Innate Immunity Flashcards
Why can dendritic cells be considered the most important cell in the immune system?
They are a major adaptor between the innate and adaptive immunity, and they have multiple PRRs which really helps to determine the type of microbe that’s present.
What are the cytokines that activated macrophages release?
IL-1 beta, TNF-alpha, IL-6, CXCL8, IL-12
What are the major fever-inducing cytokines involved with the innate immune response?
IL-1 beta, TNF-alpha, and IL-6
Dendritic cells are ________ in origin but play a central role in orchestrating ______ immunity.
myeloid; adaptive
Innate lymphoid cells are _______ by morphology.
lymphocyte
How do innate lymphoid cells differ from T and B-cells? (3 ways)
1) Absence of RAG gene - no DNA rearrangement
2) Lack of myeloid cells/DC marker
3) Lymphoid morphology
What are the 3 types of innate lymphoid cells we talked about, and which type of immunity do they confer?
1) ILC1 (NKCs): immunity to viruses, intracellular bacteria, and parasites
2) ILC2: immunity to helminths
3) ILC3: immunity to extracellular bacteria
Natural killer cells are derived from ______ progenitors.
lymphoid
Are natural killer cell receptors diversified?
No! They just look for cells with altered expression of self-antigen. If there is no presentation of self-antigen, then NK cells are triggered to kill the cell.
What are the 4 classes of PRRs?
1) Toll-like receptors: facilitate recognition of microbes based on positionality (IC vs. EC)
2) NOD-like receptors: exist in cytosol and recognize intracellular microbes
3) C-type lectin receptors: recognize sugars
4) Rig-I-like receptors: recognize viral RNA structures intracellularly
Although not all PRRs activate cellular gene expression by the same pathway, most induce the production of ____________ to enhance inflammatory responses.
a secondary signaling molecule
Explain the dimerization of TLRs.
TLR-1 and TLR-2 have a binding site for lipid side chains of triacyl lipopeptides. Binding of each TLR to the same lipopeptide induces dimerization, bringing their cytoplasmic TIR domains in close proximity. This facilitates the intracellular response to begin an effector molecule cascade.
What is the ultimate result of the innate response?
inflammation!
What is the significance of mannose recognition by PRR?
Mannose-binding lectin (MBL) recognizes the terminal mannose of a bacterial glycoprotein, and it induces complement activation.
We experience inflammation due to…
- alteration of blood flow
- increased vascular permeability
- infiltration of WBCs into area of reaction
