Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
1.
Int J Cancer ; 146(7): 1950-1962, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31376303

RESUMO

Heme oxygenase 1 (HO-1) plays a pivotal role in preventing cell damage. Indeed, through the antioxidant, antiapoptotic and anti-inflammatory properties of its metabolic products, it favors cell adaptation against different stressors. However, HO-1 induction has also been related to the gain of resistance to therapy in different types of cancers and its involvement in cancer immune-escape has been hypothesized. We have investigated the role of HO-1 expression in Vemurafenib-treated BRAFV600 melanoma cells in modulating their susceptibility to NK cell-mediated recognition. Different cell lines, isolated in house from melanoma patients, have been exposed to 1-10 µM PLX4032, which efficiently reduced ERK phosphorylation. In three lines, Vemurafenib was able to induce only a limited decrease in cell viability, while HO-1 expression was upregulated. HO-1 silencing/inhibition was able to induce a further significant reduction of Vemurafenib-treated melanoma viability. Moreover, while NK cell degranulation and killing activity were decreased upon interaction with melanoma exposed to Vemurafenib, HO-1 silencing was able to completely restore NK cell ability to degranulate and kill. Furthermore, melanoma cell treatment with Vemurafenib downregulated the expression of ligands of NKp30 and NKG2D activating receptors, and HO-1 silencing/inhibition was able to restore their expression. Our results indicate that HO-1 downregulation can both improve the efficacy of Vemurafenib on melanoma cells and favor melanoma susceptibility to NK cell-mediated recognition and killing.


Assuntos
Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Heme Oxigenase-1/genética , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/metabolismo , Mutação , Proteínas Proto-Oncogênicas B-raf/genética , Vemurafenib/farmacologia , Biomarcadores , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Inativação Gênica , Heme Oxigenase-1/metabolismo , Humanos , Imunofenotipagem , Células Matadoras Naturais/imunologia , Receptores de Células Matadoras Naturais/metabolismo
2.
Eur J Immunol ; 47(6): 1051-1061, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28386908

RESUMO

X-linked lymphoproliferative disease 1 (XLP1) is an inherited immunodeficiency, caused by mutations in SH2D1A encoding Signaling Lymphocyte Activation Molecule (SLAM)-associated protein (SAP). In XLP1, 2B4, upon engagement with CD48, has inhibitory instead of activating function. This causes a selective inability of cytotoxic effectors to kill EBV-infected cells, with dramatic clinical sequelae. Here, we investigated the NK cell education in XLP1, upon characterization of killer Ig-like receptor (KIR)/KIR-L genotype and phenotypic repertoire of self-HLA class I specific inhibitory NK receptors (self-iNKRs). We also analyzed NK-cell cytotoxicity against CD48+ or CD48- KIR-ligand matched or autologous hematopoietic cells in XLP1 patients and healthy controls. XLP1 NK cells may show a defective phenotypic repertoire with substantial proportion of cells lacking self-iNKR. These NK cells are cytotoxic and the inhibitory 2B4/CD48 pathway plays a major role to prevent killing of CD48+ EBV-transformed B cells and M1 macrophages. Importantly, self-iNKR defective NK cells kill CD48- targets, such as mature DCs. Self-iNKR- NK cells in XLP1 patients are functional even in resting conditions, suggesting a role of the inhibitory 2B4/CD48 pathway in the education process during NK-cell maturation. Killing of autologous mature DC by self-iNKR defective XLP1 NK cells may impair adaptive responses, further exacerbating the patients' immune defect.


Assuntos
Células Matadoras Naturais/imunologia , Transtornos Linfoproliferativos/imunologia , Transtornos Linfoproliferativos/fisiopatologia , Receptores de Células Matadoras Naturais/imunologia , Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismo , Antígeno CD48/imunologia , Antígeno CD48/metabolismo , Genes MHC Classe I , Humanos , Células Matadoras Naturais/metabolismo , Ativação Linfocitária , Canais de Potássio Corretores do Fluxo de Internalização/imunologia , Receptores Imunológicos/metabolismo , Transdução de Sinais , Proteína Associada à Molécula de Sinalização da Ativação Linfocitária/metabolismo , Família de Moléculas de Sinalização da Ativação Linfocitária/imunologia
3.
Eur J Immunol ; 45(4): 1069-81, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25631937

