Publications by authors named "Metchette K"

Intratumoral (IT) STING activation results in tumor regression in preclinical models, yet factors dictating the balance between innate and adaptive anti-tumor immunity are unclear. Here, clinical candidate STING agonist ADU-S100 (S100) is used in an IT dosing regimen optimized for adaptive immunity to uncover requirements for a T cell-driven response compatible with checkpoint inhibitors (CPIs). In contrast to high-dose tumor ablative regimens that result in systemic S100 distribution, low-dose immunogenic regimens induce local activation of tumor-specific CD8 effector T cells that are responsible for durable anti-tumor immunity and can be enhanced with CPIs.

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There are a limited number of adjuvants that elicit effective cell-based immunity required for protection against intracellular bacterial pathogens. Here, we report that STING-activating cyclic dinucleotides (CDNs) formulated in a protein subunit vaccine elicit long-lasting protective immunity to Mycobacterium tuberculosis in the mouse model. Subcutaneous administration of this vaccine provides equivalent protection to that of the live attenuated vaccine strain Bacille Calmette-Guérin (BCG).

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Article Synopsis
  • Spontaneous T cell priming against tumors relies on interferon-beta (IFN-β) produced by dendritic cells within the tumor environment.
  • Researchers hypothesized that activating the STING pathway directly in tumors using specific agonists could lead to effective anti-tumor therapies.
  • Experiments with the STING agonist DMXAA showed strong tumor regression in mice, leading to the development of synthetic cyclic dinucleotide (CDN) compounds that work on both human and mouse STING, showing promise for future cancer treatments.
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A photochemical treatment (PCT) process using a novel psoralen and long wavelength ultraviolet light (UVA, 320-400 nm) has been developed to inactivate bacteria and viruses in platelet concentrates. This study evaluated the efficacy of PCT for inactivation of leukocytes that contaminate platelet preparations. Three psoralens, 8-methoxypsoralen (8-MOP), 4'-aminomethyl 4,5', 8-trimethylpsoralen (AMT), and the novel psoralen S-59, were compared using the following four independent but complementary biological and molecular assays.

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Background: A photochemical treatment process has been developed for the inactivation of viruses and bacteria in platelet concentrates. This process is based on the photochemical reaction of a novel psoralen, S-59, with nucleic acids upon illumination with long-wavelength ultraviolet light (UVA, 320-400 nm).

Study Design And Methods: High levels of pathogens were added to single-donor platelet concentrates containing 3 to 5 x 10(11) platelets in 300 mL of 35-percent autologous plasma and 65-percent platelet additive solution.

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We describe a photochemical procedure for the sterilization of polynucleotides that are created by the Polymerase Chain Reaction (PCR). The procedure is based upon the blockage of Taq DNA polymerase when it encounters a photochemically modified base in a polynucleotide strand. We have discovered reagents that can be added to a PCR reaction mixture prior to amplification and tolerate the thermal cycles of PCR, are photoactivated after amplification, and damage a PCR strand in a manner that, should the damaged strand be carried over into a new reaction vessel, prevent it from functioning as a template for the PCR.

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We have developed an effective post-PCR sterilization process and have applied the procedure to a diagnostic assay for HIV-1. The method, which is based on isopsoralen photochemistry, satisfies both the inactivation and hybridization requirements of a practical sterilization process. The key feature of the technique is the use of isopsoralen compounds which form covalent photochemical adducts with DNA.

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