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1.
Blood ; 116(20): 4158-67, 2010 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-20671122

RESUMO

To investigate human natural killer (NK)-cell reactivity in vivo we have reconstituted human immune system components by transplantation of human hematopoietic progenitor cells into NOD-scid IL2Rγ(null) mice. We demonstrate here that this model allows the development of all NK-cell subsets that are also found in human adult peripheral and cord blood, including NKp46(+)CD56(-) NK cells. Similar to human cord blood, NK cells from these reconstituted mice require preactivation by interleukin-15 to reach the functional competence of human adult NK cells. Mainly the terminally differentiated CD16(+) NK cells demonstrate lower reactivity without this stimulation. After preactivation, both CD16(+) and CD16(-) NK cells efficiently produce interferon-γ and degranulate in response to stimulation with NK cell-susceptible targets, including K562 erythroleukemia cells. NK-cell lines, established from reconstituted mice, demonstrate cytotoxicity against this tumor cell line. Importantly, preactivation can as well be achieved by bystander cell maturation via poly I:C stimulation in vitro and injection of this maturation stimulus in vivo. Preactivation in vivo enhances killing of human leukocyte antigen class I negative tumor cells after their adoptive transfer. These data suggest that a functional, but resting, NK-cell compartment can be established in immune-compromised mice after human hematopoietic progenitor cell transfer.


Assuntos
Sistema Imunitário/imunologia , Imunocompetência/imunologia , Células Matadoras Naturais/imunologia , Ativação Linfocitária/imunologia , Adulto , Animais , Antígenos CD34/metabolismo , Antígeno CD56/metabolismo , Degranulação Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Citotoxicidade Imunológica/efeitos dos fármacos , Sangue Fetal/citologia , Granzimas/metabolismo , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/imunologia , Humanos , Sistema Imunitário/efeitos dos fármacos , Imunocompetência/efeitos dos fármacos , Interferon gama/biossíntese , Interleucina-15/farmacologia , Células Matadoras Naturais/citologia , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/fisiologia , Ativação Linfocitária/efeitos dos fármacos , Subpopulações de Linfócitos/citologia , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/imunologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Receptor 1 Desencadeador da Citotoxicidade Natural/metabolismo , Perforina/metabolismo , Poli I-C/administração & dosagem , Poli I-C/farmacologia , Receptores de Interleucina-2/metabolismo
2.
J Clin Invest ; 117(11): 3316-29, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17948125

RESUMO

DCs activate NK cells during innate immune responses to viral infections. However, the composition and kinetics of the immunological synapse mediating this interaction are largely unknown. Here, we report the rapid formation of an immunological synapse between human resting NK cells and mature DCs. Although inhibitory NK cell receptors were polarized to this synapse, where they are known to protect mature DCs from NK cell lysis, the NK cell also received activation signals that induced mobilization of intracellular calcium and CD69 upregulation. The high-affinity component of the receptor for IL-15, IL-15Ralpha, accumulated at the synapse center on NK cells, and blocking of IL-15Ralpha increased NK cell apoptosis and diminished NK cell survival during their interaction with DCs. Furthermore, IL-15Ralpha-deficient NK cells, obtained from donors with a history of infectious mononucleosis, showed diminished survival in culture with DCs. Synapse formation was required for IL-15Ralpha-mediated NK cell survival, because synapse disruption by adhesion molecule blocking decreased DC-induced NK cell survival. These results identify what we believe to be a novel regulatory NK cell synapse with hallmarks of spatially separated inhibitory and activating interactions at its center. We suggest that this synapse formation enables optimal NK cell activation by DCs during innate immune responses.


