Development of serum-free medium supplemented with hydrolysates for the production of therapeutic antibodies in CHO cell cultures using design of experiments

An efficient method of formulating serum-free medium (SFM) for production of therapeutic antibodies by recombinant CHO (rCHO) cells was developed using two rCHO cell lines producing a therapeutic antibody. In this method, ten kinds of SFM were prepared by supplementing the basal SFM with statistically designed mixtures (total 5 g L^?1) of three non-animal-derived hydrolysates: yeastolate, soy hydrolysate, and wheat gluten hydrolysate. When the two rCHO cell lines were cultivated, the mixtures of soy hydrolysate and wheat gluten hydrolysate showed a positive effect on cell growth. On the other hand, the mixtures including a high portion of yeastolate significantly enhanced specific antibody productivity. To reconstitute the mixture ratios of the three hydrolysates for high growth and antibody production, the effect of each medium was analyzed by the statistical program Design-Expert®. The resulting medium gave a 1.9–3.3-fold increase in the maximum antibody concentration, compared to the basal SFM. Taken together, the supplementation of hydrolysates to the basal SFM with the help of statistical analysis is an efficient means of developing SFM for therapeutic antibody production by rCHO cells.     

一种复合益生菌粉增强免疫力功能的动物研究

通过细胞免疫、体液免疫、单核巨噬细胞吞噬功能、NK细胞活性测定试验检验由植物乳植杆菌HEAL9和副干酪乳酪杆菌8700:2配制而成的复合益生菌粉对小鼠免疫力功能的影响。

将50只雄性BALB/c小鼠按体质量随机分为阴性对照组、阳性对照组以及益生菌粉低、中和高剂量组,每组10只,分别使用去离子水、转移因子口服液和相应浓度的益生菌粉进行灌胃给药,1次/d,连续30 d。实验过程中分别对小鼠进行迟发型变态反应试验、抗体生成细胞检测及血清溶血素生成试验。末次给药次日,对小鼠进行淋巴细胞转化的影响试验、碳廓清试验和腹腔巨噬细胞吞噬鸡红细胞试验。并委托细胞室进行靶细胞（YAC-1）传代,进行NK细胞活性试验。

与阴性对照组相比,益生菌粉低、中、高剂量组小鼠脾淋巴细胞增殖能力、抗体积数及NK细胞活性均升高,益生菌粉高剂量组小鼠耳肿胀度、溶血空斑数、吞噬指数及吞噬百分率升高,差异均有统计学意义（P＜0.05或P＜0.01）。

依照《保健食品功能评价方法（2020年版）（征求意见稿）》有助于增强免疫力功能检验方法及结果判定,判定该复合益生菌粉具有增强免疫力功能作用。

     

Yeast hydrolysate as a low-cost additive to serum-free medium for the production of human thrombopoietin in suspension cultures of Chinese hamster ovary cells

To enhance the performance of a serum-free medium (SFM) for human thrombopoietin (hTPO) production in suspension cultures of recombinant Chinese hamster ovary (rCHO) cells, several low-cost hydrolysates such as yeast hydrolysate (YH), soy hydrolysate, wheat gluten hydrolysate and rice hydrolysate were tested as medium additives. Among various hydrolysates tested, the positive effect of YH on hTPO production was most significant. When 5 g l^–1 YH was added to SFM, the maximum hTPO concentration in batch culture was 40.41 g ml^–1, which is 11.5 times higher than that in SFM without YH supplementation. This enhanced hTPO production in YH-supplemented SFM was obtained by the combined effect of enhanced q_hTPO (the specific rate of hTPO production). The supplementation of YH in SFM increased q_hTPO by 294% and extended culture longevity by >2 days if the culture was terminated at a cell viability of 50%. Furthermore, cell viability throughout the culture using YH-supplemented SFM was higher than that using any other hydrolysate-supplemented SFM tested, thereby minimizing degradation of hTPO susceptible to proteolytic degradation. In addition, YH supplementation did not affect in vivo biological activity of hTPO. Taken together, the results obtained demonstrate the potential of YH as a medium additive for hTPO production in serum-free suspension cultures of rCHO cells.     

