Search Results (104)

Adoptive cell therapies have transformed the treatment landscape for hematologic malignancies. Yet, translation to solid tumors remains constrained by antigen heterogeneity, an immunosuppressive tumor microenvironment (TME), and poor persistence of conventional CAR-T cells. In response, innate immune cell platforms, particularly chimeric antigen receptor–engineered natural killer (CAR-NK) cells and chimeric antigen receptor–macrophages (CAR-MΦ), have emerged as promising alternatives. This review summarizes recent advances in the design and application of CAR-NK and CAR-MΦ therapies for solid tumors. We highlight key innovations, including the use of lineage-specific intracellular signaling domains (e.g., DAP12, 2B4, FcRγ), novel effector constructs (e.g., NKG7-overexpressing CARs, TME-responsive CARs), and scalable induced pluripotent stem cell (iPSC)-derived platforms. Preclinical data support enhanced antitumor activity through mechanisms such as major histocompatibility complex (MHC)-unrestricted cytotoxicity, phagocytosis, trogocytosis, cytokine secretion, and cross-talk with adaptive immunity. Early-phase clinical studies (e.g., CT-0508) demonstrate feasibility and TME remodeling with CAR-MΦ. However, persistent challenges remain, including transient in vivo survival, manufacturing complexity, and risks of off-target inflammation. Emerging combinatorial strategies, such as dual-effector regimens (CAR-NK⁺ CAR-MΦ), cytokine-modulated cross-support, and bispecific or logic-gated CARs, may overcome these barriers and provide more durable, tumor-selective responses. Taken together, CAR-NK and CAR-MΦ platforms are poised to expand the reach of engineered cell therapy into the solid tumor domain. Full article

Refractory apical periodontitis (RAP), a persistent infection after root canal treatment, still has no effective treatment. Enterococcus faecalis (E. faecalis) and Fusobacterium nucleatum (F. nucleatum) are frequently detected in the lesion. We previously found that coaggregation altered gene expression of E. faecalis and F. nucleatum and promoted immune evasion by suppressing pro-inflammatory cytokine secretion of macrophages (Mφs) while sustaining low-grade inflammation. In this study, we further investigated the synergistic effect of coaggregated E. faecalis and F. nucleatum on modulating Mφ immune and metabolic responses. Using transmission electron microscope, flow cytometry, RNA-seq and functional assays, we demonstrated that coaggregated E. faecalis and F. nucleatum caused nuclear shrinkage and increased mitochondria in Mφ while inducing M1 polarization, ROS production, and lipid accumulation of Mφ. The key driver genes causing the difference between single species-infected and coaggregated bacteria-infected Mφ mainly included IFN-stimulated genes and genes related to the chemokine signaling pathway. These findings indicate that the synergism of E. faecalis and F. nucleatum can regulate the immune and metabolic response of Mφ, offering novel insights into therapeutic targets for refractory apical periodontitis. Full article

Probiotics play a pivotal role in animal production by promoting growth, enhancing gut health, and modulating immune responses. Bacillus subtilis, a widely utilized probiotic, forms robust spores that exhibit exceptional resistance, making it ideal for feed applications. While B. subtilis spores have been shown to stimulate innate immune signaling, the specific contributions of spore coat proteins to immune modulation remain poorly characterized. In this study, we investigated the immunostimulatory effects of spores deficient in six key coat proteins: SpoIVA, SafA, CotE, CotX, CotZ, and CgeA. These proteins are essential for the assembly and structural integrity of the spore’s multi-layered coat, and are involved in recruiting other coat components. Deletion of these genes result in defects in spore coat architecture, potentially altering spore–host interactions. Using porcine alveolar macrophages (MΦ3D4/2), we assessed cytokine responses to each mutant strain. Our findings demonstrate that the absence of specific structural proteins significantly impacts immune activation, particularly through Toll-like receptor pathways. This work provides novel insights into the immunomodulatory functions of spore coat proteins and lays the foundation for the rational design of next-generation B. subtilis-based probiotics with enhanced immunological properties for agricultural applications. Full article

