A review of wheat diseases—a field perspective Figueroa, Melania; Hammond‐Kosack, Kim E.; Solomon, Peter S.
Molecular plant pathology,
June 2018, Letnik:
19, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Summary
Wheat is one of the primary staple foods throughout the planet. Significant yield gains in wheat production over the past 40 years have resulted in a steady balance of supply versus demand. ...However, predicted global population growth rates and dietary changes mean that substantial yield gains over the next several decades will be needed to meet this escalating demand. A key component to meeting this challenge is better management of fungal incited diseases, which can be responsible for 15%–20% yield losses per annum. Prominent diseases of wheat that currently contribute to these losses include the rusts, blotches and head blight/scab. Other recently emerged or relatively unnoticed diseases, such as wheat blast and spot blotch, respectively, also threaten grain production. This review seeks to provide an overview of the impact, distribution and management strategies of these diseases. In addition, the biology of the pathogens and the molecular basis of their interaction with wheat are discussed.
Methylation of the MGMT gene promoter is associated with a favorable prognosis in adult patients with GBM treated with TMZ. We determined the incidence of pseudoprogression according to the MGMT ...methylation status and the potential value of DSC perfusion MR images for predicting pseudoprogression.
New or enlarged enhancing lesions after CCRT in adult patients with newly diagnosed GBMs were prospectively assessed by measuring their rCBV by using DSC perfusion MR images. Tumor tissue was assayed to determine MGMT promoter methylation status. All patients were regularly followed up at an interval of 2 months by MR images, including DSC perfusion MR images.
Ninety eligible patients were enrolled in this study. After CCRT, new or enlarged enhanced lesions were found in 59 of 90 patients, which were subsequently classified as pseudoprogression (26 patients, 28.9%) and real progression (33 patients, 36.7%). Overall, there was a significant difference in the mean rCBV between pseudoprogression and real tumor progression (P = .003). The ROC curve revealed that an rCBV ratio >1.47 had an 81.5% sensitivity and a 77.8% specificity. The unmethylated MGMT promoter group had a significant difference of mean rCBV between pseudoprogression and real progression (P = .009), though the methylated MGMT promoter group had no significant difference (P = .258).
The current study suggests that rCBV measured by DSC perfusion MR images has a differential impact on the predictability of pseudoprogression in patients with GBM.
Efficient delivery of tumor antigens and immunostimulatory adjuvants into lymph nodes is crucial for the maturation and activation of antigen-presenting cells (APCs), which subsequently induce ...adaptive antitumor immunity. A dissolving microneedle (MN) has been considered as an attractive method for transcutaneous immunization due to its superior ability to deliver vaccines through the stratum corneum in a minimally invasive manner. However, because dissolving MNs are mostly prepared using water-soluble sugars or polymers for their rapid dissolution in intradermal fluid after administration, they are often difficult to formulate with poorly water-soluble vaccine components. Here, we develop amphiphilic triblock copolymer-based dissolving MNs in situ that generate nanomicelles (NMCs) upon their dissolution after cutaneous application, which facilitate the efficient encapsulation of poorly water-soluble Toll-like receptor 7/8 agonist (R848) and the delivery of hydrophilic antigens. The sizes of NMCs range from 30 to 40 nm, which is suitable for the efficient delivery of R848 and antigens to lymph nodes and promotion of cellular uptake by APCs, minimizing systemic exposure of the R848. Application of MNs containing tumor model antigen (OVA) and R848 to the skin of EG7-OVA tumor-bearing mice induced a significant level of antigen-specific humoral and cellular immunity, resulting in significant antitumor activity.
Tumor-specific mutations form novel immunogenic peptides called neoantigens. Neoantigens can be used as a biomarker predicting patient response to cancer immunotherapy. Although a predicted binding ...affinity (IC50) between peptide and major histocompatibility complex class I is currently used for neoantigen prediction, large number of false-positives exist.
We developed Neopepsee, a machine-learning-based neoantigen prediction program for next-generation sequencing data. With raw RNA-seq data and a list of somatic mutations, Neopepsee automatically extracts mutated peptide sequences and gene expression levels. We tested 14 immunogenicity features to construct a machine-learning classifier and compared with the conventional methods based on IC50 regarding sensitivity and specificity. We tested Neopepsee on independent datasets from melanoma, leukemia, and stomach cancer.
