Search Results (1,887)

Background/Objectives: Neovascularization, defined as the sprouting of new blood vessels from pre-existing vasculature, is a critical pathological feature in ocular diseases such as pathological myopia and represents a leading cause of corneal vision loss. Vascular endothelial growth factor A (VEGFA) plays a pivotal role in endothelial cell proliferation, migration, survival by anti-apoptotic signaling, and vascular permeability. Dysregulation of VEGFA is closely linked to pathological neovascularization. Exosomes, nanosized phospholipid bilayer vesicles ranging from 30 to 150 nm, have emerged as promising gene delivery vehicles due to their intrinsic low immunogenicity, superior cellular uptake, and enhanced in vivo stability. This study aimed to investigate whether highly purified mesenchymal stem cell (MSC)-derived exosomes loaded with VEGFA siRNA labeled with FAM can effectively suppress pathological corneal neovascularization (CNV) via targeeted cellular transduction and VEGFA inhibition. Furthermore, we examined whether the therapeutic effect involves the modulation of the PI3K–Akt–Caspase-3 signaling axis. Methods: Exosomes purified by chromatography were characterized by electronmicroscopy, standard marker immunoblotting, and nanoparticle tracking analysis. In vitro, we assessed exosome uptake and cytoplasmic release, suppression of VEGFA mRNA/protein, cell viability, and apoptosis. In a mouse CNV model, we evaluated tissue reach and stromal retention after repeated intrastromal injections; anterior segment angiogenic indices; CD31/VEGFA immunofluorescence/immunoblotting; phosphorylated PI3K and Akt; cleaved caspase-3; histology (H&E); and systemic safety (liver, kidney, and spleen). Results: Exosomes were of high quality and showed peak efficacy at 48 h, with decreased VEGFA mRNA/protein, reduced viability, and increased apoptosis in vitro. In vivo, efficient delivery and stromal retention were observed, with accelerated inhibition of neovascularization after Day 14 and maximal effect on Days 17–19. Treatment reduced CD31 and VEGFA, decreased p-PI3K and p-Akt, and increased cleaved caspase-3. Histologically, concurrent reductions in neovascularization, inflammatory cell infiltration, and inflammatory epithelial thickening were observed, alongside a favorable systemic safety profile. Conclusions:VEGFA siRNA-loaded exosomes effectively reduce pathological CNV via a causal sequence of intracellular uptake, cytoplasmic release, targeted inhibition, and phenotypic suppression. Supported by consistent PI3K–Akt inhibition and caspase-3–mediated apoptosis induction, these exosomes represent a promising local gene therapy that can complement existing antibody-based treatments. Full article

Cancer stem cells (CSCs) represent a small but highly resilient tumor subpopulation responsible for sustained growth, metastasis, therapeutic resistance, and recurrence. Their survival is supported by aberrant activation of developmental and inflammatory pathways, including Wnt/β-catenin, Notch, Hedgehog, PI3K/Akt/mTOR, STAT3, and NF-κB, as well as epithelial–mesenchymal transition (EMT) programs and niche-driven cues. Increasing evidence shows that phytochemicals, naturally occurring bioactive compounds from medicinal plants, can disrupt these networks through multi-targeted mechanisms. This review synthesizes current findings on prominent phytochemicals such as curcumin, sulforaphane, resveratrol, EGCG, genistein, quercetin, parthenolide, berberine, and withaferin A. Collectively, these compounds suppress CSC self-renewal, reduce sphere-forming capacity, diminish ALDH⁺ and CD44⁺/CD24⁻ fractions, reverse EMT features, and interfere with key transcriptional regulators that maintain stemness. Many phytochemicals also sensitize CSCs to chemotherapeutic agents by downregulating drug-efflux transporters (e.g., ABCB1, ABCG2) and lowering survival thresholds, resulting in enhanced apoptosis and reduced tumor-initiating potential. This review further highlights the translational challenges associated with poor solubility, rapid metabolism, and limited bioavailability of free phytochemicals. Emerging nanotechnology-based delivery systems, including polymeric nanoparticles, lipid carriers, hybrid nanocapsules, and ligand-targeted formulations, show promise in improving stability, tumor accumulation, and CSC-specific targeting. These nanoformulations consistently enhance intracellular uptake and amplify anti-CSC effects in preclinical models. Overall, the consolidated evidence supports phytochemicals as potent modulators of CSC biology and underscores the need for optimized delivery strategies and evidence-based combination regimens to achieve meaningful clinical benefit. Full article

