Basic Immunology Introduction PDF

Basic Immunology Introduction Ninevah University College of Medicine Department of Medical Microbiology Dr. Ali Abbas Abdulkarim PhD medical microbiology and Immunology  Learning Objectives ✔ Define and describe the components of the i...

Basic Immunology Introduction Ninevah University College of Medicine Department of Medical Microbiology Dr. Ali Abbas Abdulkarim PhD medical microbiology and Immunology  Learning Objectives ✔ Define and describe the components of the immune system, ✔ Define the some terms immunology,  The World of the Immune System Our immune system protects us from the invasion of foreign organisms and substance. invades include living organism microbial toxins and other microbial byproducts and other foreign substance such as pollens pet danders and chemicals like those used in manufacturing drugs and cosmetics. our protective status immunity consisting of two distinct types innate (natural) and adaptive (acquired). The most important physiologic function of the immune system is to prevent or eradicate infections (Virus, Bacteria, Fungi, Parasite).  Define the some terms Immunity: is defined as resistance to disease, specifically infectious disease. Immune system: The collection of cells, tissues, and molecules that mediate resistance to infections. Immune response. It is the coordinated reaction of these cells and molecules to infectious microbes comprises an immune response.  Define the some terms Lymphocytes: are mononuclear cells which are part of the leukocyte cell lineage. They are subdivided into B (Bone marrow-derived) and T (Thymus-derived) lymphocytes. Lymphocytes express antigen receptors on their surface to enable recognition of a specific antigen. Basophils: originate from stem cell of bone marrow appear in many specific kinds of inflammatory reactions, particularly those that cause allergic symptoms. Basophils are a type of white blood cell called a granulocyte which cells contain granules that they use to secrete important substances. The granules inside basophils contain heparin and histamine. Eosinophils: are polymorphic multi-functional leukocytes that are typically associated with the initiation and propagation of inflammatory responses, particularly helminths infection and allergic disease.  Define the some terms Neutrophil: A type of immune cell that is one of the first cell types to travel to the site of an infection. Neutrophils help fight infection by ingesting microorganisms and releasing enzymes that kill the microorganisms. Dendritic cells: A special type of immune cell that is found in tissues, such as the skin, and boosts immune responses by showing antigens on its surface to other cells of the immune system. A dendritic cell is a type of phagocyte and a type of antigen-presenting cell (APC). Macrophage: A type of white blood cell that surrounds and kills microorganisms, removes dead cells, and stimulates the action of other immune system cells. Mast cells: A granular cell found in body tissue, especially connective tissue, that activates inflammation by releasing a variety of chemical substances including histamine, tumor necrosis factor, and interleukins.  The immune system  Role of The Immune System is to Protect Fro m Viruse Parasites s Fungi Bacteria Dr.T.V.Rao MD  The main parts of the immune system ✔ White blood cells. ✔ Antibodies. ✔ Complement system. ✔ Lymphatic system (Lymph nodes) ✔ Spleen. ✔ Bone marrow. ✔ Thymus. ✔ T cells, ✔ B cells, Immune System Components  Immune Cells and Organs Lymphoid tissue Bone marrow ✔ Two types: Thymus A. Primary lymphoid tissue: lymphocytes differentiate, proliferate and mature. Fetal liver Lymph nodes B. Secondary lymphoid tissues: lymphocytes are exert their effector function. Spleen Mucosal–associated lymphoid tissue (MALT)  Immune Cells and Organs T-CELL ✔ Pre-T lymphocyte go to the thymus gland ✔ It leaves the thymus to the secondary LT.(Lymphatic Tissues) ✔ In the spleen stay around central arterioles in white pulp. ✔ In lymph nodes, it is found in paracortex.  Immune Cells and Organs Types of T cells 1. T Helper (TH1-2) Cells: CD4+: Stimulate B cells to produce antibodies. 2. Cytotoxic T (Tc) Cells: CD8+: Destroy target cells.  Immune Cells and Organs B CELLS ✔ Pre-B lymphocyte stay in bone marrow - maturation. ✔ It leaves the bone marrow to the secondary lymphoid tissues. ✔ In the spleen stay in white pulp and form primary and secondary follicles. ✔ In lymph nodes, it is found in cortex. ✔ It differentiates into plasma cell & memory cell.  Leukocytes: Granulocytes & A granulocytes Category of white blood cells characterized by presence of granules in their cytoplasm. Short – lived for 2 – 3 days. 3 types: Neutrophils – Basophils – Scanning electron micrograph of formed elements RBC (left) Eosinophils - platelet (center) leukocyte (right)  Leukocytes: Granulocytes & A granulocytes Leukocytes: Agranulocytes. Long –lived for months. 2 types: Lymphocytes Monocytes  : Immune Cells and Organs NK cells ✔ NK cells are large granular lymphocytes. Innate cytotoxic lymphocytes. ✔ The Function cytotoxic for 1) Tumor cells (immune surveillance). Have ability to recognize and kill infected cells 2) Viral infected cells. with virus and tumor cells. 3) Bacterial, fungal, parasitic infection. 4) Release a perforin extracellular which perforate the cell and lysis it. 5) Also produce the IF- which protect the body against viral infection.  Immune Cells and Organs APC ✔ Antigen Presenting Cells are heterogeneous population of leukocytes. ✔ Found primary in the skin, lymph nodes, thymus and within mucosal epithelia. 1. Macrophages. 2. Dendritic cells: a) Interdigitating dendritic cells (ID).; Present Ag to T cell. b) Follicular dendritic cells (FD).; Present Ag to B cells.  Reference Jawetz Medical Microbiology 28th edition Copyright 2019. Thanks