1.Mass Spectrometry-based Antibody Sequencing Technologies
Sheng-Mei LIU ; Peng XUE ; Xiao-Jian WANG
Progress in Biochemistry and Biophysics 2026;53(4):840-854
Antibodies play a critical role in adaptive immune responses and serve as key components in disease diagnosis and treatment. These molecules exhibit dynamic post-translational modifications (PTMs), such as glycosylation and phosphorylation, which regulate their effector functions. To date, nearly all of our knowledge about antibody repertoires has come from B cell receptor (BCR) sequencing (BCR-seq), which facilitates the profiling of clonal composition and the tracing of maturation trajectories within B-cell repertoires. However, circulating antibodies found in bodily fluids—such as serum, saliva, milk, mucosal secretions, and cerebrospinal fluid—exhibit diversities and specificities beyond what BCR-seq alone can predict. Therefore, identifying and quantifying antibody clonotypes at the protein level could enhance diagnosis, prognosis, and treatment strategies in personalized medicine. The critical gap between genotype and phenotype necessitates complementary methodologies that enable the direct characterization of antibody proteins in their native functional states. Mass spectrometry (MS)-based antibody repertoire sequencing (Ab-seq) is currently the only feasible approach for this task and primarily includes database-dependent methods—such as bottom-up, middle-down, and top-down approaches—as well as database-independent de novo sequencing technology. These strategies enable multi-level, high-precision characterization ranging from peptides and domains to intact antibody molecules. Unlike the shotgun strategy commonly used in routine proteomics, obtaining full sequences of all antibodies presents unique challenges. It requires specialized methodological adaptations to address issues related to dynamic range, sequence variation, and sample complexity. This review introduces the technical principles, methodological workflows, and recent applications of various mass spectrometry-based antibody repertoire sequencing (Ab-seq) strategies, with a focus on approaches designed to improve sequence coverage and identification accuracy. These include multi-enzyme digestion, hybrid fragmentation methods, and artificial intelligence-assisted de novo sequencing. By systematically comparing database-dependent techniques—such as bottom-up, middle-down, and top-down approaches—with database-independent de novo sequencing, this review outlines their respective advantages and limitations in terms of sample throughput, sequence coverage, post-translational modification characterization, and data analysis complexity. In addition, this review discusses emerging technological trends, including the integration of ion mobility separation, native mass spectrometry, and artificial intelligence-driven data interpretation, which are expected to enhance the depth and accuracy of antibody characterization. Although current methods continue to face challenges related to sample complexity, dynamic range, and unambiguous sequence variant assignment, we emphasize the importance of integrating BCR-seq and Ab-seq data to construct gene-protein association maps. These maps help validate sequence accuracy and facilitate epitope discovery. This dual-platform strategy helps bridge the gap between genotype and phenotype, thereby enhancing both the resolution and scope of antibody repertoire studies. Such an integrative approach also offers a valuable tool for therapeutic antibody development, structure-function analysis, and precise evaluation of vaccine efficacy.
2.Identification and infection rate of densovirus in Culex pipiens pallens in Beijing in 2023
Xiu-yan XU ; Ting YAN ; Si-jie ZHU ; Jing LI ; Mei-de LIU ; Hong-jiang ZHANG ; Ting LIU ; Qiu-hong LI ; Xiao-jie ZHOU ; Ying TONG ; Yong ZHANG
Acta Parasitologica et Medica Entomologica Sinica 2026;33(1):25-30
Objective This study conducted molecular biological identification of the viruses carried by Culex pipiens pallens specimens collected in Shunyi District, Beijing in 2023, and observed the changes in the infection rate of the viruses carried by Cx. pipiens pallens at different collection times. Methods Cx. pipiens pallens were collected using carbon dioxide mosquito traps. The mosquito samples were ground in batches and analyzed by molecular biology technologies. The virus infection rate at different collection times was analyzed statistically. Results 17 strains of Culex pipiens pallens densovirus(CppDNV)were identified from Cx. pipiens pallens samples collected in Shunyi District, Beijing, in 2023. The nucleotide sequence analysis of the virus genome coding region showed that CppDNV was a single-stranded DNA virus with a total length of 3 335 nt, encoding 2 non-structural proteins(NS1, NS2)and 1 capsid protein(VP). The nucleotide(amino acid)sequence lengths of the three proteins were 2 376 nt(791 aa),1 092 nt(363 aa)and 1 071 nt(356 aa), respectively. Phylogenetic analysis showed that CppDNV was located in genus Brevihamaparvovirus. Statistical analysis showed no significant difference in infection rates across collection times(χ2=4.429, P=0.194). Conclusions CppDNV was identified in Cx. pipiens pallens in Beijing, and it was stably maintained in this natural population.
