🦠microbiology review

Toll-like receptors

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Toll-like receptors (TLRs) are a class of proteins that play a key role in the innate immune system by recognizing molecules frequently found on pathogens. They help initiate immune responses and bridge innate and adaptive immunity.

5 Must Know Facts For Your Next Test

  1. TLRs are located on the surface of immune cells such as macrophages and dendritic cells.
  2. There are several types of TLRs, each recognizing different pathogen-associated molecular patterns (PAMPs).
  3. Activation of TLRs leads to the production of cytokines which aid in the inflammatory response.
  4. TLR4 specifically recognizes lipopolysaccharides (LPS) found on Gram-negative bacteria.
  5. TLRs play a crucial role in antigen presentation by dendritic cells to T cells, thus linking innate and adaptive immunity.

Review Questions

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