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1.
PLoS Pathog ; 15(12): e1008248, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31869393

RESUMO

Viral and/or host factors that are directly responsible for the acute versus chronic outcome of hepatitis B virus (HBV) infection have not been identified yet. Information on immune response during the early stages of HBV infection in humans is mainly derived from blood samples of patients with acute hepatitis B (AHB), which are usually obtained after the onset of clinical symptoms. Features of intrahepatic immune response in these patients are less studied due to the difficulty of obtaining multiple liver biopsies. Woodchuck hepatitis virus (WHV) infection in woodchucks is a model for HBV infection in humans. In the present study, five adult woodchucks were experimentally infected with WHV and then followed for 18 weeks. Blood and liver tissues were frequently collected for assaying markers of WHV replication and innate and adaptive immune responses. Liver tissues were further analyzed for pathological changes and stained for important immune cell subsets and cytokines. The increase and subsequent decline of viral replication markers in serum and liver, the elicitation of antibodies against viral proteins, and the induction of virus-specific T-cell responses indicated eventual resolution of acute WHV infection in all animals. Intrahepatic innate immune makers stayed unchanged immediately after the infection, but increased markedly during resolution, as determined by changes in transcript levels. The presence of interferon-gamma and expression of natural killer (NK) cell markers suggested that a non-cytolytic response mechanism is involved in the initial viral control in liver. This was followed by the expression of T-cell markers and cytolytic effector molecules, indicating the induction of a cytolytic response mechanism. Parallel increases in regulatory T-cell markers suggested that this cell subset participates in the overall immune cell infiltration in liver and/or has a role in regulating AHB induced by the cytolytic response mechanism. Since the transcript levels of immune cell markers in blood, when detectable, were lower than in liver, and the kinetics, except for NK-cells and interferon-gamma, did not correlate well with their intrahepatic expression, this further indicated enrichment of immune cells within liver. Conclusion: The coordinated interplay of innate and adaptive immunity mediates viral clearance in the woodchuck animal model of HBV infection. The initial presence of NK-cell associated interferon-gamma response points to an important role of this cytokine in HBV resolution.


Assuntos
Imunidade Adaptativa , Vírus da Hepatite B da Marmota/patogenicidade , Hepatite B/virologia , Imunidade Inata , Células Matadoras Naturais/virologia , Marmota/virologia , Envelhecimento , Animais , Vírus da Hepatite B da Marmota/imunologia , Interferon gama/metabolismo , Células Matadoras Naturais/metabolismo , Fígado/patologia , Fígado/virologia , Linfócitos T/imunologia , Linfócitos T/virologia , Replicação Viral/imunologia
2.
J Immunol Res ; 2019: 8028725, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31612153

RESUMO

Influenza virus infection is a serious threat to humans and animals, with the potential to cause severe pneumonia and death. Annual vaccination strategies are a mainstay to prevent complications related to influenza. However, protection from the emerging subtypes of influenza A viruses (IAV) even in vaccinated individuals is challenging. Innate immune cells are the first cells to respond to IAV infection in the respiratory tract. Virus replication-induced production of cytokines from airway epithelium recruits innate immune cells to the site of infection. These leukocytes, namely, neutrophils, monocytes, macrophages, dendritic cells, eosinophils, natural killer cells, innate lymphoid cells, and γδ T cells, become activated in response to IAV, to contain the virus and protect the airway epithelium while triggering the adaptive arm of the immune system. This review addresses different anti-influenza virus schemes of innate immune cells and how these cells fine-tune the balance between immunoprotection and immunopathology during IAV infection. Detailed understanding on how these innate responders execute anti-influenza activity will help to identify novel therapeutic targets to halt IAV replication and associated immunopathology.


Assuntos
Vírus da Influenza A/imunologia , Influenza Humana/imunologia , Leucócitos/virologia , Citocinas , Células Dendríticas/imunologia , Células Dendríticas/virologia , Humanos , Imunidade Inata , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/virologia , Leucócitos/imunologia , Macrófagos/imunologia , Macrófagos/virologia , Monócitos/imunologia , Monócitos/virologia , Replicação Viral/imunologia
3.
Int J Mol Sci ; 20(18)2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31547251

RESUMO

Natural Killer (NK) cells are a type of cytotoxic lymphocytes that play an important role in the innate immune system. They are of particular interest for their role in elimination of intracellular pathogens, viral infection and tumor cells. As such, numerous strategies are being investigated in order to potentiate their functions. One of these techniques aims at promoting the function of their activating receptors. However, different observations have revealed that providing activation signals could actually be counterproductive and lead to NK cells' hyporesponsiveness. This phenomenon can occur during the NK cell education process, under pathological conditions, but also after treatment with different agents, including cytokines, that are promising tools to boost NK cell function. In this review, we aim to highlight the different circumstances where NK cells become hyporesponsive and the methods that could be used to restore their functionality.


