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1.
Clin Immunol ; 220: 108591, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32920210

RESUMO

Most severe cases with COVID-19, especially those with pulmonary failure, are not a consequence of viral burden and/or failure of the 'adaptive' immune response to subdue the pathogen by utilizing an adequate 'adaptive' immune defense. Rather it is a consequence of immunopathology, resulting from imbalanced innate immune response, which may not be linked to pathogen burden at all. In fact, it might be described as an autoinflammatory disease. The Kawasaki-like disease seen in children with SARS-CoV-2 exposure might be another example of similar mechanism.


Assuntos
Autoimunidade/genética , Betacoronavirus/patogenicidade , Infecções por Coronavirus/imunologia , Síndrome da Liberação de Citocina/imunologia , Interações Hospedeiro-Patógeno/imunologia , Pneumonia Viral/imunologia , Insuficiência Respiratória/imunologia , Doença Aguda , Imunidade Adaptativa , Betacoronavirus/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Linfócitos T CD8-Positivos/virologia , Infecções por Coronavirus/genética , Infecções por Coronavirus/fisiopatologia , Síndrome da Liberação de Citocina/genética , Síndrome da Liberação de Citocina/fisiopatologia , Interações Hospedeiro-Patógeno/genética , Humanos , Imunidade Inata , Ativação Linfocitária , Síndrome de Linfonodos Mucocutâneos/genética , Síndrome de Linfonodos Mucocutâneos/imunologia , Síndrome de Linfonodos Mucocutâneos/fisiopatologia , Pandemias , Pneumonia Viral/genética , Pneumonia Viral/fisiopatologia , Insuficiência Respiratória/genética , Insuficiência Respiratória/fisiopatologia , Índice de Gravidade de Doença
3.
J Int Med Res ; 48(9): 300060520958594, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32962495

RESUMO

OBJECTIVE: Coronavirus disease 2019 (COVID-19) shows a wide range of severity, ranging from an asymptomatic presentation to a severe illness requiring intensive care unit admission. Identification of a strategy to manage the severity of this disease will not only help to reduce its case fatality but also help to remove some of the burden from the already overwhelmed health care systems. While successful management of symptoms in general is important, identifying measures to modify the severity of the illness is a key factor in the fight against this pandemic. METHODS: This paper presents a short literature review to suggest a new treatment modality for COVID-19. RESULTS: COVID-19 is less severe and rarely fatal in children than in adults, which could be caused by greater fluctuations of plasma epinephrine in children. Our literature survey endorses this hypothesis according to both the epidemiological and immunological findings. CONCLUSION: Application of epinephrine pulses with a specific amplitude may be considered an intervention to minimize the severity of COVID-19.


Assuntos
Linfócitos T CD8-Positivos/efeitos dos fármacos , Ritmo Circadiano/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/epidemiologia , Epinefrina/uso terapêutico , Pandemias , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/epidemiologia , Adulto , Fatores Etários , Doenças Assintomáticas , Biomarcadores/sangue , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Criança , Ritmo Circadiano/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Esquema de Medicação , Epinefrina/sangue , Epinefrina/imunologia , Humanos , Imunidade Inata/efeitos dos fármacos , Modelos Imunológicos , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Prognóstico , Índice de Gravidade de Doença
4.
Nat Commun ; 11(1): 4454, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32901001

RESUMO

Chronic viral infections are often associated with impaired CD8+ T cell function, referred to as exhaustion. Although the molecular and cellular circuits involved in CD8+ T cell exhaustion are well defined, with sustained presence of antigen being one important parameter, how much T cell receptor (TCR) signaling is actually ongoing in vivo during established chronic infection is unclear. Here, we characterize the in vivo TCR signaling of virus-specific exhausted CD8+ T cells in a mouse model, leveraging TCR signaling reporter mice in combination with transcriptomics. In vivo signaling in exhausted cells is low, in contrast to their in vitro signaling potential, and despite antigen being abundantly present. Both checkpoint blockade and adoptive transfer of naïve target cells increase TCR signaling, demonstrating that engagement of co-inhibitory receptors curtails CD8+ T cell signaling and function in vivo.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Coriomeningite Linfocítica/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Transferência Adotiva , Animais , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Linfócitos T CD8-Positivos/virologia , Doença Crônica , Citotoxicidade Imunológica , Modelos Animais de Doenças , Regulação para Baixo , Tolerância Imunológica , Imunidade Celular , Técnicas In Vitro , Ativação Linfocitária , Coriomeningite Linfocítica/genética , Vírus da Coriomeningite Linfocítica/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/imunologia , Receptor de Morte Celular Programada 1/imunologia , RNA-Seq , Transdução de Sinais/imunologia
5.
APMIS ; 128(11): 593-602, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32870528

