Innate Immunity Flashcards
Phagocytosis must be preceded by
a. antigen binding to the phagocyte.
b. chemotaxis.
c. extravasation.
d. integrin binding to Ig superfamily CAMs.
e. oxidative burst.
a. antigen binding to the phagocyte.
Phagocytes bind antigen using receptors for
a. C5a.
b. chemokines.
c. glucose.
d. LPS.
e. selectins.
d. LPS.
Pathogens engulfed by macrophages
a. are completely degraded by hydrolytic enzymes into their component amino acids and sugars.
b. are degraded to small peptides and carbohydrates which are presented on Class I MHC to Tc.
c. may survive and replicate in the macrophage phagocytic vesicles.
d. stimulate macrophages to adhere to B cells.
e. stimulate vascular endothelium to upregulate selectin expression..
c. may survive and replicate in the macrophage phagocytic vesicles.
An inflammatory response
a. is characterized by a decrease in vascular permeability.
b. is stimulated by cytokines produced by neutrophils.
c. occurs only during a secondary response.
d. recruits phagocytes to the infection site.
e. usually lasts for many weeks to ensure antigen is completely removed
d. recruits phagocytes to the infection site.
Natural Killer cells
a. are stimulated to kill infected host cells via carbohydrate-binding receptors.
b. kill normal host cells with high levels of membrane MHC Class I.
c. kill virus-infected cells when the virus is acquired naturally but not by immunization.
d . recognize virus-infected cells by the presence of viral peptide on MHC Class II.
e. secrete the complement MAC to lyse virus-infected cells.
a. are stimulated to kill infected host cells via carbohydrate-binding receptors.
Interferons a and b do NOT
a. activate NK cells to kill virus-infected cells.
b. get synthesized by virus-infected cells in response to infection.
c. induce macrophages to increase expression of Class II MHC.
d. inhibit virus replication in infected cells.
e. stimulate expression of molecules required for Class I MHC presentation of viral proteins.
c. induce macrophages to increase expression of Class II MHC.
Immune system cell adhesion molecules do NOT
a. allow macrophages to leave the circulation.
b. allow T cells to home specifically to peripheral or mucosal lymphoid tissue.
c. attract leukocytes to an infection site.
d. help cytotoxic T cells to bind to their targets.
e. signal neutrophils that they have arrived at an infection site.
c. attract leukocytes to an infection site.
Early induced immune responses are like adaptive immunity in that they
a. are antigen-specific
b. demonstrate immune memory.
c. involve macrophages and complement.
d. involve T and B lymphocytes
e. use pre-synthesized proteins which can be released quickly upon cell activation.
c. involve macrophages and complement.
Selectins
a. are present on both leukocytes and vascular endothelial cells.
b. bind Ig-like vascular addressins.
c. include ICAM, VCAM, and MAdCAM.
d. select antigen-specific lymphocytes to extravasate into the infection site.
e. select antigen-specific macrophages to extravasate into the infection site.
a. are present on both leukocytes and vascular endothelial cells.
Lymphocyte recirculation
a. activates inflammatory cytokines to promote antigen presentation to T cells.
b. allows B cells to go to the site of infection to produce antibody.
c. circulates lymphokines efficiently throughout the body.
d. occurs for both naïve and effector lymphocytes
e. only occurs during an infection.
d. occurs for both naïve and effector lymphocytes
Phagocytes kill bacteria using all of the following EXCEPT
a. H2O2.
b. hydrolytic enzymes.
c. low pH
d. lysozyme.
e. strong reducing agents.
e. strong reducing agents.
For a circulating neutrophil to reach the site of inflammation, it must bind to blood vessel endothelial cell and then pass between the endothelial cells in a process called
a. addressinazition.
b. chemotaxis.
c. extravasation.
d. marginalization.
e. opsonization.
c. extravasation.
Macrophages are attracted to the site of infection by all of the following EXCEPT
a. bacterial peptides.
b. chemokines.
c. C5a.
d. IL-8.
e. MAdCAM.
e. MAdCAM.
Inflammatory cytokines produced by macrophages activate all of the following EXCEPT
a. B cells to secrete acute phase proteins.
b. integrin on leukocytes to bind more strongly to vascular CAMs.
c. neutrophils to be more cytotoxic.
d. NK cells to kill virus-infected cells.
e. vascular endothelium to increase expression of CAMs.
a. B cells to secrete acute phase proteins.
