Patients with metastatic castration-resistant prostate cancer (mCRPC) face poor prognoses due to tumor heterogeneity and drug resistance. Antibody-drug conjugates (ADCs) have been under development for over two decades for mCRPC treatment. Several clinical trials have demonstrated promising antitumor activity and acceptable safety profiles for ADCs in this setting. Among prostate-specific membrane antigen (PSMA)-targeted ADCs, ARX517 demonstrates superior safety and more significant prostate-specific antigen (PSA) reductions compared to earlier agents such as MLN2704, PSMA-ADC, and MEDI3726. ADCs targeting B7-H3, such as MGC018 and DB-1311, have also shown antitumor activity. ADCs targeting other antigens, including six-transmembrane epithelial antigen of the prostate (STEAP)1 (DSTP3086S), trophoblast cell surface antigen (TROP)2 (sacituzumab govitecan), and solute carrier (SLC) 44A4 (ASG-5ME), have shown preliminary antitumor activity in early trials but face challenges with insufficient efficacy or toxicity. Tisotumab vedotin (targeting tissue factor) has shown no significant therapeutic response in mCRPC. Meanwhile, disitamab vedotin (HER2-targeted), ABBV-969 and DXC008 (both dual PSMA/STEAP1-targeted) are currently under evaluation. Notably, an international multicenter phase Ⅲ clinical trial (NCT06925737) for mCRPC has been initiated in May 2025 for evaluating B7-H3-targeted ADC ifinatamab deruxtecan. This review summarizes recent advances in ADCs targeting key antigens in mCRPC (including PSMA, B7-H3, STEAP1, TROP2, SLC44A4, and others) and explores combination strategies, offering insights to inform the clinical management of mCRPC.
Humans ; Prostatic Neoplasms, Castration-Resistant/pathology* ; Male ; Immunoconjugates/therapeutic use* ; Glutamate Carboxypeptidase II/immunology* ; Antibodies, Monoclonal, Humanized/therapeutic use* ; B7 Antigens/immunology* ; Neoplasm Metastasis ; Prostate-Specific Antigen ; Antigens, Neoplasm/immunology* ; Antigens, Surface ; Camptothecin/analogs & derivatives* ; Oxidoreductases

OBJECTIVE: To investigate the serological prevalence of high-titer IgG antibodies against 2019-nCoV among voluntary blood donors in Zunyi. METHODS: The blood plasma specimens were diluted at 1∶160 or 1∶320, then tested for the presence of 2019-nCoV IgG antibodies by using an indirect enzyme-linked immunosorbent assay(ELISA). The differences of antibody reactive rate among different genders, ages, and blood types were analyzed. RESULTS: 1 523 reactive specimens were identified in 5 378 specimens which were diluted at a ratio of 1∶160. Similarly, 329 reactive specimens were identified in 2 988 diluted at 1∶320. The overall reactive rate for antibodies was 22.1%. It was observed that females, individuals over the age of 40, and those with blood type AB exhibited higher high-titer antibody reactive rate. CONCLUSION After entering a new stage of 2019-nCoV infection prevention and control, there is a relatively high detection rate of high-titer 2019-nCoV IgG antibodies among voluntary blood donors in Zunyi. The reactive rate of antibodies varies among different genders, ages, and blood types.
Humans ; Blood Donors ; Immunoglobulin G/blood* ; Antibodies, Viral/blood* ; SARS-CoV-2/immunology* ; COVID-19 ; Female ; Enzyme-Linked Immunosorbent Assay ; Adult ; China ; Male ; Middle Aged

