RESUMO
Tumor-associated macrophages (TAM) are abundant in several tumor types and usually correlate with poor prognosis. Previously, we demonstrated that anti-inflammatory macrophages (M2) inhibit NK cell effector functions. Here, we explored the impact of TAM on NK cells in the context of clear-cell renal cell carcinoma (ccRCC). Bioinformatics analysis revealed that an exhausted NK cell signature strongly correlated with an M2 signature. Analysis of TAM from human ccRCC samples confirmed that they exhibited an M2-skewed phenotype and inhibited IFN-γ production by NK cells. Moreover, human M0 macrophages cultured with conditioned media from ccRCC cell lines generated macrophages with an M2-skewed phenotype (TAM-like), which alike TAM, displayed suppressive activity on NK cells. Moreover, TAM depletion in the mouse Renca ccRCC model resulted in delayed tumor growth and reduced volume, accompanied by an increased frequency of IFN-γ-producing tumor-infiltrating NK cells that displayed heightened expression of T-bet and NKG2D and reduced expression of the exhaustion-associated co-inhibitory molecules PD-1 and TIM-3. Therefore, in ccRCC, the tumor microenvironment polarizes TAM toward an immunosuppressive profile that promotes tumor-infiltrating NK cell dysfunction, contributing to tumor progression. In addition, immunotherapy strategies targeting TAM may result in NK cell reinvigoration, thereby counteracting tumor progression.
Assuntos
Carcinoma de Células Renais , Interferon gama , Neoplasias Renais , Células Matadoras Naturais , Macrófagos Associados a Tumor , Células Matadoras Naturais/imunologia , Carcinoma de Células Renais/imunologia , Carcinoma de Células Renais/patologia , Interferon gama/metabolismo , Interferon gama/imunologia , Humanos , Animais , Camundongos , Neoplasias Renais/imunologia , Neoplasias Renais/patologia , Macrófagos Associados a Tumor/imunologia , Macrófagos Associados a Tumor/metabolismo , Progressão da Doença , Linhagem Celular Tumoral , Microambiente Tumoral/imunologia , Subfamília K de Receptores Semelhantes a Lectina de Células NK/metabolismo , Receptor Celular 2 do Vírus da Hepatite A/metabolismo , Receptor Celular 2 do Vírus da Hepatite A/imunologia , Receptor de Morte Celular Programada 1/metabolismoRESUMO
PROBLEM: Endometriosis exhibits several immune dysfunctions, including deficient natural killer (NK) cell cytotoxicity. MICA (MHC class I chain-related molecule A) is induced by biological stress and soluble MICA (sMICA) negatively modulates the expression of the activating receptor, NKG2D, reducing NK cells activities. We investigated the involvement of soluble MICA in NK cell-deficient activity in endometriosis. METHODS OF STUDY: sMICA levels (serum and peritoneal fluid-PF) were evaluated by ELISA. Circulating NK cell subsets quantification and its NKG2D receptor expression, NK cell cytotoxicity and CD107a, IFN-γ and IL-10 expressions by NK cells stimulated with K562 cells were determined by flow cytometry. RESULTS: We found higher sMICA levels (serum and PF) in endometriosis, especially in advanced and deep endometriosis. Endometriosis presented lower percentages of CD56dim CD16+ cytotoxic cells and impaired NK cell responses upon stimulation, resulting in lower CD107a and IFN-γ expressions, and deficient NK cell cytotoxicity. NK cell stimulation in the MICA-blocked condition (mimicking the effect of sMICA) showed decreased cytotoxicity in initial endometriosis stages and the emergence of a negative correlation between CD107a expression and sMICA levels. CONCLUSIONS: We suggest that soluble MICA is a potential player in endometriosis pathophysiology with involvement in disease progression and severity, contributing to NK cell impaired IFN-γ response and degranulation. NK cell compartment exhibits multiple perturbations, including quantitative deficiency and impaired cytotoxicity, contributing to inadequate elimination of ectopic endometrial tissue.
