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Lymphocyte Responses (lymphocyte + response)

Distribution by Scientific Domains
Medical Sciences76%
Life Sciences17%

Kinds of Lymphocyte Responses

  • cytotoxic t lymphocyte response
    		•

    Selected Abstracts

    Lymphocyte Response in Subjects with Chronic Pulmonary Disease Colonized by Pneumocystis jirovecii

    THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2003
    JOSE M VARELA
    No abstract is available for this article. [source]

    Dendritic cells pulsed with ,-fetoprotein and mutant P53 fused gene induce bi-targeted cytotoxic T lymphocyte response against hepatic carcinoma

    CANCER SCIENCE, Issue 7 2008
    Jun Ren
    Dendritic cell (DC)-based immunotherapy is rapidly emerging as a promising treatment in cancer therapy. We had previously shown that DC pulsed with either defined mRNA of tumor antigen (Ag) such as ,-fetoprotein (AFP), or total RNA of hepatocellular carcinoma (HCC) could elicit Ag-specific cytotoxic T lymphocyte (CTL) response. Therefore, we suggested a novel DC-based therapeutic method, in which DCs derived from CD34+ cells enriched peripheral blood mononuclear cells were pulsed with liposome-coated AFP and mutant P53 (mtP53) fused gene pEGFP-C3/AFP-mtP53 to induce bi-targeted specific CTL responses against HCC. Three different genotype HCC cell lines, HepG2 (human histocompatibility leukocyte antigens (HLA) A2 positive, AFP expressing positive, P53 expressing negative), SMMC7721 (HLA A2 positive, neither AFP nor P53 expressing positive), and HMCC97 (HLA A2 positive, both AFP and P53 expressing positive) were selected as targets for CTL responses. An important finding was that DCs pulsed with the liposome-coated fused gene could evoke more intensive bi-targeted Ag-specific CTL responses against HMCC97 than DCs pulsed with either AFP or P53 single gene (P < 0.05). This experimental therapeutic model provides a new promising cytotherapeutic approach, in that DCs pulsed with the fused gene of different Ags might induce more extensive multitargeted antitumor immunity. (Cancer Sci 2008; 99: 1420,1426) [source]

    Programmed death-1 ligands-transfected dendritic cells loaded with glutamic acid decarboxylase 65 (GAD65) inhibit both the alloresponse and the GAD65-reactive lymphocyte response

    CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 1 2008
    F.-R. He
    Summary Type 1 diabetes (T1D) is due to a loss of immune tolerance to islet antigens, such as glutamic acid decarboxylase 65 (GAD65), for which islet transplantation is a promising therapy. Therefore, the generation of tolerance aiming at both alloantigen and GAD65 will help therapeutic intervention greatly in T1D. In this study, we tested the effect of programmed death-1 ligands (PD-L1)-transfected dendritic cells (DC) loaded with GAD65 on the alloresponse and GAD65-reactive lymphocyte response. The DC2·4 cell line was transfected with PD-L1 and co-cultured with GAD65. BALB-c mice were primed, respectively, by intraperitoneal injection with GAD65, PD-L1-transfected- or non-transfected DC (PD-L1/DC or DC), and PD-L1-transfected- or non-transfected DC loaded with GAD65 (PD-L1/DC/GAD65 or DC/GAD65). Splenocytes of treated mice were isolated and restimulated in vitro with GAD65 or the various DC populations above being used as stimulators, respectively. In the mixed lymphocyte reaction, DC/GAD65 were able to stimulate both allogeneic and GAD65-reactive lymphocytes. However, PD-L1/DC/GAD65 were poorer than DC/GAD65 at activating the GAD65-reactive lymphocyte response. Further, although PD-L1/DC could inhibit the alloresponse, PD-L1/DC/GAD65 were more effective at down-regulating the GAD65-reactive lymphocyte response. More importantly, PD-L1/DC/GAD65-primed lymphocytes exhibited the weakest proliferation when again restimulated in vitro by PD-L1/DC/GAD65. Additionally, PD-L1/DC/GAD65 down-regulated interferon-, and up-regulated interleukin-10 production by activated lymphocytes. Therefore, combined stimulation in vivo and in vitro by PD-L1/DC/GAD65 could inhibit both the alloresponse and the GAD65-reactive lymphocyte response, which may contribute to controlling diabetes and islet transplant rejection. [source]

