High performance production process development and scale-up of an anti-TSLP nanobody

Nanobodies (Nbs) represent a class of single-domain antibodies with great potential application value across diverse biotechnology fields, including therapy and diagnostics. Thymic Stromal Lymphopoietin (TSLP) is an epithelial cell-derived cytokine, playing a crucial role in the regulation of type 2 immune responses at barrier surfaces such as skin and the respiratory/gastrointestinal tract. In this study, a method for the expression and purification of anti-TSLP nanobody (Nb3341) was established at 7 L scale and subsequently scaled up to 100 L scale. Key parameters, including induction temperature, methanol feed and induction pH were identified as key factors by Plackett-Burman design (PBD) and were optimized in 7 L bioreactor, yielding optimal values of 24 °C, 8.5 mL/L/h and 6.5, respectively. Furthermore, Diamond Mix-A and Diamond MMC were demonstrated to be the optimal capture and polishing resins. The expression and purification process of Nb3341 at 100L scale resulted in 22.97 g/L titer, 98.7% SEC-HPLC purity, 95.7% AEX-HPLC purity, 4 ppm of HCP content and 1 pg/mg of HCD residue. The parameters of the scaling-up process were consistent with the results of the optimized process, further demonstrating the feasibility and stability of this method. This study provides a highly promising and competitive approach for transitioning from laboratory-scale to commercial production-scale of nanobodies.

TROP2-directed nanobody-drug conjugate elicited potent antitumor effect in pancreatic cancer

BACKGROUND

Pancreatic cancer is a highly aggressive malignancy with limited treatment options and a poor prognosis. Trophoblast cell surface antigen 2 (TROP2), a cell surface antigen overexpressed in the tumors of more than half of pancreatic cancer patients, has been identified as a potential target for antibody-drug conjugates (ADCs). Almost all reported TROP2-targeted ADCs are of the IgG type and have been poorly studied in pancreatic cancer. Here, we aimed to develop a novel nanobody-drug conjugate (NDC) targeting TROP2 for the treatment of pancreatic cancer.

RESULTS

In this study, we developed a novel TROP2-targeted NDC, HuNbTROP2-HSA-MMAE, for the treatment of TROP2-positive pancreatic cancer. HuNbTROP2-HSA-MMAE is characterized by the use of nanobodies against TROP2 and human serum albumin (HSA) and has a drug-antibody ratio of 1. HuNbTROP2-HSA-MMAE exhibited specific binding to TROP2 and was internalized into tumor cells with high endocytosis efficiency within 5 h, followed by intracellular translocation to lysosomes and release of MMAE to induce cell apoptosis in TROP2-positive pancreatic cancer cells through the caspase-3/9 pathway. In a xenograft model of pancreatic cancer, doses of 0.2 mg/kg and 1 mg/kg HuNbTROP2-HSA-MMAE demonstrated significant antitumor effects, and a dose of 5 mg/kg even eradicated the tumor.

CONCLUSION

HuNbTROP2-HSA-MMAE has desirable affinity, internalization efficiency and antitumor activity. It holds significant promise as a potential therapeutic option for the treatment of TROP2-positive pancreatic cancer.

Identification and Characterization of a Novel Nanobody Against Human CTGF to Reveal Its Antifibrotic Effect in an in vitro Model of Liver Fibrosis

Background

No agents are currently available for the treatment or reversal of liver fibrosis. Novel antifibrotic therapies for chronic liver diseases are thus urgently needed. Connective tissue growth factor (CTGF) has been shown to contributes profoundly to liver fibrogenesis, which makes CTGF as a promising target for developing antifibrotic agents.

Methods

In this study, we identified a novel nanobody (Nb) against human CTGF (anti-CTGF Nb) by phage display using an immunized camel, which showed high affinity and specificity in vitro. LX-2 cells, the immortalized human hepatic stellate cells, were induced by transforming growth factor beta1 (TGFβ1) as an in vitro model of liver fibrosis to verify the antifibrotic activity of the anti-CTGF Nb.

