Search results for "Lymphocyte culture"
showing 10 items of 26 documents
Lysis of human pancreatic adenocarcinoma cells by autologous HLA-class I-restricted cytolytic T-lymphocyte (CTL) clones.
1993
From the primary site of a pancreatic adenocarcinoma (patient BE) a permanent cell line (MZ-PC-2) was established in tissue culture. In the course of mixed lymphocyte-tumor-cell cultures (MLTC) with autologous blood-derived lymphocytes, we isolated CTL clones that lysed autologous tumor cells but not autologous EBV-transformed B cells (EBV-B) and not K562. Pre-treatment of MZ-PC-2 cells with IFN-gamma was required to obtain significant lysis in 4-hr cytotoxicity assays. IFN-gamma was superior to IFN-alpha in that respect. Among MLTC responder lymphocytes, tumor-reactive CTL proliferated more strongly in response to MZ-PC-2 cells treated with IFN-gamma than to untreated tumor cells. Three CT…
The monocytic population in chronic lymphocytic leukemia shows altered composition and deregulation of genes involved in phagocytosis and inflammatio…
2013
Macrophages reside in tissues infiltrated by chronic lymphocytic leukemia B cells and the extent of infiltration is associated with adverse prognostic factors. We studied blood monocyte population by flow cytometry and whole-genome microarrays. A mixed lymphocyte reaction was performed to evaluate proliferation of T cells in contact with monocytes from patients and normal donors. Migration and gene modulation in normal monocytes cultured with CLL cells were also evaluated. The absolute number of monocytes increased in chronic lymphocytic leukemia patients compared to the number in normal controls (792 +/- 86 cells/mu L versus 485 +/- 46 cells/mL, P=0.003). Higher numbers of non-classical CD…
Peripheral blood dendritic cells are phenotypically and functionally intact in chronic hepatitis B virus (HBV) infection
2007
Summary Persistence of hepatitis B virus (HBV) infection is associated with reduced anti-viral T cell responses. Impaired dendritic cell (DC) function was suggested as the cause of reduced T cell stimulation in chronic HBV carriers. Thus, we compared myeloid (mDC) and plasmacytoid DC (pDC) from chronic HBV carriers and controls. Frequency and phenotype of isolated DC were analysed by fluorescence activated cell sorter staining, DC function by mixed lymphocyte reaction, cytokine bead array, intracellular cytokine staining, enzyme-linked immunosorbent assay and enzyme-linked immunospot. Expression of HBV DNA and mRNA was studied by polymerase chain reaction (PCR). Circulating total DC, mDC or…
Stimulation of T cells by autologous mononuclear leukocytes and epidermal cells in psoriasis.
1986
Based on reports suggesting aberrant cell-mediated immunity and altered infiltration of immunocompetent cells into the skin in psoriasis, we studied the stimulation of T cells by autologous non-T mononuclear leukocytes (autologous mixed lymphocyte reaction, AMLR) and by epidermal cells isolated from lesional and clinically uninvolved skin in psoriasis (autologous mixed epidermal cell lymphocyte reaction, AMECLR). Age- and sex-matched individuals served as controls. We found that the AMLR in psoriasis (n = 11) was similar to that in healthy controls (n = 16); furthermore, cell proliferation was alike in the presence of either 5% AB-serum or autologous serum. By contrast, while the AMECLR in …
Chronic T cell leukemia with unusual cellular characteristics in ataxia telangiectasia
1986
Abstract A 27-year-old male patient with ataxia telangiectasia (AT) developed atypical chronic lymphocytic leukemia with increasing bone marrow infiltration in the absence of organomegaly. One-third of the leukemia cells expressed a mature suppressor/cytotoxic T cell phenotype (T3+ T4- T6- T8+ T10-), two-thirds demonstrated additional helper/inducer T cell- associated antigens (T3+ T4+ T6- T8+ T10-), and a small fraction reacted with a natural killer (NK) cell-specific monoclonal antibody (Leu 11+). The proliferative response to stimulation in vitro with lectins and various monoclonal antibodies resembled the proliferation pattern of mature thymocytes: The cells responded to phytohemaggluti…
Long-Term Human CD34+ Stem Cell-Engrafted Nonobese Diabetic/SCID/IL-2Rγnull Mice Show Impaired CD8+ T Cell Maintenance and a Functional Arrest of Imm…
2010
Abstract Allogeneic hematopoietic stem cell transplantation represents the most effective form of immunotherapy for chemorefractory diseases. However, animal models have been missing that allow evaluation of donor-patient–specific graft-versus-leukemia effects. Thus, we sought to establish a patient-tailored humanized mouse model that would result in long-term engraftment of various lymphocytic lineages and would serve as a donor-specific surrogate. Following transfer of donor-derived peripheral blood stem cells into NOD/SCID/IL-2Rγnull (NSG) mice with supplementation of human IL-7, we could demonstrate robust engraftment and multilineage differentiation comparable to earlier studies using …
Proteasome-inhibited dendritic cells demonstrate improved presentation of exogenous synthetic and natural HLA-class I peptide epitopes.
