4.2 Adaptive Immune System Flashcards
Where are antigen-presenting cells found?
Skin
Mucous membranes
Lymphoid organs
Blood stream
Name the 4 types of antigen presenting cell
Dendritic cell
Langerhan’s cells
Macrophages
B cells
What do MHC and HLA stand for?
MHC= major histocompatibility complex HLA= human leukocyte antigen
What is a class I MHC?
Found in all nucleated cells and presents peptides from intracellular microbes (viruses).
Where do class 1 MHC molecules present to?
CD8+ T cells
What is a class 2 MHC?
Found in dendritic cells, macrophages and B cells and present peptides from extracellular microbes (bacteria)
Where do class 2 MHC molecules present to?
CD4+ T cells
What is the specificity for MHC molecules?
Very broad- many peptides can be presented by the same MHC molecule
When an intracellular microbe is presented to a CD8+ T cell, what response occurs?
Cytotoxic T cells move to the infected cell and destroy it
When an intracellular microbe is presented to a CD4+ T cell, what response occurs?
Cell-dependent immunity- B cells produce antibodies or macrophages will phagocytose the pathogen
When an extracellular microbe is presented to a CD4+ T cell, what response occurs?
Humoral immunity- involvement of neutrophils, eosinophils, B cells and mast cells
When does IgA get released into the body?
During mucosal immunity
When does IgM get released into the body?
Compliment activation
When does IgE get released into the body?
Helminth immunity or mast cells
When does IgG (opsonin) get released into the body?
Phagocytosis
Compliment activation
Neonatal immunity
Toxin/viral neutralisation
