Vitamin D Enhances Immune Effector Pathways of NK Cells Thus Providing a Mechanistic Explanation for the Increased Effectiveness of Therapeutic Monoclonal Antibodies.

Patients with diffuse large cell lymphoma who have an adequate vitamin D supply derive significantly more benefit from immuno-chemotherapy with rituximab than patients with vitamin D deficiency; this is especially true for female patients. We have already been able to show that vitamin D increases the antibody-dependent cytotoxicity (ADCC) of NK cells in a sex-dependent manner, but it is unclear how vitamin D makes NK cells more efficient. METHODS: Healthy individuals with vitamin D deficiency were supplemented with vitamin D to sufficient levels. NK cells were isolated from blood samples before and after vitamin D saturation. For transcriptome analysis, we used the Affymetrix Gene-Chip 2.0™. Gene expression analysis as well as supervised and unsupervised pathway analysis were performed. RESULTS: Among others the "NK cell-associated cytotoxicity pathway" increased after vitamin D substitution. Five IFN-α subtypes (2, 4, 6, 7 and 10) and IFN-κ were more highly expressed and are mainly responsible in these pathways. In contrast, the pathway "interferon-gamma response", as well as other sets in cytokine production and chemotaxis showed a reduction. Toll-like receptor genes (TLR-8, TLR-7, TLR-2) were downregulated and, therefore, are responsible for the decline of these pathways. The same could be shown for the "ubiquitin-ligase" pathway. CONCLUSIONS: Increased expression of several IFN-α subtypes may explain the increased ADCC of NK cells in vitamin D-replenished and otherwise healthy subjects. Other regulators of interferon production and ADCC are compensatory upregulated in compensation, such as Toll-like receptors and those of the ubiquitin ligase, and normalize after vitamin D substitution.

Immune response and locoregional treatments for peritoneal carcinomatosis.

Peritoneal Carcinomatosis (PC) is considered as a terminal disease with short survival. It is treated with palliative therapies, consisting of repeated drainages and sometimes instillation of chemotherapy. Since the nineties, surgery has been combined with more effective systemic chemotherapy, intraperitoneal chemotherapy and hyperthermic intraperitoneal chemotherapy (HIPEC) for the treatment of PC. This combination therapy significantly increases the overall survival of selected PC patients. The understanding of how intraperitoneal chemotherapy and HIPEC can cure patients is still unclear. Experts hypothesized that the efficacy is obtained by the ability of high peritoneal drug exposure and hyperthermia to directly kill cancer cells. Several studies indicate that cancer cells death directly influences the response of the immune system. For this reason, the protective effect of intraperitoneal chemotherapy and HIPEC could be mediated by its ability to kill cancer cells in an immuno-genic way, causing an efficient anticancer immune response. In this review, we investigate the role of the innate peritoneal or locoregional therapy-induced immune response in PC therapy.

ROS-mediated time-varying cytotoxic effects on Phaeodactylum tricornutum under the stress of commercial naphthenic acids.

The aquatic toxicity and ecological risks of naphthenic acids (NAs) in marine environments have attracted an increasing amount of attention. However, there remains a lack of methodologies for the long-term risk assessment of NAs on marine ecosystems after high acid crude oil spill accidents. In this study, using the model microalgae Phaeodactylum tricornutum as the target object, the time-effect manner under NAs stress is investigated for a continuous 24-144 h. We found that: 1) NAs caused photosynthetic damage and persistent oxidative stress that slowed the growth rate and limited the maximum growth of P. tricornutum population within 24 h to 144 h of exposure, especially under the high concentration treatment; 2) Within 144 h, NAs can cause oxidative stress to P. tricornutum. The damage to cell membrane and radical oxidative species (ROS) accumulation of P. tricornutum were observed as obvious time-effect; 3) Under NAs stress, the two types of cell death (accidental cell death and regulated cell death) of P. tricornutum cell mediated by ROS played different roles in the population growth inhibition of P. tricornutum. Moreover, regulated cell death of the P. tricornutum cell was accompanied by PS externalization, DNA fragment and the G2/M phase stagnation acted as an adaptive regulatory mechanism under NAs stress. This explained the dose-time-effects of NAs on the population growth of P. tricornutum. Overall, the results suggested that NAs have a lasting effect on marine phytoplankton populations, and long-term risk assessments are required after high acid crude oil spill accidents. This is the first attempt to identify the different types of death at the cellular level to explain the time-effect toxicity at the population level of marine microalgae when exposed to NAs. This research will provide a new approach to facilitate further risk assessments for NAs and related contaminants in marine ecosystems.

Anti-PD-L1/TGFßR2 (M7824) fusion protein induces immunogenic modulation of human urothelial carcinoma cell lines, rendering them more susceptible to immune-mediated recognition and lysis.

