Search results for "Monoclonal antibody"

Isolation of naturally processed peptides recognized by cytolytic T lymphocytes (CTL) on human melanoma cells in association with HLA-A2.1.

1994

Cytolytic T lymphocyte (CTL) clones have previously been derived from peripheral blood of melanoma patient SK29(AV). They lyse autologous melanoma cells but not autologous Epstein-Barr virus (EBV)-transformed B lymphocytes. Immunoselection experiments indicate that these CTL clones recognize 4 different antigens (Aa, Ab, B, C) in association with a single HLA restriction element, HLA-A2.1. While the expression of antigens B and C appears to be confined to SK29-melanoma cells, antigens Aa and Ab are shared by a high proportion of allogeneic HLA-A2-positive melanoma lines. HLA-A2.1 and total HLA class I molecules have now been purified from SK29-melanoma cells using affinity chromatography an…

Membrane vesicles shed into the extracellular medium by human breast carcinoma cells carry tumor-associated surface antigens.

1995

We have compared the pattern of surface antigen expression, as detected by monoclonal antibodies (mAbs), in plasma membranes vs shed membrane vesicles of two human breast carcinoma cell lines, MCF-7 and 8701-BC. Antigen expression was detected on cells by immunofluorescence (IF) analysis, whilst, due to their small dimensions, the same technique was not applicable to vesicles. For these structures dot-blot analysis and immunoelectron microscopy (IEM) were employed. When applicable, both cell membranes and membrane vesicles were immunoprecipitated and the precipitate (IP) was analyzed by SDS-PAGE. Cells of both lines expressed HLA class I antigens, epithelial cytokeratins, β1 integrins, CEA …

AAZTA5-squaramide ester competing with DOTA-, DTPA- and CHX-A″-DTPA-analogues: Promising tool for 177Lu-labeling of monoclonal antibodies under mild …

2021

Abstract Background Combining the advantages of both cyclic and acyclic chelator systems, AAZTA (1,4-bis(carboxymethyl)-6-[bis(carboxymethyl)]amino-6-methylperhydro-1,4-diazepine) is well suited for complexation of various diagnostic and therapeutic radiometals such as gallium-68, scandium-44 and lutetium-177 under mild conditions. Due to its specificity for primary amines and pH dependent binding properties, squaric acid (SA) represents an excellent tool for selective coupling of the appropriate chelator to different target vectors. Therefore, the aim of this study was to evaluate radiolabeling properties of the novel bifunctional AAZTA5-SA being coupled to a model antibody (bevacizumab) i…

A first-in-human trial of RG7116, a glycoengineered monoclonal antibody targeting HER3, in patients with advanced/metastatic tumors of epithelial cel…

2013

2522 Background: The Human Epidermal Growth Factor Receptor 3 (HER3) is a key heterodimerization partner for other HER family members thereby acting as a downstream signal amplifier. This is a first in human study evaluating the safety of RG7116, a humanized anti-HER3 monoclonal antibody with potent HER3 signal inhibition. Due to a glycoengineered Fc-part this antibody displays enhanced antibody-dependent cellular cytotoxicity as compared to conventional antibodies. Methods: Patients (pts) with advanced or metastatic carcinomas with centrally confirmed HER3 protein expression were included. A “3+3” dose escalation design was performed starting at 100 mg flat dosing in a q2w regimen. In add…

Soluble biomarker signature to predict outcome of patients with non-small-cell lung cancer (NSCLC) treated with anti-PD1/PDL1 monoclonal antibodies.

2019

e20685 Background: Immunotherapy with anti-PD1/PDL1 monoclonal antibodies has become the second line standard treatment for most patients diagnosed of advanced Non-Small-Cell lung cancer (NSCLC). The aim of this study is to assess the utility of circulating biomarkers such as sPDL1, sPDL2, sCD137, sIDO, sTIM3, sCD28, sCD27, sCTLA4, sHVEM, sLAG3, sCD80 and sGITR for predicting efficacy of immunotherapy with anti-PD1/PDL1 therapies. Methods: Blood samples were collected before treatment from 50 NSCLC patients who received anti PD1/PDL1 therapies (second line). Plasma biomarkers´ levels were measured by Multiplex bead-based assays. Continuous variables were categorized using the median as a c…

?(1,3)Fucosyltransferase expression in E-selectin-mediated binding of gastrointestinal tumor cells

1996

E-selectin recognizes the oncofetal antigen sialyl-Lewis X, which is highly expressed in adenocarcinoma. Five α(1,3)fucosyltransferases (FT) have been cloned that confer cell-surface expression of sialyl-Lewis X on transfected cells. We show here that 12/18 gastrointestinal-tumor cell lines bind specifically to immobilized E-selectin and that in sialyl-Lewis-X-positive cells binding is inhibited with a monoclonal antibody against sialyl-Lewis X. Using RT-PCR, we determined the expression of the α(1,3)fucosyltransferases III, IV, V, VI and VII in gastrointestinal tumor cells. Transcripts of FT IV and FT VII are abundantly expressed in all tested cells. Therefore no single fucosyltransferase …

A bug in the resistance to EGFR inhibitors: is there a role for Mycoplasma and cytidine deaminase in reducing the activity of osimertinib in lung can…

2021

Quantitative monoclonal antibody determination of estrogen and progesterone receptors in human breast cancer: correlation with the radioligand method.

1994

To assess the possibility of substituting our routine method (dextran-coated charcoal, DCC) of determining estrogen (ER) and progesterone receptors (PR) for an enzyme immunoassay technique (EIA), we compared the two methods for determination of the two types of receptor in breast cancer specimens. In terms of sample positivity or negativity, the two techniques agreed in 76 of the 82 samples analyzed for ER (92.7%; p0.001), and in 65 out of 75 samples assayed for PR (86.6%; p0.001). Quantitative analysis of the data showed a significant correlation between DCC and EIA for both ER (r = 0.84; p0.0001) and PR (r = 0.77; p0.0001). The results suggest the usefulness of EIA in substituting DCC, al…

Targeting multiple myeloma with natural polyphenols

2019

Multiple myeloma (MM) is still an incurable hematologic malignancy. Although new therapeutic strategies have been developed to target different pathways in malignant cells, such as proliferation, differentiation, and apoptosis, better survival rates have also been achieved by the introduction of autologous stem cell transplantation (ASCT). Hematopoietic stem cell transplantation and novel targeted agents, such as proteasome inhibitors, monoclonal antibodies, immunomodulatory drugs, check-point inhibitors and epigenetic modulators, have significantly achieved long remission time and increased survival rates. However, most patients relapse, develop resistance, and eventually die because of re…

A specific CD4 epitope bound by tregalizumab mediates activation of regulatory T cells by a unique signaling pathway

2014

CD4(+)CD25(+) regulatory T cells (Tregs) represent a specialized subpopulation of T cells, which are essential for maintaining peripheral tolerance and preventing autoimmunity. The immunomodulatory effects of Tregs depend on their activation status. Here we show that, in contrast to conventional anti-CD4 monoclonal antibodies (mAbs), the humanized CD4-specific monoclonal antibody tregalizumab (BT-061) is able to selectively activate the suppressive properties of Tregs in vitro. BT-061 activates Tregs by binding to CD4 and activation of signaling downstream pathways. The specific functionality of BT-061 may be explained by the recognition of a unique, conformational epitope on domain 2 of th…