Foundations in Immunology 3 Flashcards
B Lymphocytes and Functions of Antibody + The Complement System
<p>What are properties of the adaptive immune system that is different to the innate immune system?</p>
<p>Very specific</p>
<p>Immunological memory</p>
<p>What antigen do B cells use to recognise free antigens?</p>
<p>BCR (surface IgM)</p>
<p>What receptor do T cells use when they are being shown an antigen?</p>
<p>MHC</p>
<p>How do antibodies from a memory cell bind to antigens compared to regular cells?</p>
<p>With much higher affinity</p>
<p>What is a naive B cell?</p>
<p>B cell that has not been exposed to an antigen</p>
<p>What happens once a naive B cell is exposed to an antigen?</p>
<p>Becomes a memory B cell or a plasma cell</p>
<p>What are the 2 kinds of adaptive immunity?</p>
<p>Active</p>
<p>Passive</p>
<p>What is active immunity?</p>
<p>Uses the hosts own immune cells</p>
<p>What is passive immunity?</p>
<p>Transfer of someone else's immune cells</p>
<p>Which of active and passive immunity creates immunological memory?</p>
<p>Active immunity</p>
<p>What can active and passive immunity be further classified into?</p>
<p>Natural</p>
<p>Artificial</p>
<p>Where are B cells produced?</p>
<p>Bone marrow</p>
<p>What do B cells do on activation?</p>
<p>Differentiate into plasma cells</p>
<p>What are plasma cells?</p>
<p>Responsible for antibody production</p>
<p>Is it more important for B or T cells to be tolerant?</p>
<p>T cells because B cells need the help of T cells to make antibodies</p>
<p>What happens to B cells that recognise self antigens?</p>
<p>Die in bone marrow by apoptosis</p>
<p>What are epitopes?</p>
<p>Part of the antigen that antibodies bind to</p>
<p>How can epitopes differ from each other, other than their structure and what they bind to?</p>
<p>Some induce larger immune responses than others</p>
<p>What is an antigen?</p>
<p>Any substance capable of triggering an immune response</p>
<p>What does the structure of an antibody consist of?</p>
<p>Variable region</p>
<p>Constant region</p>
<p>What are the different antibody classes?</p>
<p>IgG</p>
<p>IgA</p>
<p>IgM</p>
<p>IgD</p>
<p>IgE</p>
<p>What is IgG good for?</p>
<p>Good opsoniser</p>
<p>What is IgA good for?</p>
<p>Protects mucosal surfaces, resistant to stomach acid</p>
<p>What is IgM good for?</p>
<p>Fixing compliment and opsonisation</p>
<p>What is IgD good for?</p>
<p>No known function</p>
<p>What is IgE good for?</p>
<p>Defends against parasites, causing anaphylactic shock and allergies</p>
<p>What is the antibody structure held by?</p>
<p>Disulphide bonds</p>
<p>What are the two kinds of chains in the antibody structure?</p>
<p>Light chains</p>
<p>Heavy chains</p>
<p>What receptor is in the heavy chains?</p>
<p>Fc</p>
<p>What receptor is in the light chain?</p>
<p>Antigen binding region</p>
<p>What are the 2 kinds of light chains?</p>
<p>Lamda</p>
<p>Kappa</p>
<p>How many kinds of light chain are present in each antibody?</p>
<p>One, with both chains being identical</p>
<p>What are the 2 regions of the heavy chain?</p>
<p>Constant region</p>
<p>Variable region</p>
<p>What is the variable region?</p>
<p>Antigen binding site</p>
<p>What are the 2 ways of activating an antibody?</p>
<p>T cell dependant</p>
<p>T cell independant</p>
<p>What is used to activate antibodies without T cells?</p>
<p>Mitogen</p>
<p>What is a mitogen?</p>
<p>Antigen with a very large number of repeated epitopes</p>
<p>When do B cells produce antibodies?</p>
<p>When they are activated</p>
<p>What is the first antibody that B cells produce?</p>
<p>IgM</p>
<p>What does the class of the antibody depend on?</p>
<p>The constant region</p>
<p>When is the compliment system activated by antibodies?</p>
<p>When they are bound to an antigen</p>
<p>What are the 3 ways that antibodies eliminate pathogens by?</p>
<p>Neutralisation</p>
<p>Opsonisation</p>
<p>Compliment activation</p>
<p>What does neutralisation do?</p>
<p>Discourages of prevents pathogens from initiating an infection</p>
<p>What does opsonisation do?</p>
<p>Targets for phagocyte</p>
<p>What happens to neutralised and opsonised complexes?</p>
<p>Phagocytoses by macrophages</p>
<p>What is antibody dependant cytotoxicity (ADCC)?</p>
<p>The process of killing antibody coated target cells by leukocytes which have specific Fc receptors for these bound antibodies</p>
<p>What is humoral immunity?</p>
<p>Aspect of immunity by the macromolecules found in extracellular fluid such as secreted antibodies and compliment proteins</p>
<p>What is cell mediated immunity?</p>
<p>Immune response that does not involve antibodies, but the activation of phagocytes and antigen specific cytotoxic T cells with the release of various cytokines</p>
<p>What is the process of B cell activation and class switching?</p>
<p>1) Antigen is recognised by BCR</p>
<p>2) B cell expresses MHCII and antigen complex on its surface</p>
<p>3) Gets recognised bt TCR of TH2 cell</p>
<p>4) CD4 on B cell also binds to CD4L of TH2 cell</p>
<p>5) TH2 cell releases cytokines (IL2/4/5) which are recognised by ILR on B cell (interleukin receptor)</p>
<p>6) This determines the class switching of the B cell</p>
<p>7) B cell produces antibodies</p>
<p>What determines the class switching of the B cell?</p>
<p>The cytokines released by the helper T cell</p>
<p>What is the process of compliment mediated activation of B cell?</p>
<p>1) C3b is bound to a pathogen and degrades to C3d, C3df and iC3b</p>
<p>2) C3d reamins bound to pathogen and binds to a receptor on the surface of the B cell called CR2</p>
<p>3) Binding of CR2 and IgM greatly enhances the signals into the B cell so it is activated</p>
<p>What receptor binds to C3d on a B cell?</p>
<p>CR2</p>
OVERVIEW !!!!!!!!!