Assuntos
Endometriose , Feminino , Humanos , Degranulação Celular , Células Matadoras Naturais , Expressão Gênica , Progressão da Doença , Subfamília K de Receptores Semelhantes a Lectina de Células NK/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismoRESUMO
Non-Hodkin's lymphoma (NHL) is the most frequent hematologic malignancy in humans and dogs. NKG2D is one of the most critical receptors on NK cells, recognizing their natural ligands on malignant cells such as A and B major histocompatibility complex-related proteins (MIC-A and MIC-B). Soluble molecules (sMIC-A and sMIC-B) can interfere with immune synapsis between NK cells and tumor cells, impeding NK cytotoxicity. The main objectives of this study were to analyze, in dogs with diffuse large B cell lymphoma, NK cell lymphoma, and reactive lymphadenopathies, the role of NK cells, their activating receptors NKG2D and NKp46, and their ligands MIC-A and MIC-B, as well as soluble molecules sMIC-A and sMIC-B. Thirty-six dogs with a possible diagnosis of NHL and eight healthy dogs were studied. NHL was diagnosed in 28 (78 %) dogs; in the other 8 (22 %), reactive lymphadenopathies were present. Most of the lymphomas corresponded to B cell NHL (82 %). The most predominant subtype was diffuse large B cell lymphoma (21, 71.5 %), followed by five cases (18 %) that were Non-B Non-T lymphomas (presumably NK cell lymphomas) and other B cell lymphomas (3, 10.5%). There were no cases of T cell NHL. MIC-A was positive in 7 of 27 (26 %) cases of NHL, and MIC-B in 20 of 27 (74 %) NHL. In non-malignant lymphadenopathies, three (37.5 %) dogs were positive for MIC-A, and five (62.5 %) expressed MIC-B. Dogs with lymphoma had higher numbers of NK cells than eight healthy dogs. In 15 dogs (12 cases with NHL and three cases with reactive adenopathies) and eight controls, there were no differences in the number of NK cells expressing NKP46 and NKG2D. NHL dogs had higher values of sMIC-A and sMIC-B. B-cell and NK cell lymphomas correspond to 86 % and 14 % of all canine lymphomas. MIC-A, MIC-B, and sMIC-A and sMIC-B were increased in canine lymphomas.
Assuntos
Doenças do Cão , Linfadenopatia , Linfoma Difuso de Grandes Células B , Animais , Cães , Doenças do Cão/metabolismo , Células Matadoras Naturais , Linfadenopatia/metabolismo , Linfadenopatia/veterinária , Linfoma Difuso de Grandes Células B/veterinária , Linfoma Difuso de Grandes Células B/metabolismo , Subfamília K de Receptores Semelhantes a Lectina de Células NK/metabolismoRESUMO
BACKGROUND: Natural killer (NK) cells, as professional cytotoxic cells, play a key role against cancer in the early and metastatic stages. Their functional defects are highly associated with the initiation or progression of breast cancer (BC). Here, we investigated the phenotypic characterization of NK cells in 26 newly diagnosed BC patients in comparison to 12 healthy counterparts. METHODS: Expression of CXCR3 and PD-1, and also NKG2D, and TGF-ßRII were studied on CD56dim and CD56bright NK cells from fresh peripheral blood (PB) samples using flow cytometry. The plasma levels of IFN-γ and soluble MIC-A levels were also assessed by ELISA. RESULTS: Both CD56dim and CD56bright NK subtypes showed lower CXCR3 and NKG2D expression in BC patients than healthy subjects. Furthermore, patients' CD56bright NK cells significantly showed higher expression levels of TGF-ßRII and PD-1. Interestingly, increased concentration of MIC-A level in plasma of BC patients was associated with the higher TGF-ßRII and PD-1 expression in all NK cells, while the plasma level of IFN-γ was associated with the lower TGF-ßRII expression on CD56bright NK cells in these patients. CONCLUSION: Our results demonstrated phenotypically suppressed-NK cells, especially in the CD56bright subset of BC patients. It specifies their potential incompetence and outlines decrement of their anti-tumor activity, which could be interrelated with the tumor pathogenesis, TME immunosuppression, and so disease progression. The induction of compensatory mechanisms revives NK cells function and could be used in combination with the conventional treatments as a putative therapeutic approach for targeted immunotherapy.
