Search Results (853)

Human metapneumovirus (HPMV) is a significant pathogen that causes lower respiratory tract infections. Given the weak immunogenicity thereof, and the few relevant studies, the utility of the viral membrane protein G as a vaccine remains controversial. In this study, the G extracellular domain (RMG) of HMPV was expressed either alone or fused with the cholera toxin B subunit (CTB) and “cross-reacting material 197” (CRM197) carrier proteins (giving G-CTB/G and CRM197), to enhance immunogenicity. The non-glycosylated G protein (REG) expressed in Escherichia coli served as a control. SDS-PAGE and anti-His tag Western blotting verified that each protein was successfully expressed and correctly identified. BALB/c mice were immunized with each protein and subjected to challenge with HMPV. The results showed that, although immunization with RMG alone failed to induce potent neutralizing antibodies, it modestly reduced viral loads in the lungs of mice. However, the pathological damage caused by lung inflammation was more aggravated than that of the control challenge group. The level of specific IgG antibody induced by the recombinant G-CTB was significantly higher than that elicited by RMG. Compared to the RMG group, the viral load in the lungs of the G-CTB group tended to be reduced. Also, the damage caused by lung inflammation was significantly alleviated. Our study proves that HMPV G may be a valuable antigen in terms of HMPV vaccine development and offers a promising strategy for modulating the immunogenicity and safety thereof. Full article

Prostate cancer (PCa) progression and treatment resistance are driven by tumor-intrinsic mechanisms and adaptive remodeling of the tumor microenvironment, in which cancer-associated fibroblasts (CAFs) play a crucial role. Although CAF biology is increasingly recognized, a major translational gap remains: CAFs are highly heterogeneous, and comprise distinct functional states with divergent effects on disease progression, immune regulation, and therapeutic resistance. To bridge this gap, we synthesize evidence from single-cell and spatial transcriptomic studies, tissue-based pathology, liquid biopsy assays, and molecular imaging to construct an evidence-tiered, decision-oriented translational framework that connects stromal mechanisms, translational measurement strategies, and therapeutic interventions in PCa. Single-cell and spatial transcriptomic analyses have consistently identified multiple CAF programs, including matrix-remodeling, inflammatory, immunoregulatory, antigen-presenting, and therapy-imprinted states, each with distinct functional outputs and clinical correlates. Tissue-based readouts, including reactive stromal grade (RSG) and fibroblast activation protein (FAP) immunohistochemistry, provide practical proxies for stromal activation and correlate with disease-specific mortality and imaging phenotypes. Circulating CAFs (cCAFs) represent an emerging liquid biopsy modality for longitudinal stromal monitoring, although technical standardization is required before clinical implementation. FAP-targeted PET imaging and emerging dual prostate-specific membrane antigen (PSMA)/FAP-targeted theranostic strategies provide noninvasive tools for patient selection and response assessment, particularly in PSMA-discordant or tracer-heterogeneous disease. Androgen receptor (AR)-targeted therapy can reprogram stromal states toward resistance-promoting circuits, highlighting the dynamic and plastic nature of the CAF compartment. A state-based CAF framework organizes stromal biology into testable translational hypotheses rather than immediate clinical standards. RSG and FAP-based tissue or imaging readouts are practical markers of stromal activation, whereas spatial CAF-immune signatures and cCAF assays remain investigational and require assay harmonization and prospective validation. Future trials should pre-specify stromal biomarkers as enrichment or pharmacodynamic variables when matched to the intervention and should avoid treating CAFs as a uniform therapeutic target. Full article

