Engineering SARS-CoV-2 cocktail antibodies into a bispecific format improves neutralizing potency and breadth

One major limitation of neutralizing antibody-based COVID-19 therapy is the requirement of costly cocktails to reduce antibody resistance. We engineered two bispecific antibodies (bsAbs) using distinct designs and compared them with parental antibodies and their cocktail. Single molecules of both bsAbs block the two epitopes targeted by parental antibodies on the receptor-binding domain (RBD). However, bsAb with the IgG-(scFv)2 design (14-H-06) but not the CrossMAb design (14-crs-06) increases antigen-binding and virus-neutralizing activities and spectrum against multiple SARS-CoV-2 variants including the Omicron, than the cocktail. X-ray crystallography and computational simulations reveal distinct neutralizing mechanisms for individual cocktail antibodies and suggest higher inter-spike crosslinking potentials by 14-H-06 than 14-crs-06. In mouse models of infections by SARS-CoV-2 and the Beta, Gamma, and Delta variants, 14-H-06 exhibits higher or equivalent therapeutic efficacy than the cocktail. Rationally engineered bsAbs represent a cost-effective alternative to antibody cocktails and a promising strategy to improve potency and breadth.

Expression changes in fractalkine induced by focal cerebral ischemia and reperfusion in rats / 中华老年医学杂志

Objective To investigate the expression changes of fractalkine (FKN)in focal cerebral ischemia and reperfusion penumbra,and to explore its variation law and role in the inflammation of cerebral ischemia-reperfusion injury.Methods The cerebral ischemia reperfusionmodel was established by intraluminal thread occlusion in the middle cerebral arteries occlusion (MCAO).FKN protein expression in focal cerebral ischemia and reperfusion penumbra was detected by immunohistochemistry and Western blot.Results The results of immunohistochemistry stain showed that the chemokine FKN was expressed in a low level in the normal group and the sham operation group,and there were no significant differences among the two groups (P＞ 0.05).Compared with the humbers of FKN in normal group (37.03± 6.28) in focal cerebral ischemia and reperfusion penumbra,the expression of FKN in model group was increased after 3 h of reperfusion (48.58±7.29) (P＜0.05),peaked at 24 h (112.08±8.26) (P＜0.05],and then decreased gradually at day 7 after reperfusion,but had no significant difference (40.73 ± 4.02) (P＞ 0.05).FKN was expressed in a low level in the sham operation group (0.527±0.002),then up-regulated after 3 h of reperfusion [(0.598±0.004),P＜0.05],peaked at 24 h [(0.833±0.005),P＜0.05],maintained a high level till 48 h after reperfusion [(0.735±0.002),P＜0.05],and return to baseline level at day 7 after reperfusion [(0.533±0.004),P＞0.05].Conclusions Fractalkine is upregulated after focal cerebral ischemia/reperfusion,and has a dynamical change,which indicates that fractalkine might involve in the inflammatory process after cerebral ischemia-reperfusion injury.

Effect of PD-WEBB training on balance impairment and falls in people with Parkinson's disease / 中南大学学报(医学版)

OBJECTIVE@#To determine the effect of Parkinson's disease-weight bearing exercise for better balance (PD-WEBB) exercise on balance impairment and falls in people with Parkinson's disease (PD).@*METHODS@#A single-blind, randomized controlled clinical trial was conducted. The falls efficacy scale score, unified Parkinson disease rating scale (UPDRS) score and Mini-BESTest score were measured and compared between a PD-WEBB group and a control group.@*RESULTS@#The falls efficacy scale score, UPDRS-2 score, UPDRS-3 score and Mini-BESTest score were improved in the PD-WEBB group compared with the control group (P<0.05), with no significant change in UPDRS-1 score between the two groups.@*CONCLUSION@#PD-WEBB training can significantly improve the balance impairment and quality of life to prevent falls. PD-WEBB training is suitable for PD patients in China, and is a reasonable, effective and sustainable training of family and community assessment model.

HER3 intracellular domains play a crucial role in HER3/HER2 dimerization and activation of downstream signaling pathways

Dimerization among the EGFR family of tyrosine kinase receptors leads to allosteric activation of the kinase domains of the partners. Unlike other members in the family, the kinase domain of HER3 lacks key amino acid residues for catalytic activity. As a result, HER3 is suggested to serve as an allosteric activator of other EGFR family members which include EGFR, HER2 and HER4. To study the role of intracellular domains in HER3 dimerization and activation of downstream signaling pathways, we constructed HER3/HER2 chimeric receptors by replacing the HER3 kinase domain (HER3-2-3) or both the kinase domain and the C-terminal tail (HER3-2-2) with the HER2 counterparts and expressed the chimeric receptors in Chinese hamster ovary (CHO) cells. While over expression of the intact human HER3 transformed CHO cells with oncogenic properties such as AKT/ERK activation and increased proliferation and migration, CHO cells expressing the HER3-2-3 chimeric receptor showed significantly reduced HER3/HER2 dimerization and decreased phosphorylation of both AKT and ERK1/2 in the presence of neuregulin-1 (NRG-1). In contrast, CHO cells expressing the HER3-2-2 chimeric receptor resulted in a total loss of downstream AKT activation in response to NRG-1, but maintained partial activation of ERK1/2. The results demonstrate that the intracellular domains play a crucial role in HER3's function as an allosteric activator and its role in downstream signaling.