Assuntos
Neoplasias da Mama , Receptor de Morte Celular Programada 1 , Humanos , Feminino , Subfamília K de Receptores Semelhantes a Lectina de Células NK , Antígeno CD56/análise , Antígeno CD56/metabolismo , Células Matadoras NaturaisRESUMO
NKG2D is a major natural killer (NK) cell-activating receptor that recognizes eight ligands (NKG2DLs), including MICA, and whose engagement triggers NK cell effector functions. As NKG2DLs are upregulated on tumor cells but tumors can subvert the NKG2D-NKG2DL axis, NKG2DLs constitute attractive targets for antibody (Ab)-based immuno-oncology therapies. However, such approaches require a deep characterization of NKG2DLs and NKG2D cell surface expression on primary tumor and immune cells. Here, using a bioinformatic analysis, we observed that MICA is overexpressed in renal cell carcinoma (RCC), and we also detected an association between the NKG2D-MICA axis and a diminished overall survival of RCC patients. Also, by flow cytometry (FC), we observed that MICA was the only NKG2DL over-expressed on clear cell renal cell carcinoma (ccRCC) tumor cells, including cancer stem cells (CSC) that also coexpressed NKG2D. Moreover, tumor-infiltrating leukocytes (TIL), but not peripheral blood lymphoid cells (PBL) from ccRCC patients, over-expressed MICA, ULBP3 and ULBP4. In addition, NKG2D was downregulated on peripheral blood NK cells (PBNK) from ccRCC patients but upregulated on tumor-infiltrating NK cells (TINK). These TINK exhibited impaired degranulation that negatively correlated with NKG2D expression, diminished IFN-γ production, upregulation of TIM-3, and an impaired glucose intake upon stimulation with cytokines, indicating that they are dysfunctional, display features of exhaustion and an altered metabolic fitness. We conclude that ccRCC patients exhibit a distorted MICA-NKG2D axis, and MICA emerges as the forefront NKG2DL for the development of targeted therapies in ccRCC.
Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Carcinoma de Células Renais/terapia , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Neoplasias Renais/terapia , Subfamília K de Receptores Semelhantes a Lectina de Células NK/metabolismo , Receptores de Células Matadoras NaturaisRESUMO
BACKGROUND: Natural killer (NK) cells are paramount for immunity against infectious agents and tumors. Their cytokine and cytolytic responses can be mediated by natural killer group 2, member D (NKG2D), an activating receptor whose ligands (NKG2DL) expression is induced in conditions of cell stress and malignant transformation. Since sustained expression of NKG2DL MICA is related to lower survival rates in gastric adenocarcinoma patients, and Helicobacter pylori infection contributes to tumorigenesis; we asked whether H. pylori stimulus could promote NKG2DL expression on human gastric adenocarcinoma cells. METHODS: Heat-killed H. pylori (HKHP) was used to stimulate MKN45 cells before analysis of NKG2DL and Toll-like receptor 4 (TLR4) protein levels by flow cytometry and transcripts by real-time PCR. LPS from Rhodobacter sphaeroides and inhibitory peptide Pepinh MYD were used to inhibit TLR4/MyD88 signaling pathway to assess its participation on NKG2DL expression. NK cell-mediated cytotoxicity was measured by lactate dehydrogenase (LDH) and CD107a mobilization assays. RESULTS: Stimulation of MKN45 cells with HKHP increased MICA, ULBP4 (another NKG2DL), and TLR4 at the protein and transcriptional levels. MICA, but not ULBP4 expression, was upregulated in a TLR4/MyD88-dependent manner. Furthermore, the presence of NKG2DL on the surface of HKHP-stimulated MKN45 cells enabled NK cell cytotoxic activation. CONCLUSIONS: Our data indicate that induction of NKG2DL expression on gastric adenocarcinoma cells by H. pylori promotes an immune response that may ultimately contribute to either gastric tissue damage, as a consequence of persistent activation of immunity, or tumor immune evasion due to chronic NKG2DL expression.
