Week 5: Adaptive Immunity Flashcards
What is different about the adaptive immune system from innate?
Recognize slowly, distinguish between different types of pathogens
What are the three things special about the adaptive immune system?
It is specific, systemic, and has memory
What are the 5 phases of adaptive immune response?
- antigen recognition
- activation of lymphocytes (T/B)
- antigen elimination
- decline of effector cell function
- memory development
What are epitopes?
Small defined structures on antigens that bind to T/B cell antigen receptors
What are differences in what is recognized on antigen between B/T cells?
B = 3D structures on protein surfaces/complex carbs on pathogen
T = small peptides bound to MHC molecules
What are two differences between T/B cells?
T = cell membrane anchored, 1 recognition site
B = can be anchored or antibody molecule, 2 recognition sites
APCs are specialized _____ cells that are equipped to process _____ efficiently. What else can present antigens?
Immune, antigens. B cells and macrophages.
How do MHC I and MHC II processing of antigens differ?
MHC I: endogenous, vesicle undergoes exocytosis after digestion
MHC II: exogenous, phagocytosis, vesicle undergoes exocytosis
What are the 3 mechanisms to cell-mediated immunity?
- cytotoxic killing
- intracellular killing by macrophages
- tissue disruption/toxin secretion
What type of T cell are cytotoxic cells?
CD8
What do T helper cells support?
Inflammation, macrophage killing of bacteria
What do eosinophils do?
Produce enzymes & toxins that kill parasites that have infiltrated tissues
What do mast cells do?
Product enzymes, recruit neutrophils, helping tissue expel parasites
What are the 5 mechanisms of antibody-mediated immunity?
- neutralize soluble extracellular toxins/antigens
- prevent attachment
- immobilize bacteria (restrict cilia/flagella)
- enhance bacterial phagocytosis
- activate complement system
Which immunoglobin class is most abundant?
IgG. Order goes: GAMDE.
What is special about IgA and IgG?
Bound by receptors, transported across epithelium/placenta. Dimeric.
Define active natural immunity?
Adaptive immune response to infection.
Define passive natural immunity.
Transfer of antibodies from mother to fetus across placenta (IgG) and through breast milk (IgA)
