Ch 43 pt 2 Flashcards
Describe activation of B cells (6)
1) Helper T cells activated by macrophage antigen-presenting cells (via cytokines)
2) antigen binds to receptors on surface of b cell
3) B cell takes some antigens in by receptor-mediated endocytosis
4) Class II MCH protein of B cell presents antigen to helper T cells
5) activated helper T cells recognize the antigen and release cytokines that activate B cells
6) activated B cells divide to produce plasma cells and memory B cells
Every ________ has multiple _______
antibody; epitopes
How do antibodies deal with pathogens?
they mark pathogens for inactivation or destruction, they don’t kill them
explain the antibody function of neutralization (2)
1) Antibodies bind to viral surface proteins which prevent infection of a host cell
2) Antibodies can also bind to toxins preventing them from entering body cells
explain the antibody function of opsonization (2)
1) antibodies bind to antigens on bacteria, which leads to phagocytosis
2) enhances antigen presentation and humoral immunity (positive feedback)
Explain antigen-antibody complexes (2)
1) The complex binds to complement proteins which triggers activation cascade of complement proteins
2) ultimately forms a membrane attack complex
Explain the antibody function of agglutination (3)
1) Antibodies bind to antigen
2) 2 binding sites allow clumping of multiple antigens
3) phagocytosis
explain the antibody function of precipitation (3)
1) Antibodies bind to DISSOLVED antigen
2) 2 binding sites allow clumping of multiple
3) phagocytosis
What are the 5 different types of Ig in B cells?
1) IgD (membrane bound)
2) IgA
3) IgE
4) IgG
5) IgM
2-5 soluble
Explain cytotoxic T cell activation (8)
1) infected cell picks up part of virus
2) antigen presented on class I MHC in an endosome via exocytosis
3) CD8 on cytotoxic T cell helps it recognize the class I MHC
4) cytokines from helper T cell confirms foreign
5) Interleukin 2 from helper T cell activates cytotoxic T cell stimulating proliferation
6) army of specialized helper T cells and cytotoxic T cells go out and eliminate threats
7) vesicles contain perforins that create channels in infected cell allowing water to rush in
8) infected cell bursts (lysis)
What is the basis for immunization?
projection by the second immune response
What is immunization carried out by?
vaccines
What are the 2 types of immunity in immunization?
1) active immunity
2) passive immunity
When does active immunity develop?
it develops naturally when a pathogen invades
What are 2 examples of passive immunity?
1) IgG from mother to fetus via placenta
2) IgA from mother to infant via breast milk
What is artificial passive immunity?
antibodies from immune animal injected into nonimmune animal
What are monoclonal antibodies?
Antibodies prepared from a single clone grown in culture
- These antibodies are specific for one epitope
Explain the complications of immune rejection
complicates blood transfusions and tissue/organ transplants
What are the 2 ways to work around immune rejection in transplants?
1) surgeons use donor with similar MHC molecules to the patient to minimize rejection
2) patients take medicine to reduce immune response
What are the 4 blood groups?
A: A-antigen
B: B-antigen
AB: both antigens
O: neither antigens
What are allergies?
Allergies are exagerated (hypersensitive) responses to antigens called allergens
Explain allergies (6)
1) IgE antibodies produced to an allergen attach to receptors on mast cells
2) the next time allergen enters the body it’ll bind to mast-cell-associated IgE molecules
3) Mast cells release histamine and other inflammatory chemicals
4) allergy symptoms stimulated
5) acute allergic reaction may lead to anaphylactic shock
6) injection of epinephrine can counteract allergic response
What happens when one gets an autoimmune disease?
Immune system loses self tolerance
What are the 4 types of autoimmune diseases?
1) lupus erythematosus
2) rheumatoid arthritis
3) insulin dependent diabetes milletus
4) multiple sclerosis
What are the 3 physicals that affect the immune system?
1) exercise
2) physiological stress
3) sufficient rest
What are the 2 ways antigens variate?
1) change epitope expression
ex) human infuenza virus
2) Human viruses may exchange genes with virus of domestic animals
ex) corona virus
What is latency?
When a virus remains in host in inactive state
ex) herpes simplex virus
What is HIV?
Human Immunodeficiency virus
1) infects T cells
2) able to persist in host because of mutations
3) able to abolish adaptive immune response
4) leads to acquired immunodeficiency syndrome (AIDS)
What does AIDS do?
Makes people highly susceptible to infections and cancer
What are the characteristics of cancer?
Frequency increases when adaptive immunity is inactivated
Immune system can defend against viruses that cause cancer and cancer cells that have viruses
Which virus has a vaccine?
HPV (papillomavirus); causes cervical cancer