Nine of the 14 immunogenicity features that are informative and inter-independent were used to construct the machine-learning classifiers. Neopepsee provides a rich annotation of candidate peptides with 87 immunogenicity-related values, including IC50, expression levels of neopeptides and immune regulatory genes (e.g. PD1, PD-L1), matched epitope sequences, and a three-level (high, medium, and low) call for neoantigen probability. Compared with the conventional methods, the performance was improved in sensitivity and especially two- to threefold in the specificity. Tests with validated datasets and independently proven neoantigens confirmed the improved performance in melanoma and chronic lymphocytic leukemia. Additionally, we found sequence similarity in proteins to known pathogenic epitopes to be a novel feature in classification. Application of Neopepsee to 224 public stomach adenocarcinoma datasets predicted ∼7 neoantigens per patient, the burden of which was correlated with patient prognosis.
Neopepsee can detect neoantigen candidates with less false positives and be used to determine the prognosis of the patient. We expect that retrieval of neoantigen sequences with Neopepsee will help advance research on next-generation cancer immunotherapies, predictive biomarkers, and personalized cancer vaccines.
The cancer stem cell (CSC) hypothesis has important clinical implications for cancer therapeutics because of the proposed role of CSCs in chemoresistance. The aim of this study was to investigate ...changes in the CSC populations before and after primary systemic therapy (PST) and their prognostic role in human breast cancer.
Paired samples (before and after PST) of breast cancer tissue were obtained from clinical stage II or III patients (n=92) undergoing PST with the regimen of doxorubicin plus docetaxel (AD) (n=50) or doxorubicin plus cyclophosphamide (AC) (n=42) and subsequent breast resection. The proportions of putative CSCs with CD44+/CD24- or aldehyde dehydrogenase 1+ (ALDH1+) phenotypes were determined by immunohistochemistry.
A higher proportion of CD44+/CD24- tumour cells and ALDH1 positivity in pre-chemotherapy tissue was correlated with higher histologic grade, oestrogen receptor (ER) negativity, high Ki-67 proliferation index and basal-like subtype of breast cancer. Aldehyde dehydrogenase 1 positivity in pre-chemotherapy biopsy was also associated with a higher rate of pathologic complete response following PST. In comparisons of putative CSC populations before and after PST, the proportions of CD44+/CD24- and ALDH1+ tumour cells were significantly increased after PST. The cases with increased CD44+/CD24- tumour cell populations after PST showed high Ki-67 proliferation index in post-chemotherapy specimens and those with increased ALDH1+ tumour cell population after PST were associated with ER negativity and p53 overexpression. Furthermore, cases showing such an increase had significantly shorter disease-free survival time than those with no change or a reduced number of CSCs, and the survival difference was most notable with regard to the changes of ALDH1+ tumour cell population in the patients who received AC regimen.
The present study provides the clinical evidence that the putative CSCs in breast cancer are chemoresistant and are associated with tumour progression, emphasising the need for targeting of CSCs in the breast cancer therapeutics.
Tumour-infiltrating lymphocytes (TILs) are known to be associated with response to primary systemic therapy (PST) in breast cancer. This study was conducted to assess the association of TIL subsets ...with pathological complete response (pCR) after PST in breast cancer in relation to breast cancer subtype, breast cancer stem cell (BCSC) phenotype and epithelial-mesenchymal transition (EMT).
The pre-chemotherapeutic biopsy specimens of 153 breast cancer patients who underwent surgical resection after anthracycline- or anthracycline/taxane-based PST were analysed. TIL subsets (CD4+, CD8+, and FOXP3+ TILs), BCSC phenotype, and the expression of EMT markers were evaluated by immunohistochemistry and were correlated with pCR after PST.
Infiltration of CD4+ and CD8+ T lymphocytes was closely correlated with BCSC phenotype and EMT. High levels of CD4+, CD8+, and FOXP3+ TILs were associated with pCR, and CD8+ TILs were found to be an independent predictive factor for pCR. In addition, CD8+ TILs were associated with pCR irrespective of breast cancer subtype, CD44+/CD24- phenotype, EMT, and chemotherapeutic regimen in subgroup analyses.
These findings indicate that CD8+ cytotoxic T lymphocytes are a key component of TILs associated with chemo-response and can be used as a reliable predictor of response to anthracycline- or anthracycline/taxane-based PST in breast cancer.