Construction, Phenotypic Characterization, and Immunomodulatory Function Study of BMSC-Macrophage Hybrid in vitro

ObjectiveThe aim of our study was to integrate bone marrow-derived stem cells (BMSCs) with macrophages and to investigate the performance of this hybrid in IgG clearance, immunosuppression, and the mitigation of inflammatory injury. MethodsBMSCs and RAW264.7 cells were fused through transient transfection using the COVID-19 spike glycoprotein and human angiotensin-converting enzyme 2 (hACE2), respectively. The resulting hybrids were purified using magnetic sorting, and their characteristics were evaluated by examining morphology, glucose uptake rates, phagocytic capacity, cytoskeletal morphology, and the levels of Fc{gamma} receptors, as well as anti-inflammatory, antioxidant, adhesion, and complement inhibitory factors. The IgG clearance capability of the hybrids was assessed by measuring internalization efficiency and infiltration into renal organoids. Additionally, the reparative effects of the hybrids were evaluated using doxorubicin-treated MPC5 damage models. Live cell imaging techniques were employed to investigate the interactions between the hybrids and immature dendritic cells (iDCs). Hybrid-derived nanovesicles were isolated, and their abilities to target IgG and clear IL-6 were evaluated using immunofluorescence and ELISA. Furthermore, chloroplasts and C-dots were co-incubated with the hybrids, and their benefits were assessed by measuring cell viability, oxygen content, ROS levels, mitochondrial function, and the levels of anti-inflammatory, antioxidant, and pro-repair factors. A scratch assay was conducted to determine the impact of chloroplast transplantation on the migration ability of 3T3 cells. ResultsHigh-purity hybrids were successfully produced that cleared IgG while maintaining their anti-inflammatory and antioxidant effects. They promoted the recovery of podocyte injury through vesicular and mitochondrial delivery, as well as efferocytosis. Furthermore, the hybrids inhibited iDCs primarily through migrasomes, intercellular nanomicrotubule connections, and phagocytosis. The derived nanovesicles were capable of residing in IgG-enriched regions and adsorbing IL-6. Interestingly, the transplanted chloroplasts enabled the hybrids to utilize light energy to enhance their antioxidant capacity and promote the migration of 3T3 cells, which contributes to wound repair. Subsequently, the loading of C-dots was beneficial for enhancing resistance to oxidative damage. ConclusionsOur results suggest that hybrids-mediated therapy is a new and creative therapeutic approach for managing immune-mediated nephropathies.Hybrids demonstrated effective immunomodulatory and promoted injury recovery. The derived nanovesicles have the potential to alleviate the inflammatory burden at sites of antibody immune complex deposition. Additionally, the incorporation of chloroplasts and C-dots enhanced the hybrids adaptability to ischemic-hypoxic microenvironments.