Assuntos
Comunicação Celular/fisiologia , Sobrevivência Celular , Células Dendríticas/fisiologia , Subunidade alfa de Receptor de Interleucina-15/metabolismo , Células Matadoras Naturais/fisiologia , Subpopulações de Linfócitos , Animais , Antígenos CD/imunologia , Apoptose/fisiologia , Biomarcadores/metabolismo , Células Cultivadas , Técnicas de Cocultura , Células Dendríticas/citologia , Humanos , Imunidade Inata/fisiologia , Subunidade alfa de Receptor de Interleucina-15/genética , Células Matadoras Naturais/citologia , Ativação Linfocitária
3.
PLoS Pathog ; 4(2): e27, 2008 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-18266470

RESUMO

Cells of the innate immune system act in synergy to provide a first line of defense against pathogens. Here we describe that dendritic cells (DCs), matured with viral products or mimics thereof, including Epstein-Barr virus (EBV), activated natural killer (NK) cells more efficiently than other mature DC preparations. CD56(bright)CD16(-) NK cells, which are enriched in human secondary lymphoid tissues, responded primarily to this DC activation. DCs elicited 50-fold stronger interferon-gamma (IFN-gamma) secretion from tonsilar NK cells than from peripheral blood NK cells, reaching levels that inhibited B cell transformation by EBV. In fact, 100- to 1,000-fold less tonsilar than peripheral blood NK cells were required to achieve the same protection in vitro, indicating that innate immune control of EBV by NK cells is most efficient at this primary site of EBV infection. The high IFN-gamma concentrations, produced by tonsilar NK cells, delayed latent EBV antigen expression, resulting in decreased B cell proliferation during the first week after EBV infection in vitro. These results suggest that NK cell activation by DCs can limit primary EBV infection in tonsils until adaptive immunity establishes immune control of this persistent and oncogenic human pathogen.


Assuntos
Linfócitos B/imunologia , Células Dendríticas/imunologia , Herpesvirus Humano 4/fisiologia , Interferon gama/metabolismo , Células Matadoras Naturais/imunologia , Ativação Linfocitária/imunologia , Tonsila Palatina/citologia , Antígenos de Diferenciação de Linfócitos T/imunologia , Linfócitos B/virologia , Antígeno CD56/metabolismo , Células Dendríticas/virologia , Humanos , Células Matadoras Naturais/virologia , Linfonodos/imunologia , Linfonodos/metabolismo , Receptores de IgG/metabolismo , Baço/imunologia , Baço/metabolismo
4.
Blood ; 112(4): 1231-9, 2008 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-18519810

RESUMO

Dendritic cells (DCs) express many endocytic receptors that deliver antigens for major histocompatibility class (MHC) I and II presentation to CD8(+) and CD4(+) T cells, respectively. Here, we show that targeting Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) to one of them, the human multilectin DEC-205 receptor, in the presence of the DC maturation stimulus poly(I:C), expanded EBNA1-specific CD4(+) and CD8(+) memory T cells, and these lymphocytes could control the outgrowth of autologous EBV-infected B cells in vitro. In addition, using a novel mouse model with reconstituted human immune system components, we demonstrated that vaccination with alphaDEC-205-EBNA1 antibodies primed EBNA1-specific IFN-gamma-secreting T cells and also induced anti-EBNA1 antibodies in a subset of immunized mice. Because EBNA1 is the one EBV antigen that is expressed in all proliferating cells infected with this virus, our data suggest that DEC-205 targeting should be explored as a vaccination approach against symptomatic primary EBV infection and against EBV-associated malignancies.


Assuntos
Antígenos CD/imunologia , Proliferação de Células , Antígenos Nucleares do Vírus Epstein-Barr/imunologia , Herpesvirus Humano 4/imunologia , Lectinas Tipo C/imunologia , Ativação Linfocitária , Receptores de Superfície Celular/imunologia , Linfócitos T/imunologia , Animais , Anticorpos Antivirais , Linfócitos B/virologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/imunologia , Humanos , Memória Imunológica , Camundongos , Camundongos Transgênicos , Antígenos de Histocompatibilidade Menor , Vacinação
5.
Front Immunol ; 10: 89, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30766535

RESUMO

Human immune system mice are highly valuable for in vivo dissection of human immune responses. Although they were employed for analyzing tuberculosis (TB) disease, there is little data on the spatial organization and cellular composition of human immune cells in TB granuloma pathology in this model. We demonstrate that human immune system mice, generated by transplanted human fetal liver derived hematopoietic stem cells develop a continuum of pulmonary lesions upon Mycobacterium tuberculosis aerosol infection. In particular, caseous necrotic granulomas, which contribute to prolonged TB treatment time, developed, and had cellular phenotypic spatial-organization similar to TB patients. By comparing two recommended drug regimens, we confirmed observations made in clinical settings: Adding Moxifloxacin to a classical chemotherapy regimen had no beneficial effects on bacterial eradication. We consider this model instrumental for deeper understanding of human specific features of TB pathogenesis and of particular value for the pre-clinical drug development pipeline.