Assuntos
Células Matadoras Naturais/imunologia , Neoplasias/imunologia , Viroses/imunologia , Animais , Citocinas/imunologia , Humanos , Imunidade Inata , Células Matadoras Naturais/patologia , Células Matadoras Naturais/virologia , Neoplasias/patologia , Neoplasias/virologia , Viroses/patologia , Viroses/virologia , Vírus/imunologia
4.
Int J Mol Sci ; 20(15)2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31366013

RESUMO

Natural Killer (NK) cells play a critical role in host defense against viral infections. The mechanisms of recognition and killing of virus-infected cells mediated by NK cells are still only partially defined. Several viruses induce, on the surface of target cells, the expression of molecules that are specifically recognized by NK cell-activating receptors. The main NK cell-activating receptors involved in the recognition and killing of virus-infected cells are NKG2D and DNAM-1. In particular, ligands for DNAM-1 are nectin/nectin-like molecules involved also in mechanisms allowing viral infection. Viruses adopt several immune evasion strategies, including those affecting NK cell-mediated immune surveillance, causing persistent viral infection and the development of virus-associated diseases. The virus's immune evasion efficacy depends on molecules differently expressed during the various phases of infection. In this review, we overview the molecular strategies adopted by viruses, specifically cytomegalovirus (CMV), human immunodeficiency virus (HIV-1), herpes virus (HSV), Epstein-Barr virus (EBV) and hepatitis C virus (HCV), aiming to evade NK cell-mediated surveillance, with a special focus on the modulation of DNAM-1 activating receptor and its ligands in various phases of the viral life cycle. The increasing understanding of mechanisms involved in the modulation of activating ligands, together with those mediating the viral immune evasion strategies, would provide critical tools leading to design novel NK cell-based immunotherapies aiming at viral infection control, thus improving cure strategies of virus-associated diseases.


Assuntos
Antígenos de Diferenciação de Linfócitos T/metabolismo , Vigilância Imunológica , Células Matadoras Naturais/imunologia , Viroses/imunologia , Animais , Humanos , Células Matadoras Naturais/virologia , Nectinas/metabolismo , Viroses/virologia , Replicação Viral
5.
Diagn Pathol ; 14(1): 82, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31315684

RESUMO

BACKGROUND: Hydroa vacciniforme-like lymphoproliferative disorder (HV-LPD) is a cutaneous form of chronic active Epstein-Barr virus (EBV) infection, which occurs mainly in children in Latin America and Asia. It can progress to systemic lymphoma. However, prognostic factors and treatment remain unclear. METHODS: This retrospective study reviewed the clinical, morphologic, immunophenotypical features, and clinical treatment of 19 patients with HV-LPD. RESULTS: All 19 patients had skin lesions in the face, extremities, or areas unexposed to the sun, including edema, blistering, ulceration, and scarring. The course was slowly progressive and relapsing. Histopathology showed an atypical lymphocytic infiltrate in the dermis and/or subcutaneous tissue. The lesions had a cytotoxic T/NK-cell immunophenotype. Among 19 patients, 7 (37%) exhibited CD4+ T cells, 5 (26%) exhibited CD8+ T cells, and 7 (37%) exhibited CD56+ cells. Of 12 cases with a T-cell phenotype, molecular analyses demonstrated that 7 had monoclonal rearrangements in the T-cell receptor genes. Three cases had an NK-cell phenotype and had polyclonal rearrangements in the TCR genes. All cases were associated with EBV infections. Among 19 patients, 9 (47.4%) received chemotherapy. Only one patient received allogeneic transplantation and EBV-specific cytotoxic T lymphocyte treatment after chemotherapy. That patient was the only one alive without disease at the latest follow up. Nine patients died of systemic lymphoma with disease progression, indicating irreversible process. CONCLUSIONS: This study confirmed that HV-LPD is a broad-spectrum EBV+ lymphoproliferative disorder. It progressed to EBV+ systemic T/NK lymphoma, although some patients had a more indolent, chronic course. Cytopenia, elevated lactate dehydrogenase, destructive-multiorgan involvement, and older age were poor prognostic factors. Only allogeneic transplantation was curative.


