Host Defenses II Flashcards
what is the third line of defense
adaptive immune response
immunological memory
rapid immune response during secondary exposure
which cell is the cellular response
T cells
which cell is the humoral response
B cell
goal of the adaptive immune system
eliminate an identified pathogen and remember it for next time
immunogenicity
ability of an antigen to cause an immune response
epitopes
specific molecular pattern recognized by immune system
complete antigens examples
proteins
polysaccharides
lipids
incomplete antigens
small molecules
4 stages of adaptive immunity
- antigen presentation
- lymphocyte activation
- lymphocyte proliferation and differentiation
- antigen elimination and memory
what activates the B or T cell
binding
clonal expansion
proliferation
what are CD proteins
cluster of differentiation proteins
important CD proteins
CD4 (helper) and CD8 (cytotoxic)
T cytotoxic cells
destroy cells
T helper cells
release cytokines
B cells (plasma cells)
secrete antibodies
B cells (memory cells)
remember pathogen
what does MHC mean
major histocompatibility complex
what does the MHC do
present antigen to immune system
either class 1 or 2
MHC 1
on all cells except RBCs
unique to individuals
activate CD8 T cells
T cell activation
different signals lead to different cascades
T helper cell differentiation
depends on cytokine release from APCs
what are APCs
antigen presenting cells
effector T cells
cytotoxic destroys cells with antigen
helper cells recruit other leukocytes
how to T cytotoxic cells destroy cells
perforins and granzymes
what do perforins do
form holes
what do granzymes do
activate apoptosis
memory T cells
provide quick response to secondary exposure
both helper and cytotoxic cells
T regulatory cells
decrease immune response after infection
stages of humoral response
- B cells present antigens
- T-dependent B cell activation
- B cell proliferation and differentiation
- plasma cells release antibodies and memory cells go to lymphatic tissue
which MHC does the humoral response use
MHC 2
MHC 2 recognizes which antigens
extracellular
MHC 1 recognizes which antigens
intracellular
antibody monomeric structure
2 heavy chains
2 light chains
antigen-binding sites
what is an Ig
immunoglobulin
antibodies can
- neutralize
- activate compliment
- increase phagocytosis
types of antibodies to know
IgM, IgG, IgA
IgM percentage
10%
IgM function
first antibody
IgG percentage
80%
IgG function
predominant antibody
IgA percentage
10%
IgA function
protects mucous membranes
gene-shuffling
generates diverse repertoire of antigen receptors
how does the body not recognize itself
self-tolerance
how to build self-tolerance
cells screened prior to release
if they are self-identifying they are destroyed
immunological memory is conferred by
memory cells
antibody titer
amount of Ab present in blood
