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.Quantitative Chemical Exchange Saturation Transfer MRI for Diagnosing Thyroid-Associated Ophthalmopathy Activity: A Prospective Feasibility Study
YunMeng WANG ; WeiYi ZHOU ; YuanYuan CUI ; JianKun DAI ; YuXin CHENG ; QingQing WEN ; TianYi XING ; HongBiao SUN ; Song JIANG ; MeiLing XU ; ZhenHuan WANG ; Yan SONG ; Tuo LI ; Yi XIAO
Korean Journal of Radiology 2026;27(2):161-173
Objective:
This prospective study evaluated the feasibility of chemical exchange saturation transfer (CEST) MRI for assessing disease activity in thyroid-associated ophthalmopathy (TAO).
Materials and Methods:
A total of 88 patients with active TAO, 76 with inactive TAO, and 30 healthy controls were enrolled. CEST MRI-derived magnetization transfer ratio (MTR) and MTR asymmetry (MTRasym) at 1 ppm, 2 ppm, and 3.5 ppm were calculated. Clinical data, MTR, and MTRasym values for the extraocular muscles (one representative muscle per eye, yielding two measurements per participant) were compared among the groups. Spearman’s correlation was used to examine associations between imaging parameters and the clinical activity score (CAS) in patients with TAO. Logistic regression analysis was used to identify independent associations between imaging parameters and disease activity in patients with TAO (active vs. inactive). Receiver operating characteristic (ROC) analysis was conducted to evaluate the diagnostic performance for discriminating active from inactive TAO.
Results:
Patients with active TAO showed lower MTR values (P < 0.001) and higher MTRasym (1 ppm), MTRasym (2 ppm), and MTRasym (3.5 ppm) (all P < 0.001) compared with those with inactive TAO. MTR was negatively correlated with CAS (r = -0.402; P < 0.001), while MTRasym (1 ppm), MTRasym (2 ppm), and MTRasym (3.5 ppm) were positively correlated with CAS (r = 0.369, 0.350, and 0.349, respectively;all P < 0.001). MTR and MTRasym (1 ppm) were independently associated with TAO activity. The areas under the ROC curve (AUCs) for MTR and MTRasym (1 ppm) in discriminating active from inactive TAO were 0.772 and 0.730, respectively. Combining MTR with MTRasym (1 ppm) significantly improved diagnostic performance compared with either parameter alone, achieving an AUC of 0.805 (P = 0.029 and 0.001).
Conclusion
MTR and MTRasym (1 ppm) were independently associated with TAO activity. Their combination further enhanced diagnostic performance in distinguishing active from inactive TAO, suggesting their potential as quantitative imaging biomarkers to guide treatment in patients with TAO.
4.Chemical constituents from the sticks and leaves of Croton cascarilloides and their biological activities
Yu-jie LÜ ; Hui-qin CHEN ; Hao WANG ; Jing-zhe YUAN ; Wen-li MEI ; Shou-bai LIU ; Hao-fu DAI
Chinese Traditional Patent Medicine 2025;47(7):2249-2254
AIM To study the chemical constituents from the sticks and leaves of Croton cascarilloides Raeusch.and their biological activities.METHODS The 95%ethanol extract from the sticks and leaves of C.cascarilloides was isolated and purified by MCI,silica gel,Sephadex LH-20 and semi-preparative HPLC,then the structures of obtained compounds were identified by physicochemical properties and spectral data.LPS-induced NO RAW264.7 cell model induced by LPS was used to evaluate its anti-inflammatory activity in vitro.GES-1 injury model induced by taurocholic acid was used to screen the gastric mucosal protection activity.RESULTS Fourteen compounds were isolated and identified as bullatantriol(1),(-)-boscialin(2),(+)-dehydrovomifoliol(3),3-(hydroxylacetyl)-indole(4),pinoresinol(5),3,7-dimethyl-octa-1,7-diene-3,6-ol(6),(+)-syringaresinol(7),curcasinlignan B(8),cleomiscosin C(9),cleomiscosinD(10),2,6-dimethyl-octa-1,7-dien-3,6-diol(11),vanillin(12),vanillic acid(13),methyl vanillate(14).Compound 4 had certain anti-inflammatory activity,with IC50 values of 73.62 μmol/L.The protective rates of 25 μmol/L compounds 1-4,6,9-12 and 14 on gastric mucosal epithelial cells were 30.07%,34.18%,23.91%,30.92%,17.51%,19.69%,31.76%,22.46%,30.56%and 14.49%,respectively.CONCLUSION Compounds 1-14 are isolated from this plant for the first time.Compound 4 shows anti-inflammatory activity,1-4,6,9-12 and 14 show different degrees of gastric mucosal epithelial cell protective activity.