3.Analysis of VWF Gene c.7332G>A Nonsense Mutation Pedigree and Study of Molecular Pathogenesis
Duan-Yang WANG ; Lei WANG ; Dong-Yan FU ; Xiao-Mei LU ; Li-Dong ZHAO ; Jia-Wei ZHENG ; Ya-Lin YU ; Gang WANG ; Lin-Hua YANG
Journal of Experimental Hematology 2025;33(6):1701-1707
Objective:To analyze the genetic characteristics of the VWF gene c.7332G>A nonsense mutation and explore its molecular pathogenesis.Methods:Phenotypic diagnosis of the proband was performed using VWF:Ag,VWF:RCo,FⅧ:C and multimeric analysis.The probands were genotyped by NGS whole-exome sequencing,and the sequencing results were validated by sanger sequencing.The family members were genotyped by Sanger sequencing.The VWF gene c.7332G>A nonsense mutant plasmid was constructed.After transfection,the function of VWF gene c.7332G>A mutant plasmid was verified at cell level in vitro.The mRNA level was detected by qRT-PCR,and the expression level of protein was detected by Western blot,the function of multimerization was verified by the multimeric analysis.Results:VWF:Ag and VWF:RCo were all less than 3%in the proband,and the multimeric analysis showed multimer deficiency.The proband was diagnosed as type 3 VWD.The homozygous nonsense mutation of VWF gene c.7332G>A was detected by gene sequencing.The VWF mRNA level of the mutant plasmid was decreased,and the VWF protein expression in the cell supernatant was decreased,the mutant protein was truncated and the function of VWF multimerization was impaired.Conclusion:A homozygous mutation in exon 43 of VWF gene,c.7332G>A,was responsible for the probands type 3 VWD in the proband.The mutation caused a decrease in the relative level of VWF mRNA and protein,and impaired the function of VWF multimerization.
4.Gene Mutation Analysis of an Individual with a RHD Variant RHD*DV.5 and RHD Negative Gene Heterozygote
Shi-Shi WU ; Juan PENG ; Li-Bo WU ; Hong-Xiao CHEN ; Dong-Mei ZHAN ; Yue-Mei DONG ; Wan-Qin WANG ; Liang WU
Journal of Experimental Hematology 2025;33(6):1758-1764
Objective:To perform RHD gene detection on a blood sample with serological weak D phenotype.Methods:A specimen received by the People's Hospital of Zhijin County was serologically identified by the microcolumn gel method and saline method.RHD gene detection was conducted by the PCR-SSP method,and the full sequence determination of the 10 exons amplified was performed.The sequencing results were compared with the ISBT database to determine the genotype.Bioinformatics tool was used to predict the functional damage of mutant proteins,and Alphafold-3 was used for tertiary structural modeling of wild-type and mutant RhD proteins,and the structures of the two proteins were compared and analyzed to explore the reasons why mutations lead to weak serological manifestations.Results:The patient's genotype was identified as RHD*DV.5/RHD*01N.01 heterozygote,with the complete deletion of RHD genes on one chromosome,unable to express the D antigen.On the other chromosome,a G>A mutation occurred at the 697th base of the 5th exon,resulting in a partial D phenotype.This mutation causes internal hydrogen bond changes at the 233 position of RhD protein,resulting in a change in the conformation of the protein,affecting binding to the corresponding antibody.Conclusion:The patient is a heterozygous mutant individual with RHD*DV.5/RHD*01N.01,exhibiting a partial D phenotype serologically.This variation is extremely rare and has been scarcely reported globally.
5.Optimization Study of Rat Models for Sequelae of Pelvic Inflammatory Disease
Zhen LIU ; Wei-ling WANG ; Yun-cheng MA ; Yu-xi WANG ; Yuan TIAN ; Qian LI ; Xiao-zhu WANG ; Xiao-yao LIU ; Mei JIANG ; Wen-hui XU ; Jian GAO ; Ting WANG
Progress in Modern Biomedicine 2025;25(12):1921-1930
Objective:To establish a stable rat model of sequelae of pelvic inflammatory disease(SPID)with clinical characteristics,and to provide a reliable experimental model for the study of the pharmcological effect and mechanism of SPID.Methods:Twenty-four 7-week-old SD rats were divided into sham operation group,model-A(108 cfu/mL mixed bacterial solution,0.2 mL),model-B(109 cfu/mL mixed bacterial solution 0.2 mL),and model-C(108 cfu/mL E.coli 0.2 mL).The weight of the rat's uterine was weighed and the uterine index was calculated.The automatic hematology analyzer was used to detect the blood routine;hematoxylin-eosin staining(HE)and masson staining were used to detect uterine pathlogical changes in rats.Enzyme-linked immunosorbent assay(ELISA)was used to detect interleukin-1β(IL-1β),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)in rat uterine tissue homogenates.Western blot was used to detect the expression of proteins related to NF-κB signaling pathway.Results:Compared with the sham operation group,the uterine index of model-A,model-B,and model-C were significantly increased(P<0.05,P<0.01).The levels of WBC and NE in the model-A increased significantly(P<0.01).The level of LY in model-B decreased significantly(P<0.01).The levels of IL-1β,TNF-α in model-A,model-B,and model-C were significantly increased(P<0.01).The levels of IL-6 in model-A and model-B were significantly increased(P<0.05,P<0.01).The collagen volume fraction of model-A and model-B were significantly increased(P<0.01).Mechanism study indicates that the expression levels of p-IKKβ/IKKβ,p-IκBα/IκBα and p-p65/p65 in model-A were significantly increased(P<0.01),and the expression levels of IκBα/β-actin were significantly decreased(P<0.01).The expression level of p-IKKβ/IKKβ in model-B was significantly increased(P<0.01).Conclusions:A stable rat model of SPID that conforms to clinical characteristics can be successfully constructed by combining 0.2 mL of mixed bacterial solution with a concentration of 108 cfu/mL and mechanical injury.This modeling method intervened in the expression of the NF-κB inflammatory signaling pathway.