The COVID-19 pandemic, caused by SARS-CoV-2, has significantly affected global health, with severe inflammatory responses leading to tissue damage and persistent symptoms. Macrophage-derived extracellular vesicles (EVs) are involved in the modulation of immune responses, but their involvement in SARS-CoV-2-induced inflammation and senescence remains unclear. Triggering receptors expressed on myeloid cell-1 (TREM-1) are myeloid cell receptors that amplify inflammation, described as a biomarker of the severity and mortality of COVID-19. This study investigated the composition and effects of macrophage-derived EVs stimulated by SARS-CoV-2 (MφV-EVs) on the recipient cell response. Our results, for the first time, show that SARS-CoV-2 stimulation modifies the cargo profile of MφV-EVs, enriching them with TREM-1 and miRNA-155 association, along with MMP-9 and IL-8/CXCL8. These EVs carry senescence-associated secretory phenotype (SASP) components, promote cellular senescence, and compromise antibacterial defenses upon internalization. Our findings provide evidence that MφV-EVs are key drivers of inflammation and immune dysfunction, underscoring their potential as therapeutic targets in COVID-19. Full article

Mesenchymal stem cells (MSCs) have been widely used for the treatment of autoimmune and inflammatory diseases due to their pluripotent differentiation potential and immunomodulatory function. Macrophage (Mφ) polarization also acts an essential and central role in regulating inflammation, basically the dynamic balance of pro-inflammatory M1-like (M1φ) and anti-inflammatory M2-like macrophages (M2φ), affecting the occurrence and progression of inflammatory diseases. Since a pivotal molecular crosstalk between MSCs and Mφ has been elucidated using in vitro and in vivo preclinical studies, we presume that the mesenchymal stem cell/macrophages axis (MSC/Mφ axis) acts an important role in pathophysiological mechanisms of inflammatory diseases and should be the potential therapeutic target. However, the crucial effects of EVs as intercellular communicators and therapeutic agents in the MSC/Mφ axis remains explorable. Therefore, this review elaborated on the mechanisms of EVs mediating the MSC/Mφ axis regulating inflammation in-depth, hoping to provide more references for related research in the future. Full article

Background: Personalized cancer vaccines based on tumor neoantigens show great potential in cancer immunotherapy due to their high safety and specificity. However, it is inherently difficult to realize the efficiently targeted delivery of personalized cancer vaccines to antigen-presenting cells (APCs). Methods: This study aimed to address these challenges by developing and evaluating a personalized cancer vaccine based on antibody–antigen complexes, which was designed to enhance antitumor effects by increasing the utilization of tumor neoantigens by APCs. Mice were immunized with a carrier protein, keyhole limpet hemocyanin (KLH), to induce the production of antibodies against KLH. Subsequently, mice were immunized with KLH loaded with tumor neoantigens and the immunoadjuvant CpG ODN and underwent immunological analysis to evaluate the immune and antitumor effects. Results: The results showed that preimmunization with KLH could promote the uptake of the personalized KLH-based tumor vaccine, which was enhanced by dendritic cells (DCs) and macrophages (Mφs), by strengthening the T-cell immune responses to tumors. Conclusions: Collectively, this work provides a new idea for the targeted delivery of personalized cancer vaccines. Full article