Assuntos
Hidroa Vaciniforme/patologia , Linfoma de Células T/patologia , Transtornos Linfoproliferativos/patologia , Recidiva Local de Neoplasia/patologia , Adolescente , Criança , Pré-Escolar , Infecções por Vírus Epstein-Barr/complicações , Feminino , Herpesvirus Humano 4/genética , Humanos , Hidroa Vaciniforme/diagnóstico , Hidroa Vaciniforme/virologia , Células Matadoras Naturais/patologia , Células Matadoras Naturais/virologia , Linfoma de Células T/virologia , Transtornos Linfoproliferativos/diagnóstico , Masculino , Prognóstico , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/virologia , Adulto Jovem
6.
Brain Dev ; 41(9): 820-825, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31208818

RESUMO

BACKGROUND: Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disorders (EBV-T/NK-LPD) is a group of rare disorders resulting from EBV-infected T/NK-cells. It manifests as a broad spectrum of clinical symptoms according to immunologic status and viral load of an infected patient. Here, we report a boy who developed central nervous system (CNS) vasculitis and myelopathy as possible neurologic manifestations of EBV-T/NK-LPD. CASE REPORT: A 16-year-old boy came to our hospital with a necrotic skin lesion on his right shoulder. He suffered from local skin reactions with high fevers after mosquito bites since he was 10 years old. During the evaluation of his skin lesion, he suddenly developed left facial palsy. Brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) showed acute infarctions of the pons and middle cerebellar peduncle and irregularities of both anterior inferior cerebellar arteries. Serologic testing showed an elevation of total Ig E levels, anti-VCA IgG levels, and anti-EA IgG titers. EBV DNA copy numbers of the whole blood and cerebrospinal fluid (CSF) were elevated. Biopsy of the right shoulder skin showed extranodal NK/T-cell lymphoma. According to clinical features and laboratory findings, he was diagnosed with EBV-T/NK-LPD. He was treated with chemotherapy and hematopoietic stem cell transplantation but developed recurrent infarctions during treatment. CONCLUSION: This case showed the diagnostic challenge of neurologic manifestations of EBV-T/NK-LPD. EBV-T/NK-LPD-associated CNS vasculitis needs to be considered as a differential diagnosis of CNS vasculitis, when it is accompanied by the typical clinical spectrum of EBV-T/NK-LPD such as severe mosquito bite allergy, extranodal NK/T-cell lymphoma.


Assuntos
Infecções por Vírus Epstein-Barr/complicações , Transtornos Linfoproliferativos/etiologia , Vasculite do Sistema Nervoso Central/etiologia , Adolescente , Diagnóstico Diferencial , Infecções por Vírus Epstein-Barr/diagnóstico , Infecções por Vírus Epstein-Barr/terapia , Humanos , Células Matadoras Naturais/virologia , Transtornos Linfoproliferativos/diagnóstico , Transtornos Linfoproliferativos/terapia , Masculino , Doenças da Medula Espinal/diagnóstico , Doenças da Medula Espinal/etiologia , Doenças da Medula Espinal/terapia , Vasculite do Sistema Nervoso Central/diagnóstico , Vasculite do Sistema Nervoso Central/terapia
7.
BMC Infect Dis ; 19(1): 433, 2019 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-31101076

RESUMO

BACKGROUND: Natural killer (NK) cells are part of the innate immune system and provide surveillance against viruses and cancers. The ability of NK cells to kill virus-infected cells depends on the balance between the effects of inhibitory and activating NK cell receptors. This study aimed to investigate the phenotypic profile and the functional capacity of NK cells in the context of HTLV-1 infection. METHODS: This cross-sectional study sequentially recruited HTLV-1 infected individuals with HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) and asymptomatic HTLV-1 (AS) from the Integrated and Multidisciplinary HTLV Center in Salvador, Brazil. Blood samples from healthy blood donors served as controls. NK cell surface receptors (NKG2D, KIR2DL2/KIR2DL3, NKp30, NKG2A, NKp46, TIM-3 and PD-1), intracellular cytolytic (Granzyme B, perforin) and functional markers (CD107a for degranulation, IFN-γ) were assayed by flow cytometry in the presence or absence of standard K562 target cells. In addition, cytotoxicity assays were performed in the presence or absence of anti-NKp30. RESULTS: The frequency of NKp30+ NK cells was significantly decreased in HAM/TSP patients [58%, Interquartile Range (IQR) 30-61] compared to controls (73%, IQR 54-79, p = 0.04). The production of cytolytic (perforin, granzyme B) and functional markers (CD107a and IFN-γ) was higher in unstimulated NK cells from HAM/TSP and AS patients compared to controls. By contrast, stimulation with K562 target cells did not alter the frequency of CD107a+ NK cells in HAM/TSP subjects compared to the other groups. Blockage of the NKp30 receptor was shown to decrease cytotoxic activity (CD107a) and IFN-γ expression only in asymptomatic HTLV-1-infected individuals. CONCLUSIONS: NK cells from individuals with a diagnosis of HAM/TSP present decreased expression of the activating receptor NKp30, in addition to elevated degranulation activity that remained unaffected after blocking the NKp30 receptor.


