Adaptive/Acquired Immunity Flashcards
When is adaptive immunity mobilized?
After external barriers have been compromised and inflammation has been activated
What does adaptive immunity promote against?
reinfection
How does adaptive immunity differ from inflammation?
Inducible, Specific, Long-lived, and has memory
What is an antigen?
molecules on surface of microbes, infected cells, or abnormal tissues
What is the molecular target of antibodies?
antigens
What is an antibody?
blood protein produced in response to an antigen
What are the two types of lymphocytes?
T cells and B cells
Where are T cells derived?
thymus
Where are B cells derived?
Bone marrow
What are the two interrelated immune pathways?
Humoral and cell-mediated
What is the humoral immunity pathway?
antibodies are produced by B lymphocytes and target exogenous antigens; antibodies in blood; binds to antigens
What is the cellular/cell-mediated pathway?
Targets antigens directly, does NOT produce antibodies; defends against INTRACELLULAR pathogens and abnormal cells
In cellular immunity where are T cells located?
Blood and tissues
Are B-cells slow or fast to act?
slow
What must happen to B-cells for them to develop immunity?
exposure to pathogen: via environment or premeditated (i.e. vaccine)
What is a key difference between acquired and natural immunity regarding B-cells?
it has memory: once exposed, always protected and systemic
Where are B-lymphocytes made and matured?
bone marrow
What do B-lymphocytes develop?
immunocompetence
What is immunocompetence?
recognizing and binding to pathogens while ignoring body’s cells
What are membrane-bound antibodies?
displaying around 10,000 proteins on surface
Does each B-cell have unique membrane-bound antibodies?
yes
What is something to know about the unique membrane-bound antibodies?
The more unique antibodies, the more likely they are to match an antigen for recognition
Where do B-lymphocytes reside once they mature?
in the lymph nodes, lymph, and blood
When are B-lymphocytes truly activated?
exposed to perfect match
What do B-lymphocytes do when they are activated?
clones itself and produces more of the same cells for the specific antigen
Which cell is the majority and what do they do?
Effector/plasma cells: antibody production
What is important to know about Memory B cells?
long-lived, remember genetic code, produce stronger & faster response
What do antibodies do?
bind and mark for destruction
What is neutralization?
block binding sites so they can’t reproduce
What is agglutination?
multiple binding sites: antibodies can attach to multiple antigens at one and clump them together
What does agglutination do?
makes it easier for macrophages to destroy
What does sending out chemical messengers do?
attracts phagocytes and lymphocytes to destroy
What do frequently mutating pathogens do? What are some examples?
make memory cells ineffective; influenza, COVID
What are some examples of pathogens that do not mutate frequently?
mumps, polio
What is passive immunity?
pre-formed antibodies from mother via placenta or breastmilk
How can antibodies aid in immune response for another person? Examples?
person who has antibodies can give blood plasma to another person; COVID, ebola
What are the classes of immunoglobulins?
Ig: G, A, M, E, D
IgG
abundant, protective, placenta
IgA
blood
IgA-2
bodily secretions: helps attack pathogens before the blood stream
IgM
largest, first produced, neonatal
IgE
low concentration, parasitic infections: attracts eosinophils b/c of inflammatory reaction
What are IgE’s the common cause of?
allergies
What is cellular/cell-mediated immunity
Last effort to defend body; Natural and humoral have failed; cells breached by invaders
What are antigen-presenting cells (APC’s)?
phagocytes/macrophages engulf + break up antigens–> display pieces on exterior surface attached to MHC
What do Major Histocompatibility Complexes (MHC) do?
tells body’s immune system to leave them alone b/c they are fighting off infection
Where are T cells made and matured?
made: bone marrow
matured: thymus
How can do T cells recognize antigens?
In broken up form on MHC
What do helper T cells do?
can’t directly destroy, only bind to 1 specific combination, copy, releases cytokines
What are cytokines
chemical messengers
What do cytokines do?
multiply helper T cells, activate cytotoxic T cells, activate B cells
Can B cells bind to healthy cells?
Yes, can destroy
What does a B cell do once it is bound to an antigen?
waits for Helper T cell to inspect & release cytokines
What are cytotoxic cells?
locate cells, release enzymes that puncture cell membrane and kill, hunts for more
Where do cytotoxic cells reside?
blood and lymph
What are regulatory T cells?
release inhibitory cytokines, stop immune response
What disease has no regulatory T cells?
autoimmune: immune response never stops and kills healthy cells and tissues
