UNIT 2, Topic 2C - Immune System Flashcards
What is the cellular immune response (cell-meditated response)?
Where T cells (T lymphocytes) are activated by antigen presenting cells and start an immune response.
Important:
Involves T cells, but cell mediated as it’s only responds to uncertain presenting cells and not antigens to touched from cells and within body fluids.
Give examples of antigen presenting cells (4)
Non-self antigens that are recognised by T cells:
1. Infected body cells present antigens on surface
2. A phagocyte that engulfed and destroyed a pathogen presents its antigens
3. Cells of transplanted organ have different shapes antigens to your own
4. Cancer cells will have abnormal shaped self-cell antigens
What are antigens and what determines their shape?
Proteins molecules on cell-surface membrane responsible for self AND non-self cell recognition (so can act as receptors) & for generating immune response.
The order of amino acids, so primary structure, determines folding in secondary structure; then tertiary structure (forming specific bonds….) creating the antigen binding site.
How do antigens help the immune system?
Allow the immune system to easily identify cells that could be potentially harmful and are non-self.
What are pathogens, give an example
Disease causing microorganisms: virus or bacteria that cause disease
Examples of abnormal body cells
Cancerous cells or ones invaded by a pathogen (infected)
Toxins
Produced by pathogens; cause symptoms to make us feel ill
Note
Body cells from individuals of same species from a transfusion or organ transplant can stimulate and immune response as the antigens may be recognised as non-self.
Which immune response is non-specific and why?
Phagocytosis; the cells involved (phagocytes, a type of WBC) don’t rely on specific shaped complementary receptors to join to the antigens.
