Ingham-1: B and T cells, Abs Flashcards
2 branches/parts of the adaptive immune system
Humoral and Cell-mediated
Which lymphocyte is responsible for humoral immunity?
B cell
Which lymphocyte is responsible for cell-mediated immunity?
T cell
What is a B cell antigen?
substance that binds Ab
What is a B cell antigen made of?
protein, carbohydrate or DNA
What is an epitope?
Portion of Ag recognized by Ab
What is polyclonal antisera?
collection of diff. Abs from serum that recognize diff. epitopes of the same Ag
What are monoclonal Abs?
Ab derived from a single B cell clone (all recognize the same epitope)
What 2 chains make up Ab? How many of each?
- heavy and light
- 2
What holds heavy and light chains together?
disulfide bonds
How many light chain genes do mice and humans have?
2
What are the 2 light chain genes called?
kappa and alpha
How many light chain alleles do mice and humans have?
4
How many heavy chain genes do mice and humans have?
1
How many heavy chain alleles do mice and humans have?
2
What are the 5 isotypes of heavy chains?
IgA, IgD, IgD, IgE, and IgM
What regions of the Ab bind Ag?
variable regions of heavy and light chains
Which chains have constant regions (heavy or light)?
both
What is the function heavy chain C-terminal constant region?
effector functions
What regions of the chains form Ig domain fold?
VH/VL and CH/CL (the ones that are covalently joined together)
What is the structure of Ig fold?
2 beta sheets forming a beta sandwich
What does CDR stand for?
complementary determining region
In terms of CDR, what forms the Ag-binding site? (for BCR)
CDRs of heavy and light chains
For TCR, what forms Ag-binding site (in terms of CDR)?
CDRs of alpha and beta chains
What loops in VH and VL connect beta strands?
CDRs
What does a modular receptor mean?
Has a signalling subunit and an Ag-binding subunit
What does ITAM stand for?
Immunoreceptor Tyrosine-Based Activation Motif
What is alpha chain equivalent in BCR?
light chain
What is beta chain equivalent in BCR?
heavy chain
What is signalling subunit of TCR?
CD3
Isotypes differ with respect to ___ and ___ of Ig domain
sequence, number
Different isotype Fc (constant) region have different ___
functionalities
Which isotype activates classical complement pathway?
IgG and IgM
Which isotype crosses placenta?
IgG
Which isotype binds to Fc receptors of phagocytes?
All except IgD and IgE
Which isotype performs mucosal transport via poly-Ig receptor?
IgA, IgM
Which isotype induces mast cell/basophil degranulation?
IgE
Which isotypes are present on membrane of mature naive B cells?
IgM and IgD
