Term
| Two cell types that function as phagocytes |
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Definition
| Neutrophils and macrophages |
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Term
| Macrophages in lymph and spleen are called? |
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Definition
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Term
| Macrophages in bone marrow are called? |
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Definition
|
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Term
| Macrophages in synovium are called? |
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Definition
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Term
| Two ways phagocytes can recognize pathogens? |
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Definition
Direct or opsonin-mediated.
Direct interaction refers to recognition of antigens w/o an intermediary protein
Indirect recognition refers to interaction of intermediary protein on an antigen, with a receptor on the phagocyte |
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Term
| Direct recognition of pathogens occurs how? |
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Definition
Via PRRs (pattern recognition receptors).
Their ligands are PAMPS (pattern activation molecular patterns).
Receptors trigger cascades of biochemical events that lead to secretion of inflammatory cytokines, and other cellular responses associated with the innate immune response. |
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Term
| Mutation in what receptor has been associated with Crohn's disease? |
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Definition
| Nod 2 protein, which is a type of NLR (type of PRR or pattern recognition receptor) |
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Term
| What are TLRs (toll-like receptors)? |
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Definition
| Are membrane bound receptors expressed on a various cell types including macrophages, dendritic cells, and neutrophils. |
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Term
| What is indirect recognition by phagocytes? |
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Definition
Is called opsonin-mediated phagocytosis.
Refers to interaction of intermediary protein on antigen with receptor on phagocyte.
Phagocytes recognize the opsonins that bind to pathogens. |
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Term
| Opsonins are products of what three things? |
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Definition
1) Complement activation
2)B-cell activation
3)Cytokine mediated activation of hepatocytes (ex: CRP)
Interaction of any of these pathogen-bound opsonins triggers process of phagocytosis |
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Term
| Receptor-Opsonin pairings for the following are? |
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Definition
FcGamma: FcGammaR
CRP: CRP-BS
C3b: C3b-CR1 |
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Term
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Definition
| Are vesicles that contain the engulfed pathogen. |
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Term
| What are the weapons that phagocyte uses? |
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Definition
Lysosomal enzymes
Reactive oxygen intermediates
Reactive nitrogen intermediates |
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Term
| Lysosomal granules are discharged into what? |
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Definition
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Term
| Lysosomal granules contain what enzymes? |
|
Definition
Lactoferrin
Lysozyme
Defensins
Myeloperoxidase |
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Term
What do these 4 things secrete?
Lactoferrin
Lysozyme
Defensins
Myeloperoxidase |
|
Definition
Lactoferrin - Binds iron, thereby removing an essential ingredient for microbial growth
Lysozyme - Destroys muramic acid in bacterial cell walls
Defensins - Permeabilize bacterial and fungal membranes
Myeloperoxidase - Generates hypochlorite, a antimicrobial that mediates its function by halogenating bacterial cell walls |
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Term
| Phagocytosis triggers what? |
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Definition
| Assembly of NADPH Oxidase on the phagocytic vacuole, the phagosome. |
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Term
| What are the reactive oxygen species (ROS) that are generated by NADPH oxidase? |
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Definition
Hydrogen peroxide
Hydroxyl radical
Hydroxyl ion
Hypochlorite |
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Term
| What two cytokines enhance activation of NADPH oxidase? |
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Definition
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Term
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Definition
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Term
| Synthesis of nitric oxide requires what enzyme? |
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Definition
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Term
| Nitric oxide is toxic to what? |
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Definition
Both microbes and the HOST TISSUE (phagocytes producing it).
Short half-life confers some protection. |
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Term
| Nitric oxide reacts with ROIs to produce what? |
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Definition
| Reactive nitrogen intermediates (RNIs) |
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Term
| NO and RNIs are important to combat what pathogens? |
|
Definition
Intracellular pathogens that are resistant to ROIs and lysosomal enzymes like:
Mycobacteria species
Intracellular bacteria
Leishmania species |
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Term
| Induction of iNOS requires what two signals? |
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Definition
1) Priming signal delivered by bacterial products or TNF
2)Second signal delivered by IFNgamma |
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Term
| What cytokines down-regulate iNOS? |
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Definition
TGF-B (most effective)
IL-10
IL-4 |
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Term
| MCP-1 (CCL2) is a chemoattractant for what? |
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Definition
| Monocytes and macrophages |
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Term
| IL-8 (CXCL8) is a chemoattractant for what? |
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Definition
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|
Term
| Activated macrophages secrete what cytokines? |
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Definition
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|
Term
| What is the NALP3 inflammasome? |
|
Definition
| A large intracellular complex that is assembled following binding of damaged intracellular molecules or intracellular microbial products. Binding occurs via PAMPS or DAMPS. |
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Term
| Role of the NALP3 Inflammasome? |
|
Definition
Important role in innate immunity
Pro-Caspase 1 zymogen is turned to its active form Caspase 1 (IL-1B converting enzyme).
This causes Pro-IL-1B and Pro-IL-18 to be converted to IL-1B and IL-18B |
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Term
| CD200Rs are expressed where? |
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Definition
| Primary of cells of myeloid lineage, but also on CD4 and CD8 T-cells. |
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|
Term
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Definition
Is the ligand for CD200R.
It is a membrane glycoprotein that suppresses immune activity via its receptor.
Is expresses on T-cells, B-cells, and dendritic cells. |
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Term
| Mice CD-200 knock-out are more susceptible to what type of problems? |
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Definition
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|
Term
| What cells are mainly effective against parasites, mostly helminths? |
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Definition
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|
Term
| How do eosinophils combat parasites (helminths)? |
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Definition
They have a FCeR that bind to IgE antibodies which are bound to epitopes on helmniths
Eosinophils are degranulated and several molecules are released such as MBP (major basic protein) and ECP (eosinophil cationic protein). |
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Term
| NK cells are good at killing what? |
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Definition
| Viral infections and some tumors |
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Term
| Class 1 MHC can be upregulated by what cytokines? |
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Definition
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|
Term
| What 3 things decrease expression of Class 1 MHC-self peptide expression on cell surfaces? |
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Definition
Stress
Some viral infections
Some tumors |
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Term
| What is ADCC (antibody dependent cell mediated cytotoxicity) ? |
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Definition
| Diff. Abs recognize diff. viral proteins embedded in the cell membrane of an infected cell, and then kill that cell. |
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Term
| How do NK cells kill microbes? |
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Definition
| Leads to release of lytic granules that contain perforin and granzymes, which play a role in cell destruction |
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Term
| What causes NK cells to relase IFNgamma? |
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Definition
| Stimulation by IL-12 with IL-15 or IL-18 |
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Term
| What enhances cytotoxicity of NK cells? |
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Definition
IL-2
NK cells then are referred to as LAK cells (lymphokine activated killer cells). |
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Term
| What combination of cytokines leads to greater amount of IFNgamma secretion? |
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Definition
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|
Term
| What cells are the best APCs? |
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Definition
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Term
| What is the first signal in T-cell activation? |
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Definition
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Term
| What plays a role in mobilization and activation of dendritic cells? |
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Definition
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Term
| Recently, dendritic cells have been used to combat what? |
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Definition
| Used as "vaccines" in cancer treatment |
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Term
| What anaphylatoxins are released following complement activation? |
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Definition
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Term
| CR5a binds what complement fragment? |
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Definition
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|
Term
| Cross-linking leads to what? |
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Definition
| Release of histamine etc... |
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Term
| What happens when CD200 binds to CD200R1 and its isoforms? |
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Definition
| Leads to suppression of T-cell mediated immune responses |
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