Spontaneous cell-mediated cytolysis by peripheral blood cells obtained from whole-body chronically irradiated beagle dogs

The level of natural killer (NK) activity of continuously gamma-irradiated (whole body) beagle dogs and their nonirradiated controls was studied. For analytical purposes, irradiated dogs were segregated into groups according to their clinical status: clinically normal, hypocellular, or with acute non-lymphocytic leukemia. Since unirradiated control animals exhibited a wide range of NK responses, the data from each irradiated animal were compared to its own age-matched or litter-matched unirradiated control. Of the eight clinically normal irradiated dogs (median = 146% activity of control) only one animal had a NK activity lower than that of its control. The hypocellular group (n = 5, median = 21.8% of control) and the leukemic group (n = 4, median = 52.5% of control) each contained one responder with higher activity than its control. The difference between the percentage of control of the clinically normal and clinically abnormal dogs was found to be significant (P less than 0.05). There is a negative correlation between the NK results obtained and the total accumulated dose of radiation at the time of sampling (correlation coefficient = -0.739, P less than 0.01), suggesting a radiation effect upon natural killer activity, which is evidence by enhancement at lower doses and depression at higher doses of irradiation.     

Production of a novel wheat gluten hydrolysate containing dipeptidyl peptidase-IV inhibitory tripeptides using ginger protease

Wheat gluten is a Pro-rich protein complex comprising glutenins and gliadins. Previous studies have reported that oral intake of enzymatic hydrolysates of gluten has beneficial effects, such as suppression of muscle injury and improvement of hepatitis. Here, we utilized ginger protease that preferentially cleaves peptide bonds with Pro at the P₂ position to produce a novel type of wheat gluten hydrolysate. Ginger protease efficiently hydrolyzed gluten, particularly under weak acidic conditions, to peptides with an average molecular weight of <600 Da. In addition, the gluten hydrolysate contained substantial amounts of tripeptides, including Gln-Pro-Gln, Gln-Pro-Gly, Gln-Pro-Phe, Leu-Pro-Gln, and Ser-Pro-Gln (e.g. 40.7 mg/g at pH 5.2). These gluten-derived tripeptides showed high inhibitory activity on dipeptidyl peptidase-IV with IC₅₀ values of 79.8, 70.9, 71.7, 56.7, and 78.9 μM, respectively, suggesting that the novel gluten hydrolysate prepared using ginger protease can be used as a functional food for patients with type 2 diabetes.     

Nonspecific killer cells in premature and mature neonates and infants

K (killer) and natural killer (NK) cells were investigated in peripheral blood of 76 children, preterm small for date babies (n = 8), preterm babies (n = 15), fullterm small for date babies (n = 6) fullterm babies (n = 7) and infants up to 12 months age (n = 40). The K and NK cell activity of human leukocytes was analysed as compared with those cells of the K 562 cell line and murine cells covered by xenologous antibodies in Graffi erythroblast leukemia by means of the 51Cr release test. K cell activities were significantly lower in preterm small for date babies to infants with 1-12 months of age. In our results it is shown that NK capacity of preterm or term newborns and infants up to 6 months age does not differ significantly from each other. Children who are 6-12 months old will have significantly higher NK cell activities. It can be concluded that K cell activities are fully developed during pregnancy and NK cell activities later when the children are between 6 and 12 months of age.     

Isolation and identification of root-inhibiting compounds from corn gluten hydrolysate

Interest has centered on the use of plantderived compounds as natural herbicides, and they are considered to represent an environmentally sound approach to weed control. Corn gluten hydrolysate, found to have a growth-regulating effect on the root system of germinating grass seeds, has been suggested as a natural herbicide. A protocol was developed to extract, isolate, and identify the root-inhibiting compounds from corn gluten hydrolysate aqueous solution and a perennial ryegrass (Lolium perenne L.). A Petri dish bioassay was used to test the root-inhibiting activity. Five bioactive dipeptides were isolated by using Sephadex G-15 gel filtration, solid-phase extraction, and C18 reversed-phase high-performance liquid chromatography procedures. The five dipeptides were glutaminyl-glutamine, alaninyl-asparagine, alaninyl-glutamine, glycinyl-alanine, and alaninyl-alanine. Their root-inhibiting activity on perennial ryegrass was demonstrated in Petri dish bioassays.Journal Paper No. J-15597 of Iowa Agriculture and Home Economics Experiment Station, Ames, IA Project No. 3149     

Body composition and physiological casein and wheat gluten protein requirements of 180-day-old rats

Six-month-old male rats were given diets with mounting casein and wheat gluten protein concentrations from 0% to 40% and after 14 days the optimum and minimum physiological doses were determined from changes in body nitrogen, body water, body weight and protein intake. The optimum dose for casein protein was 1.54 g/d (5% protein in the diet) and for wheat gluten protein 2.10 g/d (7.5% protein in the diet). The minimum casein and wheat gluten protein doses for 180- to 194-day-old rats, determined from body nitrogen changes, were 1499 mg/d (4.86%) and 1995 mg/d (7.12%) respectively, from body water changes 1561 mg/d (5.06%) and 2027 mg/d (7.23%) and from body weight changes 1333 mg/d (4.32%) and 1951 mg/d (6.06%). It should be noted that, unlike younger animals aged 35-49, 75-89 and 120-134 days, the optimum and minimum doses for six-month-old rats were approximately the same.     

