In lab settings, inbred mouse strains like BALB/c, C57BL/6J, and C57BL/6N are commonly used. Research in immunology and infectious diseases indicates that their Th1 and Th2 immune responses differ. However, the specific differences in the immune response to the vaccination still require investigation. In this study, ovalbumin (OVA) was used as an antigen and CpG-enriched recombinant plasmid (pUC18-CpG) as an adjuvant for immunisation. The level of serum-specific antibody IgG was detected by indirect ELISA. At 35dpi, serum cytokine levels were measured using MILLIPLEX®. T lymphocyte clusters from mouse spleen were examined using flow cytometry to investigate the immunological effects of the CPG-OVA vaccine on three different types of mice. The results showed that pUC18-CpG as an adjuvant could successfully enhance the immune response. BALB/c had the highest level of IgG antibody. In the OVA-only group, the CD4+/CD8+ ratio of the three types of mice was generally increased, and the BALB/c group had the highest ratio. After inoculation with CpG-OVA, the CD4+/CD8+ ratio of the three types of mice was lower than that of the OVA-only group, and C57BL/6J was the lowest. Compared with the CpG-OVA group of the three kinds of mice, the levels of Th2 cytokines IL-6 and IL-10 in BALB/c were increased compared with C57BL/6J and C57BL/6N. After OVA, the six cytokines secreted in C57BL/6J were higher than those in the C57BL/6N OVA group. Therefore, C57 is a better model for examining the function of the vaccine in cellular immunity, whereas BALB/c mice are more prone to humoral immunity. In addition to highlighting the CpG plasmid\'s ability to successfully activate the immune response of Th1 and Th2, as well as the expression of IgG in vivo and promote T cell immune typing, this study provides valuable insights into immunology and the selection of mouse models for infectious diseases, providing a valuable resource for designing more effective vaccines in the future.

BACKGROUND: Triple-negative breast cancer (TNBC) is a recurrent, heterogeneous, and invasive form of breast cancer. The treatment of TNBC patients with paclitaxel and fluorouracil in a sequential manner has shown promising outcomes. However, it is challenging to deliver these chemotherapeutic agents sequentially to TNBC tumors. We aim to explore a precision therapy strategy for TNBC through the sequential delivery of paclitaxel and fluorouracil.
METHODS: We developed a dual chemo-loaded aptamer with redox-sensitive caged paclitaxel for rapid release and non-cleavable caged fluorouracil for slow release. The binding affinity to the target protein was validated using Enzyme-linked oligonucleotide assays and Surface plasmon resonance assays. The targeting and internalization abilities into tumors were confirmed using Flow cytometry assays and Confocal microscopy assays. The inhibitory effects on TNBC progression were evaluated by pharmacological studies in vitro and in vivo.
RESULTS: Various redox-responsive aptamer-paclitaxel conjugates were synthesized. Among them, AS1411-paclitaxel conjugate with a thioether linker (ASP) exhibited high anti-proliferation ability against TNBC cells, and its targeting ability was further improved through fluorouracil modification. The fluorouracil modified AS1411-paclitaxel conjugate with a thioether linker (FASP) exhibited effective targeting of TNBC cells and significantly improved the inhibitory effects on TNBC progression in vitro and in vivo.
CONCLUSIONS: This study successfully developed fluorouracil-modified AS1411-paclitaxel conjugates with a thioether linker for targeted combination chemotherapy in TNBC. These conjugates demonstrated efficient recognition of TNBC cells, enabling targeted delivery and controlled release of paclitaxel and fluorouracil. This approach resulted in synergistic antitumor effects and reduced toxicity in vivo. However, challenges related to stability, immunogenicity, and scalability need to be further investigated for future translational applications.

A cancer-targeted glutathione (GSH)-gated theranostic probe (CGT probe) for intracellular miRNA imaging and combined treatment of self-sufficient starvation therapy (ST) and chemodynamic therapy (CDT) was developed. The CGT probe is constructed using MnO2 nanosheet (MS) as carrier material to adsorb the elaborately designed functional DNAs. It can be internalized by cancer cells via specific recognition between the AS1411 aptamer and nucleolin. After CGT probe entering the cancer cells, the overexpressed GSH, as gate-control, can degrade MS to Mn2+ which can be used for CDT by Fenton-like reaction. Simultaneously, Mn2+-mediated CDT can further cascade with the enzyme-like activities (catalase-like activity and glucose oxidase-like activity) of CGT probe, achieving self-sufficient ST/CDT synergistic therapy. Meanwhile, the anchored DNAs are released, achieving in situ signal amplification via disubstituted-catalytic hairpin assembly (DCHA) and FRET (fluorescence resonance energy transfer) imaging of miR-21. The in vitro and in vivo experiments demonstrated that accurate and sensitive miRNA detection can be achieved using the CGT probe. Overall, the ingenious CGT probe opens a new avenue for the development of early clinical diagnosis and cancer therapy.

