Chapter 8.2 Flashcards
What are defensins
-they are antibacterial enzymes found on the skin
What are lysozomes
- they are produced by the tears and saliva
- >they are nonspecific bacterial enzymes
What is the purpose of the compliment system
- they punch holes in the wall of bacteria
- > making them osmotically unstable
-compliment pathway is nonspecific defense
What are the two types of complementary systems
1) Classic pathway
- >requires the binding of antibody to pathogen
2) Alternative pathway
- >does not require antibodies
What are interferons? Specifically what is their purpose?
- cells infected with viruses produces interferons
- > interferons are proteins that prevent viral replication and dispersion
- > they also tell cells nearby to decrease production of viral and cellular proteins
What is the relationship between interferons and MHC class molecules
- they result in upregulation of MHC class 1 and class 2 molecules
- > resulting in increased antigen presentation
-interferons are responsible for many flu like symptoms
How does the MHC work?
- it picks up little pieces of the invader from the macrophage(inside it)
- MHC binds to the pathogenic peptide(the antigen) and carries it to the cell surface
- > cells of the immune system then recognize this antigen at the top of the MHC
Describe the relationship between macrophages and cytokines
- macrophages release cytokines
- > cytokines are chemical substances that stimulate inflammation
- > they also recruit additional immune cells to the area
Do all nucleated cells in the body display MHC class 1 molecules
-yes they do
How would you tell if a cell that is infected based on MHC class 1?
- if the MHC presented an unfamiliar protein on the surface
- >a protein that the body did not recognize
What pathway is the MHC-1 pathway referred to as?
- it is referred to as the endogenous pathway
- >because it binds to antigens from inside the cell
Which cells are MHC class 2 molecules expressed by
-they are expressed by antigen-presenting cells like macrophages, dendritic cells in the skin, some B-cells and certain epithelial cells
What are pattern recognition receptors? What type of cells have pattern recognition receptors?
- they are able to recognize the category of the invader
- > eg; recognize if it is a virus, a bacteria or a fungus or a parasite
- > this allows for the production of the appropriate cytokines to recruit the immune cells
What is a natural killer cell
- it is a type of nonspecific lymphocyte
- > that is able to downregulate MHC
- > downregulation=apoptosis of virally infected cells
Describe how neutrophils work
- they are the most populous leukocyte in the blood
- > involved in non-specific defense
- > they are phagocytic
- > follow bacteria by CHEMOTAXIS
- > can also detect bacteria if it has been opsonized(marked with antibody from B cell)