Background/Objectives: The envelope (E) protein of orthoflaviviruses contains antigenic sites that are composed of one or more epitopes, which can vary in antigenic specificity, including between viral species, strains, and even substrains. Monoclonal antibodies (mAbs) that bind these epitopes vary in functionality based on their specificity. This makes mAbs useful to study the differences in phenotypes between strains of viruses, such as the wild type (WT) and live attenuated vaccine strains of yellow fever virus (YFV). mAb 2D12 was raised against the 17D-204 YFV vaccine substrain virus (YF VAX^®) by Schlesinger et al. in 1983. However, it only neutralizes Asibi WT virus, not the 17D-204 vaccine substrain virus. Results: We confirmed these results and demonstrated that mAb 2D12 fails to neutralize all 17D vaccine substrains (17D-204, 17DD, and 17D-213), indicating that the minor differences between these virus substrains do not affect the epitope or functionality of mAb 2D12. In addition, mAb 2D12 was found to neutralize WT strain of French viscerotropic virus (FVV), with statistically indistinguishable neutralization from the WT strain Asibi. All but one of the live attenuated French neurotropic vaccine (FNV) derivative viruses had significantly lower neutralization than WT strains Asibi and FVV. FVV, Asibi, 17D, and FNV have many amino acid differences in the membrane (M) and E proteins. It is unclear which of them contributes to this differential neutralization. However, FNV and 17D have common amino acid substitutions from WT FVV and Asibi at positions M-36 and E-331, suggesting that one or both of these residues may contribute to the 2D12 epitope. Conclusions: Overall, mAb 2D12 is a valuable tool to distinguish WT virulent strains of YFV from live attenuated vaccine strains. Full article

Background/Objectives: Cadherin-13 (CDH13), part of the cadherin family, is attached to the plasma membrane through glycosylphosphatidylinositol. CDH13 plays essential roles in the development of the neurological and vascular systems and is a risk factor for neural and cardiovascular diseases. CDH13 is expressed on the plasma membrane in both mature and uncleaved precursor forms with the prodomain. Although several anti-CDH13 monoclonal antibodies (mAbs) are available for basic research, there have been no reports of anti-CDH13 mAbs that can detect both the mature form and the uncleaved precursor in flow cytometry. Methods: We developed novel anti-human CDH13 mAbs (named Ca₁₃Mabs) using the mature form of CDH13-expressed cells as an antigen. Results: Among Ca₁₃Mabs, a clone, Ca₁₃Mab-17 (IgG_2b, κ) specifically recognized the mature and uncleaved precursor CDH13-overexpressed Chinese hamster ovary-K1 (CHO/CDH13) cells with no detectable cross-reactivity toward 21 other cadherins by flow cytometry. Ca₁₃Mab-17 also detected endogenous CDH13 in human glioblastoma (LN229 and U87MG) and lung mesothelioma (NCI-H2052) cell lines. The dissociation constant (K_D) value of Ca₁₃Mab-17 for LN229 was estimated at 4.1 × 10⁻⁸ M. Furthermore, Ca₁₃Mab-17 detected both the mature and uncleaved precursor CDH13 in Western blotting. It also identified new blood vessels and glioblastoma cells by immunohistochemistry. Conclusions: Ca₁₃Mab-17 is a versatile tool for detecting both mature and uncleaved precursor forms of CDH13 and has potential for tumor diagnosis and therapy. Full article

