85 research outputs found
Process Development for Efficient Production of Antibodies with High Antibody-Dependent Cellular Cytotoxicity Activity from a YB2/0 Cell Line
The contribution of biopharmaceutical industries to general healthcare is rapidly increasing
with over 165 products having been approved globally since 1982. Within the therapeutic
applications of biopharmaceuticals, monoclonal antibodies (MAbs) are of growing interest.
Recently, more than twenty therapeutic MAbs and related proteins have been launched in the
market. This situation is a double-edged sword because it leads to pressure on pharmaceutical
economy. Minimizing the cost of goods (COGS) and maximizing antibody activity are therefore
active areas of research in the development of MAbs for therapeutic use.
We have screened several enhancers of specific MAb production rate (SPR) using the rat
hybridoma YB2/0 cell line and found that coenzyme-Q10 (CoQ10) is a promising enhancer
candidate. CoQ10 is well known as a strong antioxidant in the respiratory chain and is used for
healthcare and other applications. Because CoQ10 is negligibly water soluble, most studies are
limited by low concentrations. We added CoQ10 to a culture media using dispersion of
nano-particles (Q-Media) at several concentrations and conducted a fed-batch culture. Although
the Q-Media had no effect on cumulative viable cell density, it enhanced the SPR by 66%. In
addition, the Q-Media had no effect on the binding or cytotoxic activity of MAbs. Q-Media also
enhanced SPR with CHO and NS0 cell lines by 30%. On the other hand, the Q-Media did not
alter the concentration of the oxidative stress marker 8-hydroxy-2'-deoxyguanosine in the culture
supernatant. Furthermore, Q-Media decreased the ratio of lactate production to glucose
consumption only slightly, and CoQ10 (232 μM) elevated intracellular Ca2+ concentration, as did
ATP (10 μM). These observations suggest that CoQ10 serves as a powerful aid in the production
of MAbs by enhancing SPR without changing the character of cell growth, or adversely affecting
quality or biological activity of MAbs.
Antibody-dependent cellular cytotoxicity (ADCC) is dependent on the fucose content of
oligosaccharides bound to MAbs. As MAbs with a low fucose content exhibit high ADCC
activity, it is important to control the defucosylation levels (deFuc%) of MAbs and to analyze the
factors that affect deFuc%. In this study, we observed that the deFuc% was inversely related to
culture medium osmolality for the MAbs produced in the YB2/0 cell line, with the r2 value as
high as 0.92. Moreover, deFuc% exhibited the same correlation irrespective of the type of
compound used for regulating osmolality (NaCl, KCl, fucose, fructose, creatine, or mannitol) or
culture scale (1–400 L). We succeeded in controlling MAb deFuc% by maintaining a constant
medium osmolality constant in both perfusion and fed-batch cultures. The regulation of medium
osmolality with glucose is, however, sufficient for designing the deFuc% desired for efficacious
ADCC in YB2/0 cell culture. In agreement with these observations, real-time PCR analyses
revealed decreased transcription of genes involved in the glycolysis, GDP-fucose supply, and
fucose transfer.
