pattern recognition receptors (PRRs)

What are pattern recognition receptors (PRRs) and what is their function?

Pattern recognition receptors (PRRs) are sensors that allow the body's cells to detect signs of microbial invasion.

If a cell detects microbial invasion, it produces cytokines to alert other components of the defense system.

How have PRRs changed the understanding of innate immunity?

The discovery of PRRs changed the way immunologists view innate immunity. Previously considered "non-specific," PRRs help cells recognize the general category of an infectious agent, shaping the immune response to that agent.

What are microbe-associated molecular patterns (MAMPs)?

Microbe-associated molecular patterns (MAMPs) are components of certain groups of microbes, such as cell wall-associated compounds, flagellin subunits, and microbial nucleic acid, detected by PRRs.

What are danger-associated molecular patterns (DAMPs) and what do they indicate?

(DAMPs) are molecules that indicate host cell damage. They are recognized by some PRRs and signify potential threats to the host

How do pattern recognition receptors (PRRs) tailor immune responses?

PRRs and the cell types expressing them allow immune responses to be tailored to the category of pathogen and the situation. For example, macrophages produce pro-inflammatory cytokines upon detecting bacterial products, while dendritic cells relay information to the adaptive immune system cells for an appropriate response.

What happens when a virally-infected cell's PRRs detect viral nucleic acid?

When a virally-infected cell's PRRs detect viral nucleic acid, the cell produces interferon, which alerts immune cells to the presence of the virus and promotes an antiviral response in nearby tissue cells.

How do PRR-generated signals influence disease outcomes?

PRR-generated signals from sentinel cells and infected cells can induce protective responses or excessive, damaging responses. Mutations in genes encoding some PRRs can increase the risk of certain inflammatory or autoimmune diseases.

Question: Where are pattern recognition receptors (PRRs) located on or in cells?

PRRs are located in three distinct locations: on the cell surface, in endosomes and phagosomes, and free in the cytoplasm.

How are the locations of pattern recognition receptors (PRRs) helpful?

These locations allow cells to detect the presence of microbes and whether they are inside or outside of a host cell, complementing each other's signals to provoke a stronger immune response.