PRR Function of Innate Immune Receptors in Recognition of Bacteria or Bacterial Ligands

Recognition of a bacterial attack is the first and the most important step in clearing the bacteria from the body of the host. Towards this, the host innate immune system employs pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs), nucleotide-binding leucine-rich repeat-containing receptors (NLRs) and scavenger receptors (SRs) present mostly in innate immune cells. These receptors sense the presence of bacteria and help in spreading the signal to the host, which results in recruitment of other immune cells leading to the elimination of the bacteria from the system. Since their discovery, a lot has been established about these receptors. Their role has been elucidated not only in pathogen recognition but also in eradication of the dead cells from the system. This review is focussed mainly on their role in the bacterial recognition and how these receptors play a role in eliciting an immune response against bacteria in the host.