MICR223_L17_pattern-recognition

What are Pattern Recognition Receptors (PRR)?

PRRs are components of the immune system that recognize and respond to pathogens and commensals.

How do PRRs distinguish between pathogens and commensals?

PRRs do not effectively distinguish between commensals and pathogens, as both can trigger the immune response.

What is the function of TLR (Toll-like Receptors)?

TLRs sense a variety of microbial molecules and signal for proinflammatory gene transcription.

Where is TLR-5 located, and what does it detect?

TLR-5 is present on baso-lateral membranes of gut epithelium and detects flagella.

What structures do PRRs recognize?

PRRs recognize PAMPs, which are conserved structures like flagella, bacterial DNA, and LPS.

What is the ultimate outcome of PRR triggering?

The ultimate outcome is stimulation of the immune system.

How do TLRs signal?

TLRs signal through dimerization, recruiting adaptor proteins that activate transcription factors.

What does the inflammasome produce?

The inflammasome produces and releases mature IL-1 and IL-18.

What is an example of a DAMP that activates the inflammasome?

Uric acid produced during gout is an example of a DAMP.

What happens once the inflammasome is activated?

The inflammasome recruits caspase 1, which converts pro-IL-1 and pro-IL-18 into active forms.

How do IL-1 and IL-18 differ in terms of secretion?

IL-1 and IL-18 lack signal sequences and are secreted via non-classical mechanisms.

What is pyroptosis in the context of the inflammasome?

Pyroptosis is a form of cell death resulting from inflammasome activation.

What types of responses do nucleic acid sensors induce?

Nucleic acid sensors induce an IFN type I response that protects against virus infection.

What kind of proteins are NOD-like receptors (NLR)?

NLR are a family of cytosolic proteins activated by intracellular PAMPs or DAMPs.

What does Gasdermin D do during inflammasome activation?

Gasdermin D is cleaved to form pores through which IL-1 and IL-18 can escape.

What condition is associated with the activation of the NLRP3 inflammasome?

The NLRP3 inflammasome is associated with gout.

What is the significance of reactive oxygen species (ROS) in inflammasome activation?

ROS are implicated in the triggering of the inflammasome during inflammation.

What ethnic groups have the highest prevalence of gout in New Zealand?

Pacific people have the highest prevalence, with Māori having higher rates than non-Māori/Pacific.

What genetic variant is associated with hyperuricaemia and gout susceptibility?

A genetic variant within the GLUT9 gene is associated with susceptibility to hyperuricaemia and gout.

How might high uric acid levels have offered a selective advantage historically?

High uric acid levels may have helped maintain blood pressure under low salt dietary conditions.

What role does IL-1 and IL-18 play in vaccines?

IL-1 and IL-18 encourage adaptive immune responses in vaccine design.

How does the inflammasome relate to autoimmune diseases?

The inflammasome is important in autoimmune diseases such as gout and inflammatory bowel disease.

What happens during ‘priming’ of the NLRP3 inflammasome?

Priming involves gene transcription of NLRP3, pro-IL-1, and pro-IL-18.

What can lead to caspase 1 activation in inflammasome signaling?

The first signal is TLR stimulation, leading to transcription factor activation.

What do macrophages do regarding IL-1 and IL-18 secretion without cell death?

Macrophages can release IL-1 and IL-18 via GSDMD pores without undergoing cell death.

What is the physiological effect of increased serum urate levels later in life?

Increased serum urate is associated with enhanced cognitive function.

What is a key characteristic of adaptive immune response receptors compared to PRRs?

Adaptive immune receptors like BCR and TCR are identical on each cell, while PRRs can vary between cells.

What does Gasdermin D facilitate during cell stress?

Gasdermin D facilitates pore formation that allows IL-1 and IL-18 release.

What is one method by which IL-1 and IL-18 can be secreted from cells?

IL-1 and IL-18 can be secreted through pyroptosis or Gasdermin D pore release.

Why is TLR signaling crucial for the inflammasome?

TLR signaling is essential for priming the genes needed for the inflammasome, including pro-IL-1 and pro-IL-18.