Chapter 15 Flashcards
Define immunocompetence
ability of human to mount a normal immune response
which immunity…
discriminate well between self and non-self
adaptive
which immunity…
acts indiscriminately
innate
which immunity…
made up of classes of identical cells
innate
which immunity…
enormous diversity that can recognize trillions of antigens
adaptive
which immunity…
same type of response to each pathogen
innate
which immunity…
is specific, unique resposne to each pathogen
adaptive
which immunity…
remembers previous exposures to antigens to mount stronger subsequent response
adaptive
which immunity…
has no memory of previous exposure
innate
what are two features of adaptive immunity
specificity
memory
define specificity with adaptive immunity
antibodies produced; function only against the antigen that they were produced in response to
Define memory with adaptive immunity
lymphocytes are programmed to “recall” their first encounter with an antigen and respond rapidly to subsequent encounters
adaptive immunity is the product of
dual system of B cells and T cells
define antigens
molecules that are recognized by T cells or B cells
What makes a good antigen
very specific interactions
antigens are complex molecules with
lipoproteins
lipopolysaccharides
nucleoproteins
What makes a poor antigen
small, simple molecule not attached to a carrier molecule and simply large molecules
Innate immunity takes care of
usual suspects
cells of adaptive immune system achieve high specificity and selectivity using a cell surface unique
to single antigen
by the time T and B cells reach lymphoid tissues each one is already equipped to respond to a single unique antigen…
what are the major functions of receptor
- recognize self vs nonself
- phagocytosis
- produce cytokines that function in cell signalling
it is accepted that there is a _________ lymphocyte receptor for each unique antigen
different
What is the clonal selection theory
undifferentiated lymphocytes in embryo and fetus undergo a continuous series of division and genetic changes that generate millions of different cell types, each with a particular unique receptor specificity
progency of B cell clone are called
plasma cells and memory b cells
progeny of T cell clone are called
CD8 cytotoxic t cells
what does the clonal selection theory imply
antigens activate lymphocytes by binding one specific receptor
once differentiated into clones, the cell can differentiate further into cells of the same type
What does self vs non self recognition come down to
cell surface receptors: cell surface receptors confer specificity and identity, allow for surveillance and recognition
Adaptive immunity relies on cell surfaces proteins encoded in the DNA region celled the
major histocompatibility complex
What does the major histocompatibility complex do
encodes a set of cell surface proteins essential for the acquired immune system in the recognition of self and in rejection of foreign molecules
Where are MHC molecules found on
all cells except RBC
the MHC is also known as the
human leukocyte antigen system
Define class 1 MHC
genes code for markers that display unique characterisitcs of self and allow recognition of self molecules and regulation of immune reactions
Define class 2 MHC
genes code for immune regulatory receptors found on antigen-presenting cells; macrophages, dendritic cells, and b cells
What do b cells do
production and actions of antibodies in response to the antigen
WHat do t cells do
responses to the APC
B cells have receptor proteins called _____ on the surface of their cells
antibody
B cell is __________ immune response
humoral
What does activation of b cells cause
b cell differentiation
plasma cells
antibody factories
b memory cells
long-lived cells capable of quickly producing more effector cells
b memory cells
long-lived cells capable of quickly producing more effector cells
B cells present the antigen on the surface of their cells, ___________ —> induce further cytokines production; cytokines produced by t cells help facilitate b cell differentiation
t cells recognize
When are b cells activated
when antibody binds to antigen
define antiserum
serum of blood containing specific antibodies
Define primary response
latent period with no measurable antibody occurs early on
Define secondary response
latent period is lacking because other memory lymphocytes from earlier response are immediately ready to react
T cells bind
MHC-2 receptors with an antigen
T cells are
cell mediated immune response
What do t cells do
release cytokines, can induce lysis or apoptosis, can stimulate b cell maturation
What do t cells target
abnormal cells
unlike b cells; t cell receptors are
small, not secreted
full maturation in the ______ _______ for t cells then migrated to the lymphoid organs
thymus gland
in most immune reactions, t cells will interact with an
antigen presenting cell
_____ _____ and _______ concentrate the antigens and circulate them so they will encounter lymphocytes
lymph nodes; spleen
What are examples of antigen presenting cells
dendritic cells
macrophages
b cells
t cell activation results after antigen presentation and involves a direct collaboration among an _______ and a _______
APC and t helper cell
What do CD8 cytotoxic t cells do
recognize MHC-2 adn antigens and target the cell for distruction
what do CD4 T helper cells do
recognize MHC 2 and antigen to trigger cytokine production
What do CD4 T memory cells do
stored in lymph nodes and protect against future encounters with same antigen
Define artificial immunity
acquired through medical procedure
define natural immunity
acquired as part of normal life experiences
define active immunity
results when a person develops their own immune response to an antigen that stimulates production of antibodies; creates memory cells, takes time, and is lasting
Define passive immunity
pre-formed antibodies are made by one idividual and donated to another individual; does not create memory acts immediately and is short term