RESUMO

Induction of broad Th1 cellular immune responses and cytokines is crucial characteristics for vaccines against intracellular infections such as hepatitis C virus (HCV). Plants (especially oilseed tissues) and plant-immunomodulators (like oil bodies) offer cost-effective and scalable possibilities for the production of immunologically relevant and safe vaccine antigens and adjuvants, respectively. Herein, we provide data of the murine immunization by transgenic canola oilseed-derived HCV core protein (HCVcp) soluble extract (TSE) and Escherichia coli- derived rHCVcp in combination with Canola oil bodies (oil) compared to that of the Freund's (FA) adjuvant. Mice immunized by TSE+ oil developed both strong humeral (IgG) and Th1-biased cellular responses, manifested by high levels of IFN-γ and lower IgG1/IgG2a ratio and IL-4 secretion. Results of the intracellular cytokine staining indicated that TSE+ oil immunization in mice triggered both CD4+ and CD8+ T cells to release IFN-γ, while CD4+ cells were mostly triggered when FA was used. Analyses by qRT-PCR indicated that a combination of rHCVcp/TSE with oil body induced high levels of IL-10 cytokines compared to that of the FA adjuvant. These characteristics are important properties for the design of an HCV vaccine candidate and indicate the potential of Canola-derived antigen and oil bodies in addressing these concerns.


Assuntos
Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/prevenção & controle , Proteínas Recombinantes/administração & dosagem , Células Th1/efeitos dos fármacos , Proteínas do Core Viral/administração & dosagem , Vacinas contra Hepatite Viral/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/química , Animais , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Escherichia coli/genética , Escherichia coli/metabolismo , Feminino , Hepacivirus/imunologia , Hepacivirus/patogenicidade , Hepatite C Crônica/imunologia , Hepatite C Crônica/patologia , Hepatite C Crônica/virologia , Imunidade Celular/efeitos dos fármacos , Imunoglobulina G/biossíntese , Interferon gama/biossíntese , Interferon gama/imunologia , Interleucina-10/biossíntese , Interleucina-10/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Óleo de Brassica napus/administração & dosagem , Óleo de Brassica napus/química , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/imunologia , Células Th1/imunologia , Células Th1/virologia , Proteínas do Core Viral/biossíntese , Proteínas do Core Viral/imunologia , Vacinas contra Hepatite Viral/biossíntese
6.
Immunity ; 53(4): 724-732.e7, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-32783919

RESUMO

SARS-CoV-2 infection has emerged as a serious global pandemic. Because of the high transmissibility of the virus and the high rate of morbidity and mortality associated with COVID-19, developing effective and safe vaccines is a top research priority. Here, we provide a detailed evaluation of the immunogenicity of lipid nanoparticle-encapsulated, nucleoside-modified mRNA (mRNA-LNP) vaccines encoding the full-length SARS-CoV-2 spike protein or the spike receptor binding domain in mice. We demonstrate that a single dose of these vaccines induces strong type 1 CD4+ and CD8+ T cell responses, as well as long-lived plasma and memory B cell responses. Additionally, we detect robust and sustained neutralizing antibody responses and the antibodies elicited by nucleoside-modified mRNA vaccines do not show antibody-dependent enhancement of infection in vitro. Our findings suggest that the nucleoside-modified mRNA-LNP vaccine platform can induce robust immune responses and is a promising candidate to combat COVID-19.


Assuntos
Anticorpos Neutralizantes/biossíntese , Anticorpos Antivirais/biossíntese , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , RNA Mensageiro/imunologia , RNA Viral/imunologia , Vacinas Virais/administração & dosagem , Animais , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Linfócitos B/virologia , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/patologia , Modelos Animais de Doenças , Furina/genética , Furina/imunologia , Humanos , Imunidade Humoral/efeitos dos fármacos , Imunização/métodos , Imunogenicidade da Vacina , Memória Imunológica/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/administração & dosagem , Nanopartículas/química , Pneumonia Viral/imunologia , Pneumonia Viral/patologia , RNA Mensageiro/genética , RNA Viral/genética , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Sintéticas , Vacinas Virais/biossíntese , Vacinas Virais/genética
7.
Immunity ; 53(4): 864-877.e5, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-32791036

RESUMO

The SARS-CoV-2 pandemic has resulted in millions of infections, yet the role of host immune responses in early COVID-19 pathogenesis remains unclear. By investigating 17 acute and 24 convalescent patients, we found that acute SARS-CoV-2 infection resulted in broad immune cell reduction including T, natural killer, monocyte, and dendritic cells (DCs). DCs were significantly reduced with functional impairment, and ratios of conventional DCs to plasmacytoid DCs were increased among acute severe patients. Besides lymphocytopenia, although neutralizing antibodies were rapidly and abundantly generated in patients, there were delayed receptor binding domain (RBD)- and nucleocapsid protein (NP)-specific T cell responses during the first 3 weeks after symptoms onset. Moreover, acute RBD- and NP-specific T cell responses included relatively more CD4 T cells than CD8 T cells. Our findings provided evidence that impaired DCs, together with timely inverted strong antibody but weak CD8 T cell responses, could contribute to acute COVID-19 pathogenesis and have implications for vaccine development.


