1.Analysis of the impact of intraoperative RhE antigen-matched transfusion on early prognosis in liver transplant patients
Xiaochao YU ; Xinyuan GAO ; Fan HAI ; Chao YANG ; Xingyu HOU ; Yaping XING ; Hongqiang GAO ; Hongwei ZHANG ; Gang SU ; Ronghua XU
Chinese Journal of Blood Transfusion 2026;39(1):44-50
Objective: To investigate the impact of RhE antigen-matched transfusion during liver transplantation on early postoperative recovery and complications. Methods: In this retrospective cohort study, ninety-five patients undergoing liver transplantation at Kunming First People's Hospital between January 2022 and July 2025 were enrolled. Patients were divided into two groups: Group 1 (RhE-mismatched transfusion, n=57) and Group 2 (RhE-matched transfusion, n=38). The baseline data, complete blood counts, hepatic and renal function, coagulation parameters, and complication rates between the two groups were compared at postoperative days 1, 3, 5, 7, and 10. Survival analysis was performed using the Kaplan-Meier method. Results: The baseline characteristics were well-balanced and comparable between the two groups (all P>0.05). The early postoperative mortality rate in the mismatched group (31.58%, 18/57) was significantly higher than that in the matched group (10.53%, 4/38) (P=0.017). The incidence of postoperative hepatic encephalopathy was significantly higher in the mismatched group (50.88%, 29/57) than in the matched group (10.53%, 4/38) (P<0.001). The incidence of postoperative haemorrhage in the mismatched group (24.56%, 14/57) was higher than that in the matched group (5.26%, 2/38), with a statistically significant difference (P=0.014). The incidence of perioperative infection in the mismatched group (28.07%, 16/57) was higher than that in the matched group (10.53%, 4/38), with a statistically significant difference (P=0.04). Corresponding odds ratios (OR) and 95% confidence intervals indicated a lower risk of these adverse events in the matched group. On postoperative day 1, the change in activated partial thromboplastin time (-1.6, 20.5) in the mismatched group was greater than in the matched group (-0.2, 5.5). The change in international normalised ratio (-0.56, 1.22) in the mismatched group was greater than in the matched group (-0.18, 0.32), while the change in albumin (-4.0, 4.8) was smaller in the mismatched group than in the matched group (-2.5, 8.8). On postoperative day 5, the change in albumin (-0.41±7.83) in the mismatched group was smaller than in the matched group (2.68±4.53). At postoperative day 7, the change in albumin in the mismatched group (-0.61±7.38) was smaller than that in the matched group (2.51±5.85), while the change in D-dimer in the mismatched group (0.73, 7.4) was greater than that in the matched group (-1.6, 4.3). On postoperative day 10, the mismatched group exhibited significantly higher fibrinogen levels (-1.21, 1.78) than the matched group (-0.49, 0.97), and significantly longer prothrombin times (-11.3, -2.7) than the matched group (-6.2, -0.8) (all P<0.05). The matched group exhibited a mean overall survival (OS) of 32.803 months (95% CI:29.171-36.436 months), significantly exceeding the mismatched group's 28.996 months (95% CI:24.202-33.790 months). The log-rank test yielded statistically significant results (χ
=4.307, P=0.038). Conclusion: Implementing RhE blood group-matched transfusion during liver transplantation may help reduce early postoperative mortality and the incidence of major complication rates, promote faster recovery of coagulation and liver function, and thereby improve short-term patient outcomes.
2.Study on the compatibility stability of 16 commonly used intravenous antibiotics in ICU
Liting ZHANG ; Haotian YANG ; Siqi YU ; Liju FAN ; Jing AN
China Pharmacy 2026;37(4):468-475
OBJECTIVE To systematically analyze the compatibility stability of commonly used intravenous antibiotics in the intensive care unit (ICU), and to provide evidence-based support for rational clinical drug use. METHODS Medication data from the ICU of Hebei General Hospital between January and December 2024 were extracted from the Prescription Automatic Screening System. Commonly used intravenous antibiotics and other intravenous drugs in the ICU were selected through consultations with critical care and pharmacy experts in Hebei province, drug package inserts and compatibility information retrieved from Micromedex, Trissel’s Injectable Drug Handbook and PubMed. The physicochemical stability of drug combinations was analyzed. In addition, Cytoscape 3.10.2 software was used to construct a drug compatibility network for identifying high-risk drugs. RESULTS &CONCLUSIONS A total of 904 pairwise drug combinations involving 16 antibacterial agents and 65 intravenous drugs were collected. Among them, 549 combinations (60.7%) were compatible, 88 combinations (9.7%) were incompatible, 82 combinations (9.1%) had conflicting evidence, and 185 combinations (20.5%) lacked valid data support. High-risk combination drugs primarily involved Amphotericin B for injection, Ceftazidime for injection, Imipenem-cilastatin for injection, Ceftriaxone sodium for injection, Vancomycin hydrochloride for injection, etc. The main risk factors for drug-drug incompatibility included drug concentration, temperature, mixing rate, pH, and chemical structure. In clinical practice, drugs and diluents should be selected rationally based on specific compatibility data, and research and monitoring of drug compatibility should be further strengthened.
