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1.
Mem Inst Oswaldo Cruz ; 114: e190102, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31411311

RESUMO

BACKGROUND: Once in the pulmonary alveoli, Mycobacterium tuberculosis (Mtb) enters into contact with alveolar macrophages and dendritic cells (DCs). DCs represent the link between the innate and adaptive immune system owing to their capacity to be both a sentinel and an orchestrator of the antigen-specific immune responses against Mtb. The effect that the virulence of Mtb has on the interaction between the bacilli and human DCs has not been fully explored. OBJECTIVE: To evaluate the effect of Mtb virulence on human monocyte-derived DCs. METHODS: We exposed human monocyte-derived DCs to Mtb clinical strains (isolated from an epidemiological Mtb diversity study in Mexico) bearing different degrees of virulence and evaluated the capacity of DCs to internalise the bacilli, control intracellular growth, engage cell death pathways, express markers for activation and antigen presentation, and expand to stimulate autologous CD4+ T cells proliferation. FINDINGS: In the case of the hypervirulent Mtb strain (Phenotype 1, strain 9005186, lineage 3), we report that DCs internalise and neutralise intracellular growth of the bacilli, undergo low rates of apoptosis, and contribute poorly to T-cell expansion, as compared to the H37Rv reference strain. In the case of the hypovirulent Mtb strain (Phenotype 4, strain 9985449, lineage 4), although DCs internalise and preclude proliferation of the bacilli, the DCs also display a high level of apoptosis, massive levels of apoptosis that prevent them from maintaining autologous CD4+ T cells in a co-culture system, as compared to H37Rv. MAIN CONCLUSIONS: Our findings suggest that variability in virulence among Mtb clinical strains affects the capacity of DCs to respond to pathogenic challenge and mount an immune response against it, highlighting important parallels to studies previously done in mouse models.


Assuntos
Células Dendríticas/virologia , Ativação Linfocitária , Mycobacterium tuberculosis/patogenicidade , Linfócitos T Reguladores/parasitologia , Animais , Humanos , Camundongos , Transdução de Sinais , Virulência
2.
Nat Commun ; 10(1): 2759, 2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227717

RESUMO

Langerhans cells (LC) are thought to be the only mononuclear phagocyte population in the epidermis where they detect pathogens. Here, we show that CD11c+ dendritic cells (DCs) are also present. These cells are transcriptionally similar to dermal cDC2 but are more efficient antigen-presenting cells. Compared to LCs, epidermal CD11c+ DCs are enriched in anogenital tissues where they preferentially interact with HIV, express the higher levels of HIV entry receptor CCR5, support the higher levels of HIV uptake and replication and are more efficient at transmitting the virus to CD4 T cells. Importantly, these findings are observed using both a lab-adapted and transmitted/founder strain of HIV. We also describe a CD33low cell population, which is transcriptionally similar to LCs but does not appear to function as antigen-presenting cells or acts as HIV target cells. Our findings reveal that epidermal DCs in anogenital tissues potentially play a key role in sexual transmission of HIV.


Assuntos
Células Dendríticas/virologia , Células Epidérmicas/virologia , Infecções por HIV/transmissão , HIV-1/imunologia , Apresentação do Antígeno/imunologia , Antígeno CD11c/metabolismo , Células Cultivadas , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Células Epidérmicas/imunologia , Células Epidérmicas/metabolismo , Epiderme/imunologia , Feminino , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/patogenicidade , Voluntários Saudáveis , Humanos , Masculino , Cultura Primária de Células , Receptores CCR5/metabolismo , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Linfócitos T/imunologia , Internalização do Vírus
3.
Virus Res ; 265: 20-29, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30831176

RESUMO

Red bone marrow is physiologically unique in that it is both the major hematopoietic organ and a primary lymphoid organ. Porcine reproductive and respiratory syndrome virus (PRRSV) affects normal bone marrow functions. The cumulative effect of PRRSV infection is acute bone marrow failure, i.e., hypoplasia characterized by the absence of normal myeloid and erythroid precursors and increased red bone marrow M:E ratios. The measurable clinical consequence of PRRSV infection on normal red bone marrow functions is a reduction in the number of cells emigrating to the peripheral blood resulting in leucopenia, anemia, and thrombocytopenia. These observations may be explained by the fact that bone marrow-derived mononuclear cells, i.e., imDCs, mDCs, monocytes, macrophages, and myeloid precursor cells are susceptible to PRRSV. Apoptosis in bone marrow-derived cells occurs both as a direct consequence of infection and indirectly via a bystander effect. Immunologically, PRRSV-susceptible mononuclear cells are the first line of defense against microbial infection and responsible for antigen recognition, processing, and presentation to T and B cells; a critical step in the initiation and development of an effective adaptive immune. Thus, impairment of normal immune function renders the host less able to resist and/or eliminate secondary infectious agents and partially explains the synergy between PRRSV and bacterial and viral co-infections.