    Qualitative difference between the cytotoxic T,lymphocyte responses to melanocyte antigens in melanoma and vitiligo

    EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2005
    Belinda Palermo
    Abstract Vitiligo is a skin disorder characterized by depigmented macules secondary to melanocyte loss. An unusual facet is its relation to melanoma: Cytotoxic T,lymphocytes directed to melanocyte antigens are found in both conditions and imply a breakdown of tolerance, yet the resulting immune reaction is the opposite. The mechanisms at the basis of these opposite effects are not known. Here, we performed a direct comparison of whole melanocyte-specific T,cell populations in the two diseases. We demonstrate that neither precursor frequencies of Melan-A/MART-1-specific T,lymphocytes nor their status of activation differ significantly. However, by using a tetramer-based T,cell receptor down-regulation assay, we documented a higher affinity of vitiligo T,cells. We calculated that the peptide concentration required for 50% of maximal receptor down-regulation differed by 6.5-fold between the two diseases. Moreover, only vitiligo T,cells were capable of efficient receptor down-regulation and IFN-, production in response to HLA-matched melanoma cells, suggesting that this difference in receptor affinity is physiologically relevant. The differences in receptor affinity and tumor reactivity were confirmed by analyzing Melan-A/MART-1-specific clones established from the two diseases. Our results suggest that the quality, and not the quantity, of the melanocyte-specific cytotoxic responses differs between the two pathologies. [source]

    Recruitment of different subsets of antigen-presenting cells selectively modulates DNA vaccine-elicited CD4+ and CD8+ T lymphocyte responses

    EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 4 2004

    Abstract The immunogenicity of plasmid DNA vaccines may be limited by the availability of professional antigen-presenting cells (APC) at the site of inoculation. Here we demonstrate that the types of APC recruited to the injection site can selectively modulate CD4+ or CD8+ T lymphocyte responses elicited by an HIV-1 Env DNA vaccine in mice. Coadministration of plasmid GM-CSF with the DNA vaccine resulted in the recruitment of macrophages to the site of inoculation and specifically augmented vaccine-elicited CD4+ T lymphocyte responses. In contrast, coadministration of plasmid MIP-1, with the DNA vaccine resulted in the recruitment of dendritic cells to the injection site and enhanced vaccine-elicited CD8+ T lymphocyte responses. Interestingly, coadministration of both plasmid GM-CSF and plasmid MIP-1, with the DNA vaccine recruited both macrophages and dendritic cells and led to a synergistic and sustained augmentation of CD4+and CD8+ T lymphocyte responses. These data demonstrate the critical importance of locally recruited professional APC in determining the magnitude and nature of immune responses elicited by plasmid DNA vaccines. Moreover, these studies show that different subsets of professional APC can selectively modulate DNA vaccine-elicited T lymphocyte responses. [source]

    Regarding neutrophil and lymphocyte responses to oral Streptococcus in Adamantiades,Behçet's disease

    FEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 3 2006
    Cem Evereklioglu
    First page of article [source]

    Distinct MHC class I and II alleles are associated with hepatitis C viral clearance, originating from a single source