RESUMO

CD8 T cells contribute to protective immunity against Mycobacterium tuberculosis. In humans, M. tuberculosis reactive CD8 T cells typically recognize peptides associated to classical MHC class Ia molecules, but little information is available on CD8 T cells recognizing M. tuberculosis Ags presented by nonclassical MHC class Ib molecules. We show here that CD8 T cells from tuberculosis (TB) patients recognize HLA-E-binding M. tuberculosis peptides in a CD3/TCR αß mediated and CD8-dependent manner, and represent an additional type of effector cells playing a role in immune response to M. tuberculosis during active infection. HLA-E-restricted recognition of M. tuberculosis peptides is detectable by a significant enhanced ex vivo frequency of tetramer-specific circulating CD8 T cells during active TB. These CD8 T cells produce type 2 cytokines upon antigenic in vitro stimulation, help B cells for Ab production, and mediate limited TRAIL-dependent cytolytic and microbicidal activity toward M. tuberculosis infected target cells. Our results, together with the finding that HLA-E/M. tuberculosis peptide specific CD8 T cells are detected in TB patients with or without HIV coinfection, suggest that this is a new human T-cell population that participates in immune response in TB.


Assuntos
Citocinas/biossíntese , Antígenos de Histocompatibilidade Classe I/imunologia , Mycobacterium tuberculosis/imunologia , Linfócitos T Citotóxicos/imunologia , Tuberculose/imunologia , Adulto , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Células Cultivadas , Coinfecção/imunologia , Coinfecção/microbiologia , Coinfecção/virologia , Citocinas/imunologia , Epitopos de Linfócito T/imunologia , Feminino , Infecções por HIV/imunologia , Infecções por HIV/virologia , Humanos , 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 , Ligação Proteica/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Tuberculose/microbiologia , Antígenos HLA-E
4.
Eur J Immunol ; 44(5): 1526-34, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24496997

RESUMO

X-linked lymphoproliferative disease 1 (XLP1) is a rare congenital immunodeficiency caused by SH2D1A (Xq25) mutations resulting in lack or dysfunction of SLAM-associated protein adaptor molecule. In XLP1 patients, upon ligand (CD48) engagement, 2B4 delivers inhibitory signals that impair the cytolytic activity of NK (and T) cells. This causes the selective inability to control EBV infections and the occurrence of B-cell lymphomas. Here, we show that in the absence of SLAM-associated protein, co-engagement of 2B4 with different activating receptors, either by antibodies or specific ligands on target cells, inhibits different ITAM-dependent signaling pathways including activating killer Ig-like receptors. In XLP1 NK cells, 2B4 affected both the cytolytic and IFN-γ production capabilities, functions that were restored upon disruption of the 2B4/CD48 interactions. Notably, we provide evidence that 2B4 dysfunction does not affect the activity of DNAM-1 and NKG2D triggering receptors. Thus, while CD48(+) B-EBV and lymphoma B cells devoid of NKG2D and DNAM-1 ligands were resistant to lysis, the preferential usage of these receptors allowed XLP1 NK cells to kill lymphomas that expressed sufficient amounts of the specific ligands. The study sheds new light on the XLP1 immunological defect and on the cross-talk of inhibitory 2B4 with triggering NK (and T) receptors.


Assuntos
Antígenos CD/imunologia , Antígenos de Diferenciação de Linfócitos T/imunologia , Células Matadoras Naturais/imunologia , Transtornos Linfoproliferativos/imunologia , Subfamília K de Receptores Semelhantes a Lectina de Células NK/imunologia , Receptores Imunológicos/imunologia , Transdução de Sinais/imunologia , Antígenos CD/genética , Antígenos de Diferenciação de Linfócitos T/genética , Antígeno CD48 , Infecções por Vírus Epstein-Barr/genética , Infecções por Vírus Epstein-Barr/imunologia , Infecções por Vírus Epstein-Barr/patologia , Feminino , Herpesvirus Humano 4/imunologia , Humanos , Interferon gama/genética , Interferon gama/imunologia , Células Matadoras Naturais/patologia , Linfoma de Células B/genética , Linfoma de Células B/imunologia , Linfoma de Células B/patologia , Transtornos Linfoproliferativos/genética , Transtornos Linfoproliferativos/patologia , Masculino , Subfamília K de Receptores Semelhantes a Lectina de Células NK/genética , Receptores Imunológicos/genética , Transdução de Sinais/genética , Família de Moléculas de Sinalização da Ativação Linfocitária
5.
J Allergy Clin Immunol ; 134(6): 1381-1387.e7, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24985396