Assuntos
Betacoronavirus/patogenicidade , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por Coronavirus/imunologia , Células Dendríticas/imunologia , Diabetes Mellitus/imunologia , Hipertensão/imunologia , Pneumonia Viral/imunologia , Adulto , Idoso , Anticorpos Neutralizantes/biossíntese , Anticorpos Antivirais/biossíntese , Betacoronavirus/imunologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/patologia , Linfócitos T CD8-Positivos/virologia , Convalescença , Infecções por Coronavirus/complicações , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Células Dendríticas/patologia , Células Dendríticas/virologia , Complicações do Diabetes , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/virologia , Progressão da Doença , Feminino , Humanos , Hipertensão/complicações , Hipertensão/diagnóstico , Hipertensão/virologia , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/patologia , Células Matadoras Naturais/virologia , Ativação Linfocitária , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Monócitos/imunologia , Monócitos/patologia , Monócitos/virologia , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia , Índice de Gravidade de Doença
8.
Arch Virol ; 165(10): 2249-2258, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32696270

RESUMO

While infectious bursal disease virus (IBDV) mainly targets immature B cells and causes T cell infiltration in the bursa of Fabricius (BF) of chickens, the effect of IBDV infection on the properties of T cells and relevant cytokine production in avian gut-associated lymphoid tissues (GALTs) remains unknown. Here, we show that while the CD8+ T cell subset is not affected, IBDV infection decreases the percentage of CD4+ T cells in the cecal tonsil (CT), but not in esophagus tonsil, pylorus tonsil, and Meckel's diverticulum of GALTs, in contrast to BF and spleen, in which the proportion of CD4+ cells increases upon IBDV infection. Further, IBDV infection upregulates IFN-γ, IL-10, and the T cell checkpoint receptor LAG-3 mRNA expression in BF. In contrast, in CTs, IBDV infection significantly increases the production of IFN-ß and CTLA-4 mRNA, while no significant effect is seen in the case of IFN-γ, IL-10 and LAG-3. Together, our data reveal differential modulation of T cell subsets and proinflammatory cytokine production in different lymphoid tissues during the course of IBDV infection.


Assuntos
Subpopulações de Linfócitos B/imunologia , Infecções por Birnaviridae/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Regulação da Expressão Gênica/imunologia , Doenças das Aves Domésticas/imunologia , Animais , Antígenos CD/genética , Antígenos CD/imunologia , Subpopulações de Linfócitos B/virologia , Infecções por Birnaviridae/genética , Infecções por Birnaviridae/patologia , Infecções por Birnaviridae/virologia , Bolsa de Fabricius/imunologia , Bolsa de Fabricius/virologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/virologia , Antígeno CTLA-4/genética , Antígeno CTLA-4/imunologia , Galinhas/virologia , Vírus da Doença Infecciosa da Bursa/crescimento & desenvolvimento , Vírus da Doença Infecciosa da Bursa/imunologia , Vírus da Doença Infecciosa da Bursa/patogenicidade , Interferon beta/genética , Interferon beta/imunologia , Interferon gama/genética , Interferon gama/imunologia , Interleucina-10/genética , Interleucina-10/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/virologia , Tonsila Palatina/imunologia , Tonsila Palatina/virologia , Doenças das Aves Domésticas/genética , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/virologia
9.
Clin Immunol ; 217: 108486, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32479985

RESUMO

The lymphopenia exhibited in patients with COVID-19 has been associated with a worse prognosis in the development of the disease. To understand the factors associated with a worse evolution of COVID-19, we analyzed comorbidities, indicators of inflammation such as CRP and the ratio of neutrophils/lymphocytes, as well as the count of blood cells with T-lymphocyte subtypes in 172 hospitalized patients with COVID-19 pneumonia. Patients were grouped according to their needs for mechanical ventilation (ICU care) or not. Within the comorbidities studied, obesity was the only associated with greater severity and ICU admission. Both the percentage and the absolute number of neutrophils were higher in patients needing ICU care than non-ICU patients, whereas absolute lymphocyte count, and especially the percentage of lymphocytes, presented a deep decline in critical patients. There was no difference between the two groups of patients for CD4 T-lymphocytes, neither in percentage of lymphocyte nor in absolute number, however for CD8 T-cells the differences were significant for both parameters which were in decline in ICU patients. There was a firm correlation between the highest values of inflammation indicators with the decrease in percentage of CD8 T-lymphocytes. This effect was not seen with CD4 cells. Obesity together with lymphopenia, especially whether preferentially affects to CD8 T- lymphocytes, are factors that can predict a poor prognosis in patients with COVID-19.