2004
The design and successful clinical implementation of cancer vaccines targeting the induction of T-cell mediated immunity is a rapidly evolving field that is hampered by an empirical selection of antigen and adjuvant. In particular, vaccines using defined tumor-associated peptide epitopes elicit only a restricted T-cell repertoire in a minority of patients. In this regard, vaccines comprising the whole spectrum of antigens presented by individual autologous tumors would be advantageous. In an in vitro model, we evaluated the capacity of naturally processed Epstein-Barr virus-transformed B-lymphoblastoid-cell line (LCL)-derived peptides to activate virus-specific CD8+ T cells of seropositive …
JAK3/STAT5/6 Pathway Alterations Are Associated with Immune Deviation in CD8+ T Cells in Renal Cell Carcinoma Patients
2010
To investigate the molecular mechanisms underlying altered T cell response in renal cell carcinoma (RCC) patients, we compared autologous and allogeneic CD8(+) T cell responses against RCC line from RCC patients and their HLA-matched donors, using mixed lymphocyte/tumor cell cultures (MLTCs). In addition, we analyzed the expression of molecules associated with cell cycle regulation. Autologous MLTC responder CD8(+) T cells showed cytotoxic activity against RCC cell lines; however the analysis of the distribution of CD8(+) T-cell subsets revealed that allogenic counterparts mediate superior antitumor efficacy. In RCC patients, a decreased proliferative response to tumor, associated with defe…
T cell-mediated cytotoxicity: discrimination between antigen recognition, lethal hit and cytolysis phase.
1974
Using a 51Cr release cytotoxicity assay, the cytotoxic effector phase of in vitro activated mouse T lymphocytes (killer cells) against 51Cr-labeled target cells has been investigated. It is shown that within 5–10 minutes of contact between killer cells and target cells, the target cells are already committed to lysis, therefore, antigen recognition and “lethal hit” must have taken place within this period of time. In contrast, target cell lysis (cytolysis phase) requires up to 3–4 h in order to be completed; it occurs independently of killer cells and it is highly temperature dependent. The killer cell-dependent phase (antigen-recognition and “lethal hit”) is dissociated into two consecutiv…
CD4 monoclonal antibody VIT4 in human alloimmune response in vitro and in vivo.
1996
In the present report the immunosuppressive effects of the murine anti-human CD4 monoclonal antibody (mAb) VIT4 on human alloimmune response in vitro were analyzed. Moreover, the antibody was tested for its activity to prolong allograft survival in seven patients with steroid-refractory allograft rejection. VIT4 inhibited the proliferative response to alloantigens in the mixed lymphocyte reaction (MLR) in a dose-dependent manner. At concentrations of 1 and 10 micrograms/ml VIT4 blocked MLR by 55 +/- 11% and 77 +/- 1%, respectively. Also alloantigen-specific proliferation of in vitro- generated memory T cells was dose-dependently reduced to 23 +/- 1% at a VIT4 concentration of 100 micrograms…