Assuntos
Células da Medula Óssea/virologia , Medula Óssea/patologia , Medula Óssea/virologia , Síndrome Respiratória e Reprodutiva Suína/patologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/patogenicidade , Animais , Apresentação do Antígeno , Apoptose , Células da Medula Óssea/patologia , Células Dendríticas/imunologia , Células Dendríticas/virologia , Macrófagos/imunologia , Macrófagos/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/isolamento & purificação , Suínos
4.
Nat Immunol ; 20(5): 593-601, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30886417

RESUMO

Interferon-λ (IFN-λ) acts on mucosal epithelial cells and thereby confers direct antiviral protection. In contrast, the role of IFN-λ in adaptive immunity is far less clear. Here, we report that mice deficient in IFN-λ signaling exhibited impaired CD8+ T cell and antibody responses after infection with a live-attenuated influenza virus. Virus-induced release of IFN-λ triggered the synthesis of thymic stromal lymphopoietin (TSLP) by M cells in the upper airways that, in turn, stimulated migratory dendritic cells and boosted antigen-dependent germinal center reactions in draining lymph nodes. The IFN-λ-TSLP axis also boosted production of the immunoglobulins IgG1 and IgA after intranasal immunization with influenza virus subunit vaccines and improved survival of mice after challenge with virulent influenza viruses. IFN-λ did not influence the efficacy of vaccines applied by subcutaneous or intraperitoneal routes, indicating that IFN-λ plays a vital role in potentiating adaptive immune responses that initiate at mucosal surfaces.


Assuntos
Imunidade Adaptativa/imunologia , Citocinas/imunologia , Imunidade nas Mucosas/imunologia , Interleucinas/imunologia , Imunidade Adaptativa/efeitos dos fármacos , Imunidade Adaptativa/genética , Animais , Formação de Anticorpos/efeitos dos fármacos , Formação de Anticorpos/imunologia , Células Cultivadas , Citocinas/genética , Citocinas/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/virologia , Imunidade nas Mucosas/efeitos dos fármacos , Imunidade nas Mucosas/genética , Imunização/métodos , Vírus da Influenza A/efeitos dos fármacos , Vírus da Influenza A/imunologia , Vírus da Influenza A/fisiologia , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/imunologia , Interleucinas/administração & dosagem , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/virologia , Receptores de Interferon/genética , Receptores de Interferon/imunologia , Receptores de Interferon/metabolismo
5.
Artigo em Inglês | MEDLINE | ID: mdl-30746342

RESUMO

Several mosquito-borne Flaviviruses such as Japanese encephalitis virus (JEV), West Nile virus (WNV), Dengue Virus (DENV), and Zika virus (ZIKV) can cause severe clinical disease. Being zoonotic, Flaviviruses infect a wide variety of terrestrial vertebrates, which dependent of the virus-host interactions, can enhance ongoing epidemics and maintain the virus in the environment for prolonged periods. Targeted species can vary from amphibians, birds to various mammals, dependent on the virus. For many mosquito-borne flaviviruses the spectrum of targeted species is incompletely understood, in particular with respect to their contribution to the maintenance of virus in certain geographical regions. Furthermore, little is known about virus and host factors contributing to species tropism. The present study utilized human and porcine monocyte-derived dendritic cells (MoDC) as a cell culture model to better understand Flavivirus species tropism and innate immune responses. MoDC were selected based on their presence in the skin and their role as an early target cell for several Flaviviruses and their role as immune sentinels. While differences in viral infectivity and replication were minor when comparing porcine with human MoDC for some of the tested Flaviviruses, a particularly strong replication in human MoDC was found with USUV, while JEV appeared to have a stronger tropism for porcine MoDC. With respect to innate immune responses we found high induction of TNF and IFN-ß in both human and porcine MoDC after infection with JEV, WNV, and USUV, but not with DENV, ZIKV, and Wesselsbron virus. Spondweni virus induced these cytokine responses only in porcine MoDC. Overall, innate immune responses correlated with early infectivity and cytokine production. In conclusion, we demonstrate Flavivirus-dependent differences in the interaction with MoDC. These may play a role in pathogenesis but appear to only partially reflect the expected species tropism.


Assuntos
Células Dendríticas/virologia , Flavivirus/crescimento & desenvolvimento , Flavivirus/isolamento & purificação , Especificidade de Hospedeiro , Mosquitos Vetores/virologia , Animais , Células Cultivadas , Células Dendríticas/imunologia , Humanos , Imunidade Inata , Suínos
6.
Viruses ; 11(2)2019 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-30744065