Assuntos
Betacoronavirus/patogenicidade , Linfócitos T CD8-Positivos/patologia , Infecções por Coronavirus/imunologia , Linfopenia/imunologia , Neutrófilos/patologia , Obesidade/imunologia , Pneumonia Viral/imunologia , Idoso , Idoso de 80 Anos ou mais , Betacoronavirus/imunologia , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Estudos de Casos e Controles , Infecções por Coronavirus/complicações , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/terapia , Feminino , Humanos , Unidades de Terapia Intensiva , Contagem de Linfócitos , Linfopenia/complicações , Linfopenia/mortalidade , Linfopenia/terapia , Masculino , Pessoa de Meia-Idade , Neutrófilos/imunologia , Neutrófilos/virologia , Obesidade/complicações , Obesidade/mortalidade , Obesidade/terapia , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/mortalidade , Pneumonia Viral/terapia , Prognóstico , Respiração Artificial , Estudos Retrospectivos , Índice de Gravidade de Doença , Análise de Sobrevida
10.
Hematol Oncol ; 38(4): 554-559, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32583904

RESUMO

Ruxolitinib is effective in myeloproliferative neoplasms (MPN) but can cause reactivation of silent infections. We aimed at evaluating viral load and T-cell responses to human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in a cohort of 25 MPN patients treated with ruxolitinib. EBV-DNA and HCMV-DNA were quantified monthly using real-time polimerase chain reaction (PCR) on peripheral blood samples, and T-cell subsets were analyzed by flowcytometry. HCMV and EBV-directed T-cell responses were evaluated using the IFN-γ ELISPOT assay. Most patients had CD4+ and/or CD8+ T-cells below the normal range; these reductions were related to the duration of ruxolitinib treatment. In fact, reduced T-lymphocytes' subsets were found in 93% of patients treated for ≥5 years and in 45% of those treated for <5 years (P = .021). The former also had lower median numbers of CD4+ and CD8+ cells. Subclinical reactivation of EBV and HCMV occurred in 76% and 8% of patients. We observed a trend to an inverse relationship between EBV and CMV-specific CD4+ and CD8+ T-cell responses and viral load, and a trend to an inverse correlation with ruxolitinib dose. Therefore, our data suggest that the ruxolitinib treatment may interfere with immunosurveillance against EBV and HCMV.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por Citomegalovirus/imunologia , Infecções por Vírus Epstein-Barr/imunologia , Transtornos Mieloproliferativos/imunologia , Pirazóis/farmacologia , Ativação Viral/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/virologia , Citomegalovirus/efeitos dos fármacos , Citomegalovirus/imunologia , Infecções por Citomegalovirus/tratamento farmacológico , Infecções por Citomegalovirus/virologia , Infecções por Vírus Epstein-Barr/tratamento farmacológico , Infecções por Vírus Epstein-Barr/virologia , Feminino , Seguimentos , Herpesvirus Humano 4/efeitos dos fármacos , Herpesvirus Humano 4/imunologia , Humanos , Interferon gama/metabolismo , Masculino , Pessoa de Meia-Idade , Transtornos Mieloproliferativos/tratamento farmacológico , Transtornos Mieloproliferativos/virologia , Prognóstico , Taxa de Sobrevida , Carga Viral , Ativação Viral/efeitos dos fármacos
11.
Immunity ; 52(5): 808-824.e7, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32433949

RESUMO

Tissue-resident memory CD8+ T cells (Trm) provide host protection through continuous surveillance of non-lymphoid tissues. Using single-cell RNA-sequencing (scRNA-seq) and genetic reporter mice, we identified discrete lineages of intestinal antigen-specific CD8+ T cells, including a Blimp1hiId3lo tissue-resident effector cell population most prominent in the early phase of acute viral and bacterial infections and a molecularly distinct Blimp1loId3hi tissue-resident memory population that subsequently accumulated at later infection time points. These Trm populations exhibited distinct cytokine production, secondary memory potential, and transcriptional programs including differential roles for transcriptional regulators Blimp1, T-bet, Id2, and Id3 in supporting and maintaining intestinal Trm. Extending our analysis to malignant tissue, we also identified discrete populations of effector-like and memory-like CD8+ T cell populations with tissue-resident gene-expression signatures that shared features of terminally exhausted and progenitor-exhausted T cells, respectively. Our findings provide insight into the development and functional heterogeneity of Trm cells, which has implications for enhancing vaccination and immunotherapy approaches.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Memória Imunológica/imunologia , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Neoplasias/terapia , Animais , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/virologia , Células Cultivadas , Imunoterapia/métodos , Proteína 2 Inibidora de Diferenciação/genética , Proteína 2 Inibidora de Diferenciação/imunologia , Proteína 2 Inibidora de Diferenciação/metabolismo , Proteínas Inibidoras de Diferenciação/genética , Proteínas Inibidoras de Diferenciação/imunologia , Proteínas Inibidoras de Diferenciação/metabolismo , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/fisiologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Neoplasias/imunologia , Fator 1 de Ligação ao Domínio I Regulador Positivo/genética , Fator 1 de Ligação ao Domínio I Regulador Positivo/imunologia , Fator 1 de Ligação ao Domínio I Regulador Positivo/metabolismo
12.
Nat Med ; 26(6): 842-844, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32398875

