Adaptive Immunity 2 Flashcards
(23 cards)
What are B cells? (Functions)
Facilitate communication with T cells
Produce antibodies
What process leads to B cell subset generation?
Clonal expantion
Name the 2 subsets of B cells?
Plasma cells
Memory B cells
Where do B cells mature?
Bone marrow
How do B cells recognise antigens?
Via B cell receptor - BCR (IgM or IgD)
Name the 5 different immunoglobulins produced by B cells?
Detail the common structure of a BCR (immunoglobulin)?
What feature during development generates BCR diversity?
Rearrangement of heavy and light chain genes
Summarise the development process of B cells?
Where dose negative selection of B cells occur?
in the bone marrow
What are the functions of the antibody produced by B cell?
-Neutralization
-Opsonization
Antibody-dependent cellular
cytotoxicity (ADCC)
Mast cell degranulation
-Initiation of complement
What are the 2 types of B cell activation
Thymus-dependent
Thymus-independent
What thymus-dependent B cell activation required?
Requires: Co-stimulatory molecules (CD40-CD40L) and Cytokine responses from TH2 cells
Result: differentiation into memory B cells & plasma cells
What stimulate thymus-independent B cell activation?
Through microbial antigens (e.g., LPS)
What result from thymus-independent B cell activation?
Differentiation to plasma cells
Activation leads to ?
Class switching occurs in mature B cells
What is affinity?
Strength of binding of single antibody to antigen
IgG, IgD and IgE have high affinity
What is avidity?
Ability of antibodies to form complexes (valency)
IgA and IgM have high avidity
What is the first antibody produced after B cell activation?
IgM
What are the 2 main types of immunological tolerance?
Central – In the primary lymphoid organs (the thymus and bone-marrow)
Peripheral – Tolerance occurring outside primary organs (e.g., lymph nodes)
What might happen if tolerance mechanism failed?
Autoimmune disease
What a breach of tolerance can lead to?
Autoimmune diseases
Peripheral Tolerance (B cells)
Complimentary, self-reactive T cells no longer present to stimulate B cell activity → Become anergic