Results

Our data demonstrated that anti-CTGF Nb effectively alleviated TGFβ1-induced LX-2 cell proliferation, activation, and migration, and promoted the apoptosis of activated LX-2 cells in response to TGFβ1. Moreover, the anti-CTGF Nb remarkably reduced the levels of TGFβ1, Smad2, and Smad3 expression in LX-2 stellate cells stimulated by TGFβ1.

Conclusion

Taken together, we successfully identified a novel Nb against human CTGF, which exhibited antifibrotic effects in vitro by regulating the biological functions of human stellate cells LX-2.

Preclinical development of a long-acting trivalent bispecific nanobody targeting IL-5 for the treatment of eosinophilic asthma

Background

Eosinophilic asthma is a common subtype of severe asthma with high morbidity and mortality. The cytokine IL-5 has been shown to be a key driver of the development and progression of disease. Although approved monoclonal antibodies (mAbs) targeting IL-5/IL-5R have shown good safety and efficacy, some patients have inadequate responses and frequent dosing results in medication nonadherence.

Results

We constructed a novel trivalent bispecific nanobody (Nb) consisting of 3 VHHs that bind to 2 different epitopes of IL-5 and 1 epitope of albumin derived from immunized phage display libraries. This trivalent IL-5-HSA Nb exhibited similar IL-5/IL-5R blocking activities to mepolizumab (Nucala), an approved targeting IL-5 mAb. Surprisingly, this trivalent Nb was 58 times more active than mepolizumab in inhibiting TF-1-cell proliferation. In primate studies, the trivalent IL-5-HSA Nb showed excellent pharmacokinetic properties, and peripheral blood eosinophil levels remained significantly suppressed for two months after a single dose. In addition, the trivalent IL-5-HSA Nb could be produced on a large scale in a P. pastoris X-33 yeast system with high purity and good thermal stability.

Conclusions

These findings suggest that the trivalent bispecific IL-5-HSA Nb has the potential to be a next-generation therapeutic agent targeting IL-5 for the treatment of severe eosinophilic asthma.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02240-1.

[A preliminary investigation of the clinical characteristics of community acquired pneumonia with concomitant pulmonary embolism]

Objective: To understanding the clinical characteristics of the patients of pneumonia concomitant with acute pulmonary embolism, and the early identification of high-risk patients. Methods: Retrospective analysis of hospitalized patients with confirmed diagnosis of community acquired pneumonia (CAP) with concomitant pulmonary embolism (PE) within a period of 5 years. Patients hospitalized with CAP alone in the same period were included in the control group in a ratio of 1∶2 according to the principle of gender and age. The demographic characteristics, clinical feature, laboratory examination, radiographic and other clinical data of these 2 groups of patients were studied. Statistical analysis was performed by Chi-square test, Kruskal-Wallis test and logistic regression. Results: Thirty-nine patients with CAP combined with PE and 78 patients with CAP alone were included. Compared to patients with CAP alone, dyspnea (21/39 vs 21/78, P=0.004), a history of heart disease (10/39 vs 8/78, P=0.031), and a history of connective tissue diseases (3/39 vs 0/78, P=0.035) were more common to seen in patients with CAP combined with PE. D-dimer [2 222(854, 3 539) ng/ml vs 295(168, 707) ng/ml, P=0.000], arterial PH value (7.5±0.5 vs 7.4±0.4, P=0.022), BNP [103.9(48.7, 236.8) pg/ml vs 98.4(44.8, 246.3) pg/ml, P=0.028] and incidence of lower extremity venous thrombosis (18/39 vs 3/41, P=0.000) were higher in patients with CAP combined with PE, while arterial partial pressure of CO₂ [(35.3±6.2) mmHg vs (38.4±4.4) mmHg, P=0.009, 1 mmHg=0.133 kPa] was lower. Logistic regression analysis showed that D-dimer (P=0.000) and dyspnea (P=0.033) were associated with the risk of PE. Conclusion: When patients with CAP represent dyspnea or have a history of heart disease or connective tissue diseases concomitant PE should be considered for differential diagnosis. Determination of D-dimer, arterial PH value, arterial partial pressure of CO₂, BNP and ultrasonography of lower extremities had important implications for the diagnosis of pneumonia complicated with acute pulmonary embolism.

