RESUMO
Zika virus (ZIKV) is a mosquito-borne flavivirus that has emerged as a global concern because of its impact on human health. ZIKV infection during pregnancy can cause microcephaly and other severe brain defects in the developing fetus and there have been reports of the occurrence of Guillain-Barré syndrome in areas affected by ZIKV. NK cells are activated during acute viral infections and their activity contributes to a first line of defense because of their ability to rapidly recognize and kill virus-infected cells. To provide insight into NK cell function during ZIKV infection, we have profiled, using mass cytometry, the NK cell receptor-ligand repertoire in a cohort of acute ZIKV-infected female patients. Freshly isolated NK cells from these patients contained distinct, activated, and terminally differentiated, subsets expressing higher levels of CD57, NKG2C, and KIR3DL1 as compared with those from healthy donors. Moreover, KIR3DL1+ NK cells from these patients produced high levels of IFN-γ and TNF-α, in the absence of direct cytotoxicity, in response to in vitro stimulation with autologous, ZIKV-infected, monocyte-derived dendritic cells. In ZIKV-infected patients, overproduction of IFN-γ correlated with STAT-5 activation (r = 0.6643; p = 0.0085) and was mediated following the recognition of MHC class 1-related chain A and chain B molecules expressed by ZIKV-infected monocyte-derived dendritic cells, in synergy with IL-12 production by the latter cells. Together, these findings suggest that NK cells contribute to the generation of an efficacious adaptive anti-ZIKV immune response that could potentially affect the outcome of the disease and/or the development of persistent symptoms.
Assuntos
Células Matadoras Naturais/imunologia , Infecção por Zika virus/imunologia , Zika virus/fisiologia , Doença Aguda , Células Cultivadas , Estudos de Coortes , Feminino , Humanos , Interferon gama/metabolismo , Interleucina-12/metabolismo , Ativação Linfocitária , Gravidez , Receptores KIR3DL1/metabolismo , Fator de Transcrição STAT5/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Accumulating evidence majorly implicates immune dysfunction in the etiology of psychotic disorders. In particular, altered numbers and functions of natural killer (NK) cells have been described in psychosis, but interpretation has often been confounded by a number of biases, including treatment. Eighty-one first-episode psychosis (FEP) patients who subsequently received a diagnosis of either schizophrenia (SZ; n = 30) or bipolar disorder (BP; n = 31) over a five-year follow-up period were investigated for their NK cell phenotype and compared to 61 healthy controls (HCs). We found a similar proportion of CD3-CD56+ NK cells in FEP patients and HCs. The frequency of NK cells expressing the late cell activation marker HLA-DR was significantly increased in FEP patients compared to HCs, especially in patients with BP (p < 0.0001) and, to a lesser degree, in patients with SZ (p = 0.0128). Interestingly, the expression of the activating NKG2C receptor, known to be associated with infections, was higher in patients with SZ and BP than in HCs (p < 0.0001) and correlated with HLA-DR expression, altogether defining adaptive NK cells. In terms of NK cell function, we observed a suppressed capacity of SZ-derived NK cells to mount cytotoxic responses in the presence of target cells, while NK cells from patients with BP show an inability to produce IFN-γ, a cytokine pivotal to NK function. This study strongly suggests major dysfunction of NK cells in FEP with functioning impairment correlated with psychotic, manic, and depressive symptoms in subsequently diagnosed patients with SZ and BP.
