ABSTRACT
A C1858T single nucleotide polymorphism within PTPN22 (which encodes PTPN22R620W) is associated with an enhanced susceptibility to multiple autoimmune diseases including type 1 diabetes and rheumatoid arthritis. Many of the associated autoimmune diseases have an autoantibody component to their pathology. Fc receptors (FcRs) recognise autoantibodies when they bind to autoantigens and form immune complexes. After immune complex binding and receptor crosslinking, FcRs signal via Src and Syk family kinases, leading to antigen uptake, presentation and cytokine secretion. Ptpn22 encodes a protein tyrosine phosphatase that negatively regulates Src and Syk family kinases proximal to immunoreceptor signalling cascades. We therefore hypothesised that PTPN22 regulates immune complex stimulated FcR responses in dendritic cells (DCs). Bone marrow derived DCs (BMDCs) from wild type (WT) or Ptpn22-/- mice were pulsed with ovalbumin:anti-ovalbumin immune complexes (ova ICs). Co-culture with WT OT-II T cells revealed that ova IC pulsed Ptpn22-/- BMDCs have an enhanced capability to induce T cell proliferation. This was associated with an increased capability of Ptpn22-/- BMDCs to present immune complex derived antigens and to form ova IC dependent DC-T cell conjugates. These findings highlight PTPN22 as a regulator of FcR mediated responses and provide a link between the association of PTPN22R620W with autoantibody associated autoimmune diseases.
Subject(s)
Protein Tyrosine Phosphatase, Non-Receptor Type 22/metabolism , Animals , Antigen-Antibody Complex/metabolism , Bone Marrow Cells/cytology , Cell Proliferation/physiology , Cells, Cultured , Dendritic Cells/cytology , Dendritic Cells/metabolism , Genetic Predisposition to Disease/genetics , Humans , Mice , Mice, Knockout , Polymorphism, Single Nucleotide/genetics , Protein Tyrosine Phosphatase, Non-Receptor Type 22/genetics , Signal Transduction/genetics , Signal Transduction/physiology , Syk Kinase/genetics , Syk Kinase/metabolism , src-Family Kinases/genetics , src-Family Kinases/metabolismABSTRACT
The PTPN22R620W single nucleotide polymorphism increases the risk of developing multiple autoimmune diseases including type 1 diabetes, rheumatoid arthritis and lupus. PTPN22 is highly expressed in antigen presenting cells (APCs) where the expression of the murine disease associated variant orthologue (Ptpn22R619W) is reported to dysregulate pattern recognition receptor signalling in dendritic cells (DCs) and promote T-cell proliferation. Because T-cell activation is dependent on DC antigen uptake, degradation and presentation, we analysed the efficiency of these functions in splenic and GM-CSF bone marrow derived DC from wild type (WT), Ptpn22-/- or Ptpn22R619W mutant mice. Results indicated no differential ability of DCs to uptake antigen via macropinocytosis or receptor-mediated endocytosis. Antigen degradation and presentation was also equal as was WT T-cell conjugate formation and subsequent T-cell proliferation. Despite the likely presence of multiple phosphatase-regulated pathways in the antigen uptake, processing and presentation pathways that we investigated, we observed that Ptpn22 and the R619W autoimmune associated variant were dispensable. These important findings indicate that under non-inflammatory conditions there is no requirement for Ptpn22 in DC dependent antigen uptake and T-cell activation. Our findings reveal that perturbations in antigen uptake and processing, a fundamental pathway determining adaptive immune responses, are unlikely to provide a mechanism for the risk associated with the Ptpn22 autoimmune associated polymorphism.
