Atezolizumab is an antibody inhibitor, a humanized monoclonal antibody, IgG1, which targets PD-L1 and blocks the interaction of PD-L1 with PD-1. Atezolizumab has antitumor activity and promotes T-cells to attack tumor cells.

METHODS: MDA-MB-231, BT-20, MDA-MB-468 cells and T cells were co-cultured and treated with Atezolizumab (50-100 µg/mL) for 4-24 h. T cell-mediated cytotoxicity assay was performed.
RESULTS: Atezolizumab significantly enhanced T cell-mediated cytotoxicity of MDA-MB-231 cells in a dose-dependent manner, with 100 µg/mL concentration of Atezolizumab showing significant efficacy at 4 and 24 h incubation.Similar results were obtained with BT-20. No Atezolizumab-induced T cell-mediated cytotoxicity was observed in PD-L1- MDA-MB-468 cells compared to MDA-MB-231 and BT-20 cells. [1]
METHODS: MDA-MB-231 cells were treated with Atezolizumab (0.5 µg/mL) for 24 h. Surface expression of PD-L1 was detected by flow cytometry.
RESULTS: Almost all MDA-MB-231 cells were positive for PD-L1, but the detection of PD-L1 epitopes was blocked by the specific antibody Atezolizumab after 24 h treatment. [2]

METHODS: To detect in vivo antitumor activity, Atezolizumab (10 mg/kg) and Bevacizumab (5 mg/kg) were intraperitoneally injected into BALB/C nude mice bearing A2780cis xenografts every two days for three weeks.
RESULTS: In vivo treatment with Atezolizumab or Bevacizumab induced significant antitumor effects and significantly inhibited tumor growth. Dual blockade with Atezolizumab and Bevacizumab significantly inhibited tumor growth compared to each treatment. [3]

Objective: Determine the binding of [111In]PD-L1-mAb to tumor cell lines. Cells: NCI-H2444（Lung Cancer cell line）, MDAMB231（Breast Cancer cell line）,etc. Concentrations: 1 μCi/100μl. Incubation Time: 1 h. Method: Incubating 1 μCi of [111In]PD-L1-mAb with 1×106cells (in triplicate for each cell line) for 1h at 37°C. PD-L1 blocking was performed by adding a 10-fold molar equivalent excess of the non-labeled mAb. After incubation, cells were washed three times with cold PBS prior to counting on an automated gamma counter.