; Sennlaub, Florian

    2015-01-01

    Purpose Thinning of the RPE and the underlying vascular layer, the choroid, is observed with age in many human eye disorders. The reasons for this thinning are ill-defined. Here, we highlight the possible role of T lymphocyte recruitment in choroidoretinal thinning in aged and light-challenged mice. Methods In age and light challenge models, we measured chemokine concentrations using enzyme-linked immunosorbent assay and used flow cytometry to characterize lymphocyte populations. We quantified thinning in eye immunosections and RPE65 expression using quantitative PCR. Results Age and light challenge led to increased levels of the lymphotactic protein CXCL10 alone (aging) or in conjunction with CXCL9 (light challenge). Increased numbers of CD3+ T lymphocytes, most of them CD8+ cytotoxic T lymphocytes, were also observed in the choroid and retina of old mice and following light challenge. Influx of T lymphocytes was associated with RPE and choroidal thinning and diminished expression of RPE65 mRNA, an essential enzyme of the visual cycle. Conclusions The observations from this study suggest that cytotoxic CD8+ T lymphocytes might participate in choroidal and RPE degeneration and that modulation of T lymphocyte recruitment might be a novel strategy to reduce choroidoretinal dysfunctions observed with age and following photo-oxidative stress. PMID:26392743

  13. Cell surface Glut1 levels distinguish human CD4 and CD8 T lymphocyte subsets with distinct effector functions

    PubMed Central

    Cretenet, Gaspard; Clerc, Isabelle; Matias, Maria; Loisel, Severine; Craveiro, Marco; Oburoglu, Leal; Kinet, Sandrina; Mongellaz, Cédric; Dardalhon, Valérie; Taylor, Naomi

    2016-01-01

    CD4 and CD8 T lymphocyte activation requires the generation of sufficient energy to support new biosynthetic demands. Following T cell receptor (TCR) engagement, these requirements are met by an increased glycolysis, due, at least in part, to induction of the Glut1 glucose transporter. As Glut1 is upregulated on tumor cells in response to hypoxia, we assessed whether surface Glut1 levels regulate the antigen responsiveness of human T lymphocytes in both hypoxic and atmospheric oxygen conditions. Notably, Glut1 upregulation in response to TCR stimulation was significantly higher in T lymphocytes activated under hypoxic as compared to atmospheric oxygen conditions. Furthermore, TCR-stimulated human T lymphocytes sorted on the basis of Glut1-Lo and Glut1-Hi profiles maintained distinct characteristics, irrespective of the oxygen tension. While T cells activated in hypoxia divided less than those activated in atmospheric oxygen, Glut1-Hi lymphocytes exhibited increased effector phenotype acquisition, augmented proliferation, and an inverted CD4/CD8 ratio in both oxygen conditions. Moreover, Glut1-Hi T lymphocytes exhibited a significantly enhanced ability to produce IFN-γ and this secretion potential was completely dependent on continued glycolysis. Thus, Glut1 surface levels identify human T lymphocytes with distinct effector functions in both hypoxic and atmospheric oxygen tensions. PMID:27067254

  14. Mycobacterium tuberculosis induces apoptosis in gamma/delta T lymphocytes from patients with advanced clinical forms of active tuberculosis.

    PubMed Central

    Duarte, R; Kindlelán, J M; Carracedo, J; Sánchez-Guijo, P; Ramírez, R

    1997-01-01

    Antigens from inactivated Mycobacterium tuberculosis H37Ra induce activation in a subpopulation of gamma/delta (gamma/delta) T lymphocytes in a manner that resembles that of superantigens from alpha/beta T cells. After culture in vitro with H37Ra proteins, gamma/delta T lymphocytes from patients with advanced clinical forms of active tuberculosis (ACF-TBC) display cytotoxic activity against homotypic target cells exposed to H37Ra. Cytotoxicity by gamma/delta T lymphocytes from ACF-TBC patients occurs in a range similar to that observed in healthy subjects. Following activation, H37Ra-stimulated gamma/delta T lymphocytes from healthy subjects did proliferate in the presence of exogenous recombinant human interleukin 2. However, under the same conditions, gamma/delta T lymphocytes from ACF-TBC patients not only did not proliferate but died by apoptosis. These results suggest that in gamma/delta T lymphocytes from patients with ACF-TBC, antigens from M. tuberculosis may induce cell activation that leads to apoptotic cell death. PMID:9008275

  15. 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

  16. TSC-22 Promotes Interleukin-2-Deprivation Induced Apoptosis in T-Lymphocytes.

    PubMed

    Pépin, Aurélie; Espinasse, Marie-Alix; Latré de Laté, Perle; Szely, Natacha; Pallardy, Marc; Biola-Vidamment, Armelle

    2016-08-01

    Originally described as a TGF-β-inducible gene, tsc-22 (Transforming growth factor-beta Stimulated Clone 22) encodes a transcriptional regulator affecting biological processes such as cell growth, differentiation, or apoptosis. Along with GILZ (Glucocorticoid-Induced Leucine Zipper), TSC-22 belongs to the evolutionary conserved TSC-22 Domain family. We previously showed that, in T-lymphocytes, GILZ expression was induced upon IL-2 withdrawal, delaying apoptosis through down-regulation of the pro-apoptotic protein BIM expression. The aim of this work was then to elucidate the respective roles of GILZ and TSC-22 upon IL-2 deprivation-induced apoptosis. We report here that these two highly homologous genes are concomitantly expressed in most human tissues and in primary T-lymphocytes and that expression of TSC-22 promotes T-lymphocytes apoptosis by inhibiting GILZ functions. Indeed, we demonstrated that TSC-22 expression in the murine lymphoid CTLL-2 cell line promoted IL-2 deprivation-induced apoptosis. BIM expression and caspases-9 and -3 activities were markedly increased in TSC-22 expressing clones compared to control clones. Analysis of GILZ expression revealed that TSC-22 prevented the induction of the GILZ protein upon IL-2 deprivation, by inhibiting gilz mRNA transcription. These results suggested that TSC-22 could counteract the protective effect of GILZ on IL-2-deprivation-induced apoptosis. Moreover, TSC-22-induced inhibition of GILZ expression was also found in CTLL-2 cells treated with glucocorticoids or TGF-β. In the human NKL cell line deprived of IL-2, TSC-22 showed the same effect and thus may represent a potent repressor of GILZ expression in IL-2-dependent cells, independently of the cell type, or the stimulus, leading to an increase of IL-2-deprived T-cells apoptosis. J. Cell. Biochem. 117: 1855-1868, 2016. © 2016 Wiley Periodicals, Inc. PMID:26752201

  17. Alterations in the T-lymphocyte subpopulation in patients with rhinoscleroma.

    PubMed Central

    Berron, P; Berron, R; Ortiz-Ortiz, L

    1988-01-01

    T-lymphocyte subpopulations were studied in a group of patients with rhinoscleroma due to Klebsiella rhinoscleromatis. The data demonstrated that these patients had a significantly greater number of T-suppressor/cytotoxic lymphocytes than did clinically healthy individuals. This finding correlated with a diminished response to the T-cell mitogen concanavalin A. The evidence indicated that the T-cell response of these patients was decreased and may reflect the host's response to the bacterial invader, thus explaining the chronicity of the disease. PMID:2968362

  18. T Lymphocyte Activation Threshold and Membrane Reorganization Perturbations in Unique Culture Model

    NASA Technical Reports Server (NTRS)

    Adams, C. L.; Sams, C. F.

    2000-01-01

    Quantitative activation thresholds and cellular membrane reorganization are mechanisms by which resting T cells modulate their response to activating stimuli. Here we demonstrate perturbations of these cellular processes in a unique culture system that non-invasively inhibits T lymphocyte activation. During clinorotation, the T cell activation threshold is increased 5-fold. This increased threshold involves a mechanism independent of TCR triggering. Recruitment of lipid rafts to the activation site is impaired during clinorotation but does occur with increased stimulation. This study describes a situation in which an individual cell senses a change in its physical environment and alters its cell biological behavior.

  19. Essential role of T lymphocytes in the development of allergen-driven airway hyperresponsiveness.

    PubMed

    Gelfand, E W

    1998-01-01

    Asthma now affects more than 15 million Americans and results in significant expenditure of resources. Despite intensive investigation into the pathogenesis of asthma, debate continues over which cells or which mediators are the primary contributors to the disease. Increasingly, asthma is recognized as a chronic, inflammatory disease. T lymphocytes, T-cell derived cytokines, and eosinophils play major roles in the initiation and perpetuation of the inflammatory response. Animal models have enabled us to link directly T cells with eosinophilic inflammation of the airways, providing new insights into pathogenesis and novel opportunities for therapeutic interventions. PMID:9876776

  20. [Effect of synthetic beta-carotene on the formation of cytolytic T-lymphocytes].

    PubMed

    Efimov, S A; Vakulova, L A; Rytenko, A N; Samokhvalov, G I; Sergeev, I M

    1984-06-01

    The effect of intraperitoneal injection of beta-carotene in different doses on the formation of cytolytic T lymphocytes (CTL) in a one-way mixed lymphocyte culture (MLC) of allogeneic mice was studied. The maximal cytotoxic activity of lymphocytes was attained in the MLC with splenocytes of mice which received 10 mg/kg beta-carotene 6 days before experimentation. The correlation was studied between the beta-carotene ability to stimulate CTL formation and antineoplastic activity. It was discovered that injection of beta-carotene in doses and times provoking maximal CTL induction had no effect on the animals' lifespan and the size of transplanted sarcoma 180. PMID:6234949

  1. Monoclonal antibodies to antigens on human neutrophils, activated T lymphocytes, and acute leukemia blast cells

    SciTech Connect

    Miterev, G.Yu.; Burova, G.F.; Puzhitskaya, M.S.; Danilevich, S.V.; Bulycheva, T.I.

    1987-11-01

    The authors describe the production of two mouse hybridomas secreting monoclonal antibodies to antigenic determinants of the surface membranes of human neutrophils, activated T lymphocytes, and acute leukemic blast cells. The degree of lymphocyte stimulation was estimated from incorporation of /sup 3/H-thymidine with parallel microculture. Monoclonal antibodies of supernatants of hybridoma cultures shown here reacted in both immunofluorescence test and cytotoxicity test with surface membrane antigens on the majority of neutrophils and PHA-activated peripheral blood lymphocytes from healthy subjects, but did not give positive reactions with unactivated lymphocytes, adherent monocytes, erythrocytes, and alloantigen-stimulated lymphocytes.

