TEST 2: Immunity Flashcards
$ Innate Immunity (nonspecific response)
-The body’s first line of defense against pathogens (present from birth)
-Provides immediate, non specific protections against variety of pathogens
-physical barrier: skin, mucous membranes, stomach acid
-Cell components: phagocytes, Natural killer cells, dendritic cells
-Triggers rapid inflammation to combat infections and initiate immune response
-Role: Provides immediate protection against pathogens while adaptive immune response is developing
-recognizes common patterns on pathogens and triggers response
$ Adaptive Immunity (acquired)
-Occurs after innate immunity has been activated
-Is specific and acquired response that develops throughout life following exposure to pathogens
-Is highly specific and targets specific antigens on pathogens (based on immunologic memory, so upon reinfection there’s a stronger faster response)
-Involves two main branches:
1. Cellular mediated by T lymphocytes
2. Humoral mediated involving B lymphocytes and antibodies
-Have receptors that specifically recognize and respond to antigens
Antibody response in Innate Vs. Adaptive Immunity
-Innate: does not involve specific antibodies. Instead, it relies on protein mediators (complement proteins and cytokines)
-Adaptive: involves production of specific antibodies (immunoglobulins) by B cells
$ Antigen
(ANYTHING foreign to your body)
-The invader
-A molecule that can trigger an immune response
-Can be foreign substances like bacteria, viruses, allergens, fungi, or self-antigens in autoimmune conditions
-Role in adaptive immunity: are essential for initiating adaptive immune response, immune system recognizes antigens as foreign invaders and mounts targeted response to combat/ eliminate them
$ Haptens
-Too small of a molecule to be immunogenic but can elicit an immune response only when attached to a larger carrier protein molecule
-ie poison ivy or allergy to PCN
$ Antibody
Aka “Immunoglobulin”
-Glycoproteins produced by B lymphocytes in response to the presence of antigens
-Classified as IgG, IgM, IgE, IgA, IgD
$ Short term immunoglobulin
(IgM)
-first immunoglobulin produced in response to an infection
-Efficient at neutralizing pathogens and activating the complement system
-IgA (mucosal immunity) and IgE (allergic responses) are also considered short term antibodies
$ Long term immunoglobulin
(IgG)
-The main antibody class responsible for long term immunity
-Provides lasting protection against pathogens and enhances immune memory
$ Antigen Presenting Cell
(APC)
-Are specialized immune cells that detect, phagocytize, and present antigenic peptides to T lymphocytes to initiate adaptive immune responses
-Play a crucial role in activating T cells (key plays in adaptive immune response)
-By presenting antigens to T cells l, they ensure that the adaptive immune system can target and eliminate pathogens
-Examples: dendritic cells, macrophages, B cells
Structure of Immunoglobulins
Aka antibodies
-Have a characteristic Y shaped structure, consisting of 2 identical heavy chains and 2 identical light chains linked by disulfide bonds
-The Y shaped molecule has 2 antigen binding sites located at the tips of the arms, allowing antibodies to recognize and bind to specific antigens with high affinity
Immunoglobulin A (IgA)
-Found mainly on mucosal areas like resp/ GI tract
-Crucial role in mucosal immunity and defense
Immunoglobulin M (IgM)
-FIRST antibody produced in response to infection
-Involved in primary immune response and acts as potent activator of complement system
Immunoglobulin G (IgG)
-Most abundant antibody in bloodstream
-Provides long term immunity
-Can cross the placenta
-Key role in immune memory
Immunoglobulin E (IgE)
-Primarily involved in allergies responses and defense against parasitic infections
-Binds to mast cells and basophils, triggering the release of histamine in response to allergens
Immunoglobulin D (IgD)
-Found mainly on the surface of B cells, where to functions as a receptor for antigen recognition
-Involved in B cell activation and maturation
$ Generic T vs. B cells
T Cells: CELLULAR IMMUNITY
-Primarily target intracellular pathogens and abnormal cells
-Stimulate cytokines to activate leukocytes response or kill target directly
-Don’t produce antibodies
-slower to respond
-when impaired, more likely to have opportunistic infection
B Cells: HUMORAL IMMUNITY
-Combat extra cellular pathogens by producing antibodies
-Secrete antibodies to fight antigens
-Respond quickly on recognition of antigen
-When impaired, systemic responses to infection and more susceptible to encapsulated organisms
$ T Cells
-Maturation: Mature in the thymus gland
-Immunity: key layers in cell mediated immunity, responding to intracellular pathogens and abnormal cells
-Antigen response: Recognize and kill antigens by antigen presenting cells and respond directly by killing infected (cytotoxic T cells) or coordinating immune responses (helper T cells)
-Mature Cell Result: mature T cells give rise to various subtypes with specific roles in immunity
-Impairment consequences: can lead to compromised cell mediated immunity, making people more susceptible intracellular pathogens and cancer.