Acute Phase Response And Inflammasome Flashcards
Do pathogens vary in size and lifespans?
Yes
When is innate immune protection needed?
When the barriers have failed
Where do worms usually go?
Extracellular e.g. interstitial space, lymph nodes and epithelial surfaces
What are intracellular pathogens and where can these be found?
Things like viruses, protozoa and mycobacterium, they can be found in the cytoplasm of cells and the vesicular area of cells.
What can help protect the body against pathogenes?
Recognition of PAMPs and response of complement, antimicrobial proteins, innate immune cells, adaptive immune system.
What are the cell mediated immunity steps after invasion by pathogens?
Inflammatory inducers, sensor cells (macrophages, neutrophils and dendritic cells), mediators to the target tissue
What cytokines do activated macrophages secrete?
IL-1beta, TNF-alpha, IL-6, CXCL8 and IL-12
What is the local affects of IL-1beta?
Activates vascular endothelium, lymphocytes and increases access to effector cells
What does IL-1beta produce?
IL-6
What does TNF-alpha do?
Activate vascular endothelium and increase vascular permeability which leads to increased entry of IgG, complement and cells to tissues and increases fluid drainage to lymph nodes.
What are the effects of IL-6?
Lymphocyte activation and increased antibody production. It also causes fevers and induces acute phase responses.
What does CXCL8 do?
Recruits neutrophils, basophils and T cells to site of infection
What does IL-12 cells do?
Activates NK cells and induces differentiation of CD4 T cells into T helper cells
What three things stimulate the accute phase response?
TNF-alpha, IL-1beta and IL-6
What do TNF and IL-1 do in the acute phase reaction?
Act of leucocytes and endothelium to induce acute inflammation which induces the expression of IL-6 from leukocytes and other cells types
What does IL-6 do in the acute phase?
Goes to the liver and bind to its receptor to make it produce CRP, SAP, fibrinogen, MBL and MBP and complement. These protiens/peptides rolls are to defend and protect.
What molecules are decreased after a trauma or shock?
Transferrin, albumin and fibronectin
What is an example of a pattern recognition molecules?
These include CRP’s which is composed of 5 subunits and are detectable on the surface of about 4% of normal peripheral blood lymphocytes.
What does the PAMP CRP do?
It binds to phosphocholine which is found on bacterial and fungal cell walls and not on mammalian phosphocholine.
What is the native form of CRP and what can it turn into
Homodimer and can turn into mCRP.
What does native CRP do?
Activates the classical complement pathway, induces phagocytosis, increases IL-6 and TNF-alpha and promotes apoptosis
What does monomeric CRP (mCRP) do?
Recruits circulating leucocytes to areas of inflammation
What does C-reactive protein (CRP) act as?
An opsonin which allows it to be phagocytosed
Apart from CRP what is another PAMP?
Mannose binding lectins
Where is Mannon-binding leptin (MBL) found and what does it bind?
Primarily bound in the liver and binds mannose-containing strcutures (lectin) on micro-organisms and dying host cells
What does MBL function as and what does this activate?
An opsonin so is phagocytoses and this activates the lectin complement pathway
What does the genetically determined variations in MBL serum concentrations influence?
People are more susceptable to infections if they do not have this
Another class of accute phase proteins is complement (C3, C4, C5) - what does this consist of?
Lots of small protiens found in the blood normally functioning as inactive zymogens