Background/Objectives: Mesenchymal stem cells (MSCs) are deemed to be a highly safe model for autologous and allogeneic cellular therapy, owing to their inherent lack of HLA-DR expression, immunomodulatory properties, homing ability, and plasticity allowing differentiation into different cell types. The interest in activating autophagic signaling in MSCs has recently grown due to its significant potential in maintaining stemness, enhancing paracrine signaling, and providing therapeutic benefits for cancer and neurodegenerative diseases. This study aimed to explore the impact of autophagy induction on enhancing the therapeutic potential of MSCs by maintaining their plasticity and to assess different induction agents. Methods: In this study, MSCs were first extracted from the fat tissue of Sprague–Dawley (SD) rats and characterized phenotypically and molecularly by their positive expression of stemness markers CD29, CD106, and CD44, and their negative expression of hematopoietic surface markers CD14, CD34, and CD45, using a flow cytometry approach. Isolated MSCs were then treated separately with two FDA-approved autophagy inducers: Lithium Chloride and Trehalose, following assessment of autophagy activity. Results: Treated MSCs showed significant increases in autophagic activity at both the transcriptional and translational levels. The successful induction of autophagy in MSCs was confirmed through the elevated expression of autophagy-related genes such as ATG3, ATG13, ATG14, P62, and ULK1. These data were confirmed by the significant upregulation in LC3 protein expression and the formation of autophagosomes, which was detected using a transmission electron microscope. Furthermore, the expression of Oct4, Sox2, and Nanog genes was significantly enhanced after treatment with Trehalose and Lithium Chloride compared with untreated control MSCs which may indicate an upregulation of pluripotency. Meanwhile, Lithium Chloride and Trehalose did not significantly induce cellular apoptosis, indicated by the Bax/Bcl-2 expression ratio, and significantly decreased the expression of the antioxidant markers SOD and GPx. Conclusions: Treatment of MSCs with Trehalose and, in particular, Lithium Chloride significantly activated autophagic signaling, which showed a profound effect in enhancing cells’ pluripotency, reinforcing the usage of treated MSCs for autologous and/or allogenic cellular therapy. However, further in vivo studies for activating autophagy in cellular grafts should be conducted before their use in clinical trials. Full article

Bone metastases mark a critical and often terminal phase in cancer progression, where disseminated tumor cells (DTCs) manage to infiltrate and exploit the complex microenvironments of the bone marrow. While most current therapies focus on the well-known late-stage “vicious cycle” of osteolysis, they often overlook the earlier stages, namely, tumor cell colonization and dormancy. During these early phases, cancer cells co-opt hematopoietic stem cell (HSC) niches, using them as sanctuaries for long-term survival. In this review, we bring together emerging insights that highlight a trio of underappreciated cellular players in this metastatic takeover: megakaryocytes, erythroid lineage cells, and perivascular stromal subsets. Far from being passive bystanders, these cells actively shape the metastatic niche. For instance, megakaryocytes and platelets go beyond their role in transport; they orchestrate immune evasion and dormancy through mechanisms such as transforming growth factor-β1 (TGF-β1) signaling and the physical shielding of tumor cells. In parallel, we uncover a distinct “erythroid-immune” axis: here, stress-induced CD71⁺ erythroid progenitors suppress T-cell responses via arginase-mediated nutrient depletion and checkpoint engagement, forming a potent metabolic barrier against immune attack. Furthermore, leptin receptor–positive (LepR⁺) perivascular stromal cells emerge as key structural players. These stromal subsets not only act as anchoring points for DTCs but also maintain them in protective vascular zones via CXCL12 chemokine gradients. Altogether, these findings reveal that the metastatic bone marrow niche is not static; it is a highly dynamic, multi-lineage ecosystem. By mapping these intricate cellular interactions, we argue for a paradigm shift: targeting these early and cooperative crosstalk, whether through glycoprotein-A repetitions predominant (GARP) blockade, metabolic reprogramming, or other niche-disruptive strategies, could unlock new therapeutic avenues and prevent metastatic relapse at its root. Full article