Survival factor-like activity of small peptides in hybridoma and CHO cells cultures

Synthetic peptides containing three to six amino acid residues were previously shown to improve key parameters of monoclonal antibody-producing mouse hybridoma cultures. The aim of the current work was to investigate whether small peptides also exert analogous beneficial impact on a CHO-K1-derived cell line (XMK-111-10) engineered for production of the human model glycoprotein SEAP (secreted alkaline phosphatase). Similar to hybridoma cultures, growth and SEAP production profiles of CHO XMK-111-10 were modulated by peptides. Both viable cell density and SEAP production were increased by tetraalanine or by a fraction of wheat gluten hydrolysate. Whereas tetraglycine increased the peak viable cell density, the growth-suppressing tripeptide Gly-Lys-Gly significantly boosted SEAP production. All peptide-supplemented cultures showed slight improvement of culture viability during the decline phase of the batch cultures, suggesting a survival factor-like activity of the peptides.     

Adaptation and cultivation of permanent fish cell line CCO in serum-free medium and influence of protein hydrolysates on growth performance

In this work we describe the adaptation of channel catfish ovary (CCO) cell line to commercially available Ultra Culture serum-free medium by gradual reduction of serum concentration from 10 to 0 %. With this approach we obtained CCO cells fully adapted to serum-free conditions in 32 days. Growth, nutritional and morphological characteristics of these cells remained unchanged when compared to the control group kept in the presence of serum. Additionally, three commercially available protein hydrolysates were tested for the effects on growth performance of the newly serum-free adapted CCO cells. Supplementation with wheat gluten hydrolysate resulted in growth similar to serum free medium solely, while yeast and soy hydrolysates showed inhibitory effects on the cell growth. Taken together, the successful adaptation of CCO cells to serum-free conditions indicates their potential to be used in cytotoxicity assays when serum omission is demanded or for developing serum free bioprocesses using CCO cells. However, a more extended study on nutrient supplementation is still required to further boost the cell growth in a serum free culture.     

Fed‐batch CHO cell t‐PA production and feed glutamine replacement to reduce ammonia production

Industrial therapeutic protein production has been greatly improved through fed‐batch development. In this study, improvement to the productivity of a tissue‐plasminogen activator (t‐PA) expressing Chinese hamster ovary (CHO) cell line was investigated in shake flask culture through the optimization of the fed‐batch feed and the reduction of ammonia generation by glutamine replacement. The t‐PA titer was increased from 33 mg/L under batch conditions to 250 mg/L with daily feeding starting after three days of culture. A commercially available fed‐batch feed was supplemented with cotton seed hydrolysate and the four depleted amino acids, aspartic acid, asparagine, cysteine, and tyrosine. The fed‐batch operation increased the generation of by‐products such as lactate and ammonia that can adversely affect the fed‐batch performance. To reduce the ammonia production, a glutamine‐containing dipeptide, pyruvate, glutamate, and wheat gluten hydrolysate, were investigated as glutamine substitutes. To minimize the lag phase as the cells adjusted to the new energy source, a feed glutamine replacement process was developed where the cells were initially cultured with a glutamine containing basal medium to establish cell growth followed by feeding with a feed containing the glutamine substitutes. This two‐step feed glutamine replacement process not only reduced the ammonia levels by over 45% but, in the case of using wheat gluten hydrolysate, almost doubled the t‐PA titer to over 420 mg/L without compromising the t‐PA product quality or glycosylation pattern. The feed glutamine replacement process combined with optimizing other feed medium components provided a simple, practical, and effective fed‐batch strategy that could be applied to the production of other recombinant therapeutic proteins. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2013     

