Introduction to Tumour Immunology Flashcards
What is ipilimumab?
mAb against CTLA-4
What was the efficacy of ipilimumab for metastatic melanoma with one round of treatment?
more than 20% of patients were alive 10 years later with no evidence of disease vs survival or <10%
What is nivolumab?
mAb against PD-1 receptor
What is the response rate of nivolumab in metastatic melanoma?
50%
what has suggested that the immune system plays a major role in neoplastic development?
patients who are immunsuppressed have a higher risk of cancer and spontaneous regression is rare but well recognised phenomenon- esp. after infectious and/or high febrile episode
What was the first use of modulating hte immune system to treat cancer?
notice of the regression of tumours in cancer patients after erysipelas then intentional infection of cancer patients
How was the the bacterium BCG used in cancer treatment?
effective against superficial bladder cancer
What are Coley’s toxins?
injection of heat-inactivated bacteria into patients with inoperable cancers
What are the non-self antigens that that cells use to recognise cancer cells?
tumour-associated antignes
Give examples of tumour-associated antigens?
products of mutated proto-oncogenes; tumour suppressor genes; overexpressed or aberrantly expressed proteins; tumour antigens produced by oncogenic viruses, altered glycolipids and glycorproteins
What was the first experiment of evidence of immune response to cancer?
a mouse with chemically induced sarcoma had the tumoue resected then retransplanted which resulted in tumour rejection, but if given to naive genetically identical mouse, develops tumour, if give CTLs from original mouse, gets rid of tumour
What demonstrated that immune responses in cancer associated with prognosis to cancer?
presence of tumour infiltrating lymphocytes resulted in better prognosis; with Tregs associated with worse prognosis
What are the hallmarks of cancer?
sustained proliferative signalling; evading growth suppressors; activating invasion and mets; enabling replicative immortality; evasion of cell death and induction of angiogenesis; avoidance of immune destruction
What are the enabling characteristics of cancer?
genome instability and mutation; tumour-promoting inflammation
What are tumour associated antigens?
over-expressed normal genes; products of mutated genes; extopic expression of normal gene products; abnormally glycosylated proteins; viral gene products; novel products of chromosomal instability
What are hte major mechanisms by which CTLs kill target cells?
perforin/granzyme and Fas/FasL
What are the stages of the cancer-immunity cycle?
release of tumour-associated antigens; cancer antigen presenation; priming and activation of T cells; trafficking of T cells to tumours; infiltration of T cells into tumours; reconigiton and killin
What reduces infiltration of t cells into tumours?
VEGF; enfothelin B receptor
What prevents recognition of cancer cells by T cells?
reduced p/MHC on cancer cells
How do traditional cancer drugs contribute to the cancer immunity drugs?
kill tumour cells releasing tumour-associated antigens
What are the stages of cancer immunoediting?
elimination through the cancer-immunity cycle which then provides immune pressure for cells not expressing p/MHC in the equilibrium stage and then escape
Waht si the goal of cancer immunotherapy?
initiate or reinitiate a self-sustaining cycle of cancer immunity enabling it to amplify and propagate but not so as to create n unrestrained autoimmune inflammatory response
Waht can enhance priming and activation in the cancer immunity cycle?
anti-CTLA4
What can enhance infiltration of T cells into tumours?
anti-VEGF
What can enhance recognition of cancer cells by T cells?
CARs
What can enhance immune killing of cancer cells?
anti-PD-1; anti-PD-L1 and IDO inhibitors