RESUMO

Dendritic cells (DCs) express Fcγ receptors (FcγRs) for the binding immune complexes (ICs) consisting of IgG and antigens (Ags). IC⁻FcγR interactions have been demonstrated to enhance activation and antigen-presenting functions of DCs. Utilizing Friend virus (FV), an oncogenic mouse retrovirus, we investigated the effect of IgG-opsonization of retroviral particles on the infection of DCs and the subsequent presentation of viral antigens by DCs to virus-specific CD8 T cells. We found that opsonization by virus-specific non-neutralizing IgG abrogated DC infection and as a consequence significantly reduced the capacity of DCs to activate virus-specific CD8 T cells. Effects of IgG-opsonization were mediated by the high-affinity FcγR type I, CD64, expressed on DCs. Our results suggest that different opsonization patterns on the retroviral surface modulate infection and antigen-presenting functions of DCs, whereby, in contrast to complement, IgG reduces the capacity of DCs to activate cytotoxic T cell (CTL) responses.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/imunologia , Vírus da Leucemia Murina de Friend/imunologia , Ativação Linfocitária , Receptores de IgG/imunologia , Animais , Apresentação do Antígeno , Complexo Antígeno-Anticorpo/imunologia , Células Dendríticas/virologia , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Receptores de IgG/genética
7.
Cell Host Microbe ; 25(1): 87-100.e10, 2019 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-30595553

RESUMO

Lymph- and blood-borne retroviruses exploit CD169/Siglec-1-mediated capture by subcapsular sinus and marginal zone metallophilic macrophages for trans-infection of permissive lymphocytes. However, the impact of CD169-mediated virus capture on retrovirus dissemination and pathogenesis in vivo is unknown. In a murine model of the splenomegaly-inducing retrovirus Friend virus complex (FVC) infection, we find that while CD169 promoted draining lymph node infection, it limited systemic spread to the spleen. At the spleen, CD169-expressing macrophages captured incoming blood-borne retroviruses and limited their spread to the erythroblasts in the red pulp where FVC manifests its pathogenesis. CD169-mediated retroviral capture activated conventional dendritic cells 1 (cDC1s) and promoted cytotoxic CD8+ T cell responses, resulting in efficient clearing of FVC-infected cells. Accordingly, CD169 blockade led to higher viral loads and accelerated death in susceptible mouse strains. Thus, CD169 plays a protective role during FVC pathogenesis by reducing viral dissemination to erythroblasts and eliciting an effective cytotoxic T lymphocyte response via cDC1s.


Assuntos
Lectinas/farmacologia , Substâncias Protetoras/farmacologia , Infecções por Retroviridae/tratamento farmacológico , Retroviridae/efeitos dos fármacos , Retroviridae/patogenicidade , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/farmacologia , Animais , Linfócitos T CD8-Positivos , Proliferação de Células , Células Dendríticas/virologia , Modelos Animais de Doenças , Eritroblastos/virologia , Feminino , Interferon Tipo I/metabolismo , Linfonodos/virologia , Macrófagos/efeitos dos fármacos , Macrófagos/virologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Baço , Linfócitos T Citotóxicos , Carga Viral
8.
Nat Commun ; 10(1): 361, 2019 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-30664644

RESUMO

Intestinal and free-living protozoa, such as Giardia lamblia, express a dense coat of variant-specific surface proteins (VSPs) on trophozoites that protects the parasite inside the host's intestine. Here we show that VSPs not only are resistant to proteolytic digestion and extreme pH and temperatures but also stimulate host innate immune responses in a TLR-4 dependent manner. We show that these properties can be exploited to both protect and adjuvant vaccine antigens for oral administration. Chimeric Virus-like Particles (VLPs) decorated with VSPs and expressing model surface antigens, such as influenza virus hemagglutinin (HA) and neuraminidase (NA), are protected from degradation and activate antigen presenting cells in vitro. Orally administered VSP-pseudotyped VLPs, but not plain VLPs, generate robust immune responses that protect mice from influenza infection and HA-expressing tumors. This versatile vaccine platform has the attributes to meet the ultimate challenge of generating safe, stable and efficient oral vaccines.


Assuntos
Giardia lamblia/química , Vacinas contra Influenza/imunologia , Proteínas de Membrana/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Proteínas de Protozoários/imunologia , Vacinas de Partículas Semelhantes a Vírus/imunologia , Adjuvantes Imunológicos , Administração Oral , Animais , Apresentação do Antígeno/efeitos dos fármacos , Bioengenharia/métodos , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/virologia , Feminino , Expressão Gênica , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Humanos , Imunidade Inata/efeitos dos fármacos , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/genética , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Transgênicos , Neuraminidase/genética , Neuraminidase/imunologia , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Estabilidade Proteica , Proteínas de Protozoários/genética , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Trofozoítos/química , Vacinação , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Vacinas de Partículas Semelhantes a Vírus/genética
9.
Viruses ; 11(1)2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30650519

