Lecture 16: Tumor Immunology Flashcards
True or False: One feature of cancer cells is that arise from a single cell (monoclonal origin)
True
- Therefore: all resulting daughter cells following division of parental cell are identical
True or False: Most tumor cells represent clonal progeny of a single aberrant cell
True
___ causes cell with damaged DNA to undergo apoptosis. Over 50% of cancers have a mutation in this gene.
p53
The main theory surrounding the field of tumor or cancer immunology is that mutations in genes, which result in neoplastic cells, also lead to changes in expressed ___
proteins
- changes protein SHOULD result in recognition of that protein as nonself antigen by immune system
Four pieces of evidence to support immune response to tumors?
1) Immunosuppressed people are more likely to develop tumors
2) CTL/NK cell deficient people have higher incidence of spontaneous tumor formation
3) Solid tumors contain lymphocytes and monocytes
3) Newly transplanted tumors are rejected at higher rate and more rapidly in animals that HAVE BEEN previously exposed to tumors of same type - anamnesic immune response
Which type of immunity is largely mediated by NK cells, which recognize lack or deficiency of self HLA on tumor cells>
Innate Immunity
Tumor cells may be lysed by __ and ___ antibody and complement
IgG and IgM
- however, this is harder if tumor is large or encapsulated in fibrous tissues
Tumor cells may be destroyed by phagocytes if they have been opsonized by __
IgG
True or False: Antibodies can neutralize spread of tumor cells by sterically interfering with tumor cells’ ability to adhere to surrounding tissues
True
In ADCC, ___ antigens induce antibodies (usually IgG) that bind to tumor cell
tumor
In ADCC, __ cell, possessing Fc receptors, attaches to tumor cell through antibody ___
K cell; antibody bridge
K cell is usually a ____
Natural Killer cell
When are substances released from the K cell?
When in close contact with tumor cell
What is the Fc receptor on K cells?
FC-gamma-RII (CD16)
CD8+ Cytotoxic T cells recognize tumor antigens through HLA Class __
HLA Class I
CTL activation is dependent upon Th1 cytokines, such as ___
IL-2
What is the single most important end-line defense mechanism against tumors?
A. CD4+ T cells
B. B cells
C. CD8+ T cells
C. CD8+ T cells