immunology Flashcards
name 9 factors affecting immune health
- Chronic stress
- Physical inactivity or excessive exercise
- Poor personal hygiene
- Impaired microbiota
- Environmental toxins
- Lack of sleep
- Substance use
- Nutrient deficiencies
- Poor diet
describe the etiology of cancer
Transformation of germline cells: inheritable cancers (<10%, Rb, BRCA1, 2)
Transformation of somatic cells: noninheritable cancers (>90%)
Environmental factors:
UV (skin cancer), chemicals (lung cancer), pathogens (HPV causes cervical cancer, helicobacter causes stomach cancer)
key recognisable features of cancer
Growth self-sufficiency
Evade apoptosis
Ignore anti-proliferative signals
Limitless replication potential
Sustained angiogenesis
Invade tissues
Escape immune surveillance
describe the term cancer immunosurveilance
Immune system can recognize and destroy nascent transformed cells, normal control
describe cancer immunoediting
Tumours tend to be genetically unstable; thus immune system can kill and also induce changes in the tumour resulting in tumour escape and recurrence
what are the two types of tumour antigens?
Tumour specific antigens ( TSA)
Tumour associated antigens ( TAA)
describe tumour specific antigens
Are only found on tumours
As a result of point mutations or gene rearrangement
Derive from viral antigens
describe tumour associated antigens
Found on both normal and tumour cells, but are overexpressed on cancer cells
Developmental antigens which become derepressed. (CEA)
Differentiation antigens are tissue specific
Altered modification of a protein could be an antigen
evidence for human tumour immunity
-Spontaneous regression: melanoma, lymphoma
-Regression of metastases after removal of primary tumour: pulmonary metastases from renal carcinoma
Infiltration of tumours by lymphocytes and macrophages: melanoma and breast cancer
Lymphocyte proliferation in draining lymph nodes
Higher incidence of cancer after immunosuppression, immunodeficiency (AIDS, neonates), aging, etc.
name the 2 pieces of evidence for Escape ( detectable tumours
tumour escape
immune evasion
explain tumour escape
Immune responses change tumours such that tumours will no longer be seen by the immune system
explain immune evasion
Tumours change the immune responses by promoting immune suppressor cells
define the term immunotherapy
Learn how to harness the immune system to kill tumours
what are the types of immunotherapy
active
passive
how are tumours killed without killing normal cells?
Adaptive immunity
describe adaptive immunity
To induce an immune response against the tumour that would discriminate between the tumour and normal cells
2 examples of passive immunotherapy
- Adoptive Cellular Therapy (T cells)
2.Anti-tumour Antibodies (Her-2/Neu, CD20, CD10, CEA, CA-125, GD3 ganglioside)
give 6 possible vaccinations you could get in active immunotherapy
Killed tumour vaccine
Purified tumour antigens
Professional APC-based vaccines
Cytokine- and costimulator-enhanced vaccines
DNA vaccines
Viral vectors
describe cell based therapy
- can be used to activate a patient’s immune system to attack cancer.
-do not act directly on cancer cells. Instead, they work systemically to activate the body’s immune system.
-can also be used as delivery vehicle to target therapeutic genes to attack the tumour
describe dendritic cells
Found throughout the body (0.1-0.5%)
Interstitial cells (Liver, heart, liver), Langerhans cells of the epidermis.
Detect and chew up foreign “invader” proteins and then “present” piece of the invaders on their surface.
To make a DC vaccine, the blood of the cancer patient is collected and enriched to increase the population of DC.
describe T cell therapy
where can macrophages accumulate?
in hypoxic areas
what can macrophages survive?
radiotherapy
chemotherapy
and then regrow
describe tumour hypoxia
- means low oxygen
-prominent feature of malignant tumours
-Inability of the blood supply to keep up with growing tumour cells
-Hypoxic tumour cells adapt to low oxygen
