scholarly journals Interleukin 2 and stimulator lymphoblastoid cells will induce human thymocytes to bind and kill K562 targets.

1982 ◽  
Vol 156 (5) ◽  
pp. 1545-1550 ◽  
Author(s):  
M Torten ◽  
N Sidell ◽  
S H Golub
Keyword(s):  
Cell Surface ◽  
B Cell ◽  
Cytotoxic Activity ◽  
Interleukin 2 ◽  
Target Cells ◽  
Maturation Process ◽  
Fc Gamma Receptor ◽  
Cytotoxic Cells ◽  
Gamma Receptor ◽  
Low Levels

Human thymocytes cultured in the presence of IL-2 and an irradiated B cell line became cytotoxic to K562 target cells. Thymocytes cultured alone or with only IL-2 exhibited almost no killing, but thymocytes cultured in the presence of stimulator cells alone exhibited low levels of cytotoxic activity. Removal of Fc gamma receptor-bearing cells from the activated thymocyte population almost completely abolished the binding and lytic activity. Separation of thymocytes into Fc microns+ and Fc microns-cells before culturing with IL-2 and stimulator cells revealed that only the Fc microns+ subpopulation developed into K562 killer cells. These findings indicate that modulation of Fc microns to Fc gamma receptors on the thymocyte cell surface is part of the maturation process of this particular subset of cytotoxic cells. Morphologically, most of the activated Fc gamma+ K562-binding cells were large, granulated lymphocytes. Only very few of the round, nongranulated small thymocytes were bound to K562 target cells.

scholarly journals Two pathways of exocytosis of cytoplasmic granule contents and target cell killing by cytokine-induced CD3+ CD56+ killer cells

Blood ◽  
1995 ◽  
Vol 86 (9) ◽  
pp. 3493-3499 ◽  
Author(s):  
BA Mehta ◽  
IG Schmidt-Wolf ◽  
IL Weissman ◽  
RS Negrin
Keyword(s):  
Cell Surface ◽  
Target Cell ◽  
Interleukin 2 ◽  
Cytoplasmic Granule ◽  
Target Cells ◽  
Killer Cells ◽  
Effector Cells ◽  
Surface Molecules ◽  
Cik Cells ◽  
Granule Release

Cytokine-induced killer (CIK) cells are non-major histocompatibility complex-restricted cytotoxic cells generated by incubation of peripheral blood lymphocytes with anti-CD3 monoclonal antibody (MoAb), interleukin-2 (IL-2), IL-1, and interferon-gamma. Cells with the greatest effector function in CIK cultures coexpress CD3 and CD56 surface molecules. CIK cell cytotoxicity can be blocked by MoAbs directed against the cell surface protein leukocyte function associated antigen-1 but not by anti-CD3 MoAbs. CIK cells undergo release of cytoplasmic cytotoxic granule contents to the extracellular space upon stimulation with anti-CD3 MoAbs or susceptible target cells. Maximal granule release was observed from the CD3+ CD56+ subset of effector cells. The cytoplasmic granule contents are lytic to target cells. Treatment of the effector cells with a cell-permeable analog of cyclic adenosine monophosphate (cAMP) inhibited anti-CD3 MoAb and target cell- induced degranulation and cytotoxicity of CIK cells. The immunosuppressive drugs cyclosporin (CsA) and FK506 inhibited anti-CD3- mediated degranulation, but did not affect cytotoxicity of CIK cells against tumor target cells. In addition, degranulation induced by target cells was unaffected by CsA and FK506. Our results indicate that two mechanisms of cytoplasmic granule release are operative in the CD3+ CD56+ killer cells; however, cytotoxicity proceeds through a cAMP- sensitive, CsA- and FK506-insensitive pathway triggered by yet-to-be- identified target cell surface molecules.

A Non-Internalizing Anti-CD40 Antibody, CHIR-12.12, Blocks CD40L-Induced Cytokine Production and Mediates Greater ADCC Than Rituximab in Primary CLL Cells.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2964-2964
Author(s):  
Xia Tong ◽  
Sharon Lea Aukerman ◽  
Karen Lin ◽  
Natasha Aziz ◽  
Cheryl Goldbeck ◽  
...  
Keyword(s):  
Cell Surface ◽  
B Cell ◽  
Cytokine Production ◽  
Ex Vivo ◽  
Lymphocytic Leukemia ◽  
Target Cells ◽  
Adcc Activity ◽  
Effector Cells ◽  
Cells Cultured

