Components Of The Immune System Immunology PDF

Components of the Immune System Immunology Nov 21, 2024 Rod Russell [email protected] @RodRussell99  The Big Picture immune response faster antibodies...

Components of the Immune System Immunology Nov 21, 2024 Rod Russell [email protected] @RodRussell99  The Big Picture immune response faster antibodies delling  Objectives Distinguish between innate immunity and acquired 6421 immunity Identify and describe the cellular components of the 6444 immune system Describe the lymphoid organs, structures, associated 6445 cells & functions Explain why lymphocyte recirculation is necessary for 7089 antigen trapping and development of immunity  Importance of the Immune System Defense against infection – (like in a pandemic!!!) Vaccines/Immunization Defense against tumors Barriers to transplantation Immunotherapy against infection Immunotherapy against cancer  Challenges to the Immune System needs to be: > - what immune system Specificity Diversity Memory Specialization Resolution Non-reactivity to self Mobility  Immune “defense” From the time of conception, human beings are under constant attack from numerous pathogens. It must defend against “enemies” invading from: – air (viruses, bacteria, fungi, pollen, dander) – water (viruses, bacteria, parasites, foods) – surface (viruses, bacteria, fungi, parasites) – internal (autoimmune disease, cancer)  How does the immune system * IMP recognize potential invaders? The most fundamental function/ability of the immune system is the recognition of “self” versus “non-self”. – Immune system is trained to not to react against our own bodies > - is line of defense Does so by mounting “Innate” and “Acquired” immune responses, whereby: – Innate = Nonspecific response – Acquired = Specific response  Two types of Immunity INNATE IMMUNITY ACQUIRED IMMUNITY (nonspecific) (specific) – Basic elements we are – More specialized elements that born with, which are we acquire after birth always available on – Present only in vertebrates short notice – Only present if the individual – Include body surfaces, has had prior contact with a mucous membranes, the given agent cough reflex, even pH – Initial contact represents and fever “immunization”, which triggers – phagocytic cells such as activation of lymphocytes and macrophages, production of antibodies granulocytes, natural – Results in immunity to killer (NK) cells subsequent attack by the same agent How does our body generate such an effective, elaborate system?  from Hematopoiesis: > all - cells come the developmentFigure 1-3 Done marrow (Stemcells) of blood and blood-derived cells specki *QUIZ what cells gen ? from lymph - B, T , K * ↑ white cells ? - Cancer/immune response The Myeloid Lineage Important mostly in innate immunity, but some play important roles in adaptive immunity as well.  The Myeloid Lineage + up Macrophages mainly new out reside in tissues and ↑ spit # are derived from blood monocytes. Most dendritic cells reside in lymphoid organs and are also derived from monocytes. Both play a major role in the innate immune response by phagocytosing bacteria and killing them. The Myeloid Lineage Neutrophils, Eosinophils and Basophils are often called granulocytes because of the large number of granules in their cytoplasm. These granules have the ability to kill certain types of bacteria and parasites. They are referred to as polymorphonuclear cells because of their oddly shaped nucleus, consisting of one or more lobes. The Myeloid Lineage They mainly reside in tissues and play an important role in response to worms and other parasites. Triggering these cells to release chemical mediators such as histamine, affects the vascular endothelia, making it more permeable and allowing cells such as neurtrophils to squeeze through the gaps between the endothelia cells and to reach the invading bacteria in the tissues. * IMP The Lymphoid Lineage B-cells mature in the Bone Marrow and express antigen-specific immunoglobulin receptors. Antigen-activated B-cells differentiate into plasma cells which make antibodies specific for the antigen. T-cells mature in the Thymus and have antigen-specific receptors called T-cell receptors (TCR). – Main types are: CD4 helper T-cells CD8 cytotoxic or killer T-cells Natural killer (NK) cells mature in the bone marrow. NK cells do not have ~ antigen-specific receptors and are antigen-specific = clear infection important in innate immune responses.  The Lymphoid Lineage Figure 1-9 part 1 of 6 Cannot be distinguished based on morphologically; can only determine the subset, i.e. T vs B, using antibodies that specifically recognize a “cluster of differentiation” marker, such as CD4 or CD8. Plasma cells reside in the lymph nodes and are very rarely found in the blood and if they are, it’s indicative of pathology such as a cancer called myeloma.  · It , ook cogunat The Lymphoid Lineage re S Timingdiff NK cells are important in killing certain virally infected cells as well as in killing cancer cells that have lost expression of histocompatibility markers. There are many types of NK cells including NK-T cells, and although considered part of the innate immune system, they also function in adaptive immunity.  are * IMP 2: What pres ? Antigen-Presenting Cells QUI 3 antigen ↳ link biw innate - adapt immunity & Called antigen presenting cells because they can take up and digest antigens such as pathogens and foreign protein. The digested material result in peptides that are displayed on MHC class II molecules and are presented to CD4 positive T-cells. innate until antigen-pres - then specific ! - everythings Macrophages are Distributed Throughout the Reticuloendothelial System NOT TESTABLE Note: ALL of these macrophages originated from blood monocytes.  Lymphocytes are Distributed in Specialized Lymphoid Tissues #mobility All lymphoid cells, except T- cells, mature in the BM. Lymphoid progenitors destined to be T-cells arise in BM, but migrate to the Thymus, where they differentiate into mature CD4 and CD8 T-cells. Lymphatics are vessels that drain extracellular fluid (lymph) from peripheral tissues and Red areas = Primary passes through lymph nodes Lymphoid Tissues and into the thoracic duct which Yellow areas = dumps it into the left subclavian Secondary Lymphoid vein, i.e. sampling. Tissues Q: How do immune cells find pathogens in order to respond to them? A: Lymphocyte Recirculation -Lymph picks up pathogens and debris as well as macrophages and/or DC that have phagocytosed pathogens -Bring them to the nearest lymph node (called the draining lymph node) -A specific immune response can ensue  The Lymph Node NOTESTABLE small organs (< 1 cm) that form junctions where a number of afferent lymphatic vessels bringing lymph from tissues join to form one large efferent lymphatic vessel. during an infection pathogens, debris and APC arrive in the lymph The Big Picture More of the Big Picture * NOT TESTABLE make now to vaccine ? - whats protective/ what we need - Bor T  How Vaccines Work not alire + * MRNA = 2D4 make new protein -chew up + Spit out  # NOT TESTABLE The Immune Response RN Primary Response IgM antibodies Secondary e specific IgG/IgA antibodies Higher levels Stronger binding Don’t forget the T cells! Source: Kuby 1. Please review the material on D2L for the Tetanus Immunity Tutorial before coming to class. 2. Read the Tetanus Tutorial Plan. 3. Do the Pre-Test! Thanks!