CU 4

• Innate immunity exists from birth, prior to exposure to antigens, while adaptive immunity occurs after exposure to antigens

  
• The two arms of the adaptive defense system are Humoral immunity & Cellular immunity
• The main function of the immune system is to defend the host against infection caused by viruses, bacteria, fungi, and parasites
• The primary lymphoid organs are the thymus and bone marrow, while the secondary lymphoid organs are the spleen, lymph nodes, tonsils, adenoids, bronchus, mesenteric, and Peyer's patch
• Humoral immunity includes antibody activity and primary and secondary responses
• Antibodies are globulin proteins (immunoglobulins) that react with specific antigens that stimulated their production
• The five main classes of antibodies are IgA, IgD, IgE, IgG, and IgM
• The primary antibody response becomes detectable in serum after 7-10 days in the initial interaction with the antigen, while the secondary response is faster and larger than the primary response
• Cell-mediated immunity is important in defense against fungi, parasites, tumors, and rejection of organ transplants
• Hypersensitivity reactions result in exaggerated or inappropriate immune responses that are harmful to the host
• There are four main types of hypersensitivity reactions: Type I - Immediate Anaphylactic, Type II - Cytotoxic/Cytolytic, Type III - Immune Complex, and Type IV - Delayed (cell-mediated)
• A vaccine is a substance used to provide immunity against diseases by stimulating the production of antibodies in the body
• Two types of immunizations are passive immunization and active immunization
• Passive immunization involves administering purified antibodies, known as immune globulins, while active immunization involves injecting vaccines made from organisms or their derivatives
• Vaccine types include:

  • Inactivated vaccines
  • Live-attenuated vaccines
  • Messenger RNA (mRNA) vaccines
  • Subunit, recombinant, polysaccharide, and conjugate vaccines
  • Toxoid vaccines
• Factors considered in vaccine development:

  • Immune system's microbial response
  • Who should get the vaccine?
  • The best vaccine production method
• Passive immunity is resistance based on antibodies preformed in another host, while active immunity is resistance induced after contact with foreign antigens
• Adjuvant is any foreign material introduced with an antigen to enhance its immunogenicity, e.g., killed bacteria
• Helper cells are a functional subclass of T cells which can help generate cytotoxic T cells and cooperate with B cells in the production of antibody responses
• Immunocompetent person is someone who is able to mount a normal immune response; a person whose immune system is functioning properly
• Killer (K) cells are a type of cytotoxic lymphocyte that is able to mediate antibody-dependent cellular cytotoxicity (ADCC)
• Memory cells mediate innate immune memory and their functional significance in inflammatory and infectious diseases
• Mucosa-associated lymphoid tissue (MALT) is lymphoid tissue associated with the bronchial tree, gastrointestinal tract, and other mucosa
• Natural killer (NK) cells are a type of cytotoxic lymphocyte that has the intrinsic ability to recognize and destroy virally infected cells and some tumor cells
• Suppressor cells are functionally defined populations of T cells which reduce the immune responses of other T cells or B cells
• Valence vaccine may be monovalent or multivalent, designed to immunize against one or multiple viruses of the same microorganism
• Langerhan's cell antigen presenting cells of the ski which emigrate to local lymph nodes to become dendritic cells.
• Monovalent Vaccine design to be immune against a single microorganism or single antigen.
• Multivalent or polyvalent vaccine made to immunize against two or more viruses of the same microorganism.