Background/Objectives: Malaria affects almost half of the world’s population and causes more than 600,000 deaths annually. Young children in malaria-endemic areas have the highest mortality rate because of their immature immune systems. Global efforts to control the disease have had limited success, with two WHO-recommended pre-erythrocytic malaria vaccines showing suboptimal efficacy; no vaccine has yet been approved against the blood stages of the parasite that causes the clinical symptoms of malaria. Therefore, there is an urgent need to identify new vaccine candidates against the parasite’s blood stages to achieve protection against the disease. Methods: Previous studies in our lab identified a few potential vaccine candidates expressed on the surface of malaria-parasite-infected RBCs using sera from disease-resistant children from malaria-endemic regions and a phage-displayed cDNA library generated from P. falciparum. In an innovative approach, we successfully immunized mice using live Plasmodium falciparum-infected red blood cells {Pf-iRBCs (L)}, the membrane fraction of P. falciparum-infected RBCs {Pf-iRBCs (M)}, and live uninfected human red blood cells (hRBCs) in suitable adjuvants. The polyclonal sera produced against Pf-iRBC immunizations were evaluated for specificity and parasite inhibition in vitro and used in a phage display biopanning assay to identify novel antigens on the surface of Pf-iRBCs. Results: Our data indicate that the polyclonal serum produced in BALB/cJ mice, against live Pf-iRBC (L) and their membrane fraction, specifically interacts with surface antigens of parasitic origin on Pf-iRBCs. Additionally, the anti-Pf-iRBC polyclonal serum exhibits significant parasite-killing activity in the in vitro growth inhibition assay (GIA). We have identified both known and novel antigens associated with the Pf-iRBC membrane using phage display cDNA library screening assays. Conclusions: As a proof of concept, our phage display screening identified antigens known to be associated with the Pf-iRBC membrane. Additionally, we identified several unknown Pf-iRBC antigens predicted to be associated with Pf-iRBC membrane (PlasmoDB), suggesting that our approach has the potential to identify novel antigens yet to be evaluated as vaccine candidates against falciparum malaria. In our follow-on studies, we will evaluate the newly identified antigen using an integrated in vitro and in vivo challenge experiment. These studies form the core supporting data for further evaluation of the vaccine potential of novel Pf-iRBC antigens and for follow-on vaccine trials in non-human primates, with an ultimate goal of a malaria vaccine for humans. Full article

Natural killer (NK) cells are promising effectors for cancer immunotherapy, as they can recognize and eliminate tumor cells without prior antigen sensitization. However, insufficient tumor recognition remains a critical limitation that reduces the anticancer efficacy of NK cells against solid tumors. To address this limitation, we developed a lipid-mediated cell membrane engineering strategy to enhance the targeting and cytotoxic efficacy of NK cells toward solid tumors, particularly ovarian cancer cells. In this strategy, poly-L-glutamic acid (PLE) was employed as an ovarian cancer-targeting module due to the specific affinity of PLE for cholesterol-rich membrane domains. To display PLE on NK cells, a lipid moiety is incorporated to anchor PLE onto the NK cell membrane via hydrophobic insertion, enabling rapid and non-genetic surface modification. As a result, the surface-engineered NK cells with PLE-Lipid (i.e., PLE-NK) displayed PLE on the NK cell surface, allowing direct recognition of ovarian cancer cells without compromising the intrinsic properties of NK cells. This enhanced recognition subsequently increased NK–cancer cluster formation by promoting interactions between membrane-presented PLE on NK cells and cholesterol on ovarian cancer cells. Consequently, PLE-NK cells exhibited enhanced cytotoxicity against ovarian cancer cells (i.e., OVCAR-3 cells) and effectively disrupted 3D tumoroids, while PLE-NK cells showed no off-target effects on normal fibroblasts. Collectively, these findings demonstrate that PLE-Lipid-mediated NK surface engineering provides a simple and effective strategy to improve the tumor targeting ability of NK cells and offers a promising platform for NK cell-based immunotherapy against ovarian cancer. Full article

Accurate measurement of antigen-specific antibody responses is essential for evaluating antibody avidity and quantification. Traditional. Enzyme-Linked Immunosorbent Assay (ELISA), while widely used, is limited by lengthy procedures, dependence on secondary antibodies, and inconsistent reproducibility. In this study, biolayer interferometry (BLI) was established and validated for simultaneous quantification and avidity assessment of specific IgM in serum of Larimichthys crocea (Large yellow croaker) using Pseudomonas plecoglossicida outer membrane protein Omp-H as antigen. Sera from immunized and control fish were analyzed by both BLI and ELISA, with systematic comparison between platforms. Optimal serum dilutions were 1:128 for BLI and 1:1024 for ELISA. Validation with another outer membrane protein, Omp-W, confirmed the method’s broad applicability. BLI association signals and avidity indices correlated strongly with ELISA values, yielding consistent results for both antigens. BLI successfully captured specific antibody responses in infected sera and demonstrated superior inter-plate reproducibility compared to ELISA, which exhibited significant inter-plate variation. However, BLI required lower serum dilutions (hence larger volumes) to achieve comparable sensitivity. These findings establish BLI as a rapid, single-step method providing reliable quantitative and avidity data for teleost IgM, offering a reproducible alternative to ELISA with potential applications in vaccine evaluation and aquaculture infection detection. Full article

