A) What type of cells express pattern recognition receptors (PRRs) ? B) What is the primary role of PRRs in early host defense?

A) Dendritic cells and macrophages, although they are also found in other cells that belong, or not, to the immune system.

B) The innate immune response

Explanation:

The immune system is equipped with specialized receptors for the detection of pathogens such as bacteria or viruses, which are called receptors that recognize patterns (PRRs). These proteins are a key element in the innate system and are expressed primarily in antigen presenting cells, such as dendritic cells and macrophages, although they are also found in other cells that belong, or not, to the immune system.

The innate immune response begins with the recognition of highly conserved molecular structures and present in large groups of microorganisms called 'molecular patterns associated with pathogens' (PAMP). This recognition is done by the 'pattern recognition receptors' (RRP) of the host.

The best known bacterial PAMPs are:

Lipopolysaccharides (LPS)

Peptidoglucan

Lipoteic Acids

Mananas (Mannose)

Bacterial DNA

Double stranded RNA

Glucans

These PAMP are essential for the survival and pathogenicity of bacteria.