Crash Course in Immunology pt.2 Flashcards
Two major arms of adaptive immunity
Humoral and cellular
Humoral Immunity
antibodies produced by B cells
Attack extracellular pathogens
(Antibody=mediated immunity)
Cellular Immunity
T cell receptors target intracellular pathogens
Rejection of forgien tissue and deconstruction of tumor cells
(cell=mediated immunity)
Antigen
any substance that causes body to produce antibodies
Antibody
Immunoglobulins
proteins
2 identical antigen-binding sites
Each class of antibody
IgA
IgD
IgE
IgG
IgM
IgA
secreted into mucous, saliva, tears, colostrum
tags pathogens for destruction
IgD
B-cell receptor stimulates release of IgM
IgE
binds to most cells and basophils
Allergy and anti-parasitic activity
IgG
binds to phagocytes
main antibody for secondary responses
crosses placenta
IgM
fixes complement
Main antibody of primary response
B-cell receptor
Immune system memory
Major outcomes of an antigen-antibody interaction
Agglutination
Opsonization
Activation of Complement
Neutralization
Agglutination
reduces number of infectious units to be dealt with
Opsonization
coating antigen with antibody enhances phagocytosis
Activation of Complement
causes inflammation and cell lysis
Neutralization
blocks adhesion of bacteria and viruses to mucosa
blocks attachment of toxin
Primary Response in Humoral immunity
produced first time antigen encountered
- IgM first, declines
- IgG increases
Secondary Response in Humoral immunity
produced on subsequent antigen exposure
- IgM response same
- IgG response quicker and higher
- Memory response due to memory cells produced during primary response
T Cells
Recognize antigens presented by antigen-presenting cells that process antigen first
- dendritic cells and macrophages
Helper T cells (CD4 T cells)
secrete cytokines that activate other cells of immune system
- TH1 Helper cell
- TH2 Helper cell
Cytotoxic T cells (CD8 T cells)
target intracellular pathogens (viruses)
Lyse cell or induce apoptosis
Types of acquired immunity
Active immunity
Passive Immunity
Active Immunity
production of antibodies by body itself and development of memory cells
Natural:infection
Artificial: Vaccination
Passive Immunity
acquisition of antibodies from another
source memory cells not developed
Natural: maternal antibodies
Artificial: Monoclonal antibodies
TH1 Helper cells
activate macrophages to phagocytose and cytotoxin T cells to kill infected cells
TH2 Helper cells
stimulate B cells to proliferate and secrete more antibody