Identifying Risks for Persistent Postconcussive Symptoms in a Pediatric Emergency Department: An Examination of a Clinical Risk Score

OBJECTIVE

External examination of a clinical risk score to predict persistent postconcussive symptoms (PPCS) in a pediatric emergency department (ED).

METHODS

Prospective cohort study of 5- to 18-year-old patients diagnosed with an acute concussion. Risk factors were collected at diagnosis and participants (n = 85) were followed to determine PPCS 30 days postinjury. Univariate logistic regression analyses were completed to examine associations of risk factors with PPCS.

RESULTS

Headache and total clinical risk score were associated with increased odds of PPCS in the univariate analyses, OR 3.37 (95% CI 1.02, 11.10) and OR 1.25 (95% CI 1.02, 1.52), respectively. Additionally, teenage age group, history of prolonged concussions, and risk group trended toward association with PPCS, OR 4.79 (95% CI 0.93, 24.7), OR 3.41 (95% CI 0.88, 13.20), and OR 2.23 (95% CI 0.88, 5.66), respectively.

CONCLUSION

Our study supports the use of multiple variables of a clinical risk score to assist with ED risk stratification for pediatric patients at risk for PPCS.

A potent neutralizing nanobody against SARS-CoV-2 with inhaled delivery potential

The coronavirus disease 2019 (COVID‐19) pandemic has become a serious burden on global public health. Although therapeutic drugs against COVID‐19 have been used in many countries, their efficacy is still limited. We here reported nanobody (Nb) phage display libraries derived from four camels immunized with the SARS‐CoV‐2 spike receptor‐binding domain (RBD), from which 381 Nbs were identified to recognize SARS‐CoV‐2‐RBD. Furthermore, seven Nbs were shown to block interaction of human angiotensin‐converting enzyme 2 (ACE2) with SARS‐CoV‐2‐RBD variants and two Nbs blocked the interaction of human ACE2 with bat‐SL‐CoV‐WIV1‐RBD and SARS‐CoV‐1‐RBD. Among these candidates, Nb11‐59 exhibited the highest activity against authentic SARS‐CoV‐2 with 50% neutralizing dose (ND₅₀) of 0.55 μg/ml. Nb11‐59 can be produced on large scale in Pichia pastoris, with 20 g/L titer and 99.36% purity. It also showed good stability profile, and nebulization did not impact its stability. Overall, Nb11‐59 might be a promising prophylactic and therapeutic molecule against COVID‐19, especially through inhalation delivery.

Preclinical development of a novel CD47 nanobody with less toxicity and enhanced anti-cancer therapeutic potential

BACKGROUND

CD47, the integrin-related protein, plays an important role in immune resistance and escape of tumor cells. Antibodies blocking the CD47/SIRPα signal pathway can effectively stimulate macrophage-mediated phagocytosis of tumor cells, which becomes a promising approach for tumor immunotherapy. Nanobodies (Nbs) derived from camelid animals are emerging as a new force in antibody therapy.

RESULTS

HuNb1-IgG4, an innovative anti-CD47 nanobody, was developed with high affinity and specificity. It effectively enhanced macrophage-mediated phagocytosis of tumor cells in vitro and showed potent anti-ovarian and anti-lymphoma activity in vivo. Importantly, HuNb1-IgG4 did not induce the agglutination of human red blood cells (RBCs) in vitro and exhibited high safety for hematopoietic system in cynomolgus monkey. In addition, HuNb1-IgG4 could be produced on a large scale in CHO-S cells with high activity and good stability. Also, we established anti-CD47/CD20 bispecific antibody (BsAb) consisted of HuNb1 and Rituximab, showing more preference binding to tumor cells and more potent anti-lymphoma activity compared to HuNb1-IgG4.

