Innate and Adaptive Immunity Flashcards
Innate Immunity
the initial phase of host response to infection, present in all individuals, which does not increase or change with repeated exposure to a given pathogen
Adaptive immunity
response of antigen-specific lymphocytes to antigen. Also known as acquired immunity. Confers life-long protection against reinfection by the same pathogen
Granulocytes
also known as polymorphonuclear leukocytes, general name for cells including neutrophils, eosinophils, basophils and mast cells.
Macrophage
- antigen presentation
- phagocytosis
- activation of bactericidal mechanisms.
Neutrophils
most numerous of the phagocytic cells, important in innate immune responses, phagocytosis and activation of bactericidal mechanisms. Have a horseshoe, lobular nuclear shape.
Eosinophils
important in killing of antibody-coated parasites. When activated they release granules containing a variety of enzymes and toxic proteins.
Basophils
function similarly to eosinophils.
Mast cells
release granules containing histamine and other active agents.
Dendritic cells
degrade pathogens they take up, but their main role is to present antigens to T-lymphocytes.
T-cell
subset of lymphocytes that develop in the thymus and function in a number of regulatory roles associated with B-cell production of antibody, macrophage activation or killing of cells infected with viruses and other intracellular pathogens
B-cell
upon activation these cells differentiate into an antibody producing cells called plasma cells.
MALT
mucosa-associated lymphoid tissue that serves a number of barrier and other functions in the immune response. Types of MALT include the GALT (gut), NALT (nasopharynx) and BALT (bronchus) associated lymphoid tissues.
Antibody
Protein (immunoglobulin) produced by activated B-cells that recognizes specific aspects of antigens (called epitopes). Integral component of the adaptive immune response.
MHC Type I
Genes that encode molecules that display peptides synthesized in the cytosol from viral infections on cell surface
MHC Type II
Genes that encode molecules that display peptides from bacterial proteins in intracellular vesicles on cell surface
Cystatins, Mucins, Statherins, Histatins, Defensins
anti-bacterial proteins/peptides found in saliva that act to clear potential pathogens our of the oral cavity. Some are also produced by epithelial cells, neutrophils and Paneth cells in the gut.
What are the cells of the adaptive immune system?
B and T cells
What are the different types of infectious agents?
Viruses, bacteria, protozoa, fungi, worms
Role of mucins and saliva in host defense
They provide a protective barrier to the epithelium and contain antimicrobial peptides
Clonal selection of B and T cells
Once these cells interact with antigen, the cell that has the correct antigen will undergo clonal expansion where it makes million of copies of itself
Antigen presenting cells
Macrophages, dendritic cells, B cells
What cells do APC’s present to?
T cells
