Biology subjects

Filippi, E.

Publications and source records attributed to Filippi, E..

3 recordsLinked to original sources

bioRxiv2025

Single-cell chromatin landscape and DNA methylation patterns reveal shared molecular programs in human tumor and non-tumor tissue CCR8+ Treg cells

Regulatory T (Treg) cells, a subset of CD4+ T cells, play a crucial role in immunoregulation. Notably, CCR8-expressing Treg cells in tissues also contribute to organ homeostasis and repair. To determine whether these tissue-regenerative programs are active in the tumor microenvironment, we employed single-cell chromatin accessibility and genome-wide DNA methylation analyses to investigate CCR8+ tissue Treg cells isolated from human tumor and adjacent tumor-free tissues. Our findings indicate that CCR8+ tissue Treg cells from tumor and corresponding tumor-free tissues exhibit a high degree of similarity, suggesting that the tumor microenvironment may harbor highly activated tissue Treg cells. This observation was consistent across various tumor types and origins, including primary tumors and metastases. Using quantitative proteomics, we identified several candidate factors associated with the regenerative and suppressive programs of Treg cells, which may serve as potential reservoir of druggable targets for future therapeutic interventions.

immunology↗

bioRxiv2019

Seasonal microbial dynamics on grapevine leaves under biocontrol and copper fungicide treatments

Winemakers have long used copper as a fungicide on grapevine. However, the potential of copper to accumulate on soil and affect the biota poses a challenge to achieving sustainable agriculture. One recently developed option is the use of biocontrol agents to replace or complement traditional methods. In the present study, a field experiment was conducted in South Africa in which the leaves in two blocks of a vineyard were periodically treated with either copper sulphate or sprayed with Lactobacillus plantarum MW-1 as a biocontrol agent. This study evaluated the impact of the two treatments on the bacterial and fungal communities as they changed during the growing season. To do this, NGS was combined with quantitative strain-specific and community qPCRs. The results revealed the progression of the microbial communities throughout the season and how the different treatments affected the microbiota. Bacteria appeared to be relatively stable at the different time points, with the only taxa that systematically changed between treatments being Lactobacillaceae, which included reads from the biocontrol agent. Cells of Lactobacillus plantarum MW-1 were only detected on treated leaves using strain-specific qPCR, with its amount spanning from 103to 105cells/leaves. Conversely the fungal community was largely shaped by a succession of different dominant taxa over the months. Between treatments, only a few fungal taxa appeared to change significantly and the number of ITS copies was also comparable. In this regards, the two treatments seemed to affect the microbial community similarly, revealing the potential of this biocontrol strain as a promising alternative among sustainable fungicide treatments, although further investigation is required.

microbiology↗

bioRxiv2018

Quantitative and qualitative evaluation of the impact of the G2 enhancer, bead sizes and lysing tubes on the bacterial community composition during DNA extraction from recalcitrant soil core samples based on community sequencing and qPCR

Soil DNA extraction encounters numerous challenges that can affect both yield and purity of the recovered DNA. Clay particles lead to reduced DNA extraction efficiency, and PCR inhibitors from the soil matrix can negatively affect downstream analyses when applying DNA sequencing. Further, these effects impede molecular analysis of bacterial community compositions in lower biomass samples, as often observed in deeper soil layers. Many studies avoid these complications by using indirect DNA extraction with prior separation of the cells from the matrix, but such methods introduce other biases that influence the resulting microbial community composition.\n\nTo address these issues, a direct DNA extraction method was applied in combination with the use of a commercial product, the G2 DNA/RNA Enhancer(R), marketed as being capable of improving the amount of DNA recovered after the lysis step. The results showed that application of G2 increased DNA yields from the studied clayey soils from layers between 1.00 and 2.20 m below ground level.\n\nImportantly, the use of G2 did not introduce bias, as it did not result in any significant differences in the biodiversity of the bacterial community measured in terms of alpha and beta diversity and taxonomical composition.\n\nFinally, this study considered a set of customised lysing tubes for evaluating possible influences on the DNA yield. Tubes customization included different bead sizes and amounts, along with lysing tubes coming from two suppliers. Results showed that the lysing tubes with mixed beads allowed greater DNA recovery compared to the use of either 0.1 or 1.4 mm beads, irrespective of the tube supplier.\n\nThese outcomes may help to improve commercial products in DNA/RNA extraction kits, besides raising awareness about the optimal choice of additives, offering opportunities for acquiring a better understanding of topics such as vertical microbial characterisation and environmental DNA recovery in low biomass samples.

microbiology↗