Search results for "hemic and immune systems"
showing 10 items of 340 documents
Monocytes/Macrophages Are the Major Targets of the CCL3 Chemokine Produced by CD38(+)CD49d(+) Chronic Lymphocytic Leukemia Cells
2009
Abstract Abstract 2350 Poster Board II-327 Introduction: CD38 and CD49d are associated negative prognosticators in chronic lymphocytic leukemia (CLL). Recent gene expression profiling studies comparing CLL cases expressing low versus high levels of CD38 and CD49d, identified CCL3 as a gene upregulated by CD38+CD49d+ CLL. The release of CCL3 by cultured CLL cells was also demonstrated upon CD38 triggering, and CCL3 protein was found in CLL cells from bone marrow biopsies (BMB) of CD38+ cases (Zucchetto et al., Cancer Res, 2009; 69:4001-9). Given the role of CCL3 as potent chemoattractant for different cell types, we aimed at identifying the major targets of CCL3, as produced by CD38+CD49d+ C…
Clinical Course and Significance of the Novel FLT3-Y842C Mutation in a Patient with AML Treated with PKC412 Monotherapy.
2004
Abstract We recently identified a novel mutation (Y842C) within the tyrosine kinase domain of FLT3 in a patient treated with PKC410 monotherapy (ASH 2003, # 4681). Here, we present follow up studies including the clinical course of the patient and frequency analysis in 110 patients with AML. In addition, we characterized the novel mutation using overexpression of FLT3-Y842C in 32D cells. AML M2 was diagnosed in a 63 year old, male patient in 1993. After having experienced his second relapse upon standard therapy the patient was refractory to alemtuzumab treatment. Due to reduced performance status the patient was not eligible to standard chemotherapy and was enrolled into a phase II trial i…
Alloreactive and H-2-restricted Lyt 23 cytotoxic T lymphocytes derive from a common pool of antecedent Lyt 123 precursors.
1980
If the collaborative requirement of Lyt 1 T helper cells is bypassed by the Lyt 1 T cell-derived mediator of T help, termed Il-2, upon antigenic stimulation, PNA+ Lyt 123 thymocytes differentiate into either alloreactive or H-2-restricted PNA- Lyt 23 cytotoxic effector cells. Along the differentiation pathway from Lyt 123 leads to 23 effector cells, cytolytic activity is carried out by T cells that still express the Lyt 123 phenotype. The data establish that Lyt 23 CTL are produced by differentiation from antecedent Lyt 123 cells.
Precursor frequency can compensate for lower TCR expression in T cell competition during priming in vivo.
2006
The factors controlling clonal dominance of cytotoxic T lymphocyte (CTL) responses are currently not well understood. To study the functional impact of the strength of the interaction of a T cell with an antigen-presenting cell in this context, we established a new mouse model comprised of two T cell receptor (TCR)-transgenic strains expressing the identical TCR in differing amounts, hence providing two CTL clones with different avidities but identical specificity and affinity. Utilizing this new model, we show that upon antigen challenge higher-avidity CTL expand at the expense of moderate-avidity CTL in vivo if present in equal numbers. Beyond this, moderate-avidity T cells can also contr…
The T Cell Receptor (TCR) in HLA-B27-Restricted T Cell Responses - an Introduction
1996
Recent data indicate that cytotoxic T lymphocytes (CTL) are involved in the pathogenesis of HLA-B27-associated spondylarthropathies. In the absence of clearly defined "arthritogenic" bacterial or self peptides that are presented by HLA-B27 and recognized by such CD8+CTL, one approach has been to investigate the T cell repertoire of lesional cellular infiltrates by determining T cell receptor (TCR) variable (V) gene segment frequencies. Furthermore, the TCR V alpha and V beta chains of HLA-B27-restricted CTL clones, notably the putative peptide-contacting CDR3-regions of these TCRs, have been sequenced. This article will give a short review of the current literature on the topology of the TC…
Fine specificity and cytolytic activity of continuously growing alloreactive cytotoxic T lymphocyte clones.
1980
The role of Lyt 1+ T-cell-derived secondard CTL inducing factor allowed the cloning of alloreactive cytotoxic T lymphocytes (CTL) by the limiting dilution approach. Several monoclonal cell lines were established in vitro. The lytic activity of some of the cell lines exceeded that of CTL from bulk cultures; that is, 50% of the target cells were lysed at an effector to target cell ratio of 0.04:1. The fine specificity of individual CTL clones is discussed.
Herpes-Simplex-virus-specific, H-2Dk-restricted T lymphocytes bear receptors for H-2Dd alloantigen.
1980
Cytotoxic T lymphocytes generated in the course of an HSV-infection of CBA (H-2k) mice not only lyse syngeneic, virus-infected target cells but also cross-react with noninfected taraget cells expressing the Dd alloantigen. On the effector cell level, this alloreactivity is mediated by virus-specific CTL's that are restricted to H-2Dk determinants. On the prekiller cell level, the anti-HSV-reactive T cells exhibiting cross-reactivity for Dd alloantigen could be positively selected on H-2d spleen-cell monolayers. After differentiation into cytolytic effector cells, target cells expressing Dd alloantigens and syngeneic HSV-infected target were lysed with equal efficiency. The results imply tha…
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),…
Internet Gaming Disorder profiles and their associations with social engagement behaviours.
2021
Abstract Internet Gaming Disorder (IGD), describes the abuse of Internet games with detrimental impact to the real-life social engagement of some gamers. Indeed, evidence suggests that gamers differ on the severity and way in which they express IGD symptoms, as well as their social engagement behaviours. The present study aimed to: a) profile gamers regarding their experience of IGD symptoms and; b) examine how different IGD profiles varied on social engagement behaviours. Methods: A sample consisting of 1032 gamers (18–72 years, Mage = 24) was assessed with the Internet Gaming Disorder Scale 9 Items Short Form (IGDS9-SF) and social engagement questions regarding their participation in empl…