Background/Objectives. Psoriasis is a common chronic skin inflammatory disorder pathogenetically associated with genetic, environmental, and immunological factors. The hallmarks of psoriatic lesions include sustained inflammation related to alterations in the innate and adaptive immune response, uncontrolled keratinocyte proliferation, differentiation, and death, as well as dysregulated crosstalk between immune cells and keratinocytes. In search of novel therapeutic strategies based on the use of natural products and dietary components to combine to the available conventional and innovative therapeutics, we explored the anti-inflammatory, antioxidant, and immunomodulatory activities of Curcumin (CU)-based solid lipid nanoparticles (SLNs) carrying the omega-3 fatty acid linolenic acid (LNA) in an in vitro model of psoriasis that had been previously constructed and characterized by us. Methods. This in vitro model consists of differentiated in vitro THP-1 macrophages (Mφs) and NCTC-2544 keratinocytes exposed or not to conditioned medium (CM) from Mφs treated with the Toll-like receptor-7 ligand imiquimod (IMQ). Results. In Mφs, the treatment with CU-LNA-SLNs inhibited the IMQ-induced expression of proinflammatory cytokines (IL-23, IL-8, IL-6: 43%, 26.5% and 73.7% inhibition, respectively, vs IMQ-treated Mφs), as well as the hyperproliferative response (12.8% inhibition vs IMQ-treated Mφs) and the increase in cell death observed in keratinocytes treated with Mφ-derived CM (64.7% inhibition). Moreover, in the same conditions, CU-LNA-SLNs reverted to control levels of the increased keratinocyte expression of two markers of ferroptosis, a form of death recently involved in the pathogenesis of psoriasis (TFRC and MDA: 13.4% and 56.1% inhibition, respectively). Conclusions. These results suggest that CU-LNA-SLNs could inhibit psoriatic inflammation, as well as the hyperproliferation and death of keratinocytes in psoriatic lesions, and could be considered as a new possible therapeutic strategy for psoriasis to be further evaluated for the topic treatment of psoriatic skin in vivo. Full article

Background: A hallmark of cancer is the presence of an immunosuppressive tumor microenvironment (TME). Immunosuppressive M2 macrophages (MΦs) in the TME facilitate escape from immune surveillance and promote tumor growth; therefore, TME-induced immunosuppression is a potent immunotherapeutic approach to treating cancer. Methods: Cancer cell-secreted proteins were detected by using liquid chromatography–mass spectrometry (LC-MS). Neutralizing antibodies (nAbs) were used to assess which proteins were involved in MΦs polarization and differentiation. The protein–protein interaction was characterized using co-immunoprecipitation and immunofluorescence assays. Cancer-secreted heat shock protein 70 (Hsp70) protein was quantified using an enzyme-linked immunosorbent assay (ELISA). MΦ polarization and tumor growth were assessed in vivo with subcutaneous LLC-GFP tumor models and toll-like receptor 2 (TLR2) knockout mice; in vitro assessments were conducted using TLR2 knockout and both LLC-GFP and LN227 lentiviral-mediated knockdown (KD) cells. Results: Cancer cells released a secreted form of Hsp70 that acted on MΦ TLR2 to upregulate Mer receptor tyrosine kinase (MerTK) and induce MΦ M2 polarization. Hsp70 nAbs led to a reduction in CD14 expression by 75% in THP-1 cells in response to Gli36 EMD-CM. In addition, neutralizing TLR2 nAbs resulted in a 30% and 50% reduction in CD14 expression on THP-1 cells in response to MiaPaCa-2 and Gli36 exosome/microparticle-depleted conditioned media (EMD-CMs), respectively. Hsp70, TLR2, and MerTK formed a protein complex. Tumor growth and intra-tumor M2 MΦs were significantly reduced upon cancer cell Hsp70 knockdown and in TLR2 knockout mice. Conclusions: Cancer-secreted Hsp70 interacts with TLR2, upregulates MerTK on MΦs, and induces immunosuppressive MΦ M2 polarization. This previously unreported action of secreted Hsp70 suggests that disrupting the Hsp70-TLR2-MerTK interaction could serve as a promising immunotherapeutic approach to mitigate TME immunosuppression in solid cancers. Full article