Assuntos
Adenocarcinoma , Infecções por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Temperatura Alta , Humanos , Ligantes , Subfamília K de Receptores Semelhantes a Lectina de Células NK , Receptor 4 Toll-LikeRESUMO
BACKGROUND: Natural killer and cytotoxic CD8+ T cells are major players during antitumor immunity. They express NKG2D, an activating receptor that promotes tumor elimination through recognition of the MHC class I chain-related proteins A and B (MICA and MICB). Both molecules are overexpressed on a great variety of tumors from different tissues, making them attractive targets for immunotherapy. However, tumors shed MICA and MICB, and the soluble forms of both (sMICA and sMICB) mediate tumor-immune escape. Some reports indicate that anti-MICA antibodies (Ab) can promote the restoration of antitumor immunity through the induction of direct antitumor effects (antibody-dependent cell-mediated cytotoxicity, ADCC) and scavenging of sMICA. Therefore, we reasoned that an active induction of anti-MICA Ab with an immunogenic protein might represent a novel therapeutic and prophylactic alternative to restore antitumor immunity. METHODS: We generated a highly immunogenic chimeric protein (BLS-MICA) consisting of human MICA fused to the lumazine synthase from Brucella spp (BLS) and used it to generate anti-MICA polyclonal Ab (pAb) and to investigate if these anti-MICA Ab can reinstate antitumor immunity in mice using two different mouse tumors engineered to express MICA. We also explored the underlying mechanisms of this expected therapeutic effect. RESULTS: Immunization with BLS-MICA and administration of anti-MICA pAb elicited by BLS-MICA significantly delayed the growth of MICA-expressing mouse tumors but not of control tumors. The therapeutic effect of immunization with BLS-MICA included scavenging of sMICA and the anti-MICA Ab-mediated ADCC, promoting heightened intratumoral M1/proinflammatory macrophage and antigen-experienced CD8+ T cell recruitment. CONCLUSIONS: Immunization with the chimeric protein BLS-MICA constitutes a useful way to actively induce therapeutic anti-MICA pAb that resulted in a reprogramming of the antitumor immune response towards an antitumoral/proinflammatory phenotype. Hence, the BLS-MICA chimeric protein constitutes a novel antitumor vaccine of potential application in patients with MICA-expressing tumors.
Assuntos
Anticorpos Monoclonais/farmacologia , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Linfoma/imunologia , Proteínas Recombinantes de Fusão/imunologia , Neoplasias da Bexiga Urinária/imunologia , Animais , Brucella/enzimologia , Feminino , Antígenos de Histocompatibilidade Classe I/genética , Linfoma/patologia , Linfoma/terapia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Complexos Multienzimáticos/genética , Complexos Multienzimáticos/imunologia , Subfamília K de Receptores Semelhantes a Lectina de Células NK/genética , Subfamília K de Receptores Semelhantes a Lectina de Células NK/imunologia , Células Tumorais Cultivadas , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/terapiaRESUMO
Gastric cancer (GC) is the third most common cause of cancer-related death worldwide. Invariant natural killer T (iNKT) cells are innate-like cytotoxic T lymphocytes involved in tumor immune surveillance. They can be activated either through CD1d-presented glycolipid antigens recognized by their invariant T-cell receptor, cytokines or by sensing tumor-associated stress-induced ligands through the natural killer group 2, member D (NKG2D) receptor. Although the number and functionality of iNKT cells may be decreased in several types of cancer, here we show that GC patients presented a mild increase in iNKT cell frequencies and numbers in the blood compared with healthy donors. In GC patients, iNKT cells, expanded in vitro with α-galactosyl ceramide and stimulated with phorbol 12-myristate 13-acetate and ionomycin, produced higher levels of interleukin-2 and transforming growth factor-beta, while their capacity to degranulate remained preserved. Because tumor-derived epithelial cell adhesion molecule-positive epithelial cells did not display surface CD1d, and NKG2D ligands (NKG2DLs) were detected in the gastric tumor milieu, we envisioned a role for NKG2D in iNKT cell functions. Peripheral iNKT cells from GC patients and controls presented similar levels of NKG2D; nevertheless, the percentages of interferon-γ-producing and CD107a-positive iNKT cells from patients were reduced upon challenge with CD1d-negative, NKG2DL-positive K562 cells, suggesting a compromised response by iNKT cells in GC patients, which may not result from impaired NKG2D/NKG2DL signaling. The decreased response of iNKT cells may explain the fact that higher frequencies of circulating iNKT cells did not confer a survival benefit for GC patients. Therefore, functional impairment of iNKT cells in GC may contribute to tumor immune escape and favor disease progression.
