RESUMEN
Severe coronavirus disease 2019 (COVID-19) is associated with an overactive inflammatory response mediated by macrophages. Here, we analyzed the phenotype and function of neutrophils in patients with COVID-19. We found that neutrophils from patients with severe COVID-19 express high levels of CD11b and CD66b, spontaneously produce CXCL8 and CCL2, and show a strong association with platelets. Production of CXCL8 correlated with plasma concentrations of lactate dehydrogenase and D-dimer. Whole blood assays revealed that neutrophils from patients with severe COVID-19 show a clear association with immunoglobulin G (IgG) immune complexes. Moreover, we found that sera from patients with severe disease contain high levels of immune complexes and activate neutrophils through a mechanism partially dependent on FcγRII (CD32). Interestingly, when integrated in immune complexes, anti-severe acute respiratory syndrome coronavirus 2 IgG antibodies from patients with severe COVID-19 displayed a higher proinflammatory profile compared with antibodies from patients with mild disease. Our study suggests that IgG immune complexes might promote the acquisition of an inflammatory signature by neutrophils, worsening the course of COVID-19.
Asunto(s)
Anticuerpos Antivirales/inmunología , Complejo Antígeno-Anticuerpo/inmunología , COVID-19/inmunología , Inmunoglobulina G/inmunología , Activación Neutrófila/inmunología , Adulto , Anciano , Anticuerpos Antivirales/sangre , Complejo Antígeno-Anticuerpo/sangre , Antígenos CD/inmunología , Antígeno CD11b/inmunología , Moléculas de Adhesión Celular/inmunología , Femenino , Proteínas Ligadas a GPI/inmunología , Humanos , Inmunoglobulina G/sangre , Interleucina-8/inmunología , Masculino , Persona de Mediana Edad , Neutrófilos/inmunología , Receptores de IgG/inmunología , SARS-CoV-2/inmunología , Adulto JovenRESUMEN
A deficient interferon (IFN) response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been implicated as a determinant of severe coronavirus disease 2019 (COVID-19). To identify the molecular effectors that govern IFN control of SARS-CoV-2 infection, we conducted a large-scale gain-of-function analysis that evaluated the impact of human IFN-stimulated genes (ISGs) on viral replication. A limited subset of ISGs were found to control viral infection, including endosomal factors inhibiting viral entry, RNA binding proteins suppressing viral RNA synthesis, and a highly enriched cluster of endoplasmic reticulum (ER)/Golgi-resident ISGs inhibiting viral assembly/egress. These included broad-acting antiviral ISGs and eight ISGs that specifically inhibited SARS-CoV-2 and SARS-CoV-1 replication. Among the broad-acting ISGs was BST2/tetherin, which impeded viral release and is antagonized by SARS-CoV-2 Orf7a protein. Overall, these data illuminate a set of ISGs that underlie innate immune control of SARS-CoV-2/SARS-CoV-1 infection, which will facilitate the understanding of host determinants that impact disease severity and offer potential therapeutic strategies for COVID-19.