RESUMO

Respiratory immune characteristics associated with Coronavirus Disease 2019 (COVID-19) severity are currently unclear. We characterized bronchoalveolar lavage fluid immune cells from patients with varying severity of COVID-19 and from healthy people by using single-cell RNA sequencing. Proinflammatory monocyte-derived macrophages were abundant in the bronchoalveolar lavage fluid from patients with severe COVID-9. Moderate cases were characterized by the presence of highly clonally expanded CD8+ T cells. This atlas of the bronchoalveolar immune microenvironment suggests potential mechanisms underlying pathogenesis and recovery in COVID-19.


Assuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/patologia , Pneumonia Viral/imunologia , Pneumonia Viral/patologia , Análise de Célula Única , Líquido da Lavagem Broncoalveolar/imunologia , Líquido da Lavagem Broncoalveolar/virologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Humanos , Pandemias , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia
13.
Nat Commun ; 11(1): 2421, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415086

RESUMO

Zika virus (ZIKV) is a mosquito-borne pathogen with increasing public health significance. To characterize immune responses to ZIKV, here we examine transcriptional signatures of CD4 T, CD8 T, B, and NK cells, monocytes, myeloid dendritic cells (mDCs), and plasmacytoid dendritic cells (pDCs) from three individuals with ZIKV infection. While gene expression patterns from most cell subsets display signs of impaired antiviral immune activity, pDCs from infected host have distinct transcriptional response associated with activation of innate immune recognition and type I interferon signaling pathways, but downregulation of key host factors known to support ZIKV replication steps; meanwhile, pDCs exhibit a unique expression pattern of gene modules that are correlated with alternative cell populations, suggesting collaborative interactions between pDCs and other immune cells, particularly B cells. Together, these results point towards a discrete but integrative function of pDCs in the human immune responses to ZIKV infection.


Assuntos
Células Dendríticas/imunologia , Infecção por Zika virus/imunologia , Adulto , Animais , Linfócitos B/virologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/virologia , Células Cultivadas , Culicidae , Células Dendríticas/virologia , Feminino , Perfilação da Expressão Gênica , Humanos , Imunidade Inata , Células Matadoras Naturais/virologia , Leucócitos Mononucleares/virologia , Monócitos/metabolismo , Monócitos/virologia , Células Mieloides/virologia , Transcrição Genética , Replicação Viral , Zika virus/imunologia , Infecção por Zika virus/virologia
14.
Blood Cells Mol Dis ; 83: 102437, 2020 07.
Artigo em Inglês | MEDLINE | ID: covidwho-47354

RESUMO

BACKGROUND: Cell-mediated immunity including T-cells (T helper and cytotoxic) plays an essential role in efficient antiviral responses against coronavirus disease-2019 (COVID-19). Therefore, in this study, we evaluated the ratio and expression of CD4 and CD8 markers in COVID-19 patients to clarify the immune characterizations of CD4 and CD8 T-cells in COVID-19 patients. METHODS: Peripheral blood samples of 25 COVID-19 patients and 25 normal individuals with similar age and sex as the control group were collected. White blood cells, platelets, and lymphocytes were counted and CD4 and CD8 T lymphocytes were evaluated by flow cytometry. RESULTS: The number of white blood cells, lymphocytes, and platelets were reduced significantly in COVID-19 patients (P < 0.05). The difference in CD4:CD8 ratio, CD4 T-cell frequency, CD8 T-cell frequency, and CD4 mean fluorescence intensity (MFI) was not significant between COVID-19 patients and healthy individuals (P > 0.05); however, the CD8 MFI increased significantly in COVID-19 infected patients (P < 0.05). CONCLUSION: Although, there is no significant difference in the ratio of CD4 to CD8 between two groups, the expression level of CD8 in COVID-19 patients was significantly higher than the normal individuals. This result suggested that the cellular immune responses triggered by COVID-19 infection were developed through overexpression of CD8 and hyperactivation of cytotoxic T lymphocytes.