Subject(s)
Antigen Presentation , Antigens, Bacterial/chemistry , Dendritic Cells/immunology , Protein Tyrosine Phosphatase, Non-Receptor Type 22/immunology , T-Lymphocytes/immunology , Animals , Antigens, Bacterial/immunology , Coculture Techniques , Dendritic Cells/cytology , Endocytosis/immunology , Fluorescent Dyes/chemistry , Gene Expression , Immunological Synapses , Listeria monocytogenes/chemistry , Listeria monocytogenes/immunology , Lymphocyte Activation , Mice , Mice, Inbred C57BL , Mice, Knockout , Ovalbumin/chemistry , Ovalbumin/immunology , Pinocytosis/immunology , Polymorphism, Single Nucleotide , Protein Tyrosine Phosphatase, Non-Receptor Type 22/genetics , Signal Transduction , Staining and Labeling , T-Lymphocytes/cytologyABSTRACT
Inflammation triggers the differentiation of Ly6Chi monocytes into microbicidal macrophages or monocyte-derived dendritic cells (moDCs). Yet, it is unclear whether environmental inflammatory cues control the polarization of monocytes toward each of these fates or whether specialized monocyte progenitor subsets exist before inflammation. Here, we have shown that naive monocytes are phenotypically heterogeneous and contain an NR4A1- and Flt3L-independent, CCR2-dependent, Flt3+CD11c-MHCII+PU.1hi subset. This subset acted as a precursor for FcγRIII+PD-L2+CD209a+, GM-CSF-dependent moDCs but was distal from the DC lineage, as shown by fate-mapping experiments using Zbtb46. By contrast, Flt3-CD11c-MHCII-PU.1lo monocytes differentiated into FcγRIII+PD-L2-CD209a-iNOS+ macrophages upon microbial stimulation. Importantly, Sfpi1 haploinsufficiency genetically distinguished the precursor activities of monocytes toward moDCs or microbicidal macrophages. Indeed, Sfpi1+/- mice had reduced Flt3+CD11c-MHCII+ monocytes and GM-CSF-dependent FcγRIII+PD-L2+CD209a+ moDCs but generated iNOS+ macrophages more efficiently. Therefore, intercellular disparities of PU.1 expression within naive monocytes segregate progenitor activity for inflammatory iNOS+ macrophages or moDCs.
Subject(s)
Cell Differentiation/immunology , Dendritic Cells/immunology , Macrophages/immunology , Monocytes/immunology , Adoptive Transfer , Animals , Antigens, Ly/immunology , Cell Separation , Dendritic Cells/cytology , Flow Cytometry , Macrophages/cytology , Mice , Monocytes/cytology , Nitric Oxide Synthase Type II/immunology , Oligonucleotide Array Sequence Analysis , Polymerase Chain ReactionABSTRACT
Contenido: Capitulo I. 1. 2 Determinación de la calidad de servicio. 1. 3 Caracteristicas para que un servicio de salud tenga calidad, Capitulo II. 2. 1 Definición del servicio, 2. 2 Definición de servico al cliente, 2. 3 Principales caracteristicas de los servicios, 2. 4 Expectativas del cliente respecto al servicio, 2. 5 Definición de servios de salud, Capitulo III. 3. 1 Definición de procesos, 3. 2 Características de los procesos, 3. 3 Los clientes, 3. 4 Jerarquia del proceso, 3. 5 Selección de los responsables del proceso, 3. 6 Definición de los límites de un proceso, 3. 7 Representación de un proceso, 3. 8 Simbologia de un diagrama de flujo, . Capítulo IV. 4. 1 Naturaleza y domicilio de la caja nacional de salud, 4. 2 Misión, políticas, objetivos y campo de aplicación, 4. 3 Servcios, 4. 4 Organización, 4. 5 Personal, 4. 6 sDefinición de centros médicos, Capítulo V. Metodologia, 5. 1 Método de investigación, 5. 2 Tipo de estudio, 5. 3 Formulación de la hipótesis, 5. 4 Unidad de an álisis, 5. 5 Determinación del universo y la muestra, 5. 6 Técnicas de investigación, 5. 7 Operacionalización de variables, Capítulo VI. La calidad de servicio de consulta externa de la C. N. C. , 6. 1 Acceso a los servicios, 6. 2 Eficiencia, 6. 3 Continuidad y oportunidad, 6. 4 Competencia profesional, 6. 5 Conclusiones del capítulo, Capítulo VII, Expectativas del cliente respecto al servicio médico, 7. 1 Fiabilidad, 7. 2 Seguridad, comodidad y empatia, 7. 3 Capacidad de respuesta, 7. 4 Elementos tangibles, 7. 5 Conclusiones del capítulo
