CBG 26 (b) Flashcards
what does the adaptive immune system result in?
Results in memory =
Protection against re-infection with the same pathogen
Specific to a particular antigen – detected by specific receptors on T and B cells
Response improves with time
what is the adaptive immune system present in?
vertebrates (earliest =lamprey)
WHAT DID JACQUES MILLER DISCOVER?
the thymus produces T cells just around the corner on the Fulham Road
Function of thymus was previously unknown
what do b cells produce and what if this sometimes called?
antibodies
humoral immunity
how does a B cell become an antibody?
b cell receptor bind to antigen activated by antigen and helper t cells differentiation plasma cells ANTIBODY
T cells? what do the yrecognise an antigen as?
Have t cell receptors that are very picky.
They only recognise a foreign antigen as a peptide on an an MHC molecule presented by an antigen presenting cell (APC)
where are t an b cells produced? where are responses initiated?
T cells produced in Thymus B cells produced in bone marrowT and B cell responses are initiated in secondary lymphoid organs - lymph nodes and spleen
overall adaptive immunity components versus innate:
innate-epithelial barriers,phagocytes,complement,NK cells
adaptive b lymphocytes-> antibodies
T lymphocytes -> effector t cells
what type of response are b lymphocytes involved in?
Antibody-Mediated Immunity
Involves B lymphocytes, plasma cells and antibodies
what does cell mediated immunity involve?
T lymphocytes, antigen-presenting cells and MHC (major histocompatibility complex) molecules
Cellular immunity
what 2 types of ADAPTIVE immune responses are there?
antibody-mediated immunity
cell-mediated immunity
what do t cells differentiate to?
effector cells following antigen presntation by APCs and activate b lymphocytes
What 3 types of t cells are there?
helper
cytotoxic
regulatory T cells
are antigens only peptides?
although primarily peptides, Carbohydrates, nucleic acids and lipids are also
potential antigens
epitope?
are sites within
antigens to which antigen
receptors bind
antigens?
the molecules
recognized by the immune
response
how do antibodies work?
bind to epitopes on surface of antigen
epitopes recognized by receptors are often buried
antigen must first be broken down to peptide fragments
the epitope binds to the self molecule (MHC molecule)
t-cel receptor binds to a comple of MHC and epitope peptide
Describe the properties of antibodies?
-glycoproteins
-monomers/dimer/pentamers
-4 polypeptide chains:
-2 identical light
-2 identical heavy
variable and constant regions of heavy and light chains
what is immunoglobin
Antigen binding molecules of B cells i.e. B cell antigen receptors
how are the five antibody classes (isotypes) classed and what are they?
IgA, IgG, IgM, IgD, IgE
Based on structural differences in Constant regions of heavy chains.Each Class has specialized effector functions
what type of responses are those of T and B cells?
clonal :
B lymphocytes recognize intact pathogenic microorganisms and toxins
B lymphocytes possess specific surface receptors for recognition of specific antigen
IgM and IgD default
Binding of specific antigen results in proliferation of a clonal population of cells
Antigen determines clonal proliferation
what are APC’s?
Antigen presenting cells (APC’s)
Macrophages & Dendritic cells
(T lymphocytes respond to antigens on the surface of antigen presenting cells )
t cell maturation + post?
Maturation takes place in thymus gland followed by migration to secondary lymphoid tissue
IGa GOOD/
CROSSING EPITHELIAL CELLS
igE
good at killing parasites