Assuntos
Transtorno Bipolar , Transtornos Psicóticos , Esquizofrenia , Humanos , Imunidade Inata , Células Matadoras NaturaisRESUMO
EBV-positive and EBV-negative posttransplant lymphoproliferative disorders (PTLDs) arise in different immunovirological contexts and might have distinct pathophysiologies. To examine this hypothesis, we conducted a multicentric prospective study with 56 EBV-positive and 39 EBV-negative PTLD patients of the K-VIROGREF cohort, recruited at PTLD diagnosis and before treatment (2013-2019), and compared them to PTLD-free Transplant Controls (TC, n = 21). We measured absolute lymphocyte counts (n = 108), analyzed NK- and T cell phenotypes (n = 49 and 94), and performed EBV-specific functional assays (n = 16 and 42) by multiparameter flow cytometry and ELISpot-IFNγ assays (n = 50). EBV-negative PTLD patients, NK cells overexpressed Tim-3; the 2-year progression-free survival (PFS) was poorer in patients with a CD4 lymphopenia (CD4+ <300 cells/mm3 , p < .001). EBV-positive PTLD patients presented a profound NK-cell lymphopenia (median = 60 cells/mm3 ) and a high proportion of NK cells expressing PD-1 (vs. TC, p = .029) and apoptosis markers (vs. TC, p < .001). EBV-specific T cells of EBV-positive PTLD patients circulated in low proportions, showed immune exhaustion (p = .013 vs. TC) and poorly recognized the N-terminal portion of EBNA-3A viral protein. Altogether, this broad comparison of EBV-positive and EBV-negative PTLDs highlight distinct patterns of immunopathological mechanisms between these two diseases and provide new clues for immunotherapeutic strategies and PTLD prognosis.
Assuntos
Infecções por Vírus Epstein-Barr , Transtornos Linfoproliferativos , Transplante de Órgãos , Herpesvirus Humano 4 , Humanos , Transtornos Linfoproliferativos/etiologia , Transplante de Órgãos/efeitos adversos , Estudos ProspectivosRESUMO
Dengue virus (DENV) is the most widespread arbovirus worldwide and is responsible for major outbreaks. The host's immune response plays a crucial role in controlling this infection but might also contribute to the promotion of viral spread and immunopathology. In response to DENV infection, NK cells preferentially produce cytokines and are cytotoxic in the presence of specific antibodies. Here, we identified that DENV-2 inhibits glycogen synthase kinase 3 (GSK-3) activity to subsequently induce MHC class-1-related chain (MIC) A and MIC-B expression and IL-12 production in monocyte-derived DCs, independently of the STAT-3 pathway. The inhibition of GSK-3 by DENV-2 or small molecules induced MIC-A/B expression on monocyte-derived DCs, resulting in autologous NK cells of a specific increase in IFN-γ and TNF-α production, in the absence of direct cytotoxicity. Together, these findings identified GSK-3 as a regulator of MIC-A/B expression and suggested its role in DENV-2 infection to specifically induce cytokine production by NK cells.
Assuntos
Dengue/imunologia , Quinase 3 da Glicogênio Sintase/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Células Matadoras Naturais/imunologia , Células Cultivadas , Citocinas/biossíntese , HumanosRESUMO
Among the inflammatory myopathies, anti-tRNA-synthetase syndrome (ASyS) is a severe autoimmune condition characterized by extramuscular involvement, affecting especially the lungs. ASyS specific serological markers are anti-tRNA-synthetase autoantibodies, among which anti-histidyl-tRNA-synthetase is the most common. In the past decades, ASyS has been distinguished by unique histological features attributed to a specific pathogenesis. Research has highlighted the role of environmental factors and infections as possible triggers. Tissue modifications of histidyl-tRNA-synthetase (HisRS) expression might be responsible for the recruitment and activation of both innate and adaptive immune cells. HisRS not only acts through antigenic properties, but also through many others, including chemoattraction, innate pathway activation, and cytokine-like functions. Favored by a certain genetic background, this whole activation of immunity results in widespread and specific tissue damage and finally leads to visible heterogeneous symptoms characterizing the disease state. Understanding the pathogenesis of ASyS is essential to improving patient care by identifying biomarkers and designing new therapeutic strategies accordingly. Therefore, this review details the recent hypotheses concerning the dynamic of ASyS pathogenesis with the aim of enlightening the development of new therapeutic axes in the future.
