Correct option is C
Explanation-
Toll-Like Receptors (TLRs) are a family of pattern recognition receptors (PRRs) found on immune cells like macrophages. TLRs detect PAMPs (Pathogen-Associated Molecular Patterns) from bacteria, viruses, fungi, etc., and trigger innate immune responses.
Function of TLR2: TLR2 recognizes a wide range of bacterial components, especially from Gram-positive bacteria. The ligands for TLR2 include - Peptidoglycan, lipoteichoic acid, bacterial lipoproteins, lipopeptides
TLR2 doesn't work alone for all functions. It forms heterodimers with:
1. TLR1 - Triacylated lipopeptides (e.g., bacterial lipoproteins)
2. TLR6 - Diacylated lipopeptides
If TLR2 is knocked out then both TLR2/TLR1 and TLR2/TLR6 signaling will fail. As a result, TLR6 cannot function alone, because TLR6 signaling always requires TLR2.
Incorrect Options-
Option a - TLR9 - Unmethylated CpG DNA (from bacteria/viruses) Independent of TLR2
Option b - TLR3 - Double-stranded viral RNA Independent of TLR2
Option d - TLR5 - Bacterial flagellin Independent of TLR2
Final Answer: Option c: TLR6