BACKGROUND: Avelumab has recently been approved by the Food and Drug Administration for the therapy of Merkel cell carcinoma and urothelial carcinoma. M7824 is a novel first-in-class bifunctional fusion protein comprising a monoclonal antibody against programmed death-ligand 1 (PD-L1, avelumab), fused to the extracellular domain of human transforming growth factor beta (TGFß) receptor 2, which functions as a TGFß "trap." Advanced urothelial tumors have been shown to express TGFß, which possesses immunosuppressive properties that promote cancer progression and metastasis. The rationale for a combined molecule is to block the PD-1/PD-L1 interaction between tumor cells and immune cell infiltrate and simultaneously reduce or eliminate TGFß from the tumor microenvironment. In this study, we explored the effect of M7824 on invasive urothelial carcinoma cell lines. METHODS: Human urothelial (transitional cell) carcinoma cell lines HTB-4, HTB-1, and HTB-5 were treated with M7824, M7824mut (M7824 that is mutated in the anti-PD-L1 portion of the molecule and thus does not bind PD-L1), anti-PD-L1 (avelumab), or IgG1 isotype control monoclonal antibody, and were assessed for gene expression, cell-surface phenotype, and sensitivity to lysis by TRAIL, antigen-specific cytotoxic T lymphocytes and natural killer cells. RESULTS: M7824 retains the ability to mediate antibody-dependent cellular cytotoxicity of tumor cells, although in some cases to a lesser extent than anti-PD-L1. However, compared to anti-PD-L1, M7824 increases (A) gene expression of molecules involved in T-cell trafficking in the tumor (e.g., CXCL11), (B) TRAIL-mediated tumor cell lysis, and (C) antigen-specific CD8+ T-cell-mediated lysis of tumor cells. CONCLUSIONS: These studies demonstrate the immunomodulatory properties of M7824 on both tumor cell phenotype and immune-mediated lysis. Compared to anti-PD-L1 or M7824mut, M7824 induces immunogenic modulation of urothelial carcinoma cell lines, rendering them more susceptible to immune-mediated recognition and lysis. These findings show the relevance of the dual blockade of PD-L1 and TGFß in urothelial carcinoma cell lines and thus support the rationale for future clinical studies of M7824 in patients with urothelial cancer.

Effect of photobiomodulation on endothelial cell exposed to Bothrops jararaca venom.

Bleeding is a common feature in envenoming caused by Bothrops snake venom due to extensive damage to capillaries and venules, producing alterations in capillary endothelial cell morphology. It has been demonstrated, in vivo, that photobiomodulation (PBM) decreases hemorrhage after venom inoculation; however, the mechanism is unknown. Thus, the objective was to investigate the effects of PBM on a murine endothelial cell line (tEnd) exposed to Bothrops jararaca venom (BjV). Cells were exposed to BjV and irradiated once with either 660- or 780-nm wavelength laser light at energy densities of 4 and 5 J/cm(2), respectively, and irradiation time of 10 s. Cell integrity was analyzed by crystal violet and cell viability/mitochondrial metabolism by MTT assay. The release of lactic dehydrogenase (LDH) was quantified as a measure of cell damage. In addition, cytokine IL1-ß levels were measured in the supernatant. PBM at 660 and 780 nm wavelength was able to increase cellular viability and decrease the release of LDH and the loss of cellular integrity. In addition, the concentration of pro-inflammatory cytokine IL1-ß was reduced after PBM by both wavelengths. The data reported herein indicates that irradiation with red or near-infrared laser resulted in protection on endothelial cells after exposure to Bothrops venom and could be, at least in part, a reasonable explanation by the beneficial effects of PBM inhibiting the local effects induced by Bothrops venoms, in vivo.

Target-directed development and preclinical characterization of the proposed biosimilar rituximab GP2013.

Biosimilar development involves a target-directed iterative process to ensure a similar product to the originator. Here we report the preclinical development of the proposed biosimilar rituximab (GP2013). Post-translational modifications and bioactivities of GP2013 versus originator rituximab were engineered and monitored to ensure similar pharmacological profiles. Antibody-dependent cellular cytotoxicity (ADCC) was used to illustrate how different glycosylation patterns and structure-function relationships were controlled during process development. Pharmacological comparability between GP2013 and originator rituximab were confirmed in preclinical studies using clinical scale drug product. Similar in vitro ADCC potency was demonstrated when compared in a dose-response manner against two lymphoma cell lines using freshly purified human natural killer (NK) cells. In vivo efficacy was demonstrated in two well characterized mouse xenograft models, testing at sensitive sub-therapeutic dose levels. Pharmacokinetics and pharmacodynamics (CD20 cell depletion) were likewise comparable in cynomolgus monkeys. This preclinical comparability exercise confirms that GP2013 and originator rituximab are pharmacologically similar.

Hydrogel-based diffusion chip with Electric Cell-substrate Impedance Sensing (ECIS) integration for cell viability assay and drug toxicity screening.

In this study, we have provided a novel analytical integration between hydrogel-based cell chip and Electric Cell-substrate Impedance Sensing (ECIS) technique to apply to a high-throughput, real-time cell viability assay and drug screening. For simulating the drug diffusion model, we have developed a hydrogel-based tissue-mimicking structure with microfluidic channel, without unwanted flow, to generate a gradient concentration with long-term stability. Along the gradient line, four individual micro-electrodes were installed to record the impedance signal changes, which result from the cell viability under drug effects. By watching for cellular impedance changes, we successfully estimated the cytotoxicity of the treatment corresponding to the various concentration values of stimuli, generated by the diffusion process along the channel. Reliable IC50 values and time-dose relationships were also achieved. With the feature of real-time monitoring capability, the advantages of non-invasion, label-free detection, time saving and simple manipulation, our integrative device has become a promising high throughput cell-based on-chip platform for cell viability assay and drug screening.