Assuntos
Células T Matadoras Naturais , Neoplasias Gástricas , Antígenos CD1d , Citocinas/imunologia , Humanos , Células K562 , Ativação Linfocitária , Subfamília K de Receptores Semelhantes a Lectina de Células NK/imunologia , Células T Matadoras Naturais/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Neoplasias Gástricas/imunologiaRESUMO
NK cells have been seen as potential agents in adoptive immunotherapy for cancer. The main challenge for the success of this approach is to obtain a great quantity of activated NK cells for adoptive transfer. The present study had aimed to evaluate the effect of a feeder layer of irradiated MSCs in the in vitro expansion of NK cells. MSCs were obtained from the bone marrow (BM) cells remaining in the bag and filter used in the transplantation of hematopoietic stem cells. NK cells were obtained from peripheral blood (PB) of healthy volunteers. NK expansion and activation were stimulated by culture with artificial antigen-presenting cells (aAPCs) and IL-2, in the presence or absence of BM-MSCs. NK cell proliferation, phenotypic expression and cytotoxic activity were evaluated. Both culture conditions showed high NK purity with predominance of NK CD56brightCD16+ subset post expansion. However, cultures without the presence of MSCs showed higher NK proliferation, expression of activation markers (CD16 and NKG2D) and related cytotoxic activity. In this experimental study, the presence of a feeder layer of irradiated BM-MSCs interfered negatively in the expansion of PB-NKs, limiting their growth and activation. Further investigation is needed to understand the mechanisms of NK-MSC interaction and its implications.
Assuntos
Células Apresentadoras de Antígenos/citologia , Células Matadoras Naturais/citologia , Leucócitos Mononucleares/citologia , Células-Tronco Mesenquimais/citologia , Células Apresentadoras de Antígenos/imunologia , Proliferação de Células , Células Cultivadas , Técnicas de Cocultura , Proteínas Ligadas por GPI/metabolismo , Regulação da Expressão Gênica , Voluntários Saudáveis , Humanos , Interleucina-2/metabolismo , Células K562 , Células Matadoras Naturais/imunologia , Leucócitos Mononucleares/imunologia , Células-Tronco Mesenquimais/imunologia , Subfamília K de Receptores Semelhantes a Lectina de Células NK/metabolismo , Receptores de IgG/metabolismoRESUMO
Cervical carcinoma and cervical intraepithelial neoplasia (CIN) are associated with persistent infection by oncogenic subtypes of HPV (Human Papillomavirus). Factors linked to immunity, genetics and others like oral contraceptive use, sexual behavior, coinfections with other microorganisms and smoking seem to influence the mechanisms that determine regression or progression to CIN and cervical cancer. We investigated the effect of the MHC class I chain-related gene A (MICA) and Killer Cell Lectin Like receptor K1 (KLRK1) genes on cervical cancer and CIN lesions susceptibility in a group of 195 patients from southern Brazil. There were found a significantly higher number of ex-smokers in the control group (p = 0.005). There were more oral contraceptives (OC) users in the patient group. MICA*008:01/04 allele showed a significant difference between patient and control groups (p = 0.03; OR = 0.63, 95% CI 0.41-0.96), as well as MICA*018:01(p = 0.004, OR = 0.15, 95% CI 0.03-0.64) and MICA*002:01/020 (p = 0.01; OR = 0.60, 95% CI 0.40-0.88). We also analyzed cases and controls according to the MICA-129 genotypes (Met/Val). There was found a difference (p = 0.02) with the Met/Val genotype in a higher frequency in controls and Val/Val and Val/MICA del at a higher frequency in the patient group. For the KLRK1 gene there was no significant difference between groups.