Liposome Vaccine for Active Regulation of Cellular and Humoral Immunity.

Despite significant progress in vaccine development, especially in the fight against viral infections, many unexplored areas remain including innovative adjuvants, diversification of vaccine formulations, and research into the coordination of humoral and cellular immune mechanisms induced by vaccines. Effective coordination of humoral and cellular immunity is crucial in vaccine design. In this study, we used the spike protein (S) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or ovalbumin (OVA) as antigen models and CpG DNA (an activator of toll-like receptor 9, TLR9) as an adjuvant to prepare a multitargeted liposome (LIPO) vaccine. Once equipped with the ability to target lymph nodes (LN) and the endoplasmic reticulum (ER), the LIPO vaccine significantly enhances the cross-presentation ability of antigen-presenting cells (APCs) for exogenous antigens through the ER-associated protein degradation (ERSD) mechanism. Additionally, the vaccine could fine-tune the efficiency of ER-targeted antigen delivery, actively regulating the presentation of exogenous antigen proteins via the major histocompatibility complex (MHC-I) or MHC-II pathways. Immune data from in vivo mouse experiments indicated that the LIPO vaccine effectively stimulated both humoral and cellular immune responses. Furthermore, it triggers immune protection by establishing a robust and persistent germinal center. Moreover, the multifunctionality of this LIPO vaccine extends to the fields of cancer, viruses, and bacteria, providing insights for skilled vaccine design and improvement.

Oxygen nanocarrier broke the hypoxia trap of solid tumors and rescued transfection efficiency for gene therapy.

BACKGROUND: Gene therapy shows great promise for a broad array of diseases. However, we found that hypoxic tumor microenvironment (TME) exerted significant inhibitory effects on transfection efficiency of a variety of gene vectors (such as Lipo 2000 and PEI) in an oxygen-dependent manner. Solid tumors inevitably resulted in acute hypoxic areas due to the rapid proliferation of tumor cells and the aberrant structure of blood vessels. Thus, the hypoxic TME severely limited the efficiency and application of gene therapy. METHODS: In our previous study, we constructed endoplasmic reticulum-targeted cationic liposomes, PAR-Lipo, which could effectively deliver genes and ensure high transfection efficiency under normoxia. Unsatisfactorily, the transfection efficiency of PAR-Lipo was rather poor under hypoxia. We believed that reoxygenation was the most direct and effective means to rescue the low transfection under hypoxia. Hence, we fabricated liposomes modified with perfluorooctyl bromide (PFOB@Lipo) to load oxygen and deliver it to tumor sites, which effectively alleviated the hypoxic nature of tumor. Then PAR-Lipo were applied to mediate high-efficiency delivery of tumor suppressor gene pTP53 to inhibit tumor progression. RESULTS: The results showed that such staged strategy augmented the expression of P53 protein in tumors and extremely suppressed tumor growth. CONCLUSION: This work was the first attempt to utilize an oxygen nanocarrier to assist the therapeutic effect of gene therapy under hypoxia, providing a new reference for gene therapy in malignant tumors. GRAPHICAL ABSTARCT.

Causal effects of genetically predicted testosterone on Alzheimer's disease: a two-sample mendelian randomization study.

OBJECTIVE: Although several studies have reported that testosterone may protect against Alzheimer's disease, no evidence of a causal relationship has been demonstrated. METHODS: A Mendelian randomization (MR) study was performed to determine the causal role of testosterone in Alzheimer's disease. The study utilized public databases obtained from separately published genome-wide associationstudies (GWAS). Single-nucleotide polymorphisms (SNPs) for testosterone were extracted from the most recent and largest published GWAS meta-analysis (178,782 participants), and SNPs for Alzheimer's disease were extracted from UK Biobank (954 AD cases and 487,331 controls). The odds ratio (OR) of the inverse variance weighting (IVW) approach was the primary outcome, and the weighted median and MR Egger regression were used for sensitivity analysis. RESULTS: Through IVW, we observed a causal association between genetically predicted testosterone and the risk of Alzheimer's disease, with an OR of 0.99 (95% confidence interval [CI] = 0.998-0.999, p = 0.047). In the sensitivity analyses, the weighted median regression showed directionally similar estimates (OR = 0.99, 95% CI = 0.998-0.999, p = 0.048). The MR Egger regression showed similar estimates (OR = 0.99, 95% CI = 0.998-1.00, p = 0.35), but with lower precision. Funnel plots, MR Egger intercepts, and Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) analysis indicated the absence of directional pleiotropy effects. CONCLUSION: In conclusion, our MR study provides evidence of a causal relationship between testosterone levels and Alzheimer's disease; however, this relationship must be validated in future studies with larger sample sizes. Early testosterone monitoring may enable the prevention of Alzheimer's and related diseases.

Neutrophil hitchhiking for drug delivery to the bone marrow.