Remarkable progress has been made in tumour immunotherapy in recent decades. However, the clinical outcomes of therapeutic interventions remain unpredictable, largely because of inefficient immune responses. To address this challenge and optimise immune stimulation, we present a novel administration route for enhancing the bioavailability of immunotherapeutic drugs. Our approach involves the development of an oral tumour vaccine utilising virus-like particles derived from the Hepatitis B virus core (HBc) antigen. The external surfaces of these particles are engineered to display the model tumour antigen OVA, whereas the interiors are loaded with cytosine phosphoguanosine oligodeoxynucleotide (CpG ODN), resulting in a construct called CpG@OVAHBc with enhanced antigenicity and immune response. For oral delivery, CpG@OVAHBc is encapsulated in a crosslinked dextran hydrogel called CpG@OVAHBc@Dex. The external hydrogel shield safeguards the biomimetic virus particles from degradation by gastric acid and proteases. Upon exposure to intestinal flora, the hydrogel disintegrates, releasing CpG@OVAHBc at the intestinal mucosal site. Owing to its virus-like structure, CpG@OVAHBc exhibits enhanced adhesion to the mucosal surface, facilitating uptake by microfold cells (M cells) and subsequent transmission to antigen-presenting cells. The enzyme-triggered release of this oral hydrogel ensures the integrity of the tumour vaccine within the digestive tract, allowing targeted release and significantly improving bioavailability. Beyond its efficacy, this oral hydrogel vaccine streamlines drug administration, alleviates patient discomfort, and enhances treatment compliance without the need for specialised injection methods. Consequently, our approach expands the horizons of vaccine development in the field of oral drug administration.

Hepatocyte growth factor receptor (c-Met) is a suitable molecular target for the targeted therapy of cancer. Novel c-Met-targeting drugs need to be developed because conventional small-molecule inhibitors and antibodies of c-Met have some limitations. To synthesize such drugs, we developed a bispecific DNA nanoconnector (STPA) to inhibit c-Met function. STPA was constructed by using DNA triangular prism as a scaffold and aptamers as binding molecules. After c-Met-specific SL1 and nucleolin-specific AS1411 aptamers were integrated with STPA, STPA could bind to c-Met and nucleolin on the cell membrane. This led to the formation of the c-Met/STPA/nucleolin complex, which in turn blocked c-Met activation. In vitro experiments showed that STPA could not only inhibit the c-Met signaling pathways but also facilitate c-Met degradation through lysosomes. STPA also inhibited c-Met-promoted cell migration, invasion, and proliferation. The results of in vivo experiments showed that STPA could specifically target to tumor site in xenograft mouse model, and inhibit tumor growth with low toxicity by downregulating c-Met pathways. This study provided a novel and simple strategy to develop c-Met-targeting drugs for the targeted therapy of cancer.

The simultaneous delivery of CpG oligonucleotide along with short interfering RNA (siRNA) has the potential to significantly boost the anticancer impact of siRNA medications. Our previous research demonstrated that Curdlan nanoparticles functionalized with adenosine are capable of selectively delivering therapeutic siRNA to cancerous cells through endocytosis mediated by adenosine receptors. Herein, we synthesized a dual-ligand-functionalized Curdlan polymer (denoted by CuMAN) to simultaneously target tumor cells and tumor-associated macrophages (TAMs). CuMAN nanoparticles containing CpG and siRNA demonstrated enhanced uptake by B16F10 tumor cells and bone marrow-derived macrophages, which are facilitated by AR on tumor cells and mannose receptor on macrophages. This led to increased release of pro-inflammatory cytokines in both in vitro and in vivo settings. The synergistic effect of CpG on TAMs and RNAi on tumor cells mediated by the CuMAN nanoparticle not only suppressed the tumor growth but also strongly inhibited the lung metastasis. Our findings indicate that the CuMAN nanoparticle has potential as an effective dual-targeting delivery system for nucleic acid therapeutics.

