Immune 5 Flashcards
White blood cells (______) are a _____ ______ of blood, but they are the ____ _____ involved in ______
White blood cells (leukocytes) are a minor constituent of blood - but they are the main cells involved in immunity
Infection and inflammation of tissue e.g skin
(Lecture talking)
- dendritic cells are able to sample antibodies that enter the body
- dendritic cells then take the antibodies to the regional lymph node
- dendtritic cells turn on T cells first which become cytotoxic and kill virus, bacteria and cancer cells by killing the host
- antibodies are the result of vaccination and will protect against pathogen
- also happens in spleen
Antigen sampling an presentation
- dendritic cells are present in major organs
- they phagocytise antigen and process it down to peptides
- DC migrate from organs (e.g skin) to draining lymph node
- they present peptides on MHC to other white blood cells (T cells)
Diagram :)
Adaptive immunity
- dendritic cells present peptides on MHC to T cells
- CD4 cells help B cells make antibody
- CD8 T cells become cytotoxic and kill virus infected cells and cancer cells
CD4 T cells…
Help B cells make antibodies
Cd8 T cells…
Become cytotoxic and kill virus infected cells and cancer cells
Antigen =
Anything that has the potential to be recognised by the immune system
Foreign antigen
- transplants, pathogens, some chemicals
- anything from the outside
Auto (self)-antigen
- immune system normally tolerant to self-antigen
- self antigen may be recognised in autoimmune disorders (e.g rheumatoid arthritis or diabetes type 1)
Purpose antigen uptake - adaptive and innate
- clearance of pathogen (innate response)
- for presentation to T cells (adaptive response)
500 million years ago…
- phagocytes evolved to keep remnants of pathogens and display these to other cells of the immune system
- this was to beginning of the adaptive immune response
Diagram evolution of immunity
- invertebrates ( insects, spiders, jellyfish) have innate immunity only
- vertebrates have both innate and adaptive systems
Note: jawless fish (agnthans: hagfish and lamprey are vertebrates with both innate and adaptive systems. But their a-adaptive system is based on different structures of other vertebrates
Endogenous antigens
- peptides loaded onto MHC class 1 molecules for immune surveillance
MHC-1 antigen processing
- anti genetic proteins are degraded to peptides in cytoplasm
- peptides are imported into the endoplasmic reticulum (ER)
- peptide loading of MHC-1 takes place in the ER
Exogenous antigens
- peptides loaded onto MHC class 11 molecules for immune surveillance