  2. Evaluation of oral Lanzhou lamb rotavirus vaccine via passive transfusion with CD4(+)/CD8(+) T lymphocytes.

    PubMed

    Du, Jialiang; Lan, Zhiling; Liu, Yueyue; Liu, Yan; Yu, Qingchuan; Li, Yanchao; Guo, Tai

    2016-06-01

    Lanzhou Lamb derived Rotavirus (RV) Vaccine (namely LLR) for children is only used in China. Since there were no reports on evaluation of LLR, even the data of phase IV clinical trial, we proceed the evaluation of LLR through focusing on T-cell to investigate whether LLR could induce the potential function involving in protection as a vaccine. Four groups of nude mice were transfused with CD4(+)/CD8(+) T-cells isolated from LLR-immunized (primed) and LLR-unimmunized (naïve) mice via intraperitonea (i.p.) respectively. Consequently, the adoption mice were challenged with mice-origin wild rotavirus EDIM (Epizootic Diarrhea of Infant Mice) by intragastric administration. Series of fecal/serum samples were collected and viral shedding, then serum IgA/IgG and secreted IgA were assayed. Compared to the mice transfused with T lymphocytes from naïve mice, the nude mice transfused with CD4(+) T lymphocytes from primed mice induce fecal and serum IgA increasing more rapidly, and have a shorter duration of virus shedding too. Whereas, no significant difference in virus clearance was found between the mice transfused with CD8(+) T lymphocytes isolated from primed and naïve mice. Therefore, we cleared the distinct roles of transfused CD4(+)/CD8(+) T lymphocytes for rotavirus clearance in nude mice, that the viral clearance conducted by CD4(+) T lymphocytes. Meanwhile, it has ability to help induction of LLR specific immunogenicity. Comparing with the transfusion of cell from primed and naïve mice, LLR can induce CD4(+) T lymphocytes memory which is a potential index to reflect the immunogenicity and protection, while CD8(+) T lymphocytes remove rotavirus by CTL with little memory ability. PMID:27025573

  3. Basal shuttle of NF-κB/IκBα in resting T lymphocytes regulates HIV-1 LTR dependent expression

    PubMed Central

    Coiras, Mayte; López-Huertas, María Rosa; Rullas, Joaquín; Mittelbrunn, Maria; Alcamí, José

    2007-01-01

    Background In HIV-infected T lymphocytes, NF-κB/Rel transcription factors are major elements involved in the activation of LTR-dependent transcription from latency. Most NF-κB heterodimer p65/p50 is sequestered as an inactive form in the cytoplasm of resting T lymphocytes via its interaction with IκB inhibitors. In these cells, both absolute HIV latency and low level ongoing HIV replication have been described. These situations could be related to differences in the balance between NF-κB and IκBα ratio. Actually, control of IκBα by cellular factors such as Murr-1 plays a critical role in maintaining HIV latency in unstimulated T lymphocytes. Formerly, our group demonstrated the presence of nuclear IκBα in T cells after PMA activation. Now we attempt to determine the dynamics of NF-κB/IκBα nucleocytosolic transport in absence of activation as a mechanism to explain both the maintenance of latency and the existence of low level ongoing HIV replication in resting CD4+ T lymphocytes. Results and conclusion We show that the inhibition of the nuclear export by leptomycin B in resting CD4+ T cells resulted in nuclear accumulation of both IκBα and p65/RelA, as well as formation of NF-κB/IκBα complexes. This proves the existence of a rapid shuttling of IκBα between nucleus and cytosol even in absence of cellular activation. The nuclear accumulation of IκBα in resting CD4+ T lymphocytes results in inhibition of HIV-LTR dependent transcription as well as restrains HIV replication in CD4+ T lymphocytes. On the other hand, basal NF-κB activity detected in resting CD4+ T lymphocytes was related to low level HIV replication in these cells. PMID:17686171

  4. In vivo protection of activated Tyr22-dihydrofolate reductase gene-modified canine T lymphocytes from methotrexate

    PubMed Central

    Gori, Jennifer L.; Beard, Brian C.; Williams, Nathaniel P.; Ironside, Christina; Swanson, Debra; McIvor, R. Scott; Kiem, HP

    2013-01-01

    Background Nonmyeloablative allogeneic hematopoietic stem cell (HSC) transplantation can cure malignant and nonmalignant diseases affecting the hematopoietic system, such as severe combined immunodeficiencies, aplastic anemia and hemoglobinopathies. Although nonmyeloablative is favored over myeloablative transplantation for many patients, graft rejection remains problematic. One strategy to decrease rejection is to protect donor activated T cells in the graft from methotrexate (MTX) by genetically modifying the cells to express MTX-resistant dihydrofolate reductase (Tyr22-DHFR), leaving the immunosuppressive effects of MTX to act solely on activated host T lymphocytes, shifting the balance to favor allogeneic engraftment. Methods To evaluate MTX resistance of Tyr22-DHFR+ T lymphocytes in vivo, we transplanted dogs with autologous CD34+ cells modified with YFP and DHFR-GFP lentivirus vectors. Dogs were then treated with a standard MTX regimen (days 1, 3, 6, and 11) following immune activation with a foreign antigen as a surrogate assay to mimic early transplantation. Results DHFR-GFP+ gene marking was maintained in CD3+CD25+ and CD4+ T lymphocytes after MTX treatment while the level of T lymphocytes that expressed only a fluorescent reporter (YFP+) decreased. These data show that Tyr22-DHFR expression protects T lymphocytes from MTX toxicity in dogs, highlighting a clinically relevant application for preserving donor T lymphocytes during post transplantation immunosuppression. Conclusions These findings have implications for clinical translation of MTX-resistant T cells to facilitate engraftment of allogeneic cells following nonmyeloablative conditioning and minimize the risk of rejection. In summary, Tyr22-DHFR expression in T lymphocytes provides chemoprotection from MTX-mediated elimination in the context of immune activation in vivo. PMID:23666780

  5. CD8+ T lymphocyte expansion, proliferation and activation in dengue fever.

    PubMed

    de Matos, Andréia Manso; Carvalho, Karina Inacio; Rosa, Daniela Santoro; Villas-Boas, Lucy Santos; da Silva, Wanessa Cardoso; Rodrigues, Célia Luiza de Lima; Oliveira, Olímpia Massae Nakasone Peel Furtado; Levi, José Eduardo; Araújo, Evaldo Stanislau Affonso; Pannuti, Claudio Sergio; Luna, Expedito José Albuquerque; Kallas, Esper George

    2015-02-01

    Dengue fever induces a robust immune response, including massive T cell activation. The level of T cell activation may, however, be associated with more severe disease. In this study, we explored the level of CD8+ T lymphocyte activation in the first six days after onset of symptoms during a DENV2 outbreak in early 2010 on the coast of São Paulo State, Brazil. Using flow cytometry we detected a progressive increase in the percentage of CD8+ T cells in 74 dengue fever cases. Peripheral blood mononuclear cells from 30 cases were thawed and evaluated using expanded phenotyping. The expansion of the CD8+ T cells was coupled with increased Ki67 expression. Cell activation was observed later in the course of disease, as determined by the expression of the activation markers CD38 and HLA-DR. This increased CD8+ T lymphocyte activation was observed in all memory subsets, but was more pronounced in the effector memory subset, as defined by higher CD38 expression. Our results show that most CD8+ T cell subsets are expanded during DENV2 infection and that the effector memory subset is the predominantly affected sub population. PMID:25675375

  6. The pyrimidin analogue cyclopentenyl cytosine induces alloantigen-specific non-responsiveness of human T lymphocytes

    PubMed Central

    Nikolaeva, N; Bemelman, F J; Yong, S-L; Verschuur, A; van Lier, R A W; ten Berge, I J M

    2008-01-01

    Cyclopentenyl cytosine (CPEC) has been shown to induce apoptosis in human T lymphoblastic cell lines and T cells from leukaemia patients. In this study we have addressed the question of whether CPEC is able to decrease proliferation and effector functions of human alloresponsive T lymphocytes and induce T cell anergy. The proliferative capacity of human peripheral blood mononuclear cells in response to allogeneic stimulation was measured by 5,6-carboxy-succinimidyl-diacetate-fluorescein-ester staining. Flow cytometric analysis was performed using surface CD4, CD8, CD25, CD103 and intracellular perforin, granzyme A, granzyme B, caspase-3 and forkhead box P3 (FoxP3) markers. The in vivo immunosuppressive capacity was tested in a murine skin graft model. Addition of CPEC at a concentration of 20 nM strongly decreased the expansion and cytotoxicity of alloreactive T cells. Specific restimulation in the absence of CPEC showed that the cells became anergic. The drug induced caspase-dependent apoptosis of alloreactive T lymphocytes. Finally, CPEC increased the percentage of CD25high FoxP3+ CD4+ and CD103+ CD8+ T cells, and potentiated the effect of rapamycin in increasing the numbers of alloreactive regulatory T cells. Treatment with CPEC of CBA/CA mice transplanted with B10/Br skin grafts significantly prolonged graft survival. We conclude that CPEC inhibits proliferation and cytotoxicity of human alloreactive T cells and induces alloantigen non-responsiveness in vitro. PMID:18062797

  7. Spatial Interplay between Polycomb and Trithorax Complexes Controls Transcriptional Activity in T Lymphocytes.

    PubMed

    Onodera, Atsushi; Tumes, Damon J; Watanabe, Yukiko; Hirahara, Kiyoshi; Kaneda, Atsushi; Sugiyama, Fumihiro; Suzuki, Yutaka; Nakayama, Toshinori