Assuntos
Antituberculosos/uso terapêutico , Granuloma/tratamento farmacológico , Pulmão/imunologia , Mycobacterium tuberculosis/fisiologia , Tuberculose Pulmonar/tratamento farmacológico , Animais , Modelos Animais de Doenças , Quimioterapia Combinada , Feminino , Granuloma/patologia , Transplante de Células-Tronco Hematopoéticas , Humanos , Pulmão/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Moxifloxacina/uso terapêutico , Tuberculose Pulmonar/patologia
6.
Int J Cancer ; 123(12): 2824-31, 2008 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-18781564

RESUMO

Epstein Barr virus (EBV) causes lymphomas in immune competent and, at increased frequencies, in immune compromised patients. In the presence of an intact immune system, EBV-associated lymphomas express in most cases only 3 or fewer EBV antigens at the protein level, always including the nuclear antigen 1 of EBV (EBNA1). EBNA1 is a prominent target for EBV-specific CD4(+) T cell and humoral immune responses in healthy EBV carriers. Here we demonstrate that patients with EBV-associated lymphomas, primarily Hodgkin's lymphoma, lack detectable EBNA1-specific CD4(+) T-cell responses and have slightly altered EBNA1-specific antibody titers at diagnosis. In contrast, the majority of EBV-negative lymphoma patients had detectable IFN-gamma expression and proliferation by CD4(+) T cells in response to EBNA1, and carry EBNA1-specific immunoglobulins at levels similar to healthy virus carriers. Other EBV antigens, which were not present in the tumors, were recognized in less EBV positive, than negative lymphoma patients, but detectable responses reached similar CD8(+) T cell frequencies in both cohorts. Patients with EBV-positive and -negative lymphomas did not differ in T-cell responses in influenza-specific CD4(+) T cell proliferation and in antibody titers against tetanus toxoid. These data suggest a selective loss of EBNA1-specific immune control in EBV-associated lymphoma patients, which should be targeted for immunotherapy of these malignancies.


Assuntos
Antígenos Virais/imunologia , Linfócitos T CD4-Positivos/imunologia , Proteínas de Transporte/imunologia , Herpesvirus Humano 4/imunologia , Linfoma/imunologia , Linfoma/virologia , Adolescente , Adulto , Idoso , Antígenos Nucleares/imunologia , Proliferação de Células , Criança , Citocinas/análise , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Hibridização In Situ , Interferon gama/imunologia , Masculino , Pessoa de Meia-Idade , Proteínas de Ligação a RNA , Adulto Jovem
7.
J Clin Invest ; 124(3): 1268-82, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24509076

RESUMO

Successful host defense against numerous pulmonary infections depends on bacterial clearance by polymorphonuclear leukocytes (PMNs); however, excessive PMN accumulation can result in life-threatening lung injury. Local expression of CXC chemokines is critical for PMN recruitment. The impact of chemokine-dependent PMN recruitment during pulmonary Mycobacterium tuberculosis infection is not fully understood. Here, we analyzed expression of genes encoding CXC chemokines in M. tuberculosis-infected murine lung tissue and found that M. tuberculosis infection promotes upregulation of Cxcr2 and its ligand Cxcl5. To determine the contribution of CXCL5 in pulmonary PMN recruitment, we generated Cxcl5(-/-) mice and analyzed their immune response against M. tuberculosis. Both Cxcr2(-/-) mice and Cxcl5(-/-) mice, which are deficient for only one of numerous CXCR2 ligands, exhibited enhanced survival compared with that of WT mice following high-dose M. tuberculosis infection. The resistance of Cxcl5(-/-) mice to M. tuberculosis infection was not due to heightened M. tuberculosis clearance but was the result of impaired PMN recruitment, which reduced pulmonary inflammation. Lung epithelial cells were the main source of CXCL5 upon M. tuberculosis infection, and secretion of CXCL5 was reduced by blocking TLR2 signaling. Together, our data indicate that TLR2-induced epithelial-derived CXCL5 is critical for PMN-driven destructive inflammation in pulmonary tuberculosis.


