Integrated immune response II Flashcards
(28 cards)
What activates the complement system on extracellular bacteria, and which pathway [6]
- peptidoglycan (alternative)
- lipopolysaccharide (alternative)
- mannose (lectin)
What is the difference between the alternative and lectin path way [2]
- alternative does not need another cell to activate it
- lectin is activated by cell-cell recognition
Identify the effector functions of the innate immune system acting on extracellular bacteria [3]
- opsonisation
- membrane attack complex (MAC): bacteria lysis
- inflammatory response
What is the difference in response in b cell activated in Ti antigens vs B cells activated Td antigens [2]
- Ti: only produces IgM
- Td: B cell produces IgM and IgG
Identify ways in which the immune system attacks extracellular bacteria [5]
- B cell activation by T cells
- neutralise antibodies
- opsonised phagocytosis
- antitoxins
- complement pathways (C1. C3b, MBL/MASP)
Which Th cell is key in the immune response to bacteria
Th1
Describe how the CD4 Th1 cells fights against extracellular bacteria in the adaptive immune response [3]
- Il-17, TNF etc. lead to inflammation
- IFN-y activates macrophages
- other cytokines induce antibody response
Identify 3 ways in which extracellular bacteria evade the immune response
- inhibit complement activation
- resistance of phagocytosis
- antigenic variation
identify the strategies of Neisseria has to evade humeral immunity [4]
- change surface antigens
- she fragments of membrane, so that immune system attacks blebs instead
- secretes IgA protease, to break down IgA
- Pili changes how bacteriai looks to immune response
Identify ways in which the immune response response to intracellular bacteria [4]
- activation of neutrophils (IL-17 increases ROIs, NO and defensins)
- Il-12 produced by CD4 cells activates TH1, increased macrophage activation and granuloma formation
- CTL activation: TNF, IGNy for inflammation
- neutralising antibodies by plasma cells
Describe the role of Th1 cells in the adaptive immune response against intracellular bacteria [8]
- ROS and NO, respiratory burst
- which activate lysosomal enzymes in phagocytes
- Produce IFN-y and CD40
- activates M1 macrophages
-IL-3
- to stimulate production of monocytes in bone marrow
-CCL2
attracts monocytes to site of infection
Identify ways in which intracellular bacteria evade the immune response [3]
- inhibit formation of phagolysosome
- disrupts phagolysosome to escape into cytoplasm
- produce modified PAMPs, inhibiting PPR signalling
Explain why septic shock is so dangerous [5]
- excess cytokine leads to inflammation
- lots of fluid leaves blood vessels
- rapid decrease in BP
- Circulatory collapse
- intravascular coagulation
Describe the structure of a virus [4]
- genome
- envelope
- capsid
- glycoproteins
Put these in order of peak on a graph of days after viral infection and why
- type I IFN
- antibodies
- Nk CELLS
- cd8 T cells
- Type I IFN: change to alter cell surface membrane to signal something is wrong
- NK cells: kill virally infected cells
- Virus specific CD8+ cells: oil infected cells, specific and targeted
- Antibodies: act on extracellular viruses, remain in body for a long time
Identify the pattern recognition pathways induced by a viral infection [3]
- TLR (3, 7, ,8 ,9)
- RIG-I receptors
- cGAD-STING pathway
Discuss the benefits of seasonal flu vaccines [3]
- prevents suffering for those at high risk
- expensive so can’t offer to everyone
- only predictive
Identify ways in which the immune system can target the influenza virus [6]
- block virus release form mucin
- block virus attachment to host cell
- block virus fusion (viral DNA entering host cell nucleus)
- block virus release from host cells
- trigger FcR mediated effector function
- activate complement pathway
Identify ways in which viruses evade the immune repose [4]
- Interfere with TRAF (HepB)
- Interfere with IRF activation (ebola, HPV)
- Interfere with NF-kB (measles)
- Interfere with STASTs (SARS-coronona)
How does HSV evade the immune response [2]
- inhibits antigen presentation
- interferes with TAP transporter
How does CMV evade the immune response [3]
- inhibits antigen presentation
- inhibits proteasomal activity
- removes MHC I molecules from ER
How does EBV evade the immune response [2]
- inhibition of antigen presentation
- inhibits proteasomal activity
Explain how the immune system has overcome with CMV evasion [3]
- MHC I self presentation act as inhibition response for NK
- any cell that does not have many MHC I self class does not inhibit NK cells
- if not inhibited NK cells will cause lysis of infected cells
Describe the two phases of replication in regards to the HSV [2]
- lytic: cell replicates and lyses host cell causing Cold sores
- lysogenic: integrates into host genome, not actively dividing, hides in sensory neurones