Polydopamine (PDA) surface coatings are widely used in biomedical engineering to enhance cell–substrate interactions; however, their effects on cancer-cell behavior remain unclear. In this study, we investigated how PDA-coated two-dimensional (2D) culture surfaces influence oncogenic traits of human prostate cancer (PC) cells in vitro. Using LNCaP, DU145, and PC3 cell lines, we found that PDA-coated substrates markedly increased the adhesion, migration, invasion, proliferation, and colony formation in a dose- and time-dependent manner. PDA exposure also induced epithelial–mesenchymal transition (EMT), upregulated cancer stem cell markers (CD44, CD117, CD133, Sox2, Oct4, and Nanog), and elevated expression of metastasis- and chemoresistance-associated molecules (MMP-2, MMP-9, MDR1, and MRP1). Mechanistically, PDA coatings enhanced integrin α₂β₁-associated cell adhesion, accompanied by increased focal adhesion kinase (FAK) phosphorylation and downstream activation of JNK signaling. Pharmacological inhibition of integrin α₂β₁ (BTT-3033), FAK (PF573228) and JNK (SP600125) effectively abrogated PDA-induced malignant phenotypes and restored chemosensitivity to cabazitaxel, cisplatin, docetaxel, curcumin, and enzalutamide. Collectively, these findings identify PDA-coated surfaces as a simple, efficient, and reductionist in vitro platform for studying adhesion-mediated signaling and phenotypic plasticity in PC cells, while acknowledging that further validation in three-dimensional (3D) and patient-derived models will be required to establish in vivo relevance. Full article

Bioactive natural products (NPs) may play a critical role in cancer progression by targeting nucleic acids and a wide array of proteins, including enzymes. Furthermore, a large number of derivatives (NPDs), including semi-synthetic products and pharmacophores from NPs, have been developed to enhance the solubility and stability of NPs. Acute myeloid leukemia (AML) is a poor-prognosis hematologic malignancy characterized by the clonal accumulation in the blood and bone marrow of myeloid progenitors with high proliferative capacity, survival and propagation abilities. A number of potential pathways and targets have been identified for development in AML, and include, but are not limited to, Fms-like tyrosine kinase 3 (FLT3) and isocitrate dehydrogenases resulting from genetic mutations, BCL2 family members, various signaling kinases and histone deacetylases, as well as tumor-associated antigens (such as CD13, CD33, P-gp). By targeting nucleic acids, FLT3 or CD33, several FDA-approved NPs and NPDs (i.e., cytarabine, anthracyclines, midostaurin, melphalan and calicheamicin linked to anti-CD33) are the major agents of upfront treatment of AML. However, the effective treatment of the disease remains challenging, in part due to the heterogeneity of the disease but also to the involvement of the bone marrow microenvironment and the immune system in favoring leukemic stem cell persistence. This review summarizes the current state of the art, and provides a summary of selected NPs/NPDs which are either entering or have been investigated in preclinical and clinical trials, alone or in combination with current chemotherapy. With multifaceted actions, these biomolecules may target all hallmarks of AML, including multidrug resistance and deregulated metabolism. Full article

Macrophages play a crucial role in regulating immune responses, inflammation, and tissue repair. Depending on environmental cues, they polarize into pro-inflammatory M1 or anti-inflammatory, pro-regenerative M2 phenotypes. Extracellular vesicles (EVs) derived from mesenchymal stem/stromal cells (MSCs) have emerged as key mediators of intercellular communication and immune modulation. This study investigates the effects of matrix-bound vesicles (MBVs) and small extracellular vesicles (sEVs) derived from human umbilical cord MSCs (UC-MSCs) on human monocyte-derived macrophages (MDMs) in vitro. Both MBVs and sEVs reduced pro-inflammatory activation of M1 macrophages, downregulating the expression of CXCL10 and CD86 while increasing the M2 marker CD206. MBVs exerted a stronger suppressive effect on M1 MDM phenotype markers as well as on STAT1, STAT2, and IRF9 mRNA levels in M1 macrophages, indicating the inhibition of the JAK/STAT1 signaling pathway involved in the pro-inflammatory activation of macrophages. Functionally, both vesicle types enhanced phagocytosis of FITC-labeled E. coli by M1 and M0_GM macrophages, promoting a shift toward an M2-like phenotype. Moreover, MBVs and sEVs attenuated reactive oxygen species (ROS) production, with sEVs showing a more pronounced effect both on ROS generation and on the expression of NOX2 complex subunits (p47^phox, p67^phox) in M1 macrophages. These findings demonstrate that MBVs and sEVs from UC-MSCs possess distinct yet complementary immunomodulatory and antioxidant properties on MDMs, suggesting their potential as promising cell-free therapeutic agents for inflammatory and degenerative diseases. Full article