RESUMO

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening, heterogeneous, hyperinflammmatory disorder. Prompt identification of inherited forms resulting from mutation in genes involved in cellular cytotoxicity can be crucial. X-linked lymphoproliferative disease 1 (XLP1), due to mutations in SH2D1A (Xq25) encoding signaling lymphocyte activation molecule-associated protein (SAP), may present with HLH. Defective SAP induces paradoxical inhibitory function of the 2B4 coreceptor and impaired natural killer (NK) (and T) cell response against EBV-infected cells. OBJECTIVE: To characterize a cohort of patients with HLH and XLP1 for SAP expression and 2B4 function in lymphocytes, proposing a rapid diagnostic screening to direct mutation analysis. METHODS: We set up rapid assays for 2B4 function (degranulation or (51)Cr-release) to be combined with intracellular SAP expression in peripheral blood NK cells. We studied 12 patients with confirmed mutation in SH2D1A and some family members. RESULTS: The combined phenotypic/functional assays allowed efficient and complete diagnostic evaluation of all patients with XLP1, thus directing mutation analysis and treatment. Nine cases were SAP(-), 2 expressed SAP with mean relative fluorescence intensity values below the range of healthy controls (SAP(dull)), and 1, carrying the R55L mutation, was SAP(+). NK cells from all patients showed inhibitory 2B4 function and defective killing of B-EBV cells. Carriers with SH2D1A mutations abolishing SAP expression and low percentage of SAP(+) cells showed neutral 2B4 function at the polyclonal NK cell level. Three novel SH2D1A mutations have been identified. CONCLUSIONS: Study of SAP expression is specific but may have insufficient sensitivity for screening XLP1 as a single tool. Combination with 2B4 functional assay allows identification of all cases.


Assuntos
Antígenos CD/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Linfo-Histiocitose Hemofagocítica/diagnóstico , Transtornos Linfoproliferativos/diagnóstico , Receptores Imunológicos/imunologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Peptídeos e Proteínas de Sinalização Intracelular/genética , Células Matadoras Naturais/imunologia , Leucócitos Mononucleares/imunologia , Linfo-Histiocitose Hemofagocítica/genética , Linfo-Histiocitose Hemofagocítica/imunologia , Transtornos Linfoproliferativos/genética , Transtornos Linfoproliferativos/imunologia , Masculino , Mutação , Proteína Associada à Molécula de Sinalização da Ativação Linfocitária , Família de Moléculas de Sinalização da Ativação Linfocitária , Adulto Jovem
6.
Eur J Immunol ; 40(5): 1440-50, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20306468

RESUMO

HIV-1 infection in humans results in an early and progressive NK cell dysfunction and an accumulation of an "anergic" CD56- CD16+ NK subset, which is characterised by low natural cytotoxicity receptor expression and low cytokine producing capacity. In contrast to humans, chimpanzee NK cells do not display a distinguishable CD56(bright) and CD56(dim) subset but, as shown here, could be subdivided into functionally different CD8+ and CD8- subsets. The CD8+ NK cells expressed significantly higher levels of triggering receptors including NKp46 and, upon in vitro activation, produced more IFN-gamma, TNF-alpha and CD107 than their CD8- counterparts. In addition, chimpanzee CD8- NK cells had relatively high levels of HLA-DR expression, suggestive of an activated state. Killing inhibitory receptors were expressed only at low levels; however, upon in vitro stimulation, they were up-regulated in CD8+ but not in CD8- NK cells and were functionally capable of inhibiting NKp30-triggered killing. In contrast to HIV-1-infected humans, infected chimpanzees maintained their dominant CD8+ NK cell population, with high expression of natural cytotoxicity receptors.


Assuntos
Citocinas/biossíntese , Infecções por HIV/imunologia , HIV-1 , Células Matadoras Naturais/imunologia , Subpopulações de Linfócitos/imunologia , Pan troglodytes/imunologia , Receptores de Células Matadoras Naturais/análise , Animais , Antígenos CD/análise , Antígenos CD/biossíntese , Antígenos CD/genética , Antígeno CD56/análise , Antígenos CD8/análise , Células Cultivadas/imunologia , Citocinas/genética , Citotoxicidade Imunológica , Humanos , Imunofenotipagem , Interferon gama/biossíntese , Interferon gama/genética , Células Matadoras Naturais/química , Subpopulações de Linfócitos/química , Subfamília C de Receptores Semelhantes a Lectina de Células NK/análise , Subfamília C de Receptores Semelhantes a Lectina de Células NK/biossíntese , Subfamília C de Receptores Semelhantes a Lectina de Células NK/genética , Receptores de Células Matadoras Naturais/biossíntese , Receptores de Células Matadoras Naturais/genética , Regulação para Cima
7.
Cells ; 9(3)2020 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-32168749

