Search results for "Cytotoxic"

In Vivo Protective Effect of Tumour Necrosis Factor   Against Experimental Infection with Herpes Simplex Virus Type 1

1991

C57BL/6 mice, which differ genetically from other strains by their resistance to herpes simplex virus type 1 (HSV-1) infection, were inoculated intraperitoneally with different doses of tumour necrosis factor alpha (TNF-alpha). Mice pretreated with 100 ng, or even 10 ng, of TNF-alpha showed prolonged survival compared to control mice that were infected with 10(7) p.f.u. of HSV-1. Significant protection was observed in mice injected 4 or 8 h prior to or after HSV-1 inoculation, respectively. Protection was also observed when mice which differed at their H-2 locus were treated with TNF-alpha after infection with HSV-1. Interferon could not be detected in the sera of mice at different time poi…

Targeting positive regulatory domain I-binding factor 1 and X box-binding protein 1 transcription factors by multiple myeloma-reactive CTL.

2005

Abstract Growing evidence indicates that multiple myeloma (MM) and other malignancies are susceptible to CTL-based immune interventions. We studied whether transcription factors inherently involved in the terminal differentiation of mature B lymphocytes into malignant and nonmalignant plasma cells provide MM-associated CTL epitopes. HLA-A*0201 (A2.1) transgenic mice were used to identify A2.1-presented peptide Ag derived from the plasma cell-associated transcriptional regulators, positive regulatory domain I-binding factor 1 (PRDI-BF1) and X box-binding protein 1 (XBP-1). A2.1-restricted CTL specific for PRDI-BF1 and XBP-1 epitopes efficiently killed a variety of MM targets. PRDI-BF1- and X…

Impact of thymus on the generation of immunocompetence and diversity of antigen-specific MHC-restricted cytotoxic T-lymphocyte precursors.

1981

RNA Transfer by Electroporation into Mature Dendritic Cells Leading to Reactivation of Effector-Memory Cytotoxic T Lymphocytes: A Quantitative Analys…

2005

Previous studies have analyzed transfer of RNA-encoded tumor-associated antigens (TAAs) into immature dendritic cells (DCs) because of their exceptional ability to internalize antigens. Concerns have been raised regarding the use of immature DCs in clinical studies because of their capacity to tolerize T cells. Therefore, we focused on optimizing RNA transfer into mature DCs using the method of electroporation and obtained high protein expression in 90% of mature DCs. Particular emphasis was placed on quantifying RNA transfer. Reconstitution of peptide-MHC (pMHC) ligands on RNA-pulsed DCs was measured with the help of effector-memory cytotoxic T lymphocytes (CTLs) specific for the melanoma-…

T-cell-derived helper factor allows Lyt 123 thymocytes to differentiate into cytotoxic T lymphocytes.

1979

IT is generally accepted that the diversity of T-cell responsiveness is generated in the thymus1. It is also known that except for a few Lyt 1 cells all thymocytes express the Lyt 123 phenotype2,3. Surprisingly, thymocytes are poorly responsive in vitro4, and only the medullary thymocytes, comprising 5–10% of the total thymic cell population, show an in vitro responsiveness comparable with that of peripheral T cells5. Cortical thymocytes, comprising 90–95% of all thymocytes, have previously been considered to be immature and immunologically incompetent4. The result reported here show that thymocytes are able to generate alloantigen-, virus- and hapten-specific cytotoxic T lymphocytes (CTL),…

T lymphocyte control of autoreactivity: analysis with human T cell clones and limiting dilution culture

1986

To investigate cellular mechanisms controlling activated autoreactive T lymphocytes, a limiting dilution system was established employing cloned autoreactive major his-tocompatibility complex class II specific lymphocytes (a2/7) as stimulator cells for autologous peripheral blood mononuclear cells. At low responder/stimulator ratios, cytotoxic effector cells were generated capable of lysing clone a2/7. Importantly, within the population of cells mediating autocytotoxic effector function, differential specificities were found to exist. The generation of such autocytotoxic T lymphocytes appears to be inhibited by an additional population of cells circulating at lower frequency suggesting that…

Cytotoxicity of tumor antigen specific human T cells is unimpaired by arginine depletion.

2013

Tumor-growth is often associated with the expansion of myeloid derived suppressor cells that lead to local or systemic arginine depletion via the enzyme arginase. It is generally assumed that this arginine deficiency induces a global shut-down of T cell activation with ensuing tumor immune escape. While the impact of arginine depletion on polyclonal T cell proliferation and cytokine secretion is well documented, its influence on chemotaxis, cytotoxicity and antigen specific activation of human T cells has not been demonstrated so far. We show here that chemotaxis and early calcium signaling of human T cells are unimpaired in the absence of arginine. We then analyzed CD8(+) T cell activation…

Effects of Short- and Long-term Ultraviolet B Irradiation on the Immune System of the Common Carp (Cyprinus carpio)¶

2005

Carp (Cyprinus carpio) were repeatedly exposed to 0, 60, 120 and 240 mJ/cm2 ultraviolet B (UVB) radiation three times in 1 week (short-term exposure) or 12 times in 4 weeks (long-term exposure). The effect of UVB on the functioning of the carp immune system was studied on day 2 after the final irradiation. After short-term UVB exposure, the whole-blood respiratory burst and cytotoxic activity were markedly enhanced, with parallel responses in both the number of circulating granulocytes and in the plasma cortisol concentration of the fish. These changes were not detectable after long-term exposure. The respiratory burst by head kidney granulocytes was suppressed dose dependently after both e…

γδ T cell-based anticancer immunotherapy: Progress and possibilities

2015

Comparative Antitumor Effect of Preventive versus Therapeutic Vaccines Employing B16 Melanoma Cells Genetically Modified to Express GM-CSF and B7.2 i…

2012

Cancer vaccines have always been a subject of gene therapy research. One of the most successful approaches has been working with genetically modified tumor cells. In this study, we describe our approach to achieving an immune response against a murine melanoma model, employing B16 tumor cells expressing GM-CSF and B7.2. Wild B16 cells were injected in C57BL6 mice to cause the tumor. Irradiated B16 cells transfected with GM-CSF, B7.2, or both, were processed as a preventive and therapeutic vaccination. Tumor volumes were measured and survival curves were obtained. Blood samples were taken from mice, and IgGs of each treatment group were also measured. The regulatory T cells (Treg) o…