BIOL 465 Midterm 2 Flashcards
What are the 3 main types of T cells in the innate immune system?
- Helper (TH)
- Regulatory (Treg)
- Cytotoxic (TC)
What are the 3 main components of the innate (cellular) immune system?
- Antigen-presenting cells (dendritic cells, macrophages)
- Cytotoxic cells (NK cells, macrophages)
- Proteins (complement system)
How do Treg cells help to regulate the adaptive immune system?
By inhibiting TH and TC cells.
What 2 processes are stimulated by TH cells?
- Proliferation of plasma cells (B cells and other humoral immune cells)
- Killing of target cells by TC cells
What does HIF stand for (as in HIF1 & HIF2)?
Hypoxia-inducible factor.
What type of cell differentiates to become a tumour-associated macrophage (TAM)?
Monocytes.
What are the most abundant immune cells involved in tumour development?
Macrophages.
How do TAMs initially respond to the levels of hypoxia found in tumours?
By upregulating transcription factors, including HIF1 & HIF2, that in turn activate genes that promote tumour growth and proliferation.
What are the 4 main types of genes activated by transcription factors upregulated in macrophages in response to hypoxia in tumours?
- Mitogenic genes
- Proinvasive genes
- Proangiogenic genes
- Prometastatic genes
What are the 2 main molecules recognized by anti-tumour macrophages as part of normal innate immunity?
- Lipopolysaccharide (LPS)
- Interferon-γ (INF-γ)
What is the main function of anti-tumour macrophages (MACs) in the normal innate immune response?
To recognize LPS or INF-γ as a marker of foreign or abnormal material and to phagocytize an infectious pathogen or tumour cell once recognized.
What type of macrophage responds to LPS or INF-γ?
Anti-tumour macrophages (MACs).
What type of macrophage responds to hypoxia with an area of rapid tissue growth?
Tumour-associated macrophages (TAMs).
Why does hypoxia trigger an innate immune response by TAMs?
TAMs recognize the hypoxic tissue as a wound site and are attracted to it in order to fix the wound.
What is interleukin-10 (IL-10)?
A proangiogenic cytokine, released by TAMs in areas of hypoxia, that stimulates HIF1α and VEGF to promote angiogenesis.