Rahnella aquatilis is an emerging pathogen in fish that poses a potential risk to human and public health. However, its pathogenicity and molecular interaction mechanism with the fish host are still poorly understood. For this study, we conducted analyses into the artificial infection, bacterial load, histopathological observation, and molecular characterization of T6SS, as well as its mediated host immune response to R. aquatilis infection. The results showed that the R. aquatilis KCL-5 strain had high pathogenicity in teleosts, such as the cyprinid fish crucian carp Carassius auratus and the zebrafish Danio rerio, as well as a macrophage infection model that was successfully established, both in vivo and in vitro. A significant time-dependent increase in bacterial distribution in the infected tissues of crucian carp was examined using real-time qPCR and immunohistochemical analysis. The recombinant plasmid pET32a-hcp of T6SS was constructed and the fusion protein was of the expected size of 35.9 kD, as shown by SDS-PAGE and Western blot analysis. Moreover, the single-cell identification of kidney-derived Mφ/Mo cells was achieved, defined with the potential cellular marker gene expression in each cell and the genes’ expression of bacterial chemotaxis and flagellar assembly, inflammation, and PRRs, as well as the T6SS-mediated interaction between fish host cells and KCL-5, which was verified by multi-omics analysis. To our knowledge, this is the first report of T6SS/PAMPs-PRRs pathways related to the emerging R. aquatilis pathogen–host interaction mechanism in fish. Full article

Traumatic optic neuropathy (TON) has been regarded a vision-threatening condition caused by either ocular or blunt/penetrating head trauma, which is characterized by direct or indirect TON. Injury happens during sports, vehicle accidents and mainly in military war and combat exposure. Earlier, we have demonstrated that remote ischemic post-conditioning (RIC) therapy is protective in TON, and here we report that AMPKα1 activation is crucial. AMPKα1 is the catalytic subunit of the heterotrimeric enzyme AMPK, the master regulator of cellular energetics and metabolism. The α1 isoform predominates in immune cells including macrophages (Mφs). Myeloid-specific AMPKα1 KO mice were generated by crossing AMPKα1^Flox/Flox and LysM^cre to carry out the study. We induced TON in mice by using a controlled impact system. Mice (mixed sex) were randomized in six experimental groups for Sham (mock); Sham (RIC); AMPKα1^F/F (TON); AMPKα1^F/F (TON+RIC); AMPKα1^F/F LysM^Cre (TON); AMPKα1^F/F LysM^Cre (TON+RIC). RIC therapy was given every day (5–7 days following TON). Data were generated by using Western blotting (pAMPKα1, ICAM1, Brn3 and GAP43), immunofluorescence (pAMPKα1, cd11b, TMEM119 and ICAM1), flow cytometry (CD11b, F4/80, CD68, CD206, IL-10 and LY6G), ELISA (TNF-α and IL-10) and transmission electron microscopy (TEM, for demyelination and axonal degeneration), and retinal oxygenation was measured by a Unisense sensor system. First, we observed retinal morphology with funduscopic images and found TON has vascular inflammation. H&E staining data suggested that TON increased retinal inflammation and RIC attenuates retinal ganglion cell death. Immunofluorescence and Western blot data showed increased microglial activation and decreased retinal ganglion cell (RGCs) marker Brn3 and axonal regeneration marker GAP43 expression in the TON [AMPKα1^F/F] vs. Sham group, but TON+RIC [AMPKα1^F/F] attenuated the expression level of these markers. Interestingly, higher microglia activation was observed in the myeloid AMPKα1^F/F KO group following TON, and RIC therapy did not attenuate microglial expression. Flow cytometry, ELISA and retinal tissue oxygen data revealed that RIC therapy significantly reduced the pro-inflammatory signaling markers, increased anti-inflammatory macrophage polarization and improved oxygen level in the TON+RIC [AMPKα1^F/F] group; however, RIC therapy did not reduce inflammatory signaling activation in the myeloid AMPKα1 KO mice. The transmission electron microscopy (TEM) data of the optic nerve showed increased demyelination and axonal degeneration in the TON [AMPKα1^F/F] group, and RIC improved the myelination process in TON [AMPKα1^F/F], but RIC had no significant effect in the AMPKα1 KO mice. The myeloid AMPKα1c deletion attenuated RIC induced anti-inflammatory macrophage polarization, and that suggests a molecular link between RIC and immune activation. Overall, these data suggest that RIC therapy provided protection against inflammation and neurodegeneration via myeloid AMPKα1 activation, but the deletion of myeloid AMPKα1 is not protective in TON. Further investigation of RIC and AMPKα1 signaling is warranted in TON. Full article