Human cytomegalovirus (HCMV) infection is a significant complication in transplant recipients. Following HCMV reactivation, the recovery of T-cell responses serves as a key indicator of protection from HCMV disease. This study aimed to assess the HCMV-specific CD4⁺ and CD8⁺ T-cell responses and their cytokine production (IFNγ, TNFα, IL2) against various HCMV proteins (IE-1, pp65, gB, gH/gL/pUL128L) in solid organ transplant recipients (SOTRs) and hematopoietic stem cell transplant recipients (HSCTRs) with active HCMV infection. The cohort consisted of 16 SOTR and 16 HSCTR categorized into two groups: (i) Controllers, who spontaneously controlled the infection, and (ii) Non-Controllers, who required antiviral treatment. T-cell responses were analyzed following stimulation with peptide pools and intracellular cytokine staining. Prior to transplantation, all patients exhibited a significantly higher frequency of CD4⁺ T cells specific to pp65 compared to gH and gL/pUL128L. During the peak of infection, T-cell frequencies across all peptides were similar, but at infection resolution, the frequency of pp65 and gB-specific CD4⁺IFNγ⁺ T cells was significantly higher than gL/pUL128L. Additionally, pp65 and IE-1-specific CD8⁺IFNγ⁺ T-cell responses were significantly greater than those against gH and gL/pUL128L at the resolution of infection. Notably, Controllers exhibited significantly higher frequencies of monofunctional pp65-specific T cells, particularly in CD8⁺ T cells producing IFNγ and TNFα. The response to pp65, especially IFNγ production, may serve as a key marker for identifying patients capable of controlling HCMV infection. Full article

Exosomes are nanoscale extracellular vesicles that mediate intercellular communication by transporting microRNAs, proteins, and lipids. Generated through Endosomal Sorting Complex Required for Transport (ESCRT)-dependent mechanisms or ESCRT-independent pathways, exosomes are released when multivesicular bodies fuse with the plasma membrane. The ESCRT-dependent pathway involves sequential protein complexes (ESCRT-0, I, II, III) that recognize and sort ubiquitinated cargo, induce membrane budding, and facilitate vesicle scission. In contrast, the ESCRT-independent pathway relies on membrane lipids such as ceramide and proteins like tetraspanins (CD9, CD63, CD81) to promote vesicle formation without ESCRT machinery. Furthermore, post-translational modifications, including ubiquitination, sumoylation, and phosphorylation, further serve as molecular switches, modulating the affinity of ESCRT complexes or cargo proteins for membrane domains and affecting ILV formation rates. In reproductive medicine, exosomes regulate oocyte maturation, embryo–endometrial crosstalk, placental development, and maternal–fetal communication. Altered exosomal signaling contributes to obstetric complications, including preeclampsia, gestational diabetes mellitus, and preterm birth, whereas distinct exosomal miRNA signatures serve as potential diagnostic biomarkers. In gynecology, dysregulated exosomes are implicated in endometriosis, polycystic ovary syndrome, premature ovarian insufficiency, and gynecological malignancies. In contrast, mesenchymal stem cell-derived exosomes show therapeutic promise in restoring ovarian function and enhancing fertility outcomes. The distinctive molecular profiles of circulating exosomes enable minimally invasive diagnosis, while their biocompatibility and ability to cross biological barriers position them as vehicles for targeted drug delivery. Characterization of accessible data provides non-invasive opportunities for disease monitoring. However, clinical translation faces challenges, including standardization of isolation protocols, establishment of reference ranges for biomarkers, and optimization of therapeutic dosing. This review summarizes exosome biogenesis, characterization methods, physiological functions, and clinical applications in obstetrics and gynecology, with an emphasis on their diagnostic and therapeutic potential. Future directions include large-scale biomarker validation studies, engineering approaches to enhance exosome targeting, and integration with precision medicine platforms to advance personalized reproductive healthcare. Full article

