Immune System L31 Flashcards
What happens first in infection at a wound
Phagocytosis, complement, amp release at epithelial, apc (dendritic)
Where does dendritic apc go to and what happens
Down lymphatics to lymph node and activates B and T cells via antigen/MHC
These then released eg antibodies and Th cells and this causes attraction of phagocytes, NK, eosinophils etc
How are intracellular cytoplasmic pathogens killed
Cytotoxic T cells
NK cells
(Both have perforin and granzymes)
How are intracellular vesicle pathogens dealt with
T cell or NK cell activation of macrophages
What is indirect pathogenicity
Symptoms from immune reaction
Give examples of indirect pathogenicity via immune system
Host cell - antibody response
Immune complexes (antigen antibody clumps)
Cytotoxic damage to normal host cells
What are the 2 types of leprocy
Tuberculoid (mild)
Lepromatous (severe)
Why is tuberculoid leprocy easier to deal with
Normal T cell response, local inflammation, TH1 response eg via IFN y = phagocytosis
Which antibody is high with lepromatous leprosy
IgG
Which Th response happens with lepromatous leprocy which is inappropriate
Th2- causes IgE switching and mast cell activation etc and eosinophils
Eg via IL 4
What is difference between primary and secondary immunodeficiency
Primary - rare genetic defect
Secondary- immunosuppressives, stress, pregnant
Why would things like herpes 8 and hepatitis C cause tumours in immunodeficiency
Lack of ability for NK cells/ cytotoxic cells to fight off tumour cells
Herpes and hep can introduce oncogenes to grow Tumour cells
Which deficiency causes lack of B cells and antibodies to fight extracellular/ free pathogens
X linked a gamma globulin anaemia
What would grow if there was iga deficiency
Pathogens in secretory areas eg respiratory tract
What is immunopathology
Excessive immune response eg autoimmune, allergy , infection
How is covid an immunopathology
Causes unregulated cytokine storm when epithelial cells engulfed
Cause low lymphophenia in blood (go to tissues)
What are type 1-3 hypersensitivity caused by
Antibodies
Give example of type 1 hypersensitivity via antibodies
Ige over stimulation via allergy antigens eg pollen to bind to fc receptors on mast cells to release histamine
What can type 1 hypersensitivity usually cause
Anaphylaxis as too much vasodilation , bronchospasm via histamine
Give an example of type II hypersensitivity
Crossing of igG eg anti rhesus antibody to placenta and child with rhesus +ve causes anemia (lysis of rbc)
What is a disease caused by type III sensitivity
Lupus
What happens in type III lupus
Autoantibodies IGG form complex with host dna antigens and cause deposits = rash etc
What is type IV hypersensitivity
Cell mediated attack
What is an example of type IV hypersensitivity
Diabetes
Pancreatic B cells with mhc 1 are killed by cytotoxic CD8
Who are autoimmune diseases more common in
Females
NK and cytotoxic kill tumour cells, how have vaccines been made for tumour cells
Taken antigens from tumour cell and delivered it to form antibodies against it
Which vaccine has been used for tumour shrinkage
BCG (TB)
