Gum Arabic in combination with IFN-γ promotes the M1 polarization in macrophage

Apoptotic and anti-inflammatory effect of nisin-loaded sodium alginate-gum arabic nanoparticles against colon cancer cells

Colon cancer is one of the leading causes of mortality and morbidity worldwide. Nisin, a polycyclic antibacterial peptide and food preservative has shown potential to combat cancer. However, it is susceptible to proteolytic cleavage in the gut. The current study investigates the protective and cytotoxic effects of nisin loaded sodium alginate gum arabic nanoparticles (Nis/ALG-GA NPs) in Caco2 cells. The physicochemical properties, loading efficiency and release kinetics were studied. Cytotoxicity (MTT assay), apoptotic effect (Ethidium bromide and acridine orange staining) and internalisation (FITC tagging) were evaluated. Gene expression of apoptotic markers and IL-10 were analysed by qPCR. The Nis/ALG-GA NPs were spherical, small with a smooth outer surface and mean size of 193 ± 4 nm. The loading efficacy was 88 ± 2 % exhibiting slow sustained release of the peptide under different gut pH conditions. The IC50 value obtained was 500 μg for 48 h and 80 μg for 72 h of incubation. The Nis/ALG-GA NPs were internalised into Caco2 cells and induced apoptosis with an increased expression of bax gene and converse decrease of bcl-2 gene. Anti-inflammatory gene IL10 was upregulated upon treatment with NPs. Thus, the Nis/ALG-GA NPs may be promising oral drug delivery systems against colon cancers.

Co-delivery of Interferon Regulatory Factor 5 (IRF5) siRNA and dasatinib by a disulfide bond bearing polymeric carrier for enhanced anti-inflammatory effects

Co-delivery of chemical drugs and nucleic acids has attracted a great interest recently for treatment of inflammatory diseases. Dasatinib (DB), a tyrosine kinase inhibitor with anti-cancer effects, and Interferon Regulatory Factor 5 (IRF5) siRNA have shown anti-inflammatory effects. In the present study, a novel redox-responsive polymeric micelle was designed for co-delivery of DB and IRF5 siRNA-expressing plasmid (psiRF5) to enhance anti-inflammatory effects on macrophages. psiRF5 was condensed efficiently to redox-responsive micelles of DB-conjugated chitosan (CN) composed of disulfide bond, from different molecular weights of CN to form CN-SS-DB/psiRF5 micelles. The micelles with optimum N/P ratios had particle sizes of 287.8 and 245.4 nm and positive zeta potentials. The disulfide bond bearing micelles showed a redox-responsive drug release, protected the plasmid from being dissociated or degraded in exposure with heparin, serum and DNase I, and significantly enhanced the transfection efficiency and IRF5-gene silencing compared to naked psiRF5. The optimum micelles exhibited a dramatic reduction in IRF5 expression and revealed a notably higher anti-inflammatory effect than either DB or psiRF5, as indicated by more IL-10 and less IL-6 and TNF-α production by LPS-stimulated RAW264.7 macrophages incubated with the co-delivery system. The resultant nanocarriers might be promising for more effective treatment of inflammatory diseases.

Structural characterization and immune modulation activities of Chinese Angelica polysaccharide (CAP) and selenizing CAP (sCAP) on dendritic cells

sCAP was obtained by the nitrate‑sodium selenite method. SEM, molecular weight evaluation, monosaccharide composition, FT-IR and NMR of sCAP were carried out. Compared with CAP, sCAP had a relatively smooth and lamellar sheet morphology with edge folds on the surface, presented molecular weights in range of 0.90-97.08 KDa, and was mainly composed of GalA, Ara and Gal. sCAP had both α and β configurations of the pyranose ring, the characteristic vibrational peak of Se-O-C and the signal of galacturonic acid residue. The phagocytic activity of immature BMDCs, the expression of CD40, CD80, CD86, and MHCII on BMDCs were detected by flow cytometry, the ability of sCAP-treated BMDCs to stimulate the proliferation of allogeneic lymphocytes, presentation of antigens, cytokines in the supernatants and the protein in MyD88/NF-κB signaling pathway were detected. The results showed that the phagocytic activity of immature BMDCs was significantly enhanced when sCAP was at 3.92-1.96 μg·mL-1. The levels of IL-6, TGF-β1, INF-γ, and TNF-α were significantly elevated, IL-1β and MIP-1α were significantly reduced. These results indicate that sCAP could be as a new immunopotentiator by increasing MyD88/NF-κB signaling pathway. This study provides a reference for the research and development of new dosage forms of polysaccharide.