OBJECTIVE: To investigate the pattern of hepatitis B virus (HBV) infection and the prevalence of hepatitis D virus (HDV) infection among voluntary blood donors who tested reactive for HBV in Wuhan, and to provide data support for the prevention and treatment of HBV and HDV infections. METHODS: Electrochemiluminescence (ECL) method was used to detect hepatitis B serological markers in the samples with HBsAg and/or HBV DNA reactivity, and the HBV infection in different groups was statistically analyzed. The HDV IgM and IgG antibodies were screened by ELISA, and the prevalence of HDV infection in the retained samples was analyzed. RESULTS: In 351 ELISA and/or nucleic acid test (NAT) reactive samples, the serological tests for hepatitis B revealed that 4 cases (1.1%) were positive for HBsAg, HBeAg, and anti-HBc, 182 cases (51.9%) were positive for HBsAg, anti-HBe, and anti-HBc, and 55 cases (15.7%) were negative for HBsAg but positive for anti-HBc. Among them, the HBsAg ELISA dual reagent reactive group (HBsAg R&R group) and the HBsAg ELISA single reagent reactive/HBV DNA reactive group (HBsAg R&NR/HBV DNA R group) had the highest rates of HBsAg(+), anti-HBe(+), and anti-HBc(+), accounting for more than 90% and 65%, respectively, followed by low activity of HBV acute infection or chronic carriers, accounting for about 5% and 20%, respectively. In the HBsAg R&NR/HBV DNA NR group, the combined proportion of individuals with anti-HBs single positive and all hepatitis B serological markers negative accounted for 78%, and those who were HBsAg negative but anti-HBc positive accounted for approximately 20%. In the HBsAg NR&NR/HBV DNA R group, there was nearly 9% of HBsAg(+), anti-HBe(+), and anti-HBc(+), the remaining were all HBsAg negative but anti-HBc positive, with a 100% anti-HBc positivity rate in this group. No HDV IgM or IgG antibodies were detected in the retained samples. CONCLUSION Blood donors with HBV-reactive results in blood screening exhibit multiple patterns of infection indicators. The prevalence rate of HDV infection among blood donors in Wuhan is extremely low. However, the risk of asymptomatic occult hepatitis B infection (OBI) blood donors being co-infected with HDV should not be overlooked in areas with high prevalence of HBV.
Humans ; Blood Donors ; Hepatitis B/blood* ; China/epidemiology* ; Adult ; Male ; Female ; Hepatitis D/epidemiology* ; Middle Aged ; Hepatitis B virus/immunology* ; Hepatitis B Antibodies/blood* ; Young Adult ; DNA, Viral/blood* ; Hepatitis B Surface Antigens/blood* ; Prevalence ; Adolescent

Programmed cell death 1 (PD-1) inhibitor therapy for lung adenocarcinoma may induce rare but severe hematologic adverse events, including severe anemia. Although glucocorticoids are recommended for managing immune-related adverse events, therapeutic experience with PD-1 inhibitor-induced severe anemia remains limited, and its efficacy and safety have not been fully validated. This article reports a case of advanced lung adenocarcinoma in which severe anemia developed following combination therapy with chemotherapy and PD-1 inhibitor. After comprehensive evaluation, the patient was diagnosed with anemia of inflammation (AI) and achieved significant hemoglobin recovery following high-dose glucocorticoid treatment. These findings may provide new insights into the recognition and management of this rare hematologic toxicity in clinical practice.
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Humans ; Adenocarcinoma of Lung/drug therapy* ; Programmed Cell Death 1 Receptor/antagonists & inhibitors* ; Anemia/etiology* ; Immunotherapy/adverse effects* ; Lung Neoplasms/immunology* ; Male ; Antibodies, Monoclonal/therapeutic use* ; Middle Aged

