Discovery and characterization of allosteric CD45 inhibitors
Notice bibliographique
Résumé
CD45 phosphatase is expressed ubiquitously on cells of lymphoid origin, and has long been considered a drug target for immunosuppression. CD45 is a key component of the signaling pathway in immune cells, regulating activation and development of these cells. Drug intervention could suppress growth and provide a therapeutic avenue for treatment of transplant rejection, auto-immune diseases such as rheumatoid arthritis, and various cancers of the immune system. The intracellular, catalytic portion of CD45 is comprised of the D1 and D2 domains. The active site is located in the D1 domain, and the D2 domain is catalytically inactive. We decided to target the inter-domain region between D1 and D2 for the development of a small molecule allosteric inhibitor. The linker region between CD45 D1 and D2 was modeled in silico, and NCI database was screened for compounds that dock in this region. Hits were tested in vitro and we detected two CD45 inhibitors, one of which was demonstrated to be highly selective for CD45 in tyrosine phosphatase counter-assays. Analogs were generated which increased in vitro potency, and cell membrane permeability. The most active inhibitor, 211, was pursued further. The kinetics of CD45 inhibition by 211 indicated a non-competitive and irreversible mechanism of action, as well as some degree of substrate specificity. Site-directed mutations in CD45 enzyme at the predicted 211 binding sites revealed a loss of inhibition by 211 in the mutant CD45, consistent with the in silico prediction of allosteric inhibition. Circular dichroism studies indicated a conformational change in CD45 enzyme, in the presence of 211. We first validated that CD45 was the target of 211 in cells, by evidence of a change in the phosphorylation of its in vivo substrate Lck in Jurkat cells. As a control, the phosphorylation status of Lck was not affected in J45.01 (CD45-negative) cells with 211 treatment. 211 was shown to suppress the activation of T cell receptor signaling in primary T cells. In vivo, 211 inhibits the antigen-induced immune response in the mouse footpad.CD45 inhibitor 211 was assayed for its anti-cancer properties in the EL4 mouse thymoma cell line. 211 inflicted dose-dependent toxicity on these cells via cell cycle rest and apoptosis. EL4 cells injected into mice were delayed in developing a solid tumor when mice were treated with 211, and metastasis to the lymph nodes was reduced in these animals. Our work has shown the therapeutic potential of targeting CD45 by revealing a novel allosteric binding site for a CD45 inhibitor, and this approach may be useful for targeting other two-domain tyrosine phosphatases.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| 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 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,001 |
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 source (Gemma direct ou Codex distillé), 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 ».