tumor immunology Flashcards
(44 cards)
prevention of development of most tumors through early destruction of abnormal cells
immune surveillance
immune system in surveillance
- tumors contain lymphoid infiltrate
- spontaneous regression of tumors
- tumors high in neonatal and aged and immunocompromised
what percent are non-tumor cells?
20-80%
immune surveillance depends on the type of tumor inducing agent..
- viral
- chemically induced tumors
- spontaneous mutations
viral immune surveillance
express new viral antigen that become target for immune response
chemically induced tumors immune surveillance
highly antigenic by expressing unique antigens
spontaneous mutations immune surveillance
deletions and rearrangements lead to tumorigenesis
- difficult to respond to because most of the tumor cells have similar antigens as normal
what is the central paradox of tumor immunology?
immunological escape
when does immunological escape occur?
balance between factors favoring tumor growth is favored over destruction
Sneak through, not recognize until growth is established
a. tumor kinetics
b. antigenic modulation
c. antigen masking
d. antigen shedding
a. tumor kinetics
loss of the determinants leading to removal of target antigens that the immune system’s effectors would recognize
a. tumor kinetics
b. antigenic modulation
c. antigen masking
d. antigen shedding
b. antigenic modulation
certain molecules such as sialomucin, bond to membrane masks tumor antigens and prevent recognition
a. tumor kinetics
b. antigenic modulation
c. antigen masking
d. antigen shedding
c. antigen masking
circulating soluble tumor associated antigens capable of compromising t chin of antigen binding sites particularly in the tumor microenvironment
a. tumor kinetics
b. antigenic modulation
c. antigen masking
d. antigen shedding
d. antigen shedding
inhibition of effective immune response by induction of apoptosis of reactive t cells by generation of suppressive cellular and cytokine environment. failure to generate antigen specific t cells
a. tolerance
b. genetic factors
c. inhibitory factors
d. tumor products
a. tolerance
some neoplasm fail to express mhc I antigen. HLA expression is frequently altered in tumors
a. tolerance
b. genetic factors
c. inhibitory factors
d. tumor products
b. genetic factors
immune complexes generated by binding of shaded tumor antigens with antibodies could block immune response by binding directly to t cells or binding to th cells and preventing them to recognize the tumors and delivering help to cytotoxic t cells
a. tolerance
b. genetic factors
c. inhibitory factors
d. tumor products
c. inhibitory factors
secretory products from tumors capable of inhibiting effective immune functions
a. tolerance
b. genetic factors
c. inhibitory factors
d. tumor products
d. tumor products
innate immunity against tumors cells
- NK cells
- PMNs
- monocytes/macrophages
- killer cells
Innate immunity against tumors
cells can kill tumors spontaneously without prior sensitization
Essentially evoked against tumor associated antigens
adaptive immune resposne
adaptive immune response against tumors cells
th cells
cytotoxic cells
cytotoxic t cells and tumors
recognize tumor antigens in association with MHC products
Th cells and tumors
after activation produce interleukins which mediate immune response
t/f amplification of these responses require an optimal supply of cytokines/interleukins
true
