Search results for "Killer Cell"

Prospective Study of the Evolution of Blood Lymphoid Immune Parameters during Dacarbazine Chemotherapy in Metastatic and Locally Advanced Melanoma Pa…

2014

BackgroundThe importance of immune responses in the control of melanoma growth is well known. However, the implication of these antitumor immune responses in the efficacy of dacarbazine, a cytotoxic drug classically used in the treatment of melanoma, remains poorly understood in humans.MethodsIn this prospective observational study, we performed an immunomonitoring of eleven metastatic or locally advanced patients treated with dacarbazine as a first line of treatment. We assessed by flow cytometry lymphoid populations and their activation state; we also isolated NK cells to perform in vitro cytotoxicity tests.ResultsWe found that chemotherapy induces lymphopenia and that a significantly hig…

WHOLE BODY IRRADIATION INDUCES IFN-γ PRODUCTION IN BALB/c MICE BY PREVENTING THE APPEARANCE OF A Vα14+NK T DOWNREGULATORY POPULATION

2000

Lymph node cells from TNCB-immune BALB/c mice fail to produce IFN-gamma when exposed to antigen in vitro. Conversely, lymph node cells of irradiated (550 rads) BALB/c mice produce IFN-gamma. Transfer experiments show that normal BALB/c mice contain cells which suppress IFN-gamma production. These downregulatory cells are CD4(+)alpha beta(+)and rearrange the invariant V alpha 14-J alpha 281 T cell receptor alpha chain, thus belonging to the NK T cell subset. Downregulatory cells probably act by producing IL-4 as their effect is blocked by mAb to IL-4.

Characterization of T–cell subclasses and NK–cells in lysosomal disorders by immuno–electron microscopy

1994

Previous studies have shown that B and T lymphocytes are affected in lysosomal disorders. The aim of this study was to investigate the involvement of subclasses of T lymphocytes and natural killer cells in lysosomal diseases. CD4+, CD8+, and CD56+ cells were immunomagnetically separated from peripheral blood mononuclear cells in 10 patients with various lysosomal diseases--including one patient each with infantile, late infantile, and juvenile neuronal ceroid-lipfuscinoses, two patients with mucopolysaccharidosis (MPS) type I and four patients with MPS type III, and one patient with mucolipidosis type II; all lymphocytes were studied by light and electron microscopy. Respective vacuolar or …

IL-2 receptor beta-chain signaling controls immunosuppressive CD4+ T cells in the draining lymph nodes and lung during allergic airway inflammation i…

2008

Abstract IL-2 influences both survival and differentiation of CD4+ T effector and regulatory T cells. We studied the effect of i.n. administration of Abs against the α- and the β-chains of the IL-2R in a murine model of allergic asthma. Blockade of the β- but not the α-chain of the IL-2R after allergen challenge led to a significant reduction of airway hyperresponsiveness. Although both treatments led to reduction of lung inflammation, IL-2 signaling, STAT-5 phosphorylation, and Th2-type cytokine production (IL-4 and IL-5) by lung T cells, IL-13 production and CD4+ T cell survival were solely inhibited by the blockade of the IL-2R β-chain. Moreover, local blockade of the common IL-2R/IL-15R…

Inhibition of anti-GD3-ganglioside antibody-induced proliferation of human CD8+ T cells by CD16+ natural killer cells

1994

The ganglioside GD3 has been described as a membrane component of human T cells which is involved in T cell growth. In the present study the activating function of GD3 for human CD4+ and CD8+ T cells was analyzed by five different monoclonal antibodies (mAb) directed against the GD3 molecule. Three mAb U5, Z21 and R24 induced strong proliferation of peripheral blood mononuclear cells and purified CD8+ and CD4+ T cells of normal donors containing less than 5% CD16+ natural killer (NK) cells. In contrast to CD4+ T cells, CD8+ T cells proliferated only weakly in the presence of 15% CD16+ NK cells. The proliferative response of purified CD4+ and CD8+ T cells (< 5% NK cells) correlated with the …

Immunotherapy with effector cells and IL-2 of lymph node metastases of human squamous-cell carcinoma of the head and neck established in nude mice

1999

We have previously reported that immune anti-tumor effector cells, both cytotoxic T lymphocytes (CTLs) and IL-2-activated natural killer (A-NK) cells, are effective at eliminating human head-and-neck cancer (HNC) targets in vitro and in vivo in xenograft models. In this study, these 2 types of human effector cell were compared for the ability to prevent the development of lymph node metastases in a metastasis model of human squamous-cell carcinoma of the head and neck (SCCHN) established in nude mice. A tumor cell line, OSC-19, was injected into the floor of the mouth in nude mice, and the tumor grew progressively and metastasized to cervical lymph nodes by day 21. As effector cells, a huma…

Induction of tumor-cell lysis by bi-specific antibody recognizing ganglioside GD2 and T-cell antigen CD3

1993

Human tumor cells expressing ganglioside GD2 were lysed by various effector populations targeted with an anti-CD3-anti-GD2 bi-specific antibody (BAb CD3 x GD2). This antibody-heteroconjugate was prepared by chemically cross-linking the OKT-3 monoclonal antibody (MAb) reactive with CD3 antigen on T lymphocytes with the ganglioside MAb ME 361, which binds preferentially to the tumor-associated ganglioside GD2. The specificity of target-cell lysis by the cytotoxic T cells (CTL) was mediated by the specificity of the targeting antibody: GD2-negative cells were not lysed in the presence of the CD3 x GD2 BAb. A dose-dependent response was observed in a range of 10 to 10,000 ng/ml. In contrast, 2 …

2004

Presence of the Transmembrane Protein Neuropilin in Cytokine-induced Killer Cells

2020

Background/aim Cytokine-induced killer (CIK) cells are a heterogenous population of immune cells showing promising applications in immunotherapeutic cancer treatment. Neuropilin (NRP) proteins have been proven to play an important role in cancer development and prognosis. In this study, CIK cells were tested for expression of NRPs, transmembrane proteins playing a role in the proliferation and survival of cancer cells. Materials and methods CIK cells were analyzed at different time points via flow cytometry and quantitative real-time polymerase chain reaction for neuropilin expression. Results Phenotyping results showed CIK cells having developed properly, and low levels of NRP2 were detect…

Bispecific antibodies targeting tumor-associated antigens and neutralizing complement regulators increase the efficacy of antibody-based immunotherap…

2015

The efficacy of antibody-based immunotherapy is due to the activation of apoptosis, the engagement of antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity (CDC). We developed a novel strategy to enhance CDC using bispecific antibodies (bsAbs) that neutralize the C-regulators CD55 and CD59 to enhance C-mediated functions. Two bsAbs (MB20/55 and MB20/59) were designed to recognize CD20 on one side. The other side neutralizes CD55 or CD59. Analysis of CDC revealed that bsAbs could kill 4-25 times more cells than anti-CD20 recombinant antibody in cell lines or cells isolated from patients with chronic lymphocytic leukemia. The pharmacokinetics of the bsAbs was evaluate…