3.Mechanisms of Dihuang Yinzi in Treating Advanced Parkinson's Disease Based on Gut Microbiota-SCFAs-inflammation Axis
Renzhi MA ; Yasi LIN ; Tingyue JIANG ; Hongmei ZHU ; Jiayuan LI ; Yu WANG ; Ge ZHANG ; Wenxin FAN ; Jinli SHI
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(7):11-21
ObjectiveTo observe the effects of Dihuang Yinzi (DY) on motor dysfunction in rats with advanced Parkinson's disease (PD) and to investigate the mechanisms by which DY improves advanced PD symptoms through the "gut microbiota-short-chain fatty acids (SCFAs)-inflammation-neuroprotection pathway". MethodsAn advanced PD rat model was induced by rotenone. Rats were divided into a normal group, model group, positive drug group (levodopa, 50 mg·kg-1), and DY low-, medium-, and high-dose groups (5.2, 10.4, 20.8 g·kg-1). After 7 days of administration, motor function was evaluated using the open-field, pole-climbing, and inclined plate tests. Hematoxylin-eosin (HE) staining was used to observe pathological changes in the substantia nigra and colon, and immunohistochemistry was performed to detect α-Synuclein (α-Syn) and tyrosine hydroxylase (TH) expression in the substantia nigra. Enzyme-linked immunosorbent assay (ELISA) was used to measure levels of dopamine (DA), 5-hydroxytryptamine (5-HT), 3,4-dihydroxyphenylacetic acid (DOPAC), Levodopa, homovanillic acid (HVA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β). Western blot analysis was used to detect the expression of zonula occludens-1 (ZO-1) and occludin. Gut microbiota diversity was analyzed by 16S rRNA sequencing, and gas chromatography (GC) was used to determine the content of SCFAs in colonic contents. ResultsCompared with the normal group, the model group showed significantly decreased movement speed and distance in the open-field test, prolonged pole-climbing time, and reduced retention angle on the inclined plate (P<0.01), accompanied by increased α-Syn expression (P<0.01) and decreased TH expression (P<0.01) in the brain. Compared with the model group, all DY dose groups improved motor dysfunction in advanced PD rats to varying degrees (P<0.05, P<0.01) and alleviated pathological damage in the brain and colon. High-dose DY significantly reduced α-Syn aggregation in the substantia nigra (P<0.01) and increased TH expression (P<0.01). ELISA and Western blot results showed that, compared with the normal group, the model group exhibited decreased levels of DA, 5-HT, DOPAC, Levodopa, and HVA in the striatum (P<0.01), increased levels of TNF-α, IL-6, and IL-1β in the colon and striatum (P<0.01), and significantly reduced expression of ZO-1 (P<0.05) and occludin in the colon (P<0.01). Compared with the model group, all DY dose groups increased the levels of DA, 5-HT, DOPAC, Levodopa, and HVA in the striatum to varying degrees (P<0.05, P<0.01). In the high-dose DY group, the levels of TNF-α, IL-6, and IL-1β in the colon and striatum were reduced (P<0.01), while the expression of ZO-1 (P<0.05) and occludin in the intestine was increased. The 16S rRNA sequencing results indicated that the relative abundances of Actinobacteriota, Enterobacteriaceae, and Erysipelotrichaceae were increased in the model group, whereas the relative abundances of Bacteroidota, class Clostridia, Lachnospiraceae, and Akkermansia muciniphila were decreased. These changes were effectively reversed after high-dose DY intervention. GC analysis showed that the content of SCFAs in the colonic contents of rats in the model group was decreased (P<0.05, P<0.01), while after high-dose DY intervention, the levels of acetate, propionate, isobutyrate, and butyrate were significantly increased (P<0.05, P<0.01). ConclusionDY may exert therapeutic effects in advanced PD by regulating the gut microbiota-SCFAs-inflammation pathway.
