RESUMEN
α-Fetoprotein (AFP) is expressed by stem-like and poor outcome hepatocellular cancer tumors and is a clinical tumor biomarker. AFP has been demonstrated to inhibit dendritic cell (DC) differentiation and maturation and to block oxidative phosphorylation. To identify the critical metabolic pathways leading to human DC functional suppression, here, we used two recently described single-cell profiling methods, scMEP (single-cell metabolic profiling) and SCENITH (single-cell energetic metabolism by profiling translation inhibition). Glycolytic capacity and glucose dependence of DCs were significantly increased by tumor-derived, but not normal cord blood-derived, AFP, leading to increased glucose uptake and lactate secretion. Key molecules in the electron transport chain in particular were regulated by tumor-derived AFP. These metabolic changes occurred at mRNA and protein levels, with negative impact on DC stimulatory capacity. Tumor-derived AFP bound significantly more polyunsaturated fatty acids (PUFA) than cord blood-derived AFP. PUFAs bound to AFP increased metabolic skewing and promoted DC functional suppression. PUFAs inhibited DC differentiation in vitro, and ω-6 PUFAs conferred potent immunoregulation when bound to tumor-derived AFP. Together, these findings provide mechanistic insights into how AFP antagonizes the innate immune response to limit antitumor immunity. SIGNIFICANCE: α-Fetoprotein (AFP) is a secreted tumor protein and biomarker with impact on immunity. Fatty acid-bound AFP promotes immune suppression by skewing human dendritic cell metabolism toward glycolysis and reduced immune stimulation.
Asunto(s)
Neoplasias Hepáticas , alfa-Fetoproteínas , Humanos , alfa-Fetoproteínas/genética , alfa-Fetoproteínas/metabolismo , Neoplasias Hepáticas/patología , Ácidos Grasos Insaturados/metabolismo , Ácidos Grasos/metabolismo , Biomarcadores/metabolismo , Células DendríticasRESUMEN
In the present study, increased levels of ANKHD1 mRNA and protein expression in leukemia cell lines are reported, as compared with normal hematopoietic cells. Furthermore, a higher expression of ANKHD1 mRNA was detected in primary acute leukemia samples than in normal hematopoietic cells (P=0.002). ANKHD1 was detected in the cytosolic and membrane fraction of cells and was co-immunoprecipitated with SHP2 in protein extracts of K562 and LNCaP cell lines. These findings suggest a role for ANKHD1 as a scaffolding protein that may be associated with the abnormal phenotype of leukemia cells.
Asunto(s)
Repetición de Anquirina , Regulación Neoplásica de la Expresión Génica , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Leucemia/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Tirosina Fosfatasas/metabolismo , Enfermedad Aguda , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Línea Celular Tumoral , Citoplasma/metabolismo , Células HL-60 , Humanos , Células K562 , Persona de Mediana Edad , Proteína Tirosina Fosfatasa no Receptora Tipo 11 , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
We recently cloned a novel Formin-family human gene, denominated human leukocyte formin and posteriorly named as FMNL1 by the HUGO Gene Nomenclature Committee. This gene is overexpressed in lymphoid malignances and is found associated with Akt. Here, we describe the expression of the FMNL1 protein in 54 frozen biopsies of non-Hodgkin's lymphoma (NHL) patients and five reactive lymph nodes. Western blot analysis revealed expression of FMNL1 in all samples studied, although the highest expression was in T-cell NHL (P<0.05).
Asunto(s)
Proteínas del Citoesqueleto/biosíntesis , Regulación Leucémica de la Expresión Génica , Linfoma de Células T/metabolismo , Proteínas de Neoplasias/biosíntesis , Adulto , Anciano , Anciano de 80 o más Años , Western Blotting , Proteínas del Citoesqueleto/genética , Femenino , Forminas , Regulación Leucémica de la Expresión Génica/genética , Humanos , Ganglios Linfáticos/metabolismo , Ganglios Linfáticos/patología , Linfoma de Células T/genética , Linfoma de Células T/patología , Masculino , Persona de Mediana Edad , Proteínas de Neoplasias/genéticaRESUMEN
Dendritic cells (DCs) are being evaluated in immunization protocols to enhance immunity against infectious diseases and cancer. Interaction of T-helper cells expressing CD40 ligand (CD40L) with its cognate CD40 receptor on DCs leads to a mature DC phenotype, characterized by increased capacity of antigen presentation to cytotoxic T cells. The authors examined the ability of third-generation self-inactivating lentiviral vectors expressing CD40L to induce autonomous maturation of ex vivo expanded human monocyte-derived dendritic cells. Transduction with lentiviral vectors achieved a highly efficient gene transfer of CD40L to DCs, which correlated with phenotypic maturation as shown by the expression of immunologic relevant markers (CD83, CD80, MHCI) and secretion of IL-12, whereas DC phenotype was not affected by a control vector expressing only the green fluorescent protein marker. Addition of recombinant IFN-gamma to DCs at the time of CD40L transduction further enhanced IL-12 production, and when co-cultured with allogeneic and autologous CD8+ and CD4+ T cells, a potent activation was observed. Autologous responses against an HLA-A2-restricted influenza peptide (Flu-M1) and a tumor-associated antigenic peptide (gp100 210M) were significantly enhanced when CD40L transduced DCs were used as antigen-presenting cells for in vitro stimulation of CD8+ cytotoxic T lymphocytes. These results demonstrate that endogenous expression of CD40L by lentivirally transduced DCs induced their autonomous maturation to a phenotype comparable to that induced by optimal concentrations of soluble CD40L, providing a novel tool for genetic manipulation of DCs.