Assuntos
Betacoronavirus/imunologia , Antígenos CD8/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por Coronavirus/imunologia , Imunidade Celular , Pneumonia Viral/imunologia , Betacoronavirus/isolamento & purificação , Biomarcadores/análise , Relação CD4-CD8 , Antígenos CD8/análise , Linfócitos T CD8-Positivos/virologia , Infecções por Coronavirus/sangue , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Feminino , Humanos , Contagem de Linfócitos , Masculino , Pandemias , Contagem de Plaquetas , Pneumonia Viral/sangue , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia
15.
Blood Cells Mol Dis ; 83: 102437, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32325421

RESUMO

BACKGROUND: Cell-mediated immunity including T-cells (T helper and cytotoxic) plays an essential role in efficient antiviral responses against coronavirus disease-2019 (COVID-19). Therefore, in this study, we evaluated the ratio and expression of CD4 and CD8 markers in COVID-19 patients to clarify the immune characterizations of CD4 and CD8 T-cells in COVID-19 patients. METHODS: Peripheral blood samples of 25 COVID-19 patients and 25 normal individuals with similar age and sex as the control group were collected. White blood cells, platelets, and lymphocytes were counted and CD4 and CD8 T lymphocytes were evaluated by flow cytometry. RESULTS: The number of white blood cells, lymphocytes, and platelets were reduced significantly in COVID-19 patients (P < 0.05). The difference in CD4:CD8 ratio, CD4 T-cell frequency, CD8 T-cell frequency, and CD4 mean fluorescence intensity (MFI) was not significant between COVID-19 patients and healthy individuals (P > 0.05); however, the CD8 MFI increased significantly in COVID-19 infected patients (P < 0.05). CONCLUSION: Although, there is no significant difference in the ratio of CD4 to CD8 between two groups, the expression level of CD8 in COVID-19 patients was significantly higher than the normal individuals. This result suggested that the cellular immune responses triggered by COVID-19 infection were developed through overexpression of CD8 and hyperactivation of cytotoxic T lymphocytes.


Assuntos
Betacoronavirus/imunologia , Antígenos CD8/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por Coronavirus/imunologia , Imunidade Celular , Pneumonia Viral/imunologia , Betacoronavirus/isolamento & purificação , Biomarcadores/análise , Relação CD4-CD8 , Antígenos CD8/análise , Linfócitos T CD8-Positivos/virologia , Infecções por Coronavirus/sangue , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Feminino , Humanos , Contagem de Linfócitos , Masculino , Pandemias , Contagem de Plaquetas , Pneumonia Viral/sangue , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia
16.
J Virol ; 94(12)2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32269122

RESUMO

Early and robust T cell responses have been associated with survival from Lassa fever (LF), but the Lassa virus-specific memory responses have not been well characterized. Regions within the virus surface glycoprotein (GPC) and nucleoprotein (NP) are the main targets of the Lassa virus-specific T cell responses, but, to date, only a few T cell epitopes within these proteins have been identified. We identified GPC and NP regions containing T cell epitopes and HLA haplotypes from LF survivors and used predictive HLA-binding algorithms to identify putative epitopes, which were then experimentally tested using autologous survivor samples. We identified 12 CD8-positive (CD8+) T cell epitopes, including epitopes common to both Nigerian and Sierra Leonean survivors. These data should be useful for the identification of dominant Lassa virus-specific T cell responses in Lassa fever survivors and vaccinated individuals as well as for designing vaccines that elicit cell-mediated immunity.IMPORTANCE The high morbidity and mortality associated with clinical cases of Lassa fever, together with the lack of licensed vaccines and limited and partially effective interventions, make Lassa virus (LASV) an important health concern in its regions of endemicity in West Africa. Previous infection with LASV protects from disease after subsequent exposure, providing a framework for designing vaccines to elicit similar protective immunity. Multiple major lineages of LASV circulate in West Africa, and therefore, ideal vaccine candidates should elicit immunity to all lineages. We therefore sought to identify common T cell epitopes between Lassa fever survivors from Sierra Leone and Nigeria, where distinct lineages circulate. We identified three such epitopes derived from highly conserved regions within LASV proteins. In this process, we also identified nine other T cell epitopes. These data should help in the design of an effective pan-LASV vaccine.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/química , Febre Lassa/imunologia , Vírus Lassa/imunologia , Nucleoproteínas/imunologia , Proteínas do Envelope Viral/imunologia , Adolescente , Sequência de Aminoácidos , Animais , Anticorpos Antivirais/biossíntese , Antígenos Virais/química , Antígenos Virais/genética , Antígenos Virais/imunologia , Linfócitos T CD8-Positivos/virologia , Criança , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Feminino , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/imunologia , Antígenos HLA-DQ/genética , Antígenos HLA-DQ/imunologia , Haplótipos , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Soros Imunes/análise , Memória Imunológica , Febre Lassa/genética , Febre Lassa/patologia , Vírus Lassa/patogenicidade , Masculino , Nigéria , Nucleoproteínas/genética , Serra Leoa , Sobreviventes , Proteínas do Envelope Viral/genética , Adulto Jovem
17.
J Leukoc Biol ; 107(6): 953-970, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32125017