HIF-1α and neovascularization in early carotid atherosclerosis plaques in rabbits / 中南大学学报(医学版)

OBJECTIVE@#To explore the relationship between hypoxia-inducible foctor-1α (HIF-1α) and neovascularization in early atherosclerosis plaques by establishing rabbit carotid atherosclerosis models, and to observe the value of contrast-enhanced ultrasound in the detection of neovascularization.@*METHODS@#We provided high-fat diet combined with the implantation of silicone rubber ring to establish carotid atherosclerosis in rat models. On the 14th and 28th days, we detected neovascularization in the carotid atherosclerotic plaques by contrast-enhanced ultrasound, obtained the peak intensity (PI) of the contrast agent in the plaques by time-intensity curve (TIC) and analyzed the difference. We also tested the level of HIF-1α, vascular endothelial growth factor (VEGF), cluster of differentiation 31 (CD31), α-actin, and RAM-11 by immunohistochemical method in each group, analyzed their correlation, and the correlation between PI and CD31 expression.@*RESULTS@#On the 14th day, contrast-enhanced ultrasound showed the neovascularization in the carotid atherosclerotic plaques. On the 14th and 28th days, the intensity of contrast-enhanced ultrasound showed significant difference, the mean optical density of HIF-1α, VEGF, CD31, RAM-11, and α-actin within the carotid atherosclerotic plaques also showed statistical difference. The expressions between HIF-1α and VEGF, HIF-1α and CD31, HIF-1α and RAM-11, HIF-1α and α-actin, as well as PI and CD31 showed highly positive correlations.@*CONCLUSION@#During the process of atherosclerosis evolution, neovascularization in the atherosclerotic plaques has come into being in the early period, and HIF-1α in early atherosclerosis can promote the formation of neovascularization. Contrast-enhanced ultrasound can detect the dynamic changes of neovascularization within early atherosclerotic plaques.

Expression of NF-κB gene and its significance in mouse hepatocellular carcinoma cell lines with differently lymphatic metastasis potentials / 临床与实验病理学杂志

Purpose To study NF-κB gene expression level in mouse hepatocellular carcinoma cell lines with differently lymphatic metastasis potentials and to discuss its roles in lymphatic metastasis.Methods Using real-time quantitative PCR, NF-κB gene expression level was detected in mouse hepatocellular carcinoma cell lines, including Hca-P with low lymphatic metastasis potential and Hca-F with high lymphatic metastasis potential.Results NF-κB mRNA expression in Hca-P and Hca-F cell lines were (1.41±0.48)×10~(-3),and (2.95±0.22)×10~(-3) (P<0.01),respectively.NF-κB mRNA expression levels were increased with metastasis potential.Conclusion NF-κB gene may play an important role in lymphatic metastasis of hepatocellular carcinoma.

Modified Graeb criteria for predicting the post-hemorrhagic hydrocephalus in intraventricular hemorrhage / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To set up a new grading system of intraventricular hemorrhage (IVH) and determine the value of predicting the probability of post-hemorrhagic hydrocephalus (PHH) in IVH.</p><p><b>METHODS</b>We first modified the Graeb criteria, then compared the value of prediction for PHH assessed by the Graeb criteria with the modified Graeb criteria. One hundred and thirty one IVH patients were divided into two groups: the upper group (n = 67) and the lower group (n = 64). Gold standard of PHH was assessed by CT scan or by out-drainage. The diagnostic parameters such as sensitivity (SE), specificity (SP) were analyzed. In the cutoff point of SE and SP curves, diagnostic efficiency (DE), and Kappa value (K) were analyzed. The probability of PHH was estimated by binary logistic regressions.</p><p><b>RESULTS</b>In all ventricular group, to Graeb criteria in the cutoff point, SE, SP, and K was 0.78, 0.84, and 0.60; and to modified Graeb criteria SE, SP, and K was 0.90, 0.84, and 0.74 respectively. The probability of PHH from point of 3-12 was 0.011, 0.032, 0.085, 0.212, 0.435, 0.689, 0.865, 0.949, 0.981, and 0.994 respectively according to modified Graeb criteria.</p>