Immunology: Categorization of Leukocytes Action SIAMAK BADIE, SALIMAH CHAMPSI, FANYA GAO, DANIELLE PORTER PHM142 Fall 2015 Instructor: Dr. Jeffrey Henderson

Leukocytes 5 Classes:  Neutrophils (40% - 75%)  Eosinophils (1% - 6%)  Basophils (less than 1%)  Monocytes (2% - 10%)  Lymphocytes (20% - 45%) Granulocytes Agranulocytes

Damaged Cells Cytokines DegranulationPhagocytosisNETs  Oxidative burst: use energy from NADPH to form oxygen free radicals  Release anti-microbial compounds  Trap microbes Neutrophils Characteristics: -Innate immune response -Most abundant -First responders -Granulocytes – Mechanism of Action

Basophils – Mechanism of Action B-phil Th cell B cell Produce antibodies Degranulation Allergic Response Degranulation

Eosinophils – Mechanism of Action E-phil Host Defense (Peroxidase + Rnase) Cell Activation Degranulation

Hematopoietic Stem Cells Ly6C - Monocyte CDP MDP LP MP Ly6C+ Monocyte Macrophage Monocyte- Derived DC PDC Pre-CDC PDC Classical DC Bone Marrow Blood Tissue Monocytes – Mechanism of Action - Phagocytosis - Process and present antigen to T cell - Respond to viral infection - Act as APC and control T cell responses

Cellular: Cell-Mediated Humoural: Antibody-Mediated Adaptive Immune Response B cell T cell T & B Memory Suppressor T Cells Antigen Antibodies: Signal destruction pathways Granules: breakdown cell membrane of pathogens Macrophage Helper T cell MHC Innate Immunity: NK Cells -Non specific attack on tumours and infected cells -Release cytotoxic granules to induce cell apoptosis Lymphocytes– Mechanism of Action

Summary Neutrophils:  Phagocytosis: use energy from NADPH to form oxygen free radicals  Degranulation: secrete antimicrobial compounds  Formation of neutrophil extracellular traps: trap microbes Eosinophils:  Work mainly to counter infections  Granules produce ROS/RNS and ribonucleases Basophils:  Work mainly in allergic responses  Granules contain histamine, heparin, and antiparasitic molecules Monocytes:  Circulate in blood and differentiate into macrophages and dendritic cells in tissues during inflammation  Digest pathogens and stimulate antibodies Lymphocytes:  Adaptive immunity: antibody mediated B cells and cell mediated T cells attack antigen and provide antigen memory  Innate Immunity: natural killer cells attack non-specifically through release of cytotoxic granules

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