Innate and Adaptive Immunity Flashcards
Innate Immunity
Non-specific and antigen dependent
0-12 hours
Has a 2nd and 1st line of defense
Early stage of infection and no memory
Adaptive Immunity
Specific and antigen dependent
1-7 days
3rd line of defense
Middle and late stage of infection and memory
What are the physical and physiological barriers for innate immunity?
Skin, GI tract, respiratory tract, nasopharynx, cilia, eyelashes and other body hair
Defense mechanisms within innate immune system
Secretions, mucus, bile, gastric acid, saliva, tears, sweat
General immune responses within innate immunity
Inflammation, complement, non-specific cellular responses (leukocytes, complement system)
B cells
Mature in bone marrow
Antibodies that bind to antigens
Hummoral immunity
T cells
Mature in the thymus
T cell receptors and CD4 or CD8
Cell-mediated immunity
Pathogen associated molecular patterns (PAMPs)
Glycoproteins and glycolipids on the surface of diff organisms
Enables innate system to recognize enemies
What does PAMPs include?
Lipopolysaccharides of gram-neg bacteria
Flagellin in the flagella of motile bacteria
Peptidoglycan of gram-positive bacteria
DNA of bacteria and viruses (or RNA)
Glycoproteins of fungi and parasites
What performs phagocytosis?
Neutrophils, dendritic cells and macrophages
Cytokines
Recruit other inflammatory cells
Activate other defensive cells and attract them to the site of invasion
What are the steps in phagocytosis?
- Activation
- Chemotaxis
- Attachment
- Ingestion
- Destruction
- Exocytosis
Complement system
Family of proteins produced in the liver and circulate in blood
Produces biochemical transformation where proteins assist in eliminating pathogens
How do proteins produced by the complement system assist in eliminating pathogens?
- Attracts WBCs to the site
- Tags pathogen to aid phagocytic cells in identifying and engulfing them (bind PAMPs_
- Kills pathogen by creating holes in cell membrane
Complement system pathway
- C4 cleaved to C4a and C4b AND C2 cleaved by MASP2 to form C2b and C2a
- C4b and C2a binds and form C3 convertase
- C3 convertase cleaved C3 into C3a and C3b
- 3a fragment released into fluid and 5 convertase formed with C4b2a3b
- Membrane attack complex (MAC) formed
- C5 convertase cleaved C5 into C5a and C5b
- C5b recruits C6, C7, C8 and C9 to form MAC that induces cell lysis
Membrane attack complex (MAC)
Inserts itself into pathogen membranes, allows extracellular salts and water to enter, causes microbe to swell and burst
What can complement proteins trigger and facilitate?
Trigger the release of histamine from mast cells
Facilitate the removal of antigen-antibody complexes
Pattern recognition receptors (PRRs)
In phagocytic cells on membrane or internal phagosomes
Recognizes PAMPs and send signal to nucleus that activates genes involved in phagocytosis, secretion of antiviral interferons, proinflammatory cytokines and enhanced killer cells
C3 and Factor B deficiency
Sever bacterial infection
C3b-INA, C6 and C8 deficiency
Sever Neisseria infection
Neisseria menpngitidis
Inflammation of the SC and brain
C1, C4 and C2 deficiency
Systemic lupus erythematosus (SLE)
Glomerulonephritis
Polymyositis
C1 inhibitor deficiency
Hereditary angioedema
Signs of inflammation
Dilate BVs
Increase BF and WBCs in area of infection
Redness
Temp. increase
Swelling (leukocytes and edema fluid)
Pain and tenderness (released prostaglandins, histamines)
African swine fever
Hyperemia
Ears reddening
Generalized reddening