In this sutudy, both methods to enhance the efficiency of the production are achieved as an
extension to existing processes. The present method to control deFuc% with medium osmolality
will open the way to use those mammalian cells, for glycoprotein production, that could not be
employed because of unwantedly high and/or uncontrollable fucose content in the
oligosaccharides attached to the protein. These findings will enable the use of the defucosylated
IgG1 at lower doses with no reduction in efficacy without restart such as chainging the cell bank.学位記番号:工博甲42
Cell-Based Sensor System Using L6 Cells for Broad Band Continuous Pollutant Monitoring in Aquatic Environments
Pollution of drinking water sources represents a continuously emerging problem in global environmental protection. Novel techniques for real-time monitoring of water quality, capable of the detection of unanticipated toxic and bioactive substances, are urgently needed. In this study, the applicability of a cell-based sensor system using selected eukaryotic cell lines for the detection of aquatic pollutants is shown. Readout parameters of the cells were the acidification (metabolism), oxygen consumption (respiration) and impedance (morphology) of the cells. A variety of potential cytotoxic classes of substances (heavy metals, pharmaceuticals, neurotoxins, waste water) was tested with monolayers of L6 cells (rat myoblasts). The cytotoxicity or cellular effects induced by inorganic ions (Ni2+ and Cu2+) can be detected with the metabolic parameters acidification and respiration down to 0.5 mg/L, whereas the detection limit for other substances like nicotine and acetaminophen are rather high, in the range of 0.1 mg/L and 100 mg/L. In a close to application model a real waste water sample shows detectable signals, indicating the existence of cytotoxic substances. The results support the paradigm change from single substance detection to the monitoring of overall toxicity
Erratum: The Belle II Physics Book (Progress of Theoretical and Experimental Physics (2019) 2019 (123C01) DOI: 10.1093/ptep/ptz106)
Measurements of the branching fractions for decays at Belle II
This paper reports a study of decays using
fb of data collected during 2019--2020 by the Belle II experiment at the
SuperKEKB asymmetric-energy collider, corresponding to events. We find , ,
, and signal events in the decay modes , ,
, and , respectively. The uncertainties quoted for the
signal yield are statistical only. We report the branching fractions of these
decays: where the first
uncertainty is statistical, and the second is systematic. The results are
consistent with world-average values
The Belle II Physics Book
We present the physics program of the Belle II experiment, located on the
intensity frontier SuperKEKB collider. Belle II collected its first
collisions in 2018, and is expected to operate for the next decade. It is
anticipated to collect 50/ab of collision data over its lifetime. This book is
the outcome of a joint effort of Belle II collaborators and theorists through
the Belle II theory interface platform (B2TiP), an effort that commenced in
2014. The aim of B2TiP was to elucidate the potential impacts of the Belle II
program, which includes a wide scope of physics topics: B physics, charm, tau,
quarkonium, electroweak precision measurements and dark sector searches. It is
composed of nine working groups (WGs), which are coordinated by teams of
theorist and experimentalists conveners: Semileptonic and leptonic B decays,
Radiative and Electroweak penguins, phi_1 and phi_2 (time-dependent CP
violation) measurements, phi_3 measurements, Charmless hadronic B decay, Charm,
Quarkonium(like), tau and low-multiplicity processes, new physics and global
fit analyses. This book highlights "golden- and silver-channels", i.e. those
that would have the highest potential impact in the field. Theorists
scrutinised the role of those measurements and estimated the respective
theoretical uncertainties, achievable now as well as prospects for the future.
Experimentalists investigated the expected improvements with the large dataset
expected from Belle II, taking into account improved performance from the
upgraded detector.Comment: 689 page
Angular analysis of decays reconstructed in 2019, 2020, and 2021 Belle II data
We report on a Belle II measurement of the branching fraction
(), longitudinal polarization fraction (), and CP asymmetry
() of decays. We reconstruct decays in a
sample of SuperKEKB electron-positron collisions collected by the Belle II
experiment in 2019, 2020, and 2021 at the (4S) resonance and
corresponding to 190 fb of integrated luminosity. We fit the
distributions of the difference between expected and observed candidate
energy, continuum-suppression discriminant, dipion masses, and decay angles of
the selected samples, to determine a signal yield of events. The
signal yields are corrected for efficiencies determined from simulation and
control data samples to obtain $\mathcal{B}(B^+ \to \rho^+\rho^0) = [23.2^{+\
2.2}_{-\ 2.1} (\rm stat) \pm 2.7 (\rm syst)]\times 10^{-6}f_L = 0.943 ^{+\
0.035}_{-\ 0.033} (\rm stat)\pm 0.027(\rm syst)\mathcal{A}_{CP}=-0.069
\pm 0.068(\rm stat) \pm 0.060 (\rm syst)\mathcal{A}_{CP}B^+\to
\rho^+\rho^0$ decays reported by Belle II
Determination of from untagged decays using 2019-2021 Belle II data
We present an analysis of the charmless semileptonic decay , where , from 198.0 million pairs of
mesons recorded by the Belle II detector at the SuperKEKB
electron-positron collider. The decay is reconstructed without identifying the
partner meson. The partial branching fractions are measured independently
for and as functions of
(momentum transfer squared), using 3896 and
5466 decays. The total branching fraction is
found to be for decays, where the uncertainties are statistical and
systematic, respectively. By fitting the measured partial branching fractions
as functions of , together with constraints on the nonperturbative
hadronic contribution from lattice QCD calculations, the magnitude of the
Cabibbo-Kobayashi-Maskawa matrix element , , is extracted. Here, the first uncertainty is
statistical, the second is systematic and the third is theoretical
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