Generation of reference cell lines, media, and a process platform for CHO cell biomanufacturing.

Due to the favorable attributes of Chinese hamster ovary (CHO) cells for therapeutic proteins and antibodies biomanufacturing, companies generate proprietary cells with desirable phenotypes. One key attribute is the ability to stably express multi-gram per liter titers in chemically defined media. Cell, media, and feed diversity has limited community efforts to translate knowledge. Moreover, academic, and nonprofit researchers generally cannot study "industrially relevant" CHO cells due to limited public availability, and the time and knowledge required to generate such cells. To address these issues, a university-industrial consortium (Advanced Mammalian Biomanufacturing Innovation Center, AMBIC) has acquired two CHO "reference cell lines" from different lineages that express monoclonal antibodies. These reference cell lines have relevant production titers, key performance outcomes confirmed by multiple laboratories, and a detailed technology transfer protocol. In commercial media, titers over 2 g/L are reached. Fed-batch cultivation data from shake flask and scaled-down bioreactors is presented. Using productivity as the primary attribute, two academic sites aligned with tight reproducibility at each site. Further, a chemically defined media formulation was developed and evaluated in parallel to the commercial media. The goal of this work is to provide a universal, industrially relevant CHO culture platform to accelerate biomanufacturing innovation.

Transient ammonia stress on Chinese hamster ovary (CHO) cells yield alterations to alanine metabolism and IgG glycosylation profiles.

BACKGROUND: Ammonia concentrations typically increase during mammalian cell cultures, mainly due to glutamine and other amino acid consumption. An early ammonia stress indicator is a metabolic shift with respect to alanine. To determine the underlying mechanisms of this metabolic shift, a Chinese hamster ovary (CHO) cell line with two distinct ages (standard and young) was cultured in parallel fed-batch bioreactors with 0 mM or 10 mM ammonia added at 12 h. Reduced viable cell densities were observed for the stressed cells, while viability was not significantly affected. The stressed cultures had higher alanine, lactate, and glutamate accumulation. Interestingly, the ammonia concentrations were similar by Day 8.5 for all cultures. We hypothesized the ammonia was converted to alanine as a coping mechanism. Interestingly, no significant differences were observed for metabolite profiles due to cell age. Glycosylation analysis showed the ammonia stress reduced galactosylation, sialylation, and fucosylation. Transcriptome analysis of the standard-aged cultures indicated the ammonia stress had a limited impact on the transcriptome, where few of the significant changes were directly related metabolite or glycosylation reactions. These results indicate that mechanisms used to alleviate ammonia stress are most likely controlled post-transcriptionally, and this is where future research should focus.

Unruly grandmothers, ghosts and ancestors: Chinese elders and the importance of culture in dementia evaluations.

This article explores the cultural clashes that occurred when Chinese patients at an Alzheimer's center in California were evaluated for dementia. Lack of familiarity with Chinese culture made the culturally mainstream American clinicians at this center more likely to misinterpret the behavior of elderly Chinese-speaking patients and their families and, thereby, more likely to misdiagnose such patients and suggest culturally inappropriate recommendations. This tendency was reduced when relevant cultural knowledge was incorporated into the clinical evaluation. The evaluation process at this clinic and two patient examples are discussed to illustrate that familiarity with a patient's cultural background is essential for accurate diagnosis and referral. This ethnographic case study places the evaluation process in one particular clinic in cultural context and is suggestive in the way that exploratory qualitative research is meant to be, rather than broadly representative of dementia clinics or clinicians as a whole. However, problems created by cultural clashes at this clinic do suggest that what may be happening at other dementia clinics as they encounter increasingly more patients from diverse cultural backgrounds is an important empirical question worthy of further research, using both qualitative and quantitative methods.