Assuntos
Células Matadoras Naturais/imunologia , Receptor 3 Desencadeador da Citotoxicidade Natural/metabolismo , Paraparesia Espástica Tropical/imunologia , Adulto , Anticorpos Monoclonais/farmacologia , Biomarcadores/metabolismo , Estudos Transversais , Feminino , Citometria de Fluxo , Granzimas/metabolismo , Infecções por HTLV-I/imunologia , Infecções por HTLV-I/virologia , Humanos , Interferon gama/metabolismo , Células K562 , Células Matadoras Naturais/metabolismo , Células Matadoras Naturais/virologia , Masculino , Pessoa de Meia-Idade , Receptor 3 Desencadeador da Citotoxicidade Natural/antagonistas & inibidores , Paraparesia Espástica Tropical/virologia , Perforina/metabolismo
9.
PLoS Pathog ; 15(4): e1007658, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30947296

RESUMO

Throughout evolution, cytomegaloviruses (CMVs) have been capturing genes from their hosts, employing the derived proteins to evade host immune defenses. We have recently reported the presence of a number of CD48 homologs (vCD48s) encoded by different pathogenic viruses, including several CMVs. However, their properties and biological relevance remain as yet unexplored. CD48, a cosignaling molecule expressed on the surface of most hematopoietic cells, modulates the function of natural killer (NK) and other cytotoxic cells by binding to its natural ligand 2B4 (CD244). Here, we have characterized A43, the vCD48 exhibiting the highest amino acid sequence identity with host CD48. A43, which is encoded by owl monkey CMV, is a soluble molecule released from the cell after being proteolytically processed through its membrane proximal region. A43 is expressed with immediate-early kinetics, yielding a protein that is rapidly detected in the supernatant of infected cells. Remarkably, surface plasmon resonance assays revealed that this viral protein binds to host 2B4 with high affinity and slow dissociation rates. We demonstrate that soluble A43 is capable to abrogate host CD48:2B4 interactions. Moreover, A43 strongly binds to human 2B4 and prevents 2B4-mediated NK-cell adhesion to target cells, therefore reducing the formation of conjugates and the establishment of immunological synapses between human NK cells and CD48-expressing target cells. Furthermore, in the presence of this viral protein, 2B4-mediated cytotoxicity and IFN-γ production by NK cells are severely impaired. In summary, we propose that A43 may serve as a functional soluble CD48 decoy receptor by binding and masking 2B4, thereby impeding effective NK cell immune control during viral infections. Thus, our findings provide a novel example of the immune evasion strategies developed by viruses.


Assuntos
Antígeno CD48/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Citotoxicidade Imunológica/imunologia , Células Matadoras Naturais/imunologia , Receptores Imunológicos/imunologia , Família de Moléculas de Sinalização da Ativação Linfocitária/imunologia , Antígeno CD48/metabolismo , Células Cultivadas , Infecções por Citomegalovirus/virologia , Humanos , Células Matadoras Naturais/metabolismo , Células Matadoras Naturais/virologia , Ativação Linfocitária , Receptores Imunológicos/metabolismo , Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismo
10.
PLoS Pathog ; 15(4): e1007725, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30995287

RESUMO

Besides their function in recognizing cancerous and virally infected cells, natural killer (NK) cells have the potential to shape adaptive immune responses. However, the mechanisms employed by NK cells to negatively regulate virus-specific CD8 T cell responses remain to be fully defined. Using activating receptor natural cytotoxicity receptor (NCR) 1 deficient (NCR1gfp/gfp) mice, we found increased numbers of virus-specific CD8 T cells, leading to enhanced virus control during acute LCMV infection. Furthermore, virus-specific CD8 T cells were more activated in the absence of NCR1, resulting in exacerbated immunopathology, documented by weight loss, and superior virus control early during chronic LCMV infection. Transfer experiments of virus-specific CD8 T cells into NCR1 deficient hosts revealed a direct cross talk between NK and CD8 T cells. Studies on the splenic microarchitecture revealed pronounced disorganization of T cells in infected NCR1gfp/gfp mice, resulting in enhanced immunopathology and disruption of the T cell niche upon chronic LCMV infection. Our data show a novel pathway employed by NK cells to regulate antiviral CD8 T cell responses, namely direct recognition and elimination of activated CD8 T cells via NCR1 early during infection to protect the host from an overshooting T cell response.