5.Evaluation of chemical constituent consistency in formula granules and traditional decoctions of Gouteng Jiangya Formula
Qing-gang ZHANG ; Dai-liang ZHANG ; Hong QI ; Shu-wen DING ; Yu-zhuo WANG ; Yun-lun LI ; Ji-fu HE ; Huan-ying GUO ; Gui-yun CAO ; Zhao-qing MENG
Chinese Traditional Patent Medicine 2025;47(11):3555-3565
AIM To evaluate the chemical constituent consistency in formula granules and traditional decoctions of Gouteng Jiangya Formula.METHODS HPLC characteristic chromatograms were established,the analysis was performed on a 30 ℃ thermostatic YMC-Triart C18 column(4.6 mm× 250 mm,5 μm),with the mobile phase comprising of acetonitrile-0.2%phosphoric acid flowing at 1.0 mL/min in a gradient elution manner,and the detection wavelength was set at 240 nm.Puerarin was used as an internal standard to calculate the relative correction factors of 3'-methoxy puerarin,puerarin apioside,magnolflorine,paeoniflora,daidzin,baicalin,palmatine,berberine,wogonoside and benzoylpaeoniflorin,after which the content detemination was made by quantitative analysis of multi-components by single-marker(QAMS).RESULTS The characteristic chromatograms of 9 batches of formula granules and 15 bacthes of traditional decoctions demonstrated the similarities of more than 0.90 at the detection wavelengths of 192,210,240,260,280,300,320,360 nm,along with similar total peak areas.Eleven constituents showed good linear relationships within their own ranges(r>0.999 0),whose average recoveries were 97.27%-101.64%with the RSDs of 0.36%-1.11%,the result obtained by QAMS and external standard method demonstrated no significant differences(P>0.05).The contents of various constituents in the formula granules approximated those in the traditional decoctions.CONCLUSION The consistent kinds and contents of various constituents are obversable in formula granules and traditional decoctions of Gouteng Jiangya Formula,which can provide a reference for the reasonable clinical application of this formula.
6.Effect of sodium cantharidinate and vitamin B6 injection on human hepatocellular carcinoma cells and its mechanism
Lan-Lan SI ; Wen XU ; Le LI ; Dong JI ; Xue-Yuan CHEN ; Jiu-Zeng DAI ; Zeng-Tao YAO ; Wei-Wei CHEN ; Yan LIU
Medical Journal of Chinese People's Liberation Army 2025;50(6):747-755
Objective To analyze the effect of sodium cantharidinate and vitamin B6 injection(SCV)on four human hepatocellular carcinoma(HCC)cell lines(SMMC-7721,Bel-7402,Huh7,and HepG2)and explore its mechanism.Methods Normal hepatic cell line L02 was treated with SCV at concentrations of 0 μmol/L(control),0.5,1,2,4,8,16,and 32 μmol/L,and the cytotoxicity of SCV on L02 cells was detected using CCK-8 assay.Human HCC cell lines(SMMC-7721,Bel-7402,Huh7,and HepG2)were cultured.SCV-untreated control group(0 μmol/L)and 2,4,and 8 μmol/L SCV-treated groups were set up.CCK-8 assay,plate cloning formation assay,Transwell assay,wound healing assay,and flow cytometry were used to detect the effects of SCV on the growth and proliferation capacity,colony formation ability,invasion and migration capabilities,cell cycle,and apoptosis of the four hepatocellular carcinoma cell lines,respectively.Western blotting was performed to detect the expression levels of apoptosis-related proteins,including nuclear factor kappa-B subunit p65(p65),B-cell lymphoma 2(Bcl-2),and Caspase-3,and to preliminarily explore the underlying mechanism.Results The CCK-8 assay showed that SCV at 0.5,1,2,4,and 8 μmol/L had no significant cytotoxic effect on L02 cells compared with untreated control group,so 2,4,and 8 μmol/L SCV were selected for subsequent