1.A Computational Perspective on Differences Between MHC-I and MHC-II in TCR-pMHC Structure Prediction Resources: Review and Benchmarking
Xiao-Qin WU ; Da-Wei LIU ; Bin-Yu LI ; Yang LIU ; Yang CAO ; Wen-Tao DAI
Progress in Biochemistry and Biophysics 2026;53(5):1376-1399
The initiation of adaptive immune responses relies on the precise recognition and interpretation of antigenic information. In this process, the specific binding of T cell receptors (TCRs) to peptide-major histocompatibility complex (pMHC) molecules represents one of the key molecular events in the initiation of adaptive immune responses. Accordingly, the structural features of TCR-pMHC complexes provide a fundamental basis for dissecting antigen recognition mechanisms and support rational vaccine design, therapeutic target discovery in TCR-based immunotherapy, and TCR identification and optimization. However, experimental determination of TCR-pMHC structures remains costly, time-consuming, and limited in coverage, making computational approaches essential for rapidly obtaining reliable structural information. Computational methods for predicting the structures of TCR-pMHC complexes have advanced rapidly in recent years, driven by progress in deep learning-based modeling frameworks and the increasing availability of structural and sequence resources. Despite these developments, most existing tools do not adequately distinguish the key structural and biophysical differences between MHC class I (MHC-I) and MHC class II (MHC-II) complexes during model construction. As a consequence, their predictive performance differs substantially between class I and class II complexes. In general, structural predictions for class I complexes outperform those for class II complexes. This discrepancy may be related to several fundamental differences between the two systems, including the architecture of the peptide-binding groove, the distribution of peptide lengths, and the properties of peptide flanking residues (PFRs). Compared with MHC-I molecules, MHC-II molecules usually bind longer antigenic peptides, which typically range from 13 to 25 amino acids in length. PFRs at both termini of these peptides participate in regulating the overall conformation of TCR-pMHC class II complexes and exert a pronounced effect on the geometric and physicochemical characteristics of the TCR-pMHC binding interface. Furthermore, within the TCR recognition interface, the complementarity-determining regions (CDRs) consist of segments that differ markedly in conformational behavior. They commonly include regions that are relatively rigid and structurally stable, together with highly flexible segments exhibiting substantial conformational plasticity. These rigidity-flexibility features constitute an essential structural basis enabling TCRs to recognize diverse peptide-MHC ligands and to accommodate conformational heterogeneity at the interface. However, many current modeling tools, in an effort to enforce global conformational stability or reduce structural noise, tend to over-constrain intrinsically flexible regions. Such oversimplification may lead to inappropriate rigidification of flexible CDR loops, resulting in local structural distortions, compromised interface geometry, or even complete modeling failure for specific complexes. Against this background, the review approaches the field from the perspective of computational differences between MHC-I and MHC-II complexes. We first systematically organize and summarize available resources related to TCRs and pMHCs, including structural datasets, sequence databases, prediction tools, and benchmarking studies. We then focus on five representative tools capable of predicting both class I and class II complexes—AlphaFold2, AlphaFold3, TCRmodel2, tFold-TCR, and TCR-pHLA_ModellerS. After excluding structures present in the training sets of these tools, we constructed a benchmark dataset comprising 25 class I and 10 class II TCR-pMHC complexes in the bound state and conducted a systematic evaluation using this dataset. We first employ widely used general evaluation metrics, including All-Atom Root Mean Square Deviation (All-Atom RMSD), Backbone RMSD, Template Modeling score (TM-score), and DockQ, to assess the global conformational accuracy and interface modeling quality of class I and class II complexes. For class II complexes, we propose for the first time a peptide flanking residue deviation index, including the PFRs-Deviation Index (PFRs-DI), N-PFR-Deviation Index (N-PFR-DI), and C-PFR-Deviation Index (C-PFR-DI), to quantitatively characterize conformational deviations in PFRs. In addition, we propose the CDR conformational consistency index (CCC) designed to qualitatively evaluate the ability of prediction tools to capture TCR CDR conformational flexibility. These metrics collectively assess a tool’s ability to model both overall conformation and critical functional regions, thereby addressing the limitations of existing evaluation criteria that overemphasize global structure while inadequately capturing modeling quality in key functional areas. This establishes a unified analytical framework for MHC-I and MHC-II complexes to guide data resource selection, modeling strategy formulation, and evaluation system development. The framework further advances computational modeling and provides crucial support for multi-scale analysis of TCR-pMHC recognition mechanisms and their biological functions.