Engineering macrophages and their derivatives: A new hope for antitumor therapy

Macrophages are central to the immune system and are found in nearly all tissues. Recently, the development of therapies based on macrophages has attracted significant interest. These therapies utilize macrophages' key roles in immunity, their ability to navigate biological barriers, and their tendency to accumulate in tumors. This review explores the advancement of macrophage-based treatments. We discuss the bioengineering of macrophages for improved anti-tumor effects, the use of CAR macrophage therapy for targeting cancer cells, and macrophages as vehicles for therapeutic delivery. Additionally, we examine engineered macrophage products, like extracellular vesicles and membrane-coated nanoparticles, for their potential in precise and less toxic tumor therapy. Challenges in moving these therapies from research to clinical practice are also highlighted. The aim is to succinctly summarize the current status, challenges, and future directions of engineered macrophages in cancer therapy.

Gum acacia dietary fiber: Significance in immunomodulation, inflammatory diseases, and cancer

Gum arabic/acacia (GA), derived from Acacia trees, is a versatile natural product offering a broad spectrum of applications. Its rich content of soluble dietary fibers, coupled with a low caloric profile, renders GA a valuable dietary component associated with numerous health benefits. Furthermore, its fermentation by gut microbiota yields short-chain fatty acids, renowned for their positive impact on health. Immunomodulation, a crucially regulated mechanism in the body, serves to fend off pathogenic infections by releasing pro-inflammatory cytokines. However, prolonged synthesis of these cytokines can lead to chronic inflammation, tissue damage, and potentially contribute to the development of autoimmune diseases and cancer. Hence, there is an urgent need to identify plant-based biomolecules that can effectively reduce inflammation and inhibit inflammation-induced complications or disorders. In this context, edible biomolecules like GA are gaining prominence for their noteworthy immunomodulatory properties. Therefore, in the present review we have explored the role of GA in immunomodulation, inflammation, and inflammation-associated metabolic diseases, and cancer.

Targeting reactive oxygen species and fat acid oxidation for the modulation of tumor-associated macrophages: a narrative review

Tumor-associated macrophages (TAMs) are significant immunocytes infiltrating the tumor microenvironment(TME). Recent research has shown that TAMs exhibit diversity in terms of their phenotype, function, time, and spatial distribution, which allows for further classification of TAM subtypes. The metabolic efficiency of fatty acid oxidation (FAO) varies among TAM subtypes. FAO is closely linked to the production of reactive oxygen species (ROS), which play a role in processes such as oxidative stress. Current evidence demonstrates that FAO and ROS can influence TAMs' recruitment, polarization, and phagocytosis ability either individually or in combination, thereby impacting tumor progression. But the specific mechanisms associated with these relationships still require further investigation. We will review the current status of research on the relationship between TAMs and tumor development from three aspects: ROS and TAMs, FAO and TAMs, and the interconnectedness of FAO, ROS, and TAMs.

Active ingredients of traditional Chinese medicine for enhancing the effect of tumor immunotherapy

Immunotherapy is a type of treatment that uses our own immune system to fight cancer. Studies have shown that traditional Chinese medicine (TCM) has antitumor activity and can enhance host immunity. This article briefly describes the immunomodulatory and escape mechanisms in tumors, as well as highlights and summarizes the antitumor immunomodulatory activities of some representative active ingredients of TCM. Finally, this article puts forward some opinions on the future research and clinical application of TCM, aiming to promote the clinical applications of TCM in tumor immunotherapy and to provide new ideas for the research of tumor immunotherapy using TCM.