RESUMO
Although influenza viruses lead to severe illness in high-risk populations, host genetic factors associated with severe disease are largely unknown. As the HLA-A*68:01 allele can be linked to severe pandemic 2009-H1N1 disease, we investigate a potential impairment of HLA-A*68:01-restricted CD8+ T cells to mount robust responses. We elucidate the HLA-A*68:01+CD8+ T cell response directed toward an extended influenza-derived nucleoprotein (NP) peptide and show that only ~35% individuals have immunodominant A68/NP145+CD8+ T cell responses. Dissecting A68/NP145+CD8+ T cells in low vs. medium/high responders reveals that high responding donors have A68/NP145+CD8+ memory T cells with clonally expanded TCRαßs, while low-responders display A68/NP145+CD8+ T cells with predominantly naïve phenotypes and non-expanded TCRαßs. Single-cell index sorting and TCRαß analyses link expansion of A68/NP145+CD8+ T cells to their memory potential. Our study demonstrates the immunodominance potential of influenza-specific CD8+ T cells presented by a risk HLA-A*68:01 molecule and advocates for priming CD8+ T cell compartments in HLA-A*68:01-expressing individuals for establishment of pre-existing protective memory T cell pools.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Antígenos HLA-A/imunologia , Antígenos HLA-A/metabolismo , Vírus da Influenza A/imunologia , Influenza Humana/imunologia , Apresentação de Antígeno , Antígenos Virais/química , Linhagem Celular , Proteção Cruzada , Reações Cruzadas/imunologia , Epitopos de Linfócito T/imunologia , Antígenos HLA-A/química , Antígenos HLA-A/genética , Humanos , Memória Imunológica/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Modelos Moleculares , Nucleoproteínas/química , Orthomyxoviridae/genética , Orthomyxoviridae/imunologia , Fragmentos de Peptídeos/química , Fenótipo , Conformação Proteica , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Proteínas do Core Viral/genéticaRESUMO
Breakthrough invasive fungal infections among patients with hematologic malignancies receiving voriconazole are being reported with increasing frequency, with zygomycete infections predominating. We report a case of disseminated Scedosporium prolificans infection in a patient receiving voriconazole prophylaxis. Despite poor in vitro activity of voriconazole for this organism, synergy studies using the checkerboard method demonstrated synergy with the combination of voriconazole and terbinafine. This regimen, in conjunction with central venous line removal and intravitreal voriconazole, contributed to the recovery of the patient. S. prolificans is a life-threatening mold that should be considered in patients with breakthrough invasive fungal infections while on voriconazole prophylaxis.