2.A Computational Perspective on Differences Between MHC-I and MHC-II in TCR-pMHC Structure Prediction Resources: Review and Benchmarking
Xiao-Qin WU ; Da-Wei LIU ; Bin-Yu LI ; Yang LIU ; Yang CAO ; Wen-Tao DAI
Progress in Biochemistry and Biophysics 2026;53(5):1376-1399
The initiation of adaptive immune responses relies on the precise recognition and interpretation of antigenic information. In this process, the specific binding of T cell receptors (TCRs) to peptide-major histocompatibility complex (pMHC) molecules represents one of the key molecular events in the initiation of adaptive immune responses. Accordingly, the structural features of TCR-pMHC complexes provide a fundamental basis for dissecting antigen recognition mechanisms and support rational vaccine design, therapeutic target discovery in TCR-based immunotherapy, and TCR identification and optimization. However, experimental determination of TCR-pMHC structures remains costly, time-consuming, and limited in coverage, making computational approaches essential for rapidly obtaining reliable structural information. Computational methods for predicting the structures of TCR-pMHC complexes have advanced rapidly in recent years, driven by progress in deep learning-based modeling frameworks and the increasing availability of structural and sequence resources. Despite these developments, most existing tools do not adequately distinguish the key structural and biophysical differences between MHC class I (MHC-I) and MHC class II (MHC-II) complexes during model construction. As a consequence, their predictive performance differs substantially between class I and class II complexes. In general, structural predictions for class I complexes outperform those for class II complexes. This discrepancy may be related to several fundamental differences between the two systems, including the architecture of the peptide-binding groove, the distribution of peptide lengths, and the properties of peptide flanking residues (PFRs). Compared with MHC-I molecules, MHC-II molecules usually bind longer antigenic peptides, which typically range from 13 to 25 amino acids in length. PFRs at both termini of these peptides participate in regulating the overall conformation of TCR-pMHC class II complexes and exert a pronounced effect on the geometric and physicochemical characteristics of the TCR-pMHC binding interface. Furthermore, within the TCR recognition interface, the complementarity-determining regions (CDRs) consist of segments that differ markedly in conformational behavior. They commonly include regions that are relatively rigid and structurally stable, together with highly flexible segments exhibiting substantial conformational plasticity. These rigidity-flexibility features constitute an essential structural basis enabling TCRs to recognize diverse peptide-MHC ligands and to accommodate conformational heterogeneity at the interface. However, many current modeling tools, in an effort to enforce global conformational stability or reduce structural noise, tend to over-constrain intrinsically flexible regions. Such oversimplification may lead to inappropriate rigidification of flexible CDR loops, resulting in local structural distortions, compromised interface geometry, or even complete modeling failure for specific complexes. Against this background, the review approaches the field from the perspective of computational differences between MHC-I and MHC-II complexes. We first systematically organize and summarize available resources related to TCRs and pMHCs, including structural datasets, sequence databases, prediction tools, and benchmarking studies. We then focus on five representative tools capable of predicting both class I and class II complexes—AlphaFold2, AlphaFold3, TCRmodel2, tFold-TCR, and TCR-pHLA_ModellerS. After excluding structures present in the training sets of these tools, we constructed a benchmark dataset comprising 25 class I and 10 class II TCR-pMHC complexes in the bound state and conducted a systematic evaluation using this dataset. We first employ widely used general evaluation metrics, including All-Atom Root Mean Square Deviation (All-Atom RMSD), Backbone RMSD, Template Modeling score (TM-score), and DockQ, to assess the global conformational accuracy and interface modeling quality of class I and class II complexes. For class II complexes, we propose for the first time a peptide flanking residue deviation index, including the PFRs-Deviation Index (PFRs-DI), N-PFR-Deviation Index (N-PFR-DI), and C-PFR-Deviation Index (C-PFR-DI), to quantitatively characterize conformational deviations in PFRs. In addition, we propose the CDR conformational consistency index (CCC) designed to qualitatively evaluate the ability of prediction tools to capture TCR CDR conformational flexibility. These metrics collectively assess a tool’s ability to model both overall conformation and critical functional regions, thereby addressing the limitations of existing evaluation criteria that overemphasize global structure while inadequately capturing modeling quality in key functional areas. This establishes a unified analytical framework for MHC-I and MHC-II complexes to guide data resource selection, modeling strategy formulation, and evaluation system development. The framework further advances computational modeling and provides crucial support for multi-scale analysis of TCR-pMHC recognition mechanisms and their biological functions.