RESUMO

Respiratory syncytial virus (RSV) is a major cause of respiratory infectious disease in infants and young children. Dendritic cells (DCs) and macrophages (MACs) are known to play important roles in RSV recognition, and in the production of type I interferons (IFNs) and pro-inflammatory cytokine in RSV infection. Toll-like receptor 7 (TLR7), myeloid differentiation primary response 88 (MyD88), and mitochondrial antiviral-signaling protein (MAVS) are known to be important for the RSV sensing pathway in DCs and MACs. However, despite the critical roles of type I IFNs in the anti-RSV immune response, the pattern recognition receptors (PRRs) that are required for RSV sensing in DCs and MACs remain unclear. Here, we investigate the pathway activated by RSV A2 strain infection using an IFN-ß/YFP reporter mouse model to visualize IFN-ß-producing cells and in vitro RSV infection in bone marrow-derived DCs (BM-DCs) and macrophages (BM-DMs). We present our finding that MyD88, but not TLR7, are important for RSV recognition and type I IFN and pro-inflammatory production in DCs and MACs. MAVS-deficient BM-DCs and BM-DMs show impaired induction of IFN-ß production upon RSV stimulation, and this effect is RSV replication-dependent. Our study provides information on cell type-specific PRR requirements in innate immune responses against RSV infection.


Assuntos
Células Dendríticas/imunologia , Imunidade Inata , Interferon beta/imunologia , Macrófagos/imunologia , Vírus Sincicial Respiratório Humano/imunologia , Transdução de Sinais , Animais , Células Cultivadas , Células Dendríticas/virologia , Macrófagos/virologia , Glicoproteínas de Membrana/imunologia , Camundongos , Fator 88 de Diferenciação Mieloide/imunologia , Receptores de Reconhecimento de Padrão , Receptor 7 Toll-Like/imunologia , Replicação Viral
10.
Virology ; 529: 65-72, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30665099

RESUMO

Porcine reproductive and respiratory syndrome virus (PRRSV) infects monocyte-derived DCs, and previous reports have shown that PRRSV does not infect conventional DCs (cDCs) in vitro, but the effects on cDCs from lymphoid tissues are unknown. This study analyzed the response and susceptibility of tonsil DEC205+cDCs from infected pigs. We confirmed the phenotype and lineage of bona fide tonsil cDCs with the mRNA expression of FLT3+ and the phenotype MHCII+CADM1highDEC205+ (DEC205+cDCs). These cells were not infected by PRRSV, whereas CD163+ tonsil cells were infected. The numbers of tonsil cDCs and CD163+ cells were not affected by PRRSV, in contrast to the reduction in alveolar macrophage numbers. DEC205+cDCs exhibited an increase in the expression of IL-12 at 5 days postinfection, suggesting a proinflammatory response by these cells to the virus. In summary, this study confirms that, in vitro and in vivo, cDCs are not susceptible to PRRSV but can respond against it.


Assuntos
Células Dendríticas/virologia , Tonsila Palatina/citologia , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/fisiologia , Animais , Antígenos CD/genética , Antígenos CD/metabolismo , Molécula 1 de Adesão Celular/genética , Molécula 1 de Adesão Celular/metabolismo , Regulação da Expressão Gênica/imunologia , Interleucina-12/genética , Interleucina-12/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Complexo Principal de Histocompatibilidade , Antígenos de Histocompatibilidade Menor/genética , Antígenos de Histocompatibilidade Menor/metabolismo , Síndrome Respiratória e Reprodutiva Suína/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Suínos , Tirosina Quinase 3 Semelhante a fms/genética , Tirosina Quinase 3 Semelhante a fms/metabolismo
11.
Vet Microbiol ; 228: 134-142, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30593359

RESUMO

Dendritic cells (DCs) are potent antigen-presenting cells (APCs) that play an important role in inducing primary antigen-specific immune responses. Some viruses have evolved to specifically target DCs to circumvent the host immune responses for their persistence in the host. One example is porcine reproductive and respiratory syndrome virus (PRRSV) that causes a persistent infection in pigs through modulating DC-mediated antiviral response. To study the cellular protein responses in PRRSV-infected monocyte-derived dendritic cells (MoDCs), two-dimensional liquid chromatography-tandem mass spectrometry coupled with isobaric tags for relative and absolute quantification (iTRAQ) labeling was employed to quantitatively identify the differentially expressed proteins in PRRSV-infected MoDCs and the control cells. A total of 252 cellular proteins in MoDCs that were significantly altered at different time periods post-infection were identified. Differentially expressed proteins that are involved in the endocytosis pathway, actin cytoskeleton network, antigen processing and presentation, JAK-STAT signaling pathway and PRRSV receptors were identified and further analyzed. Among them, the expression changes of STAT1, Mx1, PICALM and SLA-DR were further verified by Western blotting. The protein profiles associated with PRRSV infection of MoDCs should offer novel insights to further investigation of PRRSV-mediated antiviral evasion mechanism and its pathobiology in swine.


