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
Naturally occurring T cells that recognize microbial peptides via HLA-E, a nonpolymorphic HLA class Ib molecule, could provide the foundation for new universal immunotherapeutics. However, confidence in the biological relevance of putative ligands is crucial, given that the mechanisms by which pathogen-derived peptides can access the HLA-E presentation pathway are poorly understood. We systematically interrogated the HIV proteome using immunopeptidomic and bioinformatic approaches, coupled with biochemical and cellular assays. No HIV HLA-E peptides were identified by tandem mass spectrometry analysis of HIV-infected cells. In addition, all bioinformatically predicted HIV peptide ligands (>80) were characterized by poor complex stability. Furthermore, infected cell elimination assays using an affinity-enhanced T cell receptor bispecific targeted to a previously reported HIV Gag HLA-E epitope demonstrated inconsistent presentation of the peptide, despite normal HLA-E expression on HIV-infected cells. This work highlights the instability of the HIV HLA-E peptidome as a major challenge for drug development.
Asunto(s)
Infecciones por VIH , Antígenos HLA-E , Humanos , Antígenos de Histocompatibilidad Clase I/genética , Antígenos de Histocompatibilidad Clase I/metabolismo , Epítopos , Infecciones por VIH/terapia , Péptidos/metabolismoRESUMEN
Fibroblasts are the major producers of the extracellular matrix and regulate its organization. Aberrant signaling in diseases such as fibrosis and cancer can impact the deposition of the matrix proteins, which can in turn act as an adhesion scaffold and signaling reservoir promoting disease progression. To study the composition and organization of the extracellular matrix as well as its interactions with (tumor) cells, this protocol describes the generation and analysis of 3D fibroblast-derived matrices and the investigation of (tumor) cells seeded onto the 3D scaffolds by immunofluorescent imaging and cell adhesion, colony formation, migration, and invasion/transmigration assays.