3.Comparative analysis of the characteristics of imported malaria cases in Nanning City in 2024 and the same period of the previous year
Shu-lin WEI ; Zhi-qiang QU ; Yuan-yuan LUO ; Yan-cui HUANG ; Shu-qin DIAO ; Xue LI ; Sheng-long YANG ; Xiao-yu HUANG ; Mi-fang LUO
Acta Parasitologica et Medica Entomologica Sinica 2026;33(2):81-84
Objective To investigate the epidemiological characteristics of malaria and provide a basis for developing improved prevention and control measures. Methods Data were obtained from the Chinese Disease Prevention and Control Information System. Malaria surveillance data for Nanning City from January 1,2023, to December 31,2024, were exported from the Infectious Disease Reporting Information Management Subsystem. The characteristics of the two groups of malaria cases were compared. Results A total of 103 imported malaria cases were reported in Nanning City in 2024, representing a 38.32% decrease compared with the same period of the previous year. No statistically significant difference were observed between cases reported in 2023 and 2024 in terms of average age, gender ratio, proportion of parasite species, and monthly reporting distribution;however, statistically significant differences were found in the proportion of reporting areas and current residence areas(χ2= 13.572 and 10.355, respectively; P = 0.001 and 0.035, respectively). The proportion of cases reported in Shanglin County and the proportion of cases residing in Shanglin County were both lower than those during the same period of the previous year. Conclusions The high aggregation of imported malaria cases in Nanning City has decreased. Medical institutions in areas other than Shanglin County should strengthen their vigilance against malaria.
4.Design of integrated device for cleaning,sterilizing and drying glass graduated pipette
Xiao-hong ZHU ; Xiao-qin HA ; Cheng-yu WANG
Chinese Medical Equipment Journal 2025;46(4):108-112
Objective To design an integrated device for cleaning,sterilizing and drying the glass graduated pipette with considerations on its characteristics.Methods The integrated device had its shell made of 304 stainless steel and hardware part composed of three modules for control,cleaning and drying.The control module consisted of a human machine interface(HMI)touch screen,a programmable logic controller(PLC),solenoid valves and etc;the cleaning module was made up of an ultrasonic release disk,a heat preservation cylinder,a bracket and etc;the drying module comprised a blower,a heating plate,a heat preservation cylinder and connected pipes.The HMI was developed with the programming language of EasyBuilder,and the PLC control logic was written with SCL high-level programming language.Results The device developed could be used for cleaning,sterilizing and drying the glass graduated pipette,and the pipette could be stored in the device after drying.Conclusion The integrated device developed eliminates manual operation and enhances the efficiency of the cleaning,sterilization and drying of the glass graduated pipette.[Chinese Medical Equipment Journal,2025,46(4):108-112]
5.The protective effect of Gualou Guizhi granules on neuronal injury induced by LPS-activated microglia based on Notch signaling pathway
Xue-zhen LI ; Xiao-xue ZOU ; Wen-ting CHEN ; Yi FENG ; Ya-nan LI ; Yu-qin ZHANG ; Li-hong NAN
Chinese Pharmacological Bulletin 2025;41(4):781-786
Aim To investigate the protective effect of Gualou Guizhi granules(GLGZG)on neuronal injury induced by LPS-activated microglia based on Notch signaling pathway.Methods LPS-activated microglia were co-cultured with neurons to construct neuron inju-ry models,and the cells were divided into the control group,model group,Notch inhibitor(DAPT)group,GLGZG(50,100,200 mg·L-1)group,DAPT+100 mg·L-1GLGZG group.After intervention,the activity of HT22 cells was detected by CCK-8 method,and rel-ative mRNA expression was detected by real-time PCR.The relative protein expression was detected by Western blot.Results Compared with the model group,after GLGZG intervention,the cell activity was significantly improved,GLGZG decreased IL-6,IL-12,Bax,Notch 1,caspase-3,Delta-1,NICD,RBPSUH,HES1 expression,and increased Bcl-2 expression(P<0.05).Compared with the model group,the NICD,RBPSUH and HES1 mRNA and protein expressions significantly decreased after DAPT treatment(P<0.05),and there was no superposition effect with GLG-ZG.Conclusion GLGZG may play a neuroprotective role by inhibiting inflammatory factors and apoptosis,and inhibiting Notch signaling pathway.