Assuntos
Biologia Computacional , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Proteoma , Animais , Cromatografia Líquida/veterinária , Células Dendríticas/metabolismo , Células Dendríticas/virologia , Monócitos/metabolismo , Monócitos/virologia , Proteômica , Suínos , Espectrometria de Massas em Tandem/veterinária , Replicação Viral
12.
J Immunol ; 202(3): 816-826, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30593540

RESUMO

HIV coinfection is the greatest risk factor for transition of latent Mycobacterium tuberculosis infection into active tuberculosis (TB). Epidemiological data reveal both the reduction and the impairment of M. tuberculosis-specific CD4 T cells, although the cellular link and actual mechanisms resulting in immune impairment/suppression need further characterization. M. tuberculosis-specific CD4 T cells play a central role in development of protective immunity against TB, in which they participate in the activation of macrophages through the dendritic cell (DC)-T cell axis. Using an in vitro priming system for generating Ag-specific T cells, we explored if HIV-M. tuberculosis-infected (coinfected) human DCs can dysregulate the M. tuberculosis-specific CD4 T cell phenotype and functionality and subsequently mediate the failure to control M. tuberculosis infection in macrophages. After coculture with coinfected DCs, M. tuberculosis Ag-specific CD4 T cells lost their ability to enhance control of M. tuberculosis infection in infected macrophages. Coinfection of DCs reduced proliferation of M. tuberculosis Ag-specific CD4 T cells without affecting their viability, led to increased expression of coinhibitory factors CTLA-4, PD-1, and Blimp-1, and decreased expression of costimulatory molecules CD40L, CD28, and ICOS on the T cells. Expression of the regulatory T cell markers FOXP3 and CD25, together with the immunosuppressive cytokines TGF-ß and IL-10, was also significantly increased by coinfection compared with M. tuberculosis single infection. Our data suggest a pattern in which HIV, through its effect on DCs, impairs the ability of M. tuberculosis-specific CD4 T cells to maintain a latent TB within human macrophages, which could play an early role in the subsequent development of TB.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Células Dendríticas/imunologia , HIV/imunologia , Tuberculose Latente/imunologia , Ativação de Macrófagos , Macrófagos/imunologia , Linfócitos T CD4-Positivos/patologia , Células Cultivadas , Coinfecção/microbiologia , Coinfecção/virologia , Citocinas/genética , Citocinas/imunologia , Células Dendríticas/microbiologia , Células Dendríticas/virologia , Fatores de Transcrição Forkhead/genética , Humanos , Subunidade alfa de Receptor de Interleucina-2/genética , Tuberculose Latente/virologia , Macrófagos/microbiologia , Mycobacterium tuberculosis , Fenótipo
13.
Virol Sin ; 33(6): 493-501, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30569289

RESUMO

The major difficulties of human papillomavirus (HPV) treatment are its persistence and recurrence. The HPV E7 oncoprotein-loaded dendritic cells have been evaluated as cellular vaccine in previous reports. Plasmacytoid dendritic cells (pDCs) play an essential role of connecting the innate immune response and adaptive immune response in the immune system. But they function in HPV E7 loading is unclear. To investigate whether loading of the HPV type 6b, 11, and 16 E7 proteins affects the activity of pDCs, human peripheral blood-separated pDCs and mouse bone marrow-derived pDCs were pulsed with the HPV E7 proteins. The expression levels of CD40, CD80, CD86, and MHC II were significantly upregulated in pDCs upon HPV 6b/11 E7 protein pulse. The secretion and gene expression of type I IFN and IL-6 were both upregulated by HPV 6b/11 E7 proteins, more significant than HPV 16 E7 protein. The expression of essential factors of TLR signaling pathway and JNK/p38 MAP kinase signaling pathway were all increased in HPV 6b/11 E7 proteins pulsed pDCs. Our results suggest that HPV E7 proteins could promote the differentiation and maturation of pDCs and activate the TLR and MAPK pathway to induce host innate immune response. It might be conducive to explore novel immunotherapy targeting HPV infection with HPV E7 loaded pDC.


Assuntos
Células Dendríticas/imunologia , Células Dendríticas/virologia , Papillomaviridae/imunologia , Proteínas E7 de Papillomavirus/imunologia , Animais , Diferenciação Celular , Células Cultivadas , Humanos , Imunidade Inata , Interferon-alfa/genética , Interleucina-6/genética , Camundongos , Proteínas Oncogênicas Virais/imunologia , Proteínas E7 de Papillomavirus/genética , Transdução de Sinais , Receptores Toll-Like/imunologia
14.
Nat Commun ; 9(1): 5305, 2018 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-30546110

RESUMO

HIV-1-infected people who take drugs that suppress viremia to undetectable levels are protected from developing AIDS. Nonetheless, HIV-1 establishes proviruses in long-lived CD4+ memory T cells, and perhaps other cell types, that preclude elimination of the virus even after years of continuous antiviral therapy. Here we show that the HIV-1 provirus activates innate immune signaling in isolated dendritic cells, macrophages, and CD4+ T cells. Immune activation requires transcription from the HIV-1 provirus and expression of CRM1-dependent, Rev-dependent, RRE-containing, unspliced HIV-1 RNA. If rev is provided in trans, all HIV-1 coding sequences are dispensable for activation except those cis-acting sequences required for replication or splicing. Our results indicate that the complex, post-transcriptional regulation intrinsic to HIV-1 RNA is detected by the innate immune system as a danger signal, and that drugs which disrupt HIV-1 transcription or HIV-1 RNA metabolism would add qualitative benefit to current antiviral drug regimens.