Assuntos
Antígenos Ly/metabolismo , Linfócitos T CD8-Positivos/imunologia , Citotoxicidade Imunológica/imunologia , Células Matadoras Naturais/imunologia , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Receptor 1 Desencadeador da Citotoxicidade Natural/metabolismo , Animais , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/virologia , Células Cultivadas , Células Matadoras Naturais/metabolismo , Células Matadoras Naturais/virologia , Ativação Linfocitária , Coriomeningite Linfocítica/virologia , Camundongos , Camundongos Endogâmicos C57BL
11.
Viruses ; 11(3)2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30870969

RESUMO

Natural killer (NK) cells are essential in the early immune response against viral infections, in particular through clearance of virus-infected cells. In return, viruses have evolved multiple mechanisms to evade NK cell-mediated viral clearance. Several unrelated viruses, including influenza virus, respiratory syncytial virus, and human immunodeficiency virus, can directly interfere with NK cell functioning through infection of these cells. Viral infection can lead to immune suppression, either by downregulation of the cytotoxic function or by triggering apoptosis, leading to depletion of NK cells. In contrast, some viruses induce proliferation or changes in the morphology of NK cells. In this review article, we provide a comprehensive overview of the viruses that have been reported to infect NK cells, we discuss their mechanisms of entry, and describe the interference with NK cell effector function and phenotype. Finally, we discuss the contribution of virus-infected NK cells to viral load. The development of specific therapeutics, such as viral entry inhibitors, could benefit from an enhanced understanding of viral infection of NK cells, opening up possibilities for the prevention of NK cell infection.


Assuntos
Evasão da Resposta Imune , Células Matadoras Naturais/virologia , Carga Viral , Viroses/imunologia , Vírus/imunologia , Humanos , Células Matadoras Naturais/imunologia , Orthomyxoviridae/imunologia , Orthomyxoviridae/fisiologia , Vírus Sinciciais Respiratórios/imunologia , Vírus Sinciciais Respiratórios/fisiologia , Viroses/prevenção & controle , Internalização do Vírus
13.
Viruses ; 11(3)2019 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-30857329

RESUMO

Expansion of natural killer (NK) cells expressing NKG2C occurs following human cytomegalovirus (HCMV) infection and is amplified by human immunodeficiency virus (HIV) co-infection. These NKG2C-expressing NK cells demonstrate enhanced CD16-dependent cytokine production and downregulate FcεRIγ and promyelocytic leukemia zinc finger protein (PLZF). Lacking NKG2C diminishes resistance to HIV infection, but whether this affects NK cell acquisition of superior antibody-dependent function is unclear. Therefore, our objective was to investigate whether HCMV-driven NK cell differentiation is impaired in NKG2Cnull HIV-infected individuals. Phenotypic (CD2, CD16, CD57, NKG2A, FcεRIγ, and PLZF expression) and functional (cytokine induction and cytotoxicity) properties were compared between HIV⁻infected NKG2Cnull and NKG2C-expressing groups. Cytokine production was compared following stimulation through natural cytotoxicity receptors or through CD16. Cytotoxicity was measured by anti-CD16-redirected lysis and by classical antibody-dependent cell-mediated cytotoxicity (ADCC) against anti-class I human leukocyte antigen (HLA) antibody-coated cells. Our data indicate highly similar HCMV-driven NK cell differentiation in HIV infection with or without NKG2C. While the fraction of mature (CD57pos) NK cells expressing CD2 (p = 0.009) or co-expressing CD2 and CD16 (p = 0.03) was significantly higher in NKG2Cnull HIV-infected individuals, there were no significant differences in NKG2A, FcεRIγ, or PLZF expression. The general phenotypic and functional equivalency observed suggests NKG2C-independent routes of HCMV-driven NK cell differentiation, which may involve increased CD2 expression.


