In the context of hematopoietic cell transplantation, hematopoietic stem cells and progenitor cells (HSC and HPC) are usually collected by apheresis following their mobilization by G-CSF alone or in ...combination with Plerixafor® when patients fail to respond to G-CSF alone. In medical practice, the quality of the hematopoietic graft is based on CD34
cell content that is used to define "Good Mobilizer (GM)" or "Poor Mobilizer (PM)" patients but does not report the real HSC content of grafts. In this study, we assessed the HSC content within the CD34
fraction of graft samples from 3 groups of patients: 1-GM patients receiving G-CSF only (GM
), 2-PM patients receiving G-CSF only (PM
), 3-PM patients receiving G-CSF + Plerixafor (PM
). Although HSC from the 3 groups of patients displayed very similar phenotypic profiles, expression of "stemness" genes and metabolic characteristics, their capacity to engraft NSG mice differed revealing differences in terms of HSC between groups. Indeed according to mobilization regimen, we observed differences in migration capacity of HSC, as well as differences in engraftment intensity depending on the initial pathology (myeloma versus lymphoma) of patients. This suggests that mobilization regimen could strongly influence the long term engraftment efficiency of hematopoietic grafts.
Introduction
No randomized controlled clinical trial of therapeutic plasma exchanges (TPE) has yet been performed for moderate‐to‐severe relapses of multiple sclerosis (MS).
Objective
To compare TPE ...to sham‐TPE in patients with a recent steroid‐resistant moderate‐to‐severe MS relapse.
Methods
Patients presenting with an MS relapse of less than 2 months without improvement and 15 days after a course of steroids were randomized. Specific criteria were used for each relapse type to define moderate‐to‐severe disability. The primary endpoint was the proportion of patients with at least a moderate improvement based on objective and functional evaluation after 1 month.
Results
Thirty‐eight patients were randomized. The intention‐to‐treat analysis included 14 patients in the TPE group and 17 in the Sham‐TPE group. The proportion of patients with at least moderate improvement at 1 month did not differ between the groups (P = .72), although 57.1% of the TPE group had full recovery compared with 17.6% of the sham group. Considering optic neuritis (ON), a significant difference in the proportion of different levels of improvement was observed in favor of the TPE group (P = .04). The combined Kurtzke's functional systems scores were significantly more improved in the TPE group than in the sham‐TPE group at months 1 (P < .01), 3 (P < .05), and 6 (P < .05). No major side effects were observed.
Conclusions
A significant difference between TPE and Sham‐TPE at the primary endpoint was only observed in patients with ON. Neurological function improved significantly more often in the TPE group than in the sham‐TPE group.
Les cellules souches hématopoïétiques (CSH) CD34+ autologues issues de sang périphérique sont collectées par aphérèse. La leucocytose (L) influence l’efficacité de collecte (EC). Nous comparons l‘EC ...et d’autres variables entre les kits 10110 Terumo-BCT® et P1YA Fresenius-Kabi®, dans deux groupes comparables de patients adultes, puis dans deux focus groupes en cas de L<10G/L.
Par une étude rétrospective monocentrique, nous comparons (Mann et Whitney) les variables des collectes de CSH autologues sur 10110® et P1YA®̊: données du patient, compte de CD34 précollecte, quantité de CD34 collectées, volume collecté, volume sanguin total traité, temps de collecte, numération formule sanguine avant et après collecte, EC, teneur en polynucléaires neutrophiles (PnN) et érythrocytes (GR) du greffon.
Cent trente-neuf procédures sur 10110® dont 19 avec L<10G/L sont comparées à 68 procédures sur P1YA® dont 21 avec L<10G/L. Les moyennes d’EC sont les mêmes dans les deux groupes (12,6 %±0,5 vs. 13,9 %±0,7) (p=0,07), mais diminuent significativement pour 10110® et se maintiennent pour P1YA® (9,7 %+/1,1 vs. 14,1 %±1,4) (p=0,01) en cas de L<10G/L. Aucune différence significative de teneur en PNN n’est observée entre 10110® et P1YA® quelle que soit L (21,3 %±1,68 vs. 22,3 %±2,04, p=0,29 et 37,2 %±5 ;69 vs. 25,5 %±4,19, p=0,14). La teneur en GR du greffon avec 10110® est significativement inférieure à P1YA® quelle que soit L (0,22T/L±0,01 vs. 0,47T/L±0,04, p<0,0001 et 0,27T/L±0,05 vs. 0,45T/L±0,06, p=0,002).