Asunto(s)
Antígenos CD/genética , Interacciones Huésped-Patógeno/genética , Factores Reguladores del Interferón/genética , Interferón Tipo I/genética , SARS-CoV-2/genética , Proteínas Virales/genética , Animales , Antígenos CD/química , Antígenos CD/inmunología , Sitios de Unión , Línea Celular Tumoral , Chlorocebus aethiops , Retículo Endoplásmico/genética , Retículo Endoplásmico/inmunología , Retículo Endoplásmico/virología , Proteínas Ligadas a GPI/química , Proteínas Ligadas a GPI/genética , Proteínas Ligadas a GPI/inmunología , Regulación de la Expresión Génica , Aparato de Golgi/genética , Aparato de Golgi/inmunología , Aparato de Golgi/virología , Células HEK293 , Interacciones Huésped-Patógeno/inmunología , Humanos , Inmunidad Innata , Factores Reguladores del Interferón/clasificación , Factores Reguladores del Interferón/inmunología , Interferón Tipo I/inmunología , Simulación del Acoplamiento Molecular , Unión Proteica , Conformación Proteica en Hélice alfa , Conformación Proteica en Lámina beta , Dominios y Motivos de Interacción de Proteínas , SARS-CoV-2/inmunología , Transducción de Señal , Células Vero , Proteínas Virales/química , Proteínas Virales/inmunología , Internalización del Virus , Liberación del Virus/genética , Liberación del Virus/inmunología , Replicación Viral/genética , Replicación Viral/inmunologíaRESUMEN
In coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the relationship between disease severity and the host immune response is not fully understood. Here we performed single-cell RNA sequencing in peripheral blood samples of 5 healthy donors and 13 patients with COVID-19, including moderate, severe and convalescent cases. Through determining the transcriptional profiles of immune cells, coupled with assembled T cell receptor and B cell receptor sequences, we analyzed the functional properties of immune cells. Most cell types in patients with COVID-19 showed a strong interferon-α response and an overall acute inflammatory response. Moreover, intensive expansion of highly cytotoxic effector T cell subsets, such as CD4+ effector-GNLY (granulysin), CD8+ effector-GNLY and NKT CD160, was associated with convalescence in moderate patients. In severe patients, the immune landscape featured a deranged interferon response, profound immune exhaustion with skewed T cell receptor repertoire and broad T cell expansion. These findings illustrate the dynamic nature of immune responses during disease progression.
Asunto(s)
Antígenos CD/metabolismo , Antígenos de Diferenciación de Linfocitos T/metabolismo , Betacoronavirus/inmunología , Infecciones por Coronavirus/inmunología , Interferón Tipo I/metabolismo , Neumonía Viral/inmunología , Receptores Inmunológicos/metabolismo , Adolescente , Adulto , Anciano , Antígenos CD/genética , Antígenos CD/inmunología , Antígenos de Diferenciación de Linfocitos T/genética , Antígenos de Diferenciación de Linfocitos T/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , COVID-19 , Estudios de Cohortes , Infecciones por Coronavirus/sangre , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/virología , Femenino , Proteínas Ligadas a GPI/genética , Proteínas Ligadas a GPI/inmunología , Proteínas Ligadas a GPI/metabolismo , Humanos , Interferón Tipo I/genética , Interferón Tipo I/inmunología , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/sangre , Neumonía Viral/diagnóstico , Neumonía Viral/virología , RNA-Seq , Receptores Inmunológicos/genética , Receptores Inmunológicos/inmunología , SARS-CoV-2 , Índice de Severidad de la Enfermedad , Análisis de la Célula IndividualRESUMEN
Zoonotic coronaviruses (CoVs) are substantial threats to global health, as exemplified by the emergence of two severe acute respiratory syndrome CoVs (SARS-CoV and SARS-CoV-2) and Middle East respiratory syndrome CoV (MERS-CoV) within two decades1-3. Host immune responses to CoVs are complex and regulated in part through antiviral interferons. However, interferon-stimulated gene products that inhibit CoVs are not well characterized4. Here, we show that lymphocyte antigen 6 complex, locus E (LY6E) potently restricts infection by multiple CoVs, including SARS-CoV, SARS-CoV-2 and MERS-CoV. Mechanistic studies revealed that LY6E inhibits CoV entry into cells by interfering with spike protein-mediated membrane fusion. Importantly, mice lacking Ly6e in immune cells were highly susceptible to a murine CoV-mouse hepatitis virus. Exacerbated viral pathogenesis in Ly6e knockout mice was accompanied by loss of hepatic immune cells, higher splenic viral burden and reduction in global antiviral gene pathways. Accordingly, we found that constitutive Ly6e directly protects primary B cells from murine CoV infection. Our results show that LY6E is a critical antiviral immune effector that controls CoV infection and pathogenesis. These findings advance our understanding of immune-mediated control of CoV in vitro and in vivo-knowledge that could help inform strategies to combat infection by emerging CoVs.