Effects of Adalimumab, an Anti-tumour Necrosis Factor-Alpha (TNF-α) Antibody, on Obese Diabetic Rats

Increase recombinant antibody yields through optimizing vector design and production process in CHO cells

Chinese hamster ovary (CHO) cells are the most commonly used host cells for the production of recombinant monoclonal antibodies (mAbs) due to their several advantages. Although the yields of recombinant mAbs can be greatly increased by some strategies, such as medium formulation, culture conditions, and cell engineering, most studies focused on either upstream design or downstream processes. In the present study, we first expressed recombinant adalimumab through combination of the vector design and production process optimization in CHO cells. Bicistronic vector, monocistronic vector, and dual promoter vector were constructed, and the production process was optimized using low-temperature and fed-batch culture. The results showed that the dual promoter vector exhibited the highest yield under the transient and stable transfected cells among three different vector systems in CHO cells. In addition, low-temperature and fed-batch culture could further improve the yields of adalimumab. The purified antibody displayed tumor necrosis factor-α (TNF-α) binding activity. In conclusion, combination of expression vector design and production process optimization can achieve higher expression of recombinant mAbs in CHO cells. KEY POINTS: • The dual promoter vector is more effective for expressing recombinant antibodies. • The yields of antibodies are related to the LC chain expression level. • Low-temperature and feed addition can promote antibody production.

Effect of inflammatory bowel disease treatments on patients with diabetes mellitus

As medical care progresses and the number of patients with chronic conditions increases there is the inevitable challenge of managing patients with multiple co-morbidities. Inflammatory bowel disease (IBD) is an umbrella term for are inflammatory conditions affecting the gastrointestinal tract, the two most common forms being Ulcerative Colitis and Crohn’s disease. These diseases, usually diagnosed in young adults, exhibit a relapsing and remitting course and usually require long-term treatment. IBD can be treated with a number of topical and systemic treatments. We conducted a review of the current published evidence for the effects these medications can have on diabetes mellitus (DM) and glycaemic control. Searches were conducted on medline and embase with a timeframe from 1947 (the date from which studies on embase are recorded) to November 2020. Suitable publications were selected and reviewed. Current evidence of the impact of aminosalicylates, corticosteroids, thiopurines, and biologic agents was reviewed. Though there was limited evidence for certain agents, IBD medications have been shown to have an effect of DM and these effects should be considered in managing patients with dual pathologies. The effects of steroids on blood sugar control is well documented, but consideration of other agents is also important. In patients requiring steroids for Ulcerative Colitis, locally acting steroid agents delivered rectally may be preferred to minimise side effects in those with distal bowel Ulcerative Colitis. A switch to other agents should be considered as soon as possible in people with diabetes to limit the impact on glycaemic control. 5-aminosalicylates appear to play a role in the reduction of hemoglobin A1c (HbA1c), although the literature suggests these may be falsely low readings. Consequently, monitoring of people with diabetes on these agents may require daily monitoring of capillary blood sugars rather than relying simply on HbA1c; for example fructosamine performed 3-6 monthly, although this risks missing the rise in readings. There is only limited evidence of the effects of thiopurines on diabetes and further investigation is needed into the possible relationship between them. However, given the current available evidence it may be preferable to commence patients with diabetes on thiopurines as soon as possible, whilst also monitoring for side effects such as pancreatitis. There appears to be more evidence supporting a link between tumor necrosis factor-α inhibitors and DM. Both infliximab and adalimumab have evidence suggesting that both can cause reduced blood sugar levels. Further studies on the effects of the various biological agents mentioned are required alongside any novel biologic therapy and the impact of dual biologic therapy in the future.

TNF-alpha inhibitor adalimumab attenuates endotoxin induced cardiac damage in rats

Purpose

To investigate the effects of adalimumab pretreatment on the lipopolysaccharide-mediated myocardial injury.

Methods

Twenty-eight Wistar rats were randomized into four groups (n=7). Control (C) group animals were injected once a day with intraperitoneal (i.p) 0.9 % saline for two days. In the Adalimumab (Ada) group, adalimumab was injected at a dose of 10 mg/kg/ day (i.p) for two days. Lipopolysaccharide (Lps) group rats were injected with a dose of 5 mg/kg (i.p) lipopolysaccharide. Lipopolysaccharide + Adalimumab (Lps+Ada) group rats received adalimumab before the administration of lipopolysaccharide. The animals were sacrificed 24 h after the last injection and blood samples were obtained for determination of biochemical cardiac injury markers and circulating levels of TNF-α and interleukin-6 (IL-6). Hearts were harvested for histological examination.

Results

Endotoxin exposure resulted in significant increases in serum cardiac injury markers, serum cytokines and histological myocardial injury scores in the Lps group. The levels of circulating cytokines, cardiac injury markers and histological injury scores for myocardial necrosis, perivascular cell infiltration, and inflammation were significantly reduced in Lps+Ada as compared to Lps group (p<0.05).

Conclusions

Adalimumab pretreatment reduces endotoxin-induced myocardial damage in rats. This beneficial effect is thought to be related to the reduction of cytokine release.