P1YA® maintient son efficacité en cas de L<10G/L sans augmentation du taux de PNN mais avec un taux de GR du greffon plus important (Figures 1–3 et Tableau 1).
Ce travail a pour but d’évaluer et comparer la qualité du contenu en Cellules Souches Hématopoïétiques (CSH) au sein de la fraction CD34+ de greffons mobilisés par G-CSF seul ou en association avec ...le Plerixafor : patients Bons Mobilisateurs ayant reçu uniquement du G-CSF (BMG-CSF) et patients Mauvais Mobilisateurs ayant reçu du G-CSF seul (MMG-CSF) ou en association avec du Plerixafor (MMG-CSF+P). Afin de cibler au mieux les CSH au sein de la population CD34+ des greffons, nous utilisons une stratégie d’approche directe appelée « Side Population (SP) ». Nos résultats indiquent une proportion plus faible de cellules CD34+/SP chez les MMG-CSF que chez les BMG-CSF mais qui est restaurée chez les MMG-CSF+P. Le même phénomène est observé pour les sous-populations de cellules CD34+/SP de phénotype CD38low/CD133+/CD90+. Les cellules CD34+/SP des patients MMG-CSF ont également une activité mitochondriale diminuée par rapport aux patients BMG-CSF restaurée chez les patients MMG-CSF+P. Sur le plan fonctionnel, les cellules CD34+/SP des greffons ont une capacité équivalente, quelles que soient les conditions de mobilisation, à produire in vitro des cellules érythroïdes, myéloïdes et lymphoïdes B. En revanche la capacité de greffe (test Scid Repopulating Cells) des cellules CD34+/SP des patients BMG-CSF et MMG-CSF+P diffère en fonction de la pathologie initiale des patients, et la capacité de homing semble impactée chez les patients mauvais mobilisateurs. Nos Résultats indiquent donc que l’association du phénotype SP au critère CD34 permet une évaluation plus précise du contenu en CSH des greffons et de leur efficacité.
Dans le contexte de mobilisation des greffons de cellules souches et de progéniteurs hématopoïétiques (CSH et PH), la qualité du greffon repose sur son contenu en cellules CD34+. Ce marqueur étant ...partagé par les CSH et PH, il ne rend donc pas compte du contenu réel en CSH assurant la greffe à long terme. Nous étudions ici les profiles phénotypique et métabolique, la capacité de greffe et la capacité de différenciation hématopoïétiques des CSH des greffons de patients bon mobilisateurs (bras G-CSF seul) et de patients mauvais mobilisateurs (bras G-CSF/Plerixafor). Les CSH sont ciblées par approche directe « Side Population (SP) » au sein de la fraction CD34+ de greffons mobilisés avec G-SCF ou G-CSF/Plerixafor. Les résultats montrent que l’association du Plerixafor au G-CSF chez les patients mauvais mobilisateurs permet de restaurer une quantité de cellules SP ayant un phénotype immature (CD38low, CD133+, SP) identique à celle des patients bons mobilisateurs. Les profiles métaboliques (masse et activité mitochondriales, incorporation de glucose, production de radicaux libres) et les capacités de différenciation in vitro (érythroïde, myéloïde et lymphoïde B) sont identiques quel que soit le type de mobilisation. En revanche, les cellules SP des greffons G-CSF/Plerixafor présentent une capacité de greffe inférieure à celles des greffons G-CSF seul. En conclusion, bien que les cellules CD34+ obtenues avec G-CSF/Plerixafor partagent des caractéristiques identiques à celles mobilisées avec G-CSF seul, elles semblent contenir moins de vraies CSH, questionnant ainsi la relevance du CD34 comme seul marqueur de la qualité des greffons hématopoïétiques.
