2.2 Chronic Inflammation Flashcards
What are the histological characteristics of plasmas cells?
Clock Face nucleus with nucleus that is push off to the side
What is the CD maker that is specific to macrophages?
CD14
What are the the two components of the T cell receptor complex?
CD3 and T cell Receptor
What are the histological characteristics of: PMNs?
multilobed nucleus (5+)
Hypersegmented PMNs are seen in what disease?
B12 deficiency
What are the histological characteristics of: monocytes?
Frosted glass appearance with a kidney shaped nucleus
What cytokine activates macrophages?
IFN-gamma
What are the histological characteristics of: Eosinophils
Bilobed nucleus, packed with large eosinophilic granules of uniform size
What are the components of the NAACP mnemonic for the causes of eosinophilia?
Neoplasia Asthma Allergic processes CT disease Parasites
What are the histological characteristics of: basophils?
Densely packed with basophilic granules containing histamine and leukotrienes
Basophilia is a hallmark of what hematological malignancy?
CML
What is the drug that prevents mast cell degranulation?
Cromolyn sodium
How is CD4+ T cell activation induced?
Extracellular antigen is presented via MHC II, and binding of B7 on APC to Cd28 on CD4 T cells provides 2nd signal
What is the second signal that is needed to activate CD4+ T cells, after/ during binding of MHC class II?
B7 on APCs binds to CD28 on CD4 T cells
What is the role of CD4 T cells?
Secrete cytokines to promote B cell or CD8 T cell activation
What is the function of Th1 cells? What are the cytokines that are secreted in this process?
Secrete IL-2 and IFN-gamma to encourage CD8 T cell proliferation
What is the function of Th2 cells, generally?
Promotes B cell activation
What are the three cytokines produced by the Th2 cells, and what is the function of each?
- IL-4 = (Class switching to IgG and IgE)
- IL-5 = (eosinophil chemotaxis and activation)
- IL-10 = (Inhibits Th1 phenotype)
What is the function of IL-4 secreted by Th2 cells?
Class switching to IgG and IgE
What are the 3 functions of IL-5 secreted by Th2 cells?
- Eosinophils chemotaxis and activation
- Maturation of B cell to plasma cells
- Class switching to IgA
What is the function of IL-10 secreted by Th2 cells?
Inhibits Th1 phenotype
What is the role of IFN-gamma secreted by Th1 cells?
- Macrophage and NK cell activator
- Increases MHC expression
What is the second signal for CD8+ T cell maturation, after MHC class I presentation of an antigen?
IL-2 from CD4+ T cells
How do CD8 T cells mediated cellular killing? (2)
- Secretion of perforins and granzyme induce apoptosis of the target cell
- Binding of FasL on Fas receptor on target cell induces apoptosis
What are the key intracellular mediators of cell death?
Caspases
What are the three ways in which caspases are activated?
- Mito release Cytochrome C
- Fas receptor activation
- CD8 T cells dump granzyme
What are the two antibodies that are expressed on pro B cells?
IgM and IgD
How does B cell activation occur? (2)
- Antigen binds IgM or IgD
- CD40 receptor binding by activated Th2 cell
Is granulomatous inflammation and acute or chronic type of inflammation?
Chronic
What is the KEY cell that defines a granuloma? What are these?
Epithelioid histiocyte (macrophages with abundant pink cytoplasm)
What comprises the rim of granulomas?
Giant cells and a rim of lymphocytes
What are the two major subtypes of granulomas?
Caseating and non caseating
What is the defining feature of caseating granulomas?
Lack central necrosis
Which IBD is characterized by noncaseating granulomas?
Crohn’s disease
What is the histological hallmark of ulcerative colitis?
Crypt abscesses
Stellate granulomas are characteristic of what infectious disease?
Cat scratch disease
How can you differentiate between a necrotic and non-necrotic granulomas histologically?
Non-necrotic will retain their nuclei in the center
What are the two key infectious agents that cause caseating granulomas? What are the two stains that are used to differentiate the two?
TB and fungi
AFB stain = TB
GMS stain = Fungi
AFB stain + in a granuloma = ?
TB
GMS stain + in a granuloma = ?
Fungal cause
What is the first step in making a granuloma?
Macrophages present antigen via MHC II to CD4 T cells
What happens in the process of granuloma formation after macrophages have presented antigen to CD4 T cells via MHC II?
Macrophages secrete IL-12, inducing CD4 T cells to differentiate into Th1 cells
What is the role of Th1 cells in the formation of a granuloma, after they have been induced by macrophage secrete IL-12?
Secrete IFN-gamma to convert macrophages into epithelioid histiocytes and giant cells
What is the cytokine relationship in granuloma formation between macrophages and CD cells?
Macrophages secrete IL-12 to cause CD4 cells to differentiate into Th1, and receive IFN-gamma in return