experiments.Compared with the untreated control group(0 μmol/L),SCV at different concentrations(2,4,and 8 μmol/L)significantly inhibited the proliferation of the four HCC cell lines(P<0.001).The plate cloning formation assay showed that SCV at different concentrations(2,4,and 8 μmol/L)significantly reduced the colony formation ability of the four HCC cell lines(P<0.05 or P<0.01 or P<0.001).In addition,Transwell and wound healing assays revealed that SCV at different concentrations(2,4,and 8 μmol/L)significantly inhibited the invasion and migration of HCC cells(P<0.05 or P<0.01 or P<0.001).In the above results,the inhibitory effect of SCV was concentration-dependent.Flow cytometry analysis indicated that SCV arrested cells in the G2/M phase(P<0.05 or P<0.01 or P<0.001)and significantly promoted cell apoptosis(P<0.05 or P<0.01 or P<0.001).Western blotting showed that SCV significantly down-regulated the expression of p65(P<0.05 or P<0.01)and Bcl-2(P<0.05),and up-regulated the expression of Caspase-3(P<0.05 or P<0.01).Conclusions SCV can significantly inhibit the proliferation,colony formation,invasion,and migration of multiple human HCC cell lines and arrest the cell cycle.SCV may inhibit the expression of p65 and Bcl-2,thereby lifting their inhibitory effect on the apoptotic pathway and activating Caspase-3 to promote apoptosis.
7.Advances in the application of dual-task training in older adults with cognitive frailty
Chunhao DAI ; Wen LI ; Teng YANG ; Minmin LENG ; Luyao YAN ; Ziting XU ; Haoyuan LI ; Lijuan YANG
Chinese Journal of Modern Nursing 2025;31(28):3915-3920
Cognitive frailty, a novel concept in geriatric medicine, has become a focal point of recent research. Dual-task training, which innovatively integrates physical activity with cognitive rehabilitation, has shown promise in simultaneously enhancing motor function and cognitive performance in older adults with cognitive frailty. This review summarizes the concept of dual-task training, its application modalities, and its effectiveness in this population. It also proposes strategies for further implementation, aiming to provide a reference for future research and practical applications of dual-task training in cognitively frail older adults.
8.Therapeutic effect of pressing needle therapy on nausea and vomiting in patients after gynecological laparoscopic surgery
Miao-miao MA ; Li-jun DAI ; Ting XU ; Dan LIU ; Jing-wen CHEN
Fudan University Journal of Medical Sciences 2025;52(1):114-118
Objective To observe the clinical effect of pressing needle in preventing and reducing nausea and vomiting in patients after gynecological laparoscopic surgery.Methods A total of 199 patients undergoing gynecological laparoscopic surgery from May to Nov 2023 at Obstetrics and Gynecology Hospital,Fudan University were randomly divided into research group(n=99)and control group(n=100).The observation group was given Tanzhong,zanzhu and Taichong pressing needles on the basis of the control group.The postoperative nausea and vomiting were observed in the two groups.Results There were significant differences in the incidence and duration of postoperative nausea,the incidence of postoperative vomiting between the two groups(P<0.05),but there was no significant difference in the duration of postoperative vomiting.The incidence of nausea and vomiting in the observation group was lower than that in the control group.Conclusion Pressing needle can effectively prevent the occurrence of nausea and vomiting after gynecological laparoscopic surgery,and reduce the degree of nausea and vomiting,and reduce the duration of nausea.
