Triptolide promotes differentiation of human monocytes into immunosuppressive MDSCs.

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) negatively modulate immune activity. Prior investigations have shown much promise in using MDSCs-assisted immunotherapy for organ transplantation patients. Additionally, owing to its immunosuppressive activity, MDSCs can also be used to manage immune-associated disorders. METHODS: Granulocyte-macrophage colony-stimulating factor (GM-CSF) was employed to stimulate myeloid progenitor cell differentiation. Triptolide (PG490) was introduced toward the later phases of in vitro MDSCs induction. Lastly, real-time PCR (RT-PCR) and flow cytometry were used to assess transcript expression and cell phenotype, and a mouse skin transplantation model was established to evaluate the MDSCs-mediated immune suppression in vivo. RESULTS: Co-stimulation with PG490 and GM-CSF potently induced myeloid-derived monocytes to form MDSCs, with remarkable immune-suppressive activity. The underlying mechanism involved downregulation of T cell proliferation, activation, enhancement of inflammatory cytokine release, as well as T cell conversion to Treg cells. PG490 strongly enhanced iNOS expression in MDSCs, and iNOS inhibition successfully reversed the immune-suppression. The PG490- and GM-CSF-induced MDSCs substantially extended survival duration of murine skin grafts, thereby validating their strong immune-suppressive activity in vivo. CONCLUSIONS: Herein, we presented a new approach involving MDSCs-based immunosuppression in vitro. PG490 and GM-CSF co-treatment strongly induced immuno-suppressive activity in MDSCs both in vitro and in vivo. Our findings highlight the promise of applying MDSCs-based therapy in clinical organ transplantation treatment.

PMA induces the differentiation of monocytes into immunosuppressive MDSCs.

The induction of immune tolerance without the use of immunosuppressive drugs is a crucial problem in organ transplantation. The use of myeloid-derived suppressor cells (MDSCs) as a cell-based adjuvant immunosuppressive therapy is a bright clinical prospect in organ transplantation. MDSCs with stable immunosuppressive activities can be used to treat immune-related diseases. In this study, macrophage colony-stimulating factor (M-CSF) was used to promote myeloid progenitor cell differentiation, and phorbol 12-myristate 13-acetate (PMA) was added to induce MDSCs at the later stage of induction in vitro. Cell phenotypes were detected by flow cytometry and mRNA was detected by real-time-polymerase chain reaction (RT-PCR). A mouse skin transplantation model was used to investigate the cell inhibitory function. The combination of PMA and M-CSF induced the differentiation of myeloid-derived monocytes into MDSCs. MDSCs were found to induce immune tolerance by inhibiting the proliferation and activation of T cells, promoting cytokine secretion and inducing T cell transformation to regulatory T cells (Treg ). PMA significantly up-regulated the expression of Arg-1 and the Arg-1 protein expression in MDSCs and arginase 1 (Arg-1) inhibitor nor-NOHA reversed the MDSC immunosuppressive activity, indicating the involvement of the Arg-1 pathway in MDSC-mediated immunosuppression. M-CSF + PMA-induced MDSCs also significantly prolonged the survival time of skin grafts in mice, showing that MDSCs exert immunosuppressive effects in vivo. We describe a novel scheme to induce immunosuppressive MDSCs in vitro. MDSCs induced by M-CSF with PMA showed stable immunosuppression. MDSCs induced by this protocol may benefit patients with organ transplantation through immune regulation.

Bluetongue Viruses Act as Novel Oncolytic Viruses to Effectively Inhibit Human Renal Cancer Cell Growth In Vitro and In Vivo.