RESUMO

Tissue resident memory T cells (Trm) are critical for local protection against reinfection. The accumulation of T cells in the tissues requires a post-priming signal from TNFR superfamily members, referred to as signal 4. Glucocorticoid-induced TNFR-related protein (GITR; TNFRSF18) signaling is important for this post-priming signal and for Trm formation during respiratory infection with influenza virus. As GITR signaling impacts both effector T cell accumulation and Trm formation, we asked if GITR differentially affects subsets of effector cells with different memory potential. Effector CD4+ T cells can be subdivided into 2 populations based on expression of lymphocyte antigen 6C (Ly6C), whereas effector CD8+ cells can be divided into 3 populations based on Ly6C and CX3CR1. The Ly6Chi and CX3CR1hi T cell populations represent the most differentiated effector T cells. Upon transfer, the Ly6Clo CD4+ effector T cells preferentially enter the lung parenchyma, compared to the Ly6Chi CD4+ T cells. We show that GITR had a similar effect on the accumulation of both the Ly6Chi and Ly6Clo CD4+ T cell subsets. In contrast, whereas GITR increased the accumulation of all three CD8+ T cell subsets defined by CX3CR1 and Ly6C expression, it had a more substantial effect on the least differentiated Ly6Clo CX3CR1lo subset. Moreover, GITR selectively up-regulated CXCR6 on the less differentiated CX3CR1lo CD8+ T cell subsets and induced a small but significant increase in CD127 selectively on the Ly6Clo CD4+ T cell subset. Thus, GITR contributes to accumulation of both differentiated effector cells as well as memory precursors, but with some differences between subsets.


Assuntos
Antígenos Ly/genética , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Proteína Relacionada a TNFR Induzida por Glucocorticoide/genética , Vírus da Influenza A/imunologia , Infecções por Orthomyxoviridae/imunologia , Animais , Antígenos Ly/imunologia , Linfócitos T CD4-Positivos/classificação , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/classificação , Linfócitos T CD8-Positivos/patologia , Linfócitos T CD8-Positivos/virologia , Receptor 1 de Quimiocina CX3C/genética , Receptor 1 de Quimiocina CX3C/imunologia , Diferenciação Celular , Movimento Celular , Feminino , Regulação da Expressão Gênica , Proteína Relacionada a TNFR Induzida por Glucocorticoide/deficiência , Proteína Relacionada a TNFR Induzida por Glucocorticoide/imunologia , Memória Imunológica , Imunofenotipagem , Vírus da Influenza A/crescimento & desenvolvimento , Subunidade alfa de Receptor de Interleucina-7/genética , Subunidade alfa de Receptor de Interleucina-7/imunologia , Pulmão/imunologia , Pulmão/patologia , Pulmão/virologia , Contagem de Linfócitos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infecções por Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/virologia , Transdução de Sinais , Baço/imunologia , Baço/patologia , Baço/virologia
18.
Nat Med ; 26(2): 222-227, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32015556

RESUMO

Combination antiretroviral therapy (ART) is highly effective in controlling human immunodeficiency virus (HIV)-1 but requires lifelong medication due to the existence of a latent viral reservoir1,2. Potent broadly neutralizing antibodies (bNAbs) represent a potential alternative or adjuvant to ART. In addition to suppressing viremia, bNAbs may have T cell immunomodulatory effects as seen for other forms of immunotherapy3. However, this has not been established in individuals who are infected with HIV-1. Here, we document increased HIV-1 Gag-specific CD8+ T cell responses in the peripheral blood of all nine study participants who were infected with HIV-1 with suppressed blood viremia, while receiving bNAb therapy during ART interruption4. Increased CD4+ T cell responses were detected in eight individuals. The increased T cell responses were due both to newly detectable reactivity to HIV-1 Gag epitopes and the expansion of pre-existing measurable responses. These data demonstrate that bNAb therapy during ART interruption is associated with enhanced HIV-1-specific T cell responses. Whether these augmented T cell responses can contribute to bNAb-mediated viral control remains to be determined.