6.Ameliorative effects of Compound Fufangteng Mixture on cyclophosphamide-induced immunosuppression in mice
Li-na LIU ; Yu-fang SHEN ; Qin-qin WANG ; Lin-yu XIAO ; Jing-yu LIU ; Jun-ni MO ; Ren-yi-kun YUAN ; Hong-wei GAO ; Jian XIAO
Chinese Traditional Patent Medicine 2025;47(10):3249-3256
AIM To investigate the ameliorative effects of Compound Fufangteng Mixture(CFM)on cyclophosphamide(CTX)-induced immunosuppression in mice.METHODS Forty-eight male C57BL/6J mice were randomly divided into the blank control group,the model group,the levamisole hydrochloride group(40 mg/kg)and the low-dose,medium-dose and high-dose CFM groups(3.75,7.5,10 g/kg),with 8 mice in each group,and given respective intervention orally once daily for 14 days.On the 5th to 7th day of administration,with the blank control group given normal saline intraperitoneally,the other groups underwent intraperitoneal CTX injections(80 mg/kg).24 hours after the last administration,organ indices of thymus and spleen were calculated;splenic histopathological alterations were assessed by HE staining;serum levels of IL-2,IL-6 and IgG were quantified using ELISA;splenic CD4+,CD8+T lymphocytes,alongside CD86+and CD206+macrophages populations were analyzed by flow cytometry;and splenic expression of CD4,CD8 and F4/80 was evaluated by immunohistochemical staining.RESULTS In CTX-treated mice,CFM administration mitigated body weight loss;enhanced thymus weight and thymic index;ameliorated splenic immune cell populations,elevated serum levels of cytokines IL-2,IL-6 and IgG in serum;and upregulated splenic levels of CD45+CD3+T lymphocytes and F4/80+CD11b+macrophages,alongside increasing the expression of CD4,CD8 and F4/80 surface markers.CONCLUSION CFM alleviates CTX-induced immunosuppression state in mice by modulating immune cells,restoring immune function and enhancing anti-inflammatory and tissue repair capabilities.
7.Relationship between autonomous rehabilitation behavior and related symptoms of middle-aged stroke patients
Yuting TAN ; Zhixia ZHANG ; Mengli XU ; Peiran GUO ; Qin XIAO ; Linru QIAO ; Feiyun SONG ; Qiaojun YU
Chinese Journal of Nursing 2025;60(7):773-778
Objective To explore the time-varying characteristics and correlation degree of autonomous rehabili-tation behavior and related symptoms of middle-aged stroke patients,and to provide a basis for clinical transitional nursing and precise rehabilitation.Methods Ecological momentary assessment was used to select 57 middle-aged stroke patients who underwent rehabilitation treatment in the Rehabilitation Medicine Department of a tertiary com-prehensive hospital in Wuhan from March 15 to August 30,2024,using convenience sampling method.Their au-tonomous rehabilitation behavior and related symptoms(fatigue,pain,emotion,sensation)were continuously monitored for 2 weeks.A hierarchical linear model was used to analyze the correlation between behavior and symptoms.Results The autonomous rehabilitation behavior of middle-aged stroke patients showed a fluctuating increasing trend,and the symptom score showed a slow decreasing trend.The hierarchical linear model showed that compared with female patients,male patients have longer duration of autonomous rehabilitation behavior(P<0.05).The number and duration of autonomous rehabilitation behaviors in patients without fatigue were higher(P<0.05).The number of autonomous rehabilitation behaviors in patients without pain was higher than that in patients with pain(P<0.05).The number of autonomous rehabilitation behavior items among patients who perceived more pleasure in rehabilitation was higher than that among patients with greater difficulty in rehabilitation challenges(P<0.05).Patients with high rehabilitation confidence have higher numbers and duration of autonomous rehabilitation behaviors compared to pa-tients with low rehabilitation confidence(P<0.05).Conclusion There are significant individual differences and dy-namic changes in the autonomous rehabilitation behavior and related symptoms of middle-aged stroke patients.Nurs-ing staff should accurately implement personalized rehabilitation services during the transition period,enhance pa-tients'autonomy and self-management ability in home-based rehabilitation,in order to improve the overall rehabilita-tion effect.
