Breast cancer continues to be the most frequently diagnosed malignancy among women, putting their life in jeopardy. Cancer immunotherapy is a novel approach with the ability to boost the host immune ...system to recognize and eradicate cancer cells with high selectivity. As a promising treatment, immunotherapy can not only eliminate the primary tumors, but also be proven to be effective in impeding metastasis and recurrence. However, the clinical application of cancer immunotherapy has faced some limitations including generating weak immune responses due to inadequate delivery of immunostimulants to the immune cells as well as uncontrolled modulation of immune system, which can give rise to autoimmunity and nonspecific inflammation. Growing evidence has suggested that nanotechnology may meet the needs of current cancer immunotherapy. Advanced biomaterials such as nanoparticles afford a unique opportunity to maximize the efficiency of immunotherapy and significantly diminish their toxic side-effects. Here we discuss recent advancements that have been made in nanoparticle-involving breast cancer immunotherapy, varying from direct activation of immune systems through the delivery of tumor antigens and adjuvants to immune cells to altering immunosuppression of tumor environment and combination with other conventional therapies.
There is growing evidence showing that single administration of immunotherapeutic agents has limited efficacy in a number of cancer patients mainly due to tumor heterogeneity and immunosuppressive ...tumor microenvironment. In this study, a novel nanoparticle-based strategy was applied to achieve efficient tumor-targeted therapy by combining chemotherapeutic agents, i.e., doxorubicin (Dox) and melittin (Mel), with an immune checkpoint inhibitor (PD-L1 DsiRNA). The proposed nanoparticle was prepared by the formation of a complex between Mel and PD-L1 DsiRNA (Dicer-substrate short-interfering RNA), followed by the loading of Dox. The surface of the resultant particles (DoxMel/PD-L1 DsiRNA) was then modified with hyaluronic acid (HA) to increase their stability and distribution. In addition, HA can also act as a tumor-targeting agent through binding to its receptor CD44 on the surface of cancer cells. We demonstrated that the surface engineering of DoxMel/PD-L1 DsiRNA with HA significantly enhances its specificity towards breast cancer cells. Moreover, we observed a noticeable reduction in PD-L1 expression together with a synergistic effect of Dox and Mel on killing cancer cells and inducing immunogenic cell death, leading to significantly diminished tumor growth in 4T1-breast tumor bearing Balb/c mice, improved survival rate and extensive infiltration of immune cells including cytotoxic T cells into the tumor microenvironment. Safety analysis revealed that there is no significant toxicity associated with the developed nanoparticle. All in all, the proposed targeted combination treatment strategy can be considered as a useful method to reduce cancer-associated mortality.
•A novel nanoparticle-based chemo-immunotherapy (DoxMel/PD-L1 DsiRNA@HA) for breast cancer was developed.•DoxMel/PD-L1 DsiRNA@HA significantly suppressed both primary and distant breast tumors in tumor-bearing Balb/c mice.•Induction of ICD along with suppression of PD-L1 expression by DoxMel/PD-L1 DsiRNA@HA led to a robust systemic immunity against cancer cells.•DoxMel/PD-L1 DsiRNA@HA has high potential for future clinical translation due to its high safety profile and strong anti-tumor efficacy.
Melanoma is a malignant tumor that accounts for the deadliest form of skin cancers. Despite the significant efforts made recently for development of immunotherapeutic strategies including using ...immune checkpoint inhibitors and cancer vaccines, the clinical outcomes are unsatisfying. Different factors affect efficient cancer immunotherapy such as side-effects, immunosuppressive tumor microenvironment, and tumor heterogeneity. In the past decades, various nanotechnology-based approaches have been developed to enhance the efficacy of cancer immunotherapy, in addition to diminishing the toxicity associated with it. Several studies have shown that proper application of nanomaterials can revolutionize the outcome of immunotherapy in diverse melanoma models. This review summarizes the recent advancement in the integration of nanotechnology and cancer immunotherapy in melanoma treatment. The importance of nanomaterials and their therapeutic advantages for patients with melanoma are also discussed.
Simultaneous delivery of tumor antigens and adjuvants to antigen presenting cells via nanoparticles activates T cells to attack cancer cells. This causes cancer cell death and release of tumor antigens into the tumor microenvironment, further stimulating the immune system. Display omitted
•Nanoparticles can diminish toxicity associated with free immunotherapeutic drug administration.•Delivery of nanoparticle-based vaccine can elicit a strong immune response against cancer cells.•Nanoparticle-based combination therapies can produce more effective therapeutic results.
