scholarly journals Intracellular Phospho-Flow cytometry reveals novel insights into TCR proximal signaling events. A comparison with Western blot

2008 ◽  
Vol 73A (9) ◽  
pp. 799-807 ◽  
Author(s):  
Anna Haas ◽  
Gisbert Weckbecker ◽  
Karl Welzenbach
2022 ◽  
Vol 2022 ◽  
pp. 1-11
Author(s):  
Xian Zhang ◽  
Jiajia Ge ◽  
Xuejuan Zhu ◽  
Haifeng Zhang ◽  
Yuanzi Wang ◽  
...  

The aim of the present study was to investigate the effects and mechanism of oxymatrine (OMT) combined with compound yinchen granules (CYG) on the apoptosis of hepatocytes through the Akt/FoxO3a/Bim pathway in rats with acute liver failure. The rat model of acute liver failure was established using lipopolysaccharide/D-galactosamine (LPS/D-GalN). The expression of proteins in rat liver tissues was detected by western blot analysis. The mRNA expression of FoxO3a, Bim, Bax, Bcl-2, and caspase-3 in rat liver tissues was detected by RT-qPCR. The apoptosis rate of rat hepatocytes was determined by flow cytometry. Western blots showed that when compared with the normal group, the expression of p-Akt and p-FoxO3a in the model group was decreased ( P < 0.05 ), while the expression of Bim was increased ( P < 0.01 ). Compared with the model group, the expression of p-Akt and p-FoxO3a in the OMT group and the OMT combined with CYG groups was increased ( P < 0.05 or P < 0.01 ), while the expression of Bim was decreased ( P < 0.05 ). The Bax/Bcl-2 ratio and caspase-3 protein expression in the model group were significantly higher than those in the normal group ( P < 0.01 ). The Bax/Bcl-2 ratio and the expression of caspase-3 protein in the OMT group and the OMT combined with CYG groups were significantly lower than those in the model group ( P < 0.01 ). The results of RT-qPCR were consistent with those of western blot. The results of flow cytometry showed that the apoptosis rate of hepatocytes in the OMT group and the OMT combined with CYG groups was significantly lower than that in the model group ( P < 0.05 or P < 0.01 ). We concluded that LPS/D-GalN can induce apoptosis of hepatocytes in rats with acute liver failure through the Akt/FoxO3a/Bim pathway. OMT combined with CYG inhibits apoptosis of hepatocytes in rats with acute liver failure via the Akt/FoxO3a/Bim pathway.


2020 ◽  
Author(s):  
Wenyu Jia ◽  
Siwan Luo ◽  
Gena Lai ◽  
Shiqi Li ◽  
Shuai Huo ◽  
...  

Abstract BackgroundPolyporus polysaccharide (PPS), an active ingredient of traditional Chinese medicinal Polyporus umbellatus, has multiple biological functions, such as anti-cancer, immune-regulating and hepatoprotective activities. The purpose of this study was to investigate the mechanism of PPS activated macrophages in the treatment of bladder cancer.Methods100 ng/mL Phorbol myristate acetate (PMA) was used to induce THP-1 human leukemic cells as a macrophage model. Flow cytometry was used to detect the expression of CD14 and CD68 to verify the establishment of macrophage model. After that, Macrophages derived from THP-1 were treated with different concentrations of PPS (1,10 and 100 ug/mL). Flow cytometry and RT-PCR were used to detected the expression of CD16, CD23, CD86, CD40 and interleukin (IL)-Iβ, iNOS mRNA. ELISA was used to test the change of IL-1β and TNF-α in macrophage after the treatment with PPS. The conditioned medium from PPS-polarized macrophages was used to detect the effect of activated macrophages on bladder cancer. MTT assay, 5-ethynyl-2¢-deoxyuridine assay, flow cytometry, Transwell assay, and Western blot analysis were used to detect the effects of polarized macrophages on the viability, proliferation, apoptosis, and migration of bladder cancer cells. Western blot was also used to analysis the change of JAK2/NF-κB pathway protein.ResultsPPS promoted the expression of pro-inflammatory factors, such as IL-Iβ, TNF-α and iNOS, and surface molecules CD86, CD16, CD23, and CD40 in macrophages and then polarized macrophages to M1 type. The results demonstrated that activated macrophages inhibited the proliferation of bladder cancer cells, regulated their apoptosis, and inhibited migration and epithelial–mesenchymal transformation (EMT). JAK2/NF-κB pathways were downregulated in the anti-bladder cancer process of activated macrophages. ConclusionThe findings indicated that PPS inhibited the proliferation and progression of bladder cancer by the polarization of macrophages to M1 type, and JAK2/NF-κB pathway was downregulated in the process of anti-bladder cancer.


PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0246197
Author(s):  
Jorge Marquez ◽  
Jianping Dong ◽  
Chun Dong ◽  
Changsheng Tian ◽  
Ginette Serrero

Antibody-drug conjugates (ADC) are effective antibody-based therapeutics for hematopoietic and lymphoid tumors. However, there is need to identify new targets for ADCs, particularly for solid tumors and cancers with unmet needs. From a hybridoma library developed against cancer cells, we selected the mouse monoclonal antibody 33B7, which was able to bind to, and internalize, cancer cell lines. This antibody was used for identification of the target by immunoprecipitation and mass spectrometric analysis, followed by target validation. After target validation, 33B7 binding and target positivity were tested by flow cytometry and western blot analysis in several cancer cell lines. The ability of 33B7 conjugated to saporin to inhibit in vitro proliferation of PTFRN positive cell lines was investigated, as well as the 33B7 ADC in vivo effect on tumor growth in athymic mice. All flow cytometry and in vitro internalization assays were analyzed for statistical significance using a Welsh’s T-test. Animal studies were analyzed using Two-Way Analysis of Variance (ANOVA) utilizing post-hoc Bonferroni analysis, and/or Mixed Effects analysis. The 33B7 cell surface target was identified as Prostaglandin F2 Receptor Negative Regulator (PTGFRN), a transmembrane protein in the Tetraspanin family. This target was confirmed by showing that PTGFRN-expressing cells bound and internalized 33B7, compared to PTGFRN negative cells. Cells able to bind 33B7 were PTGFRN-positive by Western blot analysis. In vitro treatment PTGFRN-positive cancer cell lines with the 33B7-saporin ADC inhibited their proliferation in a dose-dependent fashion. 33B7 conjugated to saporin was also able to block tumor growth in vivo in mouse xenografts when compared to a control ADC. These findings show that screening antibody libraries for internalizing antibodies in cancer cell lines is a good approach to identify new cancer targets for ADC development. These results suggest PTGFRN is a possible therapeutic target via antibody-based approach for certain cancers.


Author(s):  
Mingliang Ma ◽  
Huan Qi ◽  
Chuansheng Hu ◽  
Zhaowei Xu ◽  
Fanlin Wu ◽  
...  

Abstract PD-1 plays an important role as an immune checkpoint. Sintilimab is a newly approved PD-1 antibody for cancer immunotherapy with an unknown binding epitope on PD-1. In this study, to elucidate the molecular mechanism by which sintilimab blocks PD-1 activation, we applied Antibody binding epitope Mapping (AbMap) to identify the binding epitope of sintilimab. An epitope was successfully identified, i.e. SLAPKA, aa 127–132. By constructing a series of point mutations, the dominant residues S127, L128, A129, P130, and A132 of PD-1 were further validated by western blot analysis, biolayer interferometry, and flow cytometry. Structural analysis showed that the epitope is partially within the binding interface of PD-1 and PD-L1, and this epitope also partially overlaps with that of nivolumab and pembrolizumab. These results demonstrate that sintilimab can attenuate PD-1 activation by directly competing with the interaction between PD-1 and PD-L1 through binding with the key residues of the FG loop on PD-1. This study also demonstrates the high efficiency and accuracy of AbMap for determining the binding epitope of therapeutic antibodies.


Antibodies ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 37 ◽  
Author(s):  
Jennifer Linden ◽  
Kiel Telesford ◽  
Samantha Shetty ◽  
Paige Winokour ◽  
Sylvia Haigh ◽  
...  

The pore-forming epsilon toxin (ETX) produced by Clostridium perfringens is among the most lethal bacterial toxins known. Sensitive antibody-based reagents are needed to detect toxin, distinguish mechanisms of cell death, and prevent ETX toxicity. Using B-cell immuno-panning and cloning techniques, seven ETX-specific monoclonal antibodies were generated from immunized rabbits. ETX specificity and sensitivity were evaluated via western blot, ELISA, immunocytochemistry (ICC), and flow cytometry. ETX-neutralizing function was evaluated both in vitro and in vivo. All antibodies recognized both purified ETX and epsilon protoxin via western blot with two capable of detecting the ETX-oligomer complex. Four antibodies detected ETX via ELISA and three detected ETX bound to cells via ICC or flow cytometry. Several antibodies prevented ETX-induced cell death by either preventing ETX binding or by blocking ETX oligomerization. Antibodies that blocked ETX oligomerization inhibited ETX endocytosis and cellular vacuolation. Importantly, one of the oligomerization-blocking antibodies was able to protect against ETX-induced death post-ETX exposure in vitro and in vivo. Here we describe the production of a panel of rabbit monoclonal anti-ETX antibodies and their use in various biological assays. Antibodies possessing differential specificity to ETX in particular conformations will aid in the mechanistic studies of ETX cytotoxicity, while those with ETX-neutralizing function may be useful in preventing ETX-mediated mortality.


