The Vacuolar Pathway in Macrophages Plays a Major Role in Antigen Cross-Presentation Induced by the Pore-Forming Protein Sticholysin II Encapsulated Into Liposomes

Cross-presentation is an important mechanism for the differentiation of effector cytotoxic T lymphocytes (CTL) from naïve CD8+ T-cells, a key response for the clearance of intracellular pathogens and tumors. The liposomal co-encapsulation of the pore-forming protein sticholysin II (StII) with ovalbumin (OVA) (Lp/OVA/StII) induces a powerful OVA-specific CTL activation and an anti-tumor response in vivo. However, the pathway through which the StII contained in this preparation is able to induce antigen cross-presentation and the type of professional antigen presenting cells (APCs) involved have not been elucidated. Here, the ability of mouse bone marrow-derived dendritic cells (BM-DCs) and macrophages (BM-MΦs) stimulated with Lp/OVA/StII to activate SIINFEKL-specific B3Z CD8+ T cells was evaluated in the presence of selected inhibitors. BM-MΦs, but not BM-DCs were able to induce SIINFEKL-specific B3Z CD8+ T cell activation upon stimulation with Lp/OVA/StII. The cross-presentation of OVA was markedly decreased by the lysosome protease inhibitors, leupeptin and cathepsin general inhibitor, while it was unaffected by the proteasome inhibitor epoxomicin. This process was also significantly reduced by phagocytosis and Golgi apparatus function inhibitors, cytochalasin D and brefeldin A, respectively. These results are consistent with the concept that BM-MΦs internalize these liposomes through a phagocytic mechanism resulting in the cross-presentation of the encapsulated OVA by the vacuolar pathway. The contribution of macrophages to the CTL response induced by Lp/OVA/StII in vivo was determined by depleting macrophages with clodronate-containing liposomes. CTL induction was almost completely abrogated in mice depleted of macrophages, demonstrating the relevance of these APCs in the antigen cross-presentation induced by this formulation

Diseño de un programa de seguridad basado en el comportamiento en la empresa Tropical Coffee Company S.A.S

TABLA DE CONTENIDO 1. JUSTIFICACIÓN Y DELIMITACIÓN 1 1.1 Justificación 1 1.2 Delimitación 2 1.2.1 Delimitación de Tiempo 2 1.2.2 Delimitación de Espacio 2 2. PROBLEMA DE INVESTIGACIÓN 3 2.1 Descripción del problema 3 2.2 Pregunta de investigación 5 3. HIPÓTESIS 6 4. OBJETIVOS 7 4.1 Objetivo general 7 4.2 Objetivos específicos 7 5. MARCO DE REFERENCIA 8 5.1 Estado del arte 8 5.1.1 Principios de la psicología del comportamiento 14 5.1.2 Teoría tricondicional 14 5.1.3 Siete principios y fundamentos básicos de la SBC 15 5.1.4 Gestión de SBC 17 5.2 Marco conceptual 18 5.3 Variables sociodemográficas 22 5.4 Marco Legal 23 6. MARCO METODOLÓGICO 24 6.1 Paradigma 24 6.1.1 Tipo de estudio 24 6.2 Método de la investigación 25 6.2.1 Etapa 1. Diagnóstico de la teoría tricondicional de comportamientos. 26 6.2.2 Etapa 2. Comportamientos seguros. 26 6.2.3 Etapa 3. Diseño del programa de seguridad basado en el comportamiento. 27 6.3 Fuentes y técnicas de recolección de la información 27 6.3.1. Instrumentos 28 6.3.2 Procesamiento de Datos 28 6.3.3. Análisis de los datos 29 6.4 Población y muestra 29 7. CRONOGRAMA 31 8. PRESUPUESTO 32 9. RESULTADOS 33 9.1 Encuesta diagnóstico teoría tricondicional del comportamiento seguro 33 9.1.1 Puede 33 9.1.2 Sabe 37 9.1.3 Quiere 41 9.2 Observaciones de comportamientos 45 9.2.1 Priorización de comportamientos inseguros 46 9.2.2 Ficha de observación de comportamientos seguros 48 10. ANÁLISIS DE RESULTADOS 50 10.1 Diagnóstico teoría tricondicional del comportamiento seguro 50 10.2 Observación de comportamientos 51 11. CONCLUSIONES Y RECOMENDACIONES 53 11.1 Conclusiones 53 11.2 Recomendaciones 54 12. REFERENCIAS 55 13. ANEXOS 59 Anexo 1. Encuesta diagnostico comportamiento seguro 59 Anexo 2. Registro de observación de comportamientos en campo 61 Anexo 3. Programa de seguridad basado en el comportamiento 62 Anexo 4. Procedimiento observación de comportamientos seguros 63 Anexo 5. Ficha de observacióEspecializaciónEspecialista en Gerencia de la Seguridad y Salud en el TrabajoEspecialización en Gerencia de la Seguridad y Salud en el Trabaj