Botrytis cinerea is the causing agent of the grey mold disease in more than 200 crop species. While signaling pathways leading to the basal resistance against this fungus are well described, the role ...of the import of sugars into host cells remains to be investigated. In Arabidopsis thaliana, apoplastic hexose retrieval is mediated by the activity of sugar transport proteins (STPs). Expression analysis of the 14 STP genes revealed that only STP13 was induced in leaves challenged with B. cinerea. STP13-modified plants were produced and assayed for their resistance to B. cinerea and glucose transport activity. We report that STP13-deficient plants exhibited an enhanced susceptibility and a reduced rate of glucose uptake. Conversely, plants with a high constitutive level of STP13 protein displayed an improved capacity to absorb glucose and an enhanced resistance phenotype. The correlation between STP13 transcripts, protein accumulation, glucose uptake rate and resistance level indicates that STP13 contributes to the basal resistance to B. cinerea by limiting symptom development and points out the importance of the host intracellular sugar uptake in this process. We postulate that STP13 would participate in the active resorption of hexoses to support the increased energy demand to trigger plant defense reactions and to deprive the fungus by changing sugar fluxes toward host cells.
Cell wall invertases (CWIN) cleave sucrose into glucose and fructose in the apoplast. CWINs are key regulators of carbon partitioning and source/sink relationships during growth, development and ...under biotic stresses. In this report, we monitored the expression/activity of
cell wall invertases in organs behaving as source, sink, or subjected to a source/sink transition after infection with the necrotrophic fungus
. We showed that organs with different source/sink status displayed differential CWIN activities, depending on carbohydrate needs or availabilities in the surrounding environment, through a transcriptional and posttranslational regulation. Loss-of-function mutation of the
cell wall invertase 1 gene,
, showed that the corresponding protein was the main contributor to the apoplastic sucrose cleaving activity in both leaves and roots. The CWIN-deficient mutant
exhibited a reduced capacity to actively take up external sucrose in roots, indicating that this process is mainly dependent on the sucrolytic activity of
. Using T-DNA and CRISPR/Cas9 mutants impaired in hexose transport, we demonstrated that external sucrose is actively absorbed in the form of hexoses by a sugar/H
symport system involving the coordinated activity of AtCWIN1 with several Sugar Transporter Proteins (STP) of the plasma membrane, i.e., STP1 and STP13. Part of external sucrose was imported without apoplastic cleavage into
seedling roots, highlighting an alternative
-independent pathway for the assimilation of external sucrose. Accordingly, we showed that several genes encoding sucrose transporters of the plasma membrane were expressed. We also detected transcript accumulation of vacuolar invertase (VIN)-encoding genes and high VIN activities. Upon infection,
was responsible for all the
-induced apoplastic invertase activity. We detected a transcriptional activation of several
and
genes accompanied with an enhanced vacuolar invertase activity, suggesting that the
-independent pathway is efficient upon infection. In absence of
, we postulate that intracellular sucrose hydrolysis is sufficient to provide intracellular hexoses to maintain sugar homeostasis in host cells and to fuel plant defenses. Finally, we demonstrated that
possesses its own functional sucrolytic machinery and hexose uptake system, and does not rely on the host apoplastic invertases.
Photoassimilates play crucial roles during plant-pathogen interactions, as colonizing pathogens rely on the supply of sugars from hosts. The competition for sugar acquisition at the plant-pathogen ...interface involves different strategies from both partners which are critical for the outcome of the interaction. Here, we dissect individual mechanisms of sugar uptake during the interaction of Arabidopsis thaliana with the necrotrophic fungus Botrytis cinerea using millicell culture insert, that enables molecular communication without physical contact. We demonstrate that B. cinerea is able to actively absorb glucose and fructose with equal capacities. Challenged Arabidopsis cells compete for extracellular monosaccharides through transcriptional reprogramming of host sugar transporter genes and activation of a complex sugar uptake system which displays differential specificity and affinity for hexoses. We provide evidence that the molecular dialogue between Arabidopsis cells and B. cinerea triggers major changes in host metabolism, including apoplastic sucrose degradation and consumption of carbohydrates and oxygen, suggesting an enhanced activity of the glycolysis and the cellular respiration. We conclude that beside a role in sugar deprivation of the pathogen by competing for sugar availability in the apoplast, the enhanced uptake of hexoses also contributes to sustain the increased activity of respiratory metabolism to fuel plant defences.
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