* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download 3.Lecture 5- Resistance of the Body to infection
Survey
Document related concepts
Hygiene hypothesis wikipedia , lookup
DNA vaccination wikipedia , lookup
Lymphopoiesis wikipedia , lookup
Herd immunity wikipedia , lookup
Social immunity wikipedia , lookup
Immunocontraception wikipedia , lookup
Molecular mimicry wikipedia , lookup
Immune system wikipedia , lookup
Monoclonal antibody wikipedia , lookup
Psychoneuroimmunology wikipedia , lookup
Innate immune system wikipedia , lookup
Cancer immunotherapy wikipedia , lookup
Adaptive immune system wikipedia , lookup
Adoptive cell transfer wikipedia , lookup
Transcript
Blood Physiology Professor A.M.A Abdel Gader MD, PhD, FRCP (Lond., Edin), FRSH (London) Professor of Physiology, College of Medicine & King Khalid University Hospital King Saud University Riyadh Hematopoiesis Monocyte-macrophage system Reticulo-endothelial System Reticuloendothelial System-RES Blood Monocyte Tissue macrophage Attached (fixed) Mobile Function is phagocytosis of: • • • • Bacteria Viruses Dead tissues Foriegn particles Immune function Reticuloendothelial System-RES • RES is widespread in the body Cells of the RES: – Monocytes (blood macrophages) – Mobile and fixed tissue Macrophages – Specialiazed endothelial cells in bone marrow, lymph nodes and spleen – Reticular cells of lymph nodes spleen & bone marrow. Reticuloendothelial System-RES Cells of the RES - Distribution: • Tissue Macrophages in skin SC tissues • Tisssue Macrophages of lymph nodes • Tissue macrophages in lungs • Macrphages (kupffer cells) in the liver • Macrphages in the spleen and bone marrow Reticuloendothelial System-RES Blood Monocyte Tissue macrophage Attached (fixed) Mobile Function is phagocytosis of: • • • • Bacteria Viruses Dead tissues Foriegn particles Immune function 34 Lecture # 5 Resistance of the Body to infection Immunity & Allergy Lecture # 5 • • • • • • Immunity-Definition Antigens Immune Cells (b- & T- Lymphocytes) Antibodies and B-Lymphocytes Cellular Immunity Clinical Application Immunity? The ability of the body to resist damage (caused by micro-organisms, toxins etc) • Immune system act to maintain health (i.e. homoestatic) • Immunological defenses act against: – foreign organisms e.g. bacteria, viruses – transplanted tissue or organs Immunity -- Types 1. Acquired immunity: – – the result of attack by bacteria, viruses etc e.g. Vaccination Long lasting (Memory) 2. Innate immunity Non-specific: Examples: • Ingestion of invading organisms (phagocytosis) • Stomach acidity • Skin barrier • Lysozyme • Natural killer lymphocytes Immunity -- Types Acquired immunity: • • Specific against individual bacteria, virus, toxin, foreign tissues Basic types of acquired immunity: Humoral immunity Cell-mediated immunity B-LYMPHOCYTES Antibodies Activated T-LYMPHOCYTES (B-cell immunity) (T-cell immunity) Initiated by antigens Immunity -- Types 1. Acquired immunity 2. innate immunity – – – Non-specific ingestion of invading organisms No memory cells Phagocytic cells • • Neutrophils macrophages Antigens Antigens Antigens: • Specific chemical compounds (proteins, polysaccharides) that initiate acquired immunity • High mol. weight (>8000) • Antigenicity due to presence of characteristic epitopes (molecular groups) on its surface Antigens • If mol. Wt <8000 (Haptens), such molecules rarely act as antigens. • Haptens can act as antigens if they combine with a protein and the haptenprotein complex can initiate an immune response • Antigens Recognized either directly by lymphocyte or after being processed by macrophages The bases of Acquired Immunity are Lymphocytes Immune cells Two types: – B-Lymphocytes (Thymus independent, B-lymphocytes) Produce antibodies (Humoral Immunity) 2. T- lymphocytes (Thymus dependent, T-lymphocytes) Cellular mechanisms (Cellular Immunity) Hemopoiesis (17.9) Lymphocytes Lymphopoiesis – cont. Stem cell (thymus, lymphoid tissue & bone marrow) lymphoblast intermediate pyronophilic blast cells lymphocytes B- Lymphocytes (thymus-independents) Found in: • Bone marrow, germinal layer of lymph node, red pulp of spleen • Life span: 2-7 days • Stimulation by antigen large plasma cell (producers of antibody) • Function: Humoral