Assuntos
Infecções por Citomegalovirus/imunologia , Citomegalovirus/patogenicidade , Infecções por HIV/imunologia , Células Matadoras Naturais/virologia , Subfamília C de Receptores Semelhantes a Lectina de Células NK/genética , Adulto , Citotoxicidade Celular Dependente de Anticorpos , Diferenciação Celular , Coinfecção/imunologia , Coinfecção/virologia , Citocinas/imunologia , Feminino , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/imunologia , Humanos , Células Matadoras Naturais/citologia , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Subfamília C de Receptores Semelhantes a Lectina de Células NK/imunologia , Proteína com Dedos de Zinco da Leucemia Promielocítica/genética , Proteína com Dedos de Zinco da Leucemia Promielocítica/imunologia , Receptores de IgE/genética , Receptores de IgE/imunologia , Receptores de IgG/genética , Receptores de IgG/imunologia
14.
J Virol ; 93(7)2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30700608

RESUMO

HIV infection is controlled immunologically in a small subset of infected individuals without antiretroviral therapy (ART), though the mechanism of control is unclear. CD8+ T cells are a critical component of HIV control in many immunological controllers. NK cells are also believed to have a role in controlling HIV infection, though their role is less well characterized. We used mass cytometry to simultaneously measure the levels of expression of 24 surface markers on peripheral NK cells from HIV-infected subjects with various degrees of HIV natural control; we then used machine learning to identify NK cell subpopulations that differentiate HIV controllers from noncontrollers. Using CITRUS (cluster identification, characterization, and regression), we identified 3 NK cell subpopulations that differentiated subjects with chronic HIV viremia (viremic noncontrollers [VNC]) from individuals with undetectable HIV viremia without ART (elite controllers [EC]). In a parallel approach, we identified 11 NK cell subpopulations that differentiated HIV-infected subject groups using k-means clustering after dimensionality reduction by t-neighbor stochastic neighbor embedding (tSNE) or linear discriminant analysis (LDA). Among these additional 11 subpopulations, the frequencies of 5 correlated with HIV DNA levels; importantly, significance was retained in 2 subpopulations in analyses that included only cohorts without detectable viremia. By comparing the surface marker expression patterns of all identified subpopulations, we revealed that the CD11b+ CD57- CD161+ Siglec-7+ subpopulation of CD56dim CD16+ NK cells are more abundant in EC and HIV-negative controls than in VNC and that the frequency of these cells correlated with HIV DNA levels. We hypothesize that this population may have a role in immunological control of HIV infection.IMPORTANCE HIV infection results in the establishment of a stable reservoir of latently infected cells; ART is usually required to keep viral replication under control and disease progression at bay, though a small subset of HIV-infected subjects can control HIV infection without ART through immunological mechanisms. In this study, we sought to identify subpopulations of NK cells that may be involved in the natural immunological control of HIV infection. We used mass cytometry to measure surface marker expression on peripheral NK cells. Using two distinct semisupervised machine learning approaches, we identified a CD11b+ CD57- CD161+ Siglec-7+ subpopulation of CD56dim CD16+ NK cells that differentiates HIV controllers from noncontrollers. These cells can be sorted out for future functional studies to assess their potential role in the immunological control of HIV infection.


Assuntos
Infecções por HIV/imunologia , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/virologia , Antígeno CD11b/imunologia , Antígeno CD56/imunologia , Antígenos CD57/imunologia , Linfócitos T CD8-Positivos/virologia , Linhagem Celular Tumoral , DNA Viral/imunologia , Infecções por HIV/virologia , HIV-1/imunologia , Humanos , Células K562 , Subfamília B de Receptores Semelhantes a Lectina de Células NK/imunologia , Receptores de IgG/imunologia , Viremia/imunologia , Viremia/virologia
15.
J Virol ; 93(9)2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30185599