Assuntos
Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/terapia , Imunoterapia/métodos , Linfócitos T/imunologia , Adulto , Anticorpos Neutralizantes/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Epitopos/imunologia , Feminino , Produtos do Gene gag/metabolismo , Infecções por HIV/virologia , HIV-1 , Humanos , Sistema Imunitário , Interferon gama/imunologia , Masculino , Pessoa de Meia-Idade , Linfócitos T/virologia , Viremia
19.
J Virol ; 94(9)2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32102875

RESUMO

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes explosive epidemics of a febrile illness characterized by debilitating arthralgia and arthritis that can endure for months to years following infection. In mouse models, CHIKV persists in joint tissues for weeks to months and is associated with chronic synovitis. Using a recombinant CHIKV strain encoding a CD8+ T cell receptor epitope from ovalbumin, as well as a viral peptide-specific major histocompatibility complex class I tetramer, we interrogated CD8+ T cell responses during CHIKV infection. Epitope-specific CD8+ T cells, which were reduced in Batf3 -/- and Wdfy4 -/- mice with known defects in antigen cross-presentation, accumulated in joint tissue and the spleen. Antigen-specific ex vivo restimulation assays and in vivo killing assays demonstrated that CD8+ T cells produce cytokine and have cytolytic activity. Despite the induction of a virus-specific CD8+ T cell response, the CHIKV burden in joint-associated tissues and the spleen were equivalent in wild-type (WT) and CD8α-/- mice during both the acute and the chronic phases of infection. In comparison, CD8+ T cells were essential for the control of acute and chronic lymphocytic choriomeningitis virus infection in the joint and spleen. Moreover, adoptive transfer of virus-specific effector CD8+ T cells or immunization with a vaccine that induces virus-specific effector CD8+ T cells prior to infection enhanced the clearance of CHIKV infection in the spleen but had a minimal impact on CHIKV infection in the joint. Collectively, these data suggest that CHIKV establishes and maintains a persistent infection in joint-associated tissue in part by evading CD8+ T cell immunity.IMPORTANCE CHIKV is a reemerging mosquito-transmitted virus that in the last decade has spread into Europe, Asia, the Pacific Region, and the Americas. Joint pain, swelling, and stiffness can endure for months to years after CHIKV infection, and epidemics have a severe economic impact. Elucidating the mechanisms by which CHIKV subverts antiviral immunity to establish and maintain a persistent infection may lead to the development of new therapeutic strategies against chronic CHIKV disease. In this study, we found that CHIKV establishes and maintains a persistent infection in joint-associated tissue in part by evading antiviral CD8+ T cell immunity. Thus, immunomodulatory therapies that improve CD8+ T cell immune surveillance and clearance of CHIKV infection could be a strategy for mitigating chronic CHIKV disease.


Assuntos
Febre de Chikungunya/imunologia , Vírus Chikungunya/metabolismo , Articulações/virologia , Imunidade Adaptativa/imunologia , Transferência Adotiva/métodos , Animais , Anticorpos Antivirais/imunologia , Antivirais/uso terapêutico , Artrite/virologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Febre de Chikungunya/metabolismo , Vírus Chikungunya/patogenicidade , Vírus Chikungunya/fisiologia , Modelos Animais de Doenças , Epitopos de Linfócito T/imunologia , Feminino , Imunização , Articulações/imunologia , Lectinas Tipo C , Masculino , Camundongos , Receptores Mitogênicos
20.
Proc Natl Acad Sci U S A ; 117(10): 5420-5429, 2020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32094187

RESUMO

Chronic infection provokes alterations in inflammatory and suppressive pathways that potentially affect the function and integrity of multiple tissues, impacting both ongoing immune control and restorative immune therapies. Here we demonstrate that chronic lymphocytic choriomeningitis virus infection rapidly triggers severe thymic depletion, mediated by CD8 T cell-intrinsic type I interferon (IFN) and signal transducer and activator of transcription 2 (Stat2) signaling. Occurring temporal to T cell exhaustion, thymic cellularity reconstituted despite ongoing viral replication, with a rapid secondary thymic depletion following immune restoration by anti-programmed death-ligand 1 (PDL1) blockade. Therapeutic hematopoietic stem cell transplant (HSCT) during chronic infection generated new antiviral CD8 T cells, despite sustained virus replication in the thymus, indicating an impairment in negative selection. Consequently, low amounts of high-affinity self-reactive T cells also escaped the thymus following HSCT during chronic infection. Thus, by altering the stringency and partially impairing negative selection, the host generates new virus-specific T cells to replenish the fight against the chronic infection, but also has the potentially dangerous effect of enabling the escape of self-reactive T cells.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Interferon Tipo I/metabolismo , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/patologia , Vírus da Coriomeningite Linfocítica , Timo/patologia , Timo/virologia , Animais , Atrofia/virologia , Antígeno B7-H1/antagonistas & inibidores , Doença Crônica , Transplante de Células-Tronco Hematopoéticas , Interferon Tipo I/genética , Coriomeningite Linfocítica/terapia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fator de Transcrição STAT2/metabolismo , Transdução de Sinais , Replicação Viral
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