Flashcards
CSIM1.28
Flashcards do conjunto (44)
- 1What is the resting macrophage Response?Resting state – clearing up the 100 million cells that die each second in an adult human
Express few MHC II molecules (?why present dead tissue to T cells) - 2In simple terms, what happens when a body barrier is penetrated in terms of the immune response?If barriers penetrated:
IFNg released by NK cells, T cells
MHC II upregulated
Acts as APC for T cells
Pathogen killing - 3What is the Macrophage Response to Hyperactivation?Pathogen response – PRR (e.g. TLR 4)
Recognises PAMP (e.g. LPS)
Increase reactive O2 molecules
Increase lysosome number
Effective killer - 4What is the bodies response to a few bacteria?Only the innate immune system is used. The bacteria is recognised by preformed, non-specific and broadly specific effectors, and the infectious agents are removed
- 5What cytokines are released by macrophages?IL-1B, TNF-a, IL-6, CXCL8 and IL-12
- 6what are the local effects of IL-1Bit activates vascular endothelium and lymphocytes. There is local tissue destruction, and an increased access of effector cells
- 7What are the local effects of TNF-a?It activates vascular endothelium and increases vascular permiability, which leads to increased entry of IgG complement, and cells to tissues and increased fluid drainage to lymph nodes
- 8What are the local effects of IL-6?Lymphocyte activation, increased antibody production
- 9What are the local effects of CXCL8?Chemotatic factor, recruits neutrophils, basophils, and T cells to site of infection
- 10What are the local effects of IL-12?Activates NK cells, induces the differentiation of CD4 cells into TH1 cells
- 11What are the systemic effects of IL-1B?Fever and production of IL-6
- 12What are the systemic effects of TNF-a?Fever, mobilization of metabolites and shock
- 13What are the systemic effects of IL-6?Fever, induces acute-phase protein production
- 14What happens after TNFa secretion?activated vascular endothelium
increased vascular permeability
increase fluid/complement/cells/Ig to site - 15Describe the processes which take place after firstly a local infection with gram -ve bacteria, and secondly with a systemic reaction to gram -ve bacteria
- 16What are the symptoms of Systemic Inflammatory Response Syndrome (SIRS) ?Temperature dysregulation
(hyper- or hypothermia)
Tachycardia + tachypnoea
White cell response ( or ) - 17What is the NK cell responce?Kill tumour cells, virally infected cells
Secrete IFNγ which activates macrophages
Macrophage secretes TNFα + IL12 which further activate NK cells - 18What are Neutrophils?Bone marrow-derived
Live about 5 days
Professional killers – NOT APC
Attracted to site of infection by TNFa - 19What are resting Dendritic Cells?Bone Marrow derived
Immature
‘sentinel’ – beneath epithelial barriers
Sample environment
Low levels of B7 and MHC expression - 20What are activated dendritic cells?IFNg or TLR stimulation
levels of B7 and MHC expression
Phagocytosis of pathogen at site
Travels to local lymph node - 21What happens to dendritic Cells at the lymph node?Awaits ‘sampling’ by T cell with TCR cognate for antigen – T cell activation
Secretes chemokines to promote monocyte recruitment to site of infection
Survives about 1 week in LN + dies - 22What happens during Interaction of APC + Naïve T Cell?Ag trapped by APC draining LN via afferent lymph
Naïve T cell in blood to LN, enters LN by migrating through post capillary venules
T cell ‘scans’ DC for ‘its’ Ag - 23What happens during activation of Naïve T + B Lymphocytes?Activated in peripheral lymphoid organs
lymph nodes
spleen
gut/bronchial/mucosal -associated lymphoid tissue (GALT, BALT, MALT)
Circulate: blood peripheral lymphoid organs lymphatics blood - 24How do lymphocytes, lymph and antigens travel around the body?
- 25What happens if a T cell is unlikely to find their antigen in the lymph node?leaves via efferent lymph vessel thoracic duct blood
- 26What happens If T cell finds Ag (+ MHC) presented by APCIt adheres to APC, proliferates, differentiates.
“Armed’ effector cell migrates to site of infection - 27What changes occur to dendritic cells and CD4 cells in the absence or presence of early infection?
- 28What happens to dendritic cells and CD4 cells in the presence of viruses and some bacteria vs other pathogens like worms?
- 29What do Naïve B Cells need T cell help with?So they can Proliferate
Form germinal centres
Differentiate into plasma cells - 30How do 2 antigen-specific lymphocytes - Naïve B cell and armed helper (CD4+) T cell - find each other, to initiate a T cell dependent antibody response?B cell re-circulates from blood, through LN through the primary follicle
- 31Describe the process of B cell activation
- 32How do CD4 T Cells activate CD8 T Cells?Armed effector CD4 T cell binds to APC expressing its Ag
Activates APC to express higher levels of co-stimulatory molecules via CD40L (eg B7)
APC then able to stimulate CD8 T cell - 33How do CD4 T Cells activate Macrophages?
- 34What do IFNy & TNFa induce production of?NO and superoxide ions
- 35What is the role of phagocytes?Ag presentation
Clearance of apoptotic cells as immune response controls infection, including most effector cells - 36What do dendritic cells do?activate T cells
provide contemporary ‘snapshot’ of what is happening at the battle front (photojournalists)
recruitment of monocytes as they die, ensures proportionate response - 37What do macrophages do?activated T cells need constant re-stimulation at site of infection, or they apoptose, or become ‘resting’
Whilst macrophages are killers, the APC function allows them to continue to stimulate T cells at the battle front if there is still infection - 38Describe activated B cells?Virgin B cell expresses low levels of B7, MHC
Experienced B cell expresses high levels of B7, MHC and can present antigen to Th cells
BCR have high affinity for antigen, so can concentrate antigen for presentation when there is little antigen around (e.g. early stages of re-infection)
Antigen presentation very fast - < 30 minutes - 39What is the Intrinsic Cell Death Pathway
- 40How are death receptors activated?
- 41Describe Inflammation and Wound Repair?Inflammatory response role in tissue repair
Activation of coagulation cascade
Release of IL-1, TNFα
Recruitment of macrophages, neutrophils to clear cellular debris - 42What happens at the end of inflamation to fix anything that's broken?Release of fibroblast growth factor (FGF), platelet-derived GF (PDGF),and other factors by macrophages promotes new blood vessel growth, fibroblast proliferation and collagen deposition
- 43What are langerhans cells and what do they do?
- 44What are the roles of cytokines in regulating Ig isotype expression?
Informações
- Descrição
- FlashCards sobre CSIM1.28, criado por diseasel.medsoc em 04-05-2015.
- Criado por
- diseasel.medsoc · mai 2015
- Atualizado
- 19 fev 2016
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