4.Research progress on the bidirectional association between periodontal disease and depression/anxiety
WANG Liwen ; CAI Yutai ; RUAN Yaru ; ZHANG Fan ; YU Hongmei ; GAO Yanhui
Journal of Prevention and Treatment for Stomatological Diseases 2026;34(3):281-291
There are practical and cost-effective opportunities for the prevention and early intervention of periodontal disease, a common oral condition. Depression and anxiety represent major global mental health challenges, and they are characterized by high prevalence rates and an elevated suicide risk. Their clinical management is complicated by extended treatment timelines and substantial healthcare costs. Accumulating evidence demonstrates a statistically significant bidirectional association between periodontal disease and depression/anxiety disorders. However, established clinical pathways integrating these conditions remain lacking. This review presents a comprehensive analysis of current research examining the relationship between periodontal disease and mood disorders, specifically depression and anxiety. This study explored the bidirectional mechanisms within the microbiota-oral-brain axis, which includes both periodontal disease inducing neuroinflammation through pro-inflammatory factors, such as interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) activating the TLR-4/NF-κB signaling pathway, and depression and anxiety leading to “glucocorticoid resistance” through hypothalamic-pituitary-adrenal (HPA) axis dysregulation, thus causing dual immune dysfunction that exacerbates periodontal tissue destruction, as well as the mechanisms by which biological, psychological, and social factors contribute to the bidirectional association between periodontal disease and depression/anxiety. We propose implementing bidirectional referral protocols between dental and psychiatric services in clinical practice, incorporating mental health screening tools, such as Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7(GAD-7), for patients with moderate-to-severe periodontal disease, and incorporating periodontal examination into routine assessment during psychiatric services. This multidisciplinary approach aims to break the vicious circle between these conditions and provide clinicians with pragmatic intervention strategies.
5.Association between occupational noise exposure and depressive symptoms among employees in a petrochemical enterprise
Jianye PENG ; Zhuna SU ; Ruilian MO ; Jiaxin LI ; Qisheng WU ; Shiheng FAN ; Bingxian ZHOU ; De’e YU ; Jing ZHANG
Journal of Environmental and Occupational Medicine 2026;43(2):189-195
Background Depressive symptoms have become a significant factor affecting the physical and mental health of the occupational population, and workers in petroleum refining enterprises face multiple stressors in their work environment. Objective To explore the impact of occupational noise exposure on depressive symptoms among workers in a petroleum refining enterprise. Methods This cross-sectional study was conducted in July 2024 using a questionnaire survey among workers of a petroleum refining enterprise in Hainan Province. Basic information of the subjects was collected. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to measure depressive symptoms, the Chinese version of the Pittsburgh Sleep Quality Index (PSQI) scale was used to assess sleep quality, and the Chinese version of the Effort-Reward Imbalance (ERI) scale was used to evaluate occupational stress. Chi-square test was employed to compare the differences in reporting depressive symptoms among populations with different characteristics. Binary logistic regression models were used to analyze the impact of occupational noise exposure and other factors on depressive symptoms. Results The overall positive rate of depressive symptoms in the study population was 42.7%. The results of the multifactor analysis indicated that compared with the control group, employees in both the low-exposure and high-exposure groups had elevated odds of depressive symptoms, with OR (95%CI) of 2.244 (1.131, 4.454) and 1.970 (1.009, 3.850), respectively. This association remained robust after adjusting for potential confounders, including gender, age, work tenure, and other occupational exposures. Additionally, female [OR (95%CI)=1.483 (1.039, 2.118)], exposure to benzene, toluene, or xylene [OR (95%CI)=1.621 (1.208, 2.174)], sleep disturbance [OR (95%CI)=3.772 (2.942, 4.838)], and occupational stress [OR (95%CI)=2.018 (1.575, 2.585)] were also significantly associated with higher odds of depressive symptoms. Conclusion The positive rate of depressive symptoms is relatively high among employees in this petrochemical enterprise, and occupational noise exposure may be a risk factor for depressive symptoms.