Background: Calcific aortic valve disease (CAVD) is a highly prevalent disease, especially in the elderly population, but there are no effective drug therapies other than aortic valve repair or replacement. CAVD develops preferentially on the fibrosa side, while the ventricularis side remains relatively spared through unknown mechanisms. We hypothesized that the fibrosa is prone to the disease due to side-dependent differences in transcriptomic patterns and cell phenotypes. Methods: To test this hypothesis, we performed single-cell RNA sequencing using a new method to collect endothelial-enriched samples independently from the fibrosa and ventricularis sides of freshly obtained human aortic valve leaflets from five donors, ranging from non-diseased to fibrocalcific stages. Results: From the 82,356 aortic valve cells analyzed, we found 27 cell clusters, including seven valvular endothelial cell (VEC), nine valvular interstitial cell (VIC), and seven immune, three transitional, and one stromal cell population. We identified several side-dependent VEC subtypes with unique gene expression patterns. Homeostatic VIC clusters were abundant in non-diseased tissues, while VICs enriched with fibrocalcific genes and pathways were more prevalent in diseased leaflets. Furthermore, homeostatic macrophage (MΦ) clusters decreased while inflammatory MΦ and T-cell clusters increased with disease progression. A foamy MΦ cluster was increased in the fibrosa of mildly diseased tissues. Some side-dependent VEC clusters represented non-diseased, protective phenotypes, while others were CAVD-associated and were characterized by genes enriched in pathways of inflammation, endothelial–mesenchymal transition, apoptosis, proliferation, and fibrosis. Interestingly, we found several activator protein-1 (AP-1)-related transcription factors (FOSB, FOS, JUN, JUNB) and EGR1 to be upregulated in the fibrosa and diseased aortic valve leaflets. Conclusions: Our results showed that VECs are highly heterogeneous in a side- and CAVD-dependent manner. Unique VEC clusters and their differentially regulated genes and pathways found in the fibrosa of diseased tissues may represent novel pathogenic mechanisms and potential therapeutic targets. Full article

S100A8 is a protein that is abundant in neutrophils and macrophages (MΦ), but its role in inflammation remains unclear. This study aimed to assess the immunological role(s) of S100A8 in acute intestinal inflammation in rats and its role in MΦ. Rat recombinant S100A8 (rr-S100A8, 1.0 mg/kg) was intraperitoneally administered daily to rats with 3% dextran sulfate sodium (DSS) (DSS + A8 group)-induced experimental acute colitis. The histological severity score (6.50 ± 0.51, p = 0.038) in the DSS + A8 group rats remained lower than that (9.75 ± 1.48) of the rats without S100A8 (DSS group) administration. The tumor necrosis factor-alpha (TNF-α) production in the colon tissues of the rats in the DSS + A8 group (4.76 ± 0.90 pg/mL/g, p = 0.042) was significantly suppressed, compared with that of the DSS group (10.45 ± 2.04 pg/mL/g). To stimulate rat peritoneal MΦ, rr-S100A8, the anti-rat S100A8 antibody, and a lipopolysaccharide (LPS) were used in the in vitro experiments. In the MΦ stimulated with rr-S100A8 for 2 h, the mRNA level of intracellular S100A8 (47.41 ± 24.44, p = 0.002) increased in an autocrine manner, whereas that of S100A9 (0.24 ± 0.43, p = 0.782) was not significant. The TNF-α mRNA level in the MΦ treated with LPS and the anti-rat S100A8 antibody significantly increased (102.26 ± 18.60, p = 0.001) compared to that with LPS alone (16.9 ± 8.56). These results indicate that S100A8 can serve as an anti-inflammatory protein in acute inflammation by negatively regulating S100A9 and TNF-α production through inflammatory signaling pathways in MΦ. Full article

