Search results for "Immune system"
showing 10 items of 2885 documents
Jejunoileal bypass as the main procedure in the onset of immune-related conditions: the model of BADAS
2013
Bariatric surgery represents a common approach for the control of severe morbid obesity, reducing caloric intake by modifying the anatomy of the gastrointestinal tract. Following jejunoileal bypass, a large spectrum of complications has been described, with rheumatic manifestation present in up to 20% of cases. Although bowel bypass syndrome, also called blind loop syndrome, is a well-recognized complication of jejunoileal bypass, the same syndrome was recognized in patients who had not had intestinal bypass surgery, and the term the 'bowel-associated dermatosis-arthritis syndrome' (BADAS) was coined. The pathogenesis of BADAS is as yet poorly understood and only few data concerning this is…
Diplopod hemocyanin sequence and the phylogenetic position of the Myriapoda
2001
Hemocyanins are copper-containing respiratory proteins of the Arthropoda that have so far been thoroughly investigated only in the Chelicerata and the Crustacea but have remained unstudied until now in the Myriapoda. Here we report the first sequence of a myriapod hemocyanin. The hemocyanin of Spirostreptus sp. (Diplopoda: Spirostreptidae) is composed of two distinct subunits that are arranged in a 6 x 6 native molecule. The cloned hemocyanin subunit cDNA codes of for a polypeptide of 653 amino acids (75.5 kDa) that includes a signal peptide of 18 amino acids. The sequence closely resembles that of the chelicerate hemocyanins. Molecular phylogenetic analyses reject with high statistical con…
Nanosecond pulsed electric field inhibits malignant melanoma growth by inducing the change of systemic immunity
2019
Background Nanosecond pulsed electric fields (nsPEFs) showed an inhibitory effect on proliferation of malignant melanoma. In this study, the growth of melanoma were inhibited by changing the systemic immunity. Material and Methods C57BL/6 mice with B16 malignant were exposed to 200 pulses of 100 ns duration, 30kV/cm. The mice were executed four days later. T lymphocyte has been extracted from spleen. Cell viability was evaluated by CCK-8 assay. CD3+CD4+ T cells, CD3+CD8+ T cells, regulatory T cells (Treg) and myeloid-derived suppressor cells (MDSC) were analyzed by flow cytometry. TNF-α, IL-2, IL-10, TGF-β, IFN– γ levels in supernatants were assessed by ELISA. Results C57 malignant melanoma…
Side effect management during immune checkpoint blockade using CTLA-4 and PD-1 antibodies for metastatic melanoma – an update
2020
CTLA-4 and PD-1 play a key role in tumor-induced downregulation of lymphocytic immune responses. Immune checkpoint inhibitors have been shown to alter the immune response to various cancer types. Anti-CTLA-4 and anti-PD-1 antibodies affect the interaction between tumor, antigen-presenting cells and T lymphocytes. Clinical studies of the anti-CTLA-4 antibody ipilimumab and the anti-PD-1 antibodies nivolumab and pembrolizumab have provided evidence of their positive effects on overall survival in melanoma patients. Combined treatment using ipilimumab and nivolumab has been shown to achieve five-year survival rates of 52 %. Such enhancement of the immune response is inevitably associated with …
Dendritic cell-based immunotherapy of malignant melanoma: success and limitations.
2007
Dendritic cells (DC) are professional antigen-presenting cells in the immune system which are able to induce primary T-cell responses. Because of their central role in the initiation of immune responses, DC are an important tool for tumor-antigen-specific immunotherapy of cancer. DC vaccination using tumor-antigen-loaded DC has led to tumor regression in individual advanced-stage cancer patients. However, there is a discrepancy between strong and antigen-specific T cell responses in vaccinated cancer patients detectable ex vivo and only weak clinical responses. In most cases the immune system of advanced stage IV cancer patients allows only a temporary anti-tumor response and increasing evi…
Dacarbazine-mediated upregulation of NKG2D ligands on tumor cells activates NK and CD8 T cells and restrains melanoma growth.
2013
International audience; Dacarbazine (DTIC) is a cytotoxic drug widely used for melanoma treatment. However, the putative contribution of anticancer immune responses in the efficacy of DTIC has not been evaluated. By testing how DTIC affects host immune responses to cancer in a mouse model of melanoma, we unexpectedly found that both natural killer (NK) and CD8(+) T cells were indispensable for DTIC therapeutic effect. Although DTIC did not directly affect immune cells, it triggered the upregulation of NKG2D ligands on tumor cells, leading to NK cell activation and IFNγ secretion in mice and humans. NK cell-derived IFNγ subsequently favored upregulation of major histocompatibility complex cl…
Parvovirus H-1-Induced Tumor Cell Death Enhances Human Immune Response In Vitro via Increased Phagocytosis, Maturation, and Cross-Presentation by Den…
2005
Oncotropic and oncolytic viruses have attracted high attention as antitumor agents because they preferentially kill cancer cells in vitro and reduce the incidence of spontaneous, induced, or implanted animal tumors. Some autonomous parvoviruses (H-1, minute virus of mice) and derived recombinant vectors are currently under preclinical evaluation. Still not fully understood, their antitumor properties involve more than just tumor cell killing. Because wild-type parvovirus-mediated tumor cell lysates (TCLs) may trigger antigen-presenting cells (APCs) to augment the host immune repertoire, we analyzed phagocytosis, maturation, and crosspresentation of H-1-induced TCLs by human dendritic cells …
UV Exposure Boosts Transcutaneous Immunization and Improves Tumor Immunity: Cytotoxic T-Cell Priming through the Skin
2010
Immunologic approaches to combat cancer aim at the induction of tumor-reactive immune responses to achieve long-term protection. In this context, we recently developed a transcutaneous immunization (TCI) method using the Toll-like receptor (TLR) 7 agonist imiquimod and a peptide epitope. Application onto intact skin induces potent cytotoxic T lymphocyte (CTL) responses and protection against transplanted tumors. The purpose of this study was to explore the effects of UV irradiation on imiquimod-based TCI. Here we show that skin exposure to low-dose UV light before TCI with imiquimod strongly boosts specific CTL responses leading to memory formation and enhanced tumor protection. Toward the …
Altered intracellular sorting signals do not influence the efficacy of genetic melanoma vaccines incorporating helper determinants in mice.
2004
Background A genetic melanoma vaccine consisting of cDNA encoding the model self-antigen tyrosinase-related protein 2 (TRP2) fused in-frame to the immunogenic enhanced green fluorescent protein (EGFP) was able to break immune tolerance and stimulate CD8+ T cells in vivo. In the present study we investigated whether alteration of the intracellular antigen localization as a result of the linkage with immune-enhancing helper proteins affects the resulting immune response. Methods Expression plasmids and recombinant adenoviruses were constructed encoding various fusion proteins with different intracellular sorting signals which direct the antigen to the cytosol, the endoplasmic reticulum or the…
Overcoming the barrier of CD8+ T cells: Two types of nano-sized carriers for siRNA transport
2019
Abstract Bioengineering immune cells via gene therapy offers treatment opportunities for currently fatal viral infections. Also cell therapeutics offer most recently a breakthrough technology to combat cancer. These primary human cells, however, are sensitive to toxic influences, which make the utilization of optimized physical transfection techniques necessary. The otherwise commonly applied delivery agents such as LipofectamineⓇ or strongly cationic polymer structures are not only unsuitable for in vivo experiments, but are also highly toxic to immune cells. This study aimed to improve the design of polymeric carrier systems for small interfering RNA, which would allow efficient internali…