Toll-like receptors

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

• What are Toll-like receptors and what is their primary function?
• How do TLRs contribute to the activation of the adaptive immune system?
• Which specific TLR is known for recognizing lipopolysaccharides from Gram-negative bacteria?

Related terms

Major Histocompatibility Complex (MHC):

A set of cell surface proteins essential for acquired immune system to recognize foreign molecules.

Antigen-Presenting Cells (APCs):

Cells that display antigens complexed with MHCs on their surfaces for recognition by T cells.

Cytokines:

Small proteins important in cell signaling released by cells, especially those in the immune system.