Assuntos
Miosite/imunologia , Miosite/patologia , Animais , Histidina-tRNA Ligase/biossíntese , Histidina-tRNA Ligase/imunologia , Histidina-tRNA Ligase/metabolismo , Humanos , Miosite/genéticaRESUMO
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/metabolismoRESUMO
Antisynthetase syndrome (aSS) is characterized by the association of interstitial lung disease and myositis with anti-tRNA synthetase autoantibodies. Immune mechanisms leading to aSS could be initiated in the lungs, but the role of NK cells has not yet been studied. Both extensive NK cell phenotype and functions were compared between 33 patients and 26 controls. Direct and redirected polyfunctionality assays (degranulation and intracellular production of TNF-α and IFN-γ) were performed spontaneously or after IL-12 plus IL-18 stimulation in the presence of K562 or P815 target cells, respectively. NK cells from inactive patients showed normal phenotype, whereas active aSS revealed a differentiated NK cell profile, as indicated by increased CD57 and Ig-like transcript 2 and an inability to produce IFN-γ (p = 0.002) compared with controls. Importantly, active aSS was more specifically associated with a significant NKp30 decrease (p = 0.009), although levels of mRNA and intracellular protein were similar in aSS and healthy controls. This NKp30 decrease was strongly correlated with reduced NK cell polyfunctionality in both direct and redirected killing assays with anti-NKp30 Abs (p = 0.009 and p = 0.03, respectively), confirming its important impact in aSS. Histological studies revealed massive infiltrations of NK cells inside the lungs of aSS patients (148 versus 11/mm(2)). Taken together, these data suggest that NK cells and NKp30 could play a role in aSS pathogenesis.
Assuntos
Células Matadoras Naturais/imunologia , Miosite/imunologia , Receptor 3 Desencadeador da Citotoxicidade Natural/metabolismo , Adulto , Idoso , Antígenos CD57/genética , Feminino , Granzimas , Humanos , Interferon gama/biossíntese , Interferon gama/imunologia , Interleucina-12/sangue , Interleucina-12/imunologia , Interleucina-18/sangue , Interleucina-18/imunologia , Células K562 , Pulmão/imunologia , Pulmão/patologia , Doenças Pulmonares Intersticiais/imunologia , Masculino , Pessoa de Meia-Idade , Miosite/fisiopatologia , Receptor 3 Desencadeador da Citotoxicidade Natural/genética , Fenótipo , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/imunologia , Adulto JovemRESUMO
NK cells are key players in the fight against persistent viruses. Human cytomegalovirus (HCMV) infection is associated with the presence of a population of CD16(+) CD56(dim) NKG2C(+) NK cells in both acutely and latently infected individuals. Here, we studied the nature of these terminally differentiated NK cells in different human populations infected with HCMV: healthy donors stratified by age, thymectomized individuals, pregnant women suffering from primary CMV infection, and lung transplant patients. Both CD16(+) CD56(dim) NK- and CD8 T-cell phenotypes as well as functional capacities were determined and stratified according to age and/or CMV event. Similarly to T-cell responsiveness, we observe an accumulation over time of NKG2C(+) NK cells, which preferentially expressed CD57. This accumulation is particularly prominent in elderly and amplified further by CMV infection. Latent HCMV infection (without replication) is sufficient for NKG2C(+) CD57(+) NK cells to persist in healthy individuals but is not necessarily required in old age. Collectively, the present work supports the emerging concept that CMV shapes both innate and adaptive immunity in humans.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Memória Imunológica , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/fisiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/imunologia , Antígenos CD57/imunologia , Linfócitos T CD8-Positivos/fisiologia , Citomegalovirus/fisiologia , Infecções por Citomegalovirus/virologia , Feminino , Voluntários Saudáveis , Humanos , Transplante de Pulmão , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Fenótipo , Gravidez , Complicações Infecciosas na Gravidez/imunologia , Latência Viral , Adulto JovemRESUMO
Aspergillus fumigatus is an opportunistic human fungal pathogen that sheds galactosaminogalactan (GG) into the environment. Polymorphonuclear neutrophils (PMNs) and NK cells are both part of the first line of defense against pathogens. We recently reported that GG induces PMN apoptosis. In this study, we show that PMN apoptosis occurs via a new NK cell-dependent mechanism. Reactive oxygen species, induced by the presence of GG, play an indispensable role in this apoptotic effect by increasing MHC class I chain-related molecule A expression at the PMN surface. This increased expression enables interaction between MHC class I chain-related molecule A and NKG2D, leading to NK cell activation, which in turn generates a Fas-dependent apoptosis-promoting signal in PMNs. Taken together, our results demonstrate that the crosstalk between PMNs and NK cells is essential to GG-induced PMN apoptosis. NK cells might thus play a role in the induction of PMN apoptosis in situations such as unexplained neutropenia or autoimmune diseases.