BACKGROUND: Epstein-Barr (EB) virus infection stimulates the production of vascular endothelial growth factor (VEGF), which contributes to the progression of angiogenesis. Angiogenesis plays an important role in the development of atherosclerosis. Since serum anti-early antigen EB virus IgG (EBV EA-IgG) titer is a sign of active EB virus infection, EBV EA-IgG titer could be associated with atherosclerosis. The number of minor (T) alleles in VEGF polymorphism rs3025039 has been reported to be inversely associated with serum VEGF concentration, suggesting that rs3025039 might have a strong influence on the association between EBV EA-IgG titer and atherosclerosis. By focusing on the role of VEGF in the development of atherosclerosis, this study aimed to investigate the association between active EB virus infection and atherosclerosis. METHODS: A cross-sectional study of 2,661 older Japanese individuals aged 60-89 years who participated in annual health check-ups during 2017-2019 was conducted. Logistic regression was used to evaluate the association between EBV EA-IgG titer and atherosclerosis in relation to rs3025039 genotype. The influence of rs3025039 (T) allele carrier status on the association between EBV EA-IgG titer and atherosclerosis was also evaluated by using logistic regression. RESULTS: Among rs3025039 CC-homozygotes, with the lowest EBV EA-IgG titer tertile as the reference, the multivariable odds ratio (95% confidence interval) was 1.11 (0.82, 1.50) for the medium tertile and 1.07 (0.78, 1.47) for the high tertile. Among rs3025039 (T) allele carriers, the corresponding values were 1.44 (0.88, 2.36) and 1.88 (1.15, 3.05), respectively. There was a significant interaction between rs3025039 (T) allele carrier status and the association between EBV EA-IgG titer and atherosclerosis (adjusted p = 0.0497). CONCLUSION EBV EA-IgG titer was significantly positively associated with atherosclerosis only among participants who are genetically less likely to have progressive angiogenesis. An angiogenesis-related genetic factor was revealed as a determinant of the association between EBV EA-IgG titer and atherosclerosis. These findings introduce a novel concept that could explain the association between viral infection and atherosclerosis.
Humans ; Aged ; Male ; Middle Aged ; Female ; Japan/epidemiology* ; Atherosclerosis/virology* ; Aged, 80 and over ; Vascular Endothelial Growth Factor A/genetics* ; Epstein-Barr Virus Infections/virology* ; Polymorphism, Single Nucleotide ; Cross-Sectional Studies ; Herpesvirus 4, Human ; Antigens, Viral/immunology* ; Antibodies, Viral/blood* ; Immunoglobulin G/blood* ; Genotype ; East Asian People

INTRODUCTION: Rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody (ACPA) are used in the diagnosis and prognostication of rheumatoid arthritis (RA). We wanted to determine the specific contributions of RF and ACPA to the biological nature of RA and whether they act synergistically. METHODS: We identified 731 patients from our prospective multi-ethnic RA cohort and categorised them into four groups: ACPA-positive, RF-positive, doubly positive and doubly negative. We compared the demographics, Disease Activity Score-28, Health Assessment Questionnaire score, quality of life using Short Form 36 and the use of prednisolone and disease-modifying antirheumatic drugs (DMARDs) of these patient groups. RESULTS: Four hundred and ninety-one patients (67.2%) were ACPA+RF+, 54 (7.4%) were ACPA+RF-, 82 (11.2%) were ACPA-RF+ and 104 (14.2%) were ACPA-RF-. Mean disease duration before the study entry was not different in the four groups. Patients with older age of onset were less likely to be positive for RF and ACPA. Fewer ACPA+RF+ patients were in remission compared to those in the other groups ( P < 0.05). Erythrocyte sedimentation rate (ESR) was higher at study entry in the ACPA+RF+ group (40.4 mm/h vs. 30.6-30.9 mm/h, P < 0.05). Prednisolone and number of DMARDs used were higher in the ACPA+RF+ group compared to the doubly negative group. There were no differences in the functional status and quality of life. CONCLUSIONS RA patients who were positive for both ACPA and RF had lower remission rate, higher baseline ESR and required more corticosteroid and DMARD treatment compared to those who were singly positive or doubly negative. Being doubly positive confers a worse outcome to RA patients.
Humans ; Arthritis, Rheumatoid/diagnosis* ; Male ; Female ; Middle Aged ; Rheumatoid Factor/blood* ; Anti-Citrullinated Protein Antibodies/blood* ; Adult ; Quality of Life ; Prospective Studies ; Antirheumatic Agents/therapeutic use* ; Aged ; Peptides, Cyclic/immunology* ; Prednisolone/therapeutic use* ; Surveys and Questionnaires ; Severity of Illness Index ; Prognosis