Background: Porcine epidemic diarrhea virus (PEDV) remains a major threat to the global swine industry, highlighting the urgent need for safe and effective next-generation vaccines. mRNA vaccines have emerged as a promising platform due to their rapid development and favorable safety profile. Objectives: This study aimed to design and perform the preliminary evaluation of a PEDV multi-epitope mRNA vaccine using an immunoinformatics-guided strategy combined with experimental validation. Methods: Immunoinformatics tools were used to identify B-cell and cytotoxic T lymphocyte (CTL) epitopes from the PEDV spike (S), membrane (M), and nucleocapsid (N) proteins. Selected epitopes were assembled into a multi-epitope antigen (E). mRNA constructs encoding S1, S2, and antigen E were synthesized via in vitro transcription and encapsulated into lipid nanoparticles (LNPs). Expression was evaluated in HEK293T cells, and immunogenicity was assessed in mice measuring antigen-specific antibody responses and cytokine levels following immunization. Results: The mRNA constructs exhibited high structural integrity and efficient intracellular translation. The LNP formulations showed good physicochemical stability and delivery efficiency. Immunization with the antigen E mRNA-LNP formulation induced significantly higher PEDV-specific IgG levels compared with control groups. Elevated cytokine levels further indicated activation of both humoral and cellular immune responses. Conclusions: This study presents a feasible workflow for the development of a PEDV multi-epitope mRNA vaccine. The antigen E construct demonstrated favorable immunogenicity in a mouse model, supporting its potential as a promising construct for further investigation and optimization. Although further studies are required to validate antigen expression at the protein level and to further characterize immune mechanisms, these findings provide preliminary evidence supporting the feasibility of multi-epitope mRNA vaccines for PEDV prevention. Full article

Pasteurella multocida (P. multocida) is a significant pathogenic bacterium that causes serious disease and death in the yaks of the Tibetan Plateau, and the existing inactivated vaccines are limited by low protection and reactogenicity. Outer membrane vesicles (OMVs) derived from a yak-origin serogroup B P. multocida isolate were evaluated as a potential vaccine candidate in the present study. The purified OMVs were characterized by transmission electron microscopy and nanoparticle tracking analysis, which demonstrated the presence of typical bilayer vesicles ranging from 20 to 300 nm in diameter. Proteomic profiling revealed 1213 proteins, with many of them being immunologically relevant outer membrane-associated proteins like OmpA, OmpH, Omp16, OmpW, TbpA and PlpP. The functional enrichment analysis showed that these proteins were linked to translation, membrane structure, transport, metabolism, and pathways of adaptation of bacteria. In vitro OMVs were effectively taken up by RAW264.7 macrophages and stimulated robust expression of inflammatory mediators, such as TNF-α, IL-1β, IL-6, iNOS and IL-10, which is indicative of strong innate immunostimulatory capacity. OMV immunization induced significant antigen specific humoral responses in mice and yaks in vivo. In mice, intramuscular immunization was effective in giving full protection against P. multocida challenge but not intranasal immunization. Histopathology also indicated less tissue damage in vaccinated animals, especially in the lung and liver. These findings, taken together, prove that yak-derived P. multocida OMVs have high immunogenicity and protection capabilities, which show their potential as a next-generation vaccine platform to tackle P. multocida infection. Full article

