RESUMEN
Peptides presented by HLA-E, a molecule with very limited polymorphism, represent attractive targets for T cell receptor (TCR)-based immunotherapies to circumvent the limitations imposed by the high polymorphism of classical HLA genes in the human population. Here, we describe a TCR-based bispecific molecule that potently and selectively binds HLA-E in complex with a peptide encoded by the inhA gene of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis in humans. We reveal the biophysical and structural bases underpinning the potency and specificity of this molecule and demonstrate its ability to redirect polyclonal T cells to target HLA-E-expressing cells transduced with mycobacterial inhA as well as primary cells infected with virulent Mtb. Additionally, we demonstrate elimination of Mtb-infected cells and reduction of intracellular Mtb growth. Our study suggests an approach to enhance host T cell immunity against Mtb and provides proof of principle for an innovative TCR-based therapeutic strategy overcoming HLA polymorphism and therefore applicable to a broader patient population.
Asunto(s)
Antígenos de Histocompatibilidad Clase I , Mycobacterium tuberculosis , Receptores de Antígenos de Linfocitos T , Linfocitos T , Mycobacterium tuberculosis/inmunología , Humanos , Receptores de Antígenos de Linfocitos T/inmunología , Receptores de Antígenos de Linfocitos T/metabolismo , Antígenos de Histocompatibilidad Clase I/inmunología , Antígenos de Histocompatibilidad Clase I/metabolismo , Linfocitos T/inmunología , Antígenos HLA-E , Proteínas Bacterianas/inmunología , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Tuberculosis/inmunologíaRESUMEN
Antifungal protein (AFP) from Aspergillus giganteus was assayed for toxicity against the Fusarium oxysporum wild-type strain and mutants in genes involved in cell signaling (DeltapacC, pacCc Deltafmk1) or cell-wall biogenesis (DeltachsV, Deltachs7, Deltagas1). The mutants were classified into two groups according to their sensitivity to AFP: DeltapacC, Deltagas1 and Deltachs7, which were significantly more resistant to AFP than the wild-type, and pacCC, Deltafmk1 and DeltachsV, which were more sensitive. Western blot analysis revealed increased binding of AFP to the three resistant mutants, DeltapacC, Deltagas1 and Deltachs7, but also to DeltachsV, indicating that differential binding may not be a key determinant for sensitivity. Addition of Ca2+ or K+ dramatically reduced antifungal activity and binding of AFP, suggesting that these cations compete for the same targets as AFP at the surface of the fungal cell (AU)
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