3.1 Adaptive Immunity Flashcards
First line of defense
Outer/Mechanical Barriers
Second line of defense
Inflammatory process + innate immune response
Third line of defense
IMMUNITY
What are the 2 purposes of immunity?
- To defend the body against invasion/infection by antigens
- To patrol for/destroy abnormal or damaged cells
What happens when an INAPPROPRIATE IMMUNE RESPONSE occurs?
Disease + disorder
What are the components of adaptive immunity?
White Blood Cells from lymphoid line
- T cells/lymphocytes
- B cells/lymphocytes
What are the 2 types of T cells
white blood cells, adaptive immunity
- cytotoxic
- helper
What is a type of B cell
white blood cell, humoral immunity, secrete antibodies
- plasma cells = antibody production
What type of immune response is our adaptive immune response
- SPECIFIC immune response
- important that body recognize foreign/abnormal cells
What does the body use to recognize our self cells?
Human Leukocyte Antigen Proteins (HLA)
- immune system ignores own cells
- recognizes antigens, bacteria, microorganisms
What is a special feature of adaptive immunity in encountering an antigen
Memory cells produced to respond quickly to antigens another time
What are the 2 types of adaptive immunity?
- Cell mediated
- Humoral
Def. Cell Mediated
- Mediated by Cytotoxic T Lymphocytes (CD8 cells)
- helper T Lymphocytes (Th1+2)
- help defends/destroy against viruses
- (since they invade self cells +; damage its DNA)
- body needs to recognize self cells that are abnormal
- generate memory cells
Def. Humoral Immunity
- B Lymphocytes develop into plasma cells
- which secrete Antibodies
(IgA, D, E, G, M) who attack non self cells/antigens - generate memory cells
Def. Antigens
- foreign substances
Def. Antibodies
- released by B plasma cells
- recognize and defend against antigens
Where are HLA’s located?
On Major Histocompatibility Complex (MHC) Molecules
What are Class I MHC molecules?
- found on all cells w/ nucleus
- presented outside cell
- used as recognition system for self cells
- what helps prevent immune system attack SELF cells
What happens when nucleated cells become invaded w/ virus or become cancerous?
Class I MHC molecules alter
- body begins to attack altered MHC cells + destroys them
What are Class II MHC molecules?
- Restricted to immune cells
- antigen presenting cells
- B cells
- macrophages (phagocytes)
- once they engulf antigens, fragments of Class II MHC are put onto their surface
- immune system recognises them, + mounts an attack upon the cells that engulfed the antigens
What are the main antibodies
- IgA
- IgD
- IgG
- IgE
- IgM
IgG
- most common (75-80%)
- smallest
- easily escapes bloodstream into interstitial fluid
- antiviral, antitoxin, antibacterial
IgM
- 10% of circulating immunoglobulins
- found in intravascular pool, cannot penetrate capillary wall
- when we FIRST COME IN CONTACT w/ antigens = INITIAL RESPONSE
- Found on B-cell surfaces
- Activates complement system
IgA
- produced by plasma cells located in skin/mucous tissue
- found in saliva, tears, tracheobronchial secretions, GI tract
- prevents organisms from entering the body
- attacks them before they enter
- can be passed onto offspring via breast milk
IgD
- found on B cell membranes (w/ IgM)
- small amounts in blood
- thought to help stimulate b cells to multiply and differentiate into plasma and memory cells
- leads to secretion of IgM+G
(not 100% clear)
IgE
- provides immunity against parasites
- responsible for initiating inflammatory +; allergic reactions
- binds to receptors on basophil +; mast cells (leads to mast cell degranulation, release of histamine, trigger of inflammatory response)
What are the function of the 5 antibodies?
- Precipitation +; agglutination (bind w/ antibody to form complex, makes antigen larger to make easier to find by macrophages)
- Neutralization (of toxins released by antigens … spider/snake bites)
- Opsonization (coding of foreign antigens so that phagocytic cells can better recognize)
- Complement activation (activates inflammatory response to keep infection in localized area/prevent spread)
Immunoglobulins + antibodies are important as they help in diagnosing certain tests
(memorize)
What are some Diagnostic Tests?
- Titer/titre
- Indirect Coombs test
- Elisa
- MHC Typing
Titer/titre
Measures levels of serum immunoglobulins
Indirect Coombs test
Detects Rh blood incompatibility
Elisa
Detects for HIV antibodies
MHC typing
Tissue matching before transplant procedures
Which 2 antibodies also have a primary and secondary immune response?
IgM +; IgG
Primary Response
- First exposure to antigen (first encounter)
- 1/2 weeks for body to build efficacy (to rid body of antigen)
- (IgM kicks in first + quickly)
Secondary Response
- Next encounter of antigen
- Thanks to memory cells
- more rapid efficacy (1-3 days)
- lack of manifestation of invasion
- (IgG kicks in first + quickly)
What are the types of ADAPTIVE IMMUNITY
- Natural immunity (active/passive)
- Innate immunity (born with)
- Acquired immunity (active/passive)
Active Immunity
Body has done something to develop immunity on own
- Natural - natural exposure to antigen (getting chicken pox once…won’t get it again)
- Artificial - antigen purposely introduced to body (vaccine)
- — typically weakened or dead
Passive Immunity
- Natural: IgG from mother to child (placenta, breast milk),
- Artificial: injection of antibodies
both short term