RESUMO

Observational/retrospective studies indicate that prostaglandin-endoperoxide synthase-2 (PTGS2) inhibitors could positively affect colorectal cancer (CRC) patients' survival after diagnosis. To obtain an acceptable cost/benefit balance, the inclusion of PTGS2 inhibitors in the adjuvant setting needs a selective criterion. We quantified the 72 kDa, CRC-associated, glycosylated form of PTGS2 in 100 frozen CRC specimens and evaluated PTGS2 localization by IHC in the same tumors, scoring tumor epithelial-derived and stroma-derived fractions. We also investigated the involvement of interleukin-1 beta (IL1ß) in PTGS2 induction, both in vitro and in CRC lysates. Finally, we used overall survival (OS) as a criterion for patient selection. Glycosylated PTGS2 can be quantified with high sensibility in tissue lysates, but the expression in both tumor and stromal cells limits its use for predictive purposes. Immunohistochemistry (IHC) analysis indicates that stromal PTGS2 expression could exert a protective role on patient OS. Stromal PTGS2 was prevalently expressed by cancer-associated fibroblasts exerting a barrier function near the gut lumen, and it apparently favored the antitumor M1 macrophage population. IL1ß was directly linked to gPTGS2 expression both in vitro and in tumors, but its activity was apparently prevalent on the stromal cell population. We suggest that stromal PTGS2 could exert a positive effect on patients OS when expressed in the luminal area of the tumor.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Neoplasias do Colo/tratamento farmacológico , Neoplasias Colorretais/tratamento farmacológico , Ciclo-Oxigenase 2/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Neoplasias do Colo/enzimologia , Neoplasias Colorretais/patologia , Inibidores de Ciclo-Oxigenase 2/farmacologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
8.
HLA ; 93(4): 185-194, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30828978

RESUMO

Natural killer (NK) cells are innate immune effector cells involved in the first line of defense against viral infections and malignancies. In the last three decades, the identification of HLA class I-specific inhibitory killer immunoglobulin-like receptors (KIR) and of the main activating receptors has strongly improved our understanding of the mechanisms regulating NK cell functions. The increased knowledge on how NK cells discriminate healthy cells from damaged cells has made it possible to transfer basic research notions to clinical applications. Of particular relevance is the strong NK-mediated anti-leukemia effect in haploidentical hematopoietic stem cell transplantation to cure high-risk leukemia.


Assuntos
Efeito Enxerto vs Leucemia/imunologia , Transplante de Células-Tronco Hematopoéticas , Células Matadoras Naturais/imunologia , Leucemia/imunologia , Leucemia/terapia , Receptores KIR/imunologia , Humanos , Células Matadoras Naturais/patologia , Transplante Homólogo
9.
J Invest Dermatol ; 118(4): 595-9, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11918704

RESUMO

Selection and activation of T cells is tightly regulated by both antigen-specific receptors and co-receptors to ensure that responses to self antigens are largely avoided. By T cell receptor clonotypic mapping and staining with tetrameric HLA-peptide complexes, we demonstrate the presence of melanocyte differentiation antigen MART-1 specific T cells in the areas of destruction of both neoplastic and normal melanocytic cells in a case of a primary melanoma and its associated hypopigmentation. These self reactive T cells expressed CD94/NKG2 major histocompatibility complex class I specific C-type lectin-like receptors. This family of receptors includes both activating and inhibitory isoforms. Thus, we performed a detailed analysis that revealed the exclusive presence of inhibitory NKG2-A/B receptors in the vitiligo-like leukoderma, whereas both the inhibitory receptors and the activating NKG2-C/E isoforms were present within the tumor. Our data suggest the differential expression of killer inhibitory receptors as a possible mechanism to regulate T cell responses to self antigens.