重度子痫前期患者外周血NK 细胞功能的研究*

目的:探讨重度子痫前期患者外周血中NK细胞数量、杀伤功能以及相关细胞因子的变化。方法:选择重度子痫前期患者25例(研究组)以及正常妊娠妇女25例(对照组),流式细胞术测定外周血中NK细胞数量,细胞毒实验测定NK细胞的杀伤活性,ELISA法测定血清IFN-γ及IL-2的浓度。结果:研究组患者外周血中NK细胞的数量以及杀伤活性显著高于对照组;研究组外周血中IFN-γ、IL-2的浓度也显著高于对照组。结论:重度子痫前期患者外周血NK细胞数量增多,杀伤活性增强,血清中NK细胞相关细胞因子也增加。这些改变可能参与重度子痫前期的发病机制。     

不同类型土壤上种植的不同面筋含量冬小麦品种灌浆期间籽粒中淀粉分支酶活性变化

种植在粘土、壤土和沙土中的3个面筋含量高、中、低的冬小麦品种灌浆期间籽粒中淀粉分支酶(SBE)活性变化均呈单峰曲线,开花后20 d达到峰值.面筋含量高的品种在粘土和沙土上种植的SBE活性较高,而面筋含量中等和较低的品种在粘土和壤土中种植的SBE活性较高.     

摄入含嗜酸乳杆菌NCFM和乳双歧杆菌Bi-07的益生菌补充剂增强免疫功能的动物实验研究

目的测定与验证摄入含特定乳酸菌株组合（嗜酸乳杆菌NCFM和乳双歧杆菌Bi-07）一定剂量的益生菌补充剂对动物（小鼠）免疫功能的影响。方法SPF昆明种小白鼠经口连续分别给予0．25、0．50、1．50g／kgBW的益生菌补充剂4周,进行迟发型变态反应试验、溶血素滴度测定、NK细胞活性测定等。结果在小白鼠迟发型变态反应试验中,中、高剂量组足跖增厚值均高于对照组,差异有显著性（P〈0．05）;对受试动物血清溶血素抗体滴度水平的影响的实验中,中、高剂量组的抗体积数高于对照组,差异均有显著性（P〈0．05）。NK细胞活性测定中,高剂量组脾NK细胞活性增强,差异有非常显著性（P〈0．01）。结论含该两种特定乳酸菌株的益生菌补充剂被小自鼠摄入一定剂量后,起到了增强小白鼠细胞免疫、体液免疫功能及NK细胞活性的作用。     

Determination of physiological casein and wheat gluten protein requirements of adult rats aged 75-89 days

Mounting doses of casein and wheat gluten protein (from 0% to 40% in the diet) were given to adult male rats aged 75-89 days for 14 days. The optimum physiological daily dose, determined from changes in body nitrogen, body water and body weight, was 2.76 g/d for casein protein (corresponding to a 10% casein protein diet) and 3.67 g/d for wheat gluten protein (corresponding to a 15% gluten protein diet). Determined from body weight changes, the daily maintaining dose of casein or wheat gluten protein was 1.054 and 1.511 mg/d respectively, from body nitrogen changes 970 and 1.514 mg/d and from body water changes 1.124 and 1.637 mg/d. Compared with newly weaned animals aged 35-49 days, the optimum physiological daily dietary protein doses for adult animals fall, while the maintaining doses rise.     

Wheat gluten hydrolysate potently stimulates peptide-YY secretion and suppresses food intake in rats

ABSTRACT

The study was aimed to compare the satiating effect of various protein hydrolysates in rats and examine the underlying mechanism associated with the satiety hormones. Food intake and portal satiety hormone levels were measured in rats. Enteroendocrine cell-lines were employed to study the direct effect of protein hydrolysates on gut hormone secretions. The results showed that oral preload of wheat gluten hydrolysate (WGH) suppressed food intake greater and longer than other hydrolysates. The portal peptide-YY levels in WGH-treated rats at 2 h and 3 h were higher than those in control- and lactalbumin hydrolysate (LAH)-treated rats. In a distal enteroendocrine cell model, WGH more potently stimulated glucagon-like peptide-1 secretion than LAH, and the effect was largely enhanced by pepsin/pancreatin digestion of WGH. These results suggest WGH is potent in activating enteroendocrine cells to release satiety hormones leading to the prolonged suppression of food intake.     