RESUMO

Natural killer (NK) cells during chronic viral infection have been well studied in the past. We performed an unbiased next-generation RNA-sequencing approach to identify commonalities or differences of the effect of HIV, HCV, and HBV viremia on NK cell transcriptomes. Using cell sorting, we obtained CD3- CD56+ NK cells from blood of 6 HIV-, 8 HCV-, and 32 HBV-infected patients without treatment. After library preparation and sequencing, we used an in-house analytic pipeline to compare expression levels with matched healthy controls. In NK cells from HIV-, HCV-, and HBV-infected patients, transcriptome analysis identified 272, 53, and 56 differentially expressed genes, respectively (fold change, >1.5; q-value, 0.2). Interferon-stimulated genes were induced in NK cells from HIV/HCV patients, but not during HBV infection. HIV viremia downregulated ribosome assembly genes in NK cells. In HBV-infected patients, viral load and alanine aminotransferase (ALT) variation had little effect on genes related to NK effector function. In conclusion, we compare, for the first time, NK cell transcripts of viremic HIV, HCV, and HBV patients. We clearly demonstrate distinctive NK cell gene signatures in three different populations, suggestive for a different degree of functional alterations of the NK cell compartment compared to healthy individuals.IMPORTANCE Three viruses exist that can result in persistently high viral loads in immunocompetent humans: human immunodeficiency virus (HIV), hepatitis C virus, and hepatitis B virus. In the last decades, by using flow cytometry and in vitro assays on NK cells from patients with these types of infections, several impairments have been established, particularly during and possibly contributing to HIV viremia. However, the background of NK cell impairments in viremic patients is not well understood. In this study, we describe the NK cell transcriptomes of patients with high viral loads of different etiologies. We clearly demonstrate distinctive NK cell gene signatures with regard to interferon-stimulated gene induction and the expression of genes coding for activation markers or proteins involved in cytotoxic action, as well immunological genes. This study provides important details necessary to uncover the origin of functional and phenotypical differences between viremic patients and healthy subjects and provides many leads that can be confirmed using future in vitro manipulation experiments.


Assuntos
Perfilação da Expressão Gênica , Infecções por HIV/metabolismo , HIV-1/fisiologia , Hepacivirus/fisiologia , Vírus da Hepatite B/fisiologia , Hepatite B/metabolismo , Hepatite C/metabolismo , Células Matadoras Naturais/metabolismo , Replicação Viral , Adolescente , Adulto , Idoso , Feminino , Regulação da Expressão Gênica , Humanos , Células Matadoras Naturais/virologia , Masculino , Pessoa de Meia-Idade
16.
J Infect Dis ; 219(5): 723-733, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30252097

RESUMO

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of severe acute lower respiratory tract infections in infants. Natural killer (NK) cells are important antiviral effector cells that likely encounter RSV in the presence of virus-specific (maternal) antibodies. As NK cells potentially contribute to immunopathology, we investigated whether RSV affects their antiviral effector functions. METHODS: We assessed the phenotype and functionality of primary neonatal and adult NK cells by flow cytometry after stimulation with RSV or RSV-antibody complexes. RESULTS: We demonstrate for the first time that RSV infects neonatal and adult NK cells in vitro. Preincubation of virus with subneutralizing concentrations of RSV-specific antibodies significantly increased the percentage of infected NK cells. Upon infection, NK cells were significantly more prone to produce interferon-γ, while secretion of the cytotoxicity molecule perforin was not enhanced. CONCLUSIONS: Our findings suggest that (antibody-enhanced) RSV infection of NK cells induces a proinflammatory rather than a cytotoxic response, which may contribute to immunopathology. Considering that most RSV vaccines currently being developed aim at inducing (maternal) antibodies, these results highlight the importance of understanding the interactions between innate effector cells and virus-specific antibodies.


Assuntos
Interações Hospedeiro-Patógeno , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/virologia , Vírus Sincicial Respiratório Humano/crescimento & desenvolvimento , Adulto , Anticorpos Bloqueadores/imunologia , Anticorpos Antivirais/imunologia , Células Cultivadas , Voluntários Saudáveis , Humanos , Recém-Nascido , Interferons/metabolismo , Células Matadoras Naturais/metabolismo , Perforina/metabolismo , Infecções por Vírus Respiratório Sincicial
18.
J Virol ; 93(3)2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30404799