Background: Non-typeable Haemophilus influenzae (NTHi) is a major cause of acute respiratory tract infections and chronic airway disease, despite its clinical importance, no licensed vaccine is available, largely due to the extensive genetic and antigenic diversity among circulating isolates. We previously identified conserved outer membrane proteins capable of inducing systemic protection against NTHi. Methods: In this study, we evaluated whether a multi-antigen protein vaccine composed of conserved NTHi antigens (P5 and P26) could protect against pulmonary infection. Transgenic mice expressing human transferrin and factor H were immunized via the intraperitoneal or intranasal route and challenged intranasally with a clinical NTHi isolate. Bacterial clearance, antigen-specific mucosal and systemic antibody responses, and recruitment of innate immune cells to the airways were assessed. Results: Both immunization routes significantly reduced bacterial loads compared with controls. Vaccination induced robust mucosal and systemic IgG and IgA responses and enhanced early recruitment of macrophages, monocytes, dendritic cells, and neutrophils to the airways. Intranasal immunization elicited strong mucosal antibody responses and was associated with improved local bacterial clearance. Conclusions: These findings demonstrate that multi-antigen vaccines targeting conserved NTHi proteins can elicit effective mucosal and systemic immunity and represent promising candidates for the prevention against NTHi respiratory infections. Full article

Liver diseases, ranging from chronic hepatitis and metabolic dysfunction to cirrhosis and hepatocellular carcinoma, represent a major global public health burden. As an immune-privileged organ, the liver harbors a unique and intricate immune microenvironment, which plays a dual role in pathogen clearance and chronicity. Kupffer cells (KCs), the primary resident macrophages in the liver, constitute the first line of defense in liver innate immunity and play complex and important roles in pathogen recognition, phagocytosis, and the regulation of liver inflammation and immune responses. The complement receptor of the immunoglobulin superfamily (CRIg) is a membrane receptor that is specifically expressed on KCs. It serves not only as a sentinel for the liver against pathogen invasion but also as a sophisticated regulator for maintaining immune homeostasis. As a key component of the liver’s immune system, CRIg can efficiently mediate the clearance of complement-opsonized particles, thereby playing multidimensional roles in pathogen clearance, antigen cross-presentation, and the establishment of immune tolerance, functioning as both a “pathogen catcher” and an “immune brake.” This review focuses on the CRIg molecule, detailing its mechanisms in the recognition and phagocytic clearance by KCs, and its subsequent impact on hepatic immune responses. Furthermore, we explored the potential involvement of CRIg in the pathological progression of diverse liver diseases, including persistent inflammation, fibrosis, and hepatocarcinogenesis. This synthesis provides novel insights into the immunopathology of liver diseases and establishes a theoretical foundation for developing CRIg-targeted therapeutic strategies. Full article

Prostate-specific membrane antigen (PSMA) is an essential zinc-dependent metalloprotease classified within the type II transmembrane protein family, often referred to as glutamate carboxypeptidase II (GCPII). PSMA is recognized as a particularly promising target for both the diagnosis and therapeutic intervention of prostate cancer. In this study, we designed and synthesized PSMA-targeted DOTA-loaded bimodal conjugate 11 with SulfoCy5 fluorescent dye, performed in vitro characterization, and analyzed biodistribution in vivo. At 40–100 nM concentrations, the resulting conjugate demonstrated reliable visualization of tumor cells, on par with the reference PSMA-SylfoCy5 compound. In vivo biodistribution analysis of [⁶⁸Ga]Ga-11 in mice demonstrated a reduction in renal accumulation in comparison with dye-free conjugate [⁶⁸Ga]Ga-10. The specificity of [⁶⁸Ga]Ga-11 for PSMA was confirmed in a murine LNCaP xenograft model: its effective accumulation in tumors and kidneys, as well as relatively rapid elimination from non-target tissues, make it a promising agent for PET imaging but not radionuclide therapy. Full article

