ABSTRACT
BACKGROUND: Allergic sensitization might be influenced by the lipids present in allergens, which can be recognized by natural killer T (NKT) cells on antigen-presenting cells (APCs). The aim of this study was to analyze the effect of olive pollen lipids in human APCs, including monocytes as well as monocyte-derived macrophages (MÏ) and dendritic cells (DCs). METHODS: Lipids were extracted from olive (Olea europaea) pollen grains. Invariant (i)NKT cells, monocytes, MÏ, and DCs were obtained from buffy coats of healthy blood donors, and their cell phenotype was determined by flow cytometry. iNKT cytotoxicity was measured using a lactate dehydrogenase assay. Gene expression of CD1A and CD1D was performed by RT-PCR, and the production of IL-6, IL-10, IL-12, and TNF-α cytokines by monocytes, MÏ, and DCs was measured by ELISA. RESULTS: Our results showed that monocytes and monocyte-derived MÏ treated with olive pollen lipids strongly activate iNKT cells. We observed several phenotypic modifications in the APCs upon exposure to pollen-derived lipids. Both MÏ and monocytes treated with olive pollen lipids showed an increase in CD1D gene expression, whereas upregulation of cell surface CD1d protein occurred only in MÏ. Furthermore, DCs differentiated in the presence of human serum enhance their surface CD1d expression when exposed to olive pollen lipids. Finally, olive pollen lipids were able to stimulate the production of IL-6 but downregulated the production of lipopolysaccharide- induced IL-10 by MÏ. CONCLUSIONS: Olive pollen lipids alter the phenotype of monocytes, MÏ, and DCs, resulting in the activation of NKT cells, which have the potential to influence allergic immune responses.
Subject(s)
Allergens/immunology , Antigen-Presenting Cells/immunology , Lipids/immunology , Natural Killer T-Cells/immunology , Olea/immunology , Pollen/immunology , Antigens, CD1d/immunology , Cytokines/immunology , HumansABSTRACT
Antibody deficiencies can be caused by a variety of defects that interfere with B-cell development, maturation, and/or function. Using whole-exome sequencing we found a PIK3R1 mutation in a patient with hypogammaglobulinemia and a narrow clinical phenotype of respiratory infections. Early diagnosis is crucial; careful analysis of B and T-cells followed by genetic analyses may help to distinguish activated PI3K-delta syndrome (APDS) from other, less severe, predominantly antibody deficiencies.
Subject(s)
Agammaglobulinemia/genetics , Phosphatidylinositol 3-Kinases/genetics , Respiratory Tract Infections/genetics , Agammaglobulinemia/immunology , B-Lymphocytes/immunology , Child , Class Ia Phosphatidylinositol 3-Kinase , Female , Humans , Mutation , Phenotype , Respiratory Tract Infections/immunology , T-Lymphocytes/immunologyABSTRACT
No disponible
Subject(s)
Humans , Influenza Vaccines/adverse effects , Narcolepsy/chemically induced , Nucleoproteins/immunologyABSTRACT
No disponible
Subject(s)
Female , Humans , Male , Influenza Vaccines/therapeutic use , Influenza, Human/epidemiology , Influenza, Human/immunology , Influenza, Human/prevention & control , Life Style , Vaccination/methods , Vaccination/trends , Nutrients/methods , Nutrients/prevention & control , Vitamins/therapeutic useABSTRACT
Chemokine receptor CCR7 directs mature dendritic cells (mDCs) to secondary lymph nodes where these cells regulate the activation of T cells. CCR7 also promotes survival in mDCs, which is believed to take place largely through Akt-dependent signaling mechanisms. We have analyzed the involvement of the AMP-dependent kinase (AMPK) in the control of CCR7-dependent survival. A pro-apoptotic role for AMPK is suggested by the finding that pharmacological activators induce apoptosis, whereas knocking down of AMPK with siRNA extends mDC survival. Pharmacological activation of AMPK also induces apoptosis of mDCs in the lymph nodes. Stimulation of CCR7 leads to inhibition of AMPK, through phosphorylation of Ser-485, which was mediated by G(i)/Gßγ, but not by Akt or S6K, two kinases that control the phosphorylation of AMPK on Ser-485 in other settings. Using selective pharmacological inhibitors, we show that CCR7-induced phosphorylation of AMPK on Ser-485 is mediated by MEK and ERK. Coimmunoprecipitation analysis and proximity ligation assays indicate that AMPK associates with ERK, but not with MEK. These results suggest that in addition to Akt-dependent signaling mechanisms, CCR7 can also promote survival of mDCs through a novel MEK1/2-ERK1/2-AMPK signaling axis. The data also suggest that AMPK may be a potential target to modulate mDC lifespan and the immune response.
