tumour immunology Flashcards
what is immunotherapy
a treatment that uses the immune system to treat disease eg cancer
sometimes also called biologics
9 factors affecting immune health
chronic stress
physical inacitivity
poor personal hygiene
impaired micro blasts
environmental toxins
lack of sleep
substance use
nutrient deficiencies
poor diet
examples of auto immune diseases
multiple sclerosis
systemic lupus
celiac disease
eczema and psoriasis
hashimotos thyroiditis
asthma
rheumatoid arthritis
describe etiology of cancer
- transformation of germ line cells - inheritable cancers
- transformation of somatic cells - non inheritable cancers
- environmental factors - UV, chemicals, pathogens
hallmarks of cancer (features)
- growth self suffienciy
- evade apoptosis
- ignore anti proliferative signals
- limitless replication potential
- sustained angiogenesis
- invade tissues
- escape immune surveillance
how has the immune system evolved
to discriminate self from non self based on the principle that anything recognised as non self may be dangerous (eg external pathogens)
what is the ultimate goal of tumour imunology
to induce clinically effective anti tumour immune responses that would discriminate between tumour cells and normal cells in cancer patients
what cells mediate
T cells
NKT cells
NK cells
what is cancer immunosurveillance
immune system can recognise and destroy nascent transformed cells
, normal control
what is cancer immunoediting
tumours tend to be genetically unstable, so immune system can kill and also induce changes in the tumour - resulting in tumour escape and recurrence
what are Tumour Specific Antigens (TSA)
only found on tumours
as a result of point mutations or gene rearrangement
derive from viral antigens
what are tumour Associated Antigens (TAA)
found on both normal and tumour cells, but are overexpressed on cancer cells
developed antigens which become depressed
differentiation antigens are tissue specific
altered modification of a protein could be an antigen
difference between TSA and TAA
- tsa only on tumours
- tsa from viral antigens
- taa found on normal and tumour cells but overexpressed on cancer cells
evidence of human tumour immunity
- spontaneous regression - in 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 immunosuppressive, immunodeficiency (aids, neonates), aging etc
evidence for escape 9detectbale tumours)
- immune responses change tumours such that tumours will no longer be seen by the immune system - tumour escape
- tumours change the immune responses by protecting immune suppressor cells - immune evasion
what is the dual function of immune responses
immunosurveillance and immunoediting of tumour
elimination, equilibrium and escaper
what is immunoediting
immune responses can change tumours to be hidden from recognition by the immune system and tumours can promote immune suppression
what is adaptive immunity
to induce an immune response against the tumour that would discriminate against between the tumour and normal cells
what kind of immune are vaccines
active immunotherapy
give 6 types of vaccination
- killed tumour vaccine
- purified tumour vaccine
- professional APC based vaccines
- cytokine and costimulator enhanced vaccines
- dna vaccines
- viral vectors
2 types of passive immunotherapy
- adoptive cellular therapy — t cells
- anti tumour antibodies
what are cellular therapies used for
to activate a patients immune system to attack cancer
and used as a delivery vehicle to target therapeutic genes to attack the tumour
they don’t act directly on cancer cells - they work systemically to activate the body’s immune system
examples of dendritic cells
interstitial cells - liver heart.
langerhan cells of the epidermis
what do dendritic cells do
detect and chew up foreign invader proteins and then present piece of the invaders on their surfaces
how to make a DC vaccine
the blood of the cancer patient is collected and enriched to increase the population of DC
where can macrophages sit
they don’t just sit on top of tumour, they penetrate and accumulate in hypoxia areas
hypoxic cells survive radiotherapy and chemotherapy and regrow
what is a tumour hypoxia
low oxygen
so less blood supply further from outside of tumour so tumour cells adapt to low blood supply and oxygen
problems with tumour hypoxia
- stimulates new vessel growth
- suppresses immune system
- resistant to radio and chemotherapy
- increased tumour hypoxia after therapy
3 general features of tumours
Tumours express antigens that are recognised as foreign by the immune system of the tumour-bearing host
Immune responses frequently fail to prevent growth of tumours
The immune system can be activated by external stimuli to effectively kill tumour cells and eradicate tumours
what are the immune responses to tumours
T lymphocytes
Antibodies
NK cells
Macrophages
define tumour escape
immune responses change tumours such that tumours will no longer be seen by the immune system.
define immune evasion
tumours change the immune responses by promoting immune suppressor cells.