    2015-11-01

    Trithorax group (TrxG) and Polycomb group (PcG) proteins are two mutually antagonistic chromatin modifying complexes, however, how they together mediate transcriptional counter-regulation remains unknown. Genome-wide analysis revealed that binding of Ezh2 and menin, central members of the PcG and TrxG complexes, respectively, were reciprocally correlated. Moreover, we identified a developmental change in the positioning of Ezh2 and menin in differentiated T lymphocytes compared to embryonic stem cells. Ezh2-binding upstream and menin-binding downstream of the transcription start site was frequently found at genes with higher transcriptional levels, and Ezh2-binding downstream and menin-binding upstream was found at genes with lower expression in T lymphocytes. Interestingly, of the Ezh2 and menin cooccupied genes, those exhibiting occupancy at the same position displayed greatly enhanced sensitivity to loss of Ezh2. Finally, we also found that different combinations of Ezh2 and menin occupancy were associated with expression of specific functional gene groups important for T cell development. Therefore, spatial cooperative gene regulation by the PcG and TrxG complexes may represent a novel mechanism regulating the transcriptional identity of differentiated cells. PMID:26324324

  8. The effect of stem cell from human exfoliated deciduous teeth on T lymphocyte proliferation

    PubMed Central

    Alipour, Razieh; Adib, Minoo; Hashemi-Beni, Batool; Sadeghi, Farzaneh

    2014-01-01

    Background: Mesenchymal stem cells (MSC), a specific type of adult tissue stem cell; have the immunosuppressive effects that make them valuable targets for regenerative medicine and treatment of many human illnesses. Hence, MSC have been the subject of numerous studies. The classical source of MSC is adult bone marrow (BM). Due to many shortcomings of harvesting MSC from BM, finding the alternative sources for MSC is an urgent. Stem cells from human exfoliated deciduous teeth (SHED) are relative new MSC populations that fulfill these criteria but their potential immunosuppressive effect has not been studied enough yet. Thus, in this work the effect of SHED on the proliferation of in vitro activated T lymphocytes were explored. Materials and Methods: In this study, both mitogen and alloantigen activated T cells were cultured in the presence of different numbers of SHED. In some co-cultures, activated T cells were in direct contact to MSCs and in other co-cultures; they were separated from SHED by a permeable membrane. In all co-cultures, the proliferation of T cells was measured by ELISA Bromodeoxyuridine proliferation assay. Results: In general, our results showed that SHED significantly suppress the proliferation of activated T cells in a dose-dependent manner. Moreover, the suppression was slightly stronger when MSCs were in physical contact to activated T cells. Conclusion: This study showed that SHED likewise other MSC populations can suppress the activation of T lymphocytes, which can be used instead of BM derived MSCs in many investigational and clinical applications. PMID:25337532

  9. 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

    2016-04-01

    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 (TH) 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. PMID:26479950

  10. Antitumor activity of cytotoxic T lymphocytes engineered to target vascular endothelial growth factor receptors

    NASA Astrophysics Data System (ADS)

    Niederman, Thomas M. J.; Ghogawala, Zoher; Carter, Bob S.; Tompkins, Hillary S.; Russell, Margaret M.; Mulligan, Richard C.

    2002-05-01

    The demonstration that angiogenesis is required for the growth of solid tumors has fueled an intense interest in the development of new therapeutic strategies that target the tumor vasculature. Here we report the development of an immune-based antiangiogenic strategy that is based on the generation of T lymphocytes that possess a killing specificity for cells expressing vascular endothelial growth factor receptors (VEGFRs). To target VEGFR-expressing cells, recombinant retroviral vectors were generated that encoded a chimeric T cell receptor comprised of VEGF sequences linked to intracellular signaling sequences derived from the chain of the T cell receptor. After transduction of primary murine CD8 lymphocytes by such vectors, the transduced cells were shown to possess an efficient killing specificity for cells expressing the VEGF receptor, Flk-1, as measured by in vitro cytotoxicity assays. After adoptive transfer into tumor-bearing mice, the genetically modified cytotoxic T lymphocytes strongly inhibited the growth of a variety of syngeneic murine tumors and human tumor xenografts. An increased effect on in vivo tumor growth inhibition was seen when this therapy was combined with the systemic administration of TNP-470, a conventional angiogenesis inhibitor. The utilization of the immune system to target angiogenic markers expressed on tumor vasculature may prove to be a powerful means for controlling tumor growth.

  11. On-line studies of activation events in primary human T lymphocytes.

    PubMed

    Bental, M; Deutsch, C

    1994-04-01

    In this paper, we review our NMR studies of human peripheral blood T lymphocytes. These studies focus on the physiological and biochemical alterations accompanying cell cycle progression. In particular, we have characterized phosphorus metabolism, glucose utilization and lactate production, and pH regulation using 31P, 13C, and 19F NMR, respectively. These studies required developing new methods for monitoring on-line stimulation of quiescent T cells under sterile, physiological conditions (i.e., CO2/HCO3- buffer, 37 degrees C) for prolonged periods of time. A perfusion system optimized for T lymphocytes inside agarose beads is described. In addition, custom-designed 19F NMR pH indicators were synthesized, characterized, and used to determine intracellular pH in quiescent lymphocytes, stimulated lymphocytes, and lymphocytes undergoing the G0-G1 transition. These unique molecular probes are described in detail. Finally, the physiological relevance of our findings regarding carbon metabolism and pH regulation is considered in the context of mitogenesis. PMID:8069534

  12. T lymphocyte-derived TNF and IFN-γ repress HFE expression in cancer cells.

    PubMed

    Reuben, Alexandre; Godin-Ethier, Jessica; Santos, Manuela M; Lapointe, Réjean

    2015-06-01

    The immune system and tumors are closely intertwined initially upon tumor development. During this period, tumors evolve to promote self-survival through immune escape, including by targeting crucial components involved in the presentation of antigens to the immune system in order to avoid recognition. Accordingly, components involved in MHC I presentation of tumor antigens are often mutated and down-regulated targets in tumors. On the other hand, the immune system has been shown to influence tumors through production of immunosuppressive cytokines, recruitment and polarization of cells favoring or impeding tumor escape or through production of anti-tumor cytokines promoting tumor rejection. We previously discovered that the hemochromatosis protein HFE, a negative regulator of iron absorption, dampens classical MHC I antigen presentation. In this study, we evaluated the impact of activated T lymphocytes purified from peripheral blood mononuclear cells (PBMC) on HFE expression in tumor cell lines. We co-cultured tumor cell lines from melanoma, lung, and kidney cancers with anti-CD3-activated PBMC and established that HFE expression is increased in tumor cell lines compared to healthy tissues, whilst being down-regulated significantly upon exposure to activated PBMC. HFE down-regulation was mediated by both CD4 and CD8 T lymphocytes, through production of soluble mediators, namely TNF and IFN-γ. These results suggest that the immune system may modulate tumor HFE expression in inflammatory conditions in order to regulate MHC I antigen presentation and promote tumor clearance. PMID:25700349

  13. IL-17-Expressing CD4+ and CD8+ T Lymphocytes in Human Toxoplasmosis

    PubMed Central

    Alves Silva, Jéssica Líver; da Silva, Marcos Vinicius; Gómez-Hernández, César; Crema Peghini, Bethânea; Silva, Neide Maria; Mineo, José Roberto; Rodrigues Júnior, Virmondes

    2014-01-01

    This study aimed to measure the synthesis of Th1 and Th2 cytokines by mononuclear cells after culture with live T. gondii and identified Th17 (CD4+) and Tc17 (CD8+) cells in toxoplasma-seronegative and toxoplasma-seropositive parturient and nonpregnant women. Cytometric bead arrays were used to measure cytokine levels (IL-2, TNF-α, IFN-γ, IL-4, IL-5, and IL-10); immunophenotyping was used to characterize Th17 and Tc17 cells, and the cells were stained with antibodies against CD4+ and CD8+ T cells expressing IL-17. The addition of tachyzoites to cell cultures induced the synthesis of IL-5, IL-10, and TNF-α by cells from seronegative parturient women and of IL-5 and IL-10 by cells from seropositive, nonpregnant women. We observed a lower level of IL-17-expressing CD4+ and CD8+ T lymphocytes in cultures of cells from seronegative and seropositive parturient and nonpregnant women that were stimulated with tachyzoites, whereas analysis of the CD4+ and CD8+ T cell populations showed a higher level of CD4+ T cells compared with CD8+ T cells. These results suggest that the cytokine pattern and IL-17-expressing CD4+ and CD8+ T lymphocytes may have important roles in the inflammatory response to T. gondii, thus contributing to the maintenance of pregnancy and control of parasite invasion and replication. PMID:25214715

  14. Clonal heterogeneity of synovial fluid T lymphocytes from patients with rheumatoid arthritis

    SciTech Connect

    Duby, A.D.; Sinclair, A.K.; Osborne-Lawrence, S.L. ); Zeldes, W.; Kan, Li; Fox, D.A. )

    1989-08-01

    Although substantial evidence suggests that synovial T lymphocytes are critical in the pathogenesis of rheumatoid arthritis (RA), little is known regarding their antigenic specificities, antigen receptor gene rearrangements, and mechanisms of activation. To assess the extend of expansion of specific clones among RA synovial fluid T cells, Southern blot analyses of T-cell receptor (TCR) gene rearrangements were performed on 40 RA synovial fluid T-cell clones, as well as on fresh and polyclonally activated T cells from RA synovial fluid, RA peripheral blood, and normal peripheral blood. Two of the clones had identical TCR rearrangement patterns, but the remainder were unique. The nonclonal RA T-cell samples showed the same pattern of TCR {beta}-chain rearrangement that was observed among normal peripheral blood T cells, indicating no dominant clonal T-cell population in these samples. It was noted that with sufficient exposure of autoradiograms of the Southern blots, discrete TCR gene rearrangements, representing in some cases common D{sub {beta}}J{sub {beta}} (D, diversity; J, joining) rearrangements, were evident in T cells from peripheral blood of normal individuals and patients with RA, as well as T cells from RA synovial fluid. Taken together, the findings indicate that only a minor degree of oligoclonality can be demonstrated among T lymphocytes from RA synovial fluid.

