Lumphocyte Receptors and B-Lymphocytes Flashcards
What cells are the major components of the adaptive immune system?
Lymphocytes!
What are the X2 board types of lymphocyte?
T-cells or lymphocytes
B-cells or lymphocytes
What is the structure of the T-cell receptor?
It is a heterodimer (X2 different chains)
= X1 alpha chain
= X2 beta chains
Each chain consists of a long constant region with a small tip called a variable region, the variable region being the antigen binding site.
What is the structure of the B-cell receptor?
It has X2 antigen binding sites as it is a Y-shaped structure comprised of:
= X2 heavy chains (long inside chains)
= X2 light chains (inner shorter chains)
Again the variable regions are found at the tip.
What is the main concept of adaptive immunity in terms of the number of cells with the specific receptor for that antigen?
When first in contact with an antigen, the cells divide to create larger pools of these cells in order to fight it. These remain as memory cells therefore if the same antigen is present again the number of quiescent memory cells allows for the antigen to be dealt with more rapidly next time.
What are the rough timings for the:
1) First exposure
2) Second exposure
1) 12 days
2) 5-7 days
What is the name of the process used by the body to ensure receptor diversity is achieved?
gene rearrangement
What X3 subdivisions make up the variable region of an antibody heavy chain of a B-cell split into?
What X2 subdivisions make up the variable region of an antibody light chain of a B-cell split into?
Heavy chain = variable, diversity and joining
Light chain = variable and joining (no diversity)
What are the X2 subdivisions of gene rearrangement?
1) combinatorial diversity (the random variations of possible combinations)
2) joining diversity (adding or removing extra nucleotides at the sections where the sections of the chains join)
Where are B-cells developed and where do they undergo gene rearrangement?
In the bone marrow (B for Bone)
Where are T-cells developed and where do they undergo gene rearrangement?
In the thymus (T for Thymus)
What happens when antigens bind to T-cell receptors?
They can become cytotoxic or helper T-cells.
What happens when antigens bind to B-cell receptors?
They differentiate to form plasma cells which produce antibodies of the same specificity as that on the B-cell for which they came.
What is another name for an antibody?
Immunoglobulin (Ig)
Which cells produce immunoglobulins?
Plasma cells (which are differentiated B-cells)
What X2 Greek letters can the antibody light chain be?
Kappa or lambda
What type of bonds connect the immunoglobulin heavy chains together and also the heavy chains to light chains?
Disulphide bonds.
Which Ig is found mostly in the serum?
Igg
Which Ig is found mostly in mast cells?
Which cells are Ige mediated and linked to histamine release?
Ige
Mast cells (basophils)
What are the X5 classes of Ig?
M A D G E