Assuntos
Apoptose/imunologia , Aspergillus fumigatus/imunologia , Polissacarídeos Fúngicos/imunologia , Células Matadoras Naturais/imunologia , Ativação Linfocitária/imunologia , Neutrófilos/imunologia , Fatores de Virulência/imunologia , Apoptose/efeitos dos fármacos , Aspergillus fumigatus/patogenicidade , Feminino , Polissacarídeos Fúngicos/toxicidade , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Células Matadoras Naturais/patologia , Ativação Linfocitária/efeitos dos fármacos , Masculino , Subfamília K de Receptores Semelhantes a Lectina de Células NK/imunologia , Neutrófilos/patologia , Espécies Reativas de Oxigênio/imunologia , Fatores de Virulência/farmacologiaRESUMO
Solid cancers are a major adverse outcome of orthotopic liver transplantation (OLT). Although the use of chronic immunosuppression is known to play a role in T cell impairment, recent insights into the specificities of NK cells led us to reassess the potential modulation of this innate immune cell compartment after transplantation. Our extensive phenotypic and functional study reveals that the development of specific de novo noncutaneous tumors post-OLT is linked to unusual NK cell subsets with maturation defects and to uncommon cytokine production associated with the development of specific cancers. Remarkably, in CMV(+) patients, the development de novo head/neck or colorectal tumors is linked to an aberrant expansion of NK cells expressing NKG2C and a high level of intracellular TNF-α, which impact on their polyfunctional capacities. In contrast, NK cells from patients diagnosed with genitourinary tumors possessed a standard immature signature, including high expression of NKG2A and a robust production of IFN-γ. Taken together, our results suggest that under an immunosuppressive environment, the interplay between the modulation of NK repertoire and CMV status may greatly hamper the spectrum of immune surveillance and thus favor outgrowth and the development of specific de novo tumors after OLT.
Assuntos
Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/metabolismo , Citomegalovirus/imunologia , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Transplante de Fígado/efeitos adversos , Subfamília C de Receptores Semelhantes a Lectina de Células NK/metabolismo , Neoplasias/etiologia , Adulto , Idoso , Antígenos de Superfície/metabolismo , Linhagem Celular Tumoral , Análise por Conglomerados , Citocinas/metabolismo , Citomegalovirus/genética , Feminino , Humanos , Imunofenotipagem , Células Matadoras Naturais/virologia , Masculino , Pessoa de Meia-Idade , Fenótipo , Fatores de Risco , Adulto JovemRESUMO
After several decades of epidemiologic silence, chikungunya virus (CHIKV) has recently re-emerged, causing explosive outbreaks and reaching the 5 continents. Transmitted through the bite of Aedes species mosquitoes, CHIKV is responsible for an acute febrile illness accompanied by several characteristic symptoms, including cutaneous rash, myalgia, and arthralgia, with the latter sometimes persisting for months or years. Although CHIKV has previously been known as a relatively benign disease, more recent epidemic events have brought waves of increased morbidity and fatality, leading it to become a serious public health problem. The host's immune response plays a crucial role in controlling the infection, but it might also contribute to the promotion of viral spread and immunopathology. This review focuses on the immune responses to CHIKV in human subjects with an emphasis on early antiviral immune responses. We assess recent developments in the understanding of their possible Janus-faced effects in the control of viral infection and pathogenesis. Although preventive vaccination and specific therapies are yet to be developed, exploring this interesting model of virus-host interactions might have a strong effect on the design of novel therapeutic options to minimize immunopathology without impairing beneficial host defenses.