6.Engineered MSCs-EV for repairing cartilage damage with a focus on delivery of curcumin
Xiao-ming DU ; Yu-lin MA ; Xue-qing DUAN ; Zhao-xi YANG ; Xian-zhe ZHANG ; Jin-ming ZHANG ; Yi-mei HU
Chinese Pharmacological Bulletin 2025;41(7):1222-1226
Mesenchymal stem cells(MSCs)play a crucial role in tissue repair and regeneration,and the extracellular vesicle(EV)released by them holds great promise for applications in clinical biomarkers,vaccines,and drug delivery.However,MSCs-derived EV(MSCs-EV)face challenges such as low pro-duction yield,poor retention,and targeted delivery issues.There-fore,engineering MSCs-EV to enhance their performance and en-able visual research has become a hot topic.Curcumin(CUR),an active component in traditional chinese medicine,exhibits pharmacological effects but has limited bioavailability.Using MSCs-EV as a carrier for CUR delivery can address its solubility and bioavailability challenges.This article reviews the drug loading methods,engineering strategies of MSCs-EV,and their important applications in the delivery and treatment of CUR for cartilage injury diseases.It provides a basis for the clinical ap-plication of engineered MSCs-EV in CUR delivery for cartilage repair,offering potential solutions to the challenges in cartilage tissue repair.
7.Effect of total flavones of Coreopsis tinctoria Nutt on vascular dementia by inhibiting miR-93-mediated TLR4 signaling pathway and its mechanism
Meng-ying HU ; Dong-mei YANG ; Yi-zhong ZHU ; Qin-lan LIANG ; Houwati NUERBAHETI ; Xiao-jun YANG ; Hasimu HAMULATI
Chinese Pharmacological Bulletin 2025;41(7):1237-1244
Aim To investigate the effect of total fla-vones of Coreopsis tinctoria Nutt(CF)on cognitive im-pairment in vascular dementia(VD).Methods The VD rat models were established by modified bilateral common carotid arteries ligation method.SD rats were divided into the sham operation group,model group,positive control group(nicergoline),and low,medium,and high dose CF groups.After eight weeks of admin-istration,the short term memory and spatial learning and memory abilities were evaluated by the platform jumping test,dark avoidance test and Morris water maze test.The pathological changes of the hippocam-pal tissues were inspected by HE and Nissl staining.The contents of TNF-α and IL-1β in the hippocampal were examined by ELISA.The protein expression lev-els of TLR4,MyD88,NF-κB p65,and p-NF-κB p65 in the hippocampal were detected by Western blot.The mRNA expression levels of miR-93,TLR4,MyD88,and NF-κB p65 in the hippocampal were determined by qRT-PCR.Results CF obviously improved the short term memory and spatial learning and memory abilities of VD rats,and alleviated the pathological damage of the hippocampus.CF also obviously decreased the lev-els of TNF-α and IL-1β,declined the protein expres-sion levels of TLR4,MyD88,and p-NF-κB p65,and re-duced the miR-93,TLR4,and MyD88 mRNA expres-sion in the hippocampus.Conclusion CF has a nota-ble protective effect on the neuroinflammation and cog-nitive impairments in VD rats by inhibiting the miR-93-mediated TLR4 signaling pathway.