Immunoglobulin G Fc glycans are not essential for antibody-mediated immune suppression to murine erythrocytes

No abstract available

Phosphocholine-specific antibodies improve T-dependent antibody responses against OVA encapsulated into phosphatidylcholine-containing liposomes.

Liposomes containing phosphatidylcholine have been widely used as adjuvants. Recently, we demonstrated that B-1 cells produce dipalmitoyl phosphatidylcholine (DPPC)-specific IgM upon immunization of BALB/c mice with DPPC-liposomes encapsulating ovalbumin (OVA). Although this preparation enhanced the OVA-specific humoral response, the contribution of anti-DPPC antibodies to this effect was unclear. Here, we demonstrate that these antibodies are secreted by B-1 cells independently of the presence of OVA in the formulation. We also confirm that these antibodies are specific for phosphocholine. The anti-OVA humoral response was partially restored in B-1 cells-deficient BALB/xid mice by immunization with the liposomes opsonized with the serum total immunoglobulin (Ig) fraction containing anti-phosphocholine antibodies, generated in wild type animals. This result could be related to the increased phagocytosis by peritoneal macrophages of the particles opsonized with the serum total Ig or IgM fractions, both containing anti-phosphocholine antibodies. In conclusion, in the present work it has been demonstrated that phosphocholine-specific antibodies improve T-dependent antibody responses against OVA carried by DPPC-liposomes

THP-1 cells transduced with CD16A utilize Fcγ receptor I and III in the phagocytosis of IgG-sensitized human erythrocytes and platelets.

Fc gamma receptors (FcγRs) are critical effector receptors for immunoglobulin G (IgG) antibodies. On macrophages, FcγRs mediate multiple effector functions, including phagocytosis, but the individual contribution of specific FcγRs to phagocytosis has not been fully characterized. Primary human macrophage populations, such as splenic macrophages, can express FcγRI, FcγRIIA, and FcγRIIIA. However, there is currently no widely available monocyte or macrophage cell line expressing all these receptors. Common sources of monocytes for differentiation into macrophages, such as human peripheral blood monocytes and the monocytic leukemia cell line THP-1, generally lack the expression of FcγRIIIA (CD16A). Here, we utilized a lentiviral system to generate THP-1 cells stably expressing human FcγRIIIA (CD16F158). THP-1-CD16A cells treated with phorbol 12-myristate 13-acetate for 24 hours phagocytosed anti-D-opsonized human red blood cells primarily utilizing FcγRI with a lesser but significant contribution of IIIA while phagocytosis of antibody-opsonized human platelets equally utilized FcγRI and Fcγ IIIA. Despite the well-known ability of FcγRIIA to bind IgG in cell free systems, this receptor did not appear to be involved in either RBC or platelet phagocytosis. These transgenic cells may constitute a valuable tool for studying macrophage FcγR utilization and function

THP-1-CD16A macrophages with phagocytosed IgG-opsonized human platelets.

Three different images are shown of IgG-opsonized platelets incubated with THP-1-CD16A macrophages. Platelets were labelled with 5- chloromethylfluorescein diacetate (CMFDA) (green) before phagocytosis. Non-phagocytosed platelets were differentiated after phagocytosis using an AF647-conjugated anti-human CD42a antibody (red). Platelets were additionally defined by size (roughly 1.5 to 3.5 μm) to distinguish them from internalized microparticles or platelet aggregates. THP-1-CD16A macrophages were observed by spinning-disc confocal microscopy under 63x objective oil immersion with differential interference contrast and DAPI stain on a Quorum multi-modal imaging system (Quorum Technologies, Ontario, Canada). Four images were taken at the center of each well with Z-stacking. Phagocytosis was quantified using Imaris v9.6.0. Scale bar = 3 μm. White arrows indicate examples of phagocytosed platelets.</p

Analysis of FcγRIIIA transfection in HEK293T cells.

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Flow cytometric analysis of size, granularity and CD14 expression on THP-1-CD16A.

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