RESUMO

Current shock-and-kill strategies for the eradication of the HIV-1 reservoir have resulted in blips of viremia but not in a decrease in the size of the latent reservoir in patients on suppressive antiretroviral therapy (ART). This discrepancy could potentially be explained by an inability of the immune system to kill HIV-1-infected cells following the reversal of latency. Furthermore, some studies have suggested that certain latency-reversing agents (LRAs) may inhibit CD8+ T cell and natural killer (NK) cell responses. In this study, we tested the hypothesis that alpha interferon (IFN-α) could improve the function of NK cells from chronic progressors (CP) on ART. We show here that IFN-α treatment enhanced cytokine secretion, polyfunctionality, degranulation, and the cytotoxic potential of NK cells from healthy donors (HD) and CP. We also show that this cytokine enhanced the viral suppressive capacity of NK cells from HD and elite controllers or suppressors. Furthermore, IFN-α enhanced global CP CD8+ T cell cytokine responses and the suppressive capacity of ES CD8+ T cells. Our data suggest that IFN-α treatment may potentially be used as an immunomodulatory agent in HIV-1 cure strategies.IMPORTANCE Data suggest that HIV+ individuals unable to control infection fail to do so due to impaired cytokine production and/cytotoxic effector cell function. Consequently, the success of cure agendas such as the shock-and-kill strategy will probably depend on enhancing patient effector cell function. In this regard, NK cells are of particular interest since they complement the function of CD8+ T cells. Here, we demonstrate the ability of short-course alpha interferon (IFN-α) treatments to effectively enhance such effector functions in chronic progressor NK cells without inhibiting their general CD8+ T cell function. These results point to the possibility of exploring such short-course IFN-α treatments for the enhancement of effector cell function in HIV+ patients in future cure strategies.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Interferon-alfa/farmacologia , Células Matadoras Naturais/imunologia , Viremia/imunologia , Latência Viral/imunologia , Antivirais/farmacologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/virologia , Estudos de Casos e Controles , Degranulação Celular/efeitos dos fármacos , Citocinas/metabolismo , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Soropositividade para HIV , HIV-1/efeitos dos fármacos , Humanos , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/virologia , Ativação Linfocitária , Viremia/tratamento farmacológico , Viremia/virologia , Latência Viral/efeitos dos fármacos
19.
J Leukoc Biol ; 105(3): 589-602, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30575993

RESUMO

Salivary glands (SGs) represent a permissive site for several sialotropic viruses whose persistence is linked to the development of autoimmunity. Natural Killer (NK) cells play a key role in viral clearance but their involvement in viral infection control and in tertiary lymphoid structures (TLS) development within SGs is unknown. By using an inducible model of TLS in the SGs of wild-type C57BL/6 mice, induced by the local delivery of a replication-defective adenovirus (AdV), we demonstrated that circulating NK cells are rapidly recruited to SGs and highly enrich the early inflammatory infiltrate prior to TLS development. NK cells migrating to SGs in response to AdV infection up-regulate NKp46, undergo proliferation, acquire cytotoxic potential, produce Granzyme-B and IFN-γ, and reduce viral load in the acute phase of the infection. Nonetheless, the selective depletion of both circulating and infiltrating NK cells in AdV-infected mice neither affect the development and frequency of TLS nor the onset of autoimmunity. These data demonstrate that, upon local viral delivery of AdV, peripheral NK cells homing to SGs can exert an early control of the viral infection but are dispensable for the formation of TLS and breach of immunologic tolerance.


Assuntos
Adenoviridae/fisiologia , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/virologia , Linfócitos/patologia , Linfócitos/virologia , Glândulas Salivares/patologia , Glândulas Salivares/virologia , Animais , Proliferação de Células , Feminino , Imunidade Humoral , Camundongos Endogâmicos C57BL , Receptor 1 Desencadeador da Citotoxicidade Natural/metabolismo
20.
Dis Markers ; 2018: 1961058, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30581497

RESUMO

Background: Circulating Epstein-Barr virus (EBV) DNA concentrations were reported to have prognostic value for NK/T-cell lymphoma patients in limited small-scale studies. In this study, we aimed to evaluate the clinical utility of circulating EBV-DNA concentrations to a large sample of NK/T-cell lymphoma patients. Methods: We conducted this meta-analysis, which included a total of 15 prospective and retrospective comparable studies to assess the association between pretreatment EBV-DNA (pre-DNA), posttreatment EBV-DNA (post-DNA), and clinical outcomes of NK/T-cell lymphoma patients. We chose overall survival (OS) as the primary endpoint and progression-free survival (PFS), complete response (CR), and overall response rate (ORR) as secondary endpoints. Results: High pre-DNA and detectable post-DNA were both significantly correlated with poorer OS in NK/T-cell lymphoma patients (P < 0.05), with hazard radios (HRs) equal to 3.45 and 2.30, respectively. High pre-DNA and detectable post-DNA also predicted poorer PFS. Additionally, high pre-DNA was found to be significantly correlated with both worse CR and ORR, which indicated worse treatment response. Conclusion: Circulating EBV-DNA concentrations provides prognostic values of survival and treatment response in NK/T-cell lymphoma patients.


Assuntos
DNA Viral/sangue , Herpesvirus Humano 4/genética , Linfoma de Células T/mortalidade , Linfoma de Células T/virologia , Intervalo Livre de Doença , Infecções por Vírus Epstein-Barr/complicações , Humanos , Células Matadoras Naturais/virologia , Linfoma de Células T/terapia , Prognóstico , Resultado do Tratamento
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