Assuntos
Fármacos Anti-HIV/farmacologia , Linfócitos T CD4-Positivos/virologia , HIV-1/crescimento & desenvolvimento , Provírus/crescimento & desenvolvimento , RNA Viral/biossíntese , Replicação Viral/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linhagem Celular , Citocinas/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/virologia , Regulação Viral da Expressão Gênica/genética , Células HEK293 , HIV-1/genética , HIV-1/imunologia , Humanos , Interferon Tipo I/metabolismo , Macrófagos/imunologia , Provírus/genética , Processamento de RNA/genética , RNA Viral/genética , Produtos do Gene rev do Vírus da Imunodeficiência Humana/genética
15.
Front Immunol ; 9: 2719, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30532754

RESUMO

The importance of myeloid cells in HIV transmission in the female genital tract is uncertain. Because it is difficult to study the early events in HIV transmission in humans, most of our knowledge is based on animal models of SIV infection in Rhesus macaques and more recently HIV infection in humanized mice. However, these models may not accurately recapitulate transmission in the human genital tract. CD14+ myeloid cells are the most abundant hematopoietic cells in the human cervical mucosa, comprising 40-50% of CD45+ mononuclear cells. Most CD14+ cells are CD14+CD11c- macrophages and about a third are CD14+CD11c+ tissue dendritic cells, which express the HIV-binding receptors, DC-SIGN and CX3CR1. To examine the role of mucosal myeloid cells in HIV transmission, we infected intact healthy human cervical explants with CCR5-tropic HIV-1 ex vivo and then sorted populations of cervical immune cells 20 h later to determine whether they took up virus and could transmit it to activated CD4 T cells. Viral RNA was detected in CD14+ myeloid cells in all but one of 10 donor tissue samples, even when HIV RNA was not detected in CD4+ T cells. HIV RNA was detected predominantly in CD14+CD11c+ dendritic cells rather than in CD14+CD11c- macrophages. The reverse transcriptase inhibitor, nevirapine, reduced HIV RNA in CD4+ T cells, but not in CD14+ cells. Moreover, integrated HIV DNA were not detected above background in myeloid cells but was detected in T cells. These data suggest that although HIV replicates in T cells, myeloid cells in the female genital mucosa capture viral particles, but do not replicate the virus at early timepoints. However, sorted CD14+ myeloid cells isolated 20 h post-infection from 5 HIV-infected cervical explants tested all transmitted HIV to activated CD4+ T cells, while only 1 sample of sorted CD4+ T cells did. Thus, myeloid cells in human cervical tissue capture HIV and are an important early cellular storage site of infectious virus.


Assuntos
Linfócitos T CD4-Positivos , Colo do Útero , Células Dendríticas , Infecções por HIV , HIV-1/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD4-Positivos/virologia , Colo do Útero/imunologia , Colo do Útero/patologia , Colo do Útero/virologia , Células Dendríticas/imunologia , Células Dendríticas/patologia , Células Dendríticas/virologia , Feminino , Infecções por HIV/imunologia , Infecções por HIV/transmissão , Humanos , Macrófagos/imunologia , Macrófagos/patologia , Macrófagos/virologia , Membrana Mucosa/imunologia , Membrana Mucosa/patologia , Membrana Mucosa/virologia , Técnicas de Cultura de Tecidos
16.
Front Immunol ; 9: 2560, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30559738

RESUMO

Viruses often subvert antiviral immune responses by taking advantage of inhibitory immune signaling. We investigated if hantaviruses use this strategy. Hantaviruses cause viral hemorrhagic fever (VHF) which is associated with strong immune activation resulting in vigorous CD8+ T cell responses. Surprisingly, we observed that hantaviruses strongly upregulate PD-L1 and PD-L2, the ligands of checkpoint inhibitor programmed death-1 (PD-1). We detected high amounts of soluble PD-L1 (sPD-L1) and soluble PD-L2 (sPD-L2) in sera from hantavirus-infected patients. In addition, we observed hantavirus-induced PD-L1 upregulation in mice with a humanized immune system. The two major target cells of hantaviruses, endothelial cells and monocyte-derived dendritic cells, strongly increased PD-L1 and PD-L2 surface expression upon hantavirus infection in vitro. As an underlying mechanism, we found increased transcript levels whereas membrane trafficking of PD-L1 was not affected. Further analysis revealed that hantavirus-associated inflammatory signals and hantaviral nucleocapsid (N) protein enhance PD-L1 and PD-L2 expression. Cell numbers were strongly reduced when hantavirus-infected endothelial cells were mixed with T cells in the presence of an exogenous proliferation signal compared to uninfected cells. This is compatible with the concept that virus-induced PD-L1 and PD-L2 upregulation contributes to viral immune escape. Intriguingly, however, we observed hantavirus-induced CD8+ T cell bystander activation despite strongly upregulated PD-L1 and PD-L2. This result indicates that hantavirus-induced CD8+ T cell bystander activation bypasses checkpoint inhibition allowing an early antiviral immune response upon virus infection.