Assuntos
Células Epiteliais Alveolares/imunologia , Quimiocina CXCL5/fisiologia , Mycobacterium tuberculosis/imunologia , Neutrófilos/imunologia , Tuberculose Pulmonar/imunologia , Células Epiteliais Alveolares/metabolismo , Células Epiteliais Alveolares/microbiologia , Animais , Linhagem Celular , Inflamação/metabolismo , Inflamação/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infiltração de Neutrófilos , Neutrófilos/microbiologia , Receptores de Interleucina-8B/metabolismo , Linfócitos T/imunologia , Linfócitos T/microbiologia , Receptor 2 Toll-Like/metabolismo , Ativação Transcricional , Tuberculose Pulmonar/metabolismo , Tuberculose Pulmonar/patologia
8.
Cell Host Microbe ; 6(4): 367-80, 2009 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-19837376

RESUMO

Influenza A virus is an important human pathogen causing significant morbidity and mortality every year and threatening the human population with epidemics and pandemics. Therefore, it is important to understand the biology of this virus to develop strategies to control its pathogenicity. Here, we demonstrate that influenza A virus inhibits macroautophagy, a cellular process known to be manipulated by diverse pathogens. Influenza A virus infection causes accumulation of autophagosomes by blocking their fusion with lysosomes, and one viral protein, matrix protein 2, is necessary and sufficient for this inhibition of autophagosome degradation. Macroautophagy inhibition by matrix protein 2 compromises survival of influenza virus-infected cells but does not influence viral replication. We propose that influenza A virus, which also encodes proapoptotic proteins, is able to determine the death of its host cell by inducing apoptosis and also by blocking macroautophagy.


Assuntos
Apoptose , Autofagia , Vírus da Influenza A/patogenicidade , Lisossomos/metabolismo , Fagossomos/metabolismo , Proteínas da Matriz Viral/fisiologia , Fatores de Virulência/fisiologia , Animais , Linhagem Celular , Cães , Células Epiteliais/virologia , Humanos , Lisossomos/ultraestrutura , Camundongos , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Fagossomos/ultraestrutura
9.
J Exp Med ; 206(6): 1423-34, 2009 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-19487422

RESUMO

Many pathogens that cause human disease infect only humans. To identify the mechanisms of immune protection against these pathogens and also to evaluate promising vaccine candidates, a small animal model would be desirable. We demonstrate that primary T cell responses in mice with reconstituted human immune system components control infection with the oncogenic and persistent Epstein-Barr virus (EBV). These cytotoxic and interferon-gamma-producing T cell responses were human leukocyte antigen (HLA) restricted and specific for EBV-derived peptides. In HLA-A2 transgenic animals and similar to human EBV carriers, T cell responses against lytic EBV antigens dominated over recognition of latent EBV antigens. T cell depletion resulted in elevated viral loads and emergence of EBV-associated lymphoproliferative disease. Both loss of CD4(+) and CD8(+) T cells abolished immune control. Therefore, this mouse model recapitulates features of symptomatic primary EBV infection and generates T cell-mediated immune control that resists oncogenic transformation.


Assuntos
Infecções por Vírus Epstein-Barr/imunologia , Herpesvirus Humano 4/imunologia , Sistema Imunitário/imunologia , Neoplasias , Linfócitos T/imunologia , Animais , Modelos Animais de Doenças , Antígeno HLA-A2/imunologia , Humanos , Rim/citologia , Rim/imunologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Camundongos Transgênicos , Neoplasias/imunologia , Neoplasias/virologia , Baço/citologia , Baço/imunologia , Linfócitos T/citologia
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