Abstract CD40 is expressed on chronic lymphocytic leukemia (CLL) cells, and CD40 activation leads to signaling critical for cell survival and proliferation. We have previously described a novel, fully human IgG1 anti-CD40 antagonistic monoclonal antibody, CHIR-12.12, generated in XenoMouse® mice (Abgenix, Inc.), and have demonstrated that it inhibits normal human B cell proliferation and survival and mediates potent antibody-dependent cellular cytotoxicity (ADCC) against primary CLL and non-Hodgkin’s lymphoma cells. In this study, we examined the ability of CHIR-12.12 to modulate cytokine production by primary CLL cells and compared the ADCC activity of CHIR-12.12 with rituximab against primary CLL cells. Primary CLL cells stimulated with CD40L produced a variety of cytokines, including IL-10, TNF-α , IL-8, GM-CSF, IL-6, MCP-1, and MIP-1β. Addition of CHIR-12.12 to primary CLL cells inhibited CD40L-mediated production of these cytokines. Cytokine production by primary CLL cells cultured with CHIR-12.12 alone in the absence of CD40L did not exceed levels produced by CLL cells cultured in medium. These data suggest that CHIR-12.12 is a potent antagonist for CD40L-mediated cytokine production by primary CLL cells and shows no agonistic activity by itself. We next compared the relative ADCC activity of CHIR-12.12 and rituximab against ex vivo primary CLL cells from 8 patients. CHIR-12.12 exhibited greater ADCC than rituximab against CLL cells from all patients. The average percent of maximum lysis by CHIR-12.12 and rituximab were 49 ± 16% and 31 ± 14%, respectively. CHIR-12.12 was greater than 10-fold more potent than rituximab, as measured by ED50 values (14.1 pM versus 155.5 pM, respectively). Quantitative CD20 and CD40 density on CLL cells and the degree of antibody internalization were investigated as potential reasons for the difference in ADCC activity. The greater ADCC potency and efficacy of CHIR-12.12 was not dependent on a higher density of cell surface CD40 molecules, as there were 1.3 to 14-fold higher numbers of CD20 than CD40 molecules on the cell surface. Antibody internalization studies using primary CLL cells conducted by flow cytometry and confocal microscopy show that upon binding to CD40 at 37°C, CHIR-12.12 remains uniformly distributed on the cell surface, even after 3 hours. In contrast, after binding at 37°C, rituximab is redistributed into caps and internalized. These data suggest that the potent ADCC activity of CHIR-12.12 may be partly related to its ability to remain on the surface of target cells uniformly, allowing optimal interaction with effector cells. Taken together, these results suggest that CHIR-12.12 may be effective at mediating potent ADCC against CLL cells in vivo. CHIR-12.12 is currently in Phase I trials for B-cell malignancies.

scholarly journals The Ligand-binding Domain of CD22 Is Needed for Inhibition of the B Cell Receptor Signal, as Demonstrated by a Novel Human CD22-specific Inhibitor Compound

2002 ◽  
Vol 195 (9) ◽  
pp. 1207-1213 ◽  
Author(s):  
Soerge Kelm ◽  
Judith Gerlach ◽  
Reinhard Brossmer ◽  
Claus-Peter Danzer ◽  
Lars Nitschke
Keyword(s):  
B Cells ◽  
Cell Surface ◽  
Ligand Binding ◽  
B Cell ◽  
Intracellular Signaling ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Negative Regulator ◽  
Target Cells ◽  
Lectin Domain

CD22 is a B cell–specific transmembrane protein of the Siglec family. It binds specifically to α2,6-linked sialic acid (Sia) residues, which are also present on glycoproteins on the B cell surface. CD22 acts as a negative regulator in B cell receptor–mediated signaling by recruitment of Src homology 2 domain–containing tyrosine phosphatase (SHP)-1 to its intracellular tail. To analyze how ligand-binding of CD22 influences its intracellular signaling domain, we designed synthetic sialosides as inhibitors for the lectin domain of CD22. One of these compounds inhibited binding of human CD22-Fc to target cells over 200-fold better than Sia and was highly selective for human CD22. When Daudi cells or primary B cells were stimulated with anti-immunoglobulin (Ig)M in presence of this sialoside inhibitor, a higher Ca2+ response was observed, similar to CD22-deficient B cells. Accordingly, a lower tyrosine-phosphorylation of CD22 and SHP-1 recruitment was demonstrated in presence of the sialoside. Thus, by interfering with ligand binding of CD22 on the B cell surface, we have shown for the first time that the lectin domain of CD22 has a direct, positive influence on its intracellular inhibitory domain. Also, we have developed a novel low molecular weight compound which can enhance the response of human B cells.