Daily ingestion of fermented milk containing Lactobacillus casei DN114001 improves innate defense capacity in healthy middle-aged people

Different lactic acid bacteria have often been administered as a dietary means to enhance immune system activity. Based on this statement, the aim of the current work was to test the effects of a Lactobacillus casei DN114001 fermented milk consumption on the immune response capacity in middle-age volunteers. Forty-five healthy volunteers, 24 women and 21 men (aged: 51-58 years), were randomized into two groups to receive three cups per day of a L. casei DN114001 (10(8)-10(10) ufc/g) fermented milk (n = 23), or placebo (n = 22), during an 8-week period. Measurements were performed before (day 0), and after the nutritional intervention (day 56). After the trial, no changes in immune cell proportions were detected, but the probiotic-treated group increased oxidative burst capacity of monocytes (probiotic group: p = 0.029; placebo group: p = 0.625), as well as NK cells tumoricidal activity (probiotic group: p = 0.023; placebo group: p = 0.125). Results showed that daily intake of fermented milk containing Lactobacillus casei DN114001 could have a positive effect in modulating the innate immune defense in healthy-middle-age people.     

Persistently low natural killer cell activity and circulating levels of plasma beta endorphin: risk factors for infectious disease

Beta endorphin levels were quantitated in plasma samples obtained from normal subjects (n = 81, 37% males and 63% females, age range 18-45 years) as a component of a prospective study examining the relationship of illness morbidity to natural killer cell activity and psychological indices of stress. The present study was designed to test whether beta endorphin levels contributed additionally to the explanation of illness outcome variance. In the larger study, persistently low NK (LNK) activity was associated prospectively with higher illness morbidity. The findings reported here suggest that the observed LNK activity might be affected by circulating levels of plasma beta endorphin, as lower endorphin levels predicted the LNK pattern, which in turn, predicted higher illness morbidity.     

注射液胸腺法新（日达仙）辅助希罗达联合奥沙利铂（XELOX方案）治疗 晚期胃癌的临床疗效观察

目的:探讨注射液胸腺法新(日达仙)辅助希罗达联合奥沙利铂治疗晚期胃癌的临床疗效和对患者免疫功能及生活质量的影响。方法:选择2010-2013入院治疗的晚期胃癌患者116例,随机平均分为实验组(58例)和对照组(58例)。对照组给予卡培他滨片(希罗达)联合奥沙利铂,试验组在对照组的基础上辅用注射液胸腺法新(日达仙)治疗。每治疗两到三个周期后进行一次系统疗效评估,评估项目包括影像学腹部CT、胸片、腹部彩超、血常规、尿常规、肝功、肾功,肿瘤标记物癌胚抗原(CEA)、糖类抗原(CA19-9,CA72-4)、免疫指标CD3+、CD8+、CD4/CD8、NK细胞,总治疗周期为6-8个周期。结果:实验组疾病治疗有效率为48%,对照组有效率为29%,两组比较差异具有统计学意义(p=0.041),实验组患者中位无疾病进展期(PFS)为12.5月,显著高于对照组10.1月,两组比较具有统计学意义(P0.05)。实验组患者生活质量评分、外周血CD3+、CD8+、CD4/CD8、NK细胞数量均显著优于对照组(P0.05)。结论:注射液胸腺法新(日达仙)辅助希罗达联合奥沙利铂(XELOX方案)能够提高晚期胃癌的临床疗效,改善患者的生活质量和免疫力,减少患者化疗用药的毒副反应。     

NK cell activation by dendritic cell vaccine: a mechanism of action for clinical activity

Recent reports revealed that dendritic cell (DC)–natural killer (NK) cell interaction plays an important role in tumor immunity, but few DC vaccine studies have attempted to evaluate the non-specific, yet potentially clinically relevant, NK response to immunization. In this study, we first analyzed in vitro activation of NK cells by DCs similar to those used in clinical trials. Subsequently, NK cell responses were analyzed in a phase I clinical trial of a vaccine consisting of autologous DCs loaded with a fowlpox vector encoding CEA. The data were compared with the clinical outcome of the patients. DC enhances NK activity in vitro, partly by sustaining NK cell survival and by enhancing the expression of NK-activating receptors, including NKp46 and NKG2D. Among nine patients in our clinical trial, NK cytolytic activity increased in four (range 2.5–5 times greater lytic activity) including three who had increased NK cell frequency, was stable in two and decreased in three. NKp46 and NKG2D expression showed a good correlation with the patients’ NK activity. When patients were grouped by clinical activity (stable disease/no evidence of disease (stable/NE, n=5) vs progressive disease (N=4) at 3 months), the majority in the stable/NE group had increases in NK activity (P=0.016). Anti-CEA T cell response was enhanced in all the nine patients analyzed, but was not significantly different between the two groups (P=0.14). Thus, NK responses following DC vaccination may correlate more closely with clinical outcome than do T cell responses. Monitoring of NK response during vaccine studies should be routinely performed.