Viruses constitute a significant group of pathogens that have caused numerous fatalities and substantial economic losses in recent years, particularly with the emergence of coronaviruses. While the impact of SARS-CoV-2 appears to be diminishing in daily life, only a limited number of drugs have received approval or emergency use authorization for its treatment. Given the high mutation rate of viral genomes, host-directed agents (HDAs) have emerged as a preferred choice due to their broad applicability and lasting effectiveness. In contrast to direct-acting antivirals (DAAs), HDAs offer several advantages, including broad-spectrum antiviral activities, potential efficacy against future emerging viruses, and a lower likelihood of inducing drug resistance. In our review article, we have synthesized known host-directed antiviral targets that span diverse cellular pathways and mechanisms, shedding light on the intricate interplay between host cells and viruses. Additionally, we have provided a brief overview of the development of HDAs based on these targets. We aim for this comprehensive analysis to offer valuable perspectives and insights that can guide future antiviral research and drug development efforts.

Human respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections in infants and young children, as well as an important cause of respiratory tract infections in immunocompromised patients and the elderly, which poses a significant economic and social burden worldwide. In recent years, substantial progress has been made in understanding the structure and function of RSV proteins and the interactions between RSV with host factors which is helpful to the discovery of new therapeutic targets and the development of novel interventions. Although two vaccines and two monoclonal antibodies for RSV prevention have been approved, the antiviral treatment remains an unmet clinical need. In this review, we summarize the structure, protein functional properties, and pathological mechanisms of RSV and the current status of RSV drug development. In addition, remaining challenges and innovative ideas for RSV prevention and treatment have also been highlighted.

As the most abundant and essential structural protein in the human body, collagen is ubiquitously present in the interstitium of nearly all solid organs, playing a crucial role in maintaining the structural integrity and functional stability of human tissues and organs. Disorders associated with collagen structure and metabolisms impose a significant burden on society and healthcare systems. Post-translational modifications (PTMs) are essential steps in collagen metabolism, and recent studies have indicated that aberrant regulation of PTMs plays a pivotal role in the pathogenesis and progress of collagen-related disorders, including liver, kidney, heart, lung, and skin fibrosis, as well as keloid. This review provides a comprehensive summary of the regulatory mechanisms of both traditional and novel PTMs in collagen metabolism and collagen-related diseases. Furthermore, we summarize the drugs that modulate PTMs and their effects, with the aim of elucidating the pathophysiology of collagen-related diseases and provide new insights for their diagnosis, prevention, and treatment.

Adjuvants as essential ingredients amplify the magnitude and durability of immune responses in various vaccine strategies. Polysaccharides with potent immunoenhancing effects are widely applied as promising vaccine adjuvants, however, they have rarely been licensed for use in human vaccines due to the limitation of their efficacy and safety. Moreover, nanoparticles not only act as antigen drug delivery vectors but also possess intrinsic adjuvant functions, revealing the dual effects of nanoparticles in augmenting antigen-specific immune responses. Intriguingly, nanoparticle forms can enhance the immunostimulatory potency of polysaccharide adjuvants, since polysaccharide nanoparticles exert more excellent adjuvant effects than polysaccharides in initiating humoral, cellular and mucosal immune responses. Emerging evidence has also suggested that multiple immune-related signaling pathways including cGAS–STING, NLRP3, TLRs, cell death or metabolism signaling probably participate in the immunomodulation of polysaccharide nanoparticles, but systemic investigations into the adjuvant mechanism are still inadequate. This review aims to give an updated summary and discussion on the adjuvant function and mechanism of polysaccharide nanoparticles for understanding their superior adjuvant property and effectively utilizing them as potent immune adjuvants in vaccine development.

As the intricate interplay between microbiota and the host garners increasing research attention, a significant parallel surge has emerged in the investigation of intestinal bacterial extracellular vesicles (BEVs). Most intestinal bacteria secrete BEVs, which harbor specific cargo molecules and exhibit diverse functions, encompassing interactions among bacteria themselves and between bacteria and the host. These interactions can either bolster host health or contribute to various pathologies. By integrating the characteristics of BEVs, we summarized the current research landscape, delving into the intricate interplay between BEVs and different diseases. Furthermore, we offer a succinct overview of the challenges faced in BEVs-based research, encompassing separation, detection, engineering for drug purposes, clinical diagnostics, safety, and future study. In essence, these summaries may serve as invaluable guides for BEVs as communication tools between the gut microbiome and host, ultimately propelling the discovery of novel studies and drug discovery.

Tumor metastasis is the leading cause of high mortality in most cancers, and numerous studies have demonstrated that the malignant crosstalk of multiple components in the tumor microenvironment (TME) together promotes tumor metastasis. Cancer-associated fibroblasts (CAFs) are the major stromal cells and crosstalk centers in the TME of various kinds of tumors, such as breast cancer, pancreatic cancer, and prostate cancer. Recently, the CAF-induced pro-tumor metastatic TME has gained wide attention, being considered as one of the effective targets for tumor therapy. With in-depth research, CAFs have been found to promote tumor metastasis through multiple mechanisms, such as inducing epithelial–mesenchymal transition in tumor cells, remodeling the extracellular matrix, protecting circulating tumor cells, and facilitating the formation of a pre-metastatic niche. To enhance the anti-tumor metastasis effect, therapeutic strategies designed by combining nano-drug delivery systems with CAF modulation are undoubtedly a desirable choice, as evidenced by the research over the past decades. Herein, we introduce the physiological properties of CAFs, detail the possible mechanisms whereby CAFs promote tumor metastasis, categorize CAFs-based nano-drug delivery strategies according to their anti-metastasis functions and discuss the current challenges, possible solutions, as well as the future directions in order to provide a theoretical basis and reference for the utilization of CAFs-based nano-drug delivery strategies to promote tumor metastasis therapy.

Cancer immunotherapy has emerged as a promising strategy. However, low response rates and immune-related side effects have plagued immunotherapy. Metallic nanoparticles, utilizing metals as their framework, are gaining prominence in cancer immunotherapy. Metal ions have shown the ability to modulate immune status by activating the cGAS–STING pathway and inducing immunogenic cell death (ICD), thereby enabling multidimensional activation of immunotherapy. Metallic nanoparticles offer significant advantages in cancer immunotherapy, leading to their increasing use in enhancing therapeutic outcomes. In view of the ever-increasing research on metallic nanoparticles, this review presents the construction, characterization, and enhanced cancer immunotherapeutic effects of different types of metal nanosystems from the perspective of the immunoregulatory mechanisms of metal ions. We delve into the current limitations and future directions of metallic nanoparticles in this rapidly evolving field. To the best of our knowledge, this review offers the most up-to-date and systematic analysis of metallic nanoparticles in immunotherapeutic applications. It is anticipated that this review of metallic nanoparticles will inspire a more refined and intelligent design of metallic nanoparticles for future research, paving the way for advancing their clinical applications.