Immunity And Cell Responce Flashcards
Passive vs active immunity
Passive quicker
Passive artificial
Passive natural
PA = injected antibodies
PN = antibodies from mother to baby during pregnancy
Active artificial
Active natural
AA = virus injected into person to produce antibodies
AN = naturally caught virus and antibodies produced
Primary response vs secondary resopnce
Primary slow as body fights virus and produces antibodies an clones b cells
Secondary has memory cells so quicker response
Antigens
Proteins on pathogens surface
Receptors
Complementary to specific antibody
Trigger immune response
Humoral response
- b cells
- clonal selection
- production of monoclonal antibodies
Cellular response
- T cells
- phagocytes
Antibody functions and structural features
- bind to make A-A-C with antigen
- trigger immune response
- identify antigen and so virus
AGGLUTINATE PATHOGENS - variable region
- antigen binding site
- disulfide bridges
- hinge protein
- constant regions
Phagocytosis process
- pathogen detected by antigens on surface with receptors from b cells
- pathogen engulfed via endocytosis
- lysosyme enzymes from lysosomes enter vesicle encapsulating pathogen to break it down (phagocytic vacuole)
- pathogen destroyed
- antigens from pathogen taken to membrane of cells in vesicles and presented on the cells surface to trigger immune response
What is a phagocyte
- macrophage
- white blood cell
- engulfs pathogens
After phagocytosis how does the rest of the immune response continue
- phagocytes activate T cells
- receptors proteins in t-lymphocytes bind to compliamentary antigens on APC
- depends on type of T cell
Types of T cells
Helper T - release chemical signals to activate/stimulate phagocytes and Tc cells. Also activate b cells which secrete antibodies
Killer/Cytotoxic T - kill abnormal cells and foreign cells
What happens when T cells activate B cells
- b cells divide
- clonal expansion
- plasma cells and memory cells produced
- antibodies produced
What activates B cells
- T cells chemical signals (interleukins)
- binding to antigen and forming AAC
What is a monoclonal antibody
- antibody specifically programmed to specific antigens
- produced from plasma cells
- identical structures to each other
- can bind to anything programmed to
How to monoclonal antibodies target specific cells e.g. tumour cells
- cancer cells have tumour markers that normal cells dont have
- MA’s can bind to tumour markers
- can attach anti-cancer drugs to antibodies
- when antibodies come into contact with cancer cells they bind to markers
- drug will only accumulate in body where cancer cells are found
- side effects of antibody-based drug are lower than other drugs because they accumulate near specific cells
Targeting particular substances for medical diagnosis
- pregnancy tests
- test for hormone human chorionic gonadotropin (hCG)
- …….tbc
