Biology subjects

Bonfanti, P.

Publications and source records attributed to Bonfanti, P..

3 recordsLinked to original sources

bioRxiv2020

A cell atlas of human thymic development defines T cell repertoire formation

The thymus provides a nurturing environment for the differentiation and selection of T cells, a process orchestrated by their interaction with multiple thymic cell types. We utilised single-cell RNA-sequencing (scRNA-seq) to create a cell census of the human thymus and to reconstruct T-cell differentiation trajectories and T-cell receptor (TCR) recombination kinetics. Using this approach, we identified and located in situ novel CD8+ T-cell populations, thymic fibroblast subtypes and activated dendritic cell (aDC) states. In addition, we reveal a bias in TCR recombination and selection, which is attributed to genomic position and suggests later commitment of the CD8+ T-cell lineage. Taken together, our data provide a comprehensive atlas of the human thymus across the lifespan with new insights into human T-cell development.

immunology↗

bioRxiv2019

Engineering transplantable jejunal mucosal grafts using primary patient-derived organoids from children with intestinal failure

Intestinal failure (IF), following extensive anatomical or functional loss of small intestine (SI), has debilitating long-term effects on infants and children with this condition. Priority of care is to increase the childs length of functional intestine, jejunum in particular, to improve nutritional independence. Here we report a robust protocol for reconstruction of autologous intestinal mucosal grafts using primary IF patient materials. Human jejunal intestinal organoids derived from paediatric IF patients can be expanded efficiently in vitro with region-specific markers preserved after long-term culture. Decellularized human intestinal matrix with intact ultrastructure is used as biological scaffolds. Proteomic and Raman spectroscopic analyses reveal highly analogous biochemical composition of decellularized human SI and colon matrix, implying that they can both be utilised as scaffolds for jejunal graft reconstruction. Indeed, seeding of primary human jejunal organoids to either SI or colonic scaffolds in vitro can efficiently reconstruct functional jejunal grafts with persistent disaccharidase activity as early as 4 days after seeding, which can further survive and mature after transplantation in vivo. Our findings pave the way towards regenerative medicine for IF patients.

bioengineering↗

bioRxiv2019

Exposure during embryonic development to Roundup(R) Power 2.0 affects lateralization, level of activity and growth, but not defensive behaviour of marsh frog tadpoles

As glyphosate-based herbicides, sold under the commercial name Roundup(R), represent the most used herbicides in the world, contamination of the freshwater environment by glyphosate has become a widespread issue. In Italy, glyphosate was detected in half of the surface waters monitoring sites and its concentrations were higher than environmental quality standards in 24.5% of them. It can last from days to months in water, leading to exposure for aquatic organisms and specifically to amphibians larvae that develop in shallow water bodies with proven effects to development and behaviour. In this study, we tested the effects of a 96h exposure during embryonic development of marsh frogs tadpoles to three ecologically relevant Roundup(R) Power 2.0 concentrations. As expected, given the low concentrations tested, no mortality was observed. Morphological measurements highlighted a reduction in the total length in tadpoles exposed to 7.6 mg a.e./L, while an increase was observed at lower concentrations of 0.7 and 3.1 mg a.e./L compared to control group. Tadpoles raised in 7.6 mg a.e./L also showed a smaller tail membrane than those raised in the control solution. Regarding behaviour, we tested tadpoles in two different sessions (Gosner stages 25 and 28/29) for lateralization, antipredator response and basal activity. Lower intensity of lateralization was detected in tadpoles raised at the highest Roundup(R) concentration in the first session of observation, while no significant difference among treatments was observed in the second one. In both sessions, effects of glyphosate embryonic exposure on antipredator response, measured as the proportional change in activity after the injection of tadpole-fed predator (Anax imperator) cue, were not detected. Tadpoles exposed during embryonic development to Roundup(R) exhibited lower basal activity than the control group, with the strongest reduction for the 7.6 mg a.e./L treatment. Our results reinforce the concern of glyphosate contamination impact on amphibians.

zoology↗