The role of reactive oxygen species in the immunity induced by nano-pulse stimulation

Harnessing sulfur-doped carbon nanodots conjugated with IDO inhibitors act as a dual-mode breast cancer immunotherapy

Fluorescent ultrasmall nanoparticles (d < 10 nm), such as carbon nanodots (CDs), are promising nanosystems for precision cancer therapy. Their optimal size allows them to diffuse within complex microenvironments, enabling drug delivery, imaging, and monitoring. Additionally, CDs can be engineered to hold inherent nanotoxicity toward cancer cells, overcoming multidrug resistance associated with conventional drugs. Nevertheless, cancer is a multifactorial disease where combinational strategies are most likely to tackle metastatic tumors and efficiently avoid recidivism. Therefore, developing multifunctional CDs that exhibit intrinsic nanotoxicity against cancer cells and drive effective antitumor immune responses is a promising approach to improving patients' response rates. Here, we developed an innovative nanosystem by conjugating N-,S-doped CDs with indoximod (IND) through a simple and cost-effective method. Our CDs-IND not only retained the advantages of bare CDs, including photoluminescence for self-tracking but also significantly controlled breast cancer progression in vivo following CDs-IND intratumoral (IT) and intravenous (IV) administration. Tumor microenvironment (TME) immune profiling revealed that CDs-IND reduced IDO expression and recruited NK, NKT, and T cells. This study underscores the potential of combining the inherent pharmacological properties of CDs with indoximod-mediated immunotherapy, offering a promising strategy for precision breast cancer treatment.

A solution for highly efficient electroporation of primary cytotoxic T lymphocytes

BACKGROUND

Cytotoxic T lymphocytes (CTLs) are central players in the adaptive immune response. Their functional characterization and clinical research depend on efficient and reliable transfection. Although various methods have been utilized, electroporation remains the preferred technique for transient gene over-expression. However, the efficiency of electroporation is reduced for human and mouse primary CTLs. Lonza offers kits that effectively improve plasmid DNA transfection quality. Unfortunately, the removal of key components of the cell recovery medium considerably reduced the efficiency of their kit for CTLs. Our aim was to develop a new recovery medium to be used with Lonza's Nucleofector system that would significantly enhance transfection rates.

RESULTS

We assessed the impact of different media in which the primary CTLs were placed to recover after electroporation on cell survival, transfection rate and their ability to form an immunological synapse and to perform exocytosis. We transfected the cells with pmax-GFP and large constructs encoding for either CD81-super ecliptic pHluorin or granzyme B-pHuji. The comparison of five different media for mouse and two for human CTLs demonstrated that our new recovery medium composed of Opti-MEM-GlutaMAX supplemented with HEPES, DMSO and sodium pyruvate gave the best result in cell survival (> 50%) and transfection rate (> 30 and 20% for mouse and human cells, respectively). More importantly, the functionality of CTLs was at least twice as high as with the original Lonza recovery medium. In addition, our RM significantly improved transfection efficacy of natural killer cells that are notoriously hard to electroporate.

CONCLUSION

Our results show that successful transfection depends not only on the electroporation medium and pulse sequence but also on the medium applied for cell recovery. In addition, we have reduced our reliance on proprietary products by designing an effective recovery medium for both mouse and human primary CTLs and other lymphocytes that can be easily implemented by any laboratory. We expect that this recovery medium will have a significant impact on both fundamental and applied research in immunology.

Synergistic effects of nanosecond pulsed plasma and electric field on inactivation of pancreatic cancer cells in vitro

Nanosecond pulsed atmospheric pressure plasma jets (ns-APPJs) produce reactive plasma species, including charged particles and reactive oxygen and nitrogen species (RONS), which can induce oxidative stress in biological cells. Nanosecond pulsed electric field (nsPEF) has also been found to cause permeabilization of cell membranes and induce apoptosis or cell death. Combining the treatment of ns-APPJ and nsPEF may enhance the effectiveness of cancer cell inactivation with only moderate doses of both treatments. Employing ns-APPJ powered by 9 kV, 200 ns pulses at 2 kHz and 60-nsPEF of 50 kV/cm at 1 Hz, the synergistic effects on pancreatic cancer cells (Pan02) in vitro were evaluated on the metabolic activities of cells and transcellular electrical resistance (TER). It was observed that treatment with ns-APPJ for > 2 min disrupts Pan02 cell stability and resulted in over 30% cell death. Similarly, applying nsPEF alone, > 20 pulses resulted in over 15% cell death. While the inactivation activity from the individual treatment is moderate, combined treatments resulted in 80% cell death, approximately 3-to-fivefold increase compared to the individual treatment. In addition, reactive oxygen species such as OH and O were identified at the plasma-liquid interface. The gas temperature of the plasma and the temperature of the cell solution during treatments were determined to be near room temperature.

Abundance of reactive oxygen species (ROS) is associated with tumor aggressiveness, immune response, and worse survival in breast cancer

PURPOSE

Reactive oxygen species (ROS) are oxygen-containing molecules that have high reactivity and play roles in protection or harm the cancer cells. We aimed to clarify the clinical relevance of ROS in breast cancer (BC) tumor microenvironment (TME). We hypothesized that it is associated with worse BC patient outcomes.

METHODS

ROS score was generated by Gene Set Variation Analysis of Hallmark ROS pathway gene set and a total of 6245 BC patients were analyzed.

RESULTS

High ROS BC significantly enriched cell proliferation-related gene sets (MYC targets v1 and v2, G2M checkpoint, E2F targets), pro-cancer-related gene sets (DNA repair, unfolded protein response, MTORC1 signaling, PI3K/AKT/MTOR signaling, glycolysis, and oxidative phosphorylation), immune-related gene sets (inflammatory response, allograft rejection, interferon-α and γ responses, complement, and IL6/JAK/STAT3 signaling), and infiltrated immune cells (CD4⁺ memory and CD8⁺ T cells, Th1 and Th2, dendritic cells, Tregs, M1 and M2 macrophages) and B cells, as well as elevated cytolytic activity consistently in both METABRIC and GSE96058 cohorts. Cancer cells were the major source of ROS in BC TME of single-cell sequence (GSE75688) cohort. High ROS was associated with intratumor heterogeneity, homologous recombination defects, mutation rates, and neoantigens, and with clinical aggressiveness in AJCC stage, Nottingham grade and Ki67 expression, as well as worse overall survival in both GSE96058 and METABRIC, and with worse disease-specific survival in METABRIC.

CONCLUSION

Abundant ROS in BC patients is associated with abundant mutations, aggressive cancer biology, immune response, and worse survival.