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MMBIO 261 Exam 1 (FINALS REVIEWING)

Terms in this set (57)

what is a characteristic of innate immune system?
fast
what is an example of how the innate immune system differentiates between self and non-self?
toll-like receptor 8 binds CpG DNA
what cell type produce type 1 interferon?
T cells
What is a cytokine?
molecule that cells use to communicate
which cell is good at phagocytosis but is not considered an antigen-presenting cell?
natural killer cell
what is the function of B cells?
make antibodies and present antigen to T cells
what is meant by clonal expansion?
a particular lymphocyte binds to an antigen, causing it to repeatedly divide
what is meant by specificity of an immune response?
each T or B cell will only be activated by one antigen
how is the immune memory maintained?
after an infection, memory cells specific for pathogen are maintained
what is the second signal for B cell activation?
CD40-CD40L
what is a point of contact between the adaptive and innate immune systems?
complement receptors on B cells, macrophages presenting antigens to T cells, antibodies activating complement, and pattern-recognition molecules on macrophages promoting activation of T cells
what is main function of B-2 B cell?
make antibodies
what is effector B cell called?
plasma cell
what is a T-independent antigen?
a repetitive chunk of bacterial cell wall with complement bound to it
which part of antibody recognizes an antigen?
Fab
where can IgA usually be found?
secretions
what is the difference between affinity and avidity?
affinity is strength of a single binding site and avidity is strength of the whole complex including multiple binding sites
what coreceptor is found on helper T cells?
CD4
what coreceptor is found on killer T cells?
CD8
what molecule actually sends the signal when the T cell receptor binds antigen?
CD3
If a T cell in the thymus binds to MHC and dies as a result, this is an example of which selection?
negative selection
what is the second signal for T cell activation?
B7/CD28
what is the primary cytokine that is characteristic of Th1 cells?
IFN-gamma
how can antigen-presenting cells control T cell activation?
presenting antigen on MHC, regulation of B7 on cell surface, and internalizing antigens and processing them for presentation
why would having too few MHC alleles in a population cause increased susceptibility to certain diseases?
since every MHC allele binds a slightly different peptide, you would be limiting the number of pathogens that could be bound effectively
where are MHC class I peptides loaded onto the MHC?
endoplasmic reticulum
what type of MHC and antigen do helper T cells recognize?
MHC class I, external antigens
what can hold longer peptides?
MHC class II
what would happen if a virus inhibited the function of the proteasome?
proteins could no longer be cut into peptides for MHC class I presentation
what is cross-presentation?
external antigens end up on MHC class 1
what cell types are primarily involved in granuloma formation?
macrophages and Th1 cells
what cytokine activates macrophages so they can kill bacteria more effectively?
interferon-gamma
what is the primary purpose of perforin?
allowing granzyme B into the cell
which of the following inhibits inflammation?
IL-10
what do killer T cells need to be fully activated?
IL-2 from helper T cells
what is the main determinant of whether a natural killer cell will kill a cell or not?
absence or presence of MHC class I
what is the sequence of events in combating a viral infection?
interferon, natural killer cells, killer T cells
what is the primary lymphoid tissue for T cells?
thymus
what happens if the process of making a B cell receptor fails to generate a heavy chain on the first try?
the cell tries again with the gene on the other homologous chromosome
how does the adaptive immune system distinguish self-antigens from foreign antigens?
all cells that recognize self-antigens are eliminated or inactivated
what is the main purpose of secondary lymphoid tissues?
to allow interactions between T cells, B cells, and antigen-presenting cells
what are the functions of the complement system?
punch holes in pathogens, cause inflammation, opsonize pathogens, clear immune complexes
what activates the classical complement pathway?
antibodies
what activates the alternative complement pathway?
spontaneous activation
what forms the C5 convertase in the MBL complement pathway?
C4B, C2A, C3B
what complement components form the MAC?
C5B, C6, C7, C8, C9
what is the effect of binding C3 to the surface of pathogen?
allows recognition by phagocytic cells
what causes most symptoms of inflammation?
increased blood flow and vessel leakage
what is a chemokine?
a cytokine that directs cell movement
what is the way immune cells leave the blood vessels?
they normally express selctins, which provide low-affinity interactions. upon activation, they express integrins, which allow high-affinity binding and exit from the vessel
what is the acute phase reaction?
cytokine signals to the liver to make more immune components
what type of hypersensitivity reaction is a poison ivy rash?
type IV
what causes type II hypersensitivity?
cytotoxic antibodies
why does injection with foreign antibodies cause a hypersensitivity reaction?
you make anti-antibody antibodies, forming immune complexes and causing inflammation
what causes erethroblastosis fetalis?
anti-Rh antibodies in an Rh-negative mother
what causes shock in anaphylaxis?
excessive blood vessel leakiness
how do antihistamines work?
they block histamine receptors
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