Chimeric Antigen Receptor (CAR) technology has revolutionized cellular immunotherapy, particularly with the success of CAR-T cells in treating hematologic malignancies. However, CAR-T cells have the limited efficacy of against solid tumors. To address these limitations, CAR-macrophages (CAR-Ms) leverage the innate properties of macrophages with the specificity and potency of CAR technology, offering a novel and promising approach to cancer immunotherapy. Preclinical studies have shown that CAR-Ms can effectively target and destroy tumor cells, even within challenging microenvironments, by exhibiting direct cytotoxicity and enhancing the recruitment and activation of other immune cells. Additionally, the favorable safety profile of macrophages and their persistence within solid tumors position CAR-Ms as potentially safer and more durable therapeutic options compared to CAR-T cells. This review explores recent advancements in CAR-Ms technology, including engineering strategies to optimize their anti-tumor efficacy and preclinical evidence supporting their use. We also discuss the challenges and future directions in developing CAR-Ms therapies, emphasizing their potential to revolutionize cellular immunotherapy. By harnessing the unique properties of macrophages, CAR-Ms offer a groundbreaking approach to overcoming the current limitations of CAR-T cell therapies, paving the way for more effective and sustainable cancer treatments.

There has been a growing interest in studying the communication of gut microbial metabolites between the gut and the liver as liver fibrosis progresses. Although 3-Indolepropionic acid (IPA) is regarded as a clinically valuable gut metabolite for the treatment of certain chronic diseases, the effects of oral administration of IPA on hepatic fibrosis in different animal models have been conflicting. While some mechanisms have been proposed to explain these contradictory effects, the direct impact of IPA on hepatic fibrosis remains unclear. In this study, we found that IPA could directly activate LX-2 human hepatic stellate cells in vitro. IPA upregulated the expression of fibrogenic marker genes and promoted the features associated with HSCs activation, including proliferation and contractility. IPA also increased reactive oxygen species (ROS) in mitochondria and the expression of inflammation-related genes in LX-2 cells. However, when a ROS-blocking agent was used, these effects were reduced. p38 and JNK, the downstream signaling cascades of ROS, were found to be required for the activation of LX-2 induced by IPA. These findings suggest that IPA can directly activate hepatic stellate cells through ROS-induced JNK and p38 signaling pathways.

The activation of hepatic stellate cells (HSCs), characterized by transdifferentiation from a quiescent state to a fibrogenic phenotype, is a core process of liver fibrosis. The metabolic reprogramming of HSCs plays a major role in this process to meet the high energy demands of myofibroblastic HSCs with multiple functions, such as extracellular matrix synthesis, migration, and proliferation. AMP-activated protein kinase (AMPK) is a gatekeeper of intracellular energy homeostasis, but its role in the activation of HSCs and the progression of liver fibrosis remains unclear. Here, we found that the phosphorylation of AMPK in HSCs was upregulated in liver tissues from metabolic dysfunction-associated steatohepatitis patients and from mice treated with carbon tetrachloride (CCl4) or bile duct ligation (BDL). HSC-specific deletion of two catalytic α-subunits of AMPK attenuated liver fibrosis in the CCl4 or BDL mouse model. In vitro analysis demonstrated that AMPK promoted HSC activation upon various profibrogenic stimuli. The activation of AMPKα-deficient HSCs was impaired due to the decreased mitochondrial oxidative phosphorylation but restored after treatment with the mitophagy inducer rapamycin. Mechanistically, both the AMPK–ULK1 and AMPK–Raptor pathways contribute to the maintenance of the mitophagy pathway and mitochondrial quality. These findings provide direct evidence of the crucial role of AMPK–mitophagy signaling in ensuring mitochondrial health and sufficient energy supply during HSC activation. In this study, AMPK was modulated in HSCs prior to activation, which is distinguished from previous investigations and thus provides new insights into the role of AMPK during distinct phases of HSC activation.

Chimeric antigen receptor-T (CAR-T) cell therapy has made remarkable strides in treating hematological malignancies. However, the widespread adoption of CAR-T cell therapy is hindered by several challenges. These include concerns about the long-term and complex manufacturing process, as well as efficacy factors such as tumor antigen escape, CAR-T cell exhaustion, and the immunosuppressive tumor microenvironment. Additionally, safety issues like the risk of secondary cancers post-treatment, on-target off-tumor toxicity, and immune effector responses triggered by CAR-T cells are significant considerations. To address these obstacles, researchers have explored various strategies, including allogeneic universal CAR-T cell development, infusion of non-activated quiescent T cells within a 24-hour period, and in vivo induction of CAR-T cells. This review comprehensively examines the clinical challenges of CAR-T cell therapy and outlines strategies to overcome them, aiming to chart pathways beyond its current Achilles heels.

Combination therapy, involving the concurrent use of multiple medications, has become crucial for managing complex diseases with diverse pathological mechanisms. Fixed-Dose Combinations (FDCs) are formulated to leverage the synergistic effects of multiple drugs, thereby enhancing therapeutic outcomes. However, conventional FDCs typically maintain therapeutic effects for only up to 24 h and require frequent dosing, which often results in patient non-compliance and inconsistent treatment responses, especially in chronic diseases. This highlights the urgent need for long-acting FDCs that can provide sustained drug release over extended periods-weeks, months, or even years-thereby reducing dosing frequency and enhancing patient adherence. Microspheres, with their ability to encapsulate and release multiple medications in predefined patterns, are highly advantageous for developing long-acting FDC drugs. This review emphasizes the increasing demand for long-acting FDC drugs that ensure sustained drug release, reduce dosing frequency, and ultimately improve patient adherence. We also highlight the potential of microsphere technology, which enables precise encapsulation and sustained release of multiple medications, as a promising approach for revolutionizing long-acting FDCs with enhanced therapeutic outcomes.