BACKGROUND The bluetongue virus (BTV) is the prototype virus in the genus Orbivirus within the family Reoviridae. Recent studies indicate that BTVs are capable of infecting and selectively lysing human hepatic carcinoma cells (Hep-3B) and prostate carcinoma cells (pc-3). This study was designed to evaluate the oncolytic potential of BTV in experimental models of human renal cancer in vitro and in vivo. MATERIAL AND METHODS Five human renal cancer cell lines, ACHN, CAKI-1, OS-RC-2, 786-O, and A498, were used in this study to analyze BTV replication. These cells were lysed by oncolysis compared to normal control. Xenograft models were used to assess the efficacy and toxicity of BTVs in vivo. Data were analyzed by one-way ANOVA or two-sided unpaired t tests. RESULTS The results showed HPTEC cells to be relatively resistant to cytotoxic effects of BTVs and exhibited normal growth rate even at high dose of BTVs. Nonetheless, the renal cancer cells showed a remarkably higher sensitivity to BTVs. Moreover, the ultramicroscopic subcellular changes were also detected in the renal cells. The viral particles were observed in all the RCC cell lines, but not in HPTEC cells. Intratumoral injections of BTVs significantly decreased the tumor volume as compared to animals that received no virus treatment. Infection with BTVs significantly increased the percentage of apoptotic renal cancer cells but not the HPTEC cells. Moreover, BTV triggered apoptosis in renal cancer cells via a mitochondria-mediated pathway. CONCLUSIONS This study for the first time demonstrated the oncolytic potential of BTV in experimental models of human renal cancer. BTV exhibits the potential to inhibit human renal cancer cell growth in vitro and in vivo.

LINC02532 Contributes to Radiosensitivity in Clear Cell Renal Cell Carcinoma through the miR-654-5p/YY1 Axis.

BACKGROUND: Studies have shown that long non-coding RNAs (lncRNAs) play essential roles in tumor progression and can affect the response to radiotherapy, including in clear cell renal cell carcinoma (ccRCC). LINC02532 has been found to be upregulated in ccRCC. However, not much is known about this lncRNA. Hence, this study aimed to investigate the role of LINC02532 in ccRCC, especially in terms of radioresistance. METHODS: Quantitative real-time PCR was used to detect the expression of LINC02532, miR-654-5p, and YY1 in ccRCC cells. Protein levels of YY1, cleaved PARP, and cleaved-Caspase-3 were detected by Western blotting. Cell survival fractions, viability, and apoptosis were determined by clonogenic survival assays, CCK-8 assays, and flow cytometry, respectively. The interplay among LINC02532, miR-654-5p, and YY1 was detected by chromatin immunoprecipitation and dual-luciferase reporter assays. In addition, in vivo xenograft models were established to investigate the effect of LINC02532 on ccRCC radioresistance in 10 nude mice. RESULTS: LINC02532 was highly expressed in ccRCC cells and was upregulated in the cells after irradiation. Moreover, LINC02532 knockdown enhanced cell radiosensitivity both in vitro and in vivo. Furthermore, YY1 activated LINC02532 in ccRCC cells, and LINC02532 acted as a competing endogenous RNA that sponged miR-654-5p to regulate YY1 expression. Rescue experiments indicated that miR-654-5p overexpression or YY1 inhibition recovered ccRCC cell functions that had been previously impaired by LINC02532 overexpression. CONCLUSIONS: Our results revealed a positive feedback loop of LINC02532/miR-654-5p/YY1 in regulating the radiosensitivity of ccRCC, suggesting that LINC02532 might be a potential target for ccRCC radiotherapy. This study could serve as a foundation for further research on the role of LINC02532 in ccRCC and other cancers.

Bexarotene Induce Differentiation of Myeloid-Derived Suppressor Cells through Arg-1 Signalling Pathway.

BACKGROUND: Cellular therapy has emerged as a promising strategy to minimize the use of conventional immunosuppressive drugs and ultimately induce long-term graft survival. Myeloid-derived suppressor cells (MDSCs) can be used for immunosuppressive treatment of solid organ transplants. METHODS: Granular macrophage colony-stimulating factor (GM-CSF) and bexarotene, an X receptor-selective retinoid, were used for in vitro MDSC induction. Cell phenotypes were detected using flow cytometry, while mRNA was detected via real-time PCR. A mouse skin transplantation model was used to verify the inhibitory effects of this treatment. RESULTS: The combination of GM-CSF and bexarotene-induced MDSC differentiation. MDSCs induce immune tolerance by inhibiting T-cell proliferation, influencing cytokine secretion, and inducing T-cell transformation into Treg cells. Combination treatment significantly up-regulated Arg-1 expression in MDSCs. The Arg-1 inhibitor nor-NOHA neutralized the immunosuppressive activity of MDSCs, suggesting the involvement of Arg-1 in MDSC-mediated immunosuppression. GM-CSF and bexarotene-induced MDSCs prolong graft survival in mouse skin transplants, exhibiting in vivo immunosuppressive effects. CONCLUSIONS: A new method for inducing MDSCs is presented. The combination of GM-CSF and bexarotene induces MDSCs with remarkable regulatory functions. Adoptive transfer of the induced MDSCs extended allograft survival. These results suggest that MDSCs can potentially be used in future clinical transplants to inhibit rejection, reduce adverse events, and induce operative tolerance.

