Tumor Immunology Flashcards
Paraneoplastic syndromes are __________.
syndromes in which patients develop secondary, organ-specific symptoms in response to cancer; most commonly, cancers can present with antibodies to tumor cells that also attack parathyroid cells
Interestingly, athymic nude mice do not _________; they will do so, however, if ________.
spontaneously develop cancer; cancer cells are transplanted to them
The most common way cancers are killed is __________.
immune-mediated elimination
Before cancer growth, cancers must __________.
undergo a period of equilibrium with the immune system and then ultimately escape
By what ways do tumors down regulate the immune system?
They (1) decrease their MHC expression, which helps them hide from CTLs; (2) increase Treg generation, which suppresses overall immune response; (3) generate M2, immunosuppressive macrophages; (4) generate a hypoxic environment that decreases the immune response; (5) secrete immunosuppressive cytokines; (6) increase PD-L1; and (7) increase CTLA-4 ligands B7-1 and B7-2
How are driver mutations different from passenger mutations (in cancer cells)?
Driver mutations are genes that cause cancer (oncogenes and tumor suppressors), while passenger mutations are all other mutations; generally, passenger mutations are deleterious.
The more mutations a cancer has, the _______.
better the prognosis
What are neoepitopes?
Neoepitopes are epitopes that cancer cells express; they are targets for monoclonal antibody.
What two T cell receptors interact with CD80/CD86?
CD28 (which stimulates T cell growth) and CTLA-4 (which inhibits T cell growth)
Following the initial cell interactions (involving CD80/CD86), T cells express __________.
PD-1 (an inhibitory receptor)
Tumors that don’t express PD-L1 don’t respond to _________ as well as those that do.
antibody therapay
List some of the evidence that supports the theory that the immune system tries to fight cancer.
(1) Researchers have found T lymphocytes that attack tumor cells; (2) immunocompromised people have higher rates of cancer; (3) some cancers spontaneously regress; and (4) people develop antibodies to cancer that can lead to paraneoplastic syndromes
What cancer usually has the most mutations?
Melanoma; one patient’s cancer was found to have 3,000 protein-altering mutations
Why are tumors good targets for ADCC?
Because natural killer cells don’t kill cells with lots of MHC I; the thought behind that is that MHC I killing is the CTLs’ job. Because tumors down-regulate MHC I to escape killing, then they are good targets for NKs.
Which cells normally express PD-L1?
APCs
