Immune response: Flashcards
What happens in phagocytosis?
= when presented with a pathogen with antigens
= the phagocyte engulf + digest pathogen, into phagovytic vesicle inside the cell- fuses with lysosomes digests the pathogens
= presented antigens from the pathogen on the cell surface membrane
= PATHOGEN IS NOW AN ANTIGEN PRESENTING CELL (APC)
= non-specific response
What are examples of APCs?
= phagocytes
= infected cells
= cancer cells
= transplant cells
=
How does the phagocyte interact with the helper t cell?
= has specific antigen receptor on cell surface membrane
= stimulated by binding to antigen presenting cell
= causes the coloning + defentriation of t helper cells into a larger population and cytoxic t cells.
What is the cell mediated response?
= cytotoxic t cells
= kill infected host cells- antigen presenting cell foreign to the body
What do the t helper cells do?
= stimulates the b cells by binding to t helper cells
What is the structure of b cells?
= specific receptor + specific antibody on cell membrane (ends)
= b cell has to bind to the antigen eitjer on the pathogen or freely about
= found in bone marrow
What does the binding of the b cells does?
= cloning of b cell into memory b cells or plasma cell
Where are memory b cells found?
= blood
= stays in the blood
= secondary immune response if the body is infected by the same pathogen
What do plasma cells do ?
= secretes specific antibodies
= antibodies distratcts the pathogen/nuetralise toxins (antitoxins)
What kind of response does t cells bring?
= cell mediated response
What kind of response does b cells bring?
= humoral response
What is this immune response?
= primary response
= multi-step
= takes a long time- stimulation of t and b cells
What is the secondary response?
= secondary response- single step response of the memory b cells being stimulated to turn into plasma cells to cause the secretion of antibodies
= quicker
= cause the secretion of many more antibodies
How do cytotoxic t-cells kill infected host cells, APC foreign to the body?
releases peroforin: protein that makes holes in the cell surface membrane of foreign APC
= cell membrane becomes freely permeable, cannot regulate what enters and leaves
= cell death: die due to the pores in cell surface membrane, prevents replication and spread of the virus