Assuntos
Febre de Chikungunya/imunologia , Febre de Chikungunya/prevenção & controle , Vírus Chikungunya/imunologia , Imunidade Adaptativa , Febre de Chikungunya/diagnóstico , Febre de Chikungunya/terapia , Humanos , Imunidade Inata , Imunoterapia , Vacinas Virais/imunologiaRESUMO
With an array of activating and inhibitory receptors, natural killer (NK) cells are involved in the eradication of infected, transformed, and tumor cells. NKp44 is a member of the natural cytotoxicity receptor family, which is exclusively expressed on activated NK cells. Here, we identify natural cytotoxicity receptor NKp44 (NKp44L), a novel isoform of the mixed-lineage leukemia-5 protein, as a cellular ligand for NKp44. Unlike the other MLL family members, NKp44L is excluded from the nucleus, but expressed at the cell-surface level; its subcellular localization is being associated with the presence of a specific C-terminal motif. Strikingly, NKp44L has not been detected on circulating cells isolated from healthy individuals, but it is expressed on a large panel of the tumor and transformed cells. The sharply decreased NK lysis activity induced by anti-NKp44L antibodies directly demonstrates the role of NKp44L in cytotoxicity. Taken together, these results show that NKp44L could be critical for NK cell-mediated innate immunity. The identification and cellular distribution of NKp44L highlight the role of this self-molecule as a danger signal to alert the NK cell network.
Assuntos
Citotoxicidade Imunológica/genética , Proteínas de Ligação a DNA/imunologia , Imunidade Inata , Células Matadoras Naturais/imunologia , Receptor 2 Desencadeador da Citotoxicidade Natural/imunologia , Motivos de Aminoácidos , Anticorpos Neutralizantes/farmacologia , Linhagem Celular Tumoral , Células Cultivadas , Citotoxicidade Imunológica/efeitos dos fármacos , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Biblioteca Gênica , Humanos , Células Matadoras Naturais/citologia , Células Matadoras Naturais/efeitos dos fármacos , Ligantes , Ativação Linfocitária , Receptor 2 Desencadeador da Citotoxicidade Natural/genética , Especificidade de Órgãos , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/genética , Isoformas de Proteínas/imunologia , Estrutura Terciária de Proteína , Técnicas do Sistema de Duplo-HíbridoRESUMO
BACKGROUND: In most cases, Zika virus (ZIKV) causes a self-limited acute illness in adults, characterized by mild clinical symptoms that resolve within a few days. Immune responses, both innate and adaptive, play a central role in controlling and eliminating virus-infected cells during the early stages of infection. AIM: To test the hypothesis that circulating T cells exhibit phenotypic and functional activation characteristics during the viremic phase of ZIKV infection. METHODS: A comprehensive analysis using mass cytometry was performed on peripheral blood mononuclear cells obtained from patients with acute ZIKV infection (as confirmed by RT-PCR) and compared with that from healthy donors (HD). The frequency of IFN-γ-producing T cells in response to peptide pools covering immunogenic regions of structural and nonstructural ZIKV proteins was quantified using an ELISpot assay. RESULTS: Circulating CD4+ and CD8+ T lymphocytes from ZIKV-infected patients expressed higher levels of IFN-γ and pSTAT-5, as well as cell surface markers associated with proliferation (Ki-67), activation ((HLA-DR, CD38) or exhaustion (PD1 and CTLA-4), compared to those from HD. Activation of CD4+ and CD8+ memory T cell subsets, including Transitional Memory T Cells (TTM), Effector Memory T cells (TEM), and Effector Memory T cells Re-expressing CD45RA (TEMRA), was prominent among CD4+ T cell subset of ZIKV-infected patients and was associated with increased levels of IFN-γ, pSTAT-5, Ki-67, CTLA-4, and PD1, as compared to HD. Additionally, approximately 30% of ZIKV-infected patients exhibited a T cell response primarily directed against the ZIKV NS5 protein. CONCLUSION: Circulating T lymphocytes spontaneously produce IFN-γ and express elevated levels of pSTAT-5 during the early phase of ZIKV infection whereas recognition of ZIKV antigen results in the generation of virus-specific IFN-γ-producing T cells.