  15. Static Adhesion Assay for the Study of Integrin Activation in T Lymphocytes

    PubMed Central

    Strazza, Marianne; Azoulay-Alfaguter, Inbar; Pedoeem, Ariel; Mor, Adam

    2014-01-01

    T lymphocyte adhesion is required for multiple T cell functions, including migration to sites of inflammation and formation of immunological synapses with antigen presenting cells. T cells accomplish regulated adhesion by controlling the adhesive properties of integrins, a class of cell adhesion molecules consisting of heterodimeric pairs of transmembrane proteins that interact with target molecules on partner cells or extracellular matrix. The most prominent T cell integrin is lymphocyte function associated antigen (LFA)-1, composed of subunits αL and β2, whose target is the intracellular adhesion molecule (ICAM)-1. The ability of a T cell to control adhesion derives from the ability to regulate the affinity states of individual integrins. Inside-out signaling describes the process whereby signals inside a cell cause the external domains of integrins to assume an activated state. Much of our knowledge of these complex phenomena is based on mechanistic studies performed in simplified in vitro model systems. The T lymphocyte adhesion assay described here is an excellent tool that allows T cells to adhere to target molecules, under static conditions, and then utilizes a fluorescent plate reader to quantify adhesiveness. This assay has been useful in defining adhesion-stimulatory or inhibitory substances that act on lymphocytes, as well as characterizing the signaling events involved. Although described here for LFA-1 - ICAM-1 mediated adhesion; this assay can be readily adapted to allow for the study of other adhesive interactions (e.g. VLA-4 - fibronectin). PMID:24961998

  16. Regulatory T-lymphocytes mediate amyotrophic lateral sclerosis progression and survival

    PubMed Central

    Henkel, Jenny S; Beers, David R; Wen, Shixiang; Rivera, Andreana L; Toennis, Karen M; Appel, Joan E; Zhao, Weihua; Moore, Dan H; Powell, Suzanne Z; Appel, Stanley H

    2013-01-01

    In amyotrophic lateral sclerosis (ALS) mice, regulatory T-lymphocytes (Tregs) are neuroprotective, slowing disease progression. To address whether Tregs and FoxP3, a transcription factor required for Treg function, similarly influence progression rates of ALS patients, T-lymphocytes from patients were assessed by flow cytometry. Both numbers of Tregs and their FoxP3 protein expressions were reduced in rapidly progressing ALS patients and inversely correlated with progression rates. The mRNA levels of FoxP3, TGF-β, IL4 and Gata3, a Th2 transcription factor, were reduced in rapidly progressing patients and inversely correlated with progression rates. Both FoxP3 and Gata3 were accurate indicators of progression rates. No differences in IL10, Tbx21, a Th1 transcription factor or IFN-γ expression were found between slow and rapidly progressing patients. A 3.5-year prospective study with a second larger cohort revealed that early reduced FoxP3 levels were indicative of progression rates at collection and predictive of future rapid progression and attenuated survival. Collectively, these data suggest that Tregs and Th2 lymphocytes influence disease progression rates. Importantly, early reduced FoxP3 levels could be used to identify rapidly progressing patients. PMID:23143995

  17. CD8+ T Lymphocyte Expansion, Proliferation and Activation in Dengue Fever

    PubMed Central

    de Matos, Andréia Manso; Carvalho, Karina Inacio; Rosa, Daniela Santoro; Villas-Boas, Lucy Santos; da Silva, Wanessa Cardoso; Rodrigues, Célia Luiza de Lima; Oliveira, Olímpia Massae Nakasone Peel Furtado; Levi, José Eduardo; Araújo, Evaldo Stanislau Affonso; Pannuti, Claudio Sergio; Luna, Expedito José Albuquerque; Kallas, Esper George

    2015-01-01

    Dengue fever induces a robust immune response, including massive T cell activation. The level of T cell activation may, however, be associated with more severe disease. In this study, we explored the level of CD8+ T lymphocyte activation in the first six days after onset of symptoms during a DENV2 outbreak in early 2010 on the coast of São Paulo State, Brazil. Using flow cytometry we detected a progressive increase in the percentage of CD8+ T cells in 74 dengue fever cases. Peripheral blood mononuclear cells from 30 cases were thawed and evaluated using expanded phenotyping. The expansion of the CD8+ T cells was coupled with increased Ki67 expression. Cell activation was observed later in the course of disease, as determined by the expression of the activation markers CD38 and HLA-DR. This increased CD8+ T lymphocyte activation was observed in all memory subsets, but was more pronounced in the effector memory subset, as defined by higher CD38 expression. Our results show that most CD8+ T cell subsets are expanded during DENV2 infection and that the effector memory subset is the predominantly affected sub population. PMID:25675375

  18. Functional defects of peripheral regulatory T lymphocytes in patients with progressive vitiligo.

    PubMed

    Ben Ahmed, M; Zaraa, I; Rekik, R; Elbeldi-Ferchiou, A; Kourda, N; Belhadj Hmida, N; Abdeladhim, M; Karoui, O; Ben Osman, A; Mokni, M; Louzir, H

    2012-01-01

    Auto-reactive cytotoxic T lymphocytes play a key role in the progressive loss or destruction of melanocytes in vitiligo but the mechanism underlying the loss of self-tolerance is unknown. A deregulation of regulatory T-cell biology has recently been suggested. The analysis of the suppressive effects of peripheral T regulatory cells in vitiligo patients revealed a functional defect in seven of 15 cases. This defect was strongly correlated with disease activity. The evaluation of the percentage of peripheral regulatory T lymphocytes did not reveal any intrinsic quantitative defect. Yet, a decrease in the percentage of such cells was noted in patients with progressive forms, suggesting a recruitment of regulatory T cells from the peripheral blood to the site of injury. This was further corroborated by the significant increase of Forkhead box P3 expression in the vitiliginous skin of patients. Our data support the involvement of a functional defect of peripheral regulatory T cells in the pathogenesis of vitiligo and open new possibilities to advance therapeutic approaches. PMID:21985183

  19. Erythropoietin exerts direct immunomodulatory effects on the cytokine production by activated human T-lymphocytes.

    PubMed

    Todosenko, N M; Shmarov, V A; Malashchenko, V V; Meniailo, M E; Melashchenko, O B; Gazatova, N D; Goncharov, A G; Seledtsov, V I

    2016-07-01

    The effect of erythropoietin-β (Epo-β) on the functional profile of activated human T-lymphocytes remains largely unknown, which hinders clinical application of Epo as an immunomodulatory agent. We studied the direct impact of Epo on the activation status of human T lymphocytes following activation by particles loaded with antibodies (Abs) against human CD2, CD3, and CD28. T cell activation was assessed by the surface expression of CD38 activation marker. Epo did not significantly affect activation status of both CD4(+) and CD4(-) T cells, as well as of naive (CD45RA(+)CD197(+)), central memory (CD45RA(-)CD197(+)), effector memory (CD45RA(-)CD197(-)), and terminally-differentiated (CD45RA(+)CD197(-)) T cells. However, Epo markedly augmented production of IL-2, IL-4 and IL10 by activated T cells with concomitant reduction in IFN-γ secretion. Taken together, our data showed that Epo could directly down-regulate pro-inflammatory T cell responses without affecting T cell activation status. PMID:27208431

  20. Cytokine Pattern of T Lymphocytes in Acute Schistosomiasis mansoni Patients following Treated Praziquantel Therapy.

    PubMed

    Silveira-Lemos, Denise; Fernandes Costa-Silva, Matheus; Cardoso de Oliveira Silveira, Amanda; Azevedo Batista, Mauricio; Alves Oliveira-Fraga, Lúcia; Soares Silveira, Alda Maria; Barbosa Alvarez, Maria Carolina; Martins-Filho, Olindo Assis; Gazzinelli, Giovanni; Corrêa-Oliveira, Rodrigo; Teixeira-Carvalho, Andréa

    2013-01-01

    Acute schistosomiasis is associated with a primary exposure and is more commonly seen in nonimmune individuals traveling through endemic regions. In this study, we have focused on the cytokine profile of T lymphocytes evaluated in circulating leukocytes of acute Schistosomiasis mansoni-infected patients (ACT group) before and after praziquantel treatment (ACT-TR group). Our data demonstrated increased values of total leukocytes, eosinophils, and monocytes in both groups. Interestingly, we have observed that patients treated with praziquantel showed increased values of lymphocytes as compared with noninfected group (NI) or ACT groups. Furthermore, a decrease of neutrophils in ACT-TR was observed when compared to ACT group. Analyses of short-term in vitro whole blood stimulation demonstrated that, regardless of the presence of soluble Schistosoma mansoni eggs antigen (SEA), increased synthesis of IFN-γ and IL-4 by T-cells was observed in the ACT group. Analyses of cytokine profile in CD8 T cells demonstrated higher percentage of IFN-γ and IL-4 cells in both ACT and ACT-TR groups apart from increased percentage of IL-10 cells only in the ACT group. This study is the first one to point out the relevance of CD8 T lymphocytes in the immune response induced during the acute phase of schistosomiasis. PMID:23401741

  1. Cytokine Pattern of T Lymphocytes in Acute Schistosomiasis mansoni Patients following Treated Praziquantel Therapy

    PubMed Central

    Silveira-Lemos, Denise; Fernandes Costa-Silva, Matheus; Cardoso de Oliveira Silveira, Amanda; Azevedo Batista, Mauricio; Alves Oliveira-Fraga, Lúcia; Soares Silveira, Alda Maria; Barbosa Alvarez, Maria Carolina; Martins-Filho, Olindo Assis; Gazzinelli, Giovanni; Corrêa-Oliveira, Rodrigo; Teixeira-Carvalho, Andréa

    2013-01-01

    Acute schistosomiasis is associated with a primary exposure and is more commonly seen in nonimmune individuals traveling through endemic regions. In this study, we have focused on the cytokine profile of T lymphocytes evaluated in circulating leukocytes of acute Schistosomiasis mansoni-infected patients (ACT group) before and after praziquantel treatment (ACT-TR group). Our data demonstrated increased values of total leukocytes, eosinophils, and monocytes in both groups. Interestingly, we have observed that patients treated with praziquantel showed increased values of lymphocytes as compared with noninfected group (NI) or ACT groups. Furthermore, a decrease of neutrophils in ACT-TR was observed when compared to ACT group. Analyses of short-term in vitro whole blood stimulation demonstrated that, regardless of the presence of soluble Schistosoma mansoni eggs antigen (SEA), increased synthesis of IFN-γ and IL-4 by T-cells was observed in the ACT group. Analyses of cytokine profile in CD8 T cells demonstrated higher percentage of IFN-γ and IL-4 cells in both ACT and ACT-TR groups apart from increased percentage of IL-10 cells only in the ACT group. This study is the first one to point out the relevance of CD8 T lymphocytes in the immune response induced during the acute phase of schistosomiasis. PMID:23401741

