Which one of the listed receptor Is a type of receptor on leukocyte that binds to pathogen associated molecular pattern and mediated immune response to bacterial lipopolysaccharide
**Core Concept**
The question tests the understanding of pattern recognition receptors (PRRs) on leukocytes, specifically those that recognize pathogen-associated molecular patterns (PAMPs) and mediate an immune response to bacterial lipopolysaccharide (LPS).
**Why the Correct Answer is Right**
The correct receptor type is Toll-like receptor 4 (TLR4). TLR4 recognizes LPS from Gram-negative bacteria and activates a signaling pathway that leads to the production of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), which trigger an immune response against the pathogen. TLR4 signaling also involves the activation of the myeloid differentiation factor 88 (MyD88) adapter protein and the subsequent activation of nuclear factor kappa B (NF-κB).
**Why Each Wrong Option is Incorrect**
* **Option A:** This receptor is not directly involved in recognizing LPS or mediating an immune response to bacterial lipopolysaccharide.
* **Option B:** While this receptor plays a role in recognizing viral RNA, it is not the primary receptor for LPS recognition.
* **Option C:** This receptor is involved in recognizing bacterial DNA, but it is not the correct receptor for LPS recognition.
**Clinical Pearl / High-Yield Fact**
Toll-like receptors, including TLR4, are critical for recognizing PAMPs and initiating an immune response against pathogens. Dysfunction or abnormal expression of TLR4 has been implicated in various inflammatory and autoimmune diseases, highlighting the importance of this receptor in maintaining immune homeostasis.
**Correct Answer:** C