Assuntos
Linfócitos T CD8-Positivos , Interferon gama , Infecção por Zika virus , Zika virus , Humanos , Infecção por Zika virus/imunologia , Infecção por Zika virus/epidemiologia , Adulto , Zika virus/imunologia , Feminino , Masculino , Interferon gama/metabolismo , Interferon gama/imunologia , Brasil/epidemiologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD4-Positivos/imunologia , Pessoa de Meia-Idade , Adulto Jovem , Epidemias , Ativação Linfocitária/imunologia , Linfócitos T/imunologiaRESUMO
BACKGROUND: Uterus transplantation (UTx) is an emerging therapy for women with uterine infertility. However, critical questions remain with this procedure including the mechanisms involved in graft rejection. METHODS: In this study, we analyzed the immune profile of ectocervical biopsies from 5 patients after UTx before and during their first episode of rejection using RNA sequencing, quantitative polymerase chain reaction, and imaging mass cytometry. RESULTS: We identified 530 upregulated and 207 downregulated genes associated with graft rejection. Enrichment databases revealed abnormalities of skin-associated genes and the immune system, in particular activation of T and B lymphocytes, and macrophages. Imaging mass cytometry confirmed these observations; in cervical biopsies of 3 women, rejection was associated with the presence of B-cell structures linked to tertiary lymphoid structures, and 2 biopsies from 1 woman with severe rejection episodes and poor prognosis of graft function (repeated miscarriage and implantation failures) were associated with an accumulation of HLA-DR- macrophages, producing granzyme B at the surface of the epithelium. CONCLUSIONS: We showed that rejection of a UTx graft was associated with major alterations of immune markers including the involvement of tertiary lymphoid structures, the most organized of which may be a sign of chronic rejection, and with an increase in HLA-DR- macrophages expressing granzyme B in the case of grade 3 rejection episodes according Mölne's classification. We identified potential emerging biomarkers to predict or diagnose graft rejection (Keratin 1 granzyme B, IL1ß). These findings could lead to development of improved strategies for the identification, prevention, and/or treatment of uterus graft rejection.
RESUMO
BACKGROUND: The induction of neutralizing antibodies against conserved regions of the human immunodeficiency virus type 1 (HIV-1) envelope protein is a major goal of vaccine strategies. We previously identified 3S, a critical conserved motif of gp41 that induces the NKp44L ligand of an activating NK receptor. In vivo, anti-3S antibodies protect against the natural killer (NK) cell-mediated CD4 depletion that occurs without efficient viral neutralization. METHODS: Specific substitutions within the 3S peptide motif were prepared by directed mutagenesis. Virus production was monitored by measuring the p24 production. Neutralization assays were performed with immune-purified antibodies from immunized mice and a cohort of HIV-infected patients. Expression of NKp44L on CD4(+) T cells and degranulation assay on activating NK cells were both performed by flow cytometry. RESULTS: Here, we show that specific substitutions in the 3S motif reduce viral infection without affecting gp41 production, while decreasing both its capacity to induce NKp44L expression on CD4(+) T cells and its sensitivity to autologous NK cells. Generation of antibodies in mice against the W614 specific position in the 3S motif elicited a capacity to neutralize cross-clade viruses, notable in its magnitude, breadth, and durability. Antibodies against this 3S variant were also detected in sera from some HIV-1-infected patients, demonstrating both neutralization activity and protection against CD4 depletion. CONCLUSIONS: These findings suggest that a specific substitution in a 3S-based immunogen might allow the generation of specific antibodies, providing a foundation for a rational vaccine that combine a capacity to neutralize HIV-1 and to protect CD4(+) T cells.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Anticorpos Anti-HIV/sangue , Proteína gp41 do Envelope de HIV/genética , Proteína gp41 do Envelope de HIV/imunologia , HIV-1/genética , HIV-1/imunologia , Adolescente , Adulto , Substituição de Aminoácidos , Animais , Anticorpos Neutralizantes/sangue , Contagem de Linfócito CD4 , Feminino , Humanos , Células Matadoras Naturais/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Proteínas Mutantes/genética , Proteínas Mutantes/imunologia , Mutação de Sentido Incorreto , Adulto JovemAssuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Linfoma não Hodgkin/terapia , Megacariócitos/transplante , Adulto , Aloenxertos , Antígenos CD34/sangue , Feminino , Células-Tronco Hematopoéticas/citologia , Humanos , Masculino , Megacariócitos/citologia , Pessoa de Meia-Idade , Recuperação de Função Fisiológica , Condicionamento Pré-Transplante/métodos , Transplante AutólogoRESUMO
Natural killer (NK) cells are affected by infection with human cytomegalovirus (HCMV) manifested by increased expression of the HLA-E binding activating receptor NKG2C. We here show that HCMV seropositivity was associated with a profound expansion of NKG2C(+) CD56(dim) NK cells in patients with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection. Multi-color flow cytometry revealed that the expanded NKG2C(+) CD56(dim) NK cells displayed a highly differentiated phenotype, expressed high amounts of granzyme B and exhibited polyfunctional responses (CD107a, IFN-γ, and TNF-α) to stimulation with antibody-coated as well as HLA-E expressing target cells but not when stimulated with IL-12/IL-18. More importantly, NKG2C(+) CD56(dim) NK cells had a clonal expression pattern of inhibitory killer cell immunoglobulin-like receptors (KIRs) specific for self-HLA class I molecules, with predominant usage of KIR2DL2/3. KIR engagement dampened NKG2C-mediated activation suggesting that such biased expression of self-specific KIRs may preserve self-tolerance and limit immune-pathology during viral infection. Together, these findings shed new light on how the human NK-cell compartment adjusts to HCMV infection resulting in clonal expansion and differentiation of educated and polyfunctional NK cells.