To prepare antibodies that specifically recognize the conserved domain in the large extracellular loop of the CD63 protein, we expressed anti-CD63 single-chain variable fragment (scFv) antibody in Pichia pastoris in a secreted form. The purified expression product was found to bind specifically with CD63 protein and recognize CD63 on the surface of SK-MEL-28 cells. The variable region of the anti-CD63 monoclonal antibody in an anti-CD63-positive cell line was sequenced. The anti-CD63 scFv consisted of a variable heavy chain and a variable light chain linked by a flexible peptide was then designed. After codon optimization, the gene was synthesized and cloned into the expression plasmid pPICZα-A. The SacI-linearized plasmid was electroporated into P. pastoris X33, and 1% methanol were used to induce the expression of scFv. The fermentation supernatant was purified by Ni column. Anti-CD63 scFv was identified by SDS-PAGE and Western blotting, and its biological activities were analyzed by immunoblotting, immunofluorescence, cell-based ELISA, and flow cytometry. A P. pastoris strain capable of expressing and secreting anti-CD63 scFv was successfully obtained. The antibody had a molecular weight of approximately 30 kDa and specifically recognized CD63 protein. The expression of anti-CD63 scFv in P. pastoris paves the way for the production of anti-CD63 antibodies on a large-scale, which is undoubtedly an economical and effective way of antibody acquisition.
Single-Chain Antibodies/immunology* ; Humans ; Tetraspanin 30/immunology* ; Recombinant Proteins/immunology* ; Pichia/genetics* ; Saccharomycetales/metabolism*

This study is designed to address the development, synthesis, and screening of non-animal-derived nanoantibody libraries. Furthermore, it seeks to elucidate the impact of framework region selection and complementarity-determining region (CDR) design on the characteristics of synthesized nanoantibody libraries. These investigations aim to establish a robust theoretical and technical foundation for enhancing the efficacy, diversity, and practical applicability of synthetic nanoantibody libraries. In this study, a new framework (IGHV3S65*01-IGHJ4*01) was identified based on the high-throughput sequencing results of natural nanobodies, and degenerate primers were designed based on the frequency of amino acids at each position in the complementarity-determining region (CDR) region to synthesize the coding fragments of nanobodies by overlap PCR. After 40 times of electro-transformation, a single-frame synthesized nanobody library (SS-Library) containing 6×10⁹ clones was obtained, and the titer of the library was demonstrated to be 10¹³ PFU/mL after rescue by the helper phage M13K07. Random 48 single colonies were picked for PCR, which revealed an insertion rate of 95.8%. Sanger sequencing results showed that 38 clones had complete sequences, none of which showed cysteines or stop codons, and no identical sequences appeared, suggesting that the library had higher diversity. The library was screened and validated with three antigens, including bovine serum albumin (BSA), acetylcholinesterase (AchE), and immunoglobulin G (IgG). Finally, 2 nanobodies against BSA, 10 against AchE, and 15 against IgG were obtained. One positive clone of each antigen was singled out for recombinant expression, and the results showed that all the three nanobodies were expressed in a soluble form. The binding activity of recombinantly expressed nanobodies was evaluated using indirect enzyme-linked immunosorbent assay (ELISA) and bio-layer interferometry (BLI). The results demonstrated that the anti-AChE and anti-IgG nanobodies exhibited specific binding to their respective antigens, with affinity constants (KD) of 294 nmol/L and 250 nmol/L, respectively. The nanobody synthetic library preparation method proposed in this study is simple and easy to use with low preference, and it is expected to be a universal nanobody discovery platform for the preparation and development of lead specific nanobodies.
Single-Domain Antibodies/biosynthesis* ; Peptide Library ; Complementarity Determining Regions/immunology* ; Animals