Assuntos
Lectinas Tipo C , Melanoma/imunologia , Neoplasias Cutâneas/imunologia , Linfócitos T/imunologia , Vitiligo/imunologia , Antígenos CD/genética , Antígenos de Neoplasias , Autoimunidade/imunologia , Células Clonais , Regulação Neoplásica da Expressão Gênica/imunologia , Humanos , Tolerância Imunológica/imunologia , Imuno-Histoquímica , Antígeno MART-1 , Glicoproteínas de Membrana/genética , Subfamília C de Receptores Semelhantes a Lectina de Células NK , Subfamília D de Receptores Semelhantes a Lectina de Células NK , Proteínas de Neoplasias/análise , Receptores de Antígenos de Linfócitos T alfa-beta/análise , Receptores Imunológicos/genética , Receptores de Células Matadoras Naturais , Linfócitos T/química , Linfócitos T/citologia
10.
Cancer Gene Ther ; 10(3): 209-14, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12637942

RESUMO

Dendritic cells (DC) are the most potent antigen-presenting cells known, currently tested for vaccination studies in cancer patients. The use of tumor-derived RNA to load DC overcomes the requirement of defined HLA types and the identification of tumor antigens expressed by the tumors. Here, we show that human monocyte-derived DC generated under serum-free conditions by GM-CSF, IL-4 and TNF-alpha acquire a mature phenotype and expression of the chemokine receptor CCR-7, which plays a pivotal role in DC migration to the afferent lymph nodes. We demonstrate the feasibility of total RNA transfection into such DC using the renal cell carcinoma (RCC) cell line N43-EGFP, which was stably transfected with an EGFP-encoding vector. Moreover, we show that DC transfected with RNA from colorectal cancer cells present HLA class I-restricted antigenic epitopes to induce a primary antitumor CTL response in vitro. Interestingly, the CTL induced by SW480 RNA also recognized another colon cancer line, HCT116, and the RCC line A498. Our results confirm the feasibility of total RNA transfection of serum-free generated DC for the induction of CTL against colon cancer and RCC cells, and support the relevance of shared tumor rejection epitopes between colorectal cancer and RCC.


Assuntos
Neoplasias Colorretais/imunologia , Células Dendríticas/imunologia , RNA Neoplásico/genética , Linfócitos T Citotóxicos/imunologia , Carcinoma de Células Renais/imunologia , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Neoplasias Colorretais/terapia , Humanos , Neoplasias Renais/imunologia , Receptores de Quimiocinas/metabolismo , Transfecção
11.
Oncoimmunology ; 2(4): e23638, 2013 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-23734317

RESUMO

Natural killer (NK) cells exert potent antitumor activity. However, NK cells infiltrating solid tumors are severely impaired in their function. Remarkably, NK cells isolated from malignant pleural effusions kill very efficiently tumor cells upon exposure to interleukin-2, offering an important clue for the development of novel approaches for tumor immunotherapy.

12.
Front Immunol ; 4: 15, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23378843

RESUMO

Natural killer (NK) cells are involved in innate immune responses and play a major role in tumor surveillance and in defense against viruses. Human NK cells recognize human leukocyte antigen (HLA) class I molecules via surface receptors [killer immunoglobulin-like receptor (KIR) and NKG2A] delivering signals that inhibit NK cell function and kill HLA class I-deficient target cells, a frequent event in tumors or virus-infected cells. NK cell triggering is mediated by activating receptors that recognize ligands expressed primarily on tumors or virus-infected cells. NK cells play also a key role in the cure of high-risk leukemias. Thus, donor-derived "alloreactive" NK cells are fundamental effectors in adult acute myeloid leukemia and in pediatric acute lymphoblastic leukemia patients undergoing haploidentical hematopoietic stem cell transplantation (HSCT). Alloreactive NK cells mediate killing of leukemia cells and patient's dendritic cell, thus preventing respectively leukemic relapses and graft-vs-host responses. Cytofluorimetric analysis of KIRs expressed by NK cells allows to define the size of the alloreactive NK subset and the selection of the best potential donor. Recently, it has been shown that also the expression of activating KIRs, in particular the (C2-specific) KIR2DS1, may contribute to donor NK alloreactivity. It has also been established a correlation between the size of the alloreactive NK cell population and the clinical outcome. Notably, the alloreactive NK cells derived from donor's hematopoietic stem cells are generated and persist in patients over time. The high survival rates of patients undergoing haploidentical HSCT highlight an important new reality in the setting of allograft performed to cure otherwise fatal leukemias. Novel approaches are in progress to further improve the clinical outcome based on the infusion of donor alloreactive NK cells either as a component of the transplanted cell population or as in vitro expanded NK cells.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA