Which of the following pattern recognition receptors recognise products of necrotic cells
## **Core Concept**
The question tests understanding of pattern recognition receptors (PRRs) and their role in innate immunity, particularly in recognizing damage-associated molecular patterns (DAMPs) released by necrotic cells. PRRs are crucial for the initiation of immune responses.
## **Why the Correct Answer is Right**
The correct answer, **DAMPs (Damage-Associated Molecular Patterns)**, are recognized by various pattern recognition receptors. Necrotic cell death leads to the release of intracellular components, which act as DAMPs. These DAMPs are recognized by PRRs such as **TLRs (Toll-like receptors)**, **NLRs (Nucleotide-binding oligomerization domain-like receptors)**, and **RAGE (Receptor for Advanced Glycosylation End-products)**, triggering an inflammatory response.
## **Why Each Wrong Option is Incorrect**
- **Option A:** While **PAMPs (Pathogen-Associated Molecular Patterns)** are indeed recognized by PRRs, they are primarily associated with pathogens, not necrotic cell products.
- **Option B:** **TLRs (Toll-like receptors)** are a subset of PRRs that can recognize both PAMPs and DAMPs, but the option is too specific and does not broadly cover all PRRs recognizing necrotic cell products.
- **Option C:** This option is blank and does not provide a valid choice.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that **HMGB1 (High Mobility Group Box 1)**, a nuclear protein, can act as a DAMP when released from necrotic cells or activated immune cells. It signals through **TLR2**, **TLR4**, and **RAGE**, promoting inflammation.
## **Correct Answer:** D. DAMPs.