Hemoglobin, the principal protein in red blood cells, is crucial for oxygen transport in the bloodstream. The quantification of hemoglobin concentration is indispensable in medical diagnostics and health management, which encompass the diagnosis of anemia and the screening of various blood disorders. Immunological methods, based on antigen-antibody interactions, are distinguished by their high sensitivity and accuracy. Consequently, it is necessary to develop hemoglobin-specific antibodies characterized by high specificity and affinity to enhance detection accuracy. In this study, we immunized a Bactrian camel (Camelus bactrianus) with human hemoglobin and subsequently constructed a nanobody library. Utilizing a solid-phase screening method, we selected nanobodies and evaluated the binding activity of the screened nanobodies to hemoglobin. Initially, human hemoglobin was used to immunize a Bactrian camel. Following four immunization sessions, blood was withdrawn from the jugular vein, and a nanobody library with a capacity of 2.85×10⁸ colony forming units (CFU) was generated. Subsequently, ten hemoglobin-specific nanobody sequences were identified through three rounds of adsorption-elution-enrichment assays, and these nanobodies were subjected to eukaryotic expression. Finally, enzyme-linked immunosorbent assay and biolayer interferometry were employed to evaluate the stability, binding activity, and specificity of these nanobodies. The results demonstrated that the nanobodies maintained robust binding activity within the temperature range of 20-40 ℃ and exhibited the highest binding activity at pH 7.0. Furthermore, the nanobodies were capable of tolerating a 10% methanol solution. Notably, among the nanobodies tested, VHH-12 displayed the highest binding activity to hemoglobin, with a half maximal effective concentration (EC₅₀) of 10.63 nmol/L and a equilibrium dissociation constant (K_D) of 2.94×10^-7 mol/L. VHH-12 exhibited no cross-reactivity with a panel of eight proteins, such as ovalbumin and bovine serum albumin, while demonstrating partial cross-reactivity with hemoglobin derived from porcine, goat, rabbit, and bovine sources. In this study, a hemoglobin-specific high-affinity nanobody was successfully isolated, demonstrating potential applications in disease diagnosis and health monitoring.
Animals ; Camelus/immunology* ; Single-Domain Antibodies/immunology* ; Hemoglobins/immunology* ; Humans ; Peptide Library

Bio-mineralization has emerged as a promising strategy to enhance vaccine immunogenicity. This study optimized the calcium phosphate (CaP) mineralization process of foot-and-mouth disease virus-like particles (FMD VLPs) to achieve high mineralization efficiency and scalability. Key parameters, including concentrations of Ca²⁺, HPO₄^2-, NaCl, and VLPs, as well as stirring speed, were systematically optimized. Stability of the scaled-up reaction system and immunogenicity of the mineralized vaccine were evaluated. Optimal conditions [25.50 mmol/L Ca(NO₃)₂, 15 mmol/L Na₂HPO₄, 300 mmol/L NaCl, 0.75 mg/mL VLPs, and 1 500 r/min] yielded CaP-mineralized VLPs (VLPs-CaP) with high mineralization efficiency, uniform morphology, and a favorable particle size. Scaling up the reaction by 25 folds maintained consistent mineralization efficiency and particle characteristics. Immunization in mice demonstrated that VLPs-CaP induced higher titers of specific antibodies and neutralizing antibodies than unmineralized VLPs (P < 0.05). Higher IgG2a/IgG1 ratio and enhanced IFN-γ secretion (P < 0.05) further indicated robust cellular immune responses. We establish a stable and scalable protocol for VLPs-CaP, providing a theoretical and technical foundation for developing high-efficacy VLPs-CaP vaccines.
Vaccines, Virus-Like Particle/immunology* ; Immunogenicity, Vaccine ; Calcium Phosphates/chemistry* ; Foot-and-Mouth Disease Virus ; Biomineralization ; Particle Size ; Animals ; Mice ; Antibodies, Neutralizing/blood* ; Antibodies, Viral/blood* ; Immunity, Cellular