    HEPATOLOGY, Issue 1 2004
    Susan M. McKiernan
    The role of cytotoxic T lymphocyte responses, restricted by human leukocyte antigen (HLA) class I alleles, is recognized as highly significant in the successful clearance of hepatitis C virus (HCV). The frequency of class I alleles in females inoculated with HCV genotype 1b from a single source was examined for an association with outcome. Class I typing was performed using polymerase chain reaction sequence-specific primers in 227 female subjects: 141 had chronic infection and 86 had viral clearance. Statistical analysis included ,2 testing and multiple logistic regression analysis. A*03, B*27, and Cw*01 occurred more frequently in those with viral clearance (39.5%, 14%, and 9.3%, respectively) compared with those with chronic infection (19.1%, 2.1%, and 1.4%, respectively; P , .005). B*08 occurred more often in those with chronic infection compared with viral clearance (39.7% vs. 19.8%; P = .002). In combination with previously reported class II allele associations, over 75% that successfully eliminate HCV carry either A*03, DRB1*0101, or *0401, compared with only 37% of those with chronic infection (P < .0001). The haplotypes A*03-B*07-DRB1*15-DQB1*0602 and A*02-B*27-Cw*01-DRB1*0101-DQB1*0501 are associated with viral clearance (P = .004 and .01, respectively). By multiple logistic regression analysis, the alleles A*03, B*27, DRB1*0101, *0401, and *15 are associated with viral clearance, and B*27 has the strongest association (odds ratio [OR] 7.99). The haplotype A*01-B*08-Cw*07-DRB1*03011-DQB1*0201 is associated with chronic infection (P = .002), being independent for DQB1*0201 (OR 0.27). In conclusion, certain class I alleles are associated with outcome in this homogenous cohort. More significantly, either HLA-A*03, -DRB1*0101, or -*0401 are carried by an overwhelming majority of those subjects who successfully clear HCV. (HEPATOLOGY 2004;40:108,114.) [source]

    Activated B cells modified by electroporation of multiple mRNAs encoding immune stimulatory molecules are comparable to mature dendritic cells in inducing in vitro antigen-specific T-cell responses

    IMMUNOLOGY, Issue 2 2008
    Jaewoo Lee
    Summary Ex-vivo -activated B cells are an alternative source of antigen-presenting cells (APCs) and a potential replacement for dendritic cells (DCs) in immunotherapy. However, the ability of ex-vivo -activated B cells to function as potent APCs has been a concern, especially when compared to DCs. Our study investigated whether modification of activated B cells with immune stimulatory molecules could enhance the ability of activated B cells to stimulate T cells. We show that murine splenic B cells, activated with a combination of Toll-like receptor agonist and agonistic anti-CD40, stimulated antigen-specific CD8+ T cells more efficiently than cells activated with Toll-like receptor agonist or anti-CD40 alone, probably by down-regulation of the immune regulatory cytokine interleukin-10 (IL-10). However, the activated B cells were still poor T-cell stimulators compared to mature DCs. Therefore, we modified the activated B cells by simultaneous electroporation of multiple messenger RNAs encoding costimulatory molecules (OX40L and 4-1BBL), cytokines (IL-12p35 and IL-12p40) and antigen. We found that de novo expression or overexpression of OX40L, 4-1BBL and IL-12p70 on activated B cells synergistically enhanced proliferation as well as IL-2 and interferon-, production by CD8+ T cells. Furthermore, the RNA-modified activated B cells induced antigen-specific cytotoxic T lymphocyte responses as efficiently as mature DCs in vitro. Unexpectedly, modified activated B cells were inferior to mature DCs at in vivo induction of CD8+ T-cell responses. In summary, activated B cells modified to express immune stimulatory molecules are a potent alternative to DCs in immunotherapy. [source]

    Cover Picture , Mol.

    MOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 3 2009
    Nutr.
    Regular issues provide a wide range of research and review articles covering all aspects of Molecular Nutrition & Food Research. Selected topics of issue 3 are: An update on products and mechanisms of lipid peroxidation. Regulation of ,-catenin and connexin-43 expression: targets for sphingolipids in colon cancer prevention Modulation of the postprandial phase by ,-glucan in overweight subjects: Effects on glucose and insulin kinetics Probiotic bacteria are antagonistic to Salmonella enterica and Campylobacter jejuni and influence host lymphocyte responses in human microbiota-associated immunodeficient and immunocompetent mice [source]

