Project description:Inborn errors of human IFN-γ immunity underlie mycobacterial diseases, whereas inborn errors of IFN-/ immunity underlie viral diseases. Both types of IFNs induce the transcription factor IRF1. We describe two unrelated children with inherited complete IRF1 deficiency and early-onset, multiple, life-threatening diseases caused by weakly virulent mycobacteria. These children have no history of severe viral disease, despite exposure to many viruses, including SARS-CoV-2, which is life-threatening in individuals with impaired IFN-/ immunity. The IRF1-dependent cellular responses to IFN-γ are, both quantitatively and qualitatively, much greater than those to IFN-/ in vitro. Monocyte- and iPSC-derived macrophages from the two patients show no upregulation of at least 20% of the target genes normally induced by IFN-γ. By contrast, cell-intrinsic IFN-/ immunity to diverse viruses, including SARS-CoV-2, is intact. Human IRF1 is, thus, largely redundant for antiviral IFN-/ immunity. By contrast, human IRF1 is essential for IFN-γ immunity to mycobacteria in myeloid cells.
Project description:Inborn errors of human IFN-γ-dependent macrophagic immunity underlie mycobacterial diseases, whereas inborn errors of IFN-α/β-dependent intrinsic immunity underlie viral diseases. Both types of IFNs induce the transcription factor IRF1. We describe unrelated children with inherited complete IRF1 deficiency and early-onset, multiple, life-threatening diseases caused by weakly virulent mycobacteria and related intramacrophagic pathogens. These children have no history of severe viral disease, despite exposure to many viruses, including SARS-CoV-2, which is life-threatening in individuals with impaired IFN-α/β immunity. In leukocytes or fibroblasts stimulated in vitro, IRF1-dependent responses to IFN-γ are, both quantitatively and qualitatively, much stronger than those to IFN-α/β. Moreover, IRF1-deficient mononuclear phagocytes do not control mycobacteria and related pathogens normally when stimulated with IFN-γ. By contrast, IFN-α/β-dependent intrinsic immunity to nine viruses, including SARS-CoV-2, is almost normal in IRF1-deficient fibroblasts. Human IRF1 is essential for IFN-γ-dependent macrophagic immunity to mycobacteria, but largely redundant for IFN-α/β-dependent antiviral immunity.
Project description:Inborn errors of human IFN-γ immunity underlie mycobacterial diseases, while inborn errors of IFN-a/b immunity underlie viral diseases. Both types of IFNs induce the transcription factor IRF1. We describe two unrelated children with inherited complete IRF1 deficiency and early-onset, multiple, life-threatening diseases caused by weakly virulent mycobacteria. They have no history of severe viral disease, despite exposure to many viruses, including SARS-CoV-2 that is life-threatening in individuals with deficient IFN-a/b. There is a much greater IRF1-dependent response to IFN-γ than IFN-a/b in vitro, both quantitatively and qualitatively. Monocyte-derived macrophages and iPSC-derived macrophages of both patients do not upregulate at least 40% of target genes normally induced by IFN-γ. In contrast, cell-intrinsic IFN-a/b immunity to a wide range of viruses, including HIV and SARS-CoV-2, is maintained. Human IRF1 is thus largely redundant for antiviral IFN-a/b immunity across cell types. By contrast, human IRF1 is essential for IFN-γ immunity to mycobacteria in mononuclear myeloid cells.
Project description:Inborn errors of human IFN-γ immunity underlie mycobacterial diseases, while inborn errors of IFN-a/b immunity underlie viral diseases. Both types of IFNs induce the transcription factor IRF1. We describe two unrelated children with inherited complete IRF1 deficiency and early-onset, multiple, life-threatening diseases caused by weakly virulent mycobacteria. They have no history of severe viral disease, despite exposure to many viruses, including SARS-CoV-2 that is life-threatening in individuals with deficient IFN-a/b. There is a much greater IRF1-dependent response to IFN-γ than IFN-a/b in vitro, both quantitatively and qualitatively. Monocyte-derived macrophages and iPSC-derived macrophages of both patients do not upregulate at least 40% of target genes normally induced by IFN-γ. In contrast, cell-intrinsic IFN-a/b immunity to a wide range of viruses, including HIV and SARS-CoV-2, is maintained. Human IRF1 is thus largely redundant for antiviral IFN-a/b immunity across cell types. By contrast, human IRF1 is essential for IFN-γ immunity to mycobacteria in mononuclear myeloid cells.
Project description:Inborn errors of human IFN-γ immunity underlie mycobacterial diseases, whereas inborn errors of IFN-a/b immunity underlie viral diseases. Both types of IFNs induce the transcription factor IRF1. We describe two unrelated children with inherited complete IRF1 deficiency and early-onset, multiple, life-threatening diseases caused by weakly virulent mycobacteria. These children have no history of severe viral disease, despite exposure to many viruses, including SARS-CoV-2, which is life-threatening in individuals with impaired IFN-a/b immunity. The IRF1-dependent cellular responses to IFN-γ are, both quantitatively and qualitatively, much greater than those to IFN-a/b in vitro. Monocyte- and iPSC-derived macrophages from the two patients show no upregulation of at least 20% of the target genes normally induced by IFN-γ. By contrast, cell-intrinsic IFN-a/b immunity to diverse viruses, including SARS-CoV-2, is intact. Human IRF1 is, thus, largely redundant for antiviral IFN-a/b immunity. By contrast, human IRF1 is essential for IFN-γ immunity to mycobacteria in myeloid cells.