Gold nanoparticles (AuNPs) have been extensively studied in cancer treatment research since they have special physicochemical characteristics such as facile surface functionalization with various chemical groups, low toxicity, favorable biocompatibility, and the ability to passively accumulate in tumors through the enhanced permeability and retention (EPR) effect. Prostate cancer cells exhibit an overexpression of the Prostate-Specific Membrane Antigen (PSMA), which therefore represents an ideal candidate for the development of nanoplatforms targeting PSMA overexpressed on these cells. Lutetium-177 (¹⁷⁷Lu) is a β-particle emitter with a half-life of 6.7 days. This radionuclide is very promising for the development of theranostic platforms as it emits β⁻ particles, which are suitable for therapy, and γ-photons, capable of SPECT imaging. The combination of ¹⁷⁷Lu with AuNPs functionalized with PSMA for targeted delivery offers a promising tool for both diagnosis and therapy of prostate cancer. In this study, we focused on the synthesis and in vitro evaluation of PSMA-targeted AuNPs radiolabeled with ¹⁷⁷Lu. The AuNPs were functionalized with the TADOTAGA chelator, which enables effective radiolabeling with the radiometal, as well as with a PSMA molecule, which comprises the PSMA targeting moiety (vehicle) of the nanoconstruct. Radiolabeling of the functionalized AuNPs with ¹⁷⁷Lu was fast and robust. Subsequent studies focused on the in vitro stability and cellular interaction with two prostate cancer cell lines with different PSMA expression levels, in both 2D and 3D cell cultures, to assess effective targeting. Results indicate that radiolabeled AuNPs exhibit selective interaction with PSMA-expressing cells and present a stronger in vitro cytotoxic effect when functionalized with the PSMA molecule, confirming their potential as theranostic agents and warranting further investigation in LNCaP tumor-bearing mice. Full article

Background: Rabies is a highly fatal zoonotic disease that causes approximately 59,000 human deaths worldwide each year. Current inactivated rabies vaccines require multiple doses and are associated with high costs. The full-length rabies virus glycoprotein (RVG), a membrane protein, exhibits substantial instability in its trimeric structure during recombinant expression. This instability makes it difficult to obtain high-purity, correctly folded antigens. Objectives: This study focuses on the preparation of a full-length recombinant RVG subunit vaccine candidate expressed in a glycoengineered Pichia pastoris system with mammalian-like glycosylation. Methods: The full-length RVG gene (including the transmembrane domain and cytoplasmic tail) from the Challenge Virus Standard-11 (CVS-11) strain was codon-optimized and inserted into the pPICZαA vector to construct the recombinant expression plasmid pPICZαA-RVG. The plasmid was transformed into glycoengineered Pichia pastoris X33-7 (low-mannose type) by electroporation for inducible expression. The target protein was purified by nickel affinity chromatography, anion-exchange chromatography, and Superdex-200 size-exclusion chromatography. The structural characteristics of the purified protein were analyzed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The purified antigen was formulated with the adjuvants AS03 or MF59. BALB/c mice (n = 5 per group) were immunized intramuscularly following a four-dose schedule (days 0, 7, 14, and 28). Antigen-specific IgG antibody titers were measured by ELISA, and neutralizing antibody titers were determined using the rapid fluorescent focus inhibition test (RFFIT). Results: Glycoengineered Pichia pastoris yeast strains expressing wild-type RVG (RVG-WT) or a mutant variant (RVG-M6: R84S, R199S, H270P, R279S, K300S, and R463S) were successfully constructed. The purified RVG antigen formed nanoparticles with an average particle size of approximately 75 nm. Immunized mice generated robust RVG-specific IgG responses, with titers reaching approximately 6.31 × 10⁵ for RVG-WT after the fourth immunization, compared to 3.16 × 10³ for RVG-M6 and 5.62 × 10³ for the RVG-WT-PEG control. Two weeks after the fourth immunization, RVG-WT formulated with AS03 or MF59 induced significant neutralizing antibody responses compared with the control group (p < 0.0001 and p < 0.01, respectively). The neutralizing antibody titers reached 1:79.43 in the AS03 group and 1:33.11 in the MF59 group, whereas the WT-PEG + AS03 control group showed a low titer of 1:3.72. In contrast, RVG-M6 formulated with MF59 failed to induce detectable neutralizing antibodies (1:3.02). Furthermore, RVG-WT + AS03 induced significantly higher neutralizing antibody responses than the WT-PEG + AS03 control group (p < 0.0001), and a significant difference was also observed between the RVG-WT + MF59 and RVG-M6 + MF59 groups (p < 0.01). Conclusions: The glycoengineered Pichia pastoris expression system successfully produced uniform full-length rabies virus glycoprotein nanoparticles with high purity. When formulated with the AS03 adjuvant, RVG-WT induced high-titer neutralizing antibodies in mice, suggesting a promising strategy for the development of recombinant subunit vaccines against rabies. However, this study is limited by the absence of challenge studies and validation in target animal species, which will be further investigated in future work. Full article