Pharmaceuticals have been developed for the treatment of a wide range of bone diseases and disorders, but suffer from problematic delivery to the bone marrow. Neutrophils are naturally trafficked to the bone marrow and can cross the bone marrow-blood barrier. Here we report the use of neutrophils for the targeted delivery of free drugs and drug nanoparticles to the bone marrow. We demonstrate how drug-loaded poly(lactic-co-glycolic acid) nanoparticles are taken up by neutrophils and are then transported across the bone marrow-blood barrier to boost drug concentrations in the bone marrow. We demonstrate application of this principle to two models. In a bone metastasis cancer model, neutrophil delivery is shown to deliver cabazitaxel and significantly inhibit tumour growth. In an induced osteoporosis model, neutrophil delivery of teriparatide is shown to significantly increase bone mineral density and alleviate osteoporosis indicators.

ER-Targeting PDT Converts Tumors into In Situ Therapeutic Tumor Vaccines.

A therapeutic tumor vaccine is a promising approach to cancer treatment. One of its strategies is to treat patient-derived tumor cells in vitro and then administer them in vivo to induce an adaptive immune response and achieve cancer treatment. Here, we want to explore the possibility of converting cancer tissue into a therapeutic tumor vaccine through induced immunogenic cell death (ICD) in situ. We loaded indocyanine green (ICG) into liposomes (ICG-Lipo) and modified it with the pardaxin peptide to realize an endoplasmic reticulum (ER)-targeting function (Par-ICG-Lipo). A microfluidic technique was developed for loading ICG, a water-soluble molecule, into liposomes with a high encapsulation efficiency (greater than 90%). Under near-infrared (NIR) irradiation, ER-targeting photodynamic therapy (PDT) induced by Par-ICG-Lipo could promote the release of danger-signaling molecules (DAMPs) and tumor antigens (TAAs) in vivo, which significantly enhanced the immunogenicity in vivo and thus stimulates a strong antitumor immune response. This process would be further amplified by adopting dendritic cells. In general, our strategy transformed in situ tumor cells into therapeutic vaccines by ER-targeting PDT, which could provide a clinically applicable and effective approach for cancer treatment.

Rational administration sequencing of immunochemotherapy elicits powerful anti-tumor effect.

As a research hotspot, immune checkpoint inhibitors (ICIs) is often combined with other therapeutics in order to exert better clinical efficacy. To date, extensive laboratory and clinical investigations into the combination of ICIs and chemotherapy have been carried out, demonstrating augmented effectiveness and broad application prospects in anti-tumor therapy. However, the administration of these two treatment modalities is usually randomized or fixed to a given chronological order. Nevertheless, the pharmacological effect of drug is closely related to its exposure behavior in vivo, which may consequently affect the synergistic outcomes of a combined therapy. In this study, we prepared a lipid nanoparticle encapsulating docetaxel (DTX-VNS), and associated it with the immune checkpoint inhibitor anti-PD-1 antibody (αPD-1) for the treatment of malignant tumors. To identify the optimum timing and sequencing for chemotherapy and immunotherapy, we designed three administration regimes, including the simultaneous delivery of DTX-VNS and αPD-1(DTX-VNS@αPD-1), DTX-VNS delivery before (DTX-VNS plus αPD-1) or post (αPD-1 plus DTX-VNS) PD-1 blockade with an interval of two days. Analysis from mass spectrometry, multi-factor detection and other techniques indicated that DTX-VNS plus αPD-1 initiated a powerful anti-tumor response in multiple tumor models, contributing to a remarkably reshaped tumor microenvironment landscape, which may attribute to the maximum therapeutic additive effects arise from a concomitant exposure of DTX-VNS and αPD-1 at the tumor site. By profiling the exposure kinetics of nanoparticles and αPD-1 in vivo, we defined the administration schedule with utmost therapeutic benefits, which may provide a valuable clinical reference for the rational administration of immunochemotherapy.

Targeting DNA to the endoplasmic reticulum efficiently enhances gene delivery and therapy.

Gene therapy mediated by non-viral carriers is gaining an increasing popularity due to its high biosafety and the convenience of production on a large scale, yet inefficient gene delivery is a limiting obstacle. Few gene vectors can avoid the endosome-lysosome route, and as a result, their DNA payloads are easily decomposed during transfection. Herein, a peptide (pardaxin, PAR)-modified cationic liposome (PAR-Lipo) targeting the endoplasmic reticulum (ER) was developed for improving the gene delivery efficiency. Interestingly, compared to non-PAR-modified cationic liposomes (Non-Lipos) and Lipofectamine 2000 (Lipo 2000, a commercial genetic vector), PAR-Lipos showed remarkably higher gene delivery efficiency in vitro and better antitumor efficacy in vivo. It was demonstrated that PAR-Lipos could be accumulated into the ER via a non-lysosome intracellular route after cellular internalization, which induced the retention of the DNA payload in the ER close to the nucleus, while Non-Lipos, like most conventional cationic carriers, mainly presented lysosomal retention after their endocytosis. The unique intracellular transport behavior of PAR-Lipos can enhance the protection of the DNA payload, prolong their residence time in the cell, and promote their entry into the nucleus relying on the intimate relationship between the ER and nuclear membrane, which is the explanation for the enhanced gene-therapy effect mediated by PAR-Lipos. Our research may provide alternative means of efficiently delivering genes in cells.

