Tumour immunity (year 2) Flashcards
what is a cancer tumour?
damaged cells that don’t undergo apoptosis so metabolism is altered and they grow uncontrollably
what is a tumour?
swelling/lesion formed by an abnormal growth of cells
are tumours always cancerous?
no
what may cause tumours?
oncogenes dysregulation of tumour suppressor genes carcinogens age genetic susceptibility immune deficiency environment infections (especially virus)
what are oncogenes?
protein encoding genes that if they become deregulated trigger onset and development of cancer
give an example of a tumour suppressor gene
P53
define a benign tumour
tumour found at a single site
if a tumour forms secondary tumours, what is it known as?
malignant
how are malignant tumours classified?
based on their origin
where do carcinomas originate from?
epithelial cells
what is the name of tumours that originate from mesenchymal cells or connective tissue?
sarcomas
what is the name give to malignant tumours arising from haematopoietic tissues?
leukaemias or lymphomas
germ cell tumours originate from which tissue?
reproductive tissue
what tissue is the origin of blastoma tumours?
embryonic tissue
what is the name of the tumour associated antigen?
neoantigens
many tumours will induce tolerance, what does this mean?
they won’t induce an immune response
what are the antigen that may be presented by tumours?
tissue specific antigens - normal proteins found in both normal and cancerous cells
viral antigen - foreign proteins due to viral infection
reactivated gene products - normal proteins not usually expect after foetal development
mutated gene products - structurally abnormal proteins
tumours can induce inflammation, how does this promote their formation?
endothelial vessels become more leaky allowing faster spread of tumours
what cells are involved in tumour surveillance?
macrophage
dendritic (for antigen presentation(
CD8 cytotoxic T cells
NK cells
what are the 3 main cells involved in tumour immunity?
NK cell
macrophage
cytotoxic CD8 T cell
what are the two ways tumour may induce immunosuppression?
tumour associated macrophages
immunoregulatory T-cells
how can macrophages promote tumour growth?
can be seen to be under the control of tumours and aid with angiogenesis, tumour invasion of tissue, inflammation, extravasation
how do immunoregulatory T-cells aid tumour growth?
tumours induce IL-10 that blocks T-cell activity
they are also able to induce non-responsive T-cells
what three ways may tumour immunotherapy be approached?
non-specific immune stimulation
passive immunisation
active immunisation
what may be given for non-specific immune stimulation?
microbial, cytokine and cytokine activators
What is the major leukocyte type infiltrating tumours?
macrophages