6.Fufang Kangjiaolv Capsules Treat Anxiety in Rat Model of Chronic Restraint Stress via Microbiota-gut-brain Axis
Wenxin FAN ; Tingyue JIANG ; Yu WANG ; Ge ZHANG ; Yifan LU ; Mengmeng LIU ; Jiayuan LI ; Renzhi MA ; Jinli SHI
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(4):95-107
ObjectiveTo observe the intervention effect of Fufang Kangjiaolv capsules on anxiety-like behaviors in the rat model of chronic restraint stress (CRS) and explore the mechanism underlying the anti-anxiety effect via the microbiota-gut-brain axis. MethodsRats were assigned into blank, model, positive drug (diazepam, 1 mg·kg-1), and low-, medium-, and high-dose (0.75, 1.5, 3 g·kg-1, respectively) Fufang Kangjiaolv capsules groups. After 14 days of administration, the elevated plus maze test, open field test, light and dark box test, and marble burying test were performed. Hematoxylin-eosin staining was employed to observe the pathological changes in the hippocampus and colon of rats, and Nissl staining was conducted to observe the damage of hippocampal neurons. The gut microbiota was analyzed by 16S rRNA gene sequencing. Real-time fluorescence quantitative polymerase chain reaction (Real-time PCR) was employed to determine the mRNA levels of zonula occludens-1 (ZO-1) and occludin in the colon of rats. The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in the colon, serum, and hippocampus were determined by enzyme-linked immunosorbent assay. Western blot was employed to determine the protein levels of ZO-1, occludin, nuclear factor-κB p65 (NF-κB p65) in the colon tissue and NF-κB p65 and brain-derived neurotrophic factor (BDNF) in the hippocampal tissue. ResultsCompared with the blank group, the model group showed reductions in the time and frequency ratio of rats entering the elevated plus maze, the time and frequency of rats entering the central area of the open field, the time of entering the open box, the times of passing through the light and dark box, and the number of unburied beads (P<0.05, P<0.01). Compared with the model group, Fufang Kangjiaolv capsules ameliorated the anxiety of the model rats to varying degrees, and the high-dose group had the best effect, with increases in the proportions of time and frequency of rats entering the open arm in the elevated plus maze (P<0.05), the number of rats entering the central area in the open field (P<0.05), the time of entering the open box, the times of passing through the light and dark boxes, and the number of unburied beads (P<0.01). Moreover, the high-dose group showed alleviated pathological damage of hippocampal neurons and colon. The results of 16S rRNA gene sequencing showed that the model group had increased relative abundance of Firmicutes, Deferribacterota, Romboutsia, and Phascolarctobacterium, while it had decreased relative abundance of Bavcteroidota and Lactobacillus. The drug administration groups showed increased relative abundance of Bavcteroidota, Bacteroides, norank f norank o Clostridia UCG-014, and Blautia and decreased relative abundance of Firmicutes and Deferribacterota. Compared with the blank group, the model group showed down-regulated protein and mRNA levels of ZO-1 and occludin in the colon (P<0.01), elevated levels of TNF-α, IL-6, and IL-β in the colon, serum, and hippocampus (P<0.01), up-regulated protein level of NF-κB p65 in the colon and hippocampus (P<0.01), and down-regulated protein level of BDNF in the hippocampus (P<0.05). Compared with the model group, high-dose Fufang Kangjiaolv capsules up-regulated the mRNA levels of ZO-1 and occludin in the colon (P<0.01), lowered the levels of TNF-α, IL-6, and IL-β in the colon, serum, and hippocampus (P<0.01), up-regulated the protein levels of ZO-1 (P<0.01) and occludin (P<0.05) in the colon, down-regulated the protein level of NF-κB p65 in the colon and hippocampus (P<0.05), and up-regulated the protein level of BDNF in the hippocampus. ConclusionFufang Kangjiaolv capsules can reduce the anxiety-like behaviors in the rat model of CRS by regulating the gut microbiota disturbance, up-regulating the expression of tight junction proteins in the colon, repairing intestinal mucosal mechanical barrier, and down-regulating NF-κB/BDNF signaling pathway, thereby reducing peripheral and central inflammation. This study proves the hypothesis that Fufang Kangjiaolv capsules play an anti-anxiety role via the microbiota-gut-brain axis, providing a new idea for further research.
