IMMUNOLOGY IMMUNOLOGY

ONTOGENY OF THE IMMUNE CELL Learning Objective : ONTOGENY OF • Learn the origin and function of cells of the immune system THE IMMUNE • Antigen recognition molecule of the CELL • Understand generation of receptor diversity Content ONTOGENY OF 1. Origin THE IMMUNE 2. Cell • Lymphoid CELL • Myeloid 3. Functions Origin involves the production development differentiation and maturation the blood cells( ONTOGENY OF erythrocytes , and leukocytes) from THE IMMUNE multipotent stem cell The site of haematopoiesis changes during development. CELL Yolk Sac Liver and spleen Bone marrow ONTOGENY OF THE IMMUNE CELL

Origin These multipotent stem cells found in the bone marrow have the ability to undergo asymmetric division. One of the two daughter cells will serve to renew the population of stem cells (self renewal), while the other can give rise to common lymphoid progenitor cell to common myeloid ONTOGENY OF progenitor cell. Different ion into various cell will be guided by the various type of cytokines and growth factors. THE IMMUNE Common lymphoid progenitor- , , cell Common Myeloid Progenitor- Erythrocytes, Megakaryocytes, , , , , and Dendric cell. ONTOGENY OF THE IMMUNE CELL

Haematopoiesis Function The white blood cells of both Myeloid and Lymphoid stem cells have specialized function in the body once their differentiation in the bone marrow is complete. Cell of the ONTOGENY OF myeloid lineage, except erythrocytes and megakaryocytes, perform specific stereotypical response and are members THE IMMUNE of the innate branch of the immune response. B and T lymphocyte of lymphoid linage perform CELL focused, antigen specific roles in immunity. Natural killer cells are also from the lymphoid lineage but participate in innate immunity. Both B and T lymphocyte are morphological indistinguishable at the level of low magnification light microscope, they represent two independent cell lineage B lymphocyte remain in bone marrow to complete their development ONTOGENY OF T lymphocyte leave the bone marrow and undergo the development within Thymus TH EIMMUNE Both B and T lymphocyte have surface receptor which bind to specific antigens. We will discuss the generation of CELL these receptors later. The natural killer cell( the third type of lymphocyte) is a large granular lymphocyte that recognizes Tumor and viral infected cells though non specific binding. Cells Myeloid : Neutrophils Basophils ONTOGENY OF Eosinophils THE IMMUNE Monocytes CELL Dendric cell Mast Cell Lymphoid: B cell T cell, Plasma cell, NK cells Myeloid Cells

ONTOGENY OF Neutrophils THE IMMUNE Most abundant WBC ~ 70% CELL Segmented lobular nuclei- 3-5 lobes Small pink cytoplasmic granules Phagocytic activity aimed at killing extracellular pathogens ONTOGENY OF THE IMMUNE CELLS

Neutrophils Neutrophils The name derives from staining characteristics on haematoxylin and eosin (H&E) hi stological or cytological preparation s. Whereas basophilic white blood cells stain dark blue and eosinophilic white blood cells stain bright red, neutrophils stain a neutral pink. Normally, neutrophils contain a nucleus divided into 2–5 lobes. Eosinophils Circulating recruited int o loose connective ONTOGENY OF tissue of respiratory and Gi tract Bilobed nuclei THE IMMUNE Large red cytoplasmic granules CELL Elimination of large extracellular parasite Type 1 in Hypersensitivity ONTOGENY OF THE IMMUNE CELL

Eosinophils ONTOGENY OF THE IMMUNE CELL

Eosinophils Mast Cells Reside in most tissues adjacent to blood vessels Granulocyte with ONTOGENY OF Small nuclei THE IMMUNE Large blue cytoplasmic CELLS Elimination of large parasites Type 1 hypercreativity ONTOGENY OF THE IMMUNE CELL

Mast Cell Origin ONTOGENY OF THE IMMUE CELLS

MAST CELL Low frequency ONTOGENY OF Circulating in blood Granulocyte with bilobed nucleus and large blue THE IMMUNE cytoplasmic granules CELLS Elimination of large extra cellular parasite Type 1 Hypersensitivity ONTOGEMY OF THE IMMUNE CELL

BASOPHIL ONTOGENY OF THE IMMUNE CELLS

BASOPHIL vs Circulating blood cell ONTOGENY OF Agranulocyte THE IMMUNE Bean or kidney shaped nucleus CELLS Precursor of macrophages ONTOGENY OF THE IMMUNE CELL

Monocyte ONTOGENY OF THE IMMUNE CELL

Monocyte Macrophages • Resident of all tissue • Agranulocyte ONTOGENY OF • Ruffled cytoplasmic membrane THE IMMUNE • Phagocytic CELLS • Professional APC • T cell activator ONTOGENY OF THE IMMUNE CELLS

MACROHAGES Dendric cells Resident in epithelial and lymphoid tissue Agranulocyte ONTOGENY OF Stellate like cytoplasmic projections THE IMMUNE CELLS Profession APC T cell activator Dendric cells Dendric cell Lymphocyte Blood stream and secondary lymphoid tissues Large dark nucleus with rim of cytoplasm ONTOGENY OF Surface marker THE IMMUNE B cell : CD19, 20 ,21 T cell: CD3 CELLS Helper T cell : CD4 CTLs :CD8 Lymphocyte Lymphocyte B cell T Cell Plasma cells Blood stream ONTOGENY OF Secondary lymphoid tissue and Bone marrow THE IMMUNE Small eccentric nucleus Intensely staining Golgi apparatus CELLS Terminal B lymphocyte that secret antibodies Plasma cell Plasma Cell Natural Killer cell Blood Stream ONTOGENY OF Lymphocyte with large cytoplasmic granule THE IMMUNE Surface marker CD 15, 56 Kills virally infected cell and Tumor cell CELLS Natural Killer Cell Normal lab values of different cells Neutrophils 50-70 % ONTOGENY OF Band cells 0-5 Lymphocytes 20-40 THE IMMUNE Monocytes 5-10 CELLS Eosinophil 0-5 Basophil <1 Chapter Summary ONTOGENY OF Site of hemopoiesis Yolk sac- Liver, spleen, Bone marrow THE IMMUNE Stem Cells Lymphoid B cell-- plasma Cell, T cell, NK cell CELLS Myeloid - Rest all