Control of Cell Death Levels Using Th9402-Based PDT Treatment on Fresh PBMC, and Potential Application to Patients with cGvHD.
Notice bibliographique
Résumé
Abstract Recently, extracorporeal photopheresis (ECP) has shown interesting clinical activity for the treatment of drug-refractory chronic graft-vs-host disease (cGvHD), inducing Th1/Th2 immunomodulation to restore immune tolerance. Several studies indicate that target cell apoptosis may have a role in the control of cGVHD, and increasing apoptotic levels may favor immune modulation. We have developed an approach to eliminate immunoreactive cells using the Theralux™ photodynamic cell therapy (PDT) system based on the use of the rhodamine-derivative TH9402 illuminated ex vivo with a visible light source (l=514nm). The capacity of TH9402 PDT to induce increasing levels of T cell apoptosis has not been investigated. The induction of apoptotic cell death was studied using peripheral blood mononuclear cells (PBMCs) isolated from healthy volunteers (HV) and cGvHD patients. We found a good correlation between PDT conditions and levels of cell death induced. In comparison to controls showing 8±4 percent (%) of apoptosis, as measured by TUNEL assay on cells harvested 3 days post-treatment, PBMC from HV subjected to PDT using 0.33, 0.66, or 1.32 micromolar of TH9402 showed 28±16%, 49±17%, and 78±11% of apoptosis, respectively. These studies have also shown that the intra- and inter-donor variability in TH9402 incorporation are very low (~5% and 10%, respectively). To ensure that these findings could also be applied to a clinical setting, PBMC from cGvHD patients were treated with 0.33 and 1.32 micromolar of TH9402 to trigger either low or high levels of apoptosis. PBMC from cGvHD patients showed a sensitivity similar to that of PBMC from HV, with 38±9% and 73±13% of apoptosis when treated with 0.33 and 1.32 micromolar TH9402, respectively. Data obtained from the analysis of various cell death parameters such as the loss of DΨm, AnV/PI staining, TUNEL assay and agarose DNA ladder on PBMC and human Jurkat T cells treated with escalating doses of TH9402 suggested strongly the higher sensitivity of proliferating cells to the treatment. Moreover, together with the use of the caspase-inhibitor ZVAD-fmk, these data suggested that upon irradiation, the photoactivation of TH9402 will trigger the formation of reactive oxygen species (ROS) and the release of proapoptotic factors from mitochondria triggering various cell death mechanisms, such as caspase-dependent apoptosis, caspase-independent apoptosis, or a mixture of apoptosis and necrosis. Finally, preliminary data showed that PDT-treated cells were able to induce in vitro the maturation of monocyte-derived dendritic cells. Based on these data, we are beginning a pilot clinical study evaluating two controlled PDT conditions inducing low and high levels of apoptosis in order to assess the efficacy and biological effect of TH9402-based ECP to treat cGVHD in humans.
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Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».