Enteroviruses (EVs) are the most common human pathogens worldwide. Recent international outbreaks in North America and South East Asia have emphasized the need for more effective anti-viral ...therapies. As obligate parasites, EVs rely on the host cellular machinery for effective viral propagation. Accumulating evidence has indicated that EVs subvert and disrupt the cellular autophagy pathway to facilitate productive infection, and consequently leading to host pathogenesis. Given that defective autophagy is a common factor in various human diseases, including neurodegeneration, cardiomyopathy, and metabolic disorders, a clear understanding of the relationship between EV infection and autophagy is warranted. In this review, we highlight recent advances in understanding the molecular mechanisms by which EVs exploit the autophagy pathway during different steps of viral life cycle, from entry, replication, and maturation to release. We also provide an overview of recent progress in EV subversion of the autophagy for immune evasion.
Picornaviruses have evolved to hijack host cellular machinery, including the autophagic pathway. However, the mechanisms remain largely unclear. We use coxsackievirus B3 (CVB3) as a model organism to ...explore the possible role of picornavirus subversion of the autophagic pathway in viral infection. Our in vivo and in vitro experiments demonstrate that CVB3 infection causes a significant, albeit incomplete, inhibition of autophagic flux by limiting the fusion of autophagosomes with lysosomes and/or late endosomes. Furthermore, we show that CVB3 specifically targets SNARE protein SNAP29 and adaptor protein PLEKHM1, two critical proteins known to regulate autophagosome fusion, for cleavage through the catalytic activity of viral proteinase 3C, ultimately impairing the formation of SNARE complexes. Finally, we demonstrate that loss of SNAP29/PLEKHM1 inhibits autophagic flux, resulting in increased viral replication. Collectively, our study reveals a mechanism that supports an emerging model whereby CVB3 hijacks the autophagic machinery to facilitate its own propagation.
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•CVB3 infection inhibits autophagosome-lysosome/late endosome fusion•CVB3 limits autophagic flux via cleavage of SNAP29 and PLEKHM1 by proteinase 3C•Knockdown of SNAP29 and/or PLEKHM1 facilitates viral replication
Mohamud et al. report that coxsackievirus limits autophagosome fusion with lysosomes and/or late endosomes through viral proteinase 3C-mediated cleavage of SNAP29 and PLEKHM1. This leads to the accumulation of autophagosomes that favor viral replication by providing additional membrane scaffolds.
The ongoing pandemic of COVID-19 alongside the outbreaks of SARS in 2003 and MERS in 2012 underscore the significance to understand betacoronaviruses as a global health challenge. SARS-CoV-2, the ...etiological agent for COVID-19, has infected over 50 million individuals’ worldwide with more than ∼1 million fatalities. Autophagy modulators have emerged as potential therapeutic candidates against SARS-CoV-2 but recent clinical setbacks urge for better understanding of viral subversion of autophagy. Using MHV-A59 as a model betacoronavirus, time-course infections revealed significant loss in the protein level of ULK1, a canonical autophagy-regulating kinase, and the concomitant appearance of a possible cleavage fragment. To investigate whether virus-encoded proteases target ULK1, we conducted in-vitro and cellular cleavage assays and identified ULK1 as a novel bona fide substrate of SARS-CoV-2 papain-like protease (PLpro). Mutagenesis studies discovered that ULK1 is cleaved at a conserved PLpro recognition sequence (LGGG) after G499, separating its N-terminal kinase domain from a C-terminal substrate recognition region. Over-expression of SARS-CoV-2 PLpro is sufficient to impair starvation-induced autophagy and disrupt formation of ULK1-ATG13 complex. Finally, we demonstrated a dual role for ULK1 in MHV-A59 replication, serving a pro-viral functions during early replication that is inactivated at late stages of infection. In conclusion, our study identified a new mechanism by which PLpro of betacoronaviruses induces viral pathogenesis by targeting cellular autophagy.
•ULK1 is a novel target of betacoronavirus.•SARS-COV-2 papain-like protease (PLpro) cleaves ULK1 after G499.•PLpro disrupts ULK1 complex and cellular autophagy.•ULK1 is required early but dispensable during late MHV-A59 infection.
The myocardium/heart is the most mitochondria-rich tissue in the human body with mitochondria comprising approximately 30% of total cardiomyocyte volume. As the resident "powerhouse" of cells, ...mitochondria help to fuel the high energy demands of a continuously beating myocardium. It is no surprise that mitochondrial dysfunction underscores the pathogenesis of many cardiovascular ailments, including those of viral origin such as virus-induced myocarditis. Enteroviruses have been especially linked to injuries of the myocardium and its sequelae dilated cardiomyopathy for which no effective therapies currently exist. Intriguingly, recent mechanistic insights have demonstrated viral infections to directly damage mitochondria, impair the mitochondrial quality control processes of the cell, such as disrupting mitochondrial antiviral innate immune signaling, and promoting mitochondrial-dependent pathological inflammation of the infected myocardium. In this review, we briefly highlight recent insights on the virus-mitochondria crosstalk and discuss the therapeutic implications of targeting mitochondria to preserve heart function and ultimately combat viral myocarditis.