Recent studies support that hematopoietic stem cell (HSC)-derived myeloid dendritic cells, monocytes/macrophages (Mo/Mϕ), and osteoclast precursors (OCps) share common progenitor(s) during development. This occurs mainly through receptor activator of NF-κB ligand (RANKL) signaling via its cytoplasmic adaptor protein complex (TRAF6) to subsequent osteoclastogenesis for bone loss and/or remodeling. Presently, mounting new evidence suggests that erythro-myeloid progenitor (EMP)-derived macrophages (Mϕ) and HSC-derived monocytes (Mo) produce embryonic, fetal, and postnatal OCp pools (i.e., primitive OCp), pinpointing a complex network of multiple OCp developmental origins. However, their ontogenic developments, lineage interactions, and contributions to the alternative osteoclastogenesis—in contrast to overall bone remodeling or loss—remain elusive. Interestingly, studies have also elucidated the contributions of immature CD11c⁺ myeloid DC-like OCps to osteoclastogenesis, with or without the classical so-called Mo/Mϕ-derived OCp subsets, and described that CD11c⁺ myeloid DCs (mDCs) develop into functionally active OCs; meanwhile, the cytokine TGF-β mediates a stepwise regulation of de novo immature mDCs/OCps through distinct crosstalk(s) with IL-17, an unrecognized interaction featuring TRAF6^(−/−)CD11c⁺ mDDOCps that coexist and proficiently colocalize in the local environment to drive a bona fide route for alternative osteoclastogenesis in vivo. Collectively, new findings—critically hinged on progenitor osteoclastogenic pathways (primitive OCps, mDCs/OCps, osteomorphs, etc.) and involving classical and/or alternative routes to inflammation-induced bone loss—are discussed via the illustrated schemes. This review highlights plausible ontogenic vs. principal or alternative developmental paths and their consequential downstream effects. Full article

Background/Objectives: Menstrual blood, a periodic uterine discharge, represents a non-invasive source for an indication of the functional status of the endometrium. While menstrual blood-derived stem cells have been extensively characterized and menstrual blood is considered a diagnostic material for the analysis of gynecologic pathology in research studies, it is not routinely used in clinical settings. To develop novel noninvasive diagnostic tools for endometrial status assessment, we aimed to characterize the morphological and molecular markers of menstrual blood. Methods: Menstrual blood samples were obtained from healthy volunteers and characterized macroscopically and microscopically using smears (May-Grunwald-Giemsa staining), confocal microscopy, and imaging flow cytometry (cluster of differentiation [CD]90, CD45, fibrin). Clot dissociation was performed to analyze the cellular composition of clots. Results: We morphologically characterized menstrual blood cells and identified three uterine-derived cells and cell cluster types (endometrial stromal, endometrial epithelial, and vaginal epithelial). Additionally, we confirmed the specificity of CD90 for endometrial stromal cell populations, which were separately characterized in the supernatant and menstrual blood clots using light and confocal microscopy, and we analyzed the composition of the menstrual blood supernatant and dissociated clots using imaging flow cytometry. Conclusions: The results of this study may serve as a foundation for the development of new non-invasive diagnostic tools for endometrial pathology for the potential support or replacement of highly invasive procedures, such as diagnostic dilation and curettage. Full article

The National Institute of Standards and Technology (NIST) is developing analytical methods to characterize extracellular vesicles (EVs) to support the urgent need for standardized EV reference materials (RMs). This study used orthogonal techniques, cryogenic electron microscopy (Cryo-EM), particle tracking analysis (PTA), asymmetrical flow field-flow fractionation (AF⁴), and microfluidic resistive pulse sensing (MRPS), to evaluate particle size distributions (PSDs) and particle number concentrations (PNCs) of human mesenchymal stem cells (MSCs) and LNCaP prostate cancer cell EVs. Proteomic profiles were assessed by mass spectrometry (MS), and microRNA (miRNA) content of LNCaP EVs was evaluated by small RNA-seq at two independent laboratories. A commercial green fluorescent protein exosome served as a control, except in Cryo-EM, proteomic, and miRNA analyses. Cryo-EM, regarded as the gold standard for morphological resolution, served as PSD reference. PSDs from all methods skewed larger than Cryo-EM, with MRPS closest, AF⁴ most divergent, and PTA intermediate with broader distributions. All techniques reported broad PSDs (30 nm to >350 nm) with PNCs decreasing with increasing particle size, except for AF⁴. Quantitative discrepancies in PNCs reached up to two orders of magnitude across methods and cell sources. MS identified global and EV-specific proteins, including syntenin-1 and tetraspanins CD9, CD63, and CD81. RNA-seq revealed notable inter-laboratory variation. These findings highlight the variability across measurement platforms and emphasize the need for reproducible methods to support NIST’s mission of developing reliable EV reference materials. Full article

