Immunology Lecture 12. Flashcards
What is the primary local immune response?
IgA
What is the primary serum antibody response?
IgG
How are microorganisms destroyed?
phagocytic cell
What type of cell is killed by a cytotoxic t cell?
infected host cells
What are the 6 types of innate immunity?
skin, pH barrier, flushing (ciliary action/flushing urinary tract), lysozyme (tears, nasal secretions, saliva), phagocytes, complement (lead to opsonization/lysis)
What is the primary adaptive immune response to bacteria?
antibody
How does strep. pneumonia evade immune response?
presence of antiphagocytic capsule
How does staph. aureus evade immune response?
has protein A which binds and blocks the opsonizing actin of IgG
How does salmonella typhus evade immunes response?
has ability to survive acid environment of the stomach
How does antibody protect the host?
prevents attachment to epithelium (IgA); triggers complement, binds to capsules acting as opsonin, neutralize toxins
How do we kill facultative intracellular parasites?
antibody won’t work - need activated macrophages (T-helper 1 response) = nonspecific response
What organisms can only be killed by the activated macrophage?
listeria monocytogenes (listeriosis), mycobacterium tuberculosis (TB), mycobacterium lepra (leprosy)
Why will the TH2 response not help with facultative intracellular parasites?
TH2 will help the organism get inside the cells where it will flourish
How is a macrophage activated?
by TH1 cell: CD40/CD40L and IFN-gamma
What is the TH1 response? What is released by TH1 cells?
cell mediated immunity: IL-2, IFN-y, TNF-a
What is the TH2 response? What is released by TH2 cells?
antibody production: IL4, IL5, IL-10, TGF-B
What is released by CD8 cells?
perforin, granzymes, granulysin
What does IL-2 do?
induces T-cell proliferation
What does TNF-a do?
activates endothelium to induce macrophage adhesion and exit blood vessel
What do CD40 and IFN-y do?
activate macrophage to destroy engulfed bacteria
What is the most importnat for clearance of parasites?
T cell response (activation of macrophages, CD8 cells), also eosinophils
What mechanisms do parasites use to escape the immune response?
inaccessibility (hide in host cell); avoidance of recognition (vary antigen expression, pick up host antigen); immunosuppression
How is antibody used in antiviral immunity?
neutralize the virus - binds to a portion of virus required for adsorption, penetration, uncoating, or replication
Which Ig is most important in antiviral immunity?
IgA - esp in respiratory, GI, genitourinary (local response)
What is the issue with antibody vaccines?
antibody prevents viral infection but once a virus infects a cell, antibody can’t kill the virus - need cell mediated cytotoxicity ONLY PREVENT
IL-2
drives proliferation and differentiation of virus specific T cells (comes from both CD8 and CD4)