immunity. Lymphocytes • B lymphocytes transform into plasma cells and secrete antibodies (17.6b) Lymphocytes • T lymphocytes can attack foreign cells directly (17.6) T-Lymphocytes (thymus dependent) Formed in: – bone marrow or lymphoid tissues – migrate to thymus Life span: 100-130 days. Circulate between blood, tissues, lymph. T-Lymphocytes (thymus dependent) Types of T-lymphocytes – T-helper – T-cytotoxic – Natural killer Functions – Cellular immunity • graft rejection • delayed hypersensitivity. – Help in antibody secretion. Helper T Cells • Identified by CD4 coreceptor. • Indirectly participate by regulating the response of both T killer and B cells. • B cells must be activated by helper T cells before they produce antibodies. T Cell Response to a Virus • Foreign antigens attach to immunoglobulins on B cells. • B cells can present the antigen with class-2 MHC molecules to helper T cells. – Stimulate B cell production, conversion to plasma cells, and antibody production. (continued) Antibodies (Immunoglobulins-Ig) Antibodies -(Immunoglobulins-Ig) • Antibody is a gamma globulin produced by plasma cells (B-lymphocytes) • Subdivided into 5 classes: – – – – – IgG, IgM IgD IgE IgA. • Bind specifically to the antigen against which they have been produced Antibody Humoral immunity (Acquired immunity) B-lymphocytes surface receptors interact with antigen B-lymphocytes proliferate to plasma cells Plasma cells secrete specific antibody to destroy the antigen • Some of the stimulated cells do not proliferate stay dormant as memory cells Humoral immunity (Acquired immunity) • Action of Antibody – Agglutination – Precipitation – Neutralization – Lysis Antibody –Antigen complex Immune Response in humoral immunity The immune response of the body when exposed to antigen 1. Primary immune response: – – – first exposure to antigen antibodies formed after a latent period one week (time needed for multiplication and maturation of lymphocytes) e.g. vaccination Immune Response in humoral immunity 2. Secondary immune response: – second exposure to the same antigen. – immediate production of high titer antibodies – Memory lymphocytes (from first exposure) act immediately when exposed to the same antigen Immune response Cellular Immunity Cellular immunity • T-cell react with antigen by its receptors and proliferate to give either: – Cytotoxic (killer) T cells CD8 (Tc) – Helper T cell CD4 (Th) – Suppressor T cells (Ts) T helper Cell • Most numerous cells • Major regulator of immune system • Secret lymphokinese acts on other cells of immune cells – Stimulate growth of other T-lymphocytes – Stimulate B-lymphocytes growth and maturation into plasma cells – Activation of macrophage system Cytotoxic T cells • T cell directly attack organism, foreign infected cells and destroyed it • Bind to antigen by surface receptors making holes in it membrane • Function: – Rejection of transplanted tissues (kidney) – Antitumor immunity – Cooperation with B cell in humoral immunity Cytotoxic T cells Clinical application • The Acquired Immune Deficiency Syndrome (AIDS) – Normal Th : Tc ratio = 2:1 – AIDS virus selectively attack Th (CD4), ratio =1:2 – Generalize inhibition of immune response – Patient prone to bacteria/ viruses infection & Cancer Humoral immunity Allergy • Excess Antibody production: hypersensitivity (allergy) • Allergins: dust, pollen, drugs. Leucocytosis (Increased WBC Count) Causes: • Physiological – Diurnal: morning evening – After physical exercise – Stress or Adrenaline injection • Disease (pathological) – Bacterial infections (tonsillitis, appendicitis – Worms infestations Leucopenia (Decreased WBC Count) Causes: – Malnutrition – Typhoid fever – Depressed bone marrow – Deficiency of Vit B12 or folic acid Leukaemia (Cancer of white cells) Causes: • chromosomal abnormality • chemicals, radiation, and viruses WBC: > 50x103 Types of leukaemia – Myeloblast leukaemia myeloid cells – Lymphoblast leukaemia lymphocytic cells • Acute or chronic • Accompanied with anaemia, bleeding Functions of Leucocytes- WBC • Defence of the body against infections and foreign invadors Neutrophils & monocytes (Blood macrophages)- Phgaocytosist/ + Immunity Macrophage (RES) system … Phagocytosis + Immunity Lymphcytes ….. IMMUNITY THANK YOU لكم جزيل الشكر