Aggressive nature of colon cancer and current imprecise therapeutic scenarios simulate the development of precise and effective treatment strategies. To achieve this, a tumor environment-activated photosensitized biomimetic nanoplatform (PEG2000-SiNcTI-Ph/CpG-ZIF-8@CM) is fabricated by encapsulating metal-organic framework loaded with developed photosensitizer PEG2000-SiNcTI-Ph and immunoadjuvant CpG oligodeoxynucleotide within fusion cell membrane expressing programmed death protein 1 (PD-1) and cluster of differentiation 47 (CD47). By stumbling across, systematic evaluation, and deciphering with quantum chemical calculations, a unique attribute of tumor environment (low pH plus high concentrations of adenosine 5\'-triphosphate (ATP))-activated photodynamic effect sensitized by long-wavelength photons is validated for PEG2000-SiNcTI-Ph/CpG-ZIF-8@CM, advancing the precision of cancer therapy. Moreover, PEG2000-SiNcTI-Ph/CpG-ZIF-8@CM evades immune surveillance to target CT26 colon tumors in mice mediated by CD47/signal regulatory proteins α (SIRPα) interaction and PD-1/programmed death ligand 1 (PD-L1) interaction, respectively. Tumor environment-activated photodynamic therapy realized by PEG2000-SiNcTI-Ph/CpG-ZIF-8@CM induces immunogenic cell death (ICD) to elicit anti-tumor immune response, which is empowered by enhanced dendritic cells (DC) uptake of CpG and PD-L1 blockade contributed by the nanoplatform. The photodynamic immunotherapy efficiently combats primary and distant CT26 tumors, and additionally generates immune memory to inhibit tumor recurrence and metastasis. The nanoplatform developed here provides insights for the development of precise cancer therapeutic strategies.

As a highly contagious opportunistic pathogen, Pseudomonas aeruginosa (P. aeruginosa) is one of the main causes of healthcare-associated infections. The drug-resistant nature of P. aeruginosa can render antibiotic treatments ineffective, leading to a high morbidity and mortality. Higher specificity and reduced toxicity are features of immunotherapy, which can generate robust immune responses and preserve long-term immunological memory to completely eradicate infections. In this study, we developed a type of P. aeruginosa vaccine based on a metal-organic framework. Specifically, MIL-101-Al nanoparticles were synthesized to encapsulate antigens derived from the bacterial lysate (BL) of PAO1, a drug-resistant P. aeruginosa, and the adjuvant unmethylated cytosine-phosphate-guanine oligonucleotide (CpG), which were then modified with palmitic acid (PAA) to obtain MIL-BC@PAA. The stability and biocompatibility were significantly increased by capping with PAA. Moreover, MIL-BC@PAA showed significantly enhanced uptake by antigen presenting cells (APCs), and promoted their maturation. Importantly, immunity studies revealed the greatly elicited antigen-specific humoral and cellular responses, and a protection rate of about 70% was observed in P. aeruginosa-challenged mice. Overall, these results demonstrate the promising potential of MIL-BC@PAA as an ideal nanovaccine for P. aeruginosa vaccination.

The interaction between glioma cells and astrocytes promotes the proliferation of gliomas. Micro-RNAs (miRNAs) carried by astrocyte exosomes (exos) may be involved in this process, but the mechanism remains unclear. The oligonucleotide AS1411, which consists of 26 bases and has a G-quadruplex structure, is an aptamer that targets nucleolin. In this study, we demonstrate exosome-miRNA-27a-mediated cross-activation between astrocytes and glioblastoma and show that AS1411 reduces astrocytes\' pro-glioma activity. The enhanced affinity of AS1411 toward nucleolin is attributed to its G-quadruplex structure. After binding to nucleolin, AS1411 inhibits the entry of the NF-κB pathway transcription factor P65 into the nucleus, then downregulates the expression of miRNA-27a in astrocytes surrounding gliomas. Then, AS1411 downregulates astrocyte exosome-miRNA-27a and upregulates the expression of INPP4B, the target gene of miRNA-27a in gliomas, thereby inhibiting the PI3K/AKT pathway and inhibiting glioma proliferation. These results were verified in mouse orthotopic glioma xenografts and human glioma samples. In conclusion, the parallel structure of AS1411 allows it to bind to nucleolin and disrupt the exosome-miRNA-27a-mediated reciprocal activation loop between glioma cells and astrocytes. Our results may help in the development of a novel approach to therapeutic modulation of the glioma microenvironment.

Proteolysis-targeting chimeras (PROTACs) are heterobifunctional molecules consisting of two ligands joined by a linker, enabling them to simultaneously bind with an E3 ligase and a protein of interest (POI) and trigger proteasomal degradation of the POI. Limitations of PROTAC include lack of potent E3 ligands, poor cell selectivity, and low permeability. AS1411 is an antitumor aptamer specifically recognizing a membrane-nucleus shuttling nucleolin (NCL). Here, we repurpose AS1411 as a ligand for an E3 ligase mouse double minute 2 homolog (MDM2) via anchoring the NCL-MDM2 complex. Then, we construct an AS1411-NCL-MDM2-based PROTAC (ANM-PROTAC) by conjugating AS1411 with large-molecular-weight ligands for \"undruggable\" oncogenic STAT3, c-Myc, p53-R175H, and AR-V7. We show that the ANM-PROTAC efficiently penetrates tumor cells, recruits MDM2 and degrades the POIs. The ANM-PROTAC achieves tumor-selective distribution and exhibits excellent antitumor activity with no systemic toxicity. This is a PROTAC with built-in tumor-targeting and cell-penetrating capacities.