We present a detailed, xeno-free protocol for the rapid differentiation of human induced pluripotent stem cells (hiPSCs) into microglia using the well-characterized KOLF2.1J reference line. This system employs doxycycline-inducible expression of six transcription factors (6-TF), stably integrated into the CLYBL safe harbor locus, to drive uniform microglial differentiation within two weeks. Building upon an established transcription factor-driven approach, our protocol includes key optimizations for KOLF2.1J, including culture on Laminin-521 to support xeno-free conditions. The resulting i-Microglia exhibit hallmark features of mature microglia, including expression of P2RY12, loss of the pluripotency marker SSEA4, phagocytic activity, and upregulation of immune markers (e.g., CD80, CD83) upon LPS stimulation. We also demonstrate compatibility with co-culture systems using iPSC-derived neurons. Additionally, we describe a modification of the line to include a constitutive mCherry reporter integrated into the SH4-2 safe harbor locus, enabling fluorescent tracking of microglia in mixed cultures or in vivo. This protocol provides a reproducible and scalable platform for generating functional human microglia from a widely used hiPSC line, supporting applications in brain tumors and disease modeling, neuroinflammation research, and therapeutic screening. Full article

Kynurenic acid (KYNA), a small molecule derived from the tryptophan–kynurenine pathway, can readily diffuse across biological membranes and act as an endogenous ligand for receptors such as the aryl hydrocarbon receptor (Ahr). While KYNA dysregulation is implicated in neurodegenerative disorders, the role of the KYNA–Ahr-IL-6 axis in MSC proliferation and differentiation remains poorly defined. We investigated the impact of KYNA on murine bone marrow-derived MSCs (BM-MSCs) at various concentrations (10–200 μM) and time points (8–48 h). The BM-MSC phenotype was assessed via flow cytometry; proliferation, via cell counting; and the gene expression of Ahr, Cyp1a1, Cyp1b1, and Il-6, via quantitative real-time PCR. Multipotency was evaluated through adipogenic, osteogenic, and chondrogenic differentiation assays with histochemical confirmation. KYNA significantly upregulated Ahr mRNA expression. Among the tested concentrations, 100 μM KYNA induced the highest Ahr expression (~19.1 ± 1.5-fold greater than that of the untreated controls, p < 0.005). Notably, 10 and 50 μM KYNA caused moderate induction, whereas compared with 100 μM KYNA, 200 μM did not further increase expression. In addition, KYN treatment increased Cyp1a1, Cyp1b1, and Il-6 expression, with increases of ~64.6 ± 4.5-fold, ~43.6 ± 2.3-fold, and ~41.6 ± 1.2-fold, respectively. Compared with no treatment, 100 µM KYNA enhanced BM-MSC proliferation by 1.210 ± 0.02, 1.189 ± 0.03, and 1.242 ± 0.02-fold across passages P3, P4, and P5, respectively (p < 0.05), without altering Sca-1, CD90, or CD45 expression or impairing trilineage differentiation potential. KYNA may activate the AHR–IL-6 signaling axis to promote BM-MSC expansion. This controlled proliferative effect, without loss of phenotypic or functional integrity, highlights the pharmacological potential of KYNA as a small-molecule modulator for stem cell-based therapies. Full article

The immunoregulatory effects of probiotics have been widely studied, particularly in maintaining immune balance. Conventional in vitro functional screening of probiotics relies on fresh donor-derived primary immune cells, which often exhibit significant inter-individual and temporal variability, limiting reproducibility and interpretation. As an alternative, human-induced pluripotent stem cell (iPSC)-derived dendritic cells were co-cultured with five probiotic strains in the current study to evaluate their immunomodulatory interactions. To assess whether cytokines produced by probiotic-stimulated dendritic cells can influence T cell differentiation, human CD4⁺ T cells were exposed to the conditioned medium derived from co-cultures. Enzyme-linked immunosorbent assay results demonstrated that iPSC-derived dendritic cells secreted cytokines at distinct concentrations in response to different probiotic strains, suggesting that these cells can distinguish between different microbial stimuli, and supporting their use in functional probiotic screening. Among the five strains tested, Lactiplantibacillus plantarum LPA-56, Limosilactobacillus reuteri RU-23, and Lactobacillus fermentum Fem-99 induced cytokine production levels that promoted the differentiation of the human CD4⁺ T cells into regulatory T cells. These findings demonstrate that iPSC-derived dendritic cells have immunomodulatory potential, are reliable for in vitro screening of probiotics, and offer a promising strategy for selecting potent immunoregulatory probiotic candidates. Full article