immuno: tumors simplified info Flashcards
elimination phase
-immune recognizes and eliminates potential tumor cells
-part of normal immunosurveillance
equilibrium phase
-tumor cells undergo mutations to aid in survival
-period of immunoediting
escape phase
-tumors accumulate to higher levels to evade immune system
-uncontrolled growth begins
what phase does the tumor become detectable?
escape phase
cell mediated immunity utilizes which T cells and is activated by what?
CD 8 T cells and NK cells, activated by macrophages
what mediator is produced by CD 8 T cells in cell mediated immunity?
TNF alpha
antibodies on their own __________ kill tumor cells
cannot
antibodies on their own can contribute to killing tumor cells by:
-opsonization
-antibody dependent cell mediated cytotoxicity (ADCC)
two types of tumor antigens:
-tumor specific antigens
-tumor associated antigens
tumor specific antigens (TSA):
are unique to tumor cells, so they are not expressed on normal cells
tumor associated antigens (TAA):
-present on the tumor
-can be found on normal cells just at lower levels
three tumor evasion mechanisms:
- down-regulation of surface molecules
- induction of peripheral tolerance
- creation of physical barriers
how does down-regulation of surface molecules occur?
-loss of MHC I/II expression
-reduced co-stimulator expression
how does peripheral tolerance evade tumors?
-lack of costimulation leading to T cell anergy
-production of cytokines
-recruiting T regulatory cells
what physical barriers are put into place to evade tumor cells?
developing immunoprivileged sites
types of localized treatment for cancer:
-surgical removal
-radiation therapy
types of systemic treatment for cancer:
-chemotherapy
-immunotherapy
-monoclonal Ab that target tumor antigens
autografts
self-tissue transfer
syngenic/isografts
between identical twins
allografts
between different individuals of the same species
xenografts
between different species
lymphoma
cancer of the lymph nodes
leukemia
cancer of blood forming tissue (mainly white blood cells) and primarily affects bone marrow
in leukemia, cells typically proliferate as…
single cells instead of forming solid tumors
graft vs host disease
host is attacked by transplanted T cells
host vs graft disease
transplanted tissue is rejected by host
what cytokine is associated with tumor-induced supression?
IL-10
TNF is secreted by ___________
macrophages