  2. A novel regulatory mechanism of naringenin through inhibition of T lymphocyte function in contact hypersensitivity suppression

    SciTech Connect

    Fang, Feng; Tang, Yijun; Gao, Zhe; Xu, Qiang

    2010-06-25

    Naringenin, a flavonoid in grapefruits and citrus fruits, has been reported to exhibit anti-inflammatory and anti-oxidative activities. Contact hypersensitivity (CHS) is a T cell-mediated immune reaction, and the factors released from macrophages also contribute to this response. Previous studies showed that naringenin suppressed CHS by inhibiting activation and migration of macrophages. However, little is known about naringenin's effects on T lymphocytes. Our study indicated that naringenin potently suppressed picryl chloride (PCl)-induced contact hypersensitivity by inhibiting the proliferation and activation of T lymphocytes. In vitro, both of the activated hapten-specific T cells and the T cells stimulated with anti-CD3/anti-CD28 showed growth arrest after naringenin treatment. Furthermore, naringenin reduced CD69 (the protein level) and cytokines such as IL-2, TNF-{alpha}, and IFN-{gamma} (the mRNA level) expressions which highly expressed by activated T cells. Meanwhile, naringenin also induced T cell apoptosis by upregulation of Bax, Bad, PARP, cleaved-caspase 3 and downregulation of phosphorylated Akt, Bcl-2. These findings suggest that, besides its anti-inflammatory activities in macrophages, naringenin also showed inhibitory effects on the activation and proliferation of T cells to alleviate symptoms of contact hypersensitivity.

  3. Apoptotic CD8 T-lymphocytes disable macrophage-mediated immunity to Trypanosoma cruzi infection

    PubMed Central

    Cabral-Piccin, M P; Guillermo, L V C; Vellozo, N S; Filardy, A A; Pereira-Marques, S T; Rigoni, T S; Pereira-Manfro, W F; DosReis, G A; Lopes, M F

    2016-01-01

    Chagas disease is caused by infection with the protozoan Trypanosoma cruzi. CD8 T-lymphocytes help to control infection, but apoptosis of CD8 T cells disrupts immunity and efferocytosis can enhance parasite infection within macrophages. Here, we investigate how apoptosis of activated CD8 T cells affects M1 and M2 macrophage phenotypes. First, we found that CD8 T-lymphocytes and inflammatory monocytes/macrophages infiltrate peritoneum during acute T. cruzi infection. We show that treatment with anti-Fas ligand (FasL) prevents lymphocyte apoptosis, upregulates type-1 responses to parasite antigens, and reduces infection in macrophages cocultured with activated CD8 T cells. Anti-FasL skews mixed M1/M2 macrophage profiles into polarized M1 phenotype, both in vitro and following injection in infected mice. Moreover, inhibition of T-cell apoptosis induces a broad reprogramming of cytokine responses and improves macrophage-mediated immunity to T. cruzi. The results indicate that disposal of apoptotic CD8 T cells increases M2-macrophage differentiation and contributes to parasite persistence. PMID:27195678

  4. Apoptotic CD8 T-lymphocytes disable macrophage-mediated immunity to Trypanosoma cruzi infection.

    PubMed

    Cabral-Piccin, M P; Guillermo, L V C; Vellozo, N S; Filardy, A A; Pereira-Marques, S T; Rigoni, T S; Pereira-Manfro, W F; DosReis, G A; Lopes, M F

    2016-01-01

    Chagas disease is caused by infection with the protozoan Trypanosoma cruzi. CD8 T-lymphocytes help to control infection, but apoptosis of CD8 T cells disrupts immunity and efferocytosis can enhance parasite infection within macrophages. Here, we investigate how apoptosis of activated CD8 T cells affects M1 and M2 macrophage phenotypes. First, we found that CD8 T-lymphocytes and inflammatory monocytes/macrophages infiltrate peritoneum during acute T. cruzi infection. We show that treatment with anti-Fas ligand (FasL) prevents lymphocyte apoptosis, upregulates type-1 responses to parasite antigens, and reduces infection in macrophages cocultured with activated CD8 T cells. Anti-FasL skews mixed M1/M2 macrophage profiles into polarized M1 phenotype, both in vitro and following injection in infected mice. Moreover, inhibition of T-cell apoptosis induces a broad reprogramming of cytokine responses and improves macrophage-mediated immunity to T. cruzi. The results indicate that disposal of apoptotic CD8 T cells increases M2-macrophage differentiation and contributes to parasite persistence. PMID:27195678

  5. Molecular analyses of in vivo hprt mutations in human T-lymphocytes: IV. Studies in newborns

    SciTech Connect

    McGinniss, M.J.; Nicklas, J.A.; Albertini, R.J. )

    1989-01-01

    In order to characterize in vivo gene mutations that occur during fetal development, molecular analyses were undertaken of mutant 6-thioguanine resistant T-lymphocytes isolated from placental cord blood samples of 13 normal male newborns. These mutant T-cells were studied to define hypoxanthine-guanine phosphoribosyltransferase (hprt) gene structural alterations and to determine T-cell receptor (TCR) gene rearrangement patterns. Structural hprt alterations, as shown by Southern blot analyses, occurred in 85% of these mutant clones. These alterations consisted mostly of deletion of exons 2 and 3. These findings contrast with the 10-20% of gross structural alterations occurring randomly across the entire gene previously reported for T-cell mutants isolated from normal young adults. Iterative analyses of hprt structural alterations and TCR gene rearrangement patterns show that approximately one-third of the newborn derived mutants may have originated as pre- or intrathymic hprt mutations. This too contrasts with previous findings in adults where the background in vivo hprt mutations appeared to originate in postthymic T-lymphocytes.

  6. Dissecting eukaryotic cells by coherent phase microscopy: quantitative analysis of quiescent and activated T lymphocytes

    NASA Astrophysics Data System (ADS)

    Tychinsky, Vladimir P.; Kretushev, Alexander V.; Vyshenskaya, Tatiana V.; Shtil, Alexander A.

    2012-07-01

    We present a concept for quantitative characterization of a functional state of an individual eukaryotic cell based on interference imaging. The informative parameters of the phase images of quiescent and mitogen-activated T lymphocytes included the phase thickness, phase volume, the area, and the size of organelles. These parameters were obtained without a special hypothesis about cell structure. Combinations of these parameters generated a ``phase portrait'' of the cell. A simplified spherical multilayer optic model of a T lymphocyte was used to calculate the refractivity profile, to identify structural elements of the image with the organelles, and to interpret the parameters of the phase portrait. The values of phase image parameters underwent characteristic changes in the course of mitogenic stimulation of T cells; thereby, the functional state of individual cells can be described using these parameters. Because the values of the components of the phase portrait are measured in absolute units, it is possible to compare the parameters of images obtained with different interference microscopes. Thus, the analysis of phase portraits provides a new and perspective approach for quantitative, real-time analysis of subcellular structure and physiologic state of an individual cell.

  7. Physical association and functional interaction between beta1 integrin and CD98 on human T lymphocytes

    NASA Technical Reports Server (NTRS)

    Miyamoto, Yuko J.; Mitchell, Jason S.; McIntyre, Bradley W.

    2003-01-01

    CD98 is a cell surface protein previously characterized as a cell activation marker, an amino acid transporter, and has recently been implicated in integrin-related functions. Integrins are cell surface proteins, important for homotypic cell aggregation, cell adhesion, and coactivation of T lymphocytes. We have previously shown that the anti-CD98 mAb 80A10, when coimmobilized with anti-CD3 mAb OKT3, is able to mediate human T cell coactivation that is inhibited by anti-beta1 integrin specific mAb 18D3. These results indicated a functional association of CD98 and beta1 integrin signaling but left open the question of a physical association. We now show the induction of homotypic aggregation through CD98 among human T cells and this aggregation was inhibited by anti-beta1 integrin mAb. Therefore, CD98-dependent lymphocyte proliferation and adhesion may involve integrins. Competitive binding assays and fluorescence colocalization analysis suggested that CD98 and beta1 integrin were physically associated. Differential extraction techniques and immunoprecipitations provided the first evidence that the alpha4beta1 integrin and CD98 are specifically associated on human T lymphocytes.

  8. Dietary n-3 polyunsaturated fatty acids increase T-lymphocyte phospholipid mass and acyl-CoA binding protein expression.

    PubMed

    Collison, Lauren W; Collison, Robert E; Murphy, Eric J; Jolly, Christopher A

    2005-01-01

    Dietary flaxseed oil, which is enriched in alpha-linolenic acid, and fish oil, which is enriched in EPA and DHA, possess anti-inflammatory properties when compared with safflower oil, which is enriched in linoleic acid. The influence of flaxseed oil and fish oil feeding on lipid metabolism in T-lymphocytes is currently unknown. This study directly compared the effects of feeding safflower oil, flaxseed oil, and fish oil for 8 wk on splenic T-lymphocyte proliferation, phospholipid mass, and acyl-CoA binding protein expression in the rat. The data show that both flaxseed oil and fish oil increased acyl-CoA binding protein expression and phosphatidic acid mass in unstimulated T-lymphocytes when compared with safflower oil feeding. Fish oil feeding increased cardiolipin mass, whereas flaxseed oil had no effect. After stimulation, flaxseed oil and fish oil blunted T-lymphocyte interleukin-2 production and subsequent proliferation, which was associated with the lack of increased acyl-CoA binding protein expression. The results reported show evidence for a novel mechanism by which dietary flaxseed oil and fish oil suppress T-lymphocyte proliferation via changes in acyl-CoA binding protein expression and phospholipid mass. PMID:15825833

  9. Frequency and phenotype of JC virus-specific CD8+ T lymphocytes in the peripheral blood of patients with progressive multifocal leukoencephalopathy.