Specific cytotoxic activity of T lymphocyte clones derived from a patient with gliosarcoma

1988 ◽  
Vol 69 (5) ◽  
pp. 751-759 ◽  
Author(s):  
Shin-Ichi Miyatake ◽  
Haruhiko Kikuchi ◽  
Kohichi Iwasaki ◽  
Junkoh Yamashita ◽  
Yuzirou Namba ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Cytotoxic Activity ◽  
Tumor Cells ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Interleukin 2 ◽  
Target Cells ◽  
Autologous Tumor ◽  
Lymphokine Activated Killer Cells ◽  
Recombinant Interleukin 2

✓ Eleven lymphocyte clones were established from the peripheral blood lymphocytes of a patient with gliosarcoma by means of autologous tumor stimulation and the limiting-dilution technique with recombinant interleukin-2. Ten of the 11 clones were cytotoxic against the autologous tumor cell line GI-1. Seven of the 10 clones were also cytotoxic against allogeneic brain-tumor lines and HeLa cells, one clone was cytotoxic against several target cells, and two clones were specifically cytotoxic against GI-1 and allogeneic brain-tumor cells. One of the 11 clones was not cytotoxic against any target cells tested. Lymphokine-activated killer cells induced by recombinant interleukin-2 alone exhibited cytotoxic activity against all target tumor cells tested. Surface phenotypic analysis revealed that all lymphocyte clones expressed CD3 antigen, some expressed CD4 antigen, and others expressed CD8 antigen. These clones seemed to be antigen-specific cytotoxic T lymphocyte clones. Analysis with these antigen-specific cytotoxic T lymphocyte clones may be useful in the elucidation of tumor-specific or tumor-associated antigens on autologous tumor cells.

scholarly journals Fc gamma receptor II (CD32) on malignant B cells influences modulation induced by anti-CD19 monoclonal antibody

Blood ◽  
1994 ◽  
Vol 83 (6) ◽  
pp. 1632-1639
Author(s):  
SF Vervoordeldonk ◽  
PA Merle ◽  
EF van Leeuwen ◽  
CE van der Schoot ◽  
AE von dem Borne ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
B Cells ◽  
B Cell ◽  
Cell Line ◽  
B Cell Malignancies ◽  
Antigenic Modulation ◽  
Fc Gamma Receptor ◽  
Gamma Receptor ◽  
Modulation Rate ◽  
Switch Variant

Antigenic modulation is one of many factors determining the effectiveness of monoclonal antibody (MoAb)-mediated therapy. To select the isotype of a CD19 MoAb most suitable for radioimmunotherapy of patients with B-cell malignancies, we studied the influence of MoAb isotype on modulation, after binding of the MoAb to different cell-line cells. The CD19-IgG1 MoAb was found to induce modulation of CD19 antigens on Daudi cell line cells more rapidly than did its IgG2a switch variant. We provide evidence that this difference in modulation rate is caused by the expression of Fc gamma receptor II (Fc gamma RII) on these cells. Experiments aimed at elucidating the mechanism of Fc gamma RII involvement in modulation induction by CD19-IgG1 showed that Fc gamma RII did not comodulate with CD19 MoAbs. However, cocrosslinking of CD19 and Fc gamma RII with CD19-IgG1 MoAb resulted in enhanced calcium mobilization in Daudi cells. This increased signal induction accompanies the enhanced capping and subsequent modulation of CD19 antigens. Because Fc gamma RII is expressed in varying densities on malignant B cells in all differentiation stages, our results have implications for the MoAb isotype most suitable for use in MoAb-based therapy of patients with B-cell malignancies.

scholarly journals Insertion of cytoplasmic tyrosine sequences into the nonphagocytic receptor Fc gamma RIIB establishes phagocytic function

Blood ◽  
1994 ◽  
Vol 83 (8) ◽  
pp. 2072-2080 ◽  
Author(s):  
ZK Indik ◽  
XQ Pan ◽  
MM Huang ◽  
SE McKenzie ◽  
AI Levinson ◽  
...  
Keyword(s):  
Tyrosine Phosphorylation ◽  
Receptor Activation ◽  
Molecular Structures ◽  
Fc Gamma Receptor ◽  
Gamma Receptor ◽  
Hematopoietic Lineage ◽  
Receptor Isoforms ◽  
Low Levels ◽  
Tyrphostin 23 ◽  
Receptor Family