Hepatotoxicity Associated with Immune Checkpoint Inhibitors in Clinical Practice: A Study Leveraging Data from the US Food and Drug Administration's Adverse Event Reporting System.

PURPOSE: Immune checkpoint inhibitors (ICIs) are a promising option for the treatment of patients with various cancers. Emerging case reports have raised awareness on hepatotoxicity, a potentially fatal adverse event (AE) that may be associated with the use of ICIs. This study assessed the potential association between ICIs and hepatotoxicity through the mining of data from the US Food and Drug Administration's AE Reporting System (FAERS). METHODS: A total of 9,217,181 AEs reported in the period from quarter 1 of 2004 to quarter 3 of 2021 were assessed. Information components (ICs) and reporting odds ratios (RORs) were used to evaluate the association between the use of ICIs and hepatotoxicity. FINDINGS: A total of 52,463 AE reports listed ICIs, used alone or in combination, as a suspected drug. Of these, 1481 cases were related to both ICIs and hepatotoxicity. The use of ICIs was significantly associated with hepatotoxicity compared to all other drugs, making it a safety signal (IC = 1.43 [95% CI, 1.36-1.51]; ROR = 2.78 [95% CI, 2.64-2.93]). With monotherapy, all ICIs, except tremelimumab, were associated with liver damage. The most commonly prescribed combination therapy was nivolumab + ipilimumab (321 cases) with a significant signal detected. Notably, ICI use was significantly associated with hepatic failure (IC = 1.24 [95% CI, 1.06-1.42]; ROR = 2.40 [95% CI, 2.13-2.72]). The risk for ICI-associated hepatotoxicity (including hepatic failure) was greater with ICI combination therapy than with ICI monotherapy. All subgroups by sex and age also showed significant associations between ICI use and hepatotoxicity. IMPLICATIONS: A significant association was detected between ICI use and hepatotoxicity. The risk for hepatotoxicity (including hepatic failure) was greater with ICI combination therapy compared with ICI monotherapy.

Drone-Based Harvest Data Prediction Can Reduce On-Farm Food Loss and Improve Farmer Income.

On-farm food loss (i.e., grade-out vegetables) is a difficult challenge in sustainable agricultural systems. The simplest method to reduce the number of grade-out vegetables is to monitor and predict the size of all individuals in the vegetable field and determine the optimal harvest date with the smallest grade-out number and highest profit, which is not cost-effective by conventional methods. Here, we developed a full pipeline to accurately estimate and predict every broccoli head size (n > 3,000) automatically and nondestructively using drone remote sensing and image analysis. The individual sizes were fed to the temperature-based growth model and predicted the optimal harvesting date. Two years of field experiments revealed that our pipeline successfully estimated and predicted the head size of all broccolis with high accuracy. We also found that a deviation of only 1 to 2 days from the optimal date can considerably increase grade-out and reduce farmer's profits. This is an unequivocal demonstration of the utility of these approaches to economic crop optimization and minimization of food losses.

M-CSF and prostratin induced Mregs promote immune tolerance in transplanted mice through Arg-1 pathway.

OBJECTIVE: Regulatory macrophages (Mregs) are a group of heterogeneous macrophages. These cells could induce immunosuppressive effects through the expression of immune regulatory molecules and cytokines. METHODS: The differentiation of Mregs was induced by treating bone marrow cells with M-CSF and prostratin in vitro. The cell-phenotypes and immunosuppressive function were determined by flow cytometry. Rt-PCR was employed to assess the mechanisms of Mregs. Skin grafted mouse model was used for in vivo validation. RESULTS: Mregs induced by M-CSF + prostratin had a strong inhibitory effect on T cell proliferation and cytokines production. The phenotype of induced bone marrow cells changed towards Mregs. These Mregs could induce the differentiation of Tregs in vivo. Arg-1 expression in these cells were significantly upregulated. Inhibition of arginase (Arg) or arginine supplement significantly reversed the immunosuppressive function. In mice skin-grafted models, adoptive transfer of these Mregs significantly prolonged allograft survival. In mice models, Arg-1 expression significantly elevated on skin grafts cells and Tregs increased in graft tissues. CONCLUSIONS: We successfully developed a Mregs-inducing protocol with the combination of M-CSF and prostratin in vitro. M-CSF + prostratin induced Mregs prevented mice skin graft rejection through upregulating the expression Arg-1.