    PubMed

    Lima, Marco A; Marzocchetti, Angela; Autissier, Patrick; Tompkins, Troy; Chen, Yiping; Gordon, Jennifer; Clifford, David B; Gandhi, Rajesh T; Venna, Nagagopal; Berger, Joseph R; Koralnik, Igor J

    2007-04-01

    JC virus (JCV)-specific CD8+ cytotoxic T lymphocytes (CTL) are associated with a favorable outcome in patients with progressive multifocal leukoencephalopathy (PML) and cross-recognize the polyomavirus BK virus (BKV). We sought to determine the frequency and phenotype in fresh blood of CD8+ T cells specific for two A*0201-restricted JCV epitopes, VP1(p36) and VP1(p100), and assess their impact on JC and BK viremia and viruria in 15 healthy subjects, eight human immunodeficiency virus-positive (HIV+) individuals, and nine HIV+ patients with PML (HIV+ PML patients) classified as survivors. After magnetic pre-enrichment of CD8+ T cells, epitope-specific cells ranged from 0.001% to 0.022% [corrected] by tetramer staining, with no significant difference among the three study groups. By use of seven-color flow cytometry, there was no predominant differentiation phenotype subset among JCV-specific CD8+ T cells in healthy individuals, HIV+ subjects, or HIV+ PML patients. However, in one HIV+ PML patient studied in the acute phase, there was a majority of activated effector memory cells. BKV DNA was undetectable in all blood samples by quantitative PCR, while a low JC viral load was found in the blood of only one HIV+ and two HIV+ PML patients. JCV and BKV DNA were detected in 33.3% and 13.3% of all urine samples, respectively, independent of the presence of JCV-specific CTL. The detection of JCV DNA in the urine was associated with the presence of a JCV VP1(p100) CTL response. Immunotherapies aiming at increasing the cellular immune response against JCV may be valuable in the treatment of HIV+ individuals with PML. PMID:17229701

  10. In vivo induction of a high-avidity, high-frequency cytotoxic T-lymphocyte response is associated with antiviral protective immunity.

    PubMed

    Sedlik, C; Dadaglio, G; Saron, M F; Deriaud, E; Rojas, M; Casal, S I; Leclerc, C

    2000-07-01

    Many approaches are currently being developed to deliver exogenous antigen into the major histocompatibility complex class I-restricted antigen pathway, leading to in vivo priming of CD8(+) cytotoxic T cells. One attractive possibility consists of targeting the antigen to phagocytic or macropinocytic antigen-presenting cells. In this study, we demonstrate that strong CD8(+) class I-restricted cytotoxic responses are induced upon intraperitoneal immunization of mice with different peptides, characterized as CD8(+) T-cell epitopes, bound to 1-microm synthetic latex microspheres and injected in the absence of adjuvant. The cytotoxic response induced against a lymphocytic choriomeningitis virus (LCMV) peptide linked to these microspheres was compared to the cytotoxic T-lymphocyte (CTL) response obtained upon immunization with the nonreplicative porcine parvovirus-like particles (PPV:VLP) carrying the same peptide (PPV:VLP-LCMV) previously described (C. Sedlik, M. F. Saron, J. Sarraseca, I. Casal, and C. Leclerc, Proc. Natl. Acad. Sci. USA 94:7503-7508, 1997). We show that the induction of specific CTL activity by peptides bound to microspheres requires CD4(+) T-cell help in contrast to the CTL response obtained with the peptide delivered by viral pseudoparticles. Furthermore, PPV:VLP are 100-fold more efficient than microspheres in generating a strong CTL response characterized by a high frequency of specific T cells of high avidity. Moreover, PPV:VLP-LCMV are able to protect mice against a lethal LCMV challenge whereas microspheres carrying the LCMV epitope fail to confer such protection. This study demonstrates the crucial involvement of the frequency and avidity of CTLs in conferring antiviral protective immunity and highlights the importance of considering these parameters when developing new vaccine strategies. PMID:10846055

  11. Kinesin superfamily protein-derived peptides with the ability to induce glioma-reactive cytotoxic T lymphocytes in human leukocyte antigen-A24+ glioma patients.

    PubMed

    Harada, Mamoru; Ishihara, Yuki; Itoh, Kyogo; Yamanaka, Ryuya

    2007-03-01

    One promising modality in the treatment of malignant glioma is specific immunotherapy. However, this modality requires information about target antigens and their epitope peptides that are recognized by T cells. In this study, we searched for new target candidates in specific immunotherapy for malignant glioma by utilizing cDNA microarray technology to compare gene expressions in malignant glioma tissues to those in benign glioma and a panel of normal tissues. The selected genes included three members of the kinesin superfamily proteins (KIFs): KIF1C, KIF3C, and KIF21B. RT-PCR showed that these three genes were expressed in the majority of glioma cell lines. These antigen-derived 25 peptides, which had the ability to bind to human leukocyte antigen (HLA)-A24 molecules, were first screened for their ability to be recognized by the immunoglobulin G of glioma patients, and then tested for their potential to induce peptide-specific and glioma-reactive cytotoxic T lymphocytes (CTLs) from the peripheral blood mononuclear cells of HLA-A24+ glioma patients. The results showed that the KIF1C149-158 and KIF3C512-520 peptides efficiently induced HLA-A24-restricted and glioma-reactive CD8+ T cells. These results suggest the existence of KIF-reactive CTL precursors in glioma patients, and should facilitate the development of specific immunotherapies for malignant glioma. PMID:17273744

  12. Autophagy Restricts HIV-1 Infection by Selectively Degrading Tat in CD4+ T Lymphocytes

    PubMed Central

    Sagnier, Sophie; Daussy, Coralie F.; Borel, Sophie; Robert-Hebmann, Véronique; Faure, Mathias; Blanchet, Fabien P.; Beaumelle, Bruno; Biard-Piechaczyk, Martine

    2014-01-01

    ABSTRACT Autophagy is a ubiquitous mechanism involved in the lysosomal-mediated degradation of cellular components when they are engulfed in vacuoles called autophagosomes. Autophagy is also recognized as an important regulator of the innate and adaptive immune responses against numerous pathogens, which have, therefore, developed strategies to block or use the autophagy machinery to their own benefit. Upon human immunodeficiency virus type 1 (HIV-1) infection, viral envelope (Env) glycoproteins induce autophagy-dependent apoptosis of uninfected bystander CD4+ T lymphocytes, a mechanism likely contributing to the loss of CD4+ T cells. In contrast, in productively infected CD4+ T cells, HIV-1 is able to block Env-induced autophagy in order to avoid its antiviral effect. To date, nothing is known about how autophagy restricts HIV-1 infection in CD4+ T lymphocytes. Here, we report that autophagy selectively degrades the HIV-1 transactivator Tat, a protein essential for viral transcription and virion production. We demonstrated that this selective autophagy-mediated degradation of Tat relies on its ubiquitin-independent interaction with the p62/SQSTM1 adaptor. Taken together, our results provide evidence that the anti-HIV effect of autophagy is specifically due to the degradation of the viral transactivator Tat but that this process is rapidly counteracted by the virus to favor its replication and spread. IMPORTANCE Autophagy is recognized as one of the most ancient and conserved mechanisms of cellular defense against invading pathogens. Cross talk between HIV-1 and autophagy has been demonstrated depending on the virally challenged cell type, and HIV-1 has evolved strategies to block this process to replicate efficiently. However, the mechanisms by which autophagy restricts HIV-1 infection remain to be elucidated. Here, we report that the HIV-1 transactivator Tat, a protein essential for viral replication, is specifically degraded by autophagy in CD4+ T lymphocytes

  13. Effect of major burns on early and late activating markers of peripheral blood T lymphocytes.

    PubMed

    Sayed, S; Bakry, R; El-Shazly, M; El-Oteify, M; Terzaki, S; Fekry, M

    2012-03-31

    It is known that lymphocytes immunophenotype is a reflection of the functional level of the immune system. The immunosuppressive effect of major burns is also known for many years. T lymphocytes of 50 major burn patients were analyzed in base line (BL) samples at 24 hours and at 1 week and 2 weeks after burn, using monoclonal antibodies of CD3, CD4, CD8, CD25 (IL2R) and HLA-DR by flow cytometry and β2-microglobulin (β2-m) by ELISA. Recorded values were compared with those of 50 healthy donors. There was statistically significant reduction in absolute number of CD3 positive cells (CD3+) (p<0.000) and CD4/CD8 ratio (p=0.01) in the first 24 hours in comparison with controls. CD25 (IL-2R) shows insignificant upregulation on T lymphocytes after burn with significant upregulation of HLA-DR. The absolute number of CD3+ cells began to increase after 2 weeks (p=0.03) but remained less than controls (p=0.08). CD4/CD8 ratio was more or less same as healthy controls after 2 weeks. Upregulation of CD25 was insignificantly increased and that of HLA-DR was markedly increased after 2 weeks (p=0.001). Significant negative correlations were detected between mean values of β2-m and both absolute numbers of CD3 and CD4 positive cells in BL and one week samples. In addition there was significant correlation between mean values of β2-m and values of CD25 expression in the BL samples. The obtained data is suggestive of persistent activation of T lymphocytes two weeks after major burns whereas early shedding of β2-m is related to activation of lymphocytes increasing their susceptibility to apoptosis, both indicative of altered immune response. Burn intensivists and surgeons should be keen to support the patients' immune system in the first hours following major burns. This support will ensure free-bacteremic blood with a consequent better prognosis. PMID:23012611

  14. Detection of CD4+ and CD8 + T-lymphocytes with the optofluidic ring resonator (OFRR) biosensor

    NASA Astrophysics Data System (ADS)

    Gohring, John T.; Fan, Xudong

    2009-05-01

    We have demonstrated the use of the Opto-Fluidic ring resonator (OFRR) to achieve the label-free detection of CD4+ and CD8+ T-Lymphocytes. The OFRR sensing technology combines microfluidics and optical sensing in a small platform that achieves rapid detection. In this work, white blood cells were obtained from healthy blood and the concentration altered to reflect CD4 and CD8 concentrations of HIV infected individuals. The OFRR was modified to effectively capture these receptors located on T-Lymphocytes and obtain a sensing signal through interaction with an evanescent field. Results show isolation of CD4+ and CD8+ T-Lymphocytes at medically significant levels. This work will lead to a device that can provide a CD4 and CD8 count to measure HIV progression in a low cost sensing setup.

