Adaptive Immunity Flashcards
What are the characteristics of adaptive immunity?
Specifity, memory and tolerance
Major players in adaptive immunity
- Lymphoid tissue
- Antigen-presenting cells (APCs)
- Follicular dendritic cells
- T lymphocytes
- B lymphocytes
What do APCs do?
These cells display fragments of invading pathogens on their surface to other immune system cells, especially T lymphocytes
- fixed and free macrophages e.g. Kupffer cells
What are Kupffer cells an example of?
An APC
What proteins are used in antigen presentation?
Major histocompatibility complex proteins
What are MHCs?
Major histocompatibility complex proteins are glycoproteins present on the cell surface and bind antigens and ‘present’ them
Two types of MHCs
MHC I and MHC II
MHC I
- Found in all nucleated cells
- Constitutive
- Activates cytotoxic T cells
What actives cytotoxic T cells?
MHC I
MHC II
- Found in APCs
- Activates helper T cells
- Inducible in many cells
What activates helper T cells
MHC II
What does it mean when a T cell is naïve?
The T cell hasn’t met its pathogen it’s suited for yet
What do T helper cells activate/form?
Cytotoxic T cells and memory T cells
Proteins associated with cytotoxic T cells
Perforin
Lymphotoxin
What do cytotoxic T cells cause?
Apoptosis
What does perforin do?
Knock holes in cell membrane. Associated with cytotoxic T cells
What is lymphotoxin?
A tumour necrosis factor
Do memory T cells from reserves?
Yes
How do T cells, B cells and APCs travel?
Through lymphoid tissue
When would T cells, B cells and APCs leave lymphoid tissue?
On antigen presentation as they are attract by chemokines
How many types of immunoglobulin are there?
5
What are the types of immunoglobulin?
- IgG
- IgA
- IgM
- IgE
- IgD
Which immunoglobulin is the most common in the body?
IgA because it is secreted by mucous membranes
Which immunoglobulin is the most common in blood?
IgG
What is clonal expansion?
The production of daughter cells which originally arise from the same single cell
Clonal expansion for antigens
stem cell –> pre B cell –> immature naïve B cell –> mature naïve B cell –> memory B cell and plasma B cell –> produce antigens
Antibody-mediated death
Immunoglobulins bind to surface –> activate complement
What is myasthenia gravis?
Disorder which causes muscle weakness which comes and goes. Often affects the face