8.Clinical and pathological features and prognostic analysis of early-onset intrahepatic cholangiocarcinoma
Delong QIN ; Yue TANG ; Zonglong LI ; Jialu CHEN ; Zhimin GENG ; Chuandong SUN ; Hong WU ; Yinghe QIU ; Tianqiang SONG ; Xianhai MAO ; Yu HE ; Zhangjun CHENG ; Wenlong ZHAI ; Jingdong LI ; Xiao LIANG ; Ruixin LIN ; Di TANG ; Zhaohui TANG ; Zhiwei QUAN
Chinese Journal of Surgery 2025;63(6):500-507
Objective:To explore the clinical and pathological features and survival outcomes of patients with early-onset intrahepatic cholangiocarcinoma (EOICC).Methods:This is a multicenter, retrospective cohort study. Data of 1 160 intrahepatic cholangiocarcinoma patients undergoing radical resection in 14 tertiary Grade A hospitals in China from January 2010 to November 2021 were retrospectively collected. The cohort included 632 males and 528 females, aged( M (IQR)) 61 (14) years (range: 22 to 93 years). ICC aged ≤50 years at the time of diagnosis was defined as EOICC and >50 years as late-onset intrahepatic cholangiocarcinoma (LOICC). Of these, there were 247 cases in the EOICC group and 913 cases in the LOICC. The clinical and pathological characteristics of both groups were analyzed and compared using the independent sample t-test, Mann-Whitney U test or Kaplan-Meier method. Univariate and multivariate Cox regression models for patient outcomes were constructed and forest graphed. Results:Compared with the patients in the LOICC group, patients in the EOICC group had lower carcinoembryonic antigen levels (2.5(4.0) μg/L vs. 3.1(5.2)μg/L, U=124 899, P=0.009) and CA19-9 level (63.4(524.7)U/ml vs. 77.9(611.3)U/ml, U=120 320, P=0.013), higher levels of ALT (29(35)U/L vs. 24(26)U/L, U=101 214, P=0.013), a lower score of the Eastern US Cooperative Oncology Group (0 score patients: 54.7% vs. 44.1%, χ2=12.472, P=0.014), higher TNM stage ( χ2=11.807, P=0.038), and proportion of lymph node dissection (62.3% vs. 54.1%, χ2=5.355, P=0.021). Patients in the two groups in sex, first diagnosis symptoms, intrahepatic bile duct stone history, nail protein, albumin, total bilirubin, transaminase, liver function Child-Pugh grade, T stage, stage, N stage, preoperative laparoscopic exploration proportion, tumor diameter, vascular invasion proportion, differentiation, margin, intraoperative bleeding, postoperative complications, postoperative hospital days were no statistical significance (all P>0.05). Patients in the EOICC group had better outcomes than the LOICC group (median survival time: 29.7 months vs. 25.0 months, 3-year overall survival: 45.1% vs. 37.8%, P=0.027). Conclusion:EOICC patients are better than LOICC patients in carcinoembryonic antigen, CA19-9, ALT, physical strength status and TNM stage, and the long-term prognosis is also better than LOICC patients.
