China
Africa
Explore chapters and articles related to this topic
Combined Purging Approaches in Autologous Transplantation
Published in Adrian P. Gee, BONE MARROW PROCESSING and PURGING, 2020
Elizabeth J. Shpall, Robert C. Bast, Charles S. Johnston, William P. Peters, Roy B. Jones
The purification of the antibodies was carried out using five single-use protein A columns. Twelve milliliters of Protein-A Sepharose (Pharmacia LKB, Uppsala, Sweden) was packed in a 1.5 × 20 cm column (Bio-Rad Laboratories, Richmond, CA). The column was washed three times with 25 ml of sterile sodium citrate buffer (pH 3.0) and then neutralized by washing three times with 25 ml of sterile sodium phosphate buffer (pH 8.0).
Immune Modulation In Sepsis
Published in Thomas F. Kresina, Immune Modulating Agents, 2020
Janet M. J. Hammond, Peter D. Potgieter
In order to study the toxicological and pharmacological characteristics of the bactericidal/permeability-increasing protein, the same group performed a further prospective randomized, placebo-controlled laboratory study to assess the pharmacokinetics of intravenously injected bactericidal/permeability-increasing protein in mice [170]. They found this substance to be a potent antiendotoxin, which was able to neutralize endotoxin in vivo and prevent mortality in animal models from lethal endotoxemia (mortality rate of 6.25% in mice receiving bactericidal/permeability-increasing protein compared with 100% in those receiving saline, p = 0.001). In addition, no alterations in hematological, renal, or hepatic function; activity level; or weight gain were observed over a 7-day study period. The LD50 was increased up to 32-fold by the simultaneous administration of bactericidal/permeability-increasing protein at 10 mg/kg. A dose-response effect was evident in the endotoxin-challenge experiments, indicating that the level of protection provided by the protein was directly proportional to the circulating concentrations of the molecule.
Immunohistochemistry of the Pulmonary Extracellular Matrix
Published in Joan Gil, Models of Lung Disease, 2020
Antonio Martinez-Hernandez, Peter S. Amenta
Immunoglobulins can bind to tissues through several nonimmune mechanisms, such as Fc-binding and nonspecific protein-protein interactions. To minimize this nonimmune binding, treatment of the sections with preimmune serum, from the animal species providing the secondary antibody, is used. Of course, using Fab fragments rather than complete IgG molecules will prevent binding to Fc receptors (Martinez-Hernandez, 1987a,b; Amenta and Martinez-Hernandez, 1987).
Insights into ultra-low affinity lipase-antibody noncovalent complex binding mechanisms
Published in mAbs, 2022
Elizabeth Sara Hecht, Shrenik Mehta, Aaron T. Wecksler, Ben Aguilar, Nathaniel Swanson, Wilson Phung, Ananya Dubey Kelsoe, W. Henry Benner, Devin Tesar, Robert F. Kelley, Wendy Sandoval, Alavattam Sreedhara
Were lipase antibody complexes to form on-column, during drug purification, the F(ab’)2 domains would be the most solvent-accessible region for lipase binding. Protein A binding of antibodies is known to occur in the Fc portion of the antibody, between the CH2 and CH3 domains.45 The importance of antibody orientation on the beads in a chromatography column is supported in a study examining the impact of antibody load on protein A column, where it was shown that PLBL2 elution increased at a disproportionately greater rate to antibody load.46 The authors proposed that an increasing number of interaction sites on a column could be responsible, and the work reported here specifically suggests that the F(ab’)2 domain orientation could be a critical parameter. Interestingly, the CH1 region highlighted in this study neighbors a region implicated in PLBL2 binding to mAbs, as determined by SPR, and reported in a 2018 patent,47 but this region did not appear as a common site across the mAbs that were tested in this study. Possible differences include buffer composition used in each study or structural differences in the expressed lipases. While our data suggest that there is a common lipase/esterase binding site on the CH1 domain of IgGs, a thorough phylogenetic assessment of lipases/hydrolases is essential to make such a generic claim. Such an analysis is out of scope for this study but could be an interesting exercise for the future.
Human umbilical cord-mesenchymal stem cells conditioned medium attenuates CCl4 induced chronic liver fibrosis
Published in Toxin Reviews, 2021
Alireza Pouyandeh Ravan, Farjam Goudarzi, Hassan Rafieemehr, Mahdi Bahmani, Fariba Rad, Mohammad Jafari, Marzieh Mahmoodi
The UC - MSCs (fourth passage) were washed with PBS until they attained 70–80% confluence. After that, they were preincubated with serum-free fresh RPMI-1640 enriched with 0.5% bovine serum albumin (Sigma-Aldrich). The incubation was done for 72 h at 37 °C in a humidified atmosphere in the presence of 5% CO2. When the confluence of the cells reached 90% and had a survival percentage of >99% (Obtained by trypan blue staining), their conditioned medium was collected. After collecting, they were concentrated by several centrifugation steps; 400 × g for 10 min and 15,000 × g for another 10 min. The final supernatant of each tube (10 ml) was collected and placed into a freezer-dryer chamber according to the manufacturer's instructions. The lyophilized samples (350 mg from each 10 ml supernatant) were frozen at –80 °C for future use. The protein level of the conditioned medium was analyzed by BCA assay kit (Kiazist Life Sciences, Iran) and three doses of 400, 200, and 100 µg protein/kg body weight in 100 µl PBS were tested for the preparative experiment. After analyzing the side effects of different doses, finally, according to histopathological and biochemical observations, 100 µg protein/kg dosage was selected (As supplementary data).
Optimization and kinetic modeling of interchain disulfide bond reoxidation of monoclonal antibodies in bioprocesses
Published in mAbs, 2020
Peifeng Tang, Zhijun Tan, Vivekh Ehamparanathan, Tingwei Ren, Laurel Hoffman, Cheng Du, Yuanli Song, Li Tao, Angela Lewandowski, Sanchayita Ghose, Zheng Jian Li, Shijie Liu
A distinctive aspect of this study was our examination of the kinetics of disulfide formation on the Protein A resin. Here, we selected Protein A chromatography as the unit operation to implement the rescue strategy based on the following three factors. First, the affinity between mAb and Protein A ligand is through Fc region of the antibody. Since the high-order structure is intact, the affinity between mAb and Protein A would remain unchanged. Thus, reduced mAb still binds to Protein A resin. As our dynamic binding capacity study (Tan et al, mAbs, in press) showed, at 10% breakthrough and 4-min residence time, mAb material containing three different LMW levels (90%, 50%, and 1%) achieved DBCs of 58.6, 58.6, and 58.5 g/Lresin, respectively. Second, Protein A chromatography is a general unit operation to purify mAb, and implementing the rescue strategy in Protein A chromatography could be a mAb platform process operation.51,52 Third, compared with ion-exchange chromatography, Protein A chromatography is less sensitive to operation buffer composition change and easier to include the redox pair into Protein A chromatography operation buffer.53