Assuntos
Seleção Clonal Mediada por Antígeno , Citomegalovirus/imunologia , Hepatite Crônica/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Células Matadoras Naturais/metabolismo , Subpopulações de Linfócitos/metabolismo , Adulto , Anticorpos Antivirais/sangue , Autoantígenos/imunologia , Antígeno CD56/metabolismo , Diferenciação Celular , Processos de Crescimento Celular , Células Cultivadas , Citocinas/metabolismo , Citomegalovirus/patogenicidade , Feminino , Regulação da Expressão Gênica/imunologia , Hepatite Crônica/sangue , Hepatite Crônica/virologia , Humanos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/patologia , Células Matadoras Naturais/virologia , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/patologia , Subpopulações de Linfócitos/virologia , Masculino , Pessoa de Meia-Idade , Subfamília C de Receptores Semelhantes a Lectina de Células NK/metabolismo , Receptores KIR2DL2/imunologia , Receptores KIR2DL2/metabolismo , Antígenos HLA-ERESUMO
Chikungunya virus (CHIKV) is a worldwide emerging pathogen. In humans it causes a syndrome characterized by high fever, polyarthritis, and in some cases lethal encephalitis. Growing evidence indicates that the innate immune response plays a role in controlling CHIKV infection. We show here that CHIKV induces major but transient modifications in NK-cell phenotype and function soon after the onset of acute infection. We report a transient clonal expansion of NK cells that coexpress CD94/NKG2C and inhibitory receptors for HLA-C1 alleles and are correlated with the viral load. Functional tests reveal cytolytic capacity driven by NK cells in the absence of exogenous signals and severely impaired IFN-γ production. Collectively these data provide insight into the role of this unique subset of NK cells in controlling CHIKV infection by subset-specific expansion in response to acute infection, followed by a contraction phase after viral clearance.
Assuntos
Infecções por Alphavirus/imunologia , Citotoxicidade Imunológica/imunologia , Células Matadoras Naturais/imunologia , Adolescente , Adulto , Antígeno CD56/imunologia , Febre de Chikungunya , Vírus Chikungunya/imunologia , Feminino , Antígenos HLA-C/imunologia , Humanos , Subpopulações de Linfócitos/imunologia , Masculino , Pessoa de Meia-Idade , Subfamília C de Receptores Semelhantes a Lectina de Células NK/imunologia , Subfamília D de Receptores Semelhantes a Lectina de Células NK/imunologia , Receptores de Células Matadoras Naturais/análiseRESUMO
Normal chondrocytes display susceptibility to lysis by natural killer (NK) cells and this phenomenon may play a role in some inflammatory cartilage disorders. The mechanisms of chondrocyte recognition and killing by NK cells remain unclear. Using flow cytometry and immunohistochemical staining we found that normal human articular chondrocytes constitutively express a ligand for NKp44, one of stimulatory NK cell receptors involved in recognition and killing of target cells. Expression of NKp44 ligand by normal articular chondrocytes is not involved in their killing by unstimulated NK cells; however, it is responsible for anti-chondrocyte cytotoxicity mediated by long-term activated NK cells. Thus, expression of NKp44 ligand may play a role in chondrocyte destruction in course of chronic inflammatory cartilage disorders.