Immunotherapy has emerged as an efficient therapeutic approach for cancer management. However, stimulation of host immune system against cancer cells often fails to achieve promising clinical ...outcomes mainly owing to the immunosuppressive characteristics of the tumor microenvironment (TME). Combination therapeutics that can trigger sustained immunogenic cell death (ICD) have provided new opportunities for cancer treatment.
In this study, we designed and applied an ICD inducer regimen, including a genetically engineered oncolytic virus (miRNA-modified coxsackieviruses B3, miR-CVB3), a pore-forming lytic peptide (melittin, found in bee venom), and a synthetic toll-like receptor 9 ligand (CpG oligodeoxynucleotides), for breast cancer and melanoma treatment. We compared the anti-tumor efficacy of miR-CVB3 and CpG-melittin (CpGMel) alone and in combination (miR-CVB3 + CpGMel) and investigated possible mechanisms involved.
We demonstrated that miR-CVB3 + CpGMel had no major impact on viral growth, while enhancing the cellular uptake of CpGMel in vitro. We further showed that combination therapy led to significant increases in tumor cell death and release of damage-associated molecular patterns compared with individual treatment. In vivo studies in 4T1 tumor-bearing Balb/c mice revealed that both primary and distant tumors were significantly suppressed, and the survival rate was significantly prolonged after administration of miR-CVB3 + CpGMel compared with single treatment. This anti-tumor effect was accompanied by increased ICD and immune cell infiltration into the TME. Safety analysis showed no significant pathological abnormalities in Balb/c mice. Furthermore, the developed therapeutic regimen also demonstrated a great anti-tumor activity in B16F10 melanoma tumor-bearing C57BL/6 J mice.
Overall, our findings indicate that although single treatment using miR-CVB3 or CpGMel can efficiently delay tumor growth, combining oncolytic virus-based therapy can generate even stronger anti-tumor immunity, leading to a greater reduction in tumor size.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Genetic analyses of patients with amyotrophic lateral sclerosis (ALS) have revealed a strong association between mutations in genes encoding many RNA-binding proteins (RBPs), including TARDBP, FUS, ...hnRNPA1, hnRNPA2B1, MATR3, ATXN2, TAF15, TIA-1, and EWSR1, and disease onset/progression. RBPs are a group of evolutionally conserved proteins that participate in multiple steps of RNA metabolism, including splicing, polyadenylation, mRNA stability, localization, and translation. Dysregulation of RBPs, as a consequence of gene mutations, impaired nucleocytoplasmic trafficking, post-translational modification, aggregation and sequestration by abnormal RNA foci, has been shown to be involved in neurodegeneration and the development of ALS. While the exact mechanism by which dysregulated RBPs contribute to ALS remains elusive, emerging evidence supports the notion that both a loss-of-function and/or a gain-of-toxic-function of these ALS-linked RBPs play a significant role in disease pathogenesis through facilitating abnormal protein interaction, causing aberrant RNA metabolism, and by disturbing ribonucleoprotein granule dynamics and phase transition. In this review, we summarize the current knowledge on the molecular mechanism by which RBPs are dysregulated and the influence of defective RBPs on cellular homeostasis during the development of ALS. The strategies of ongoing clinical trials targeting RBPs and/or relevant processes are also discussed in the present review.
Coxsackievirus B3 (CVB3) is a single-stranded positive RNA virus that usurps cellular machinery, including the evolutionarily anti-viral autophagy pathway, for productive infections. Despite the ...emergence of double-membraned autophagosome-like vesicles during CVB3 infection, very little is known about the mechanism of autophagy initiation. In this study, we investigated the role of established autophagy factors in the initiation of CVB3-induced autophagy. Using siRNA-mediated gene-silencing and CRISPR-Cas9-based gene-editing in culture cells, we discovered that CVB3 bypasses the ULK1/2 and PI3K complexes to trigger autophagy. Moreover, we found that CVB3-induced LC3 lipidation occurred independent of WIPI2 and the transmembrane protein ATG9 but required components of the late-stage ubiquitin-like ATG conjugation system including ATG5 and ATG16L1. Remarkably, we showed the canonical autophagy factor ULK1 was cleaved through the catalytic activity of the viral proteinase 3C. Mutagenesis experiments identified the cleavage site of ULK1 after Q524, which separates its N-terminal kinase domain from C-terminal substrate binding domain. Finally, we uncovered PI4KIIIβ (a PI4P kinase), but not PI3P or PI5P kinases as requisites for CVB3-induced LC3 lipidation. Taken together, our studies reveal that CVB3 initiates a non-canonical form of autophagy that bypasses ULK1/2 and PI3K signaling pathways to ultimately converge on PI4KIIIβ- and ATG5-ATG12-ATG16L1 machinery.
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