  15. Evidence for the presence of a low molecular-weight activator of suppressor monocytes (LASM) in dialysates of T lymphocytes.

    PubMed

    Nekam, K; Strelkauskas, A J; Fudenberg, H H; Donnan, G G; Goust, J M

    1981-05-01

    Lysates of peripheral blood T lymphocytes from healthy individuals were found to contain a low molecular-weight peptide that inhibited phytohaemagglutinin-induced DNA synthesis in vitro by autologous or allogeneic peripheral blood mononuclear cells. The peptide was dialysable, partially heat stable, resistant to trypsin, RNase, and DNase but not to pronase, and was not part of the membrane receptor involved in rosette formation by T lymphocytes with sheep erythrocytes. It was found to act through monocytes, inducing the synthesis of second mediator responsible for the inhibition of lymphocyte DNA synthesis. This inducer of inhibition, designated as "low molecular-weight activator of suppressor monocytes' (LASM), may have a role in the depression of cellular immune response seen in various pathological conditions involving the destruction of T lymphocytes. PMID:6972906

  16. Evidence for the presence of a low molecular-weight activator of suppressor monocytes (LASM) in dialysates of T lymphocytes.

    PubMed Central

    Nekam, K; Strelkauskas, A J; Fudenberg, H H; Donnan, G G; Goust, J M

    1981-01-01

    Lysates of peripheral blood T lymphocytes from healthy individuals were found to contain a low molecular-weight peptide that inhibited phytohaemagglutinin-induced DNA synthesis in vitro by autologous or allogeneic peripheral blood mononuclear cells. The peptide was dialysable, partially heat stable, resistant to trypsin, RNase, and DNase but not to pronase, and was not part of the membrane receptor involved in rosette formation by T lymphocytes with sheep erythrocytes. It was found to act through monocytes, inducing the synthesis of second mediator responsible for the inhibition of lymphocyte DNA synthesis. This inducer of inhibition, designated as "low molecular-weight activator of suppressor monocytes' (LASM), may have a role in the depression of cellular immune response seen in various pathological conditions involving the destruction of T lymphocytes. PMID:6972906

  17. Phenotypic Identification of Spinal Cord-Infiltrating CD4+ T Lymphocytes in a Murine Model of Neuropathic Pain

    PubMed Central

    Draleau, KS; Maddula, S; Slaiby, A; Nutile-McMenemy, N; De Leo, JA; Cao, L

    2014-01-01

    Background Neuropathic pain is one of the most devastating kinds of chronic pain. Neuroinflammation has been shown to contribute to the development of neuropathic pain. We have previously demonstrated that lumbar spinal cord-infiltrating CD4+ T lymphocytes contribute to the maintenance of mechanical hypersensitivity in spinal nerve L5 transection (L5Tx), a murine model of neuropathic pain. Here, we further examined the phenotype of the CD4+ T lymphocytes involved in the maintenance of neuropathic pain-like behavior via intracellular flow cytometric analysis and explored potential interactions between infiltrating CD4+ T lymphocytes and spinal cord glial cells. Results We consistently observed significantly higher numbers of T-Bet+, IFN-γ+, TNF-α+, and GM-CSF+, but not GATA3+ or IL-4+, lumbar spinal cord-infiltrating CD4+ T lymphocytes in the L5Tx group compared to the sham group at day 7 post-L5Tx. This suggests that the infiltrating CD4+ T lymphocytes expressed a pro-inflammatory type 1 phenotype (Th1). Despite the observation of CD4+ CD40 ligand (CD154)+ T lymphocytes in the lumbar spinal cord post-L5Tx, CD154 knockout (KO) mice did not display significant changes in L5Tx-induced mechanical hypersensitivity, indicating that T lymphocyte-microglial interaction through the CD154-CD40 pathway is not necessary for L5Tx-induced hypersensitivity. In addition, spinal cord astrocytic activation, represented by glial fibillary acidic protein (GFAP) expression, was significantly lower in CD4 KO mice compared to wild type (WT) mice at day 14 post-L5Tx, suggesting the involvement of astrocytes in the pronociceptive effects mediated by infiltrating CD4+ T lymphocytes. Conclusions In all, these data indicate that the maintenance of L5Tx-induced neuropathic pain is mostly mediated by Th1 cells in a CD154-independent manner via a mechanism that could involve multiple Th1 cytokines and astrocytic activation. PMID:25143871

  18. [Structure and function of the T-lymphocyte antigen receptor and its role in infectious diseases].

    PubMed

    Peralta Zaragoza, O; Sánchez Magaña, T; Barrera Rodriguez, R; Madrid Marina, V

    1996-01-01

    The T lymphocytes recognize antigens through antigen receptors (TcRs) and the major histocompatibility complex (MHC) molecules: they lysate the cells that bear the antigen, or release cytokines that are mediators of the immune response. The TcRs recognize antigens in the form of short peptides bound to MHC molecules. So far, there are two isotypes of TcR: gamma/delta and alpha/beta, which appear in the sequence during T-cell ontogeny. The process of selection of TcRs during thymic ontogeny obeys to molecular mechanisms which generate intracellular events that will participate in the gene expression of the TcR. The aim of the present paper is to review the molecular, structural, and functional aspects of the TcRs, and their role in human autoimmune infectious disease. PMID:8815490

  19. Emerging technologies for point-of-care CD4 T-lymphocyte counting

    PubMed Central

    Boyle, David S.; Hawkins, Kenneth R.; Steele, Matthew S.; Singhal, Mitra; Cheng, Xuanhong

    2012-01-01

    A CD4 T-lymphocyte count determines eligibility for antiretroviral therapy (ART) with patients recently diagnosed with HIV and also monitors the efficacy of ART treatment thereafter. ART slows the progression of HIV to AIDS. In the developing world, CD4 tests are often performed in centralized laboratories, typically in urban areas. The expansion of ART programs into rural areas has created a need for rapid CD4 counting as logistical barriers can delay the timely dissemination of test results and affect patient care through delay in intervention or loss of follow-up care. CD4 measurement at the point-of-care (POC) in rural areas could help facilitating ART and monitoring of treatment. This review highlights recent technology developments with applications towards determining CD4 counts at the POC. PMID:21798607

  20. Telomerase-based pharmacologic enhancement of antiviral function of human CD8+ T lymphocytes.

    PubMed

    Fauce, Steven Russell; Jamieson, Beth D; Chin, Allison C; Mitsuyasu, Ronald T; Parish, Stan T; Ng, Hwee L; Kitchen, Christina M Ramirez; Yang, Otto O; Harley, Calvin B; Effros, Rita B

    2008-11-15

    Telomerase reverse transcribes telomere DNA onto the ends of linear chromosomes and retards cellular aging. In contrast to most normal somatic cells, which show little or no telomerase activity, immune cells up-regulate telomerase in concert with activation. Nevertheless, during aging and chronic HIV-1 infection, there are high proportions of dysfunctional CD8(+) CTL with short telomeres, suggesting that telomerase is limiting. The present study shows that exposure of CD8(+) T lymphocytes from HIV-infected human donors to a small molecule telomerase activator (TAT2) modestly retards telomere shortening, increases proliferative potential, and, importantly, enhances cytokine/chemokine production and antiviral activity. The enhanced antiviral effects were abrogated in the presence of a potent and specific telomerase inhibitor, suggesting that TAT2 acts primarily through telomerase activation. Our study is the first to use a pharmacological telomerase-based approach to enhance immune function, thus directly addressing the telomere loss immunopathologic facet of chronic viral infection. PMID:18981163

  1. Anticytotoxic T-Lymphocyte Antigen-4 Induced Autoimmune Hypophysitis: A Case Report and Literature Review

    PubMed Central

    Korytkowski, Mary T.

    2015-01-01

    Objective. We describe a case of autoimmune hypophysitis induced by the anticytotoxic T-lymphocyte antigen-4 (CTLA-4) agent, ipilimumab. Methods. Case presentation and review of the literature. Results. Autoimmune hypophysitis, a previously described rare disorder, is being recognized more frequently as a side effect of novel immunomodulatory agents used in the treatment of malignancies such as melanoma. CTLA-4 agents are associated with immune-related adverse effects (irAE) which occur as a result of activation (or lack of inactivation) of the immune response. This impacts not only malignant cells but also different host organ-systems. Autoimmune hypophysitis is one of several endocrinopathies associated with these agents. Conclusion. It is important that endocrinologists become familiar with the endocrinopathies, such as autoimmune hypophysitis, associated with new immunomodulator agents which are being used with increasing frequency to treat a variety of malignancies. PMID:25694832

  2. [Lichen planus, a T-lymphocyte mediated reaction involving the skin and mucous membranes].