Numerous viruses that propagate through the respiratory tract may be initially engulfed by macrophages (Mφs) within the alveoli, where they complete their first replication cycle and subsequently infect the adjacent epithelial cells. This process can lead to significant pathological damage to tissues and organs, leading to various diseases. As essential components in host antiviral immune systems, Mφs can be polarized into pro-inflammatory M1 Mφs or anti-inflammatory M2 Mφs, a process involving multiple signaling pathways and molecular mechanisms that yield diverse phenotypic and functional features in response to various stimuli. In general, when infected by a virus, M1 macrophages secrete pro-inflammatory cytokines to play an antiviral role, while M2 macrophages play an anti-inflammatory role to promote the replication of the virus. However, recent studies have shown that some viruses may exhibit the opposite trend. Viruses have evolved various strategies to disrupt Mφ polarization for efficient replication and transmission. Notably, various factors, such as mechanical softness, the altered pH value of the endolysosomal system, and the homeostasis between M1/M2 Mφs populations, contribute to crucial events in the viral replication cycle. Here, we summarize the regulation of Mφ polarization, virus-induced alterations in Mφ polarization, and the antiviral mechanisms associated with these changes. Collectively, this review provides insights into recent advances regarding Mφ polarization in host antiviral immune responses, which will contribute to the development of precise prevention strategies as well as management approaches to disease incidence and transmission. Full article

Colon cancer ranks second in overall cancer-related deaths and poses a serious risk to human life and health. In recent years, exosomes are believed to play an important and significant role in cancer, especially tumor-derived exosomes (TDEs). Previous studies have highlighted the pivotal role of exosomes in tumor development, owing to their ability to mediate communication between tumor cells and macrophages, induce macrophage M2 polarization, and facilitate the progression of tumorigenesis. In this study, we revealed that colon cancer-derived exosomes promoted M2-like macrophage polarization. Moreover, exosome-induced M2-like macrophages, in turn, promoted the proliferation, migration, and invasion abilities of colon cancer cells. Specifically, CT26- and HCT116-derived exosomes led to the activation of AKT, ERK, and STAT3/6 signaling pathways in THP-1(Mφ) cells. Furthermore, our findings showed that colon cancer-derived exosomes secreted lncXIST to sponge miR-17-5p, which, in turn, promoted the expression of PDGFRA, a common gene found in all three signaling pathways, to facilitate M2-like macrophage polarization. Dual-luciferase reporter assays confirmed the binding relationship between lncXIST and miR-17-5p, as well as miR-17-5p and PDGFRA. Collectively, our results highlight the novel role of lncXIST in facilitating macrophage polarization by sponging miR-17-5p and regulating PDGFRA expression. Full article

Brain injuries, such as ischemic stroke, cause cell death. Although phagocytosis of cellular debris is mainly performed by microglia/macrophages (MGs/MΦs), excessive accumulation beyond their phagocytic capacities results in waste product buildup, delaying brain cell regeneration. Therefore, it is essential to increase the potential for waste product removal from damaged brains. Lipocalin-type prostaglandin D synthase (L-PGDS) is the primary synthase for prostaglandin D2 (PGD2) and has been reported as a scavenger of waste products. However, the mechanism by which the L-PGDS–PGD2 axis exerts such an effect remains unelucidated. In this study, using a mouse model of ischemic stroke, we found that L-PGDS and its downstream signaling pathway components, including PGD2 and PGD2 receptor DP1 (but not DP2), were significantly upregulated in ischemic areas. Immunohistochemistry revealed the predominant expression of L-PGDS in the leptomeninges of ischemic areas and high expression levels of DP1 in CD36⁺ MGs/MΦs that were specifically present within ischemic areas. Furthermore, PGD2 treatment promoted the conversion of MGs/MΦs into CD36⁺ scavenger types and increased phagocytic activities of CD36⁺ MGs/MΦs. Because CD36⁺ MGs/MΦs specifically appeared within ischemic areas after stroke, our findings suggest that the L-PGDS–PGD2–DP1 axis plays an important role in brain tissue repair by regulating phagocytic activities of CD36⁺ MGs/MΦs. Full article