Immuno-Oncology: Tumor Antigens, Immune Evasion, and T-Cell Activation

What are TSAs and TAAs?

TSAs are unique to a tumor or tumor type, while TAAs are normal proteins expressed in a way that avoids immune tolerance.

What term is used for unique tumor antigens?

Neoantigen.

List four examples of immune-privileged sites.

The CNS (brain), testes, and eyes.

What is an example of a Tumor Associated Antigen (TAA)?

Tyrosinase.

What is another example of a Tumor Associated Antigen (TAA)?

HER2/Neu.

What is an example of a Tumor Specific Antigen (TSA)?

HPV E6.

Which immune cells are involved in tumor immunity?

Natural Killer (NK) cells.

What pro-inflammatory cytokine is involved in immune response?

IFN-γ.

Which receptor is associated with NK cells?

NKG2D.

What is the function of NKG2D?

It binds to MHC class I on target cells to prevent NK cell attack.

What process is described by Antibody-Dependent Cell Cytotoxicity?

ADCC.

What is the role of M1 and M2 macrophages?

M1 is cytotoxic and anti-tumor, while M2 is immunosuppressive and pro-tumor.

Which cytokine is associated with M1 macrophages?

IL-12.

Which two immunosuppressive cytokines are produced by M2 macrophages?

IL-10 and TGF-β.

What pro-angiogenic factor is produced by tumors?

VEGF (Vascular Endothelial Growth Factor).

What transcription factor is associated with regulatory T cells?

FOXP3.

What are the markers for T regulatory cells?

CD4 and CD25.

How do T regulatory cells suppress immune response?

They block action or kill cells through the release of TGF-β and IL-10.

What chemokine is associated with T regulatory cells?

CCL22.

What is the interaction that activates T cells?

The interaction between the T-cell receptor (TCR) and the MHC/antigenic peptide complex.

What is the role of CD80/86 in T cell activation?

It interacts with CD28 on the T cell.

What is the function of CTLA-4?

It is an inhibitory receptor that competes with CD28 for CD80/86, reducing T-cell activation.

What is a common characteristic of cancer cells regarding β2-microglobulin?

They often lack the expression of β2-microglobulin.

How do cancer cells evade immune detection?

They shed soluble stress proteins (e.g., MICA) to saturate and block NKG2D receptors.

What is the function of PD-L1 in cancer?

They hide their identity from cytotoxic T lymphocytes.

What is the role of E2F in HPV infection?

It is involved in cell cycle regulation.

What is a common outcome of HPV infection?

Hyperplasia followed by Dysplasia.

What is the function of E6 in HPV?

It helps the virus/tumor evade immune responses by altering cytokine signaling.

What is the consequence of E7 promoting cell cycle progression?

It leads to increased glycolysis and cell immortalization.

What is the role of the Fc receptor in immune response?

It binds to antibodies to mediate immune functions.

What is the clinical significance of tumor-associated antigens?

They are generally associated with a poorer patient prognosis.

What is the effect of reactive oxygen and nitrogen species in inflammation?

They contribute to tissue damage and tumor progression.

What is the result of E6 inhibiting MHC transport?

It inhibits the transport of MHC molecules from the Golgi to the cell surface.

What is the function of TGF-β in the immune system?

It is involved in immunosuppression and regulation of immune responses.