7.Effects of polylactic acid-glycolic acid copolymer/lysine-grafted graphene oxide nanoparticle composite scaffolds on osteogenic differentiation of MC3T3 cells
Shuangqi YU ; Fan DING ; Song WAN ; Wei CHEN ; Xuejun ZHANG ; Dong CHEN ; Qiang LI ; Zuoli LIN
Chinese Journal of Tissue Engineering Research 2025;29(4):707-712
BACKGROUND:How to effectively promote bone regeneration and bone reconstruction after bone injury has always been a key issue in clinical bone repair research.The use of biological and degradable materials loaded with bioactive factors to treat bone defects has excellent application prospects in bone repair. OBJECTIVE:To investigate the effect of polylactic acid-glycolic acid copolymer(PLGA)composite scaffold modified by lysine-grafted graphene oxide nanoparticles(LGA-g-GO)on osteogenic differentiation and new bone formation. METHODS:PLGA was dissolved in dichloromethane and PLGA scaffold was prepared by solvent evaporation method.PLGA/GO composite scaffolds were prepared by dispersing graphene oxide uniformly in PLGA solution.LGA-g-GO nanoparticles were prepared by chemical grafting method,and the PLGA/LGA-g-GO composite scaffolds were constructed by blending LGA-g-GO nanoparticles at different mass ratios(1%,2%,and 3%)with PLGA.The micromorphology,hydrophilicity,and protein adsorption capacity of scaffolds of five groups were characterized.MC3T3 cells were inoculated on the surface of scaffolds of five groups to detect cell proliferation and osteogenic differentiation. RESULTS AND CONCLUSION:(1)The surface of PLGA scaffolds was smooth and flat under scanning electron microscope,while the surface of the other four scaffolds was rough.The surface roughness of the composite scaffolds increased with the increase of the addition of LGA-g-GO nanoparticles.The water contact angle of PLGA/LGA-g-GO(3%)composite scaffolds was lower than that of the other four groups(P<0.05).The protein adsorption capacity of PLGA/LGA-g-GO(1%,2%,and 3%)composite scaffolds was stronger than PLGA and PLGA/GO scaffolds(P<0.05).(2)CCK-8 assay showed that PLGA/LGA-g-GO(2%,3%)composite scaffold could promote the proliferation of MC3T3 cells.Alkaline phosphatase staining and alizarin red staining showed that the cell alkaline phosphatase activity in PLGA/LGA-g-GO(2%,3%)group was higher than that in the other three groups(P<0.05).The calcium deposition in the PLGA/GO and PLGA/LGA-g-GO(1%,2%,and 3%)groups was higher than that in the PLGA group(P<0.05).(3)In summary,PLGA/LGA-g-GO composite scaffold can promote the proliferation and osteogenic differentiation of osteoblasts,and is conducive to bone regeneration and bone reconstruction after bone injury.
8.Discriminating Tumor Deposits From Metastatic Lymph Nodes in Rectal Cancer: A Pilot Study Utilizing Dynamic Contrast-Enhanced MRI
Xue-han WU ; Yu-tao QUE ; Xin-yue YANG ; Zi-qiang WEN ; Yu-ru MA ; Zhi-wen ZHANG ; Quan-meng LIU ; Wen-jie FAN ; Li DING ; Yue-jiao LANG ; Yun-zhu WU ; Jian-peng YUAN ; Shen-ping YU ; Yi-yan LIU ; Yan CHEN
Korean Journal of Radiology 2025;26(5):400-410
Objective:
To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer.
Materials and Methods:
A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs.
Results:
All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027).
Conclusion
The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.
9.Discriminating Tumor Deposits From Metastatic Lymph Nodes in Rectal Cancer: A Pilot Study Utilizing Dynamic Contrast-Enhanced MRI
Xue-han WU ; Yu-tao QUE ; Xin-yue YANG ; Zi-qiang WEN ; Yu-ru MA ; Zhi-wen ZHANG ; Quan-meng LIU ; Wen-jie FAN ; Li DING ; Yue-jiao LANG ; Yun-zhu WU ; Jian-peng YUAN ; Shen-ping YU ; Yi-yan LIU ; Yan CHEN
Korean Journal of Radiology 2025;26(5):400-410
Objective:
To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer.
Materials and Methods:
A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs.
Results:
All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027).
Conclusion
The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.
10.Structural and Spatial Analysis of The Recognition Relationship Between Influenza A Virus Neuraminidase Antigenic Epitopes and Antibodies
Zheng ZHU ; Zheng-Shan CHEN ; Guan-Ying ZHANG ; Ting FANG ; Pu FAN ; Lei BI ; Yue CUI ; Ze-Ya LI ; Chun-Yi SU ; Xiang-Yang CHI ; Chang-Ming YU
Progress in Biochemistry and Biophysics 2025;52(4):957-969
ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.


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