adaptive immunity Flashcards
what is adaptive immunity consist of?
cell mediated responses and antibody (humoral) responses
adaptive immunity is carried out by which two cells?
B and T cells
which cell drives cell-mediated immunity?
T cell
cell-mediated immunity involves the activation of which cells?
macrophages, NK cells ad antigen-specific cytotoxic T cells
what is the key feature of adaptive immunity?
immunological memory - each pathogen is remembered by signature T cell or B cell receptor
how does adaptive immunity differ from innate in the number of genes required?
adaptive immunity requires several where as innate requires 1
name the 3 receptors involved in adaptive immunity?
- T cell receptor (TCR)
- B cell receptor (immunoglobulin [IgA])
- major histocompatibility complex (MHC protein)
T cells can be classified into two types, what are these?
- CD4+
- CD8+
which type of T cells are CD4+?
helper T cells
which type of T cells are CD8+?
Cytotoxic T cells
what is the CD antigen on T cells?
a cluster of differentiation cell surface markers involved in signalling
what are the 2 types of MHC molecules?
MHC class i and MHC class ii
what are MHC molecules?
cell surface markers involve din signalling
which cells contain MHC class i on their surface?
all nucleated cells
which cells contain MHC class ii on their surface?
antigen presenting cells, dendritic cells, macrophages, and B cells
CD4+ helps signalling through which molecule?
MHC class ii
CD8+ helps signalling through which molecule?
MHC class i
when CD is seen alone, it refers to which type of T cell?
CD8+ (cytotoxic)
what co-receptor is involved in the binding/activation to MHC class i?
CD8+
what co-receptor is involved in the binding/activation to MHC class ii?
CD4+
what co-receptor is involved in the binding/activation of both CD4+ and CD8+ T cells?
CD3
what are the 2 structural classes of T cell receptors?
alpha-beta T cells (most common) and gamma-delta T cells
describe the structure of a T cell receptor?
- can have either an alpha and beta chain or a gamma and delta chain
- has constant and variable region
- transmembrane region
which region of a T cell receptor determines variable binding?
variable region
how many gene segments encode the variable region of the alpha chain of a T cell receptor?
2 gene segments
how many gene segments encode the variable region of the Beta chain of a T cell receptor?
3 gene segments
which gene segments encode the variable region of the alpha chain?
- V (variable)
- J (joining)
which gene segments encode the variable region of the Beta chain?
- V (variable)
- J (joining)
- D (diversity)
where do B cells mature?
bone marrow
where are B cells found?
largely in lymphoid organs, also circulating blood and lymph
B cells recognise antigens through which molecule?
BCR
The B cell receptor is actually what immunological molecule?
the antibody
what happens to B cells once they are activated?
turn into plasma cells and churn out lots of antibodies against specific pathogens
what is another term for antibodies?
immunoglobulins
describe the structure of an immunoglobulin?
- 2 chains: heavy and light
- constant (bottom) and variable (top) region
- Y shape
- flexibility round tail
what are the 5 classes of antibodies?
- IgG
- IgE
- IgD
- IgM
- IgA
what is the main function of an antibody?
prevent microorganism adhesion, activation of complement, neutralise toxin, opsonisation to promote phagocytosis and destruction
heavy chain region of immunoglobulin involve the rearrangement of which gene segments?
- V (variable)
- D (diversity)
- J (joining)