9.Establishment and application of a method for detecting Toxoplasma gondii based on recombinant polymerase amplification technology
Shao-zheng SONG ; Le-ying GU ; Ying-chao WU ; Ya-qin MENG ; Kang-ying YU ; Xiao-hua HUANG
Chinese Journal of Zoonoses 2025;41(2):107-112
To establish a method for detecting Toxoplasma gondii based on recombinant polymerase amplification(RPA)technology and apply it to clinical sample validation of pet cats.Using the 529 repeat sequence of the Toxoplasma gondii gene as the target gene sequence,primers and probes were designed,and the Rep-529 recombinant plasmid was constructed as the standard.A fluorescent RPA reaction system was established.Dilute the plasmid standard 10 times to different concentrations as the detection template for sensitivity testing;Specific testing was conducted using genomic DNA from several parasitic spe-cies,including Toxoplasma gondii,Cryptosporidium,Neosporidium,Trichinella spiralis,Giardia flagellata,Babesia bo-vis and Theileria annulata as templates;Simultaneously,fluorescence RPA and RT-PCR were used to detect 52 positive and 40 negative cats clinical samples,and the coincidence rate of the detection results of the two methods were compared and ana-lyzed.The RPA reaction system was successfully established using PTRep recombinant plasmid as the standard,ToxD-F/ToxD-R as the primer,and RepD-P as the fluorescent probe.The reaction temperature was constant at 39 ℃,the reaction time was 30 minutes,and the detection sensitivity was 1 copy/μL.There is no significant cross reaction with parasites such as Cryptosporidium,Neosporidium,Trichinella spiralis,Giardia,Babesia bovis and Theileria annulata,and the specificity is good.A total of 92 clinical fecal samples from cats were tested,and the positive coincidence rate of fluorescence RPA detection method was higher than that of conventional RT-PCR method(98.08%vs.82.69%),and the difference of the positive rate was not statistically significant(X2=1.392,P>0.05).The fluorescence RPA detection method for Toxoplasma gondii suc-cessfully established in this study has the characteristics of being fast,sensitive,specific,accurate,and reliable.It can be used as a rapid clinical detection kit for Toxoplasma gondii in cats and other animals,providing new technical support for the subsequent epidemiological monitoring and precise clinical diagnosis of toxoplasmosis in cats,other animals,and humans in the future.
10.Effect of Asperisochroman B on oxygen glucose deprivation/reoxygenation-induced neuronal damage
Xiao-ting HONG ; Xue-zhen LI ; Han HUANG ; Xiao-xue ZOU ; Yu-qin ZHANG
Chinese Pharmacological Bulletin 2025;41(7):1311-1317
Aim To explore the protective effect of the isochroman compound Asperisochroman B(AB)on oxygen-glucose deprivation/reoxygenation(OGD/R)injury of neurons based on the PI3K/AKT/Foxo1 path-way and to reveal the related mechanism.Methods Primary neurons were cultured and the OGD/R model was constructed.The primary neurons were divided in-to the blank control group,OGD/R group,and AB low,medium,and high concentration(3,10,30 μmol·L-1)groups.The effects of AB on primary neurons were determined by CCK-8 assay,lactate dehydrogen-ase(LDH)release assay,and Hoechst 33342 stai-ning.The expression levels of PI3K,AKT,and Foxo1-related proteins were detected by Western blot.After intervention with the PI3K inhibitor(LY294002)and re-modeling and intervention with high concentra-tion of AB(30 μmol·L-1),the expression of PI3K/Foxo1 pathway-related proteins was detected by West-ern blot.Results Compared with the OGD/R group,AB could significantly increase the cell survival rate of primary neurons and reduce the release of LDH.The results of Hoechst 33342 and immunofluorescence stai-ning showed that AB reduced apoptosis after OGD/R injury.Western blot results showed that compared with the OGD/R group,after AB intervention,the expres-sion levels of Bcl-2 and NeuN proteins in neurons sig-nificantly increased(P<0.01),and the expression level of Bax protein significantly decreased(P<0.01).At the same time,it upregulated the expres-sion levels of p-AKT and PI3K proteins,promoted Foxo1 phosphorylation,and downregulated the expres-sion of Foxo1.Compared with the high-dose AB group,LY294002 could inhibit the changes of the a-bove indicators and reverse the protective effect of AB on OGD/R-injured primary neurons.Conclusions AB can alleviate oxygen-glucose deprivation/reoxygen-ation-induced neuronal injury,and its mechanism may be related to the activation of the PI3K/AKT/Foxo1 signaling pathway.


Result Analysis
Print
Save
E-mail