Assuntos
Antígeno B7-H1/metabolismo , Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/fisiologia , Células Endoteliais/fisiologia , Infecções por Hantavirus/imunologia , Hantavirus/fisiologia , Proteína 2 Ligante de Morte Celular Programada 1/metabolismo , Animais , Células Cultivadas , Células Dendríticas/virologia , Células Endoteliais/virologia , Humanos , Evasão da Resposta Imune , Ativação Linfocitária , Camundongos , Camundongos SCID , Proteínas do Nucleocapsídeo/imunologia , Estudos Retrospectivos , Regulação para Cima
17.
Cell Mol Biol Lett ; 23: 43, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30202418

RESUMO

Background: Lnc-DC is a specific group of long non-coding (Lnc) RNAs in dendritic cells (DCs). Its function has been previously studied, and includes roles in dendritic cell differentiation and the progression of some diseases. In this study, we observed the critical role of Lnc-DC in regulating the differentiation, growth, and apoptosis of dendritic cells. Methods: We first isolated peripheral blood mononuclear cells to culture and induce into DCs, which were then co-cultured with hepatitis B virus (HBV)-secreting HepG2.2.15 cells for the detection of changes in Lnc-DC. The expression levels of TLR9, p-STAT3, and SOCS3 were tested with qPCR and western blot. MTT assays were used to analyze the cell proliferation, cell cycle, and apoptosis. We used ELISA to test the expression of TNF-α, IL-1ß, IL-6, IL-12p40, and IFN-γ. Results: Co-culture with HBV-secreting HepG2.2.15 cells increased the level of Lnc-DC and activated TLR9/STAT3 signaling. The HBV DNA level (IU/ml) was positively correlated with levels of Lnc-DC and TLR9, further demonstrating that Lnc-DC was associated with the immune response of HBV. Lnc-DC was shown to regulate TLR9/STAT3 signaling in dendritic cells. More interestingly, the regulation of Lnc-DC controlled the immune response by reducing the concentration of secreted TNF-α, IL-6, IL-12, and IFN-γ, as well as increasing the IL-1ß concentration in dendritic cells. Conclusion: Lnc-DC is important in regulating the growth, apoptosis, and immune response of dendritic cells mediated by TLR9/STAT3 signaling, and was also activated by HBV. This study provides a previously unidentified mechanism underlying the immune response in dendritic cells.


Assuntos
Células Dendríticas/imunologia , Vírus da Hepatite B/imunologia , Hepatite B/imunologia , RNA Longo não Codificante/imunologia , Fator de Transcrição STAT3/imunologia , Transdução de Sinais , Receptor Toll-Like 9/imunologia , Apoptose , Proliferação de Células , Células Cultivadas , Células Dendríticas/citologia , Células Dendríticas/virologia , Células Hep G2 , Humanos
18.
Viruses ; 10(8)2018 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-30126090

RESUMO

Lentiviruses are infectious agents of a number of animal species, including sheep, goats, horses, monkeys, cows, and cats, in addition to humans. As in the human case, the host immune response fails to control the establishment of chronic persistent infection that finally leads to a specific disease development. Despite intensive research on the development of lentivirus vaccines, it is still not clear which immune responses can protect against infection. Viral mutations resulting in escape from T-cell or antibody-mediated responses are the basis of the immune failure to control the infection. The innate immune response provides the first line of defense against viral infections in an antigen-independent manner. Antiviral innate responses are conducted by dendritic cells, macrophages, and natural killer cells, often targeted by lentiviruses, and intrinsic antiviral mechanisms exerted by all cells. Intrinsic responses depend on the recognition of the viral pathogen-associated molecular patterns (PAMPs) by pathogen recognition receptors (PRRs), and the signaling cascades leading to an antiviral state by inducing the expression of antiviral proteins, including restriction factors. This review describes the latest advances on innate immunity related to the infection by animal lentiviruses, centered on small ruminant lentiviruses (SRLV), equine infectious anemia virus (EIAV), and feline (FIV) and bovine immunodeficiency viruses (BIV), specifically focusing on the antiviral role of the major restriction factors described thus far.


