3- Principles of Adaptive Immunity Flashcards
What is the main difference between innate and adaptive immunity?
Innate is non-specific with no memory, and adaptive is slow and creates a memory using B and T cells.
What is an antigen (Ag)?
A particle that has a specific sequence to which an immunoglobulin or T-cell receptor can bind to.
What is an antigen receptor?
Receptors that bind antigens. They are either immunoglobulins or T-cell receptors.
What are B cell receptors?
Immunoglobulins on the outside of the B cell to which bind matching antigens.
What are T cell receptors?
Receptors on the surface of T cells which bind to specific antigens.
Which region of the immunoglobulin (Ig) molecule binds the antigen?
The variable region- there is a different sequence for each Ig
Which gene segments code the variable regions of the heavy and beta chain?
V, D and J
Which gene segments code the variable region of the light and alpha chain?
V and J
What is the purpose of the V, D and J segments?
They create the diversity in the Ag receptor binding site!
What is clonal selection?
Multiplying the specific lymphocytes for a pathogen so that we can have an effective defense for that pathogen in the future.
Which cells carry the antigen to the naive T cells to bind to the TCR?
Dendritic cells
How are pathogen Ag’s delivered to the lymph node for the adaptive immune response?
Dendritic cells carry the Ag’s on MHC-II’s to the lymph node and wait for the corresponding T cell.
What are the Major Histocompatibility Complexes (MHC)?
They are molecules in every nucleated cell that present antigens to T cells.
Which class of MHC recognizes intracellular pathogens?
MHC-I
Which class of MHC recognizes extracellular pathogens?
MHC-II
What type of T cell corresponds to MHC-I’s?
CD8 Tc cells
What type of T cells correspond to the MHC-II’s?
CD4 Th cells
What cells have MHC-I molecules?
All nucleated cells. Basically everything except RBC’s (don’t have a nucleus).
What cells have MHC-II molecules?
Professional antigen-presenting cells (APC’s_. These are dendritic cells, macrophages and B cells.
What are the 5 Ig molecules?
IgA, IgD, IgE, IgG, and IgM. (GAMED)
Which 2 Ig’s are on the B cell surface?
IgD and IgM
What is the first antibody (Ab) to be secreted in an immune response?
IgM
What are the 3 Ab’s that float around in the blood/lymph?
IgM, IgA and IgG
What is neutralization?
It’s when Ab’s bind tightly to an important site on a pathogen and stop its ability to grow and infect.
