L1 Overview of Immunology Flashcards
list 3 chemical barriers to infection
lysozyme
spermine
acid pH
list 2 physical barriers to infection
skin
mucous
what is innate immunity?
functions as the “first line” of defense to invading pathogens (antigens)
composed of cells and molecules that provide
RAPID
NO MEMORY
NO SPECIFICITY (non-specific)
cell types - dendritic cells, monocytes/macro, neutrophils/granulo, eosinophils, NK cells
what is adaptive immunity?
mediated by lymphocytes (B and T cells) whose antigen recognizing receptors are very specific
LAG TIME with first encounter
MEMORY
SPECIFICITY!
the first encounter with antigen, cells undergo differentiation to acquire effector function and then some of those become memory cells
define the term tolerance
means you tolerate self tissue, you don’t get an immune response to own tissue
what is the consequence of loss of tolerance?
autoimmunity
what is the role of primary lymphoid tissue?
tissues that serve as developmental sites for lymphocytes
what are 2 examples of primary lymphoid tissue?
bone marrow
thymus
what is the role of secondary lymphoid tissue?
tissues that serve as activation sites
what are 3 examples of secondary lymphoid tissue?
lymph nodes
spleen
mucosal-associated lymphoid tissue (MALT)
define antigenicity (antigen)?
substance that is recognized by lymphocytes
define immunogenicity (immunogen)
molecules that induce the activation of T cells or B cells
if antigens is carried via lymphatics, where is the initial site of adaptive immune response?
lymph node
if antigens are blood borne, where is the initial site of adaptive immune response?
spleen
if antigens enter via mucosal tissue, where is the initial site of adaptive immune response?
MALT
what is the role of the immune system in host defense?
provides defense against foreign antigens
why is “self tolerance” essential to good health?
to fight off foreign pathogens
and to protect tissues of self
describe hematopoeisis
blood cells production with pluripotent stem cells
why is one molecule more immunogenic than the other? aka the 3 properties of antigens?
characterized by
- complexity
- higher molecular weight
- foreignness
proteins > polysaccharides > nucleic acids > lipids
what is a lysozyme?
present in secretions, splits the cell wall of gram positive bacteria
what is spermine
in semen
prevents the growth of gram positive bacteria
what does the acid pH in stomach prevent?
colonization of bacteria
what are soluble molecules produced by cells of innate immunity?
cytokines and chemokines
what cells in innate immunity engulf pathogens and degrade them?
dendritic cells
monocytes/macrophages
neutrophils/granulocytes
what cells in innate immunity present pieces of pathogens to T cells?
dendritic cells
macrophages
what cells in innate immunity secrete molecules that destroy pathogens?
eosinophils
NK cells
what are the cell types involved in adaptive immunity?
CD4+ T cells
B cells
CD8+ T cells
what systems and molecules are in innate immunity?
complement
cytokines
armamentrium from cells
what molecules are involved in adaptive immunity?
cytokines
antibodies
armamentarium
how does the body distinguish self from non self?
recognition
where does central tolerance occur?
bone marrow and thymus
where does peripheral tolerance occur?
outside of bone marrow and thymus…
what is an antigenic determinant/determinants/epitope?
unique region of the antigen that B cell and T cells recognize
hapten + carrier protein =?
epitope! covalently bonded?
what are cells that secrete cytokines (CD4+ T cells)?
Thp Th0 Th1 Th2 Th17
what are cells that secrete molecules that destroy pathogens?
mature cytotoxic cells (CTL)
what are cells that regulate responses (CD4+ T cells)
n Tregs
a/i Tregs
what is recognition?
distinguishing self from non self
what is recognition?
distinguishing self from non self
what is the allergy to drug metabolite?
haptens - acts like an epitope
what is the allergy to drug metabolite?
haptens - acts like an epitope
where was B cell maturation shown to occur in the chicken? What term was given to the human equivalent?
Bursa of fabricius
bursa equivalent
what is the fundamental event in B cell development? Why?
expression of a unique B cell antigen receptor (antibody) on its cell surface
receptor is instrument by which B cells will recognize antigen
what is the structure of the thymus
bi-lobed
each lobe is divided into lobules
each lobules has a cortex and medulla
what is the role of the blood thymus barrier
prevents the passage of molecules form the blood to the thymic cortex
blood vessels of the thymic medulla don’t have a barrier
what is the role of positive selection?
the cells of thymic maturation that survive the selection process
what is the role of negative selection?
during thymic maturation, selection of developing T cells undergo death by neglect
what is the role of positive selection?
the cells of thymic maturation that survive the selection process
what is the different between GALT, MALT and BALT
GALT - gut/ GI associated…= peyers patches
MALT - mucosal associated…
BALT - bronchus associated…
what is the role of M cells
where microbes enter MALT to reach the underlying lamina propria which is the site of follicles and immune cells like phagocytic cells, dendritic cells and lymphocytes!
what is the role of follicle associated epithelium
region where there is no goblet cells in GALT
what is the role of primary follicles
contain mature resting B cells
no germinal centers
what is the role of secondary follicles
germinal centers
antigen-activated B cells
what is the role of white pulp
contains the majority of lymphoid cells
whats the difference between a chemokine and a cytokine?
chemokine - induce leukocyte accumulation in tissues sites of inflammation
cytokines - secreted by activated leukocytes
what is a T dependent antigen
B cell activation occurs only in the presence of T cell cytokines and cognate interaction with activated T cells
what is a T independent antigen?
B cells that do not require cognate interaction with T cells
what is a monoclonal activator
activators of lymphocytes that activate a single clone
what is a oligoclonal ?
activators of lymphocytes that activate more than 1 clone but not all
what is polyclonal?
activators of lymphocytes that activate most or all clones