Assuntos
Regulação da Expressão Gênica/imunologia , Imunidade Inata , Fatores Reguladores de Interferon/imunologia , Infecções por Lentivirus/imunologia , Receptores de Reconhecimento de Padrão/imunologia , Animais , Gatos , Bovinos , Células Dendríticas/imunologia , Células Dendríticas/virologia , Cabras , Cavalos , Vírus da Imunodeficiência Bovina/imunologia , Vírus da Imunodeficiência Bovina/patogenicidade , Vírus da Imunodeficiência Felina/imunologia , Vírus da Imunodeficiência Felina/patogenicidade , Vírus da Anemia Infecciosa Equina/imunologia , Vírus da Anemia Infecciosa Equina/patogenicidade , Fatores Reguladores de Interferon/genética , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/virologia , Infecções por Lentivirus/genética , Infecções por Lentivirus/virologia , Macrófagos/imunologia , Macrófagos/virologia , Padrões Moleculares Associados a Patógenos/imunologia , Receptores de Reconhecimento de Padrão/genética , Ovinos , Linfócitos T/imunologia , Linfócitos T/virologia
19.
J Virol ; 92(19)2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29997203

RESUMO

Human immunodeficiency virus type 1 (HIV-1) infection often arises from a single transmitted/founder (TF) viral variant among a large pool of viruses in the quasispecies in the transmitting partner. TF variants are typically nondominant in blood and genital secretions, indicating that they have unique traits. The plasmacytoid dendritic cell (pDC) is the primary alpha interferon (IFN-α)-producing cell in response to viral infections and is rapidly recruited to the female genital tract upon exposure to HIV-1. The impact of pDCs on transmission is unknown. We investigated whether evasion of pDC responses is a trait of TF viruses. pDCs from healthy donors were stimulated in vitro with a panel of 20 HIV-1 variants, consisting of one TF variant and three nontransmitted (NT) variants each from five transmission-linked donor pairs, and secretion of IFN-α and tumor necrosis factor alpha (TNF-α) was measured by enzyme-linked immunosorbent assay (ELISA). No significant differences in cytokine secretion in response to TF and NT viruses were observed, despite a trend toward enhanced IFN-α and TNF-α production in response to TF viruses. NT viruses demonstrated polarization toward production of either IFN-α or TNF-α, indicating possible dysregulation. Also, for NT viruses, IFN-α secretion was associated with increased resistance of the virus to inactivation by IFN-α in vitro, suggesting in vivo evolution. Thus, TF viruses do not appear to preferentially subvert pDC activation compared to that with nontransmitted HIV-1 variants. pDCs may, however, contribute to the in vivo evolution of HIV-1.IMPORTANCE The plasmacytoid dendritic cell (pDC) is the first cell type recruited to the site of HIV-1 exposure; however, its contribution to the viral bottleneck in HIV-1 transmission has not been explored previously. We hypothesized that transmitted/founder viruses are able to avoid the pDC response. In this study, we used previously established donor pair-linked transmitted/founder and nontransmitted (or chronic) variants of HIV-1 to stimulate pDCs. Transmitted/founder HIV-1, instead of suppressing pDC responses, induced IFN-α and TNF-α secretion to levels comparable to those induced by viruses from the transmitting partner. We noted several unique traits of chronic viruses, including polarization between IFN-α and TNF-α production as well as a strong relationship between IFN-α secretion and the resistance of the virus to neutralization. These data rule out the possibility that TF viruses preferentially suppress pDCs in comparison to the pDC response to nontransmitted HIV variants. pDCs may, however, be important drivers of viral evolution in vivo.


Assuntos
Células Dendríticas/imunologia , Infecções por HIV/transmissão , HIV-1/imunologia , Interferon-alfa/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Adulto , Células Dendríticas/virologia , Feminino , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/patogenicidade , Interações Hospedeiro-Patógeno , Humanos , Interferon-alfa/imunologia , Masculino , Testes de Neutralização , Cultura Primária de Células , Fator de Necrose Tumoral alfa/imunologia , Vírion/imunologia , Vírion/patogenicidade
20.
Virus Res ; 253: 28-37, 2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29859235

RESUMO

Active virus-host interactions determine the outcome of pathogen invasions. It has been shown that in isolated dendritic cells (DCs), rotavirus can induce the expression of tumor necrosis factor α (TNF-α), a vital cytokine mediating host immune responses. However, the role of TNF-α in rotavirus infection is unknown. In this study, we demonstrated that TNF-α has potent anti-rotavirus effects, independent of type I interferon production. Blocking of TNF-α by infliximab, a clinically available TNFα antibody, totally abrogated this effect. Mechanistic studies revealed that the anti-rotavirus effect of TNF-α was achieved by NFκB-regulated genes via the activation of classical nuclear factor κB (NF-κB) signaling. Our study reveals the pivotal role and the mechanism-of-actions of TNF-α in the host defense against rotavirus. Thus, this knowledge may contribute to the better understanding of the complexity of rotavirus-host interactions.


Assuntos
NF-kappa B/imunologia , Infecções por Rotavirus/imunologia , Rotavirus/fisiologia , Fator de Necrose Tumoral alfa/imunologia , Células Dendríticas/imunologia , Células Dendríticas/virologia , Humanos , NF-kappa B/genética , Rotavirus/genética , Infecções por Rotavirus/genética , Infecções por Rotavirus/virologia , Transdução de Sinais , Fator de Necrose Tumoral alfa/genética
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