CONCLUSIONS

Both of HuNb1-IgG4 and anti-CD47/CD20 BsAb are potent antagonists of CD47/SIRPα pathway and promising candidates for clinical trials.

Blocking the PD-1-PD-L1 axis by a novel PD-1 specific nanobody expressed in yeast as a potential therapeutic for immunotherapy

PD-1/PD-L1 pathway blocking with antibodies offers a vital and efficient therapeutic strategy to restore T cell-associated antitumor immunity and treats a variety of cancers in clinic. Nanobodies (Nbs) give several advantages over conventional monoclonal antibodies such as size, solubility, stability and costs. Additionally, P. pastoris is a suitable host for Nb production. Herein, we aim to produce and evaluate anti-PD-1 Nb derived from the P. pastoris. Our findings indicated that we successfully established the Nbs phage-displayed library against PD-1 with qualified library capacity and insert ratio. Anti-PD-1 Nb Nb97 was screened through PE-ELISA and flow cytometry. To extend half-life of Nb97, we contracted pPICZɑA-Nb97-Nb97-HSA recombination vector, which was then transformed into the system of P. pastoris X-33. The yield of purified Nb97-Nb97-Human serum albumin (HSA) fused protein (MY2935) reached to 2.3 g/L after 147 h of fermentation. Meanwhile, the blocking effect of MY2935 is similar to that of MY2626 (humanized Nb97-Fc), and MY2935 showed better performance on stimulating the immune function through PD-1 reporter assay. Hence, P. pastoris X-33 expressing and secreting functional anti-PD-1 Nb-HSA fusion protein might be a system of high yield and low cost.

Increased H2S and its synthases in urothelial cell carcinoma of the bladder, and enhanced cisplatin-induced apoptosis following H2S inhibition in EJ cells

H²S, synthesized by cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (MPST), functions as a signalling molecule in mammalian cells. H²S serves complex functions in physiological and pathological processes, including in bladder cancer. In the present study, H²S production, the expression of the associated enzymes and the effect of H²S on human urothelial cell carcinoma of the bladder (UCB) tissue and cell lines were evaluated, and whether decreasing H²S levels influenced cell viability and tumour growth following treatment with cisplatin (CDDP) was assessed in UCB cells in vitro and in vivo. H²S production and the expression of CBS, CSE and MPST in bladder tissue specimens and the UCB cell lines 5637, EJ and UM-UC-3 were analysed using a sulfur-sensitive electrode and western blotting. UCB cells were subjected to different treatments, and viability and protein expression were determined. H²S production was inhibited to examine its influence on EJ cell tumour growth following CDDP treatment in vivo. It was identified that CBS, CSE and MPST protein were up-regulated in UCB tissues and cells. The H²S production and enzyme expression levels were the highest in UCB tissue and EJ cells. The inhibition of endogenous H²S biosynthesis decreased EJ cell viability and tumour growth in response to CDDP treatment. H²S levels and the associated biosynthetic enzymes were increased in human UCB tissue and cells compared with adjacent tissue and normal cells, which may have increased the resistance to CDDP-induced apoptosis in UCB. Therefore, H²S and its production may be an alternative therapeutic target for UCB.

