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The immunomodulatory role of monocytes is essential for tissue healing and can influence the osseointegration of implanted materials. Properties such as the surface structure, hydrophilicity, and roughness of the implanted materials can modulate monocyte–macrophage function. In this study, we characterized material-hydrogenated TiO2 nanotubes (H-TNT) with superhydrophilic surfaces to investigate the effect of H-TNT on macrophage polarization and osseointegration. H-TNT were prepared by anodic oxidation and hydrogenation and used in the experimental group, while TNT and smooth pure Ti were employed in the control groups. RAW264.7 cells were selected to observe the immunomodulatory effect of these samples. The cell morphology was observed via scanning electron microscopy, and cytokine expression was detected using an enzyme-linked immunosorbent assay and immunofluorescence staining. After 24 hr of cultivation, the macrophage-conditioned medium was collected and used for indirect coculture with MC3T3-E1 cells. The morphology of MC3T3-E1 cells was observed using fluorescence staining. Cell adhesion and proliferation were measured using the Cell Counting Kit-8 assay. Alkaline phosphatase activity measurement, alizarin red staining, calcium quantification, and reverse transcription polymerase chain reaction were performed to assess the osteogenic differentiation of MC3T3-E1 cells. The results showed that H-TNT promoted the M2-type polarization of macrophages, which in turn influenced the adhesion, proliferation, and osteogenic differentiation of MC3T3-E1 cells. These materials can serve as useful candidates for bone implants because they activate macrophages to produce a favorable osteoimmunomodulatory microenvironment. [ABSTRACT FROM AUTHOR]

• RAN promoted the polarization of macrophages towards M1 by activating the PI3K/Akt2/NF-κB signaling pathway. • p-Akt2 can enhance the endocytosis of macrophages by regulating GSK3β/Dynamin1 pathway. • RAN as adjuvant could effectively increase the differentiation of Th1 cells after M1 polarization. • RAN could enhance the killing function of CTL to inhibit tumor growth and improve survival rate as adjuvant tumor vaccine. Adjuvants are an indispensable component of vaccines, but there are few adjuvants for human vaccines. H2 receptor blockers, inhibiting gastric acid secretion, have immune enhancement effects. Ranitidine (RAN) is a water-soluble H2 receptor blocker, and whether it has an immune-enhancing effect is still unknown. In this study, flow cytometry, western blotting, and immunofluorescence methods were used to analyze whether RAN could activate macrophage polarization to the M1 phenotype in vivo and in vitro. Here, we found that the M1 inflammatory cytokine levels and surface markers in RAW264.7 cells were upregulated by NF-κB activation, possibly through the PI3K-Akt2 signaling pathway, after RAN treatment. Endocytic function was also enhanced by feedback regulation of Akt2/GSK3β/Dynmin1 signaling. Furthermore, to evaluate the adjuvant function of RAN, we used OVA plus RAN as a vaccine to inhibit the growth of B16-OVA tumors in mice. We also found that in the RAN adjuvant group, macrophage polarization to M1, Th1 cell differentiation, and cytotoxic T lymphocyte (CTL) activation were significantly upregulated. The tumor growth of mice was inhibited, and the survival rate of mice was significantly improved. This study provides new evidence for the mechanism by which RAN activates the immune response and is expected to provide a new strategy for the research and development of tumor vaccine adjuvants. [ABSTRACT FROM AUTHOR]

• BAI treatment delayed the onset of EAE, alleviate clinical symptoms, demyelination and inflammatory cell infiltration. • BAI inhibited the overactivation of M1 microglia/macrophages in vivo and in vitro, significantly decreased the expression of proinflammatory cytokines in M1 microglia/macrophages. • BAI has the binding ability to the SH2 domain of STAT1, and leaved P-STAT1 in the cytoplasm rather than transferred to the nucleus during inflammatory stimulation. Microglia/macrophage polarization modulation plays a key role in the pathogenesis of multiple sclerosis (MS)/experimental autoimmune encephalomyelitis (EAE). M1 microglia/macrophages secrete a variety of cytokines that cause inflammation and facilitate demyelination in the central nervous system (CNS). Baicalein (5,6,7-trihydroxyflavone, C 15 H 10 O 5 , BAI), a natural flavonoid isolated from the roots of the traditional Chinese medicine Scutellaria baicalensis Georgi, has been suggested to have a wide range of biological effects, including antioxidant, anti-inflammatory, and neuroprotective properties. In this study, flow cytometry, Western blotting, immunofluorescence and other methods were used to investigate whether BAI could reduce the demyelination and inflammatory response of the spinal cord in EAE mice induced by MOG 35-55 and affect the polarization of spinal microglia/macrophages. Our results showed that BAI treatment delayed the onset of EAE and alleviated clinical symptoms, demyelination and inflammatory cell infiltration. Meanwhile, BAI inhibited the overactivation of M1 microglia/macrophages in vivo and in vitro, significantly decreased the expression of proinflammatory cytokines in M1 microglia/macrophages, and inhibited the activation of STAT1. Subsequently, molecular docking, pull-down and immunofluorescence experiments confirmed that BAI has the ability to bind to the SH2 domain of STAT1 and that BAI colocalizes with p-STAT1 in the cytoplasm rather than being transferred to the nucleus during inflammatory stimulation. This study showed that BAI might inhibit the polarization of microglia/macrophages to the M1 phenotype in EAE mice by targeting STAT1. This new discovery lays a theoretical and experimental foundation for the clinical application of BAI in the treatment of MS. [ABSTRACT FROM AUTHOR]

Zebrafish Fish-egg lectin (zFEL) has been identified and proved to be a maternal factor with antibacterial and opsonic ability in fishes. In this study, we found that zFEL was capable of enhancing the phagocytosis of the bacteria by macrophages of mouse (RAW264.7 and mouse peritoneal macrophages), suggesting a cross-species function of zFEL in higher animals. Further studies showed that zFEL can active the antigen presentation ability by up-regulating the expression of CD80, CD86 and MHC II. Meanwhile, zFEL also promoted the polarization of macrophages to M1-type, which was confirmed by the increase of cytokines TNF-α and IL-6. The expression of p38 gene was up-regulated in macrophages preincubated with zFEL. Taken together, zFEL appears opsonic function in mammal macrophages and has potential application in immunomodulation. • Cross-species opsonic activity is found by zebrafish fish-egg lectin (zFEL) on mouse macrophages. • zFEL can up-regulate the expression of CD80, CD86 and MHC II on macrophages. • zFEL promotes the polarization of macrophages to M1-type. [ABSTRACT FROM AUTHOR]