Tumor

Question 1

TUMOR ANTIGENS are……………….,……………..

Answer 1

Tumor Associated Antigens(Oncofetal antigens)

Tumor Specific Antigens

Question 2

programmed to be expressed only during embryogenesis is the AG………………….. and has two types1-…………found high in fetal &low in norm individual &found in patients with hepatomas & teratocarcinoma /2-……………found in cancers of GIT especially colon cancer.
(Both act as timer markers in the patients serum)

Answer 2

(Oncofetal antigens)tumor associated ag

Alpha fetoprotein (AFP)

carcinoembryonic ag(CEA)

Question 3

Tumor antigens may be ……………………….products which may be products of mutated …………….. and ……….. suppressor genes.

• Also, they may be encoded by genomes of ……………. And function as ………………and elicit specific T cell responses that may serve to eradicate the tumor.

Answer 3

mutant cellular gene /oncogenes/tumor

oncogenic viruses/tumor antigens

Question 4

How does the body immunologically respond to ‘altered self’ tissues or tumors? (Immunosurveillance)

Answer 4

CMI→ non-specifickillers ::
NK(no mhc+can kill by ADCC)/monocytes →MQ (ag presentation + cytokines secretion (tnf) can kill by ADCC)/gamma-delta T-cells ((in skin&mucus )prevent tumor spread+kill.)

Question 5

The MQ starts the …Specific IR…
CMI(cc)………..,…………. & HMI …………………..,……………,………..

Answer 5

CMI (cc)
Cytotoxic T cells(tumor infiltrating lymphocytes (TILs))→ virally induced-tumors
/CD4+ T-helper (TH1) cells→ providing cytokines for the activation of MO, NK and the maturation of CTL + Secretion of interferon gamma (INF-gamma)→
oncogenic viruses+ upregulate MHC expression on tumor

HMI
Complement Mediated lysis(alternative and classical)
Opsonization
ADCC- Mediated Lysis

Question 6

TUMOR EVASION OF THE IMMUNE RESPONSE

Host Related Factors→………………..,………………
Tumor Related Factors→ ……………………. , …………… , …………………. , ……………… , ………………. , ………………. , ………….. , ………………

Answer 6

Immunosuppression of the host / Extremes of ages

1-express low levels of class I MHC molecules
2- provide poor co-stimulatory signals
3-Development of tumor in immune privileged sites
4-Resistance of tumor cells to tumoricidal effector pathways
5-Direct immunosuppression by the tumor (IL-10, TGF-B)
6-Antigenic masking
7-antibodies complexed with tumor antigens
8-Modulation of tumor antigens (Antigenic modulation)

Question 7

TUMOR IMMUNOTHERAPY

Answer 7

1-Non-specific stimulation→ Bacterial products(BCG) + thymic hormones & cytokines (IL-2, IL-12 and IFNs)

Question 8

TUMOR IMMUNOTHERAPY

Specific Immunotherapy :
active immunization…………………..,……………………………
Passive immunotherapy…………………,……………………….
……………………….,………………………

Answer 8

Using vaccines prepared from treated tumor cells/Immunization with DNA encoding foreign MHC Ags into the tumor

1- Adoptive cellular immunotherapy → LAK +
bifunctional monoclonal antibodies (MABs

2-Tumor infiltrating lymphocytes (TIL) (specific cells)

3-Therapeutic Monoclonal Antibodies (MABs) (ADCC)

4-IMMUNOTOXINS

5-Genetic Manipulation of Tumor Cells(cytokine genes coding for→
IL-2, TNF, IFN-g, GM-CSF or coding for
costimulatory molecules e.g. B7.1 and B7.2.
• Fogein MHC genes)