8.Salidroside alleviates progression of Parkinson's disease by modulating inflammatory responses
Xiao-lin DONG ; Gang WU ; Yan-ping LI ; Li-juan ZHANG ; Fu-rong JIN ; Rui LI ; Hong-mei LI ; Xiao-xiao ZHANG ; Qing-yun LI
Chinese Pharmacological Bulletin 2025;41(7):1340-1345
Aim To explore the neuroprotective effects of salidroside on Parkinson's disease(PD)through modulation of inflammatory responses and the underly-ing mechanisms.Methods Mice were divided into five groups:healthy control group,1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)disease group,low-dose Rhodioloside intervention group,medium-dose salidroside intervention group,and high-dose salidro-side intervention group.MPTP-induced PD mouse model was established,and salidroside intervention was administered.Behavioral changes,inflammatory cyto-kine levels,autophagy-related protein expression,and neurons were observed through histological analysis and immunohistochemical staining.Results After MPTP treatment,mice exhibited significant behavioral chan-ges,increased pro-inflammatory cytokines,decreased anti-inflammatory cytokines,reduced autophagy-related proteins,and evident pyroptosis.Salidroside interven-tion alleviated these changes in a dose-dependent man-ner.Conclusions Salidroside exerts neuroprotective effects on PD by alleviating inflammatory responses and promoting autophagy,thereby protecting neurons.
9.Tumor microenvironment metabolism:an ongoing therapeutic target
Ji-tong ZHAO ; Mei-qi FENG ; Xiao-yan ZHANG
Fudan University Journal of Medical Sciences 2025;52(5):724-732
Tumor microenvironment(TME)is the foundation for tumor survival,which is composed of various types of cells,tumor blood vessels,secretory factors,and extracellular matrix(ECM)within the tumor.The unique regulatory mechanism triggered by the vigorous metabolic demand of tumor plays an important role in its tumorigenesis,metastasis,invasion,and treatment resistance.A deeper understanding of the metabolic transformation and tumor-immune cell interactions in the TME will enable the development of therapeutic technologies that precisely target TME metabolism,facilitate the development of combination treatment strategies,and improve the clinical response rate of existing immunotherapies.This paper reviews the composition,metabolism and regulatory mechanisms of TME,summarizes the research progress of immunotherapy strategies targeting the physiological characteristics of TME,and discusses the prospects for clinical application of precision immunotherapy strategies targeting TME,which are expected to enhance immunotherapy drugs response and infiltration degree.
10.PKCβ inhibitor modulates macrophage phenotype and affects kidney ischemia-reperfusion injury during transplantation
Chunyan LI ; Ting XIAO ; Bangcui WU ; Yong CHEN ; Mei TIAN
The Journal of Practical Medicine 2025;41(1):23-29
Objective To investigate whether PKCβ inhibitor can alleviate RIRI by regulating macrophage phenotype.Methods Rats in the renal ischemia-reperfusion injury(RIRI)model group underwent right nephrec-tomy followed by a 60-minute clamping of the left renal pedicle.In the experimental group(Inhibitor+RIRI),PKCβ inhibitors were administered orally one day prior to surgery.All rats were euthanized 24 hours post-surgery for the collection of blood and left kidney samples.Renal function,tissue morphology,and the expression levels of renal tubular injury marker KIM-1,renal papilla injury marker RPA-1,macrophage subtype markers,and inflammatory factors were evaluated.Results PKCβ inhibitors alleviated renal ischemia-reperfusion injury in rats.PAS staining revealed marked tubular damage in kidney sections from the RIRI group,whereas kidney inflammatory cell infiltra-tion and renal tubular injury scores were significantly reduced in the Inhibitor+RIRI group following PKCβ inhibitor treatment(all P<0.05).The expression levels of Cr,BUN,KIM-1,and RPA-1 were markedly elevated in the RIRI group compared to the Sham and Inhibitor+RIRI groups(all P<0.05).After PKCβ inhibitor intervention,the expression levels of Cr,BUN,KIM-1,and RPA-1 were significantly decreased in the Inhibitor+RIRI group relative to the RIRI group(all P<0.05).Protein expression levels of iNOS,IL-2,and CD197 in the kidney tissue of the RIRI group were significantly higher than those in the Sham and Inhibitor+RIRI groups(all P<0.05).Compared with the RIRI group,the protein expression levels of iNOS,IL-12,and CD197 were significantly reduced in the Inhibitor+RIRI group following PKC β inhibitor intervention(all P<0.05).Additionally,the protein expression levels of Dectin-1,ARG-1,and CD163 were significantly higher in the Inhibitor+RIRI group than in the RIRI and Sham groups after PKCβ inhibitor intervention(all P<0.05).Conclusions PKCβ inhibitors can mitigate renal dysfunction,renal tubular injury,and the expression of injury markers in the renal tubules and renal papilla follow-ing ischemia-reperfusion.Additionally,PKCβ inhibitors play a role in modulating macrophage subtypes by reducing M1 macrophages and promoting polarization to M2,which leads to a decrease in pro-inflammatory factors and an increase in anti-inflammatory factors,ultimately facilitating kidney repair.


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