| 1. |
- Donia, Marco, et al.
(författare)
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Acquired immune resistance follows complete tumor regression without loss of target antigens or IFNγ signaling
- 2017
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Ingår i: Cancer Research. - 0008-5472. ; 77:17, s. 4562-4566
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Tidskriftsartikel (refereegranskat)abstract
- Cancer immunotherapy can result in durable tumor regressions in some patients. However, patients who initially respond often experience tumor progression. Here, we report mechanistic evidence of tumoral immune escape in an exemplary clinical case: a patient with metastatic melanoma who developed disease recurrence following an initial, unequivocal radiologic complete regression after T-cell–based immunotherapy. Functional cytotoxic T-cell responses, including responses to one mutant neoantigen, were amplified effectively with therapy and generated durable immunologic memory. However, these immune responses, including apparently effective surveillance of the tumor mutanome, did not prevent recurrence. Alterations of the MHC class I antigen-processing and presentation machinery (APM) in resistant cancer cells, but not antigen loss or impaired IFNγ signaling, led to impaired recognition by tumor-specific CD8þ T cells. Our results suggest that future immunotherapy combinations should take into account targeting cancer cells with intact and impaired MHC class I–related APM. Loss of target antigens or impaired IFNγ signaling does not appear to be mandatory for tumor relapse after a complete radiologic regression. Personalized studies to uncover mechanisms leading to disease recurrence within each individual patient are warranted.
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| 2. |
- Hakon, Jakob, et al.
(författare)
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Inhibiting metabotropic glutamate receptor 5 after stroke restores brain function and connectivity
- 2024
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Ingår i: Brain : a journal of neurology. - 1460-2156. ; 147:1, s. 186-200
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Tidskriftsartikel (refereegranskat)abstract
- Stroke results in local neural disconnection and brain-wide neuronal network dysfunction leading to neurological deficits. Beyond the hyper-acute phase of ischemic stroke, there is no clinically-approved pharmacological treatment that alleviates sensorimotor impairments. Functional recovery after stroke involves the formation of new or alternative neuronal circuits including existing neural connections. The type-5 metabotropic glutamate receptor (mGluR5) has been shown to modulate brain plasticity and function, and is a therapeutic target in neurological diseases outside of stroke. We investigated whether mGluR5 influences functional recovery and network reorganization rodent models of focal ischemia. Using multiple behavioral tests we observed that treatment with negative allosteric modulators (NAMs) of mGluR5 (MTEP, fenobam, and AFQ056) for 12 days, starting 2 or 10 days after stroke, restored lost sensorimotor functions, without diminishing infarct size. Recovery was evident within hours after initiation of treatment and progressed over the subsequent 12 days. Recovery was prevented by activation of mGluR5 with the positive allosteric modulator VU0360172, and accelerated in mGluR5 KO mice compared to wild-type mice. After stroke, multisensory stimulation by enriched environments (EE) enhanced recovery, a result prevented by VU0360172, implying a role of mGluR5 in EE-mediated recovery. Additionally, MTEP treatment in conjunction with EE housing provided an additive recovery enhancement compared to either MTEP or EE alone. Using optical intrinsic signal imaging, we observed brain-wide disruptions in resting-state functional connectivity after stroke that were prevented by mGluR5 inhibition in distinct areas of contralesional sensorimotor and bilateral visual cortices. The levels of mGluR5 protein in mice and in tissue samples of stroke patients were unchanged after stroke. We conclude that neuronal circuitry subserving sensorimotor function after stroke is depressed by a mGluR5-dependent maladaptive plasticity mechanism that can be restored by mGluR5 inhibition. Post-acute stroke treatment with mGluR5 NAMs combined with rehabilitative training may represent a novel post-acute stroke therapy.
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| 3. |
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| 4. |
- Sebastianutto, Irene, et al.
(författare)
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D1-mGlu5 heteromers mediate noncanonical dopamine signaling in Parkinson’s disease
- 2020
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Ingår i: Journal of Clinical Investigation. - 0021-9738. ; 130:3, s. 1168-1184
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Tidskriftsartikel (refereegranskat)abstract
- Dopamine receptor D1 modulates glutamatergic transmission in cortico-basal ganglia circuits and represents a major target of L-DOPA therapy in Parkinson’s disease. Here we show that D1 and metabotropic glutamate type 5 (mGlu5) receptors can form previously unknown heteromeric entities with distinctive functional properties. Interacting with Gq proteins, cell-surface D1-mGlu5 heteromers exacerbated PLC signaling and intracellular calcium release in response to either glutamate or dopamine. In rodent models of Parkinson’s disease, D1-mGlu5 nanocomplexes were strongly upregulated in the dopamine-denervated striatum, resulting in a synergistic activation of PLC signaling by D1 and mGlu5 receptor agonists. In turn, D1-mGlu5–dependent PLC signaling was causally linked with excessive activation of extracellular signal–regulated kinases in striatal neurons, leading to dyskinesia in animals treated with L-DOPA or D1 receptor agonists. The discovery of D1-mGlu5 functional heteromers mediating maladaptive molecular and motor responses in the dopamine-denervated striatum may prompt the development of new therapeutic principles for Parkinson’s disease.
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