    Abomasal lymph node responses to Haemonchus contortus intestinal antigens established in kid goats by infection or immunization with intestinal antigens

    PARASITE IMMUNOLOGY, Issue 2 2003
    Douglas P. Jasmer
    SUMMARY Immune responses to Haemonchus contortus intestinal antigens were evaluated using abomasal lymph node (ALN) lymphocytes from kid goats protected against challenge infection by immunization with parasite intestinal antigen, and from kids that were challenged after immunization with ovalbumin. ALN lymphocytes from the intestinal antigen-immunized group produced significantly higher antibody levels against intestinal antigens than the ovalbumin group, supporting the theory that immunization contributed to that ALN response. In contrast, intestinal lysates and membrane enriched preparations from intestinal cells stimulated significant proliferation of ALN lymphocytes in both groups. The proliferation was antigen-dependent, since intestinal antigens failed to stimulate proliferation in ALN lymphocytes from unimmunized and uninfected kids. For both the intestinal antigen and ovalbumin immunized groups, CD4+ T lymphocytes predominated in ALN lymphocytes that were stimulated to proliferate by intestinal antigens. The results indicate that H. contortus infection alone can induce ALN lymphocyte responses to intestinal antigens. In contrast to ALN lymphocyte responses, serum antibody against intestinal antigens was generally low to undetectable in ovalbumin-immunized kids following infection. Abomasal mucus from an H. contortus infected lamb was probed with a monoclonal antibody that binds to a periodate sensitive determinant on numerous H. contortus intestinal membrane and secreted proteins. Numerous bands of reactivity were detected, indicating that multiple parasite intestinal antigens were released into abomasal mucus during infection. The results, challenge the general concept that H. contortus intestinal antigens are ,hidden' from the host immune system during an infection. On the contrary, parasite intestinal proteins may be relatively abundant antigens presented to the host during infection. In addition, ALN T lymphocytes appear to provide a more sensitive measure than serum antibody to detect presentation of these antigens to the host immune system. [source]

    Stability of individual differences in cellular immune responses to two different laboratory tasks

    PSYCHOPHYSIOLOGY, Issue 6 2002
    Anna L. Marsland
    To explore the stability of immune reactivity across laboratory tasks, we correlated enumerative and functional lymphocyte responses to a speech task and a mental arithmetic task, delivered on the same occasion of testing in 31 healthy undergraduates. Both tasks were associated with an increase in peripheral CD8+ and CD56+ cell populations, and a decrease in proliferative response to phytohemagglutinin (PHA) and ratio of CD4:CD8 cells. Intertask correlations were significant for the magnitude of change in proliferative responses at two different concentrations of PHA, r= 0.76, p < .0001 and r= 0.46, p < .05, and in numbers of circulating CD56+ cells, r= 0.46, p < .005. Concomitant heart rate and systolic blood pressure responses also correlated significantly over the two experimental tasks (heart rate: r= 0.52 and systolic blood pressure: r= 0.58. ps < .0005). These data provide initial evidence that interindividual variability of some cellular immune responses is moderately reproducible across different stimulus conditions, providing further evidence that it may denote a stable individual difference. [source]

    Protein phosphorylation and kinome profiling reveal altered regulation of multiple signaling pathways in B lymphocytes from patients with systemic lupus erythematosus