Extremely Effective Chemoradiotherapy by Inducing Immunogenic Cell Death and Radio-Triggered Drug Release under Hypoxia Alleviation.

Local hypoxia in solid malignancies often results in resistance to radiotherapy (RT) and chemotherapy (CT), which may be one of the main reasons for their failure in clinical application. Especially, oxygen is an essential element for enhancing DNA damage caused by ionizing radiation in radiotherapy. Here, two biomimetic oxygen delivery systems were designed by encapsulating hemoglobin (Hb) alone into a liposome (Hb-Lipo) or co-encapsulating Hb and doxorubicin (DOX) into a liposome (DOX-Hb-Lipo). Our data indicated that both Hb-Lipo and DOX-Hb-Lipo could effectively alleviate hypoxia in tumors. We demonstrated that RT plus tumor-targeting delivery of oxygen mediated by Hb-Lipo could significantly overcome the tolerance of hypoxic cancer cells to RT, showing significantly enhanced cancer-cell killing and tumor growth inhibition ability, mainly attributing to hypoxia alleviation and increased reactive oxygen species production under RT in cancer cells. Furthermore, a melanoma model that was quite insensitive to both RT and CT was used to test the efficacy of chemoradiotherapy combined with hypoxia alleviation. RT plus Hb-Lipo only caused a limited increase in antitumor activity. However, extremely strong tumor inhibition could be obtained by RT combined with DOX-Hb-Lipo-mediated CT, attributed to radio-triggered DOX release and enhanced immunogenic cell death induced by RT under an oxygen supplement. Our study provided a valuable reference for overcoming hypoxia-induced radioresistance and a useful therapeutic strategy for cancers that are extremely insensitive to chemo- or radiotherapy.

Laser Immunotherapy in Combination with Perdurable PD-1 Blocking for the Treatment of Metastatic Tumors.

A convenient and feasible therapeutic strategy for malignant and metastatic tumors was constructed here by combining photothermal ablation (PTA)-based laser immunotherapy with perdurable PD-1 blockade immunotherapy. Hollow gold nanoshells (HAuNS, a photothermal agent) and AUNP12 (an anti PD-1 peptide, APP) were co-encapsulated into poly(lactic- co-glycolic) acid (PLGA) nanoparticles. Unlike monoclonal PD-1/PD-L1 antibodies, PD-1 peptide inhibitor shows lower cost and immunotoxicity but needs frequent administration due to its rapid clearance in vivo. Our data here showed that the formed HAuNS- and APP-loaded PLGA nanoparticles (AA@PN) could maintain release periods of up to 40 days for the peptide, and a single intratumoral injection of AA@PN could replace the frequent administration of free APP. After the administration of AA@PN and irradiation with a near-infrared laser at the tumor site, an excellent killing effect on the primary tumor cells was achieved by the PTA. The nanoparticles also played a vaccine-like role under the adjuvant of cytosine-phospho-guanine (CpG) oligodeoxynucleotide and generated a localized antitumor-immune response. Furthermore, sustained APP release with laser-dependent transient triggering could induce the blockage of PD-1/PD-L1 pathway to activate T cells, thus subsequently generating a systemic immune response. Our data demonstrated that the PTA combined with perdurable PD-1 blocking could efficiently eradicate the primary tumors and inhibit the growth of metastatic tumors as well as their formation. The present study provides a promising therapeutic strategy for the treatment of advanced cancer with metastasis and presents a valuable reference for obtaining better outcomes in clinical cancer immunotherapy.

Hypoxic tumor therapy by hemoglobin-mediated drug delivery and reversal of hypoxia-induced chemoresistance.

Chemotherapy has become a critical treatment for many cancer types. However, its efficacy is hindered by chemoresistance and limited drug accumulation induced by the hypoxic tumor environment. Therefore, there is an urgent need for useful strategies to alleviate tumor hypoxia and enhance chemotherapy response in solid tumors. Herein, we report the development of a multifunctional liposome simultaneously loading an oxygen carrier (hemoglobin, Hb) and an anti-tumor drug (doxorubicin, DOX) to enhance chemotherapeutic effects against hypoxic tumors. The liposomes, DOX-Hb-lipo (DHL), showed efficient loading of oxygen and site-specific oxygen delivery into tumors, inducing the reversal of tumor hypoxia. Furthermore, the O2 interference capacity increased the uptake of the drug into hypoxic cancer cells, inducing a remarkably increased toxicity of the drug against cancer cells. Interestingly, the obtained DHL showed a significantly enhanced internalization into cancer cells and accumulation in tumors compared to DL (DOX loaded liposomes without Hb), while the enhanced effect did not occur in normal cells. The specific delivery of DHL into cancer cells should be attributed to the mediation of Hb on the surface of the liposomes. In addition, DHL considerably increased reactive oxygen species (ROS) production in a hypoxic environment and promoted the ROS-mediated cytotoxicity of DOX. Based on the elevated drug accumulation in the tumor sites, increased internalization into cancer cells and enhanced oxygen levels in tumor regions, DHL reversed hypoxia-induced chemoresistance and exhibited stronger antitumor effects. Thus, DHL might be a promising alternative strategy for cancer treatment.