Abstract Receptors for the Fc domain of IgG on cells of hematopoietic lineage perform important functions, including stimulation of the ingestion of IgG-coated cells. In examining the function of Fc gamma receptor isoforms by transfection into COS-1 cells, we have observed that Fc gamma RIIA induces the binding and phagocytosis of IgG-sensitized RBCs (EA) and that transfected COS-1 cells can serve as a model for examining the molecular structures involved in mediating a phagocytic signal. We now report that COS-1 cell transfectants expressing the isoforms Fc gamma RIIB1 and Fc gamma RIIB2 and a Fc gamma RIIA mutant without a cytoplasmic tail efficiently bind EA but do not mediate their phagocytosis. Furthermore, wild-type Fc gamma RIIA, but not Fc gamma RIIB1 or Fc gamma RBII2, was phosphorylated on tyrosine upon receptor activation. Tyrphostin 23, which alters tyrosine kinase activity, inhibited the phagocytosis of EA and reduced the phosphorylation of Fc gamma RIIA on tyrosine. Fc gamma RIIB1 and Fc gamma RIIB2 contain one copy of the cytoplasmic sequence YXXL/I implicated in signal transduction, whereas Fc gamma RIIA contains two copies. We therefore inserted YXXL/I sequences at different sites in Fc gamma RIIB2. Low levels of phagocytosis were observed in a Fc gamma RIIB2 mutant bearing the Fc gamma RIIA sequence YMTL and higher levels of phagocytosis were observed in a second Fc gamma RIIB2 mutant that contained both the upstream YMTL and an additional downstream tyrosine-containing motif. Activation of this mutant receptor also induced receptor tyrosine phosphorylation. Thus, these studies indicate that both the number and placement of YXXL sequences in the cytoplasmic domain of the Fc gamma RII receptor family affect both receptor tyrosine phosphorylation and phagocytic competence.

An ADCC-Independent Mechanism of Rituximab-Mediated B-NHL Cells Depletion Via Sensitization to Cell Death through the Expression of TRAIL on NK Cells

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4919-4919
Author(s):  
Mario I. Vega ◽  
Sara Huerta-Yepez ◽  
Melisa Martinez-Paniagua ◽  
Stavroula Baritaki ◽  
Benjamin Bonavida
Keyword(s):  
B Cell ◽  
Cytotoxic Activity ◽  
Nk Cells ◽  
Tumor Cells ◽  
Cell Lines ◽  
Fas Ligand ◽  
Cytotoxic Cells ◽  
Induced Apoptosis ◽  
Anti Cd20

Abstract Abstract 4919 Rituximab, a chimeric anti-CD20 mAb, has being used, alone or in combination with chemotherapy, in the treatment of patients with B-NHL and rheumatoid arthritis. It is also being tested clinically in the treatment of other B cell malignancies. The mechanisms by which the antibody depletes the B cells have been shown to be mediated via ADCC, CDC, and apoptosis. In addition, the antibody also signals the cells and modifies various survival pathways and sensitizes the resistant tumor cells to various apoptotic stimuli (Jazirehi and Bonavida, Oncogene 24:2121, 2005). The role of the host innate cytotoxic cells, such as NK cells, in cooperation with rituximab in the depletion of B-NHL cells has been poorly explored. Studies by us and others have reported that rituximab sensitizes resistant B-NHL tumor cells to both Fas ligand and TRAIL-induced apoptosis (Bonavida, Oncogene 26:3629, 2007; Daniel, D. et al., Blood 110:4037, 2007). Since NK cells express on the surface TRAIL, we hypothesized that rituximab may also sensitize the TRAIL-resistant tumor cells to NK-mediated cytotoxicity. Accordingly, we have examined various TRAIL-resistant B-NHL cell lines and used peripheral blood-derived purified human NK cells. Treatment of various B-NHL cell lines with rituximab sensitized the cells to TRAIL-induced apoptosis. The mechanism of TRAIL-induced cytotoxicity was found to be the result of TRAIL-induced inhibition of NF-κB and downstream inhibition of the DR5 transcription repressor Yin Yang 1 (YY1) as well as inhibition of anti-apoptotic gene products such as Bclxl. Treatment of various B-NHL cell lines with rituximab, unlike treatment with control IgG1, resulted in significant cytotoxicity in the presence of purified NK cells. The extent of the cytotoxic activity was a function of the E:T ratios used. We then examined the contribution of TRAIL expressed on the NK cell surface for its role in NK-mediated cytotoxicity of rituximab-pretreated B-NHL cells. We used a neutralizing TRAIL antibody that was added in the reaction mixture and demonstrated that the NK cytotoxic activity was significantly reduced compared to controls. These studies with rituximab were also confirmed with other CD20 mAbs. We are currently examining the sensitization of freshly-derived B-NHL and CLL cells that are treated with rituximab and other anti-CD20 mAbs to NK-mediated cytotoxicity for validation of the findings with cell lines. The present findings suggest that, in vivo, patients who are treated with rituximab may recruit NK and other effector cells to mediate, independently of ADCC, cytotoxicity via the TNF-family ligands (e.g. TNF-α, Fas-L, TRAIL). The studies also suggest that this B cell-depletion mechanism by NK cells may contribute to the mechanism of rituximab- mediated depletion of B-NHL cells in vivo. Noteworthy, the proposed host cytotoxic mechanism may not be functional if the therapeutic treatment consists of the combination of rituximab and immunosuppressive chemotherapeutic drugs that may lead to depletion or inactivation of host cytotoxic cells. Disclosures: No relevant conflicts of interest to declare.

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