    ARTHRITIS & RHEUMATISM, Issue 8 2010
    Taher E. Taher
    Objective The cause of B lymphocyte hyperactivity and autoantibody production in systemic lupus erythematosus (SLE) remains unclear. Previously, we identified abnormalities in the level and translocation of signaling molecules in B cells in SLE patients. The present study was undertaken to examine the extent of signaling abnormalities that relate to altered B cell responses in SLE. Methods B lymphocytes from 88 SLE patients and 72 healthy controls were isolated from blood by negative selection. Protein tyrosine phosphorylation and cellular kinase levels were analyzed by Western blotting, flow cytometry, and a kinome array protocol. Changes in protein phosphorylation were determined in ex vivo B cells and following B cell receptor engagement. Results Differences in tyrosine phosphorylation in B cells from patients with SLE, compared with matched controls, were demonstrated. Further, the kinome array analysis identified changes in the activation of key kinases, i.e., the activity of phosphatidylinositol 3-kinase, which regulates survival and differentiation, was up-regulated and the activity of Rac and Rho kinases, which regulate the cytoskeleton and migration, was increased. In contrast, the activity of ATR, which regulates the cell cycle, was down-regulated in SLE patients compared with controls. Differences in signaling pathways were seen in all SLE B lymphocyte subsets that manifested phenotypic features of immature, mature, and memory cells. Conclusion This study revealed dysregulation in multiple signaling pathways that control key responses in B cells of SLE patients. Data generated in this study provide a molecular basis for further analysis of the altered B lymphocyte responses in SLE. [source]

    Synovial lymphocyte responses to microbiologic antigen stimulation indicate the etiology of undifferentiated and reactive arthritis, and possibly of rheumatoid arthritis: Comment on the article by Schnarr et al

    ARTHRITIS & RHEUMATISM, Issue 8 2002
    Denys K. Ford MD
    No abstract is available for this article. [source]

    Personalized peptide vaccines: A new therapeutic modality for cancer

    CANCER SCIENCE, Issue 10 2006
    Kyogo Itoh
    Therapeutic cancer vaccines have enjoyed little success so far, although many clinical trials have been conducted. Therefore, the creation of new protocols capable of inducing an objective response is required. We examined two of these protocols in the present review. The first is a personalized protocol to take into account the immunological diversity of cytotoxic T lymphocyte responses among patients. The second is a combination therapy designed to adapt to the presence of major histocompatibility complex (MHC)-loss cancer cells. The objective response rates of our classical (non-personalized) peptide vaccines were 0%, whereas that of personalized vaccines was 11.1% in the total advanced cancers and ,20% in malignant glioma and cervical cancers, respectively. A ,50% decrease in serum prostate-specific antigen (PSA) was seen in 8.7% of advanced hormone refractory prostate cancer patients by personalized vaccination alone, whereas such a decrease was seen in 54% of patients when the personalized vaccination was combined with a low dose of estramustine. Based on these experiences, we propose a personalized peptide vaccine combined with chemotherapy as a new treatment modality for cancers. (Cancer Sci 2006; 97: 970,976) [source]

    Interferon regulatory factor-1 acts as a powerful adjuvant in tat DNA based vaccination,

    JOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2010
    Arianna Castaldello
    Genetic vaccines are safe cost-effective approaches to immunization but DNA immunization is an inefficient process. There is, therefore, a pressing need for adjuvants capable of enhancing the immunogenicity and effectiveness of these vaccines. This is particularly important for diseases for which successful vaccines are still lacking, such as cancer and infectious diseases including HIV-1/AIDS. Here we report an approach to enhance the immunogenicity of DNA vaccines involving the use of transcription factors of the Interferon regulatory factor (IRF) family, specifically IRF-1, IRF-3, and IRF-7 using the tat gene as model antigen. Balb/c mice were immunized by three intramuscular inoculations, using a DNA prime-protein boost protocol, with a DNA encoding tat of HIV-1 and the indicated IRFs and immune responses were compared to those induced by vaccination with tat DNA alone. In vivo administration of plasmid DNA encoding IRF-1, or a mutated version of IRF-1 deleted of the DNA-binding domain, enhanced Tat-specific immune responses and shifted them towards a predominant T helper 1-type immune response with increased IFN-, production and cytotoxic T lymphocytes responses. Conversely, the use of IRF-3 or IRF-7 did not affect the tat -induced responses. These findings define IRF-1 and its mutated form as efficacious T helper 1-inducing adjuvants in the context of tat- based vaccination and also providing a new promising candidate for genetic vaccine development. J. Cell. Physiol. 224: 702,709, 2010. © 2010 Wiley-Liss, Inc. [source]