SARS-CoV-2 Seroprevalence and Profiles Among Convalescents in Sichuan Province, China.

Objectives: To explore and understand the SARS-CoV-2 seroprevalence of convalescents, the association between antibody levels and demographic factors, and the seroepidemiology of convalescents of COVID-19 till March 2021. Methods: We recruited 517 voluntary COVID-19 convalescents in Sichuan Province and collected 1,707 serum samples till March 2021. Then we reported the seroprevalence and analyzed the associated factors. Results: Recent travel history was associated with IgM levels. Convalescents who had recent travel history were less likely to be IgM antibody negative [OR = 0.232, 95% CI: (0.128, 0.420)]. Asymptomatic cases had, approximately, twice the odds of being IgM antibody negative compared with symptomatic cases [OR = 2.583, 95% CI: (1.554, 4.293)]. Participants without symptoms were less likely to be IgG seronegative than those with symptoms [OR = 0.511, 95% CI: (0.293, 0.891)]. Convalescents aged 40-59 were less likely to be IgG seronegative than those aged below 20 [OR = 0.364, 95% CI: (0.138, 0.959)]. The duration of positive IgM antibodies persisted 365 days while the IgG persisted more than 399 days. Conclusions: Our findings suggested that recent travel history might be associated with the antibody levels of IgM, while age could be associated with the antibody levels of IgG. Infection type could be associated with both antibody levels of IgM and IgG that declined quicker in asymptomatic cases.

Global Wheat Head Detection 2021: An Improved Dataset for Benchmarking Wheat Head Detection Methods.

The Global Wheat Head Detection (GWHD) dataset was created in 2020 and has assembled 193,634 labelled wheat heads from 4700 RGB images acquired from various acquisition platforms and 7 countries/institutions. With an associated competition hosted in Kaggle, GWHD_2020 has successfully attracted attention from both the computer vision and agricultural science communities. From this first experience, a few avenues for improvements have been identified regarding data size, head diversity, and label reliability. To address these issues, the 2020 dataset has been reexamined, relabeled, and complemented by adding 1722 images from 5 additional countries, allowing for 81,553 additional wheat heads. We now release in 2021 a new version of the Global Wheat Head Detection dataset, which is bigger, more diverse, and less noisy than the GWHD_2020 version.

Kidney transplantation improves arterial stiffness in patients with end-stage renal disease.

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of mortality among the patients with end-stage renal disease (ESRD). Arterial stiffness is a well-accepted predictor of cardiovascular mortality in general population and ESRD patients. The aim of this study was to compare the change of arterial stiffness in kidney transplant recipients (KTRs) and ESRD patients, and further investigate the impact of kidney transplantation (KT) on arterial stiffness. METHODS: A total of 138 maintenance hemodialysis patients, 198 KTRs and 75 healthy volunteers were enrolled in this study. The carotid-femoral pulse wave velocity (CF-PWV) and carotid-radial PWV (CR-PWV) were determined, and the correlations of PWV with biochemical parameters were analyzed. RESULTS: CF-PWV was highest in the maintenance hemodialysis patients, but similar between KTRs and healthy volunteers. Bivariate correlation analysis among KTRs demonstrated that CF-PWV was positively correlated with high level of peripheral diastolic blood pressure, pulse pressure, mean artery pressure, BUN and HDL, but negatively correlated with albumin. Univariate polytomous logistic regression analysis showed that age, BMI, systolic blood pressure, pulse pressure, length of KT and BUN were associated with the increase of CF-PWV value. CONCLUSIONS: Aortic stiffness could be improved after KT. Meanwhile, age, BMI, systolic blood pressure, pulse pressure, length of KT and BUN were independent predictors of the increase of CF-PWV in KTRs.