    PubMed

    van den Akker, T W

    2001-10-01

    Lichen planus concerns a benign skin disorder without involvement of other organ systems. Its course is generally limited to less than a year. Classic lichen planus is characterized by pruritic, violaceous, plane papules which occur most commonly on the inside of the wrists, the lower back, the lower legs and the perimalleolar region of adults aged between 30-60 years. Frequently, oral and genital mucous membrane lesions are involved. Erosive mucosal lesions are particularly painful and long-lasting. Many clinical variants have been described ranging from lichenoid drug eruptions to associations with graft-versus-host disease. The cause of lichen planus is unknown. An immunopathological pathogenesis with T-lymphocytes directed against basal keratinocytes or the basal membrane zone is assumed. Multiple therapeutic options exist: local and systemic corticosteroids, psoralens with ultraviolet A light (PUVA), retinoids, cyclosporin. PMID:11675973

  3. Ethanol-induced CD3 and CD2 hyporesponsiveness of peripheral blood T lymphocytes.

    PubMed

    Spinozzi, F; Agea, E; Fiorucci, G; Gerli, R; Muscat, C; Belia, S; Bertotto, A

    1992-01-01

    The functional relevance of a direct ethanol effect on the membrane structure of T lymphocytes and accessory cells (APC), as well as on signal transduction systems was studied in ten normal subjects. Ethanol incubation (80 mM for 24h) of highly purified T cells increased the number of CD4+/CD45RA+ lymphocytes. In contrast, ethanol exposure induced a drop in CD14+/LFA-3+ APC values. These changes were accompanied by faulty T-cell proliferation in response to anti-CD3 and anti-CD2 mAb and inhibition of CD3- and CD2-mediated rises in intracellular calcium and, to a lesser extent, inositol 1,4,5-triphosphate levels. These data clearly indicate that a membrane-specific ethanol interaction both modifies surface glycoproteic and/or glycolipidic structures and alters transmembrane transduction of the activation signals. PMID:1363475

  4. Different expression patterns of TRP genes in murine B and T lymphocytes

    SciTech Connect

    Inada, Hitoshi; Iida, Tohko; Tominaga, Makoto . E-mail: tominaga@nips.ac.jp

    2006-11-24

    A prolonged increase in the intracellular calcium concentration ([Ca{sup 2+}]{sub i}) is essential for lymphocyte activation that includes cell proliferation and differentiation. This increase in [Ca{sup 2+}]{sub i} results from Ca{sup 2+} release from the intracellular store and the subsequent Ca{sup 2+} influx from the extracellular environment via calcium channels located on the plasma membrane. Although transient receptor potential (TRP) channels have been reported to play important roles in the [Ca{sup 2+}]{sub i} increase in lymphocytes, the function of these channels in lymphocyte activation remains unknown. Here, we report the comprehensive expression profile of TRP channel gene families including TRPC, TRPV, and TRPM in the murine immune system. RT-PCR analysis revealed different expression patterns of the TRP channel genes in B and T lymphocytes isolated from the spleen. Therefore, our results provide an appropriate reference of TRP gene expression in murine lymphocytes.

  5. The interaction between bovine herpesvirus type 1 and activated bovine T lymphocytes.

    PubMed

    Griebel, P J; Ohmann, H B; Lawman, M J; Babiuk, L A

    1990-02-01

    The interaction between activated bovine T lymphocytes (BTLs) and bovine herpesvirus type 1 (BHV-1) was investigated. BHV-1 infection of BTLs reduced the amplitude of recombinant bovine interleukin 2-induced proliferative responses. This decreased proliferation was caused by a virus-induced lymphocytolysis which was dependent on viable virus and was not inhibited by recombinant bovine interferon-alpha I1. Furthermore, lymphocytolysis was not associated with virus replication or with the synthesis of detectable levels of viral proteins. Electron microscopic examination of virus-infected cells revealed that lymphocytolysis was characterized by early nuclear disintegration resembling apoptosis. These observations suggest that activated T cells, localized at the site of BHV-1 infection, may be susceptible to virus-induced cytolysis. PMID:2155290

  6. Technical modifications in hyperfractionated total body irradiation for T-lymphocyte deplete bone marrow transplant

    SciTech Connect

    Lawton, C.A.; Barber-Derus, S.; Murray, K.J.; Casper, J.T.; Ash, R.C.; Gillin, M.T.; Wilson, J.F. )

    1989-08-01

    The Medical College of Wisconsin implemented a major bone marrow transplant (BMT) program in July 1985. The type of transplants to be focused on were allogeneic T-lymphocyte deplete. Total body irradiation (TBI) was initially patterned after the Memorial method. Patients received total body irradiation in a sitting position at a dose rate of 20-25 cGy/minute with 50% attenuation lung blocks used both anterior/posterior and posterior/anterior. Electron boosting was utilized for the ribs beneath the lung blocks. Occasionally, lower extremity boosting was required because of the sitting position. A dose of 14 Gy was chosen since T-lymphocyte deplete bone marrow transplant data suggest the need for higher total doses to consistently obtain engraftment. This dose was given in 3 equal daily fractions over 3 days following conditioning chemotherapy. Six of 11 patients treated in this manner developed lethal pulmonary events. In response to the pulmonary toxicity, partial lung shielding was increased to 60% attenuation. In the next 107 patients receiving this program of total body irradiation there was a reduced incidence of fatal pulmonary events (10 cases of fatal idiopathic interstitial pneumonitis and 12 cases of fatal pulmonary infections) after a median follow-up of 9 months. This was an obvious improvement over the initial group. A significant level of hepato-renal toxicity was also observed with 14 Gy total body irradiation when no liver or kidney blocking was used. Of the first 20 patients treated, three cases of fatal veno-occlusive disease resulted. Subsequently, a 10% attenuation right sided liver block was added. Five of 98 patients treated with this block have developed fatal hepatic dysfunction, (median follow-up of 7.2 months).

  7. An ATP-activated channel is involved in mitogenic stimulation of human T lymphocytes.

    PubMed

    Baricordi, O R; Ferrari, D; Melchiorri, L; Chiozzi, P; Hanau, S; Chiari, E; Rubini, M; Di Virgilio, F

    1996-01-15

    We investigated the effect of pharmacologic modulation of the ATP receptor on intracellular ion changes and proliferative response of human peripheral blood lymphocytes (PBLs) and purified T lymphocytes. Extracellular ATP (ATPe) triggered in these cells an increase in the cytoplasmic Ca2+ concentration ([Ca2+]i) and plasma membrane depolarization. Whereas both Ca2+ release from intracellular stores and influx across the plasma membrane were detected in the whole PBL population, only Ca2+ influx was observed in T cells. In the presence of near physiologic extracellular Na+ concentrations (125 mmol/L), Ca2+ permeability through the ATPe-gated channel was very low, suggesting a higher selectivity for monovalent over divalent cations. The selective P2Z agonist benzoylbenzoic ATP (BzATP) increased [Ca2+]i in the presence but not the absence of extracellular Ca2+ and also caused plasma membrane depolarization. The covalent blocker oxidized ATP (oATP), an inhibitor of P2X and P2Z receptors, prevented Ca2+ influx and plasma membrane depolarization, but had no effect on Ca2+ release from stores. Stimulation with ATPe alone had no significant effects on PBL 3H-thymidine incorporation. On the contrary, ATPe or BzATP had a synergistic effect on DNA synthesis stimulated by selective T-cell mitogens such as phytohemagglutinin, anti-CD3 monoclonal antibody, or allogenic PBLs (mixed lymphocyte cultures). Treatment with oATP inhibited mitogenic stimulation by these receptor-directed agents but not by the combined application of the Ca2+ ionophore ionomycin and phorbol myristate acetate. Interleukin-2 partially relieved inhibition by oATP. These results suggest that human T lymphocytes express a plasma membrane channel gated by ATPe that is involved in mitogenic stimulation. PMID:8555491

  8. Autoantibodies against β1-adrenoceptor induce blood glucose enhancement and insulin insufficient via T lymphocytes.

    PubMed

    Gong, Yulin; Xiong, Haiyan; Du, Yunhui; Wu, Ye; Zhang, Suli; Li, Xiao; Liu, Huirong

    2016-04-01

    Diabetes mellitus is a chronic metabolic disorder with a high morbidity and mortality, but its pathogenesis is not fully understood. An increasing amount of evidence indicates that an immune mechanism plays an important role in the pathogenesis of diabetes. We demonstrated previously that the long-term presence of autoantibodies against the second extracellular loop of the β1-adrenoceptor (β1-AA) could change the ratio of peripheral CD4+T/CD8+T in rats, which was accompanied by lymphocytes infiltration in the rat heart, liver, and kidneys. To investigate whether β1-AA is involved in the pathogenesis of diabetes, BALB/c or nude mice were passively immunized with monoclonal antibodies against β1-AR (β1-AR mAb). Compared with vehicle control mice, β1-AA-positive BALB/c mice exhibited significantly increased blood glucose (P < 0.01) and increased fasting insulin (P < 0.05). However, the same changes did not occur in the nude mice. And altered islet morphology was found at week 28 in β1-AA immunization group compared with vehicle control. The basal insulin level of NIT-1 β-cells was decreased markedly (P < 0.01), and the lactate dehydrogenase level was increased (P < 0.01) after the administration of conditioned media from T lymphocytes that had been treated with β1-AA alone. However, these effects were reversed by treatment with metoprolol or peptides of the second extracellular loop of β1-adrenoceptor (β1-AR-ECII). These results suggest that β1-AA could induce hyperglycemia in both rats and mice, and also impair insulin secretion and change islet structure. T lymphocytes may play a key role in the pathogenesis of these changes in the islets. PMID:26639354

  9. Subpopulations of T lymphocytes in psoriasis patients and their changes during immunotherapy.

    PubMed

    Rubins, A Y; Merson, A G

    1987-12-01

    The content of T-lymphocytes and their basic subpopulations T-helpers and T-suppressors have been studied by means of monoclonal antibodies in the peripheral blood of 104 patients with different forms of psoriasis (56 patients with psoriasis vulgaris, 25 with exudative psoriasis, 10 with psoriasis arthropathica, and 13 with erythrodermic psoriasis). In all forms of psoriasis with a slight alteration in T-lymphocyte content a significant dysbalance of T-helpers and T-suppressors was found that brought about a decrease in the correlation ratio T-helpers/T-suppressors (T-helpers/T-suppressors in patients suffering from psoriasis vulgaris, 1.55 +/- 0.12; in those with exudative psoriasis, 1.24 +/- 0.16; with psoriasis arthropathica, 1.33 +/- 0.16; with erythrodermic psoriasis, 1.33 +/- 0.18; the control showed 1.82 +/- 0.08). The decrease in T-helpers/T-suppressors to 1.2 and lower that corresponded to a more severe clinical course of the disease was revealed in 27 patients having psoriasis vulgaris, in 13 with exudative psoriasis, in 7 with psoriasis arthropathica, and in 9 with erythrodermic psoriasis. The dysbalance in T-helpers/T-suppressors was due to a decrease in T-helpers and an increase in T-suppressors. To normalize T-helpers/T-suppressors, 27 psoriatics (20 with psoriasis vulgaris, 6 with exudative psoriasis, 1 with erythrodermic psoriasis) received immunomodulators Thymalinum and Natrii nucleinas in addition to antipsoriatic therapy, which resulted in an increase in T-helper/T-suppressor ratio, on the average up to 1.74 +/- 0.16 (prior to treatment T-helper/T-suppressor ratio in these patients was 1.0 +/- 0.14) and was followed by a favorable clinical course (shorter periods of skin rash regression, prolonged remissions).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2963042

  10. 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.