9.Expression of TRIM24 protein in human clear cell renal cell carcinoma tissue and its clinical significance
Haiying GENG ; Yan YU ; Chunmei DAI ; Youfeng WEN ; Ning LI
Journal of Jilin University(Medicine Edition) 2025;51(2):486-492
Objective:To discuss the expression of tripartite motif-containing protein 24(TRIM24)in the clear cell renal cell carcinoma(ccRCC)tissue,and to clarify its relationships with the clinicopathological features and prognosis of the ccRCC patients.Methods:The cancer and paracancer normal tissues were collected from 90 ccRCC patients who had not undergone preoperative radiotherapy or chemotherapy.Tissue microarray and immunohistochemistry were used to detect the expression levels of TRIM24 protein in ccRCC tissue.The differences in TRIM24 protein expression between ccRCC and paracancer normal tissues were analyzed.The score of TRIM24 protein expression and the average value were calculated,and based on the average value,the patients were classified into TRIM24 protein low-expression and TRIM24 protein high-expression groups.The associations between the TRIM24 protein expression and different clinicopathological features of the patients were analyzed,and the relationship between the TRIM24 protein expression and the prognosis of the patients was analyzed.Results:The immunohistochemistry results showed that the TRIM24 protein was expressed in both the nucleus and cytoplasm of the ccRCC tumor cells,and there were significant differences in the TRIM24 protein expression level in ccRCC tissue when compared with paracancer normal tissue(P<0.05).The TRIM24 protein expression in the nucleus of ccRCC tissue was associated with the patient's age,gender,and tumor size(P<0.05).The Kaplan-Meier survival analysis results showed that the overall survivals of the patients with high TRIM24 protein expression in the cytoplasm of ccRCC tissue,older age,and higher pathological grade were shorter than those with low TRIM24 protein expression,younger age,and lower pathological grade(P<0.05).The multivariate Cox regression analysis results showed that the prognosis of the patients with high TRIM24 protein expression in the cytoplasm and higher pathological grade were poorer compared with the patients with low TRIM24 protein expression and lower pathological grade(P<0.05).Conclusion:The ccRCC patients with high TRIM24 expression in the cytoplasm of ccRCC tumor tissue and higher pathological grade have the lower postoperative survival rates and poorer prognosis.
10.Study on the accuracy of azimuthal sound source localization and the effect of different azimuth directions and angular interval settings
Jinsheng DAI ; Xiaolin HE ; Jiaying LI ; Xing WANG ; Xiaohui WEN ; Ningyu WANG ; Juan ZHANG
Chinese Archives of Otolaryngology-Head and Neck Surgery 2025;32(2):82-85,93
OBJECTIVE To investigate the relationship between azimuth direction,angular intervals,and the accuracy of azimuthal sound source localization.METHODS Fifteen young subjects with normal hearing were tested using nine azimuth settings.The test results were presented as root mean square error and percentage confusion.RESULTS The confusion rate under high-frequency narrowband noise was significantly higher than that under broadband noise and three-syllable words.In the frontal direction,statistically significant differences were observed between the 20° and 10° intervals,as well as between the 20° and 15° intervals(P<0.05),but no significant difference was found between the 10° and 15° intervals(P>0.05).In the lateral and rear directions,statistically significant differences were found between the 30° and 15° intervals,as well as between the 30° and 20° intervals(P<0.05),but no significant difference was found between the 15° and 20° intervals(P>0.05).Statistically significant differences were observed between the frontal direction and both the lateral and rear directions(P<0.05),but no significant difference was found between the lateral and rear directions(P>0.05).CONCLUSION Using stimuli that contain broader bandwidth cues can more accurately reflect the subject's horizontal localization ability.For source azimuth identification tests using broadband noise and three-syllable words,it is recommended to use a 15° interval in the frontal direction,and a 20° interval in the lateral and rear directions.The frontal and lateral directions can be preferred for testing.

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