Purpose: Prostate-specific membrane antigen (PSMA) is a well-established molecular target in prostate cancer (PCa). Both radionuclide imaging and near-infrared fluorescence (NIRF) imaging offer high sensitivity for in vivo tumor detection. PSMA-targeted dual-modality probes integrating these two imaging techniques provide complementary preoperative and intraoperative tumor visualization, thereby improving surgical guidance in PCa. In this study, we aimed to develop a novel dual-labeled PSMA probe combining radioactive and fluorescent properties to achieve precise tumor delineation during radical prostatectomy (RP). Methods: A high-affinity PSMA-targeted fluorescent probe (PSMA-DF) was synthesized using solid-phase synthesis. Subsequent radiolabeling with the radionuclide [⁶⁸Ga]Ga yielded the successful generation of a dual-modal PSMA-targeted molecular probe, namely [⁶⁸Ga]Ga-PSMA-DF. The probe was systematically evaluated both in vitro and in vivo, and its safety profile was assessed through acute toxicity testing. Tumor-bearing nude mouse models were established using PSMA-positive 22Rv1 and PSMA-negative PC-3 PCa cell lines. Imaging performance, tumor-targeting specificity, and biodistribution of the probe were comprehensively evaluated using micro-PET imaging, in vivo fluorescence imaging, and biodistribution studies. Results: High-quality and high-purity PSMA-DF was successfully prepared, which exhibited excellent optical properties. Following radiolabeling with [⁶⁸Ga]Ga, a dual-modality radionuclide-fluorescence probe ([⁶⁸Ga]Ga-PSMA-DF) was successfully constructed. In vitro cellular uptake studies demonstrated that 22Rv1 cells had relatively high uptake of the probe, reaching 7.34 ± 0.55 IA%/10⁶ cells at 120 min. In contrast, PC-3 cells and blocked 22Rv1 cells displayed minimal uptake, confirming the specific targeting ability of the probe. In vivo evaluations were conducted on tumor-bearing mice using micro-PET/CT and NIRF imaging. The results revealed that [⁶⁸Ga]Ga-PSMA-DF achieved high specific tumor accumulation in 22Rv1 xenografts, with the peak tumor uptake (SUVmax = 1.748 ± 0.132) and tumor-to-muscle ratio (11.542 ± 1.511) observed at 120 min. Notably, high-contrast fluorescence imaging was also achieved at later time points, yielding a tumor-to-background ratio (TBR) of 6.559 ± 1.415 at 48 h. Notably, ex vivo biodistribution data were consistent with in vivo imaging findings. Conclusions: This preclinical study demonstrates that [⁶⁸Ga]Ga-PSMA-DF exhibits high and specific uptake in PCa models, supporting its potential as a dual-modality tracer for both PET/CT imaging and real-time intraoperative fluorescence guidance during PCa surgery. Full article