2018 ◽  
Vol 49 (6) ◽  
pp. 2151-2162 ◽  
Author(s):  
Bo Lian ◽  
Dongxiang Yang ◽  
Yanlong Liu ◽  
Gang Shi ◽  
Jibin Li ◽  
...  

Background/Aims: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an ideal anti-tumor drug because it exhibits selective cytotoxicity against cancer cells. However, certain cancer cells are resistant to TRAIL, and the potential mechanisms are still unclear. The aim of this study was to reduce the resistance of colorectal cancer (CRC) cells to TRAIL. Methods: Quantitative real-time PCR analysis was performed to detect the expression of microRNA-128 (miR-128) in tissues from patients with CRC and CRC cell lines. MTT assays were used to evaluate the effect of miR-128 on TRAIL-induced cytotoxicity against CRC cell lines. The distribution of death receptor 5 (DR5) and the production of reactive oxygen species (ROS) were detected by flow cytometry analysis. Western blot, flow cytometry, and luciferase reporter assays were performed to evaluate the potential mechanism and pathway of miR-128-promoted apoptosis in TRAIL-treated CRC cells. Results: MiR-128 expression was downregulated in tumor tissues from patients with CRC as well as in CRC cell lines in vitro. The enforced expression of miR-128 sensitized CRC cells to TRAIL-induced cytotoxicity by inducing apoptosis. Mechanistically, bioinformatics, western blot analysis, and luciferase reporter assays showed that miR-128 directly targeted sirtuin 1 (SIRT1) in CRC cells. miR-128 overexpression suppressed SIRT1 expression, which promoted the production of ROS in TRAIL-treated CRC cells. This increase of ROS subsequently induced DR5 expression, and thus increased TRAIL-induced apoptosis in CRC cells. Conclusion: The combination of miR-128 with TRAIL may represent a novel approach for the treatment of CRC.


2019 ◽  
Vol 33 ◽  
pp. 205873841982889
Author(s):  
Jiajing Luo ◽  
Yi Chen ◽  
Chengjia Ding ◽  
Jialing Qiu ◽  
Yulan Chen ◽  
...  

The purpose of this study was to focus on the underlying relationship between the hyperactivity for the peripheral monocytes and heat stroke by investigating the inflammatory oxidative activity of and the expression of superficial molecules. Peripheral blood samples were collected from 10 healthy adult volunteers. Human blood monocytes were isolated by density gradient centrifugation and sequent adherent culture. The objectives were divided into four groups: 43°C heat stress combined with lipopolysaccharide (LPS) group, 43°C heat stress group, LPS group, and control group. There were 10 cases in each group. An enzyme-linked immunosorbent assay (ELISA) test was used to measure the concentrations of supernatant inflammatory mediators (tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β) and interleukin-10 (IL-10)). After loaded by 2,7-Dichlorodi-hydrofluorescein-diacetate (DCFHDA) fluorescent probe, intracellular reactive oxygen species (ROS) levels were determined by a flow cytometry. After fluorescent microspheres incubation, the phagocytosis of monocytes was observed under a fluorescent microscope. Respectively, the flow cytometry and Western blot were used to evaluate the level of triggering receptor expressed on myeloid cells-1 (TREM-1) and Toll-like receptor-4 (TLR-4) on the monocytes. Furthermore, the mRNA expression of TREM-1 and TLR-4 was detected by real-time polymerase chain reaction (RT-PCR). The heat stress combined with LPS stimulation promoted the peripheral monocytes to produce inflammatory mediators (TNF-α, IL-1β, and IL-10) and release ROS. Otherwise, such complex strike significantly suppressed the phagocytic activity of monocytes in peripheral blood. Moreover, the expression of TREM-1, TLR-4 and CD86 was measured by the flow cytometry on peripheral monocytes which were respectively promoted by the union of heat stress and LPS. The results of Western blot and RT-PCR demonstrated the similar kinetics on these superficial molecules (TREM-1, TLR-4, and CD86) stimulated by the combination of heat stress and LPS. The underlying mechanism of the dysfunction for the peripheral monocytes may be related to the abnormal expression of superficial molecules TREM-1, TLR-4, and CD86 on the monocytes induced by heat stress and LPS.


Sign in / Sign up

Export Citation Format

Share Document