The endophytic fungus Epichloë festucae is known to produce bioactive metabolites, which consequently protect the host plants from biotic and abiotic stresses. We previously found that the overexpression of vibA (a gene for transcription factor) in E. festucae strain E437 resulted in the secretion of an unknown fungicide. In the present study, the active substance was purified and chemically identified as ε-poly-L-lysine (ε-PL), which consisted of 28–34 lysine units. The productivity was 3.7-fold compared with that of the wild type strain E437. The isolated ε-PL showed inhibitory activity against the spore germination of the plant pathogens Drechslera erythrospila, Botrytis cinerea, and Phytophthora infestans at 1–10 μg/mL. We also isolated the fungal gene “epls” encoding ε-PL synthetase Epls. Overexpression of epls in the wild type strain E437 resulted in the enhanced production of ε-PL by 6.7-fold. Interestingly, overexpression of epls in the different strain E. festucae Fl1 resulted in the production of shorter ε-PL with 8–20 lysine, which exhibited a comparable antifungal activity to the longer one. The results demonstrate the first example of ε-PL synthetase gene from the eukaryotic genomes and suggest the potential of enhanced expression of vibA or/and epls genes in the Epichloë endophyte for constructing pest-tolerant plants.

The anti-invasive and anti-proliferative effects of betulins and abietane derivatives was systematically tested using an organotypic model system of advanced, castration-resistant prostate cancers. A preliminary screen of the initial set of 93 compounds was performed in two-dimensional (2D) growth conditions using non-transformed prostate epithelial cells (EP156T), an androgen-sensitive prostate cancer cell line (LNCaP), and the castration-resistant, highly invasive cell line PC-3. The 25 most promising compounds were all betulin derivatives. These were selected for a focused secondary screen in three-dimensional (3D) growth conditions, with the goal to identify the most effective and specific anti-invasive compounds. Additional sensitivity and cytotoxicity tests were then performed using an extended cell line panel. The effects of these compounds on cell cycle progression, mitosis, proliferation and unspecific cytotoxicity, versus their ability to specifically interfere with cell motility and tumor cell invasion was addressed. To identify potential mechanisms of action and likely compound targets, multiplex profiling of compound effects on a panel of 43 human protein kinases was performed. These target de-convolution studies, combined with the phenotypic analyses of multicellular organoids in 3D models, revealed specific inhibition of AKT signaling linked to effects on the organization of the actin cytoskeleton as the most likely driver of altered cell morphology and motility.

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e20046 Background: Clinical studies of liso-cel show low incidences of severe CRS and NEs. Pts with high tumor burden and inflammation are at higher risk of CRS and NEs (Borrega, Hemasphere 2019). Here, we characterize the presenting symptoms, timing, and management of CRS and NEs in pts with R/R LBCL treated with liso-cel in TRANSCEND NHL 001 (NCT02631044). A deeper understanding of CRS/NEs after liso-cel treatment may help clinicians identify and manage these toxicities. Methods: Pts with R/R LBCL and ≥2 lines of therapy received liso-cel after lymphodepletion (LD) with fludarabine and cyclophosphamide. Bridging therapy was allowed for pts with PET-positive disease before LD (Abramson, ASH 2019 #241). Investigators were educated on prospectively identifying liso-cel–related NEs and CRS, which were collected and graded per NCI CTCAE v4.03 (NEs) or 2014 Lee criteria (CRS). Timing and severity of individual CRS/NE symptoms and interventions were also collected. Results: The analysis included 269 pts (median age, 63 y): 38% had sum of perpendicular diameters ≥50 cm2 or lactate dehydrogenase ≥500 U/L, and 59% received bridging therapy. CRS and NEs had delayed onset (median, 5 and 9 d, respectively) and a low incidence of grade (Gr) ≥3 events (CRS 2%; NE 10%). CRS occurred before NEs in most pts and was Gr 1/2 at onset in all but 2 pts (Table). The most common CRS symptoms were pyrexia (40%), hypotension (20%), and tachycardia (18%). Overall, 20% of pts received tocilizumab and/or corticosteroids for CRS (10% tocilizumab only; 2% corticosteroids only; 8% both); 3% received vasopressors. The most common NE symptoms were confusional state (11%), tremor (9%), and aphasia (8%); most were low grade. A total of 17% of pts received tocilizumab and/or corticosteroids for NEs (13% corticosteroids only; < 1% tocilizumab only; 3% both); < 1% received vasopressors. Overall, 4% of pts were admitted to the ICU for CRS and/or NEs. Additional analyses on timing of intervention and type/severity of initial symptoms will be presented. Conclusions: In pts with high-risk, aggressive R/R LBCL, liso-cel treatment was associated with a low incidence of severe CRS/NEs, late onset of mostly low-grade events at presentation, and low use of tocilizumab/corticosteroids. Clinical trial information: NCT02631044 . [Table: see text]