Depletion of tissue factor suppresses hepatic metastasis and tumor growth in colorectal cancer via the downregulation of MMPs and the induction of autophagy and apoptosis

Tissue factor (TF) is a significant risk factor for hepatic metastasis in patients with colorectal cancer (CRC). However, the mechanism by which TF promotes hepatic metastasis in CRC remains elusive. In this study, we first confirmed that TF expression was significantly correlated with lymph node metastasis, hepatic metastasis and TNM staging in clinical CRC samples, and found that TF expression in colon cancer cell lines was correlated with the invasion ability. Next, by employing TF-overexpressing LOVO cell line as a model we demonstrated that lentivirus mediated knockdown of TF suppressed the migration and invasion of LOVO cells in vitro, and hepatic metastasis of colorectal cancer in nude mice orthotopic model. Mechanistically, we found that TF knockdown decreases colony formation ability and induced autophagy and apoptosis of LOVO cells, and this was at least partly mediated by the activation of unfolded protein response/PERK signaling. In conclusion, our data provide new insight into hepatic metastasis of CRC. Agents targeting TF should be developed as adjuvant therapeutics for CRC metastasis.

[Identification of major gene and polygene mixed inheritance model and estimation of genetic parameters of a quantitative trait from F2 progeny]

It has been proved by many field experiments and QTL mapping results that among genes affecting some quantitative traits there are some major genes with larger genetic effect and some polygenes with smaller genetic effect. For such traits, the distribution of segregating population demonstrates multimodality, and this is the characteristic of the mixture of more than one distributions. Mixture distribution models have been used extensively as models in a wide variety of practical situations where data can be viewed as arising from two or more populations mixed in certain proportions. Akaike's Information Criterion(AIC) has been used to identify the existence of major genes affecting quantitative traits. Under the existence of major genes, the genetic effects of these genes and their genetic variance were estimated through segregation analysis. The genotype of major gene of F2 individuals of were determined by clustering using Bayesian criterion. With P1, P2, F1 and F2 populations, the likelihood ratio test was used to test the existence of polygenes. In the end, the inheritance of soybean flowering date is analyzed. One major gene was found in F2 population derived from Guludou x Shanghaihongmangzao.

Soybean Disease Loss Estimates for the Top 10 Soybean Producing Countries in 1994

Soybean disease loss estimates were compiled for the 1994 harvested crop from the 10 countries with the greatest soybean production. The objective was to document the major soybean disease problems in these countries and any recent changes in the severity of individual soybean diseases. Total yield losses caused by Heterodera glycines in these 10 countries were greater than those caused by any other disease. Next in order of importance were stem canker, brown spot, and charcoal rot. The total yield loss due to disease during 1994 in these countries was 14.99 million metric tons, valued at $3.31 billion. Methods used to estimate soybean disease losses were field surveys, plant disease diagnostic clinic samples, variety trial data, information from field workers and university extension staff, research plots, grower demonstrations, and private crop consultant reports. Yield loss estimates due to a particular disease varied by country. For example, yield losses due to rust were reported from China and Indonesia, but no losses due to this disease were reported from any of the remaining eight countries. Soybean disease control research and extension efforts are needed to provide more effective preventive and therapeutic disease management strategies and systems to producers.

Effect of SR 59026A, a new 5-HT(1A) receptor agonist, on sexual activity in male rats

The effect of SR 59026A, a new selective 5-HT(1A) receptor agonist, was evaluated on sexual behaviour of male rats in different experimental conditions. SR 59026A (1-10mg/kg p.o.) stimulated the copulatory behaviour of sexually experienced rats, as evidenced by a decrease in the number of pre-ejaculatory mounts and intromissions and a shortening of the ejaculation latency. SR 59026A also facilitated the sexual behaviour of naive male rats characterized by a low level of sexual performance: over the same dose range, the percentage of naive males that copulated was significantly increased and the ejaculation latency reduced. In experiments designed to evaluate the onset of sexual satiation, SR 59026A (1 and 3mg/kg) increased significantly the number of ejaculations and delayed the time of sexual satiation. Finally, in agreement with studies on other 5-HT(1A) receptor agonists, SR 59026A did not modify the occurrence of spontaneous erections in isolated male rats. Therefore, the present study shows that SR 59026A improves the sexual performance of male rats in a number of different experimental models, and the compound may prove to be of interest for the treatment of certain states of human male sexual dysfunction.